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BACKGROUND OF INVENTION
[0001] 1. Field of Invention
[0002] This invention relates generally to global positioning systems (GPS) and, in particular, GPS systems used for emergency location of cellular handsets.
[0003] 2. Description of Related Art
[0004] Various methods have been put forth in order to address the need for an emergency cellular location system. One method utilizes a number of cell transmission towers to locate a cell phone user by standard triangulation methods. This method is limited due to the low level of handset power in that it is unlikely that three or more towers will receive the signal needed for triangulation. Another method utilizes the GPS system, whereby a GPS receiver is located in the cell handset. Like the cell-tower system, this method is limited because of the lack of transmitted power, but also due to the distance of the satellite mounted transmitters from the handset receiver.
SUMMARY OF INVENTION
[0005] A unique method is introduced herein, whereby local signals are utilized to locate an unknown-location signal receiver. In this method, three or more known-location signal receivers are used to locate one or more unknown-location transmitters of signals of greater than zero bandwidth by way of delay differentiation. A combination of three or more signal transmitters comprising one or more unknown-location transmitters are then utilized to locate the unknown-location signal receiver.
[0006] In one embodiment, three or more standard television and radio signals are located using three or more cell sites and, with timing referenced to the signals received by the cell sites, a cellular handset is located. In another embodiment, the delay from one or more cell sites to the hand set is utilized, along with one or more unknown-location receiver to locate the cellular handset. A third embodiment utilizes mobile transmitters, such as emergency or police band radios to locate and utilize for handset location. A fourth embodiment utilizes other cellular handsets in order to locate a cellular handset. The preferred embodiment employs all four of these means to locate a cellular handset.
[0007] One method introduced herein comprises 1) measuring the difference of delay from one or more unknown-location signal transmitters to three or more known-location signal receivers. 2) utilizing said delay difference measurements to locate the one or more unknown-location signal transmitters. 3) locating an unknown-location signal receiver by way of a combination of three or more signal transmitters comprising one or more unknown-location transmitter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows the constellation of possible locations using known-location signal receivers AB, AC, and BC for various differences in time with respect to the transmission time from a first known-location signal receiver to a second known-location signal receiver.
[0009] FIG. 2 shows the location of a specific point (x) using any two of the vector sets.
[0010] FIG. 3 shows a point (x) located within three points A, B, and C.
[0011] FIG. 4 shows a point (x) located outside three points A, B, and C.
[0012] FIG. 5 shows three cell towers (T 1 ,T 2 ,T 3 ) and three cellular handsets (H 1 ,H 2 ,H 3 ).
[0013] FIG. 6 shows another method wherein a first handset receives signals from two towers and a second handset receives a signal from a third tower.
[0014] FIG. 7 shows multiple handsets used to indirectly locate a handset, whereby location of the handset to be found can be accomplished by locating other handsets within the cell, an then using the other handsets as known-location transmitters.
DETAILED DESCRIPTION OF THE INVENTION
[0015] In the first embodiment, a remote processing station sends a request to three or more known-location signal receivers to send return signals in order to measure the delay from each known-location signal receiver to the processing station. Each known-location signal receiver receives signals from three or more unknown-location transmitters and sends the signals from the unknown-location transmitters to the remote processing station. The processing station then measures the difference in time between the signals received by the known-location signal receivers from each unknown-location transmitter by subtracting the respective transmission line delays. The net delay differences from each unknown-location transmitter to each of the known-location signal receivers are used to locate each unknown-location transmitter at a point in space.
[0016] FIG. 1 shows the constellation of possible locations using known-location signal receivers AB, AC, and BC for various differences in time with respect to the transmission time from a first known-location signal receiver to a second known-location signal receiver. As an example, the constellation labeled 0.8 is represents a set of points where the transmission time from any point on the arc to point A is equal to the transmission time to point B plus 80% of the transmission time from point A to point B.
[0017] FIG. 2 shows the location of a specific point (x) using any two of the vector sets. Using vector sets AB and AC, the constellations 0.4 and 0.8 cross to locate point (x). Using vector sets AB and BC, the constellations 0.4 and −0.2 cross to locate point (x). Using vector sets AC and BC, the constellations 0.8 and −0.4 cross to locate point (x).
[0018] FIG. 3 shows a point (x) located within three points A, B, and C. A mathematical representation follows:
( AB ) 2 =( Z a ) 2 +( Z a −b ) 2 −2( Z a )( Z a −b )cos(φ AB ) ( AC ) 2 =( Z a ) 2 +( Z a −c ) 2 −2( Z a )( Z a −c )cos(φ AC ) ( BC ) 2 =( Z a −b ) 2 +( Z a −c ) 2 −2( Z a −b )( Z a −c )cos(2π−φ AB −φ AC )
[0019] Where Z a represents the delay from (x) to A, and b and c represent the difference in delay from (x) to B and C with respect to the distance from (x) to A.
[0020] Z a , φ AB , and φ AC are unknowns, they can be found mathematically or by iteration with the three independent equations shown above. With the three variables known, the x and y coordinates of the transmitter (x) can be found.
[0021] FIG. 4 shows a point (x) located outside three points A, B, and C. A mathematical representation follows:
( AB ) 2 =( Z a ) 2 +( Z a −b ) 2 −2( Z a )( Z a −b )cos(φ 1 ) ( AC ) 2 =( Z a ) 2 +( Z a −c ) 2 −2( AC )( Z a −c )cos(φ 2 ) ( BC ) 2 =( Z a −b ) 2 +( Z a −c ) 2 −2( Z a −b )( Z a −c )cos(φ 1 +φ 2 )
[0022] Again, Z a represents the delay from (x) to A, and b and c represent the difference in delay from (x) to B and C with respect to the distance from (x) to A.
[0023] Z a , φ 1 , and φ 2 are unknowns, they can be found mathematically or by iteration with the three independent equations shown above. With the three variables known, the x and y coordinates of the transmitter (x) can be found.
[0024] The remote processing station sends a request to an unknown-location signal receiver, either directly or by way of one of the known-location signal receivers, to send a return signal in order to measure the delay from the unknown-location signal receiver to the processing station.
[0025] The unknown-location signal receiver receives the signals from the three or more unknown-location transmitters and sends the signals from the unknown-location transmitters to the remote processing station.
[0026] The processing station then measures the delay from each of the three or more unknown-location signal transmitters to the processing station, by way of the unknown-location signal receiver and finds the delay from the unknown-location signal transmitters to the unknown-location signal receiver by comparing the signal received by the unknown-location signal receiver and the signal received by any one of the three or more known-location signal receivers and by subtracting the delay from the unknown-location signal receiver to the processing station.
[0027] With each of the points of transmission known, the signal delay from each point of transmission to the unknown-location signal receiver known, standard triangulation methods can be used to find the unknown-location signal receiver.
[0028] In other words, the location of the unknown-location signal receiver is calculated by measuring the difference of reception in time of three or more independent signals to each of the known-location signal receivers and to the unknown-location signal receiver.
[0029] In a second embodiment, the location of the unknown-location transmitters is as described in the first embodiment. A second method of location of the unknown-location receiver is described herein.
[0030] In the second embodiment, the remote processing station sends a request to an unknown-location signal receiver, by way of one or more of the known-location signal receivers, to send a return signal in order to measure the delay from the unknown-location signal receiver to said one or more of the known-location signal receivers in order to measure the delay from the unknown-location signal receiver to the one or more of the known-location signal receivers.
[0031] The unknown-location signal receiver receives the signals from one or more unknown-location transmitters and sends part or all of the signals from the unknown-location transmitters to the remote processing station, by way of the one or more of the known-location signal receivers.
[0032] The processing station then measures the delay from each of the one or more unknown-location signal transmitters to the processing station, by way of the unknown-location signal receiver and finds the delay from the unknown-location signal transmitters to the unknown-location signal receiver by comparing the signal received by the unknown-location signal receiver and the signal received by any one of the three or more known-location signal receivers and by subtracting the delay from the unknown-location signal receiver to the processing station.
[0033] With each of the points of transmission known, the signal delay from each point of transmission to the unknown-location signal receiver known, and the delay from the unknown-location signal receiver to the one or more of the known-location signal receivers known, any combination of the one or more of the known-location signal receivers and the one or more unknown-location signal transmitters is utilized in standard triangulation methods to find the unknown-location signal receiver.
[0034] In a third embodiment, mobile transmitters, such as police band radios are located using a similar method as in the first embodiment. In this method, however, the reception of signals must be time marked as they arrive at the processing station since the location of the transmitter is constantly changing. Location of the unknown-location receiver is as with the first or second method introduced herein.
[0035] In a fourth embodiment, three known-location transceivers, in combination with other unknown-location receivers are used to locate the first unknown-location receiver. Because cellular hand sets, regardless of whether or not in use, are in communication with nearby cell sites, and hand sets within the same cell communicate at different frequencies, each handset in the cell can be used as a repeater.
[0036] FIG. 5 shows three cell towers (T 1 ,T 2 ,T 3 ) and three cellular handsets (H 1 ,H 2 ,H 3 ). The processing station pings each handset in order to find the delay between the handset and the corresponding tower and the delay from each tower to the processing station. If an adjacent handset receives the return signal from its neighboring handset, the delay between the two handsets is used for location. In other words, adjacent handsets are used as repeaters.
[0037] As an example, if H 3 receives the return signal from H 2 , the delay can be found between H 2 and H 3 providing that the communication between each handset and its corresponding tower are at different frequencies, because the processor is aware of when the signal was sent to H 2 and the delays between the handsets and corresponding towers are known. Two possibilities for location of both H 2 and H 3 are indicated. If H 1 is able to receive the return signal from H 2 or H 3 , triangulation to H 2 and H 3 is possible.
[0038] FIG. 6 shows another method wherein a first handset receives signals from two towers and a second handset receives a signal from a third tower. Pinging of the first handset by the corresponding towers reveals two possibilities for location, communication between handsets reveals the true location of both handsets.
[0039] FIG. 7 shows multiple handsets used to indirectly locate a handset, whereby location of the handset to be found can be accomplished by locating other handsets within the cell, an then using the other handsets as known-location transmitters. Although H 5 has no communication with H 1 and H 2 , communication with H 3 and H 4 is possible. With the delays between T 1 and H 1 , T 2 and H 2 , H 1 and H 4 , H 3 and H 5 , T 2 and H 3 , T 2 and H 4 known, H 1 through H 4 can be located and used to find H 5 .
[0040] In the preferred embodiment, the four methods described above are utilized to locate a cell handset. In this embodiment, the remote processor pings three or more cell sites in order to find the delay between the sites and the processing station. Receivers attached to the cell sites scan the area in order to find local transmitters and other handsets. The remote processor then locates the any transmitters by way of the method described in method one herein. The remote processor then pings the cell handset to be located in order to find the delay from the handset to any cell sites in which the handset is communicating. The cell handset, which contains a similar receiver as the cell sites, along with one or more cell sites, is instructed to receive one or more of the transmitters found so that an approximation can be made regarding the location of the handset. Once an approximate location is found, The remote processor then instructs cell sites near the transmitters to accurately locate the located transmitters. The processor also makes an evaluation of transmitter location accuracy based on the distance from the cell sites used to locate the transmitter to the corresponding transmitter and based on how optimum the cell sites are located around the transmitter. Based on this accuracy, the remote processor selects the transmitters which will provide the highest accuracy of handset location. If this selection comprises a nearby cell handset, the nearby handset and any cell towers in communication with the nearby handset are instructed to find the delay from each of the towers in communication with the nearby handset and to use the nearby handset as a signal repeater. If a mobile transmitter is to be utilized, the processor time stamps the delay information to account for a varying location.
[0041] Any combination of location methods described herein are utilized to locate the cell handset. The process continuously repeats to find new, more optimum transmitters. As an example, an emergency vehicle radio would likely become a transmitter as it approaches the handset. | The present invention encompasses a method of location comprising: using a plurality of signal receivers to receive one or more multiple frequency input signals, wherein said multiple frequency input signals are of unknown origin, and said signal receivers are of known physical location, finding a difference in time of the reception of the signals between each of the signal receivers, using the difference in time of reception to locate the origin of the signals, utilizing the signals locate a signal receiver of unknown location. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to the providing of packet data access services in a communication system. Particularly, the invention relates to a method for the routing and control of packet data traffic in a communication system.
[0003] 2. Description of the Related Art
[0004] The amount of packet data traffic continues to increase with the introduction of new multimedia services. It becomes important for packet data access networks to be able to transmit packet data in an efficient and a scalable way that avoids introducing bottlenecks to the architecture of the network. However, simultaneously it must be possible to control the packet data traffic and to apply a variety of policies for the packet data traffic. It must be possible to control the attaching of users to different sub-networks, for instance, in the form of deciding on the providing of addresses from a given access point only to authorized users. The routing and policy control must be efficient irrespective of the type of an access network.
[0005] A problem associated with prior art networks is that the burden of the routing of packet data traffic and the interfacing of external networks for the packet data traffic has been centralized to network elements in the same position in the network topological without taking into consideration the type of packet data traffic or the type of access network used.
[0006] Reference is now made to FIG. 1 , which illustrates a Universal Mobile Telecommunications System (UMTS) and an IP multimedia Subsystem (IMS) in prior art. The IP multimedia architecture for UMTS and GPRS mobile communication networks is referred to as an IP Multimedia Subsystem (IMS). The IMS is defined in the 3G Partnership Project (3GPP) specification 23.228 version 6.14.0, June 2006. The GPRS is defined in the 3GPP specification 23.060, version 6.13.0, June 2006. In FIG. 1 there is shown a mobile station 100 , which communicates with a Radio Network Controller (RNC) 114 within a Radio Access Network 110 . The communication occurs via a Base Transceiver Station (BTS) 112 . The radio access network 110 is, for example, a 2G GSM/EDGE radio access network or a 3G UMTS radio access network. An IP Connectivity Access Network (IP-CAN) functionality connected to access network 110 comprises at least a Serving GPRS Support Node (SGSN) 122 and a Gateway GPRS Support Node (GGSN) 124 . An IP connectivity access network can also been seen as to comprise both a packet switched core network functionality 120 and an access network 110 . The main issue is that an IP-CAN provides IP connectivity to user terminals towards an IP network such as the Internet or an Intranet. SGSN 122 performs all mobility management related tasks and communicates with a Home Subscriber Server (HSS) 160 in order to obtain subscriber information. GGSN 124 provides GPRS access points. There is an access point, for example, to a Media Gateway (MGW) 126 , to a first router 142 attached to an IP network 140 , and to a Proxy Call State Control Function (P-CSCF) 152 . The access point to IP network is used to relay packets to/from an IP network node (IP-N) such as 147 . The packets may be related to, for example, Internet browsing or File Transfer Protocol (FTP) file transfer. The access point for P-CSCF 152 is used to convey signaling traffic pertaining to IP multimedia. GGSN 124 establishes Packet Data Protocol (PDP) contexts, which are control records associated with a mobile subscriber such as mobile station 100 . A PDP context provides an IP address for packets received from or sent to mobile station 100 . A PDP context has also associated with it a UMTS bearer providing a certain QoS for mobile station 100 . In GGSN 124 there is a primary PDP context for the signaling packets associated mobile station 100 . For the user plane data packets carrying at least one IP flow there is established at least one secondary PDP context. The at least one IP flow is established between a calling terminal and a called terminal in association with an IP multimedia session. An IP flow carries a multimedia component, in other words a media stream, such as a voice or a video stream in one direction. For voice calls at least two IP flows are required, one for the direction from the calling terminal to the called terminal and one for the reverse direction. In this case an IP flow is defined as a quintuple consisting of a source port, a source address, a destination address, a destination port and a protocol identifier.
[0007] The communication system illustrated in FIG. 1 comprises also the IP Multimedia Subsystem (IMS) functionality. The IMS is used to set-up multimedia sessions over IP-CAN. The network elements supporting IMS comprise at least one Proxy Call State Control Function (P-CSCF), at least one Inquiring Call State Control Function (I-CSCF), at least one Serving Call State Control Function S-CSCF, at least one Brakeout Gateway Control Function (BGCF) and at least one Media Gateway Control Function (MGCF). As part of the IMS there is also at least one Home Subscriber Server (HSS). Optionally, there is also at least one Application Server, which provides a variety of value-added services for mobile subscribers served by the IP multimedia subsystem (IMS).
[0008] P-CSCF 152 receives signaling plane packets from GGSN 124 . Session Initiation Protocol (SIP) signaling messages are carried in the signaling plane packets. The signaling message is processed by P-CSCF 152 , which determines the correct serving network for the mobile station 100 that sent the signaling packet. The determination of the correct serving network is based on a home domain name provided from mobile station 100 . Based on the home domain name is determined the correct I-CSCF, which in FIG. 1 is I-CSCF 154 . I-CSCF 154 hides the topology of the serving network from the networks, in which mobile station 100 happens to be roaming. I-CSCF 154 takes contact to home subscriber server 160 , which returns the name of the S-CSCF, which is used to determine the address of S-CSCF 156 to which the mobile station 100 is to be registered. If I-CSCF 156 must select a new S-CSCF for mobile station 100 , home subscriber server 160 returns required S-CSCF capabilities for S-CSCF selection.
[0009] Upon receiving a registration, S-CSCF 156 obtains information pertaining to the profile of the mobile station 100 from HSS 160 . The information returned from HSS 160 may be used to determine the required trigger information that is used as criterion for notifying an application server 162 . The trigger criteria are also referred to as filtering criteria. Application server 162 may be notified on events relating to incoming registrations or incoming session initiations. Application server 162 communicates with S-CSCF 156 using the ISC-interface. The acronym ISC stands for IP multimedia subsystem Service Control interface. The protocol used on ISC interface is SIP. AS 162 may alter SIP INVITE message contents that it receives from S-CSCF 156 . The modified SIP INVITE message is returned back to S-CSCF 156 .
[0010] If the session to be initiated is targeted to a PSTN subscriber or a circuit switched network subscriber, the SIP INVITE message is forwarded to a BGCF 158 . BGCF 158 determines the network in which interworking to PSTN or the circuit switched network should be performed. In case PSTN interworking is to be performed in the current network, the SIP INVITE message is forwarded to MGCF 159 from BGCF 158 . In case PSTN interworking is to be performed in another network, the SIP INVITE message is forwarded from BGCF 158 to a BGCF in that network (not shown). MGCF 159 communicates with MGW 126 . The user plane packets carrying a media bearer or a number of interrelated media bearers for the session are routed from GGSN 124 to MGW 126 as illustrated in FIG. 1 .
[0011] If the session to be initiated is targeted to a terminal 146 , which is a pure IP terminal, S-CSCF 156 forwards the SIP INVITE message to terminal 146 . Terminal 146 communicates with a second router 144 , which interfaces IP network 140 . IP network 140 is used to carry the user plane IP flows associated with the session established between mobile station 100 and terminal 146 . The user plane IP flows between first router 142 and GGSN 124 are illustrated with line 128 . The user plane IP flows between second router 144 and terminal 146 are illustrated with line 148 .
[0012] Generally, in FIG. 1 user plane is illustrated with a thick line and control plane with thinner line.
[0013] One problem in the architecture illustrated in FIG. 1 is, for example, that if there are other types of IP-CANs (not shown) that are used to access IMS 150 or the amount of user plane traffic grows by way of a myriad of IP multimedia sessions specifically GGSN 124 may be required to process significant packet data traffic. Therefore, it would be beneficial to have an architecture, which may provide for access point gateway functionality at different points in the network topology and avoids the buildup of network bottlenecks.
SUMMARY OF THE INVENTION
[0014] The invention relates to a method comprising: initiating the establishment of a security association between a client node and a first gateway node; obtaining at least one user identity and user authentication data from an authentication server; authenticating the user with the authentication data; providing said at least one user identity to a second gateway node; obtaining for the user authorization pertaining to at least one access point in said second gateway node; providing said authorization pertaining to said at least one access point and an address for said client node to said first gateway node; providing said address to said client node from said first gateway node; transmitting a packet from said client node to said first gateway node, said packet comprising said address as source address; allowing said packet based on said authorization pertaining to said at least one access point; and routing said packet to a destination node in said first gateway node based on at least said address.
[0015] The invention relates also to a method comprising: initiating the establishment of a security association between a client node and a first gateway node; obtaining at least one user identity and user authentication data from an authentication server; authenticating the user with the authentication data; providing said at least one user identity to a control node; obtaining for the user authorization pertaining to at least one access point to said first gateway node from said control node; obtaining an address for said client node in said first gateway node; providing said address to said client node from said first gateway node; transmitting a packet from said client node to said first gateway node, said packet comprising said address as source address; allowing said packet based on said authorization pertaining to said at least one access point; and routing said packet to a destination node in said first gateway node based on at least said address.
[0016] The invention relates also to a method comprising: initiating the establishment of a security association between a client node and a first gateway node; obtaining at least one user identity and user authentication data from an authentication server; authenticating the user with the authentication data; requesting the creation of a packet data protocol context from a second gateway node; creating a packet data protocol context in said second gateway node; determining session control node information in said second gateway node; providing said session control node information in at least one protocol configuration option to said first gateway node; providing said session control node information to said client node in a configuration payload of a security association related message.
[0017] The invention relates also to a communication system, comprising: a client node configured to initiate the establishment of a security association with a first gateway node, to transmit a packet to said first gateway node, said packet comprising an address as source address; a first gateway node configured to establish a security association with said client node, to obtain at least one user identity and user authentication data from an authentication server, to authenticate the user with the authentication data, to providing said at least one user identity to a second gateway node, to provide said address to said client node from said first gateway node, to receive said packet comprising said address as source address, to allow said packet based on said authorization pertaining to said at least one access point and to route said packet to a destination node based on at least said address; and a second gateway node configured to obtain for the user an authorization pertaining to at least one access point and to provide said authorization pertaining to said at least one access point and an address for said client node to said first gateway node.
[0018] The invention relates also to a communication system comprising: a client node configured to initiate the establishment of a security association towards a first gateway node; and a first gateway node configured to obtaining at least one user identity and user authentication data from an authentication server, to authenticate the user with the authentication data, to provide said at least one user identity to a control node, to obtain for the user authorization pertaining to at least one access point, to obtain an address for said client node, to providing said address to said client node, to receive a packet from said client node, said packet comprising said address as source address, to allowing said packet based on said authorization pertaining to said at least one access point and to route said packet to a destination node in said first gateway node based on at least said address.
[0019] The invention relates also to a communication system, comprising: a client node configured to initiate the establishment of a security association to a first gateway node; said first gateway node configured to obtain at least one user identity and user authentication data from an authentication server, to request the creation of a packet data protocol context from a second gateway node, to authenticate the user with the authentication data and to providing said session control node information to said client node in a configuration payload of a security association related message; and said second gateway node configured to create a packet data protocol context in said second gateway node, to determine session control node information in said second gateway node, to providing said session control node information in at least one protocol configuration option to said first gateway node.
[0020] The invention relates also to a network node, comprising: a security entity configured to establish a security association with a client node, to obtain at least one user identity and user authentication data from an authentication server, to authenticate the user with the authentication data, to providing said at least one user identity to a gateway node, to provide an address to said client node; a communication entity configured to receive said packet comprising said address as source address; a filtering entity configured to allow said packet based on said authorization pertaining to said at least one access point; and a router entity configured to route said packet to a destination node based on at least said address.
[0021] The invention relates also to a network node, comprising: means for establishing a security association with a client node; means for obtaining at least one user identity and user authentication data from an authentication server; means for authenticating the user with the authentication data; means for providing said at least one user identity to a gateway node; means for to providing an address to said client node; means for receiving a packet comprising said address as source address; means for allowing said packet based on said authorization pertaining to said at least one access point; and means for routing said packet to a destination node based on at least said address.
[0022] The invention relates also to a network node, comprising: a security entity configured to obtain at least one user identity and user authentication data from an authentication server, to authenticate the user with the authentication data, to provide said at least one user identity to a control node, to obtain for the user authorization pertaining to at least one access point, to obtain an address for said client node, to providing said address to said client node; a communication entity configured to receive a packet from said client node, said packet comprising said address as source address; a filtering entity configured to allow said packet based on said authorization pertaining to said at least one access point; and a routing entity configured to route said packet to a destination node based on at least said address.
[0023] The invention relates also to a network node, comprising: means for obtaining at least one user identity and user authentication data from an authentication server; means for authenticating the user with the authentication data; means for providing said at least one user identity to a control node; means for obtaining for the user authorization pertaining to at least one access point; means for obtaining an address for said client node; means for providing said address to said client node; means for receiving a packet from said client node, said packet comprising said address as source address; means for allowing said packet based on said authorization pertaining to said at least one access point; and means for routing said packet to a destination node based on at least said address.
[0024] The invention relates also to a network node, comprising: a security entity configured to establish a security association with a client node, to obtain at least one user identity and user authentication data from an authentication server, to request the creation of a packet data protocol context from a second gateway node, to authenticate the user with the authentication data and to providing said session control node information to said client node in a configuration payload of a security association related message.
[0025] The invention relates also to a network node, comprising: means for establishing a security association with a client node; means for obtaining at least one user identity and user authentication data from an authentication server; means for requesting the creation of a packet data protocol context from a second gateway node; means for authenticating the user with the authentication data; and means for providing said session control node information to said client node in a configuration payload of a security association related message.
[0026] The invention relates also to a computer program embodied on a computer readable medium, when executed on a data-processing system, the computer program being configured to perform: establishing a security association with a client node; obtaining at least one user identity and user authentication data from a server; authenticating the user with the authentication data; providing said at least one user identity to a gateway node; providing an address to said client node; receiving a packet comprising said address as source address; allowing said packet based on said authorization pertaining to said at least one access point; and routing said packet to a destination node based on at least said address.
[0027] The invention relates also to a computer program embodied on a computer readable medium, when executed on a data-processing system, the computer program being configured to perform: obtaining at least one user identity and user authentication data from an authentication server; authenticating the user with the authentication data; providing said at least one user identity to a control node; obtaining for the user authorization pertaining to at least one access point; obtaining an address for said client node; providing said address to said client node; receiving a packet from said client node, said packet comprising said address as source address; allowing said packet based on said authorization pertaining to said at least one access point; and routing said packet to a destination node based on at least said address.
[0028] The invention relates also to a computer program embodied on a computer readable medium, when executed on a data-processing system, the computer program being configured to perform: establishing a security association with a client node; obtaining at least one user identity and user authentication data from an authentication server; requesting the creation of a packet data protocol context from a second gateway node; authenticating the user with the authentication data; and providing said session control node information to said client node in a configuration payload of a security association related message.
[0029] In one embodiment of the invention, the communication system further comprises a communication entity in the second gateway node, which is configured to provide said at least one user identity to a control node. The control node, in other words, a control server, is, for example, an IP Multimedia Register (IMR), a Remote Authentication Dial In User Service (RADIUS) server, a Lightweight Directory Access Protocol (LDAP) database server or an Online Charging Server (OCS). A database entity in the control node is configured to determine said authorization pertaining to said at least one access point node with said at least one user identity. The communication entity in the control node is configured to indicate said authorization to said second gateway node.
[0030] In one embodiment of the invention, a session signaling entity in the client node is configured to add a session signaling message pertaining to a session to said packet. A session control node is configured to provide an indication of said session to the control node, which supervises, for example, user specific prepaid accounts. The control node configured to detect a session release condition for said session and to send a release request message to said first gateway node. The security entity in the first gateway node configured to delete a second security association.
[0031] In one embodiment of the invention, the second gateway node is a Gateway General Packet Radio Service Support Node.
[0032] In one embodiment of the invention, the user is a mobile subscriber, which is identified to the client node using a subscriber identity module or any other card.
[0033] In one embodiment of the invention, the first gateway node comprises a Virtual Private Network (VPN) gateway. In one embodiment of the invention, the first gateway node comprises a Serving GPRS Support Node.
[0034] In one embodiment of the invention, the communication system comprises an Internet Protocol Connectivity Access Network (IP-CAN) and a proxy network node with an application entity configured to receive signaling messages from a terminal via said Internet Protocol Connectivity Access Network (IP-CAN). The application entity may comprise Session Initiation Protocol (SIP) functionality. The proxy network node may be, for example, a Proxy CSCF (P-CSCF).
[0035] In one embodiment of the invention, the Internet Protocol Connectivity Access Network comprises a Serving General Packet Radio Service Support Node and a Gateway General Packet Radio Service Support Node. The first gateway node may be a Serving GPRS Support Node, which is configured to a communication entity that allows the first gateway node to communication towards a control node via the Radius protocol or the Diameter protocol. The second gateway may be a Gateway GPRS Support Node.
[0036] In one embodiment of the invention, the signaling messages comprise Session Initiation Protocol (SIP) session invitation messages.
[0037] In one embodiment of the invention, said communication system comprises a mobile communication network. In one embodiment of the invention, said terminal comprises a mobile station or generally a mobile terminal. In one embodiment of the invention a user of a mobile terminal is identified using a subscriber module, for example, User Services Identity Module (UMTS) or a Subscriber Identity Module (SIM). The combination of Mobile Equipment (ME) and a subscriber module may be referred to as a mobile subscriber.
[0038] In one embodiment of the invention, the communication system comprises at least one of a Global System of Mobile Communications (GSM) network and a Universal Mobile Telephone System (UMTS) network. The mobile station may be, for example, a GSM mobile station or a UMTS mobile station with a dual mode or multimode functionality to support different access types.
[0039] In one embodiment of the invention, the computer program is stored on a computer readable medium. The computer readable medium may be a removable memory card, a removable memory module, a magnetic disk, an optical disk, a holographic memory or a magnetic tape. A removable memory module may be, for example, a USB memory stick, a PCMCIA card or a smart memory card.
[0040] The embodiments of the invention described hereinbefore may be used in any combination with each other. Several of the embodiments may be combined together to form a further embodiment of the invention. A method, a communication system, a network node or a computer program to which the invention is related may comprise at least one of the embodiments of the invention described hereinbefore.
[0041] The benefits of the invention are related to the increased scalability. Packet data traffic may be distributed more evenly in different points within the network topology.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] The accompanying drawings, which are included to provide a further understanding of the invention and constitute a part of this specification, illustrate embodiments of the invention and together with the description help to explain the principles of the invention. In the drawings:
[0043] FIG. 1 is a block diagram illustrating a Universal Mobile Telecommunications System (UMTS) and an IP multimedia Subsystem (IMS) in prior art;
[0044] FIG. 2 is a block diagram illustrating a communication system with two gateway nodes in one embodiment of the invention;
[0045] FIG. 3 is a block diagram illustrating a single gateway node communication system in one embodiment of the invention;
[0046] FIG. 4 is a block diagram illustrating the distribution of session control node information in one embodiment of the invention;
[0047] FIG. 5A is a flow chart illustrating a first part of a method for the transmitting of signaling plane information in one embodiment of the invention;
[0048] FIG. 5B is a flow chart illustrating a second part of a method for the transmitting of signaling plane information in one embodiment of the invention; and
[0049] FIG. 6 is a block diagram illustrating a network node in one embodiment of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0050] Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
[0051] FIG. 2 is a block diagram illustrating a communication system with two gateway nodes in one embodiment of the invention.
[0052] In FIG. 2 there is a client node 250 . It communicates with an IP access network 252 . The IP access network may be any wired or wireless network. In FIG. 2 there is also a Virtual Private Network gateway VPN-GW 268 . VPN-GW 268 provides IP Security (IP-SEC) security associations for client nodes such as client node 250 . The security associations are provided over IP access net-work 252 . In FIG. 2 there are two authentication authorization and accounting servers, namely AAAv 262 and AAAh 264 . AAAv 262 acts as the AAA server within the network of VPN-GW 268 , whereas AAAh 264 acts as the AAA server within the home network of the mobile subscriber associated with client node 250 . VPN-GW 268 communicates with AAAv 262 using either the Radius protocol or the Diameter protocol. Similarly, AAAv 262 communicates with AAAh 264 using the Radius or the Diameter protocol. There is also an interface from AAAh 264 to the Home Subscriber Server (HSS) of the mobile sub-scriber. In FIG. 2 there is also an IP multimedia subsystem 270 . There is a Proxy Call State Control Function (P-CSCF) 274 and a media gateway 276 in IP multimedia subsystem (IMS) 270 . There is also a home subscriber server 272 within IMS 270 . HSS 272 is configured to communicate with AAAh 264 . There is also a Control Server (CTRL) 278 . Control server 278 may be, for example, an LDAP server storing a directory database, an Online Charging Server (OCS) or an IP Multimedia Register (IMR). Control server 278 is, for example, in charge of providing user data and user service subscription information. Mobile subscriber subscription information indicates, for example, information on access point names that are allowed for specified mobile subscribers. The subscriber information also indicates what subnetworks are allowed as destination networks for specified subscribers and what quality of service may be provided for the packet traffic pertaining to the specified subscribers. There may also be information on pre-paid accounts associated with the mobile subscriber. Control server 278 may also be a session information repository. In one embodiment of the invention, the control server is merely a software component or a separate computer plug-in unit directly comprised in a GGSN 266 or a similar gateway node. There is also a sub-network 280 which comprises a server 282 . In FIG. 2 there is also a second sub network 140 , which comprises a node 147 and an ingress router 142 and an egress router 144 . There is also a second terminal 146 which is configured to communicate with sub-network 140 via user plane connection 148 . In FIG. 2 there is also gateway GPRS support node GGSN 266 .
[0053] At time T 1 client node 250 wishes to establish an IPSEC security association towards VPN-GW 268 . The security association initiation is performed, for example, with Internet Key Exchange (IKE) IKEv2 protocol defined in Internet Engineering Task Force (IETF) document 4306, December, 2005. It should be noted that other versions of IKE, may as well be used for the purposes of the disclosed method. Also other key exchange protocols may be used for the establishing of security associations or secure tunnels.
[0054] The security association initiation phase, called IKE_SA_INIT in IKEv2, between client node 250 and VPN-GW 268 is illustrated with double-headed arrow 201 . Thereupon, the IKEv2 authentication phase, called IKE_AUTH in IKEv2, is commenced. The IKEv2 authentication phase is illustrated with double-headed arrow 202 . First, client node 250 sends an IKEv2 authentication message to VPN-GW 268 . The authentication message does not have an IKEv2 AUTH payload, which indicates the desire of client node 250 to use extensible authentication, for example, the Encapsulated Authentication Protocol (EAP), which is defined, for example, in the IETF RFC 4187. The IKEv2 authentication message provides the identity of the current user of client node 250 and the name of the access point desired by the user. The identity of the user is expressed as a Network Access Identifier (NAI). The user may, for example, be identified within NAI using a logical name such as the ones used in E-mail address username parts or an MSISDN number. Upon obtaining the NAI in VPN-GW 268 , the NAI is provided by VPN-GW 268 to AAAh 264 via AAAv 262 . This message chain is not shown in FIG. 2 . The correct AAAh is found using the mobile country code and mobile network code provided as part of the NAI. On the basis of the user identity in NAI, AAAh 264 obtains authentication information from HSS 272 , as illustrated with arrow 203 . AAAh 264 may also obtain from HSS 272 other data for the user, which comprises, for example, an IMSI and an MSISDN. The user identities IMSI and MSISDN may be referred to as user data hereinafter. User data and authentication information is provided from AAAh 264 to AAAv 262 , as illustrated with arrow 204 . The user data and authentication information are further provided from AAAv 262 to VPN-GW 268 , as illustrated with arrow 205 . As part of ongoing IKEv2 authentication phase (IKE_AUTH) and the message exchange associated therewith, which illustrated with double-headed arrow 202 , VPN-GW 268 sends to client node 250 an IKEv2 authentication message. The IKEv2 authentication message has encapsulated within it an Encapsulated Authentication Protocol (EAP) authentication request message pertaining to, for example, EAP-SIM or EAP-AKA authentication methods. The EAP authentication request message comprises, for example, a random challenge (RAND) and may also comprise a network authentication token (AUTN) and a Message Authentication Code (MAC). In order to obtain successful authentication, client node 250 sends a proper response parameter (RES), calculated in client node 250 on the basis of information in the EAP authentication request, to VPN-GW 268 in an EAP authentication response message further encapsulated in an IKE_AUTH message, which is, once again part of message exchange illustrated with double-headed arrow 202 . Upon receiving the EAP authentication request message, VPN-GW 268 checks at least the given RES and finds it correct. Because the RES was correct, WPN-GW 268 sends an EAP success message encapsulated in an IKE_AUTH message to client node 250 . This message is also part of the message exchange illustrated with double headed arrow 202 .
[0055] At this point a PDP context is not opened in GGSN 266 . VPN-GW 268 sends a first authorization message comprising the user identities IMSI and MSISDN and the requested APN to GGSN 266 , as illustrated with arrow 206 . The first authorization request message may be sent, for example, using the GPRS Tunneling Protocol (GTP-C), the Radius protocol or the Diameter protocol. GGSN 266 sends a second authorization request message to control server 278 as illustrated with arrow 207 . The second authorization request message comprises the IMSI and MSISDN and the desired APN. Control server 278 checks from its database the authorization of the user to use the APN requested. If there is an authorization, control server 278 sends an authorization accepted message to GGSN 266 , as illustrated with arrow 208 . GGSN 266 allocates an IP address from the APN. The IP address allocation may also be performed by control server 278 or the address may already have been provided in message 208 to GGSN 266 . GGSN 266 sends the IP address to VPN-GW 268 , as illustrated with arrow 209 . The IP address is further provided from VPN-GW 268 to client node 250 , as illustrated with arrow 210 .
[0056] In one embodiment of the invention, the providing of the IP address to client node 250 is performed in an earlier phase when the authentication is still ongoing. The IP address may be provided in association with an extra IKE_AUTH message exchange between client 250 and VPN-GW 268 .
[0057] At time T 2 , client node 250 starts using the IP address obtained. Thereupon, client node 250 sends a session related packet to VPN-GW 268 . Upon receiving the packet VPN-GW 268 checks from its firewall rules whether the access point for the source IP address is allowed to communicate with the destination IP address indicated in the packet. If the firewall rules allow the packet, the packet is routed towards the destination by VPN-GW 268 . In FIG. 2 there are shown four routes for packet traffic, namely route R 1 towards sub-network 140 , route R 2 towards sub-network 280 , route R 3 towards P-CSCF 274 and route R 4 towards MGW 276 . Based on routing rules, VPN-GW 268 sends the session signaling related packet over route R 3 to P-CSCF 274 . At some point in session signaling P-CSCF 274 sends a response signaling message comprised in a packet towards client node 250 . The response packet is processed in VPN-GW 268 so that is it subjected to firewall rule checking and routing process in a manner similar to packet sent by client node 250 . Finally the packet is assumed to be received to client node 250 . At a later time, a multimedia session is assumed to be established from client node 250 via VPN-GW 268 to a destination node, for example, network node 146 . The user plane for the session uses an IPSEC security association between client node 250 and VPN-GW 268 . The IP multimedia session goes on for a certain time. At time T 3 control server 278 detects that the prepaid account associated with the mobile subscriber for client node 250 has been exhausted. Therefore, control server 278 sends a session release request message GGSN 266 , as illustrated with arrow 211 . The session release request message is sent further by GGSN 266 to VPN-GW 268 , as illustrated with arrow 212 . In response to the release request VPN-GW 268 deletes the security association used by the ongoing IP multimedia session. Preferably, the user plane security association is deleted.
[0058] FIG. 3 is a block diagram illustrating a single gateway node communication system in one embodiment of the invention.
[0059] In FIG. 3 there is no GGSN but all policy signaling is relayed via VPN-GW 268 and control server 278 . At time T 1 client node 250 initiates the establishing of a security association towards VPN-GW 268 . The security association initiation (IKE_SA_INIT) is illustrated with double-headed arrow 301 . Thereupon, the IKEv2 authentication phase (IKE_AUTH) is commenced. Client node 250 sends an IKEv2 authentication message to VPN-GW 268 , as part of authentication phase messaging illustrated with double-headed arrow 302 . The IKEv2 authentication message provides the identity of the current user of client node 250 and the name of the access point desired by the user. The identity of the user is expressed as a Network Access Identifier (NAI). Upon obtaining the NAI in VPN-GW 268 , the NAI is provided by VPN-GW 268 to AAAh 264 via AAAv 262 (not shown). The correct AAAh is found using the mobile country code and mobile network code provided as part of the NAI. On the basis of the user identity in NAI, AAAh 264 obtains authentication information from HSS 272 , as illustrated with arrow 303 . The authentication information may comprise a number of GSM authentication triplets or a number of UMTS AKA authentication vectors. AAAh 264 may also obtain from HSS 272 other data for the user, which comprises, for example, an IMSI and an MSISDN. The user identities IMSI and MSISDN may be referred to as user data hereinafter. User data and authentication information is provided from AAAh 264 to AAAV 262 , as illustrated with arrow 304 . The user data and authentication information are further provided from AAAv 262 to VPN-GW 268 , as illustrated with arrow 305 . Thereupon, the authentication is performed between client node 250 and VPN-GW 268 . The continued authentication procedure between VPN-GW 268 and client node 250 is comprised in the messaging illustrated with double-headed arrow 302 . The authentication procedure uses IKEv2 authentication phase (IKE_AUTH) messages, which have encapsulated in them Encapsulated Authentication Protocol (EAP) message pertaining to, for example, EAP-SIM or EAP-AKA authentication methods. The EAP challenge and response authentication procedures are performed. Successful authentication of client node 250 is followed by and EAP success message from VPN-GW 268 to client node 250 .
[0060] Thereupon, VPN-GW 268 sends an authorization request message to control server 278 as illustrated with arrow 306 . The authorization request message comprises APN desired by client node 250 and user data identifying the user of client node 250 , for example the IMSI or the MSISDN of the user. If the user is authorized to use the APN, control server 278 sends an authorization accept message VPN-GW 268 as illustrated with arrow 307 . The IP address for client node 250 may be obtained from control server 278 or from another node interfaced by VPN-GW 268 . Anyway, the IP address allocated from the access point identified by the APN is provided from VPN-GW 268 to client node 250 , as illustrated with arrow 308 . The message 308 may be comprised in the IKEv2 authentication phase.
[0061] In one embodiment of the invention, the IP address may also be provided in an informational IKEv2 message only after complete IKEv2 authentication phase. In one embodiment of the invention, the sending of authorization request to control server 278 may be sent during authentication messaging process illustrated with double-headed arrow 305 .
[0062] At time T 2 client node 250 starts establishing an IP multimedia session towards destination terminal. The IP multimedia session is established via for example session initiation protocol signaling, which is conveyed via VPN-GW 268 to P-CSCF 274 and from there onwards to other call state control functions that are not shown. The IP multimedia session is assumed to reach a two-way communication state, for example, a speed state. The IP multimedia session is also made known control server 278 (messaging not shown).
[0063] At time T 3 , the prepaid account for the use of client node 250 is exhausted and therefore control server 278 sends a session release request message to VPN-GW 268 as illustrated with arrow 309 . In response to the session release request VPN-GW 268 deletes the security association carrying at least the user plane packets for the IP multimedia session. In one embodiment of the invention all security associations established between client node 250 VPN-GW 268 are deleted.
[0064] FIG. 4 is a block diagram illustrating the distribution of session control node information in one embodiment of the invention.
[0065] In FIG. 4 there is a VPN-GW 268 which communicates with a GGSN 266 . There is also transmitted user plane packet traffic between VPN-GW 268 and GGSN 266 . In FIG. 4 GGSN 266 is used to provide the P-CSCF address for P-CSCF 274 to client node 250 . At time T 1 client node 250 wishes to establish an IPSEC security association between client node 250 and VPN-GW 268 . VPN-GW 268 authenticates client node 250 in a manner similar to FIGS. 2 and 3 . The initiation of security association establishment between client node 250 and VPN-GW 268 is illustrated with double-headed arrow 401 . The IKEv2 authentication phase is started, as illustrated with double-headed arrow 402 . Client node 250 provides user identity for it's user to VPN-GW 268 . A NAI is sent from VPN-GW 268 to AAAh 264 via AAAv 262 . The authentication information and user identity information from HSS 272 are provided back to VPN-GW 268 via the reverse path, as illustrated with arrows 403 , 404 and 405 . EAP authentication challenge and response messaging is performed over between client node 250 and VPN-GW 268 as part of IKEv2 authentication phase.
[0066] Thereupon, VPN-GW 268 starts PDP context establishment to GGSN 266 , as illustrated with arrow 406 . Beforehand GGSN 266 has been configured with configuration information comprising, for example, the address for P-CSCF 274 . As the create PDP context request message 406 arrives at GGSN 266 , it is responded by GGSN 266 with create PDP context request accept message, as illustrated with arrow 407 . To the create PDP context request accept message or any other GTP-C protocol message GGSN 266 adds a protocol configuration option, which comprises the P-CSCF address. As the create PDP context request accept message is received in VPN-GW 268 , the P-CSCF address and other similar configuration option fields are extracted by VPN-GW 268 . VPN-GW 268 provides the IP address to client node 250 in an IKEv2 authentication related message illustrated with arrow 408 , to which it adds a configuration payload, which further comprises the P-CSCF address. Thereupon, client node 250 may start establishing a SIP session via P-CSCF 274 further towards IP multimedia subsystem 270 .
[0067] FIG. 5A is a flow chart illustrating a first part of a method for the transmitting of signaling plane information in one embodiment of the invention.
[0068] At step 500 , an association establishment is started between a client node and a first network node. In one embodiment of the invention the first network node is a virtual private network gateway comprising firewall functionality and a router functionality.
[0069] At step 502 , authentication data is obtained to the first network node from an authentication server using an identity provided by the client node at step 500 . In one embodiment of the invention the authentication server is an authentication authorization and accounting server that is an AAA server. An AAA server may contact another AAA server in the client's home network. An AAA server may obtain authentication information from an external source such as an authentication center within a GSM network. User identity and user data is obtained to the first network node from the authentication server. The user identity may comprise, for example, an IMSI or an MSISDN. The user data may comprise an access point name provided from the client node.
[0070] At step 504 , the client node authentication is continued.
[0071] At step 506 , the user identity and user data is provided from the first network node to the second network node. In one embodiment of the invention, the second network node is a GGSN.
[0072] At the step 508 , the user is authorized in the second network node. In one embodiment of the invention, the authorization comprises the user's right to obtain an IP address from a certain access point. In one embodiment of the invention, the authorization is checked from a further third network node, which is, for example, an LDAP directory server, a Radius server or an IP multimedia register comprising user authorization information pertaining to different services and access points.
[0073] At the step 510 , an address is provided from the second network node to the client node. In one embodiment of the invention, the address is an IP address. In one embodiment of the invention the IP address is provided in an IKE version 2 informational message in a configuration payload parameter. In one embodiment of the invention, the IP address is provided in an IKEv2 authentication message.
[0074] At the step 512 , the client node sends a signaling packet toward a session control node. In one embodiment of the invention the signaling packet is an IP packet comprising a session initiation protocol message. The session control node may for example a proxy call state control function pertaining to IP multimedia subsystem.
[0075] At the step 514 , the first network node performs firewall filtering and packet routing for the aforementioned packet.
[0076] At the step 516 , the session control node provides a response signaling to the client node. The method continues at the step 518 also labeled with letter A.
[0077] FIG. 5B is a flow chart illustrating a second part of a method for the transmitting of signaling plane information in one embodiment of the invention.
[0078] At the step 518 , a second network node detects a session release condition. The session release condition may have been indicated from the third network node. The third network node for example supervises prepaid account exhaustion.
[0079] At the step 520 , the second network node requests session release form the first network node.
[0080] At the step 522 , the first network node requests secure association deletion from the client node. In one embodiment of the invention the security association carries the user plane packets pertaining to the multimedia session to be released.
[0081] FIG. 6 is a block diagram illustrating a network node in one embodiment of the invention. The network node acts as, for example, a VPN gateway as illustrated in FIGS. 2 , 3 and 4 .
[0082] In FIG. 6 there is illustrated a network node 600 . Network node 600 comprises at least one processor, for example, processor 610 , at least one secondary memory, for example secondary memory 620 and at least one primary memory, for example, primary memory 630 . Network node 600 may also comprise any number of other processors and any number secondary memory units. There may also be other primary memories with separate address spaces. Network node 600 comprises also a network interface 640 . The network interface may, for example, be a cellular radio interface, a Wireless Local Area Network (WLAN) interface, a local area network interface or a wide area network interface. The network interface is used to communicate to the Internet or locally to at least one computer.
[0083] Processor 610 or at least one similarly configured processor within network node 600 executes a number of software entities stored at least partly in primary memory 630 . Primary memory 630 comprises a communication entity 632 , a filtering entity 634 , a routing entity 636 and an authentication entity 638 . Communication entity 632 communicates with remote network nodes for enabling them to communicate with other entities within network node 600 . Communication entity 632 comprises, for example, the Internet Protocol (IP) protocol stack, the IP stack together with the Diameter protocol, the Radius protocol or any successor protocol thereof. Authentication entity 638 communicates with an authentication server via communication entity 632 . Authentication entity may authenticate a client node, for example, using the IKEv2 protocol and at least one EAP authentication method such as EAP-SIM or EAP-AKA. Filtering entity 634 takes care of packet filtering and passing functions according to filtering rules. The filtering rules may be stored to secondary memory 620 . The filtering rules may be updated based on information obtained from communication entity 632 .
[0084] The entities within network node 600 such as communication entity 632 , filtering entity 634 , routing entity 636 and authentication entity 638 may be implemented in a variety of ways. They may be implemented as processes executed under the native operating system of the network node or the network node. The entities may be implemented as separate processes or threads or so that a number of different entities are implemented by means of one process or thread. A process or a thread may be the instance of a program block comprising a number of routines, that is, for example, procedures and functions. The entities may be implemented as separate computer programs or as a single computer program comprising several modules, libraries, routines or functions implementing the entities. The program blocks are stored on at least one computer readable medium such as, for example, a memory circuit, a memory card, a holographic memory, magnetic or optic disk. Some entities may be implemented as program modules linked to another entity. The entities in FIG. 6 may also be stored in separate memories and executed by separate processors, which communicate, for example, via a message bus or an internal network within the network node. An example of such a message bus is the Peripheral Component Interconnect (PCI) bus. The internal network may be, for example, a local area network. The entities may also be partly or entirely implemented as hardware, such as ASICS or FPGAs. An entity may be a software component or a combination of software components.
[0085] It is obvious to a person skilled in the art that with the advancement of technology, the basic idea of the invention may be implemented in various ways. The invention and its embodiments are thus not limited to the examples described above; instead they may vary within the scope of the claims. | The invention relates to a method, which comprising initiating the establishment of a security association between a client node and a gateway node. User data is obtained from an authentication server and the user is au-thenticated. Authorization is obtained for the user for certain network services from a separate authorization node. An authorized address is provided to the client node. The authorization is checked by the gateway node for the allowing outbound packets to specific destinations. | 7 |
[0001] This application claims the benefit of provisional application 62/119,095
BACKGROUND OF THE INVENTION
[0002] This invention relates to an assembly for a case seat which is configured to attach to the outer surface of a small case containing items such as eyeglasses, a cellphone, or other similar small items.
[0003] When driving a car, it is sometimes necessary to wear sunglasses to protect eyes from bright sunlight exposure. When sunglasses are not in use while driving, they need to be in a safe and accessible place. A conventional eyeglass case or small case cannot be attached to a single place. Additionally, having an easily accessible stand for a cell phone is also desirably. The present invention provides an improved case seat that easily transitions between a fastener to secure a case in place into a stand that allows the case to be suspended in an upright position.
SUMMARY OF THE INVENTION
[0004] One object of this invention is to provide for a case seat assembly that attaches to the outer surface of a small storage container containing eyeglasses, a cellphone or other small items. The case seat has a base with a coupling portion that has a face which is attached abutting the surface of the storage container. The opposite side of the coupling portion has a mating attaching element which removably connects to a female attaching element encompassed within a housing which is rotatably mounted to one side of a clamp fastener. In use the clamp has a fastener that detaches from the coupling portion and attaches to a belt, sun visor, purse, bag or other type of item. The backside of the clamp fastener has a recessed portion that receives a kickstand for holding the storage container in an upright position.
DESCRIPTION OF DRAWINGS
[0005] FIG. 1 is an exploded view of one embodiment of the case seat assembly.
[0006] FIG. 2 is a front view of one embodiment the case seat assembly.
[0007] FIG. 3 is a side view of one embodiment case seat assembly with glass case attached and kickstand
[0008] FIG. 4 is side view of one embodiment case assembly with glass case attached and kickstand closed.
[0009] FIG. 5 is an exploded view of the preferred embodiment of the case seat assembly
[0010] FIG. 6 is a perspective view the preferred embodiment of the case seat assembly.
[0011] FIG. 7A is a back view of the preferred embodiment of the case seat assembly.
[0012] FIG. 7B is a front view of the preferred embodiment of the case seat assembly.
[0013] FIG. 7C is a side perspective view of the preferred embodiment of the case seat assembly.
[0014] FIG. 7D is a frontal perspective view of the preferred embodiment of the case seat assembly.
[0015] FIG. 8 is an exploded view of the preferred embodiment of the case seat assembly
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring to FIGS. 1 and 5 , there are shown exploded embodiments of the case seat assembly ( 5 ) according to the present invention. As shown in one embodiment in FIG. 4 , the present invention comprises a base ( 15 ) with a back side that is attached to the surface of the case ( 90 ), a rotatable housing ( 25 ), kick stand ( 55 ) and a clamp fastener defined by upper portion ( 35 , 36 ) and lower portion( 40 , 50 ). As shown in the preferred embodiment in FIG. 6 , the present invention comprises a base ( 115 ) with a back side that is attached to the surface of the case ( 90 ) a rotatable housing ( 125 ), kick stand ( 155 ) and a clamp fastener defined by upper portion ( 135 , 136 ) and lower portion( 140 , 150 ). In the preferred embodiment the rotatble element ( 145 ) is disposed within the housing ( 125 ).
[0017] In the embodiment, depicted in FIG. 1 is an exploded view of the case seat assembly ( 5 ) of the present invention. Base ( 10 ) can have a circular, oval, elliptical or polygonal shape. In some embodiments base ( 10 ) can be permanently attached to the outer surface of the case ( 90 ) as shown in FIGS. 3 and 4 using some type of adhesive or in alternative embodiments base ( 10 ) can be removable mounted to the outer surface of case ( 90 ) using fasteners such as magnets and Velcro.
[0018] As shown is FIG. 1 , coupling portion ( 15 ) has one side that is permanently affixed to the back side of base ( 10 ) and the opposite side forms a male attaching element. Female attaching element ( 20 ) interconnects with the male attaching element incorporated within coupling portion ( 15 ) and can be removably attached therefrom. Housing ( 25 ) has an underside that forms a compartment for receiving female attaching element ( 20 ) and coupling portion ( 15 ) therein. Housing ( 25 ) forms a cover with an exposed face that is rotatably mounted with one side of the clamp fastener. As shown in FIG. 1 , housing ( 25 ) is configured with a rotatable element ( 26 ) which interconnects through a centrally located aperture ( 41 ) within clamp portion ( 40 ) to mating rotating elements ( 45 ). As shown in FIG. 2 , housing ( 25 ) rotating connection allows clamp fastener to rotate 360 degrees in relation to housing ( 25 ). In alternative embodiments, rotatable element ( 26 ) can be configured to rotate in step increments of 30 degrees.
[0019] Clamp fastener is formed with an upper portion ( 35 , 36 ) and lower portion ( 50 , 40 ). As shown in FIG. 2 , the upper portion comprises opposing levers ( 35 , 36 ) that is hingedly connected through rod element ( 65 ) in a spaced apart relationship. The bottom portion of the clamp fastener comprises opposing tongs ( 40 , 50 ) that are adjacent and abuts each other as they extend linearly downward in a parallel arrangement. The backside of tong ( 40 ) is rotatably mounted to housing ( 25 ) and the backside of tong ( 50 ) has a recessed portion ( 37 ) incorporated therein for receiving kickstand ( 55 ). At the upper end of kickstand ( 55 ) is hinge connection ( 60 ) which allows kickstand ( 55 ) to swing backward and forward within recessed portion ( 37 ).
[0020] Kickstand ( 55 ) is a device that allows the case ( 90 ) to be kept upright without leaning against another object or the aid of a person. In use, kickstand ( 55 ) is a bar that flips down from recessed portion ( 37 ) and makes contact with a flat surface. As shown in FIG. 3 , kickstand ( 55 ) extends outward forming a small angle less than 90 degrees to hold the case in an upright position.
[0021] Depicted in FIG. 5 is an exploded view of the preferred embodiment of case seat assembly ( 205 ) of the present invention. Base ( 110 ) can have a circular, oval, elliptical or polygonal shape. In some embodiments base ( 110 ) can be permanently attached to the outer surface of the case ( 90 ) using some type of adhesive or in alternative embodiments base ( 110 ) can be removable mounted to the outer surface of case ( 90 ) using fasteners such as magnets and Velcro.
[0022] As shown is FIG. 6 , coupling portion ( 115 ) has one side that is permanently affixed to the back side of base ( 110 ) and the opposite side forms a male attaching element. Female attaching element ( 20 ) interconnects with the male attaching element incorporated within coupling portion ( 115 ) and can be removably attached therefrom. Housing ( 125 ) has an underside that forms a compartment for receiving female attaching element ( 120 ) and coupling portion ( 115 ) therein. Housing ( 125 ) forms a cover with an exposed face that is rotatably mounted with one side of the clamp fastener. Opposing edges ( 118 , 119 ) of housing ( 125 ) engages with channels ( 116 , 117 ) of coupling member ( 115 ). Housing ( 125 ) can slide in and out of coupling member ( 115 ).
[0023] As shown in FIG. 5 , housing ( 125 ) is configured interconnects through a centrally located aperture ( 141 ) within clamp portion ( 140 ) to mating rotating elements ( 145 ). Rotating elements ( 145 ) comprises a plug ( 126 ) which is flushed with at least one washer to absorb friction. In the depicted embodiment there are two finger spring washers. Mating plug element ( 127 ) extends through the aperture in the front side tong of clamp fastener to securely engage with plug ( 126 ) wherein rotating element ( 145 ) is operationally coupled thereto. As shown in FIG. 2 , housing ( 125 ) rotating connection allows clamp fastener to rotate 360 degrees in relation to housing ( 125 ). In alternative embodiments, rotatable element ( 126 ) can be configured to rotate in step increments of 30 degrees. In the preferred embodiment, rotating element ( 145 ) can swivel left and right but not 180 degrees. In the preferred embodiment plug ( 126 ) is a swivel plug which allows the housing and the coupling member to swivel left and right. Magnet ( 130 ) can be installed within aperture ( 135 ) directly above aperture ( 141 ). Magnet ( 130 ) can be neodinium with an adhesive pad. Magnet ( 130 ) can provide a magnetic field to secure the washers and plug ( 126 ) within aperture 141 .
[0024] Clamp fastener is formed with an upper portion ( 135 , 136 ) and lower portion ( 150 , 140 ). As shown in FIG. 5 , the upper portion comprises opposing levers ( 135 , 136 ) that is hingedly connected through rod element ( 165 ) in a spaced apart relationship. The bottom portion of the clamp fastener comprises opposing tongs ( 140 , 150 ) that are adjacent and abuts each other as they extend linearly downward in a parallel arrangement. The backside of tong ( 140 ) is rotatably mounted to housing ( 125 ) and the backside of tong ( 150 ) has a recessed portion ( 137 ) incorporated therein for receiving kickstand ( 155 ). At the upper end of kickstand ( 155 ) is hinge connection ( 160 ) which allows kickstand ( 155 ) to swing backward and forward within recessed portion ( 137 ).
[0025] Kickstand ( 155 ) is a device that allows the case ( 90 ) to be kept upright without leaning against another object or the aid of a person. In use, kickstand ( 155 ) is a bar that flips down from recessed portion ( 137 ) and makes contact with a flat surface. As shown in FIG. 5 , kickstand ( 155 ) flips outward forming a small angle less than 90 degrees to hold the case in an upright position. Kickstand ( 155 ) can be used in landscape or portrait mode. Additionally, in other embodiments, the lower end of kickstand ( 115 ) can be removed and made of soft plastic, rubber or another suitable gripping material.
[0026] In use as shown in FIGS. 3, 4 and 6 , clamp fastener is configured to hold or secure case ( 90 ) tightly to a belt, purse or visor. As depicted initially, base ( 10 ) and ( 110 ) are attached to case ( 90 ). Referring to FIG. 6 , then, inward pressure is applied to levers ( 135 , 136 ) thereby forcing tongs ( 140 , 150 ) outward to secure an item therein when opposing levers ( 135 , 136 ) are released. Referring to FIGS. 3 and 4 , in use, inward pressure is applied to levers ( 35 , 36 ) thereby forcing tongs ( 40 , 50 ) outward to secure an item therein when opposing levers ( 135 , 136 ) are released. To stand the case ( 90 ), kickstand ( 55 , 155 ) is extended outward to allow case ( 90 ) to stand upright on a flat surface as illustrated in FIGS. 3, 4 and 5 . | The present invention provides a case seat assembly that is removably attached to a small case containing small items such as eyeglass case, cellphone case, or another small case. The assembly further comprises a base, clamp, and a kickstand. The base is coupled to the outer surface of the small case. Mounted to one side of the clamp is an attaching element that is configured to be rotatably and removably coupled to the base. While in use the clamp is detached from the small case and configured to attach a sun visor, belt, bag, purse or other suitable item. The clamp further comprises a hingedly connected kickstand that allows the case to be suspended in an upright position and the clamp can be detached from the base. | 5 |
BACKGROUND OF THE INVENTION
1. Technical Field
This device relates to apparatus barriers that are used to absorb and dissipate the impact energy of moving vehicles upon impact. More specifically the device relates to energy absorbing structures that have multiple deformable devices within that successfully absorb the impact of vehicles without traumatic injury to the occupants and damage to the structure which the barrier protects.
2. Description of Prior Art
As it is know, urban and country roads usually comprise numerous dangerous zones where there are rigid obstacles such as pillar bridge abutments, paraphets, and lighting poles and the like. In order to prevent an impact against these obstacles from causing serious damage to the occupants of an impacting vehicle, there are conventionally provided impact absorbing systems generally called "crash cushions", specifically designed for absorbing the vehicle impact energy so as to decrease the speed of the vehicle thereby reducing the effects of impact on the vehicle occupants.
Since the danger for these occupants is mainly due to the de-acceleration rate, it is particularly important that such crash cushions give a constant performance in different speed conditions and specifically a constant force as response to the impact force.
The constant response force is the ideal case where the length of the device is minimized and the safety requirements are optimized. This force results from a compromise since it should be high enough to stop the heaviest car usually having a mass of 2,000 kgs and low enough to stop the smallest car usually having a mass of 900 kgs, for example, without generating excessive acceleration on the occupants.
Prior art impact dissipation devices are well known based on a variety of different momentum transfer concepts, see for example U.S. Pat. Nos. 3,643,924, 3,674,115, 3,845,936, 3,982,734, 4,352,484, 4,674,911, 5,011,326, 5,078,366, 5,125,762, 5,192,157, 5,391,016 and European patent application Ser. No. 81200664.1 and PCT application W094/05527 for a liquid, sand or air are used as crushable and deformable materials together with plastic deformation of rigid materials such as steel and the like. Additionally, other energy absorbing materials are used such as rigid plastic foam, aluminum pipes or combinations of same.
SUMMARY OF THE INVENTION
An energy absorbing barrier to provide improved impact attenuation using the plastic deformation principal which defines an easy and convenient way to absorb energy. This principal can be manipulated to get the required linear force response with the use of commonly available materials that are recyclable after impact.
This was achieved by studying a particular configuration of a metal plate, the metal being steel or aluminum or any other which can show a ductile behavior and therefore show a curve stress/strain with a top part after yield point as an arc of large radius in such a way to deliver an approximately constant force which is the ideal characteristic for an energy absorber.
It has been discovered after studies and tests that a plate of suitable thickness shaped to a diamond or superior polygon, compressed on vertexes delivers such performance.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the energy absorbing device of the invention;
FIG. 1A is an enlarged perspective view of a portion of FIG. 1;
FIG. 2 is a perspective view of the configured impact plate of the invention;
FIG. 3 is a top plan view of the configured impact plate shown in FIG. 2;
FIG. 4 is a theoretical graphic representation of a part of a diamond squashed on its top vertex;
FIG. 5 is a schematically arranged illustration of the diamond shape as a beam fixed at one end illustrating applied load forces;
FIG. 6 is a schematically arranged illustration of a flexural deformation in the fixing point;
FIG. 7 is a graphic representation for a ductile material;
FIG. 8 is a graphic illustration of the displacement of the opposing forces;
FIG. 9 is a side elevation of the rear anchor with portions broken away;
FIG. 10 is a top plan view of the rear anchor illustrated in FIG. 9; and
FIG. 11 is an end view of the rear anchor shown in FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 of the drawings, a modular energy absorption barrier assembly 10 can be seen having multiple pairs of ground engaging support uprights 11-14 interconnected to one another by overlapping side panels 15 which are preferably of a typical corrugation guard rail configuration well known to those skilled in the art and are secured to the aforementioned uprights 11-14 by interengaging slides 16 fixed to the uprights by fasteners sliding in longitudinal slots S formed in the respective side panels 15.
A front impact element 17 is secured to the respective side panels 15 adjacent the front pair of support uprights 11. A rear anchor support 18 is anchored to the soil S and defines the anchor point of the system. The rear anchor support 18 has deformable side spacer elements 19 to control side impact at this point.
A pair of soil engagement anchor posts 20 with pre-stress cables 21 extending therefrom secures the barrier to the ground as is typical within the art. The cables 21 are connected to cable retention brackets 22 on a base plate 23 of the rear anchor support 18 which has an inclined I-beam 24 extending therefrom as best illustrated in FIGS. 9 and 10 of the drawings. The inclined I-beam 24 is engageable with an intermediate I-beam 25 and provides the additional advantage by plastic deformation in the case of impact that is greater than that of the designed impact energy of the system as will be hereinafter described in greater detail.
The multiple pairs of support uprights 11-14 are in longitudinally spaced relation to one another between the respective side panels 15 defining energy absorbing compartments 26 therebetween.
The energy absorbing barrier assembly 10 thus described is constructed according to the criteria set forth in U.S. patent application Ser. No. 503,729 (Muller et al) and therefore further delineation and explanation of the structure illustrated therein is not required.
The present invention sets forth an improved means for energy absorption within the defined energy absorbing compartments 26 of the barrier assembly 10 and that the present invention is directed to an energy dissipation plate assembly 27, best seen in FIGS. 2, 3, and 4 of the drawings.
The energy dissipation plate assembly 27 defines a hexagon shape by coupling two identically shaped elements 28 together. Each of the shaped elements 28 is obtained by bending an initially flat rectangular metal shape into multiple angular offset angles 29 and 30 in spaced relation to one another adjacent its respective free ends 31 and 32 with an intermediate portion 33 left therebetween. The pair of the shaped elements 28 are joined together in abutting relationship at their respective ends 31-32 by engagement to bearing flanges 34 by welding thereto, that have a plurality of mounting apertures A therein.
The assembled energy dissipation plates 27 are positioned respectively within the energy absorbing compartments 26 by a plurality of fasteners F to the respective support pairs 11-14 in the barrier assembly 10.
It will be apparent to those skilled in the art that the plates 27 can also be fabricated out of a plurality of thin milled plates to achieve the same structural result.
The energy dissipation plates 27 provide an improved energy absorbing structure when used in multiple units so that they are sequentially engaged by the impact of a vehicle against the barrier assembly 10 (not shown).
Referring now to FIGS. 4-8 of the drawings, a supporting theoretical demonstration is illustrated wherein basic structural form of the assembled energy dissipation plates is illustrated as part of a diamond squashed on its top vertex (see FIGS. 4 and 5 of the drawings) and arranged schematically as a beam fixed at the bottom end loaded with force F applied to the top point P.
Therefore the maximum moment in the fixing point; M=F/b=F/1 cos θ.
Point P starts to move sensibly at yield, i.e. when applied force F reaches yield point; F y =M y /b and M y =σ y w; where w=modulus of the section σ y =yield stress (variable during the application of the force).
Referring now to FIG. 6 of the drawings, we consider now the flexural deformation of the fixing point for sensible movement of the point P, being t=thickness of the beam; ε=t/2 sin θ/2 and the typical diagram σ/ε for a ductile material is represented in FIG. 7 where A o =is the yield point stress.
We can approximate the top part of the diagram as o=A o +A sin ε, where A=work hardening.
Therefore:
σ.sub.y =A.sub.o +A sin (t/2 sin θ/2)
and
F.sub.y =(w/l cos θ) σ.sub.y =w/l ((A.sub.o +A sin (t/2 sin Θ/2))/cos θ).
If we give now "representative" values for standard steel to A o , A and t: A o =40 kg/mm 2 ;A=15 kg/mm 2 ;t=15 mm neglecting constant term w/l, we have;
0=45 40 35 30 25 20 15 10 5 0
F y =41 40.5 40.7 40.6 40.5 40.4 40.2 40.2 40.1 40
As a conclusion, during the movement, the yield force F y can be considered constant and the diagram F/s is represented in FIG. 8 as being the displacement of the applied force F.
In operation, upon a front impact of the vehicle (not shown) the cables 21 operate to control the displacement of the barrier 10 while substantially holding barrier shape constant and providing a comparatively small resilient deformation in the case of a side impact. It will be apparent from the above description that as the vehicle impacts the front of the plate 4 of the barrier 10, the side panels 15 telescopically collapse linearly and simultaneously the energy dissipation plates 27 absorb energy as they are collapsed successively as the impact event continues, the overall de-acceleration of the vehicle is achieved and the minimization of acceleration of the vehicle's occupants is evident so that by the sequential crushing of the energy dissipation plates 27 the effective end result is achieved.
It will be apparent to those skilled in the art that the shaped elements 28 can be formed from multiple plate members of reduced thickness that when combined in multiple packets will emulate the given thickness of the hereinbefore described shaped elements 28 and 34 respectively.
It will thus be seen that an improvement to a crash barrier has been illustrated and described wherein a new and novel energy dissipation plate has been illustrated and described and it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention. | An energy absorption apparatus to dissipate impact force of a vehicle and to protect fixed objects near highway by safely stopping the vehicle. A plurality of energy absorbing metal plates are configured in such a way that by applying the force of impact of a vehicle that they successfully collapse absorbing the impact forces. | 4 |
PRIORITY CLAIM
[0001] This application is a Continuation of U.S. patent application Ser. No. 11/650,033, filed Jan. 5, 2007, entitled Multimedia Object Grouping, Selection, and Playback System.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to a multimedia object organization and playback system. In particular, the present invention relates to a multimedia object organization and playback system that groups objects heuristically and allows playback based on similarities between the grouped objects.
[0004] 2. Related Art
[0005] Enormous growth in digital technology has given rise to vast collections of information, including music and multimedia objects, such as files and data streams; phone, personal, or restaurant contacts; news articles; photographs; and many other types of data files. For example, fast processors, Internet music stores, and almost boundless and inexpensive data storage have given the everyday individual the ability to build an extensive digital collection of music. At the same time, advanced music players have taken on the challenge of providing convenient access to the hundreds or thousands of songs that may be in such a collection.
[0006] Music objects may be organized based on pre-defined or user-defined designations, such as an artist, album, or genre of the music. For example, MP3 or other music object types may include ID3 tags associated with the music object. The organized music objects may be stored in playlists based on the designations, and may be transferred to music players and played back based on the playlist or designation.
[0007] The user interface on a music playback device typically displays a list of tagged objects that are stored or available on the device. However, the user interface typically presents only simplified views of the objects, such as displaying the entire list of objects, or lists of objects restricted by a limiting selection. For example, the objects may be displayed in alphabetical order, or they may be displayed according to a genre or artist selection. Once the objects are tagged or catalogued, the listener may decide what objects to listen to using the user interface.
[0008] Listeners may be interested in playing a small number of groups of music, where each group is similar by some musical or psychological attribute. Conventional user interface applications for data object lists do not allow groupings of objects other than by pre-defined designations and categories. Other limited playback features may also be present. As one example, the user interface may permit a listener to select random shuffle playback. Another option often provided is to permit playback from a manually defined and entered playlist of songs. In other words, conventional user interfaces provided insufficient playback flexibility in many situations. The explosive growth of digital music collections exacerbates this problem.
[0009] Therefore a need exists for a system that allows grouping of objects based on heuristic characteristics and allows playback of music objects based on such a grouping to improve the music selection and playback experience.
SUMMARY
[0010] A multimedia organization and playback system intelligently organizes information and delivers the information on request. The information may be present in virtually any type of storage mechanism, including music files, streaming music objects, address entries, video objects, telephone contacts, restaurant selections, or other types of objects. In the context of a music object organization and playback system, for example, the system may intelligently deliver a selection of music to the listener in which each song is chosen to be consistent with the last song, or more or less similar to the last song.
[0011] A music object organization system assigns music objects to groups based on heuristic characteristic of the music objects. The music object organization system determines music object groups based on a music object characteristic, such as a genre, album, artist, or music object length. The music object organization system identifies a heuristic distance measure applicable to the music objects, and assigns the music objects among the music object groups to satisfy a clustering criterion, such as a minimization of the heuristic distance measures between music objects within the music object groups.
[0012] A music object playback system that may be used with the music object organization system presents a music object group as a selectable “channel” to the listener. The music object group may be organized based on a music object characteristic associated with the music objects. The system organizes the music object groups such that a heuristic distance measure between the music objects satisfies a clustering criterion, such as a minimization of the heuristic distance measures between music objects within the music object groups. The music object playback system determines which music objects are candidates for selection as the next music object to play from the music object group by adjusting a next music object selection space based on a maximum heuristic distance measure. Then, actual selection is at random, in alphabetical order, by track length order, or by any other selection criteria in the space. A listener may select a music object that is “more like” a currently playing music object, in which case the system reduces the next music object selection space. The listener may also select a music object that is “less like” the currently playing music object, in which case the system expands the next music object selection space.
[0013] A graphical user interface for the system presents a “more like this” user interface element through which an operator reduces a next music object selection space to select a next music object that is “more like” the currently playing music object. A “less like this” user interface element is also presented, through which an operator expands the next music object selection search space. The operator may select a next music object that is “less like” the currently playing music object using the “less like this” user interface element.
[0014] Other systems, methods, features and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the invention, and be protected by the following claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like-referenced numerals designate corresponding parts throughout the different views.
[0016] FIG. 1 is an example heuristic map of music objects.
[0017] FIG. 2 is a music object organization system.
[0018] FIG. 3 is a music object playback system.
[0019] FIG. 4 is an example of heuristic distance measures.
[0020] FIG. 5 is a music object selection space based on the heuristic distance measures of FIG. 4 .
[0021] FIG. 6 is an example of heuristic distance measures.
[0022] FIG. 7 is a music object selection space based on the heuristic distance measures of FIG. 6 .
[0023] FIG. 8 is an example of heuristic distance measures.
[0024] FIG. 9 is a schematic diagram of a music object selection space based on the heuristic distance measures of FIG. 8 .
[0025] FIG. 10 illustrates a graphical user interface.
[0026] FIG. 11 shows the acts the music object organization system takes to group music objects based on a music object characteristic.
[0027] FIG. 12 shows the acts the music object organization system takes to satisfy a clustering criterion for the music objects.
[0028] FIG. 13 shows the acts the music object playback system takes to select and play a next music object.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Music listeners may not desire to listen to a musical collection as a random collection of tracks. Music listeners may be interested in listening to one of a small number of groups of music, where each group is similar by some attribute, such as a musical or psychological attribute. Listeners may desire to organize a music collection based on heuristic music object characteristics associated with the music objects in the music collection, such as by grouping music objects that are more similar to each other than to other groups of music objects. Such a heuristic grouping may allow for a continuum of music object organization based on music object characteristics associated with the music objects.
[0030] FIG. 1 is an example heuristic map 100 of music objects. The map 100 locates music objects in an n-dimensional space, such as a vector space, starting with giving each music object a location in this space. Each axis of the n-dimensional space may be based on a music object characteristic, or combination of characteristics, associated with the music objects. The music objects may be represented in the vector space as ordered n-tuples, where n may be an integer greater than 0. Vectors in these spaces may be ordered “tuples” of real numbers. A pair of music objects, such as two classical music objects, may be located “close” to each other in the space, whereas another pair, such as a classical music object and punk rock music object, may be located “far” from each other in the space.
[0031] One way of assigning locations to each music object may include determining or obtaining a genre tag of each music object, and comparing the information in the genre tag to a two-dimensional map of genres to locate the music object. For example, a “tag” object associated with the music objects may be processed, such as by extracting music object characteristics from an ID3 tag associated with the music object. The music object's resulting location may be related to the location of that genre on the map. For example, given the example heuristic map 100 shown in FIG. 1 , a rock song 102 would have the location of (1,1), and a jazz song 104 would have the location of (−1,1). Other mappings are possible, including mappings of the music objects in more than two-dimensional space. For example, additional music object characteristics may include an artist, album, composer, music object length, beat-per-minute count, time period, and/or a user-defined characteristic for a music object. The music objects may adhere to the WAV, MP3, WMA, OOG, AAC, AIFF, or other music object formats. The music objects may also include streaming objects such as satellite radio objects, streaming audio objects, objects stored on a server and streamed to a device, high definition radio objects, cellular-transmitted audio objects, or other audio objects streamed over a wired or wireless connection.
[0032] The heuristic map 100 may be determined by a listener's preferences and selection of music object characteristics. The listener may set locations for music objects within the heuristic map 100 as a pre-processing operation, or during operation using a graphical user interface (GUI). In some systems, one or more heuristic maps 100 may be pre-defined (e.g., as a system default heuristic map) and installed or loaded in a memory in the system at a factory or original equipment manufacturer (OEM) location. The system may receive operator input that switches between the currently active map during system operation. In other systems, an expert system may be configured to analyze the music objects and determine the heuristic map 100 . The heuristic map 100 may be based on listener statistics, such as previously played music objects, ranked lists of music objects, subscriptions to music object services, and/or other behavioral statistics that may determine a heuristic map of music objects.
[0033] FIG. 2 illustrates an example music object organization system 200 (“system 200 ”). The system 200 may organize music objects based on a music object characteristic associated with the music objects to create heuristic groupings of music objects. The system 200 may present the heuristic groupings to a listener for selection. The system 200 includes a system processor 202 , a system co-processor 203 , and a user interface 204 configured to accept input and present output to a listener. The system 200 also includes a system memory 206 , databases 208 configured to retain data related to system operation, a display 240 , and a communications interface 250 . As will be discussed in more detail below, the system processor 202 may execute music object organization logic 230 to organize the music objects based on the music object characteristic associated with the music objects, for example.
[0034] The system co-processor 203 may assist with the execution of instructions by the system processor 202 . The system co-processor 203 may be implemented as a math co-processor to execute analysis or statistical programs associated with the music object grouping. The system co-processor 203 may be integral with the processor 202 , or may be a separate processor.
[0035] The user interface 204 accepts input from a listener. A listener may desire to view a list of music objects, search the music objects, enter data for input to the system 200 , select applications, play a music object, define new or modify existing heuristic maps, or take other desired actions. The user interface 204 may include an interface display 205 configured to display user interface elements for viewing and/or selection. The user interface 204 may include one or more selectors 207 , such as buttons, actuable by the listener to select an action or to enter data. The user interface 204 may also include a user input logic 209 . The user input logic 209 may include a mouse, keyboards, keypads, touchpads, styli, light pens, microphone inputs, wireless receivers, remote input, trackpads, trackballs, joysticks, track pointers, haptic modules, force-feedback modules, motion detectors, biomeasure input modules, and/or other input modules. The user interface 204 may be coupled wirelessly to the system 200 , such as through a Bluetooth, infrared, WiFi, RF, cellular connection, and/or other wireless connection. Alternatively or additionally, the user interface 204 may be coupled by a wired connection to the system 200 , such as through an Ethernet, RCA, USB, FireWire, or other wired connection. In some systems, the user interface 204 may be integral with the system 200 .
[0036] The system memory 206 may include a music object information database 210 . The music object information database 210 may include data records related to the music objects, each data record containing fields together with a set of operations for searching, sorting, recombining, and/or other functions related to the fields and data records. For example, the music object information database 210 may retain the music object characteristics associated with the music objects such as a genre field 212 , an album field 213 , an artist field 214 , a beats-per-minute field 215 , a time period field 216 , and/or a user field 217 , such as a user-defined or user-configurable field. Additional, fewer, or different data records associated with the music objects may be stored in the memory 206 . The music object information database 210 may store an ID3 tag or other metadata container associated with a music object. The music object information database 210 may be editable, or may be locked or read-only.
[0037] The interface control logic 220 may include instructions that control and accept input from the user interface 204 . The interface control logic 220 may process input from the selectors 207 or the input module 209 to control the system 200 . The interface control logic 220 may include instructions to process actions selected through the user interface 204 . For example, the interface control logic 220 may display a list of music objects available in the music object information database 210 , or may allow a listener to search or select a desired music object or group of music objects. In some systems, the interface control logic 220 accepts input from the user interface 204 to organize the music objects into groups based on the music object characteristics associated with the music objects.
[0038] The user interface generation logic 225 may include instructions that cause the user interface 204 to display user interface elements on the interface display 205 or the display 240 . Examples of user interface elements include screen window panes, soft keys, touchscreen elements, soft buttons, scroll bars, dials, and/or other graphical interface elements. The instructions may be calls to graphical user interface libraries, draw primitives, graphical libraries, or other user interface element instructions.
[0039] The music object organization logic 230 may include instructions that organize the music objects into groups based on the music object characteristics associated with the music objects. The music object organization logic 230 may be implemented as processor executable instructions, executed by the system processor 202 , to determine groups of music objects, such as at least a first group of music objects and a second group of music objects. These groups may represent the common listening styles preferred by the listener. The groups may be based on the heuristic map 100 . The music object organization logic 230 may identify a heuristic distance measure applicable to the music files, such as a heuristic distance measure based on the heuristic map 100 . The heuristic distance measure may be a function of the ordered n-tuples associated with the music objects in the vector space associated with the music object characteristics. For example, the heuristic distance measure may be defined as a geometric distance between the music objects in the vector space:
[0000] D H =√{square root over (( x 1 −x 2) 2 +( y 1 −y 2) 2 +( z 1−z2) 2 + . . . +( q 1 −q 2) 2 )}{square root over (( x 1 −x 2) 2 +( y 1 −y 2) 2 +( z 1−z2) 2 + . . . +( q 1 −q 2) 2 )}{square root over (( x 1 −x 2) 2 +( y 1 −y 2) 2 +( z 1−z2) 2 + . . . +( q 1 −q 2) 2 )}{square root over (( x 1 −x 2) 2 +( y 1 −y 2) 2 +( z 1−z2) 2 + . . . +( q 1 −q 2) 2 )} Eqn. 1
[0000] where D H is the heuristic distance measure, {x1, y1, z1, . . . q1} may represent a location of a first music object in the vector space, and {x2, y2, z2, . . . q2} may represent a location of a second music object in the vector space. The music object organization logic 230 may determine the heuristic distance by determining an n-dimensional scalar magnitude of a vector between the music objects within a group. The heuristic distance measure may include a similarity measure between the music objects, where music objects with a smaller heuristic distance measure separating them may be considered “more similar.” Other functions for D H may be possible, where coordinates of the ordered n-tuples are mapped from the music object characteristics. The music objects may be ordered in the heuristic map to form a vector space, where the music objects satisfy mathematical relations related to vector operations on the music objects.
[0040] The music object organization logic 230 may determine the groups by assigning each music object among at least the first music object group and the second music object group such that heuristic distance measures between the music objects satisfy a clustering criterion. In some systems, the clustering criterion comprises a minimization of the heuristic distance measures between the music objects within a group. The music object organization logic 230 may organize the music objects within a group such that an intra-group variance of the music objects is minimized.
[0041] The music object organization logic 230 may use an expectation-maximization process to group the music objects. The music object organization logic 230 may use a k-means process. The k-means process groups objects based on attributes, such as the music object characteristics, into k initial partitions. The music object organization logic 230 may determine a number k means of data generated from distributions (such as Gaussian distributions) of the music objects in the vector space. The music object organization logic 230 may minimize a total intra-group variance, or, a squared error function:
[0000]
V
=
∑
i
=
1
k
∑
j
∈
S
i
x
j
-
μ
i
2
Eqn
.
2
[0000] where there are k groups S i , i=1, 2, . . . , k, and μ i is the centroid or mean point of all the points x j εS i . In the system 200 , x j may represent a music object available for organization. The music object organization logic 230 may set the number of groups based on a determined music object characteristic, such as a pre-determined or user-determined number of groups. The music object organization logic 230 may set the number of groups based on the heuristic map 100 . In some systems, the music object organization logic 230 may adjust the number of groups dynamically, such as by allowing an operator to set the number of groups.
[0042] The music object organization logic 230 partitions the input points into k initial groups, either at random or using some heuristic data. The music object organization logic 230 then calculates the mean point, or centroid, of each group. The music object organization logic 230 determines a new partition by associating each point, or music object, with a closest centroid. Then, the centroids are recalculated for the new groups. The music object organization logic 230 may repeat the process by alternate application of these two steps until convergence of the process is reached, which may be obtained when music objects no longer switch clusters (or alternatively, when centroids are no longer changed).
[0043] The music object organization logic 230 may store the groups of music objects, determined during the organization process, in the system memory 206 . The system 200 may display the groups of music objects on the display 240 . The listener may select a group for playback, view group characteristics, select a repeat of the organization process, and/or other actions.
[0044] The music object information 210 may additionally or alternatively be obtained from databases 208 , through operator input at the user interface 204 , through a communication interface 250 (e.g., through a network connection to a data warehouse, to equipment in the system 200 , such as storage, server, computer, or to other logic), or from other sources. As examples, the databases 208 may be local or remote databases that store music object information, program module code means, or system music object characteristic information.
[0045] The system 200 may organize the music objects within the group so that all of the music objects are “close” to each other by a heuristic measure. For example, the system 200 may organize music objects that have a “genre” music object characteristic of “classical” within a group. Music objects that have a “classical” genre music object characteristic and that also have the same “album” music object characteristic and “artist” music object characteristic may be considered “closer” heuristically than music objects that have a “classical” genre and the same “artist” music object characteristic but have a different “album” music object characteristic. A listener may configure the system 200 to organize music objects closer within a group based on different music object characteristics. The listener may set the music object organization logic 230 to initially place the music objects within the groups. In some systems, the music object organization logic 230 may load a mapping template, such as the heuristic map 100 , or a set of rules to place the music objects within the vector space.
[0046] When the system 200 organizes the music objects into groups, the listener may play the music objects. FIG. 3 illustrates a music object playback system 300 (“system 300 ”) that may present the organized groups to the listener and allow playback of a selected group of music objects. The music object playback system 300 may include a user interface 304 , a system memory 306 configured to retain a music object playback logic 340 , user interface generation logic 345 , databases 308 that contain data related to the music object information and equipment information, and speakers 380 . In FIG. 3 , when the listener selects an action, such as by using the user interface 304 , the system 300 may display the next music object on the display 240 and/or the interface display 305 . The system 300 may play the next music object on the speakers 380 .
[0047] The system 300 may present a list of groups of music objects to the listener as selectable “channels” to listen to. The user interface generation logic 345 may present the list of groups on the display 240 and/or the user interface 304 . The system memory 306 may retain channel assignment logic 350 that maps the groups to channel names that the user interface 304 displays. The channel assignment logic 350 may assign channel names, such as Group 1->“Channel 1,” Group 2->“Channel 2,” etc. Other channel assignments may be possible, such as assignments based on the heuristic map 100 , user-selected channel mappings, or other assignments. The user interface generation logic 345 may be implemented as instructions that cause the interface display 205 and/or the display 240 to display user interface elements. The listener may select a group of music objects, and may select a music object from within the group for playback, using the user interface 304 . Alternatively, the system 300 may randomly select a music object for playback when the listener selects a group. For example, the system 300 may randomly choose a starting music object with uniform probability from all the music objects in the group, and begin playback.
[0048] Once playback has begun, the system 300 may present the listener with playback controls that direct the system 300 to take specific actions. The listener may use the user interface 304 , such as by actuating selectors 307 or other user input 309 , to select an action. For example, the listener may activate a “track forward” control to direct the system 300 to play a next music object in the group. Other examples of playback controls include a “less similar” playback control and a “more similar” playback control. The listener may also allow the current music object to play to the end of track, “EOT.”
[0049] The listener may also indicate to the system 300 that the listener desires to next hear a song that is “less like” or “less similar” to the currently playing music object. In this case, the listener may desire a music object within the group that sounds less like the currently playing music object. A “less similar” song may be determined based on song characteristics such as album, artist, genre, beats-per-minute, music object length, time period, and/or a different user-defined field associated with the music object.
[0050] The listener may also indicate to the system 300 to select a music object within the group that sounds “more like” or is “more similar” to the currently playing music object. Such a song may be determined based on song characteristics such as album, artist, genre, beats-per-minute, time period, music object length, and/or a different user-defined associated with the music object.
[0051] The next music object may be chosen randomly from a set of music objects within a maximum heuristic distance measure from the current music object and within the current group. The maximum heuristic distance is chosen as a function of a heuristic distance scaling factor, K. The music object playback logic 340 may select a next music object to play from the group of objects by adjusting a next music object selection space based on the maximum heuristic distance measure. The next music object selection space may encompass a subset of music objects in the selected group that the music object playback logic 340 may select from based on the maximum heuristic distance measure.
[0052] The music object playback logic 340 may determine a uniform random variable X. The music object playback logic 340 may use a random number generator, a look-up table, or other logic to determine the uniform random variable X. The music object playback logic 340 determines the heuristic distance scaling factor K, where K may be based on a value retained in the system memory 304 , the databases 308 , from listener input, or from a program executed by the processor 202 . The maximum heuristic distance measure D may be determined by the following equation:
[0000]
D
(
X
,
K
)
=
(
100
-
X
)
K
Eqn
.
3
[0000] The system 300 may implement other maximum heuristic distance measure functions.
[0053] The system 300 may also include special purpose processors. For example, one or more Digital Signal Processors (DSPs) 360 may be provided. The DSPs 360 may digitally manipulate signal samples that determine the sound output from one or more speaker system speakers 380 , including applying signal processing algorithms or taking other processing steps. The DSPs 360 may interface with driver logic 370 , such as pre-amplifiers, amplifiers, signal conditioners, or any other logic that influences an audio signal delivered to the speakers 380 .
[0054] FIG. 4 illustrates an example graph 400 of maximum heuristic distance measures as a function of the uniform random variable X. FIG. 4 is a graph of Eqn. 3 with K=50. The system 300 influences the selection space from which the next song will be chosen by changing the K parameter. For a song that is similar to the last song, for example, the system 300 may use a value for K of 50, such that about 50% of the maximum heuristic distances will be 1 or less, and the largest maximum distance is less than 1.5. Once the maximum distance has been determined using X and K, the music object playback logic 340 may randomly choose a music object that has a heuristic distance less than or equal to the determined maximum distance D from the current music object. The result is that subsequent music objects may be similar to the current music object. The system may select similar music objects when the listener uses the track forward control, when the currently playing song ends, or for other reasons.
[0055] FIG. 5 illustrates an example three dimensional heuristic map 500 . FIG. 5 labels the axes 502 , 504 , and 506 for each of the three dimensions. A group of music objects (several of which are labeled 508 , 510 , 512 , 514 , 516 and 518 ) are located in the heuristic map 500 . Based on the example function illustrated in FIG. 4 , a next music object selection space 520 may be represented as a sphere with a radius D 522 , which may represent the maximum heuristic distance measure. The next music object selection space 518 encompasses a set of music objects ( 510 , 512 , 514 , 516 and 518 ) that are located within the radius D 522 of a music object 510 . The music object 510 may represent the currently playing music object. The radius D 522 may be determined based on the heuristic distance scaling factor, such as by using Eqn. 3. In FIG. 5 , radius D 522 may be determined using a heuristic distance scaling factor of K=50, based on the example in FIG. 4 . The music object playback logic 340 may randomly select a next music object to play from the music objects ( 510 , 512 , 514 , 516 and 518 ).
[0056] The music object 508 lies outside the next music object selection space 520 . Because the music object 508 is located a distance greater than radius D 522 from the music object 510 , the music object 508 may be excluded from the next music object selection space 520 . The music object playback logic 340 does not select music objects that lie outside the next music object selection space when the music objects, such as the music object 508 for example, are located a distance greater than the radius D 522 .
[0057] FIG. 6 illustrates an example graph 600 of maximum heuristic distance measures, as a function of uniform random variable X, when the listener desires a next music object that is “less like” or less similar to the currently playing music object. If the listener desires the next music object to be less similar or “less like” the currently playing music object, the music object playback logic 340 may decrease the value of the heuristic distance scaling factor, such as by using a value for K of 25. In this case, there may be only a 20% probability that the maximum heuristic distance measure is less than 1. This probability would indicate that it may now be more likely that the next music object is less similar to the currently playing music object, because the average distance between selected music objects is further. Other values for K may be selected by the music object playback logic 340 .
[0058] FIG. 7 illustrates an example heuristic map 700 based on the example graph of maximum heuristic distance measures in FIG. 6 . Based on the example group illustrated in FIG. 6 , a next music object selection space 724 may be represented as a sphere with a radius D 726 , which may represent the maximum heuristic distance measure. The next music object selection space 724 may include a set of music objects ( 510 , 512 , 514 , 516 , 518 , 720 and 722 ) that are located within the radius D 726 of a music object 510 . Music object 510 may represent the currently playing music object. The radius D 726 may be determined based on the heuristic distance scaling factor, which may be decreased, based on the example in FIG. 6 . In FIG. 7 , the radius D 726 may be determined using a heuristic distance scaling factor of K=25, based on the example in FIG. 6 . In FIG. 7 , the next music object selection space 724 has been increased and includes more music objects to select. The music object playback logic 340 may randomly select a next music object to play from the music objects ( 510 , 512 , is 514 , 516 , 518 , 720 and 722 ). The music object 508 may be excluded from the next music object selection space 724 because the music object 508 is located a distance from the music object 510 that is greater than the radius D 726 , which represents the maximum heuristic distance measure for the next music object selection space 724 . The music object that is selected may therefore be less similar or “less like” the currently playing music object 510 because the maximum heuristic distance measure is larger than the maximum heuristic distance measure in FIG. 5 .
[0059] FIG. 8 illustrates an example graph 800 of maximum heuristic distance measures when the listener desires a next music object that is “more like” or more similar to the currently playing music object. If the listener desires the next music object to be “more like” or more similar to the currently playing music object, the music object playback logic 340 may increase the value of the heuristic distance scaling factor, such as by using a value of K=75. In this case, there may be an 80% probability that the maximum distance is less than 1. This probability would indicate that it is now more likely that the next music object is more similar to or “more like” the currently playing music object, because the average distance between selected music objects is less. Other values for K may be selected by the music object playback logic 340 .
[0060] FIG. 9 illustrates an example heuristic map 900 based on the example graph of maximum heuristic distance measures in FIG. 8 . Based on the example group illustrated in FIG. 8 , a next music object selection space 920 may be represented as a sphere with a radius D 922 , which may represent the maximum heuristic distance measure. The next music object selection space 920 may encompass a set of music objects ( 510 , 512 and 518 ) that are located within the radius D 922 of a music object 510 . The music object 510 may represent the currently playing music object. The radius D 922 may be determined based on the heuristic distance scaling factor, which may be increased, based on the example in FIG. 8 . In FIG. 9 , the radius D 922 may be determined using a heuristic distance scaling factor of K=75, based on the example in FIG. 8 . The music object playback logic 340 may randomly select a next music object to play from the music objects ( 512 and 518 ) in the next music object selection space 920 . The music object playback logic 340 may select a next music object to play that is “more like” or more similar to the currently playing music object 510 . The music objects 514 and 516 lie outside the next music object selection space 920 . The music object playback logic 340 may not select the music objects 514 and 516 because they are located at distances from the music object 510 that are greater than the radius D 922 , which may represent the maximum heuristic distance measure.
[0061] FIG. 10 illustrates an example graphical user interface 1000 . The graphical user interface 1000 accepts input for the music playback system 300 . The graphical user interface 1000 may be presented on a display 1002 that presents data related to applications, group listings, and music object listings. For example, the display 1002 may present windows or display panes, such as an application menu 1003 , a group list menu 1004 , and a playing music object description 1005 . Other data may be presented. Other display formats may be adopted, such as a command line interface, a speech recognition transcription or handwriting recognition transcription pane, or other display formats. The display 1002 may receive stylus input, such as through a touch screen or tablet PC interface. The display 1002 may include the display 240 , or the interface display 205 .
[0062] The graphical user interface 1000 may include one or more user interface elements 1010 - 1014 . The user interface elements 1010 - 1014 may be assigned functions related to playback of the organized groups of music objects. For example, the graphical user interface 1000 may include a “play to end” user interface element 1010 that allows a music object to play until completion of the music object; a “next song” user interface element 1011 that allows selecting a next music object from the group of music objects; a “more like this” user interface element 1012 that allows selecting a next music object that is more similar to or “more like” a playing music object; and a “less like this” user interface element 1013 that allows selecting a next music object that is less similar to or “less like” a playing music object. The graphical user interface 1000 may also include a user interface selector element 1014 to select other actions, to repeat a previous action, to access other data display options, and/or other options. The user interface elements 1010 - 1014 may be defined in a liquid crystal display, or configured as a raster image on a pixelated CRT screen.
[0063] When the listener selects the user interface elements 1010 or 1011 , the system 300 may select the next music object from the existing music object selection space. For example, the system 300 may determine the heuristic distance scaling factor K to be 50, such that about 50% of the maximum heuristic distance measures will be of 1 or less, and the largest maximum distance is less than 1.5. Once the maximum distance D has been chosen, a music object is randomly chosen that has a maximum heuristic distance measure less than or equal to D from the current music object. As a result, subsequent music objects may be similar to the current music object.
[0064] When the listener selects the “more like this” user interface element 1012 , the system 300 may select the next music object by reducing the next music object selection space. FIG. 9 shows an example of reducing the selection space, from the original space 520 to the reduced space 920 . The system 300 may adjust the heuristic distance scaling factor K, such as by increasing K to be 75, for example. Other values of K may be used. The next music object may be more similar to the currently playing music object, because the average distance between selected music objects is less.
[0065] When the listener selects the “less like this” user interface element 1013 , the system 300 may select the next music object by expanding the next music object selection space. FIG. 7 shows an example of expanding the selection space, from the original space 520 to the expanded space 724 . The system 300 may adjust the heuristic distance scaling factor K, such as by decreasing K to be 25, for example. Other values of K may be used. The next music object is less similar to the currently playing music object, because the average distance between selected music objects is greater.
[0066] FIG. 11 illustrates the acts the music object organization system 200 takes to group music objects based on a music object characteristic. The acts illustrated in FIG. 11 may be implemented by the elements of FIG. 2 , such as the processor 202 , the co-processor 203 , instructions or logic retained in the system memory 206 , the databases 208 , and/or programs or logic retained in modules coupled with the system 200 . For example, the organization logic 230 may be implemented with processor executable instructions that implement the acts shown in FIG. 11 when executed by the processor 202 . The system 200 may initialize by loading music objects, processing music object characteristics, and/or network connections (Act 1102 ). The system 200 may prompt for user input during initialization, or the system 200 may execute a boot script to initialize. The system 200 may determine if the music objects are associated with a music object characteristic (Act 1104 ). The system 200 may determine if the music objects are tagged or associated with a genre, artist, album, composer, beats-per-minute measure, music object length, time period and/or a user-defined field. The system 200 may process an ID3 tag or other metadata container associated with the music objects.
[0067] If the music objects are not associated with a music object characteristic, the system 200 may prompt the listener to enter music object characteristics for the music objects (Act 1106 ). In some systems, the listener may be prompted to locate a data file containing music object characteristics to associate with the music objects, or to select an ID3 tag or other identifier containing music object characteristics. If the music objects are associated with a music object characteristic, the system 200 may determine an initial set of groups based on the music object characteristic (Act 1108 ). The system 200 may use the initial groups to assign music objects to the groups based on the music object characteristics associated with the music objects (Act 1110 ). The listener may be prompted to select a music object characteristic to use for the initial groups. In some systems, the system 200 uses a determined music object characteristic and/or a heuristic map to determine the initial groups.
[0068] When the initial groups are determined, the system 200 processes the music objects to satisfy a clustering criterion for the music objects, such as to minimize a heuristic distance measure between the music objects within the group (Act 1112 ). As discussed above, the system 200 may use an expectation-maximization process, such as a k-means process, to process the music objects. The system 200 processes the music objects, as represented in a vector space determined by the music object characteristic associated with the music object, to minimize the heuristic distance measure. The heuristic distance measure between any two music objects in the vector space may be defined as a geometric distance between the music objects, such as a scalar magnitude of a vector between the two music objects in the vector space, or other measure.
[0069] The system 200 may, at a stage of the processing, determine if the heuristic distance measures between the music objects within the group are minimized (Act 1114 ). If the heuristic distance measures are minimized, the system 200 may complete the processing. The system 200 may assign channel names to the groups of music objects (Act 1118 ). The system 200 may assign heuristic names to the groups of music objects based on the heuristic map, from a list of channel names associated with the groups of music objects, or by operator selection. The system 200 may present the channel names to the listener on a GUI for selection (Act 1120 ). If the heuristic distance measures are not minimized, the system 200 may determine if a determined stopping threshold has been reached (Act 1116 ). The system 200 may use a maximum number of process iterations to determine when to stop the object assignment process. The system 200 may use the determined stopping threshold to prevent the system 200 from iterating without bound. The system 200 may return an error message if the stopping threshold has been reached. The system 200 may then present the group of music objects as determined by the system 200 at the time the system 200 ends processing. If the stopping threshold has not been reached, the system 200 may continue to Act 1112 to process the music objects.
[0070] FIG. 12 shows the acts the music object organization system takes to satisfy a clustering criterion for the music objects. The system 200 may use a k-means process to assign the music objects. The system 200 assigns music objects to an initial set of groups (Act 1202 ). The system 200 may use a heuristic map, such as example heuristic map 100 , to assign the music objects to the initial set of groups. The system 200 may use music object characteristics associated with the music objects to determine the initial groups. Alternatively, the system 200 may prompt the listener to select a list of initial groups. Vector space diagram 1203 illustrates four groups ( 1220 - 1223 ) of music objects. For example, based on the initial list of groups, there are seven music objects initially assigned to group 1220 , five music objects initially assigned to group 1221 , five music objects initially assigned to group 1222 , and six music objects initially assigned to group 1223 . Other initial groupings may be possible.
[0071] The four groups ( 1220 - 1223 ) may represent genres of the music objects. Example genres include, but are not limited to, pop, oldies, country, alternative, rock, classical, hip-hop, rap, jazz, opera, contemporary, heavy metal, or other genres. The genres may be determined by an ID3 tag, metadata container, or other identifier associated with the music objects, or may be determined based on listener input. The four groups ( 1220 - 1223 ) may represent other music object characteristics, such as an artist, album, composer, music object length, beats-per-minute count, time period, tempo, a user-defined field, or other music object characteristics. The number of possible groups in the vector space is likewise not limited to four, but may include lesser or greater numbers of groups.
[0072] The system 200 may calculate a “centroid” measure for each group of music objects, based on the initial groups (Act 1204 ). Vector space diagram 1205 illustrates the four centroids of the music objects in the initial groups ( 1220 - 1223 ), illustrated as crosses ( 1233 - 1236 ). The centroid for each group may be determined using a relation such as:
[0000]
Cg
,
x
=
∑
i
=
1
n
w
i
*
x
i
n
Eqn
.
4
Cg
,
y
=
∑
i
=
1
n
w
i
*
y
i
n
Eqn
.
5
[0073] Eqn. 4 represents the x-coordinate of the centroid of the group g, and Eqn. 5 represents the y-coordinate of the centroid of the group g, where (x,y) are coordinates locating the music objects in the vector space determined by the music object characteristics, and n is the number of music objects in group g. Eqns. 4-5 may use a weighting factor w i for each music object. The weighting factor w i may represent a rating, importance factor, or other scaling factor desired by the listener. The system 200 may use ethnomusical preferences, such as maintaining the track order within a performance (e.g., track order in an opera). The weighting factor w i may be adapted to place a next logical track in an album closer in distance than other tracks. The weighting factor w i may take on a value of 1. In FIG. 12 , centroid 1233 represents the centroid of the music objects for group 1220 , centroid 1234 represents the centroid of the music objects for group 1221 , centroid 1235 represents the centroid of the music objects for group 1222 , and centroid 1236 represents the centroid of the music objects for group 1223 . Distances between the centroids ( 1233 - 1236 ) and the music objects within a group are represented as solid lines.
[0074] The system 200 then assigns each music object to a group associated with a closest centroid (Act 1206 ). Vector space diagram 1205 illustrates an illustrative situation where three music objects are closer to a different initial group's centroid (indicated by dashed lines between a music object and a centroid). Music objects 1240 and 1241 are closer to the centroid of group 1222 than to the centroid of group 1220 . Music object 1242 is also closer to the centroid of group 1222 than to the centroid of group 1223 . The system 200 then assigns music objects 1240 and 1241 to group 1222 , and assigns music object 1242 to group 1222 . Other sets of music objects and music object characteristics may generate different placements of the music objects, and may generate different distances between the music objects and the centroids of the groups.
[0075] The system 200 may determine if new groups are created based on assigning each music object to the group associated with a closest centroid (Act 1208 ). If no new groups are created, then the system 200 may determine that the music objects within the groups are assigned such that the heuristic distance measures between the music objects are minimized, and the process ends. The groups may be determined to be the groups to present to the listener for selection.
[0076] If new groups are created based on assigning each music object to the group associated with a closest centroid, then the system 200 may calculate centroids for the newly created groups (Act 1210 ). The system 200 may use Eqns. 4-5 to determine the new centroids. Vector space diagram 1207 illustrates example new groups ( 1251 - 1254 ) based on the re-assigned music objects from vector space diagram 1205 and Act 1206 . Newly determined centroids ( 1230 , 1234 , 1237 , and 1238 ) are illustrated in vector space diagram 1207 , along with vectors (indicated by solid lines) representing distances between the music objects and the centroids ( 1230 , 1234 , 1237 , and 1238 ). The system 200 may then determine if convergence of the process has been reached (Act 1212 ). For the k-means process, convergence may be reached when no music object switches groups during a process iteration. Alternatively, convergence may be reached when centroid positions do not change after assigning the music objects to the nearest centroids and re-calculating the centroids. If convergence is not reached, the system 200 continues with Act 1206 , where the system 200 assigns each music object to the closest centroid associated with a group. In vector space diagram 1207 , as an example, no music objects change groups. Therefore, convergence will be reached after the next iteration and the process ends. In other example music object configurations, music objects may switch groups over several iterations. The system 200 may also use a stopping threshold to prevent the system 200 from boundless iterations. The system 200 may use a determined maximum number of iterations before terminating the process. Other expectation-maximization processes may use different steps or use different criterion for terminating the process.
[0077] FIG. 13 shows the acts the music object playback system takes to select and play a next music object. The acts illustrated in FIG. 13 may be implemented by the elements of system 300 , such as the processor 202 , the co-processor 203 , instructions or logic retained in the system memory 306 , the databases 308 , or retained in a computer-readable medium interfaced or coupled with the system 300 . After the music objects are organized based on the music object characteristic, as described in FIG. 11 , the system 300 may present a list of groups of music objects for the listener to select (Act 1302 ). The system 300 may present the list on the display 240 , the user interface 304 , or may output the list as an aural output on the speakers 380 . The system 300 may determine if the listener selects a group from the list of groups (Act 1304 ). The system 300 may receive listener input through the user interface 304 , such as through selectors 307 or other user input 309 . If the listener does not select a group, the system 300 may prompt the listener to select a group from which to play music objects (Act 1306 ). The system 300 may then present the list of groups again. In some systems, the system 300 randomly selects a group to play. In other systems, the system 300 may use a heuristic factor to select a group to play, such as a previously played group, a group that is rated by the listener, or from a playlist.
[0078] When the listener selects a group to play, the system 300 randomly selects a music object from the group for playback (Act 1308 ). The system 300 may play the music object over the speakers 380 . In some systems, the system 300 selects the music object to play based on a heuristic factor, such as a previously played group, a group that is rated by the listener, or from a playlist. The system 300 may then determine when the listener selects a next music object to play from the group (Act 1313 ). If the listener does not select a next music object to play, the system 300 may play the current music object until the end of the music object track (“EOT”) (Act 1312 ). In some systems, the system 300 prompts the listener to take an action to select the next music object.
[0079] When the listener selects a next music object to play, the listener is presented with at least four actions to select from (Block 1311 ). The listener may play the current music object to EOT (Act 1314 ). The listener may track to the next music object (Act 1316 ). The listener may select a next music object that is “more like,” or more similar, to the current playing music object (Act 1320 ). The listener may select a next music object that is “less like,” or less similar, to the current playing music object (Act 1324 ).
[0080] When the listener desires to play the current music object to EOT, or if the listener desires to track to the next music object, the system 300 randomly selects the next music object from within the group of music objects (Act 1318 ). As discussed above, the system 300 may also select the next music object based on a heuristic factor. When the listener desires to select a next music object that is “more like,” or more similar to the currently playing music object, the system 300 may determine the next music object by reducing the next music object selection space, such as by increasing a heuristic distance scaling factor associated with the group of music objects (Act 1322 ). When the listener desires to select a next music object that is “less like,” or less similar to the currently playing music object, the system 300 may determine the next music object by expanding the next music object selection space, such as by decreasing a heuristic distance scaling factor associated with the group of music objects (Act 1326 ).
[0081] The system 300 then may determine a uniform random variable (Act 1328 ). The system 300 may use a random number generator, a seed function, a look-up table, and/or other processes to determine a uniform random number. The system 300 may determine a maximum heuristic distance measure based on the uniform random number and the heuristic distance scaling factor (Act 1330 ). In some systems, the system 300 uses a square root function of the uniform random number and the heuristic distance scaling factor, such as by determining Eqn. 3 above. The system 300 may select the next music object to play using the maximum heuristic distance measure (Act 1332 ). For example, if the listener desires a next music object more similar to or “more like” the current music object, the maximum heuristic distance measure is less than for a desired next music object that is less similar to or “less like” the current music object. The next music object is more likely to be similar to the currently playing music object if the maximum heuristic distance measure is smaller than for a desired next music object less similar to the current music object. The maximum heuristic distance measure may also be adjusted to take into account ethnomusical preferences, such as maintaining the track order within a performance (e.g., track order in an opera). The system 300 may place the next logical track in an album closer in distance than other tracks. The system 300 may then continue with further actions selected by the listener from Block 1311 .
[0082] The music object organization system 200 may be adapted to process other types of object formats. The system 200 may be adapted to organize multimedia objects such as video or picture object formats, including WMV, MPEG, JPEG, GIF, BMP, AVI, TIFF, or other multimedia object formats. The multimedia object formats may be associated with an object characteristic that may be used to organize the objects heuristically. For example, video or picture objects may be associated with an object characteristic associated with events (e.g. vacation, birthday, graduation, sporting events, or other events), locations, time recorded, object content (e.g., museum exhibits, still life, action, people, animals, nature, or other content indicia), and/or other object characteristics. The system 200 may be adapted to organize the multimedia objects based on the object characteristics using the process described in FIG. 11 . The playback system 300 may also be adapted to present the multimedia objects using similar playback actions.
[0083] The systems 200 and 300 may also be adapted for other multimedia object content, such as entry objects in address books or phone books. Instead of a flat list, or a most recently called list, the system 200 may be adapted to group phone numbers together by how the user has statistically called them. Once enough statistics have been gathered, the system 200 may generate groups like “Friends,” “Work,” “Restaurants,” etc.
[0084] The methods shown in FIGS. 11-13 may be encoded in a signal-bearing medium, a computer-readable medium such as a memory, programmed within a device such as one or more integrated circuits, or processed by a controller or a computer. If the methods are performed by software, the software may reside in a memory resident to or interfaced to the music object organization system 200 , the music object playback system 300 , a communication interface, or any other type of non-volatile or volatile memory interfaced or resident to the system memory 204 or 304 . The memory may include executable instructions for implementing logical functions. Logic or a logical function may be implemented through digital circuitry, processor executable instructions, through analog circuitry, or through an analog source, such as through an analog electrical, audio, or video signal. Executable instructions may be embodied in any computer-readable or signal-bearing medium for use by, or in connection with an instruction executable system, apparatus, or device. Such a system may include a computer-based system, a processor-containing system, or another system that may selectively fetch instructions from an instruction executable system, apparatus, or device that may also execute instructions.
[0085] A “computer-readable medium,” “machine-readable medium,” “propagated-signal medium,” “product,” “computer program product,” and/or “signal-bearing medium” may comprise any means that contains, stores, communicates, propagates, or transports software for use by or in connection with an instruction executable system, apparatus, or device. The machine-readable medium may selectively be, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. A non-exhaustive list of examples of a machine-readable medium includes: an electrical connection having one or more wires, a portable magnetic or optical disk, a volatile memory such as a Random Access Memory “RAM” (electronic), a Read-Only Memory “ROM” (electronic), an Erasable Programmable Read-Only Memory (EPROM or Flash memory) (electronic), or an optical fiber (optical), and/or a signal that propagates through space or along an optical or electrical conductor. A machine-readable medium may also include a tangible medium upon which software is printed, as the software may be electronically stored as an image or in another format (e.g., through an optical scan), then compiled, and/or interpreted or otherwise processed. The processed medium may then be stored in a computer and/or machine memory.
[0086] While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents. | A multimedia organization and playback system intelligently organizes media objects, such as music files, and plays back their contents. The system considers and analyzes multiple media object attributes to determine groups of similar songs. As a result, the system delivers a consistent selection of media to the listener despite wide variations in media characteristics and without overburdening the listener with complicated configuration input. The listener may play back grouped songs based on the similarities between songs. Successive selections may be more or less similar to a current selection based on the organization of the music objects. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This patent application claims priority from PCT/GB03/05337, having an international filing date of 8 Dec. 2003, and a priority date of 9 Dec. 2002.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
Not Applicable
BACKGROUND OF THE INVENTION
The present invention relates to downhole tools for use in cased or lined well bores for the oil and gas industry, and in particular to a downhole tool which includes a barrier between the tool body and well bore wall which is actuable to control fluid flow past the tool.
It is considered desirable when drilling for oil or gas to maintain a clean interior in the casing or liner of the drilling well. For this purpose, well cleaning equipment is well known and comes in a variety of different forms, including casing scrapers, brushes and circulation tools. Such equipment is used to free the well tubing from debris particles, cement lumps, rocks, congealed mud and so on.
Indeed well clean-up apparatus is used in an attempt to clean the casing or other well tubing of even smaller particles or debris such as oxidation lumps, scale and burrs for example.
More advanced clean-up tools have also been developed which filter the well fluid downhole. This is done to remove the debris prior to production of the well. Such filtering tools generally operate by providing a barrier in the annulus between the tool body and the wall of the well casing or liner. The barrier causes diversion of fluid flowing past the tool into the tool. Once inside the tool the fluid is passed through a filter and then directed back into the annulus on the opposite side of the barrier. Such a tool is that disclosed in GB 2335687.
A major disadvantage of these tools is that, as filtering is required in one flow direction through the tool, a second flow path through the tool must be provided for fluid flow in the opposite direction so that the tool can be run in and/or pulled out of the well bore without re-dispersing the collected debris. This additional flow path restricts the volume of fluid which can pass the tool and may be prone to clogging if unfiltered well fluid is required to take this flow path on running in.
It is an object of the present invention to provide a downhole tool which allows for selective bypass of fluid around the outer body of the tool.
It is a further object of at least one embodiment of the present invention to provide a downhole tool with an actuable barrier which can be used to selectively divert fluid through the tool body.
It is a yet further object of at least one embodiment of the present invention to provide a downhole tool with an actuable barrier which can be used to selectively divert fluid passing the tool body through the tool body when the tool is run-in, pulled out or is stationary within the well bore.
BRIEF SUMMARY OF THE INVENTION
According to a first aspect of the present invention there is provided a downhole tool for use in a cased or lined well bore, the tool comprising a body connectable in a work string, a fluid flow path through the tool body and a barrier located at an outer surface of the tool, wherein the barrier is actuable to control fluid flow passing the tool and selectively divert fluid flow through the flow path.
When the barrier is not actuated the tool allows fluid flow to run unimpeded in the annulus between the tool body and the wall of the well bore. Conversely, the barrier may be actuated to cause passage of fluid through the tool.
Preferably the barrier comprises a resilient member which when acted upon by actuating means deforms to extend the member towards a wall of the well bore. The resilient member may be a rubber ball. Alternatively the resilient member may be an inflatable bladder.
Advantageously the barrier includes a surface engageable with the well casing or liner. The surface may provide a seal such that fluid is substantially restricted from passing the tool. Thus the barrier is circumferentially arranged on the outer surface of the tool body. Further the barrier may be rotatable with respect to the tool body. Advantageously also the surface is a wiper so that as the tool is moved within the well bore the casing or liner is cleaned when the surface is engaged.
Preferably the actuating means is a hydraulic actuator. Hydraulic fluid may flow directly against the resilient member to cause deformation. Alternatively the fluid may act upon a piston member, wherein movement of the piston member causes the resilient member to deform. In a first embodiment the resilient member may be initially held in compression by a retainer and the piston member releases the retainer.
Advantageously, well fluid within the well bore may be the hydraulic fluid to operate the actuating means.
Alternatively the actuating means may include a ball valve. Thus the barrier may become actuable through a drop ball released at the surface and carried through a bore in the work string. To selectively actuate the barrier the drop ball may be deformable as are known in the art. This is as disclosed in WO02/061236 for example.
The work string may be a pipe string, coiled tubing or a wireline.
Preferably the tool includes an axial bore for fluid circulation through the work string. Preferably also the tool body is substantially cylindrical to provide the annulus between the tool and the wall of the well bore.
There may be a plurality of fluid flow paths through the tool body. One or more of the fluid flow paths may include a filter so that well fluid can be filtered downhole. Alternatively the fluid flow path may form a hydraulic line for the actuation of a feature of the downhole tool. Preferably the fluid flow path has an inlet and an outlet. Preferably the inlet and outlet are each arranged on an outer surface of the tool. Preferably also the inlet and outlet are arranged on either side of the barrier.
According to a second aspect of the present invention there is provided a downhole tool for collecting loose debris particles within a well bore, the tool comprising a body connectable in a work string, a fluid flow path through the tool body including means for filtering debris particles and a barrier located at an outer surface of the tool, wherein the barrier is actuable to control fluid flow passing the tool and selectively divert fluid flow through the flow path.
The filtration means may be a wire screen sized to prevent particles of a predetermined size from passing therethrough. It will be appreciated however that many different types of filtration apparatus may be used, including permeable textiles, holed tubes or cages, and so on. The filtration means need not be limited to any one particular type of screen or filter, but may rather comprise of a plurality of filters in series; the filters being potentially of varying type and permeability.
The tool may also act as a collector or trap for debris and the like. For example, a trap may be provided on the up-stream side of the filter means for storing the filtered debris.
Optionally, a separate filter may be provided for each filtered flow path.
Preferably the barrier comprises a resilient member which when acted upon by actuating means deforms to extend the member towards a wall of the well bore. The resilient member may be a rubber ball. Alternatively the resilient member may be an inflatable bladder.
Advantageously the barrier includes a surface engageable with the well casing or liner. The surface may provide a seal such that fluid is substantially restricted from passing the tool. Thus the barrier is circumferentially arranged on the outer surface of the tool body. Further the barrier may be rotatable with respect to the tool body. Advantageously also the surface is a wiper so that as the tool is moved within the well bore the casing or liner is cleaned when the surface is engaged.
Preferably the actuating means is a hydraulic actuator. Hydraulic fluid may flow directly against the resilient member to cause deformation. Alternatively the fluid may act upon a piston member, wherein movement of the piston member causes the resilient member to deform. In a first embodiment the resilient member may be initially held in compression by a retainer and the piston member releases the retainer.
Advantageously, well fluid within the well bore may be the hydraulic fluid to operate the actuating means.
Alternatively the actuating means may include a ball valve. Thus the barrier may become actuable through a drop ball released at the surface and carried through a bore in the work string. To selectively actuate the barrier the drop ball may be deformable as are known in the art. This is as disclosed in WO02/061236.
The work string may be a pipe string, coiled tubing or a wireline.
Preferably the tool includes an axial bore for fluid circulation through the work string. Preferably also the tool body is substantially cylindrical to provide the annulus between the tool and the wall of the well bore.
There may be a plurality of fluid flow paths through the tool body. Preferably the/each fluid flow path has an inlet and an outlet. Preferably the inlet and outlet are each arranged on an outer surface of the tool. Preferably also the inlet and outlet are arranged on either side of the barrier.
According to a third aspect of the present invention there is provided a method of controlling fluid flow in a well bore, comprising the steps:
(a) running a tool having an actuable barrier on a work string downhole; (b) creating relative movement between the fluid in the well bore and the tool; (c) actuating the barrier to control fluid flow passing the tool by varying the cross sectional area of the annulus between the tool and the wall of the well bore.
The method may further include the step of selectively diverting fluid flow through a flow path in the tool.
Preferably the method may include the step of actuating the barrier until the barrier sealingly engages the wall of the well bore and thus substantially restricts fluid flow passing the tool.
Additionally the method may include the step of filtering the fluid flow through the flow path in the tool.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings of which:
FIG. 1 is a part cross-sectional view through a downhole tool according to a first embodiment of the present invention;
FIG. 2 is a part cross-sectional view through a downhole tool according to a second embodiment of the present invention; and
FIG. 3 is a part cross-sectional view through a downhole tool according to a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference is initially made to FIG. 1 of the drawings, which illustrates a downhole tool, generally indicated by reference numeral 10 , according to a first embodiment of the present invention. Tool 10 comprises a generally cylindrical body 12 having an axial bore 14 therethrough. At an upper end 16 of the tool 10 there is provided a box section (not shown) and at the lower end 18 of the tool 10 there is a pin section (not shown), as are known in the art, for connecting the tool 10 to a work string (not shown).
Around an inner mandrel 11 of the body 12 there is located a sleeve 20 . Sleeve 20 provides an inlet port 22 of annular shape at the upper end 16 of the tool 10 . At the lower end 18 is arranged a stop surface 24 to join the sleeve 20 to the mandrel 11 . In a portion of the wall 26 of the sleeve 20 , towards the lower end 18 , there is a filter 28 . Filter 28 is a cylindrical screen which can filter loose debris and particles from fluid passing through it. Together the sleeve 20 with filter 28 and stop 24 provide a trap 30 where debris will collect when fluid flow is in a direction marked by arrows A.
Between the mandrel 11 and the sleeve 20 are located ports 32 . Although a single port 32 is shown, typically there will be a number of ports symmetrically arranged around the mandrel 11 . However sufficient space around the ports 32 is provided for the entry of larger pieces of debris to the trap 30 . Mounted at an outlet 34 of the port 32 is an inflatable seal 36 . Seal 36 is circumferentially arranged around the sleeve 20 . Seal 36 is made of a resilient rubber which when inflated from the inside will increase the size of the seal to fill the annular space 38 between the tool 10 and the casing/liner wall 40 of the well bore 42 . When deflated the seal 36 is afforded some protection by a lip 43 on sleeve 20 which directs fluid toward the casing 40 .
Within the mandrel is located a ball valve, generally indicated by reference numeral 44 . Valve 44 comprises a seat 46 which is initially held to the mandrel 11 by a shear pin 48 . A stop 50 is also provided on the mandrel 11 .
In use, tool 10 is run in well bore 42 through casing 40 on a work string (not shown). As shown on the left hand side of FIG. 1 , the seal 36 is initially deflated so fluid can flow upstream or downstream of the tool shown by arrows B. This provides a large circulation path for the fluid. Fluid can also flow through the axial bore 14 independently. Valve seat 46 is located across the port (s) 32 to prevent the seal inflating. The valve seat is held in position by the shear pin 48 .
When fluid is required to be filtered, such as on pulling out the tool 10 from the well bore 42 , a ball 52 is dropped from the surface into the axial bore 14 . Ball 52 travels under fluid pressure to the seat 46 where it blocks the passage of fluid through the bore 14 . Pressure then builds up behind the ball, sufficient to shear the pin 48 and move the seat 46 downwards. The seat 46 will fall to the stop 50 , whereupon fluid within the bore can now flow through port 32 to outlet 34 and fill the seal 36 . Seal 36 consequently expands by inflation to fill the annulus 38 and prevent fluid flow down the outside of the tool 10 between the sleeve 20 and the casing 40 . The fluid flow to the seal 36 is regulated by a check valve 54 located in the port 32 to prevent over inflation of the seal 36 .
Seal 36 now engages the casing 40 , as shown in the right hand side of FIG. 1 . Seal 36 has a surface which is suitable for continuous contact to the casing 40 while the tool is moved within the casing 40 . This surface is typically a roughened rubber surface such as knobbles which reduce the surface contact area without reducing the quantity of fluid flow passed the tool 10 . When tool 10 is moved, fluid is now directed into the annular port 22 and travels into the trap 30 . The fluid is filtered by passing through filter 28 and the clean fluid exits the tool below the seal 36 . Any debris filtered from the fluid is caught within the sleeve 20 and falls against stop 24 or is held in filter 28 . Trap 30 can be emptied when the tool 10 is removed from the well bore 42 .
If filtering is not required at any time, that is if the tool is to be further plunged into the well, fluid pressure is increased through the axial bore 14 . As valve 54 is closed, the increased pressure acts upon the drop ball 52 . Drop ball 52 is deformable and thus will be extruded through the seat 46 and fall through the axial bore 14 . A ball catcher can be located further down the work string to retrieve the ball 52 . When extruded the pressure drop in the bore 14 causes the check valve 54 to open and fluid is released from the seal 36 . Seal 36 then deflates, just before spring 56 returns the valve seat 46 back over the port 32 . The tool 10 is thus reset and seal 36 can be actuated as often as required by repeating the process.
Reference is now made to FIG. 2 of the drawings which illustrates a downhole tool, generally indicated by reference numeral 210 , according to a second embodiment of the present invention. Like parts to those of FIG. 1 have been given the same reference numeral with the addition of 200 . The filter and trap arrangement are included in the tool but are omitted from the Figure to provide better clarity to the sealing arrangement.
In this second embodiment the valve seat 246 extends through the sleeve 220 to provide a retainer cup 70 in the annulus. Engaging slots are provided between the sleeve 220 and the cup 70 to prevent a fluid path being provided at this position on the tool.
Initially the retainer cup 70 retains a rubber ring 72 against the sleeve 220 to provide the passage past the tool. On dropping the ball 252 , to a similar ball valve arrangement, the cup 70 is moved downwards and the ring expands to fill the annulus 38 . The tool 210 can then operate in an identical manner to the tool 10 of FIG. 1 .
Reference is now made to FIG. 3 of the drawings which illustrates a downhole tool, generally indicated by reference numeral 310 , according to a third embodiment of the present invention. Like parts to those of FIG. 1 have been given the same reference numeral with the addition of 300 .
In likeness to the previous example embodiment, the barrier in the embodiment of FIG. 3 is a rubber ring 372 . The ring 372 is shown in a non-actuated position in the left hand section of the drawing, where it is compressed against sleeve 320 by a drag block 370 . The drag block 370 is sufficiently slotted or ported so as to enable fluid to flow through it, yet nevertheless it is also adapted to undergo movement when drag forces resulting from a predetermined flow of fluid act on it. Thus in use, fluid can flow over the outside of the tool, by the route of arrow B. Here the ring 372 is compressed and held in position by the drag block 370 . When fluid pressure is increased by a predetermined amount or, alternatively, the tool is pulled from the well bore, an increase in pressure will occur on the surface 374 of each drag block 370 . Drag block 370 will then move relative to the tool 310 and the ring 372 will be released to expand and fill the annulus 38 , thereby redirecting fluid flow through the tool in the direction of arrow A. The advantage of this embodiment is that the barrier is actuated by the well fluid and a second actuating fluid is not required.
The principal advantage of the present invention is that it provides a downhole tool wherein fluid passing the tool can be selectively diverted through the tool.
A further advantage of the present invention is that it provides a downhole tool wherein fluid can be filtered within a well bore when the tool is run in or pulled out of the well bore.
It will be appreciated by those skilled in the art that further modifications could be made to the invention herein described without departing from the scope thereof. For instance the ball valve could be released by inserting a smaller steel ball to block the port 32 to allow pressure to build up on the deformable ball 52 . | A downhole tool for use in a cased or lined well bore ( 40 ), the tool including a barrier ( 36 ) arranged on an outer surface of the tool. The barrier may be of a resilient material so that it can be deformed on actuation to control the passage of fluid between the tool and the casing or liner. Fluid flow is thus selectively diverted through flow paths ( 22 ) in the tool. Embodiments are described for actuating the barrier by hydraulic means and for filtering the fluid within the flow paths. | 4 |
RELATED APPLICATIONS
This patent application is a continuation application of patent application Ser. No. 11/171,452, filed Jul. 1, 2005, which is incorporated by reference herein.
TECHNICAL FIELD
The present invention relates generally to the creation of passwords. More particularly, embodiments of the present invention relate to assisting in the creation of strong passwords.
BACKGROUND
In modern computer systems, authentication techniques, such as passwords, have become very important. However, password guessing and cracking tools have also become more capable. If someone is able to guess or hack a user's password, then they may be able to gain access to sensitive information, such as personal identity information or financial information. Therefore, it is generally recommended to use strong (or complex) passwords.
A strong password typically is a certain length and may contain characters of various types. There are many types of requirements for creating strong passwords. For example, a password may be required to be at least seven characters long, contain letters, contain numerals, and contain one or more symbols. In addition, a password may be required to be significantly different from previous passwords, not contain a name, and not be a common word or name. Known systems can provide a dialog window or list of rules through a graphical user interface to indicate the minimum requirements for entering a password.
Unfortunately, users are reluctant to create strong passwords because they can be difficult to remember or create. Instead, users tend to create passwords that are based primarily on a common word, or name. Even when users attempt to create a strong password, they often structure the password so that it is easily memorable. For example, if a user is required to create a password that is seven characters long and includes at least one number. Many users will merely create a password that contains six letters and one number, such as “password1.” Although stronger than a plain password, such passwords are still easily guessed.
In addition, known methods and systems often require a user to make multiple attempts at entering a password before they are able to satisfy all the applicable rules. This can be a tedious and frustrating experience for the users.
Accordingly, it may be desirable to provide methods and systems that assist users in the entry of strong passwords.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention. In the figures:
FIG. 1 illustrates a system that is consistent with the principles of the present invention;
FIG. 2 illustrates a server that is consistent with the present invention;
FIG. 3 illustrates an exemplary architecture for a server that is consistent with the present invention;
FIG. 4 illustrates an exemplary process flow that is consistent with the present invention; and
FIG. 5 shows an exemplary display screen that is consistent with the present invention.
DETAILED DESCRIPTION
Embodiments of the present invention assist users with the entry of strong passwords. The password may be considered strong if it satisfies one or more requirements, such as a minimum character length. A set of these requirements may be selected and then presented to the user. The requirements may be randomly selected individually or as a group. The requirements may also be presented to the user one by one in a random order or in the form of a list with a random order. As characters for the password are entered, the user may then be notified when one or more the requirements have been satisfied.
Reference will now be made in detail to exemplary embodiments of the invention, which are illustrated in the accompanying drawings. FIGS. 1-3 illustrate various systems and components that may be used to implement embodiments of the present invention. FIGS. 4-5 illustrate a process flow and display screen that is consistent with the principles of the present invention. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
FIG. 1 illustrates a system 100 that is consistent with the principles of the present invention. For purposes of illustration, system 100 is shown as a typical system implemented in a network environment, such as the Internet. One skilled in the art will recognize that there many applications on the Internet that may use authentication techniques, such as a password.
As shown, system 100 may comprise a client 102 and a server 104 . These components may be coupled together via network 106 . Network 106 may comprise one or more networks, such as a local area network, or wide area network. In addition, network 106 may support a wide variety of known protocols, such as the transport control protocol and Internet protocol (“TCP/IP”) and hypertext transport protocol (“HTTP”).
The components of system 100 may be implemented on separate devices or may be implemented on one or more of the same devices or systems. For example, system 100 may have one or more of its components implemented on multiple machines that run different operating systems. Some of the specific components of system 100 will now be described.
Client 102 provides a user interface for system 100 . Client 102 may be implemented using a variety of devices and software. For example client 102 may be implemented on a personal computer, workstation, or terminal. In addition, client 102 may run under an operating system, such as the LINUX operating system, the Microsoft™ Windows operating system, and the like. Client 102 may also operate through an Internet browser application, such as Firefox by Mozilla, Internet Explorer by Microsoft Corporation, or Netscape Navigator by Netscape Communications Corporation. One skilled in the art will also recognize that client 102 may be implemented with various peripheral devices, such as a display, one or more speakers, and other suitable devices that are capable of providing feedback information to a user. Client 102 may also be implemented with various peripherals for accepting input from a user, such as a keyboard, a mouse, and the like. Although FIG. 1 shows a single client, system 100 may include any number of clients.
Server 104 stores, manages, and provides access control to items requested by client 102 . For example, server 104 may process requests to retrieve an object, document, image file, web page, and the like. Server 104 may be implemented using a variety of devices and software. For example, server 104 may be a computer that runs one or more application programs and stored procedures under an operating system, such as LINUX, Windows, or Solaris.
FIG. 2 illustrates a server that is consistent with the present invention. As shown, server 104 may include a central processor 200 , a cache 202 , a main memory 204 , a local storage device 206 , and an input/output controller 208 . These components may be implemented based on hardware and software that is well known to those skilled in the art.
Processor 200 may include cache 202 for storing frequently accessed information. Cache 202 may be an “on-chip” cache or external cache. Server 104 may also be provided with additional peripheral devices, such as a keyboard, mouse, or printer (not shown). In the embodiment shown, the various components of server 104 communicate through a system bus 210 or similar architecture.
Although FIG. 2 illustrates one example of the structure of server 104 , the principles of the present invention are applicable to other types of processors and systems. For example, server 104 may comprise multiple processors, such as those provided by the Intel Corporation, or may comprise multiple computers that are linked together.
FIG. 3 illustrates an exemplary functional architecture for server 104 that is consistent with the present invention. As shown, server 104 may include an operating system (“OS”) 300 , a user interface 302 , a password manager 304 , and a password database 306 . These components may be implemented as software, firmware, or some combination of both, which may be loaded into memory 204 of server 104 . The software components may be written in a variety of programming languages, such as C, C++, Java, etc.
OS 300 is an integrated collection of routines that service the sequencing and processing of programs and applications by server 104 . OS 300 may provide many services, such as resource allocation, scheduling, input/output control, and data management. OS 300 may be predominantly software, but may also comprise partial or complete hardware implementations and firmware. Well known examples of operating systems that are consistent with the principles of the present invention include Mac OS by Apple Computer, Open VMS, GNU/LINUX, AIX by IBM, Java and Sun Solaris by Sun Microsystems, and the Windows family of operating systems by Microsoft Corporation.
Interface 302 provides a communications interface between server 104 and client 102 . For example, interface 302 may be configured to provide information that indicates the status of a proposed password that is being entered at client 106 . Such communications may be based on well known protocols and programming languages, such as TCP/IP and Java. Interfaces like interface 302 may be implemented using well known Internet technologies, such as web pages, which are well known to those skilled in the art.
Password manager 304 provides the logic for analyzing and managing the passwords proposed at client 106 . For example, password manager 304 may be configured to randomly retrieve one or more rules for a password, provide information that indicates these rules, and determine the status of a proposed password. As noted, password manager 304 may be written in a variety of programming languages, such as C, C++, Java, etc. and executed by server 104 . In other embodiments, one or more of the functions of password manager 304 may be implemented as program code running on client 102 .
Password database 306 provides storage and retrieval for the password data and the various rules that govern passwords. Password database 306 may be implemented using well known database technology, such as relational databases, or object oriented databases.
One skilled in the art will recognize that FIGS. 1-3 merely illustrate some embodiments of the present invention. For example, embodiments of the present invention may be implemented as software that is installed on a single computer. In other embodiments, server 104 may be configured as a central password authority to ensure that all clients, such as client 102 , adhere to the same password rules.
Reference will now be made to FIGS. 4-5 to illustrate an exemplary process and display that are consistent with the present invention. As noted, the process and display illustrated in FIGS. 4-5 may be implemented using client 102 , a programmed computer or other processing device. The program code may be stored on a storage medium, such as a compact disk, diskette, or any other suitable storage medium.
FIG. 4 illustrates a process flow for entering a strong password. In stage 400 , one or more requirements for the password are randomly selected and provided. Password manager 304 may be triggered to begin its operations based on a number of events. For example, password manager 304 may be triggered in response to a request from client 102 . Alternatively, password manager 304 may be triggered based on a time interval. For example, password manager 304 may be configured to require a new password at least once a month or once a year.
Password manager 304 may select one or more rules from password database 306 in various ways. For example, password database 306 may contain a large number of available rules for governing passwords and each rule may be assigned a unique identifier. Password manager 304 may then retrieve one or more of these rules from password database 306 by selecting the appropriate unique identifiers. In some embodiments, password manager 304 may select a rule randomly one at a time. That is, password manager 304 may select each rule independently of each other. Alternatively, password manager 304 may randomly select a group of rules. For example, password manager 304 may be configured to support multiple types or classes of users such that some users may require higher levels of security. Accordingly, password manager 304 may retrieve and randomly select different groups of password rules for different classes of users.
Generally, password manager 304 may assist users in creating strong passwords by guiding the users in entering “random” characters for the password. In order to accomplish this, password manager 304 may be configured to provide its rules for a password in a random sequence either individually or in a group. For example, if a particular password is required to contain at least one capital letter and at least one numerical character, password manager 304 may provide these rules to the user in a random order. Otherwise, the user may be tempted to simply enter a password with a capital letter followed by a number as part of the password. However, if the user is randomly prompted first to enter a number and then a capital letter, the user is likely to respond in kind and enter the characters in a fashion that mimics the random order, which may eventually lead to a stronger password.
In addition, password manager 304 may also be configured to provide various rules for when users are changing from a previous password. For example, password manager 304 may randomly select one or more rules that specify the extent to which a new password must differ from a previous password.
Once it has selected the applicable rules, password manager 304 may provide the rules to client 102 , for example, via interface 302 . Password manager 304 may provide the applicable rules in the form of text or other type of information, such as extensible markup language data. Subsequently, client 102 may then provide the applicable password rules to the user. For example, client 102 may provide the password rules using a dialog window or other suitable graphical user interface. In order to assist the user, client 102 may display the rules one at a time or in the form of a list.
In stage 402 , characters for the password are received and it is determined whether the characters satisfy the requirements. In particular, a user at client 102 may commence entering characters for a proposed password. Client 102 may then analyze these characters to determine if they satisfy the rules received from password manager 302 . Client 102 may be configured to continuously analyze the entered characters one at a time or in sets. For example, client 102 may be configured to buffer a number of characters and then analyze whether this group of characters assists in satisfying one or more rules. The number of characters buffered may be configured by client 102 or may be directed by password manager 302 .
In some embodiments, client 102 continuously evaluates the characters as they are entered by the user against the applicable password rules. Client 102 may perform this analysis alone or in conjunction with server 104 . For example, when a user enters a character, client 102 may determine if a selected rule has been satisfied in real time.
In stage 404 , as the user enters characters for the password, client 102 may provide feedback to the user regarding the status of satisfying the password rules. For example, client 102 may highlight a rule or display a visual indicator, such as a check mark or “X”, to indicate that the recently entered character was sufficient to satisfy one or more rules. Conversely, client 102 may provide feedback when the characters entered fail to satisfy one or more rules. Client 102 may also provide other forms of feedback, such as an audible tone, to the user as characters are entered for a password.
Accordingly, client 102 may be configured to provide effective feedback to the user as to the status of their proposed password. Client 102 may continuously provide the feedback visually or audibly, for example, after each character has been entered.
In some embodiments, the user may then confirm that their proposed password satisfies all of the rules provided. For example, client 102 may provide a dialog window with a button that the user selects to confirm they have completed entering a proposed password. Client 102 may then perform a final analysis of the entered password. This analysis may be performed by client 102 alone or in conjunction with server 104 .
FIG. 5 shows an exemplary display screen that is consistent with the present invention. As shown, check marks are displayed next to various rules as the user has entered characters for a password. In the example shown, the rules have been selected and displayed in a random order (from top to bottom) to assist the user. Of course, one skilled in the art will recognize that other types of displays and windows may be used in embodiments of the present invention.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only. | A processor executing a password manager randomly selects a first requirement and a second requirement for creating a password from a set of requirements, wherein the second requirement is selected independently of the first requirement. The processor provides the first requirement for creating the password, receives characters for the password, determines whether the characters satisfy the first requirement, and provides information that indicates whether the characters satisfy the first requirement. Responsive to the characters satisfying the first requirement, the processor provides the second requirement for creating the password. | 6 |
CROSS REFERENCES TO RELATED APPLICATIONS
This application is a continuation of the following application, U.S. patent application Ser. No. 10/626,476, filed on Jul. 23, 2003, which is hereby incorporated by reference, as if it is set forth in full in this specification:
BACKGROUND OF THE INVENTION
This invention relates in general to a system for automated control and more specifically to a system for monitoring and managing crop growth.
Agriculture has been an important aspect of human existence for many years. Improvements in caring for crops, accelerating crop growth, ensuring the quality of crops and providing for a plentiful and efficient harvest have continued to contribute to the enjoyment and improvement of our population's quality of life.
Important areas for automation of agriculture include irrigation, protection against weather, insects and disease, and providing for plant nutrition. Also, it is important to be able to forecast crop growth and harvests so that the economics of harvesting and distribution can be more efficient.
One example of a type of crop that has benefited greatly from recent trends in automated agriculture is the grape which bears fruit used to make wine. Today's vineyards include different dispensing systems for providing water to crops for irrigation. Examples of such systems are “drip” or “sprinkler” systems where water is routed among rows of vines by a tube having emitting holes spaced at regular intervals. The water flow can be turned on or off manually, or can be automated with a timer control, computer, etc. The tubes can be elevated above the ground, or at or below ground level.
While such irrigation systems have proven effective, they do not provide a high level of automation. For example, care must be taken to provide the proper amount of water over time to the crops. Also, it is difficult to selectively provide different amounts of water to different plants, or even plant rows or areas. Some growers rely on many sources of sophisticated information to decide on the times and amounts of irrigation. The plant sizes, weather conditions and forecasts, soil conditions, etc., must be taken into account. The analysis can be performed by each grower, independently, or can be provided by a service to which growers subscribe to help each grower determine how to irrigate. Although, such systems often do achieve improved irrigation, the irrigation process, overall, requires much human participation and is prone to errors and inefficiencies. For example, just measuring the amount of water dispensed to vines is difficult. Although the amount of water injected into the system is easily obtained, it is usually unknown how much water is actually provided to the vines' roots.
Fertilizers and insecticides are typically applied with the use of machinery such as spraying machines and tractors. The application of these chemicals is both vital and complicated. Machine spraying of chemicals requires human action and judgment. Further, application of the chemicals at the wrong time, or under the wrong conditions, can result in violation of laws, ineffective application, crop loss, increased expenses, etc. Growers must be aware of weather and wind conditions so that certain chemicals do not become dispersed to neighboring properties and so that the chemicals have their intended effect on the crop being treated. Many chemicals are restricted and their use must be closely monitored to comply with regulations. The application of chemicals is very labor-intensive and expensive not only in terms of human labor but also for the chemicals, themselves, application methods, fuel used by equipment, etc.
Some rudimentary chemical dispensing systems exist that are similar to the tube irrigation systems. However, a tube dispensing system can not efficiently handle all of the different chemicals that need to be applied. This is because some of the chemicals can not be mixed with others so it is necessary to flush the system with water between application of different chemicals. As with water irrigation, it is difficult to determine how much chemical (or other material) is being dispensed to each vine, row, or even section of vineyard. Further, extensive monitoring, forecasting and other information must be obtained to perform an analysis and determine the proper time to apply an insecticide, fungicide, nutrient, etc. Often, today's growers irrigate and apply chemicals without sufficient regard to available weather data, soil moisture status, statistics, analysis and other crucial data. This can result in crop failure, lower quality crops, or inefficiencies in growing and harvesting that lead to lower profits and the inability to increase subsequent crop quality and/or yields.
For example, the majority of fungicide applications are made based on temperature and humidity information obtained and applied in a rudimentary manner by the vineyard operator, or by basic visual inspections of the vineyard on a semi-frequent basis. This technique of scouting or tracking basic weather data is generally sufficient, however, it can and often does, lead to late application of products after disease is present in the vineyard.
Once disease is present, there is less time available for the grower to get protective fungicides applied and there is generally always a resulting decrease in quality of the grapes in the affected areas. Fungicides are applied by the grower to the affected areas by way of tractor mounted or pulled spray equipment which directs fungicide sprays at the vines. Depending on how quickly the disease is progressing, and how quickly the grower can make an application to all the affected areas, the results can be quite devastating to both yield and quality. It can also have a significant affect on the maturation process of the grapes which has an impact on the final quality as well.
The current methods of applying fungicides and insecticides rely on the use of tractor or trailer mounted application equipment. The spray is directed at the canopy and the coverage is limited by the water volume used. The volume used is regulated by the pressure of the spray pump and the speed that the tractor moves through the vineyard. There is a tradeoff between coverage based on water volume and timing to cover the acres to be sprayed. The more water that is used, the better the coverage but the slower the tractor moves through the vineyard. Therefore, when better coverage is desired, it takes longer to make the necessary applications. This increases the cost to the grower and creates more potential for disease development before protective fungicides can be applied. It also increases exposure to the applicators as they spend more time in the vineyard while making the application. This method of application relies on the availability of tractors in good working order to make the applications. This requires the grower to keep equipment in good working order at all times and increases risk based on breakdowns of equipment during critical application timings.
Currently, the cost of making an application of fungicides, insecticides, nutrients, etc., actually exceeds the cost of the product being applied. Growers seek to reduce their cost of applications and to ensure that applications are made efficiently, effectively, only when necessary, at the proper time and to the exact extent necessary.
Thus, it is desirable to provide a system that improves upon one or more of the shortcomings of the prior art.
SUMMARY OF THE INVENTION
The invention provides a comprehensive system for automating the growing of crops, such as grapevines. Combinations of data from sensors local to a vineyard, and from optional remote stations and sensors, is combined with a control system to accurately control the dispensing of water and chemicals such as insecticides, disease prevention materials and fertilizers.
The materials are dispensed through a multiple channel conduit which allows conflicting, or incompatible, types of materials to be transported through a common assembly. Sensors are attached to the conduit so that the placement of sensors can occur simultaneously with the laying of the conduit. This approach also ensures correct placement and spacing of the sensors with respect to each plant, or plant area, to be monitored.
In one embodiment the invention provides a conduit for dispensing two or more different liquid types to crops. The conduit includes a first channel for conveying a first liquid type; a second channel for conveying a second liquid type; and a plurality of outlets spaced at intervals for dispensing both the first and second liquid types, wherein each outlet is used to dispense both the first and second liquid types.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the system of the present invention;
FIG. 2A illustrates a cut-away view of a conduit;
FIG. 2B shows a cutaway view of the conduit of FIG. 2A ;
FIG. 2C shows a common-capillary arrangement;
FIG. 3 shows details of the system of FIG. 1 ;
FIG. 4A is a first drawing of different types of sensors; and
FIG. 4B is a second drawing of different types of sensors.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates the system of the present invention. A preferred embodiment of the system is referred to as the “Chemical on Demand” system manufactured and marketed by Terra Spase, Inc.
In FIG. 1 , system 100 is used to deliver materials such as chemicals 102 , 104 and 106 ; and water 108 to crops 110 via conduit 120 . Examples of chemicals for delivery are fertilizer, insecticides, disease prevention fungicides or other treatments, etc. For purposes of illustration, the invention will be presented in a vineyard application. However, it should be apparent that aspects of the invention can be applied to many different crops, plants and other scenarios.
Each grapevine plant is illustrated as a circle such as vines 130 , 132 , 134 and 136 . Vines are organized into rows such as row 140 , 142 and 144 . Naturally, there can be any number of vines in a row and any number of rows. Although modern vineyards follow this row and grid pattern, the present invention can be adapted for use with any regular, ordered arrangement of plants. Also, aspects of the invention can be used on a small scale even where the layout of a vineyard, field, garden, etc., is not regular, ordered or is otherwise not uniform. However, consistent spacing of plants and rows has advantages in the manufacture, deployment and operation of conduit emitters and sensors, as discussed, below.
Conduit 120 houses multiple inner channels (not shown). In a preferred embodiment, there are enough channels to handle dispensing of each of the different materials (i.e., chemicals and water, as shown, although other embodiments can use any number of different materials). Particularly, where two materials are incompatible with each other, such as calcium and phosphorus solutions, then it is advantageous to maintain each solution in a separate channel of the conduit so that a shared channel will not have to be cleansed, or flushed, before using a different incompatible solution. A preferred embodiment of the invention uses four channels plus the conduit cavity to convey water, fungicides, insecticides, fertilizers, and other materials, as desired. Since different applications will require different numbers of materials, conduits can be manufactured with appropriate numbers of channels, channel sizes, etc., as discussed below.
FIG. 1 shows outlets, or emitters, from the conduit and channels as black dots such as emitters 150 , 152 , 154 and 156 . Each emitter can emit any of the materials transferred through channels in the conduit. Each emitter is present at a regularly spaced interval on the conduit in accordance with the spacing of the vines, as desired. Typical vine spacing is between 36″ and 96″. As is known in the art, the materials can be dispensed either above the plants, overhead, on the ground or even below the ground. The materials, if in liquid form, can be sprayed in addition to being dripped. A preferred embodiment of the invention uses under vine canopy drippers for nutrient and irrigation dispensing and uses above vine spraying with sprinklers or misters for fungicide and insecticide dispensing as well as water for cooling. The conduit housing the channels is suspended from the existing trellis in the vineyard that is used to support the growing grapevines. Other embodiments can allow the conduit to be placed on the ground, e.g., near the base of the vines; or even to be buried below ground.
Sensors 160 , 162 , 164 and 166 are attached to the conduit at regular intervals in accordance with the spacing of the vines. In FIG. 1 , sensors 160 , 162 , 164 and 166 are photodetectors for measuring sunlight which passes through the grape leaves. The larger the vine canopy, the less sunlight will fall on the photodetectors. Thus, a measure of the vines' growth is indicated by the cumulative signals of the photodetectors. Other types of sensors can be employed such as leaf wetness detectors, temperature, insect indicators (e.g., protein and DNA sensors), etc. Different types of sensors can be used at the same point or at different points. Since the sensors are attached to the conduit at regular intervals corresponding to the vineyard layout, the deployment of the sensors is very simple. Also, the regularity of the sensors with respect to the vineyard layout produces more interpretable results.
Materials are dispensed under control of control system 200 and flow control 202 . In a preferred embodiment control system 200 is a computer such as a personal computer, server, etc. However, any type of control system can be used such as a smaller digital system, analog system, mechanical, etc. Flow control 202 includes valves and flow monitors for letting a predetermined amount of any of the chemicals or water enter the conduit channels under control of control system 200 .
The output signals from sensors is received by sensing unit 204 and relayed to control system 200 . Sensing unit 204 can be, for example, a transducer for converting an analog signal to a digital signal. If the sensors, themselves, are outputting digital information then sensing unit 204 can act to multiplex, buffer, or otherwise manipulate or pre-process the data before sending the data to control system 200 . In some embodiments, sensing unit 204 may not be necessary.
External data is received by control system 200 via external data sources 206 . Such data sources can include information from local networks or wide area networks such as the Internet. Examples of external data include weather data, crop growth models, growing degree days, ET o and ET c (evapotranspiration coefficients), degree day insect models, disease risk models, irrigation requirements, crop nutrition requirements, crop development data, etc. The external data can come from a remote station, sensor, agency, or other source. The external data can also be generated by software (e.g., modeling, forecasting or analysis programs) that is located locally to the control system or which is remote from the control system. External data can be entered manually by the user or operator of the control system, or can be received automatically by the control system via a communication link or network such as the Internet. In general, data processing and acquisition can be performed in any geographic location and used in any manner known in the art to facilitate the operation of the system of the present invention.
Sensor data can be used in sophisticated analysis to control irrigation and application of other chemicals or materials. For example, the system can control application of materials according to methods described in academic papers such as IRRIGATION OF THOMPSON SEEDLESS TABLE GRAPES: UTILIZATION OF CROP COEFFICIENTS DEVELOPED AT THE KEARNEY CENTER FOR USE AT OTHER LOCATIONS IN THE SAN JOAQUIN VALLEY, by Larry E. Williams, Don Luvisi and Michael Costello; published in Viticulture Research Report Volume XXVII, 1998-99, California Table Grape Commission, Fresno, CA93711 which is hereby incorporated by reference as if set forth in full in this document for all purposes. Publicly available data such as at http://www.ipm.ucdavis.edu/, etc., can be used to provide rules and guidelines for controlling material dispensing according to the system of the present invention.
Sensor line 220 represents additional sensors that are not affixed to conduit 120 . Such additional sensors can be arbitrarily set at any point in the vineyard, either above or below vines or the ground. Additional sensors, such as soil nutrient and moisture sensors, may be needed in a different location than can be provided by the conduit.
Although a preferred embodiment of the invention uses a centralized control system, other embodiments can use distributed, or dedicated, processing at many points. For example, groups of emitters and sensors, or even each individual emitter and sensor, can have intelligent control. A microprocessor can use input from one or more sensors to control an emitter local to the sensor. This is useful where different parts of a vineyard need different degrees of irrigation. Some plants may be exposed to insects or disease and not others. With more finely-grained monitoring and control (achievable by either a centralized control system or distributed system) delivery of chemicals, water, and other materials can be made to only the exposed plants. Thus, a savings of chemicals is realized and plants that are not in need of treatment do not need to be risked by the application of unnecessary treatment.
Note that the preferred embodiment of the invention allows the conduit to be routed in existing trellis frameworks. Typically, no moving parts are used except for pumps in the flow control which are centrally located. In contrast to prior art methods, there is no tradeoff on water volume when spraying fungicides or insecticides as the amount of water to be used will be based on the best recommendation for coverage of the canopy for optimum pesticide performance. Once disease is detected, applications can be made immediately and as often as required.
Applications can be made to as many acres as the grower has pre-established for a given mix tank and pump set-up. Applications will require only minimal labor to pre-mix the pesticide and applicator exposure will be limited to only the mixing and loading operation. There will be no variability in the amount of pesticide applied as in the existing application methods which are based on speed of the tractor and pump pressure. Pre-calibration of the COD system will determine the timing needed to apply the desired amount of pesticide based on the pre-mix concentration and the total desired water volume. Pump pressure can be monitored, and if desired, flow control valves can be installed to further refine the actual volume applied. Pressure control valves installed throughout the piping framework will ensure equal application volume for the entire length of the trellis run, even at the furthest ends from the mix tank and pump. Using this system, an entire vineyard can be sprayed in less time that it takes to spray only a small block today with less risk and variability.
Thus, the invention creates value for growers by reducing their cost of applications and by reducing risks involved with making sure applications are made at the right time and in a timely manner. Additionally, growers can realize improvements in yield and quality of the high valued fruit. The invention provides more accurate timing of applications and better coverage of the vines, resulting in better disease management—one of the primary factors of quality and yield.
FIG. 2A illustrates a cut-away view of conduit 120 of FIG. 1 .
In FIG. 2A , conduit 270 houses four channels 272 , 274 , 276 and 278 . Emitter 280 is representative of emitters mounted onto conduit 270 at regularly-spaced intervals as described, above. Sensor and control cable 282 includes wires, fiber optic cables, etc. for communication with sensors, valves and other devices along conduit 270 . Cable 282 can be fixedly secured along conduit 270 , as desired.
Channels 272 , 274 , 276 and 278 can be used to dispense chemical solutions or other materials from the conduit. Additionally, the conduit has cavity 284 that can be used for dispensing water. In a preferred embodiment, each channel is a separate tube that is sealed from the other channels and from the cavity. Other embodiments can form channels as part of the conduit walls, integral with the conduit construction. Other designs are possible—for example, the cavity need not be used to dispense materials.
FIG. 2B shows a cutaway view of conduit 270 of FIG. 2A .
In FIG. 2B , capillary tubes are shown between each channel and emitter 280 . Emitter 280 includes a valve mechanism that can select materials in any of the channels. Additionally, inlet 290 allows emitter 280 to select materials (e.g., water) in cavity 284 . An emitter can use a computer-controlled valve-in-head system with multiple valves, as needed.
Each of the several, or many, emitters on the conduit is independently controllable by the control system of FIG. 1 . Thus, each channel, and the cavity, can be flooded with material to be dispensed and the dispensing can subsequently be controlled by the control system. Alternately, the emitters can be passive, for example, they can be simple through-holes sprinkler heads so that they are always “on” for all dispensing. In this latter case, the flow is controlled by flow control 202 of FIG. 1 , under the control of the control system. The flow control will then include a selective pump station for pumping materials into selected channels, or the conduit cavity, under the direction of control system 200 . Other variations are possible.
FIG. 2C shows a common-capillary arrangement where a single branching capillary is used for all of the channels and cavity. In this arrangement, the emitter has a single-valve control. Dispensing is accomplished by both flooding the appropriate channel and then controlling the valve to dispense the material. Simple one-way valves are shown as dark circles. These valves prevent mixing of materials among the channels.
Note that many types of conduit can be employed. The conduit need not be a completely enclosed “tube” as shown in FIGS. 2A-C . For example, the conduit can be comprised of bands or straps used at intervals to bundle together the tubes, or channels. In this case, emitters and sensors can be affixed to the bands or to one or more of the channel tubes. The conduit can be a flexible spiral of material within which the channel tubes are held. The conduit can be a tray, or trough, that is open at the top. Other variations are possible.
In a preferred embodiment, the conduit, channel, emitter and sensor assembly is flexible. This allows the conduit to be bent to follow paths among rows, as desired. Other embodiments can provide stiff piping with a means for joining additional pipe sections at different angles to achieve bends.
FIG. 3 shows details of the system of FIG. 1 .
In FIG. 3 , channel terminations 302 are connected to chemical tanks (and water) via manifold and pump 306 . The flow of each chemical is controlled by computer 304 in accordance with interface 310 . A preferred embodiment allows for many types of control configurations. A user can configure dispensing of each chemical at predetermined times and for specified amounts. Another option is for sensor data to automatically trigger dispensation. For example, an optical sensor can help determine the size of vine leaf area (or other crops) based on the amount of light that is blocked so that the amount of chemicals dispensed at different points in time can be increased as the vine leaf area increases. Other sensors can report on the amount of rain, temperature and humidity, soil moisture conditions, etc., so that delivery of nutrients and water can be adjusted accordingly.
A software program that is automating the system by receiving and responding to the various sensor and control inputs can be resident locally to computer 304 . This software can be configured and updated from a manufacturer or supplier. Alternatively, computer 304 can be controlled via the Internet, or other network or communication link, by a remote source, such as a service supplier. The system can be completely monitored by the service supplier. Monitoring of the entire system allows a service supplier to provide additional benefits to the grower such as automatically ordering chemical supplies, using advanced data and statistics such as satellite imagery, ground and satellite weather data, and environmental reports, ensuring that the system is functioning properly, etc.
In FIG. 3 , conduit 300 includes emitter sensors on both the top and bottom of the conduit. Each emitter need not be connected to all of the channels. In a preferred embodiment, fungicides, insecticides and growth regulators are dispensed through emitters on the top of the conduit while fertilizer and water are dispensed from the bottom emitters. Naturally, other arrangements are possible. Sensors are positioned along the top of the conduit but can also be positioned anywhere on the conduit, or on additional sensor lines that are not part of the conduit.
FIGS. 4A and B illustrate some of the different types of sensors that are appropriate for use with the present invention.
In FIG. 4A light, temperature, relative humidity, insect, and leaf moisture detecting sensors are present. Light sensors allow the canopy size or leaf area to be determined by detecting the amount of shade generated under the plant's growing leaves. Light sensors can also be used to determine how much sunlight the plants are obtaining (assuming the sensors are moved away from the plant shade). Insect detectors include sticky traps, pheromone detectors and DNA sensitive analysis tools. Leaf wetness detectors simulate the absorbency of leafs so that moisture on the surface of the detector approximates plant leaf wetness.
FIG. 4B shows additional sensors as an infrared light transmitter and detector for sensing plant nutrition and health deficiencies depending on the amount of transmitted or absorbed infrared light. Sugar accumulation in grape bunches can be determined by connecting selected bunches of grapes to pH probes or other instruments capable of measuring soluble solids (Brix) in grape berries.
By using the system of the present invention, efficiencies not possible in the prior art can be realized. The control system can accurately measure the pressure and volume of delivery of water and chemicals. The delivery of materials can be more precisely directed to where it is needed. The delivery is also performed as needed so care of the crops is more accurate and effective and there is less waste. No human intervention is necessary. Heavy mechanical devices are eliminated at a concomitant savings in fuel and maintenance costs.
Insecticides can be applied based on measurements of remote sensor data, from regional or national agencies, from local sensors, etc. This allows newly found research data on bug lifecycles and behavior to be used in growing practice almost immediately. Wind and weather sensors can be used to prevent dispensing of harmful chemicals when a chance of unwanted high dispersion is likely. Should a high wind come up during application of chemicals, the application can be immediately stopped and the dosage continued at a later time. Preventative chemicals can be applied to the crops when the “disease pressure” is high.
Crop growth rate can be accurately measured and used in application of all types of materials. Accurate projections and forecasting can be made from the detailed sensing of all aspects of crop growth and maintenance. Alarms can be triggered when urgent conditions are detected, such as insect infestations or disease. Risk evaluations can be computed based on sensor detections. Such projections and evaluations are useful for growers to profitably manage their operations.
Although the invention has been discussed with respect to specific embodiments thereof, these embodiments are merely illustrative, and not restrictive, of the invention.
For example, although the invention has been discussed primarily with respect to grapevine growing, it should be apparent that aspects of the invention can be used to advantage with any type of crop, flower, tree, fungus, or other type of plant. In general, the present invention can be used to advantage to monitor, manage and maintain a system of any type of developing entities that can benefit from controlled dispensing of materials. For example, features of the present invention may be applied to feeding and disinfecting livestock. Other applications will be apparent.
Although the materials dispensed by the present invention have been presented as primarily liquids, it should be apparent that both solid and gas material dispensing can benefit from aspects of the present invention.
Thus, the scope of the invention is to be determined solely by the appended claims. | A system for automating the growing of crops, such as grapevines. Combinations of data from sensors local to a vineyard, and from optional remote stations and sensors, is combined with a control system to accurately control the dispensing of water and chemicals such as insecticides, disease prevention fungicides and fertilizers. The materials are dispensed through a multiple channel conduit which allows conflicting, or incompatible, types of materials to be transported through a common assembly. Sensors are attached to the conduit so that the placement of sensors can occur simultaneously with the laying of the conduit. This approach also ensures correct placement and spacing of the sensors with respect to each plant, or plant area, to be monitored and treated. | 0 |
TECHNICAL FIELD
The present invention relates, in general, to a testing device for a fuel or gas cap and, more particularly, to a testing device which accurately and rapidly measures the rate of leakage of air and/or fuel vapors through a fuel or gas cap and compares same against a leakage rate standard for same so that those caps with leakage rates that exceed the standard can be readily identified.
BACKGROUND ART
The testing of the functional systems of vehicles has become quite sophisticated and requires extensive test procedures to ensure that the vehicle components are operating properly and that the overall system performance is in accordance with specific guidelines. The Federal Environmental Protection Administration (EPA) has established extensive regulations limiting emissions from motor vehicles. One area of particular interest is the vehicle fuel system. The loss of fuel through evaporation to the atmosphere is wasteful and environmentally harmful since fuel vapors contribute to unwanted hydrocarbon pollution. In an effort to limit such pollution, the EPA has proposed that fuel or gas caps be pressure tested. Testing apparatus and procedures have been developed to determine the integrity of fuel caps, however, such apparatus typically involve expensive flow rate measurement devices or utilize relatively low cost measurement devices that do not yield consistent results.
In view of the foregoing, it has become desirable to develop a more cost effective and efficient apparatus and method for testing the integrity of fuel or gas caps with respect to possible leakage of air and/or fuel vapors through same.
SUMMARY OF THE INVENTION
The present invention provides an apparatus and method for testing the integrity of fuel or gas caps for leaks. As such, the present invention includes a microprocessor which allows an air pressure source to pressurize an air reservoir to a predetermined first pressure. The microprocessor then permits air within the air reservoir to pass to the fuel or gas cap under test and also through a reference orifice until a predetermined second pressure has been reached at which time an internal timer within the microprocessor is actuated. The air continues to pass to the fuel or gas cap and through the reference orifice until a predetermined third pressure has been reached at which time the elapsed time on the internal timer is stored and a solenoid valve is deactuated stopping air flow to the fuel or gas cap under test. The air from the air reservoir is then allowed to continue to pass only through the reference orifice until a predetermined fourth pressure has been reached at which time the internal timer within the microprocessor is again actuated. Air continues to flow through the reference orifice until a predetermined fifth pressure has been reached at which time the elapsed time on the internal timer is stored. By comparing the ratio of the first elapsed time (air flow to the fuel or gas cap and through the reference orifice) with the second elapsed time (air flow through the reference orifice only) against a predetermined standard ratio, a determination can be made whether air and/or vapor leakage through the fuel or gas cap exceeds an acceptable limit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating the pneumatic circuit of the fuel cap tester of the present invention.
FIG. 2 is a schematic diagram of the electrical circuit utilized by the fuel cap tester of the present invention.
FIG. 3 is graph of pressure versus time illustrating the pressure drops which occur within the system of the present invention during a typical test of a fuel or gas cap.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings where the illustrations are for the purpose of describing the preferred embodiment of the present invention and not intended to limit the invention described herein, FIG. 1 is a schematic drawing illustrating the pneumatic circuit for the fuel cap tester 10 of the present invention. As such, the pneumatic circuit includes an air pump 12 , a 2-way air inlet solenoid valve 14 , an air reservoir 16 , a pressure transducer 18 , a filter 20 , a reference orifice 22 , a 2-way air output solenoid valve 24 and a fuel cap adapter 26 . The air pump 12 is powered by a 12 volts D.C. source (not shown) and its output is connected, via tubing 30 , to the input to air inlet solenoid valve 14 , which is also powered by the 12 volts D.C. source. The output of solenoid valve 14 is connected, via tubing 32 , to an input to air reservoir 16 . Pressure transducer 18 is also connected, via tubing 34 , to another input to air reservoir 16 to monitor the air pressure therein. The output of air reservoir 16 is connected to a T-fitting 36 having one of its outputs connected to the input to filter 20 and the other of its outputs connected to the input to air output solenoid valve 24 which is also powered by the 12 volts D.C. source. The output of filter 20 is connected to the input to reference orifice 22 by tubing 38 . The output of reference orifice 22 is allowed to vent to the atmosphere. The output of solenoid valve 24 is connected to the input to fuel cap adapter 26 by tubing 40 . The fuel or gas cap to be tested (not shown) is attached to fuel cap adapter 26 for testing purposes.
The pneumatic circuit for the fuel cap tester 10 illustrated schematically in FIG. 1 is controlled by the electrical circuit shown schematically in FIG. 2 . In this latter Figure, those components which been already described with respect to FIG. 1 carry like reference numerals. The circuit illustrated in FIG. 2 is controlled by a microprocessor 50 having a plurality of input circuits and output circuits associated therewith. With respect to the input circuits, one input circuit (shown schematically) includes pressure transducer 18 , a filter/amplifier 52 , a voltage comparator 54 and a digital to analog converter 56 . In this instance, the output of pressure transducer 18 is connected to the input to filter/amplifier 52 whose output is connected to the non-inverting input of voltage comparator 54 . The analog output of digital to analog converter 56 is connected to the inverting input of voltage comparator 54 . The output of voltage comparator 54 is connected to an input to microprocessor 50 . An output from microprocessor 50 is connected to the digital input of analog to digital converter 56 . Another input to microprocessor 50 is a push button 58 which is utilized to actuate the entire testing system. In addition, a RS232 receiver buffer 60 is connected to another input to microprocessor 50 . With respect to the output circuits associated with microprocessor 50 , separate outputs from microprocessor 50 are connected to a plurality of light emitting diodes 62 and to the separate inputs to solenoid valve 14 , solenoid valve 24 , air pump 12 , and to an RS232 transmitter buffer 62 . A power supply 64 is provided for the electrical requirements of this system and includes reverse voltage protection, voltage regulation and overcurrent protection.
During system assembly, some calibration values are permanently stored in a serial EEPROM associated with the microprocessor 50 and used during the fuel or gas cap testing procedure. Such values include air pump frequency, full scale calibration, zero value calibration and test ratio. With respect to air pump frequency, because of mechanical tolerances within the air pump 12 , it is necessary to determine the most efficient driving frequency for the system and to store this value in the serial EEPROM for use during the fuel or gas cap testing process. As for full scale calibration, because of the electrical variation between pressure transducers 18 , a source of 36 inches of water pressure is applied to pressure transducer 18 while the combination of the digital to analog converter 56 , voltage comparator 54 and microprocessor 50 executes a successive approximation algorithm to digitize this pressure value for storage in the serial EEPROM. From this value, the digital value for one inch of water pressure is calculated by dividing the stored full scale value for same by 36 . Regarding the zero value calibration, since the pressure transducer 18 is not zero compensated over a range of temperatures, a known zero water pressure value must be established before the testing system is operated and this zero pressure value must be added to the full scale pressure value to compensate for temperature. Because the air reservoir 16 might not be fully discharged between consecutive fuel or gas cap tests, a capacitor (not shown) having a 2.5 minute discharge period is charged by the microprocessor 50 through a blocking diode (not shown) each time the air reservoir 16 is pressurized. When the fuel or gas cap testing procedure is started, the charge on the capacitor is checked. If the capacitor is fully discharged, the digital to analog converter 56 , voltage comparator 54 and microprocessor 50 combination, through the utilization of a successive approximation algorithm, digitizes the value of the output of the filter/amplifier 52 and stores this value in the serial EEPROM. If the capacitor is not fully discharged, the previously stored zero pressure value in the serial EEPROM is used. Lastly, with respect to the test ratio, during system calibration, an external 60 cc orifice is connected to the fuel cap adapter 26 . and the same algorithm that is used in fuel or gas cap testing is executed. The test result (test ratio) is stored in the serial EEPROM and is used for comparison purposes during the actual fuel or gas cap testing procedure.
Upon application of power to the system, the microprocessor 50 initializes all of its variables and its input/output ports. The microprocessor 50 also polls the port associated with the start push button 58 . When the push button 58 is actuated, the microprocessor 50 actuates solenoid valve 24 causing it to open. The microprocessor 50 then “reads” the output of voltage comparator 54 and if the output is low indicating that the aforementioned capacitor is discharged, the microprocessor 50 performs an analog to digital conversion with respect to the pressure transducer 18 to obtain the zero pressure voltage and stores this value in the serial EEPROM. If the output of voltage comparator 54 is not low indicating that the aforementioned capacitor has not fully discharged, the microprocessor 50 utilizes the previously stored zero pressure voltage in the serial EEPROM. After the foregoing has occurred, the microprocessor 50 sets the output of the digital to analog converter 56 to the voltage corresponding to 36 inches of water pressure previously stored in the serial EEPROM. The microprocessor 50 then actuates the air pump 12 and solenoid valve 14 causing valve 14 to open allowing air reservoir 16 to be pressurized. When the output of the voltage comparator 54 goes high indicating that the air reservoir 16 has been pressurized to a pressure of 36 inches of water, solenoid valve 14 is then deactuated causing valve 14 to close preventing further pressurization of air reservoir 16 . This is shown graphically in FIG. 3 which is a graph of pressure within the air reservoir versus time. The microprocessor 50 then sets the output of the digital to analog converter 56 to a voltage corresponding to 31 inches of water pressure and allows air to pass from the air reservoir 16 and leak through the fuel or gas cap under test and the reference orifice 22 causing the pressure within the air reservoir 16 to drop. The pressure drop or decay rate, referred to hereinafter as the first pressure decay rate, is allowed to stabilize. The microprocessor 50 then polls the output of the voltage comparator 54 until it goes low indicating that the pressure within the air reservoir 16 has dropped to 31 inches of water due to leakage through the fuel or gas cap under test and the reference orifice 22 . When this latter pressure has been reached, the microprocessor 50 starts its internal timer and sets the output of the digital to analog converter 56 to a voltage corresponding to 29 inches of water pressure. The microprocessor 50 then polls the output of the voltage comparator 54 until it goes low indicating that the pressure within the air reservoir 16 has dropped to 29 inches of water. When this latter pressure has been reached, the microprocessor 50 stops its internal timer, stores the elapsed time in a random access memory, and deactuates solenoid valve 24 causing it to close. This elapsed time value is actually the time required for the leak through the reference orifice 22 and through the fuel or gas cap under test to cause the pressure within the air reservoir 16 to drop from 31 to 29 inches of water pressure. This time interval, which represents the first pressure decay rate, is subsequently referred to herein as T 1 .
Since microprocessor 50 has deactuated solenoid valve 24 causing it to close, the reference orifice 22 is the only leak within the system. The microprocessor 50 then sets the output of the digital to analog converter 56 to a voltage corresponding to 28 inches of water pressure and allows air to pass from the air reservoir 16 and leak through the reference orifice 22 causing the pressure within the air reservoir to drop. The pressure drop or decay rate, referred to hereinafter as the second decay rate, is allowed to stabilize. The microprocessor 50 then polls the output of the voltage comparator 54 until it goes low indicating that the pressure within air reservoir 16 has dropped to 28 inches of water. When this latter pressure has been reached, the microprocessor 50 starts its internal timer and sets the output of the digital to analog converter 56 to a voltage corresponding to 26 inches of water pressure. The microprocessor 50 then polls the output of the voltage comparator 54 until it goes low, thus indicating the pressure within air reservoir 16 has dropped to 26 inches of water. When this latter pressure has been reached, the microprocessor 50 stops its internal timer and stores the elapsed time in the random access memory. This elapsed time value is actually the time required for a leak through the reference orifice 22 to cause the pressure within air reservoir 16 to drop from 28 inches to 26 inches of water. This time interval, which represents the second pressure decay rate, is subsequently referred to herein as T 2 .
Utilizing the aforementioned time intervals or pressure decay rates of T 2 and T 1 , the system divides T 2 by T 1 and the resulting ratio is compared to the test ratio that was previously stored in the serial EEPROM during the 60 cc calibration test. If the resulting ratio of T 2 /T 1 is less than the test ratio, the microprocessor 50 actuates the green light emitting diode indicating that the fuel or gas cap passed the test satisfactorily. If, the ratio T 2 /T 1 is greater than the test ratio, the microprocessor 50 actuates the red light emitting diode indicating that the fuel or gas cap failed the test.
Certain improvements and modifications will occur to those skilled in the art upon reading the foregoing. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability, but are properly within the scope of the following claims. | An apparatus and a method for testing the integrity of fuel or gas caps for leaks is disclosed. A microprocessor controls the pressurization of an air reservoir which selectively allows air to pass to either the combination of the fuel cap under test and a reference orifice or to only the reference orifice and computes the ratio of the time required for the pressure within the air reservoir to drop between predetermined pressure levels for the combination of the fuel cap under test and the reference orifice versus only the reference orifice and compares same against a standard ratio to determine whether the leakage rate through the fuel cap meets an acceptable limit. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to medical equipment. More specifically, the invention relates to an endotracheal tube holder which is specially adapted for use in neo-natal care.
[0003] 2. Description of Related Art
[0004] An endotracheal tube holder is used during various medical procedures. An endotracheal tube is inserted through a patient's mouth, and into the trachea. The purpose of such intubations may be to ensure proper ventilation, or for other reasons. Other tubes may also be inserted, such as a feeding tube. When these tubes are to remain in the patient for a period of time, it is common to anchor the tubes to the patient in some manner. For example, medical tape can be applied directly to the patient's face. There also appear to be an assortment of head and neck braces which hold a mouthpiece against the patient's mouth, as will now be discussed.
[0005] The state of the art in endotracheal tube holders is replete with different designs intended to address different issues. For example, some of the designs are intended, at least partially, to address the issue of attachment to a patient. Others are designed for more securely holding the endotracheal tube so that it does not slip out of the trachea. Others are intended to reduce the damage caused to patients by extended attachment of tubes via medical tape on the patient's face. It is useful to examine what some of these prior references teach in order to illustrate their shortcomings.
[0006] There are at least several endotracheal tube holders that are relevant to this disclosure. For example, U.S. Pat. No. 5,551,421 issued to Noureldin et al. teaches an endotracheal tube holder with a ratcheting device for positioning the tube away from the center of the patient's mouth to prevent obstruction in the flow of regurgitated food or fluid. The tube holder includes straps for securing it to the patient's neck.
[0007] U.S. Pat. No. 5,555,881 issued to Rogers et al. describes an Endotracheal tube holder that has a collar member for securely holding the tube, and a brace coupled to the collar member that holds the tube in front of the patient's mouth. The brace is disposed between the patient's upper lip and nose, and the collar member extends downwards therefrom. Alternative embodiments address others means for holding the tube. Teeth within the collar member can grip and hold a tube inserted therethrough.
[0008] U.S. Pat. No. 5,490,504 issued to Vrona et al. teaches an endotracheal tube holder and a holding device for securing the holder to the patient with a neck brace. The lateral position of the endotracheal tube is modifiable so that it can be moved to one side for access.
[0009] U.S. Pat. No. 5,419,319 issued to Werner teaches an endotracheal tube holder comprising a rigid face plate which conforms to the patient's mouth. The tube holder hangs from the face plate and in front of the patient's mouth. The position of the tube holder is adjustable in front of the patient's mouth, and holes for straps are provided in the mouthpiece to attach it to the patient's head.
[0010] U.S. Pat. No. 5,368,024 issued to Jones teaches a system for holding an endotracheal tube in front of a patient's mouth. The system comprises disks which are stuck to the patient's cheeks on either side of the mouth, and straps are provided for providing pull and counter-pull on the disks to hold them in place. The tube holder comprises an open ring that can be pulled apart to insert the tube, and which will pinch the tube when released.
[0011] U.S. Pat. No. 5,345,931 issued to Battaglia, Jr. teaches an endotracheal tube holder with provides a rigid and conforming face piece which has a tube holder that can be adapted to different sizes of tubes. Straps are secured to the rigid face plate to hold it in place to the patient's neck. The tube holder fits in a track of the rigid face plate, and can slide within the track to hold the tube in any position horizontally in front of the patient's mouth.
[0012] U.S. Pat. No. 5,402,776 issued to Islava teaches an endotracheal tube holder which provides a means for securing the tube in front of the patient's mouth by a clamp coupled to a rigid face plate. The face plate is secured by a strap around the patient's head.
[0013] There are several important disadvantages to the endotracheal tube holders described in the patents above. First, all of these endotracheal tube holders are dangerous for neo-natal use. There are special considerations when using an endotracheal tube holder for small infants. For example, their skin is very sensitive. Medical tape can cause a rash, or even a more severe allergic reaction. The skin can even be damaged directly when the medical tape is removed. It is noted that the Jones patent is the only one which shows an endotracheal tube holder attached to a young person. The remaining endotracheal tube holders either show the device coupled to an adult, or do not show the device attached to a person. Furthermore, the Jones patent teaches an adhesive disk that is secured to the patient's cheek.
[0014] Another reason that the prior art patents are dangerous for neo-natal use is that the neck and head braces would probably do damage to the neck and/or head of a neo-natal infant. This is because of the extremely delicate nature of a neo-natal patient's neck and head structure. Any type of applied pressure is undesirable because it can interfere with the normal expansion and reshaping of cranial bones after birth. The prior art references fail to teach the need or the ability to provide an attachment system which can provide secure attachment of an endotracheal tube holder to a neo-natal patient without risking damage to the patient. Furthermore, the references also fail to teach an attachment system which can be quickly and easily adjusted for size and fit, and even replaced.
[0015] Another danger that is not addressed by the prior art references is the need for eye protection. Neo-natal patients in particular are very susceptible to retinal damage because of the harsh visible or ultraviolet lighting conditions that are often necessary for warmth, visual monitoring, or medical treatment. The prior art references fail to demonstrate the need or ability to provide eye protection.
[0016] The prior art references fail to teach the need for or the ability to provide an endotracheal tube holder which can also accommodate another tube. For example, feeding tubes are sometimes used at the same time as an endotracheal tube. The feeding tube is also put into the patient's mouth.
[0017] Another danger that is not addressed by the prior art references is the importance of providing some means for preventing damage a patient's mouth. The gums and teeth of a neo-natal patient are particularly susceptible to damage from constant contact with an object that is forcing it to conform to the shape of some other object. In particular, the endotracheal tube or the endotracheal tube holder can cause damage. The prior art references fail to demonstrate the need for or the ability to provide some protection for the gums and teeth.
[0018] The prior art references fail to demonstrate the need for or the ability to provide some protection for the patient's cheeks. The references typically show a face plate assembly that rests directly on the patients cheeks, or even worse, is attached to the cheeks by adhesive.
[0019] Therefore, it would be an advantage over the prior art to provide an endotracheal tube holder which could be secured to the neo-natal patient without having to use a brace that would apply pressure to the infant's head and/or neck. Essentially, the attachment system does not use any elastic compression to secure the endotracheal tube holder to the patient. It would be a further advantage to provide an endotracheal tube holder that can be quickly and easily adjusted in size, replaced, provide adjustable eye protection, enable simultaneous placement of more than one tube into the patient's mouth, and provide protection to the patient's gum, teeth, cheeks, and mouth.
BRIEF SUMMARY OF THE INVENTION
[0020] It is an object of the present invention to provide a method and apparatus for holding an endotracheal tube stationary relative to a mouth of a neo-natal patient.
[0021] It is another object to provide an endotracheal tube holder which can be held stationary relative to the mouth without having to use an elastic attachment mechanism.
[0022] It is another object to provide an endotracheal tube holder which can be held stationary relative to the mouth without having to use an adhesive attachment mechanism.
[0023] It is another object to provide an attachment mechanism for the endotracheal tube holder to which adjustable eye protection can be attached.
[0024] It is another object to provide an endotracheal tube holder which enables simultaneous anchoring of a second tube relative to the patient's mouth.
[0025] It is another object to provide an endotracheal tube holder which also provides protection to a neo-natal patient's gums and teeth.
[0026] It is another object to provide an endotracheal tube holder which provides protection to a neo-natal patient's mouth structure.
[0027] It is another object to provide an endotracheal tube holder and attachment mechanism that will not interfere with normal expansion and reshaping of cranial bones after birth.
[0028] It is another object to provide an endotracheal tube holder with an attachment mechanism that is quickly and easily adjustable or removable.
[0029] The presently preferred embodiment of the present invention is an endotracheal tube holder comprising a flexible arcuate face plate, a tube holding member disposed in the face plate in front of the patient's mouth, and a means for attachment which does not cause elastic compression on the neo-natal patient. A bite block is provided for preventing damage caused by the neo-natal patient biting on the endotracheal tube, the tube holding member is able to adjust to different sizes of endotracheal tubes to thereby hold them firm, an additional tube can be added for simultaneous access to the patient's mouth, cheek pads prevent injury to the patient's cheeks, and integral eye protection is provided on the means for attachment.
[0030] The face plate curves around the patient's face in front of the mouth. On the ends of the face plate are a plurality of attachment slots in the two ends of the arcuate face plate to which attachment straps are coupled and extend around the patient's head to thereby secure the arcuate face plate to the patient, and a ratcheting endotracheal tube holder which is disposed within a U-shaped receptacle at a midpoint of the arcuate face plate.
[0031] In a first aspect of the invention, the ratcheting endotracheal tube holder which clamps around the endotracheal tube is comprised of a cylindrical length of rigid material. The cylindrical material is then caused to pivot open. The endotracheal tube is disposed within a depression within the cylindrical material, and the cylindrical material is then caused to pivot shut around the endotracheal tube.
[0032] In a second aspect of the invention, a ratcheting mechanism causes the cylindrical material to close around the endotracheal tube at varying degrees of tightness. The cylinder is then disposed within the U-shaped receptacle at the midpoint of the face plate.
[0033] In a third aspect of the invention, a second hole is provided in the endotracheal tube holder through which another tube can be disposed.
[0034] In a fourth aspect of the invention, a non-elastic headband is provided with a hook and loop fastening system such as straps having VELCRO(™) to give it sufficient structure such that the face plate can be held in place in front of the patient's mouth. The hook and loop fastening system of VELCRO(™) enables the head band to be quickly and easily adjusted for proper fit, or removal from the face plate.
[0035] In a fifth aspect of the invention, a tubular member extends from the U-shaped receptacle and into the patient's mouth as a bite block to prevent damage to the patient's teeth and gums as they bite on the endotracheal tube holder.
[0036] In a sixth aspect of the invention, cheek pads are disposed under the attachment ends of the face plate to prevent them from injuring the patient's cheek and cheek bones.
[0037] In a seventh aspect of the invention, an adjustable eye covering is coupled to the attachment straps to thereby protect the patient's eyes from surrounding light sources.
[0038] These and other objects, features, advantages and alternative aspects of the present invention will become apparent to those skilled in the art from a consideration of the following detailed description taken in combination with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0039] FIG. 1 is a perspective elevational view of the components of the presently preferred embodiment which is constructed in accordance with the principles of the present invention.
[0040] FIG. 2A is a front elevational view of the face plate of the presently preferred embodiment, which illustrates the U-shaped receptacle and the attaching arms.
[0041] FIG. 2B is a top elevational view of the face plate shown in FIG. 2A .
[0042] FIG. 2C is a side elevational profile view of the face plate shown in FIG. 2A .
[0043] FIG. 3 is a side elevational and cut-away profile view of the presently preferred embodiment of the tube holding member by which the endotracheal tube is held.
[0044] FIG. 4A is an elevational profile view of the tube holding member of FIG. 3 taken along the perspective of A-A.
[0045] FIG. 4B is an elevational profile view of the tube holding member of FIG. 4A with the top member pivoted away from the bottom member.
[0046] FIG. 5 is an elevational top view of an alternative embodiment of the tube holding member with a bite block extending inward towards the patient's mouth.
[0047] FIG. 6 is an elevational profile view of a patient with the endotracheal tube holding system attached to the patient using a preferred arrangement of attaching straps.
[0048] FIG. 7 is an elevational profile view of a patient with the endotracheal tube holding system attached to the patient in an alternative arrangement of attaching straps, and with an optional eye protection system for shielding the eyes of neo-natal patients.
[0049] FIG. 8A is a top elevational view of a cheek pad that surrounds the attaching arm of the face plate to protect the patient's cheeks.
[0050] FIG. 8B shows the cheek pad of FIG. 8A and its relative position with respect to the attaching arm before the hook and loop fastening system of VELCRO(™) straps are folded over
DETAILED DESCRIPTION OF THE INVENTION
[0051] Reference will now be made to the drawings in which the various elements of the present invention will be given numerical designations and in which the invention will be discussed so as to enable one skilled in the art to make and use the invention. It is to be understood that the following description is only exemplary of the principles of the present invention, and should not be viewed as narrowing the claims which follow.
[0052] It is useful to have an overview of the present invention before delving into the detailed description of the preferred embodiment. Accordingly, it is observed that the present invention advantageously provides features of an endotracheal tube holder which are uniquely adapted to the special needs of a neo-natal patient. However, these special adaptations are also applicable to young children or adult patients. Therefore, the principles described hereinafter find application to patients of any age group. Nevertheless, the advantages of the present invention will be described from the perspective of the special needs of the neo-natal patient.
[0053] The advantageous features to be described are designed with the purpose of safeguarding very sensitive bone and tissue of a neo-natal patient. However, even though neo-natal patients are particularly vulnerable, everyone undergoing medical care appreciates careful handling. It is unfortunate that patients sometimes suffer injuries as a result of the care they are receiving. The injuries are typically considered to be unavoidable.
[0054] The presently preferred embodiment of the present invention is designed to accomplish the same purposes as the medical equipment it is designed to replace, while at the same time, and provide a new level of comfort and protection against the injuries that the medical equipment can cause.
[0055] FIG. 1 is provided as an overview of the general operation of the presently preferred embodiment of the present invention. This figure shows that the invention is comprised of three separate components which are combined to create an attachable endotracheal tube holding system. In this view, the components are shown in perspective to better illustrate the relationships between them.
[0056] The first component is the arcuate face plate 12 of the endotracheal tube holder 10 which forms the framework of the endotracheal tube holding system. The face plate 12 is comprised of a semi-flexible arcuate material which conforms to the curvature of a patient's face at the mouth, and extends backwards along the patient's cheeks. The face plate 12 has a U-shaped receptacle 14 centered in a midpoint of the face plate 12 . The open end of the U-shaped receptacle 14 is open upwards relative to the face plate 12 .
[0057] The face plate 12 also has two attaching ends 16 . The attaching ends 16 are each designed to receive attachment straps 18 , the ends of which are partially shown in FIG. 1 . In this presently preferred embodiment, the attachment straps 18 are coupled to slots 20 in the attaching ends 16 by The hook and loop fastening system of VELCRO(™). The U-shaped receptacle 14 is made of a generally rigid material, but is sufficiently flexible so as to allow a tube holding member 22 to slide therein and snap securely into place.
[0058] The tube holding member 22 is designed to open along its length, allowing an endotracheal tube 24 to be disposed therein, and to then be closed tightly around the endotracheal tube 24 , leaving sufficient space for air or other fluids to pass therethrough. The tube holding member 22 is then disposed within the U-shaped receptacle 14 and held securely.
[0059] The endotracheal tube 24 is inserted into the patient's trachea, and the endotracheal tube holder 10 is positioned on the patient's face in front of the mouth. The attachment straps 18 are then coupled to the face plate 12 and adjusted so as to pull the face plate 12 gently but firmly against the patient's mouth so that the endotracheal tube 24 cannot be dislodged from the patient's trachea.
[0060] More detailed figures of the components described generally in FIG. 1 will enable the user to better understand the specific benefits of the endotracheal tube holder 10 described above.
[0061] FIG. 2A is a front profile elevational view of the face plate 12 . It is apparent that the U-shaped receptacle 14 has two upper lips 26 which help to retain the tube holding member 22 ( FIG. 1 ) after it is inserted.
[0062] FIG. 2B is a top profile bird's eye view of the face plate 12 looking down from above. The flexible arms 28 are able to bend and conform to the patient's cheeks.
[0063] FIG. 2C is a side profile elevational view of face plate 12 . The slots 20 are clearly visible. It should be remembered that the slanting of the slots is provided to assist in attaching the attachment straps 18 to the face plate 12 . However, these slots 18 can be slanted in any preferable direction, in accordance with the requirements of the particular attachment straps 18 being used.
[0064] FIG. 3 is a cut-away elevational profile view of the tube holding member 22 which holds the endotracheal tube 24 ( FIG. 1 ). In the presently preferred embodiment, the tube holding member 22 is shown as only wrapping around the endotracheal tube along a portion 30 of its length. Specifically, the portion 30 which wraps around the endotracheal tube 24 is disposed within the U-shaped receptacle 14 of the face plate 12 .
[0065] FIG. 4A is an end elevational profile view of the tube holding member 22 as seen from the perspective A-A shown in FIG. 3 . The tube holding member 22 has a top half 32 , a bottom half 34 , a hinge 36 , and the hole 38 for the endotracheal tube 24 . In an alternative embodiment, a second hole 40 is shown as a bore through the tube holding member 22 . The hole 40 is large enough to fit a second tube for passing fluids, such as through a feeding tube. It is observed that inserting a feeding tube through the hole 40 and into the patient's mouth had advantages over a tube inserted through the nasal passages. For example, nasal passage damage is avoided, and the patient is able to breathe without an obstruction in the nasal passage.
[0066] The hole 40 can also be used to insert a cleaning tube. A cleaning tube is inserted to remove secretions from the patient's throat.
[0067] The tabs 46 are provided for releasing the ratchet hook 42 ( FIG. 4B ). Gently pressing on the tabs 46 causes the ratchet hook 42 to be released from the complementary receiving indentations 46 ( FIG. 4B ).
[0068] FIG. 4B is an illustration of the tube holding member 22 shown in FIG. 4A , but in an open position. What is important to recognize in this illustration is the locking mechanism. It is advantageous to provide a locking mechanism which is adjustable to the particular diameter of the endotracheal tube that is being held. Accordingly, it is preferable to utilize some type of ratchet mechanism as shown. The top half 32 has a ratcheting hook 42 which can be pressed into various and deeper complementary receiving indentations 46 in the bottom half 34 . In this way, the endotracheal tube is always held tightly, regardless of its diameter.
[0069] It should be recognized that the ratcheting hook and receiving indentations are only an example of how the tube holding members 22 is able to grasp the endotracheal tube. This particular method has the advantage of being easily adjustable, but there are other methods which can also be used.
[0070] Holding the endotracheal tube is an important feature. If the endotracheal tube is free to move within the patient's mouth, the endotracheal tube can rub against the palate causing serious injury. Likewise, it is important that the face plate be held securely. Otherwise, the movement of the endotracheal tube holder can cause damage to the teeth and gums.
[0071] An alternative embodiment of the tube holding member 22 is shown in FIG. 5 . FIG. 5 is a top elevational view which shows that an end of the tube holding member now extends into the mouth of the patient. This extension or bite block 44 is then covered by a sleeve of soft rubber. The bite block functions as a pacifier for the neo-natal infant. It also protects the gums from the harder material of the endotracheal tube that is inserted through the tube holding member 22 . It is noted that prolonged pressure on the palate of the upper mouth can cause cleft palate. The soft rubber sleeve spreads out the area of contact between the teeth, gums and the endotracheal tube. This important because infants will use the endotracheal tube as a pacifier, causing a condition known as palatal groove which can extend to the alveolar ridge. This can affect the development of the lateral incisors, causing the condition Hypoplasia.
[0072] Another advantage of the present invention is that is addresses the need for visual monitoring of sores that can develop on the lips and the corners of the mouth. The face plate is a clear polycarbonate material, enabling health care workers to easily inspect the patient, and treat the conditions as soon as they are recognizable.
[0073] Finally, the details of the attachment straps 18 illustrated in FIGS. 6 and 7 should only be considered to be some examples of the possible configurations that they can form. In this preferred embodiment, however, they provide a distinct advantage over the prior art. Specifically, the attachment straps 18 are constructed of a soft and non-elastic material. The material is formed from strips so that the material is padded inside for added comfort as the patient lays on them. Preferably, the strips are sewn together at stress joints, thus only requiring The hook and loop fastening system of VELCRO(™) in order to tighten the whole attachment structure. Constructing the strips from a non-elastic material is important for reducing unwanted stresses on the cranial bones of the neo-natal patient.
[0074] FIG. 6 illustrates the presently preferred embodiment of the attachment straps 18 . This configuration shows that a first attachment strap 50 extends around the base of the neck. A pair of straps 52 (only one shown) then form a V by traveling up from the base of the neck and over the top of the head until they meet at a strap 54 that extends upwards from the face plate 12 . A stabilizing strap 56 extends across the forehead and is coupled at both ends to strap 54 .
[0075] FIG. 7 is provided to show an alternative embodiment. An important new element is the eye protection 60 that is disposed on the eyes. This eye protection 60 also serves the function of stabilizing the straps on the head. The change that is also shown in the straps 62 that extend from the base of the neck to the forehead, and across the back of the head with strap 64 are only illustrative of the numerous modifications in shape of the straps that are within the scope of this invention. It is critical that the straps be non-elastic, and yet padded for comfort. The hook and loop fastening system of VELCRO(™) on the ends of the straps where they are coupled to the face plate enables the straps to be adjusted according to the dimensions of the head around which they are placed.
[0076] Another alternative embodiment of the present invention is a modification to the face plate 12 . No matter how flexible or rigid the face plate 12 is constructed, a neo-natal patient will probably be laying at least partially on the attaching ends. The attaching ends are necessarily constructed of a durable plastic material. Accordingly, the attaching ends are likely to “dig into” the patient's cheeks and cheek bones. This is not only painful, but it can deform the cranial bones. In the alternative embodiment, the attaching ends are padded. This padding can be added in many ways.
[0077] FIG. 8 is provided as an illustration of a cheek pad 70 . A cheek pad 70 that is constructed using The hook and loop fastening system of VELCRO(™) can be used to wrap around the ends of the flexible arms 28 . A simple embodiment of the cheek pad 70 is shown having four The hook and loop fastening system of VELCRO(™) arms 72 and a padded area 74 . The cheek pad 70 slips underneath the attaching end 16 . The padded surface of the cheek pad is towards the patient's cheek, thus facing down in this diagram. The four The hook and loop fastening system of VELCRO(™) arms are then folded at the dashed lines inwards on top of the attaching end 28 where they are coupled to the opposite The hook and loop fastening system of VELCRO(™) arm.
[0078] The advantage of the cheek pad in FIGS. 8A and 8B is that they are removable. However, it should also be apparent that the cheek pads could be constructed so as to be integral with the attaching ends.
[0079] It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention. The appended claims are intended to cover such modifications and arrangements. | A method and apparatus for providing an endotracheal tube holder which prevents injury to a neo-natal patient, including a flexible arcuate face plate, an tube holding member that is placed in the face plate in front of the patient's mouth, and an attachment mechanism which does not cause elastic compression on the neo-natal patient. A bite block is provided for preventing damage caused by the neo-natal patient biting on the endotracheal tube, the tube holding member is able to adjust to different sizes of endotracheal tubes to thereby hold them firm, an additional tube can be added for simultaneous access to the patient's mouth, cheek pads prevent injury to the patient's cheeks, and integral eye protection is provided on the attachment device. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 829,140 filed Aug. 30, 1977, abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to method for fertilizing leguminous plants.
2. Description of the Prior Art
Leguminous plants are characterized by their ability to fix nitrogen microbially from the atmosphere, usually in nodules connected with their root systems, and their ability to use the fixed nitrogen to produce proteinaceous seeds. The commercial products from leguminous plants are, in the main, seeds enclosed in true pods which are generated from the plants' flowers. Less than 10% of the flowers of the plant are normally converted to seed pods. Most flowers are aborted because of the inability of the plant to supply the nutrients required during period of stress when flowers are converted to mature seed pods among other reasons. Legumes constitute some of the world's most important agricultural crops; e.g., peas, beans, soybeans and peanuts.
Recent investigations have reported that foliar feeding of leguminous plants with liquid plant foods, when carefully applied, produces an increase in seed yields. Single or multiple applications of small amounts of aqueous plant foods containing urea, potassium polyphosphate and potassium sulfate have been purported to increase soybean yields significantly. Practical results, however, have been erratic and frequently poor because of foilage burn.
A number of chemical compositions containing water-insoluble nitrogen have been used as soil fertilizers to take advantage of the extended period of nitrogen release for the feeding of the root systems of plants. Some of the chemicals, previously reported for slow release of nitrogen for root fertilization include: isobutyl diurea, melamine, oxamide, urea-formaldehyde polymers, and others. Legume bearing plants fertilized with the foregoing compositions exhibit growth stimulation but improvement in pod production is not significant.
SUMMARY OF THE INVENTION
In accordance with the present invention formation of legume seed pods can be substantially increased by the application of a non-burning, nitrogenous plant food to the foliage of the leguminous plant during the flowering period. The amount of nitrogen applied in this manner is from about 0.3 to 2.0 percent based on the average weight yield of mature seeds obtained without applied fertilization. In addition to increasing seed pods, the practice of the invention results in the production of seeds of superior quality from the standpoint of yielding larger seeds having a higher proteinaceous content.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Essential to the practice of this invention is the use of a foliar plant food whose nitrogen content is assimilated by the foliage of plants at a rate or in a manner which does not burn or otherwise cause damage to the plant. Nitrogen can only be assimilated by a plant when in the form of a water-soluble compound. Accordingly, an effective foliar plant food in the context of this invention is principally composed of two components. One of these components is in the form of water-soluble organic nitrogen compounds so as to permit the feeding process to commence substantially immediately upon contact with the plant foliage. The other component is in the form of water-insoluble organic nitrogen compounds capable of progressively degrading to water soluble compounds under the influence of the urease and other enzymes and microbes present on the foliage.
Plant foods of the aforesaid type useful herein contain from about 25-50% of the total nitrogen content in the form of water soluble compounds and correspondingly from about 75-50% in the form of water-insoluble compounds. Water-soluble nitrogen in excess of the maximum indicated presents the hazard of foliage burn whereas a food containing less than about 25% of water-soluble nitrogen fails to promote flower conversion to pods to the optimum extent obtainable. Inorganic water soluble compounds can be used if present in a sparing amount so as to provide preferably not in excess of 10% of the total nitrogen content of the foliar feed.
Concentration of total nitrogen in the aqueous plant foods contemplated herein ranges from about 5-30% and more preferably in the order of from about 15-30%. While nitrogen serves as the primary nutrient in the practice of this invention, other nutrients such as potassium and phosphorous can optionally be employed in supplemental amounts. Particularly suitable sources of secondary nutrients are such as potassium phosphate and potassium polyphosphates. The phosphorous and potassium contents of foliar plant foods, when present, are customarily expressed in terms of an equivalent P 2 O 5 and K 2 O content, respectively. On this basis, phosphorous is ordinarily used not in excess of about 5% and generally from about 3-5% potassium is included in essentially the same amount. When present in about the indicated amounts, these secondary nutrients do not result in foliage damage.
As pointed out previously, the applicable plant foods consists essentially of a combination of water-soluble and water-insoluble organic nitrogeneous compounds. Illustrative of water soluble compounds are such as urea, the lower methylene ureas; e.g., methylene diurea, dimethylene triurea and trimethylene tetraurea, and the lower methylol ureas obtained by condensing urea with formaldehyde under appropriate processing conditions.
Representative water-insoluble nitrogen compounds include: isobutyl diurea, melamine, oxamide, the higher methylol urea condensates, and the higher methylene ureas such as trimethylene pentaurea and tetramethylene hexaurea.
The applicable plant foods can be conveniently prepared by blending the respective components to provide a composition conforming to the relative ratios hereinabove set forth. For economic considerations, however, an in situ method is preferred for preparing an applicable plant food whereby urea is condensed with formaldehyde under certain controlled conditions to provide a reaction product having the requisite contents of water-soluble and water-insoluble compounds. Irrespective of the manner utilized in obtaining the plant food, the water-insoluble compounds desirably have a particle size of not in excess of 0.1 mm and more preferably in the order of 0.01 mm or less. Larger size particles than the maximum indicated decompose slower than desired, cause spraying difficulties, and are prone to wash off the foliage before the plant can assimilate the available nitrogen to any significant extent.
A variety of in situ methods can be implemented in obtaining a foliar plant food useful herein. In one method urea is condensed with formaldehyde to provide a product wherein unreacted urea and the lower methylol derivatives constitute the water-soluble component and the higher methylol derivatives formed serve as the water-insoluble slow release source of nitrogen. A representative method of this type will be exemplified in the working examples presented hereinbelow. Additionally, the use of a product of the foregoing type which is commercially available in the form of a solid fertilizer composition will likewise be illustrated.
A singularly effective plant food for use in accordance with this invention is a commercially available clear aqueous concentrate of a ureaformaldehyde condensate containing about 26% nitrogen. The unique characteristic of this product is that it exhibits extended storage stability and yet upon application to the foliage of a plant or contact with the soil polymerization proceeds to occur thereby converting a proportion of the total nitrogen content to a water-insoluble form. The identity of the foregoing product and its use to fertilize a peanut crop in accordance with the present invention will be set forth in the examples to follow.
EXAMPLE I
To a jacketed reactor equipped with a stirrer and internal cooling coils were charged 4000 kg. aqueous formaldehyde (50%), 11800 kg. water and 6000 kg. urea (46% N).
The mixture was heated until all the urea was completely dissolved and heating was continued until the temperature reached 82° C. The pH of the solution was then adjusted to 3.5 by addition of 9 kg. of aqueous 25% formic acid. The temperature increased slightly to 85° C. and cooling water was applied to maintain the temperature for 45 minutes with constant stirring. At the end of this reaction period, the reaction mixture had a creamy appearance, and it was neutralized to pH 6.6 by the addition of 34 kilograms of triethanolamine and cooled to ambient temperature in 30 minutes. To the cooled mixture were added 680 kg. molasses, 37.5 kg. methanol and 170 kg. attapulgite clay. The mixture was then circulated through a high shear centrifugal pump for 30 minutes to gel the clay and to complete the blending of the added ingredients. A sample was withdrawn from the mixture and analysis for total nitrogen and water insoluble nitrogen showed 12.2% and 8.7%, respectively, indicating 71.3% of the nitrogen was water-insoluble.
EXAMPLE II
A field of English Peas in Delaware was estimated to yield, at harvest, about 570 kg. of peas per acre based on the stand of the legume plants and previous performance of the species in the area. Spraying of the suspension of 12-0-0 foliar feed of Example I was accomplished with a motorized back pack Stihl atomizer-blower, which produced a fine spray of foliar feed droplets uniformly less than 0.1 mm in diameter. Application was made at early flowering stage when flowers were still starting to form and at late flowering stage when some pods were starting to form. Comparisons were made of pod count of check plots and plots treated at early and late flowering stage. The results obtained are tabulated as follows:
TABLE II______________________________________Blossom Foliar Feed AverageStage Application Pea Pod VariationPlot at Rate Per Test fromNo. Application Kg./acre Count Check %______________________________________1 Late 100 58 + 382 Late 0 Check 42 --3 Early 200 58 + 294 Early 100 53 + 185 Early 0 Check 45 --______________________________________
As shown, the number of pea pods were significantly increased by the foliar treatment of the English Peas and that the treatment during the later part of the flowering stage produced a larger increase than the early flowering stage treatment. There was no evidence of foliar damage or burn from the foliar feed.
EXAMPLE III
To the urea-formaldehyde condensate suspension of Example I, was added potassium phosphate (containing 60% of the phosphate in the polyphosphate form) and water to produce a liquid suspension analyzing 10-3-3. A field of soybeans in Central Ohio was selected for foliar application. Based on the stand and previous years experience, anticipated seed yield was estimated to be 1090 kg. The above foliar feed suspension was applied by helicopter at the midbloom stage, and average droplet size was less than 0.1 mm in diameter as determined from test papers disposed in the treated area. Results obtained are tabulated as follows:
TABLE III______________________________________ Foliar Average Feed Bean Pod SoybeanPlot Blossom Application Count per YieldNo. Stage Kg./acre Plant Kg./acre______________________________________1 Middle 115 81 19002 Middle Check 45 980______________________________________
These data demonstrated that the number of soybean pods increased significantly when the soybean plants were foliarly fed at mid-flowering and that a 94% increase in the final soybean yield harvested over the check was obtained, although no additional fertilization was made after the mid-flowering treatment.
EXAMPLE IV
Two additional foliar feed samples were prepared from solid compounds containing water insoluble nitrogen and having the same 10-3-3 analysis used in Example III and these samples were tested in the same Central Ohio field on soybeans as noted in the previous example. Each sample was ground in a high speed hammer mill, screened to pass through a Tyler 100 mesh screen and then blended at ambient temperature with potassium ortho-phosphate, water, attapulgite clay, and 80 Brix molasses to produce the desired 10-3-3 composition. The sources of water insoluble nitrogen were: Hercules Powder Blue Nitroform Urea-formaldehyde analyzing 38% total nitrogen, 68% of which was water insoluble; and IBDU (isobutyl diurea) with 74% water insoluble nitrogen.
The test suspensions were applied from a "High-Boy" tractor using high pressure flood-type nozzles. Check plots and a plot using water soluble foliar feed, analyzing 10-3-3 and composed of urea, potassium polyphosphate, and potassium sulfate, were also included in the test. A single application was made to the foliage at the mid-flowering stage of the soybean plants. The plot treated with the water soluble foliar feed suffered leaf burn within 24 hours of treatment and the treated area had an overall yellow-brown appearance. The areas treated with the water insoluble suspensions retained a white sprayed appearance until the foliage was lost from frost. Estimated soybean seed production for the field was 1090 kg. per acre and treatment in all tests was made at the level of 8 gm. nitrogen per kilogram of anticipated seed production. The results of the tests are tabulated below:
TABLE IV______________________________________ % Soybean IncreasePlot Nitrogen % Yield OverNo. Source WIN Kg./acre Check______________________________________1 Check -- 980 --2 UF Polymer 68 1635 + 67 Powder Blue3 IBDU 74 1525 + 554 Urea 0 850 - 14______________________________________
The yield increases experienced in this test were slightly lower than those obtained in Example III with the "in-situ" generated urea-formaldehyde polymers, probably because the solids contained some polymers formed in the drying process which are extremely resistant to microbial degradation. As shown, the foliage burn on the soluble urea tests depressed the soybean yields.
EXAMPLE V
A field of Essex soybeans in Central Virginia was divided into test plots and was treated with the 10-3-3 foliar feed of Example III, prior to flowering, at mid-flowering, and at pod filling stage when the pods were approximately one-third filled. The treatments were made using a back-pack motordriven Stihl atomizer-blower which produced very fine drops. Pod counts were made and yields were obtained by hand-harvesting the crops after frost had dropped the leaves. Based on the stand and previous years experience the anticipated bean yield was 820 kilograms per acre. Application of the plant food was at a rate to provide 0.8% N based on said anticipated yield. The results of the experiments and average check are tabulated as follows:
TABLE V______________________________________ Per Cent Average Yield Bean Pod Soybean IncreasePlot Time of Count Yield OverNo. Application Per Plant Kg./acre Check______________________________________1 Check 38 1980 --2 Before 44 2200 + 11 Flowering3 Mid- 69 3850 + 94 flowering4 Pod-filling 42 2560 + 29______________________________________
Foliar treatment just before flowering caused the soybean plants to increase in growth rate significantly but did not substantially increase the number of bean pods formed, although some overall yield increase was obtained. Foliar treatment at the mid-flowering stage caused a dramatic increase in the conversion of flowers to seed pods and an increase in size of the individual beans as indicated by the 94% increase in bean yield. Treatment after the beanfilling process was under way still increased the yield of soybeans by increasing the size of the beans produced but did not have a large influence on the number of bean pods grown to maturity.
EXAMPLE VI
A field of Florigiant Peanuts in Central Virginia were treated with the foliar plant food of Example III. The anticipated production of peanuts was 1600 kilograms per acre and the field was treated at the rates of 0.1, 0.3, 1.0 and 2.0% nitrogen based on the estimated yield of peanuts. The foliar feed was applied by a hand-held high pressure atomizer to 0.01 acre plot at the late flowering stage when the peanut plants had begun to put pegs to the soil. The crop was carried to maturity, and the plants hand dug and the peanuts weighed. The results obtained are tabulated as follows:
TABLE VI______________________________________ Foliar Feed ApplicationPlot Rate Peanut Yield % IncreaseNo. Kg./acre Kg./acre over Check______________________________________1 Check 1685 --2 16 1660 - 23 48 2060 + 224 160 2190 + 305 320 2210 + 31______________________________________
EXAMPLE VII
Samples of the English Peas produced in Example II from the check plot and from the plot treated with the 12-0-0 plant food at late flowering stage, and samples of the soybeans produced in Example III from the check plot and from the plot treated with 10-3-3 plant food at mid-flowering stage were dried overnight in an oven at 80° C. and analyzed for total protein content. The results are tabulated as follows:
TABLE VII______________________________________ Amount IncreaseSam- of N Protein Fromple Type gm./kg. Time of Content, Check,No. Legume est. Seed Application % %______________________________________1 Peas Check -- 27.7 --2 Peas 0.02 Late Flowering 31.1 12.33 Soybean Check -- 41.9 --4 Soybean 0.01 Mid-flowering 45.2 7.8______________________________________
EXAMPLE VIII
In this example the foliar plant food utilized was a clear aqueous solution of urea-formaldehyde partial condensation product marketed under the trademark FORMALENE (Ashland Chemical Company) having an analysis of 26-0-0. The testing was conducted in a field of Florigiant peanuts in Central Virginia during the late flowering stage when "pegs" were starting to go from the plant into the soil. The application of the plant food was in the form of a fine spray which upon contact with the plants commenced to polymerize forming, for the most part, water-insoluble slow-releasing nitrogen compounds. Application rates observed in this test together with the results obtained are outlined as follows:
TABLE VIII______________________________________ ApplicationPlot Rate Peanut Yield % IncreaseNo. Kg./acre Kg./Acre Over Check______________________________________1 Check 1635 --2 26 2160 323 52 2225 364 68 2245 37______________________________________ | Method for the foliar feeding of leguminous plants wherein a nonburning nitrogenous plant food is applied to the foliage of the plant at a critical life-cycle period to increase substantially the quantity and to enhance the quality of seeds produced therefrom. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a combustion furnace for burning a sample to be analyzed.
2. Description of Related Art
It is well known that a sample can be analyzed by burning the sample in a furnace and analyzing the gaseous ingredients emitted. It is also well known that the combustion of the sample generates a large amount of dust. Cylindrical filters have been tried for removal of this residual dust. However, the dust generated by combustion still remains a problem. Additionally, burning agents such as tungsten and tin, which may be added to promote the extraction of ingredients from the sample, increase the quantity of dust generated.
The quantity of dust generated by combustion of the sample creates problems in the system. The dust sticks to the filter, as well as to the internal areas of the combustion chamber, creating problems in that the filtration effect of the filter is lowered. Moreover, the extracted ingredients to be analyzed are adsorbed by the dust, thus lowering the accuracy of the analysis.
Accordingly, combustion furnaces for the burning of samples have been provided with a device for removing the dust stuck to inner surfaces of the filter and the furnace, as shown in FIG. 3.
FIG. 3 shows a conventional furnace for analyzing the ingredients of a sample. The furnace has a body 31 and a combustion cylinder 32 provided in the body 31. A heater 33 used for high-frequency heating is located on the periphery of a combustion cylinder 32. A crucible 34, which contains a sample to be analyzed, is placed on a holding member 35. A cylindrical filter 36 is arranged in a manner that permits the ingredients to be analyzed to travel from the combustion cylinder 32 to the outlet port 39. A cleaning rod 37 is provided that reciprocally slides and rotates in a circumferential direction within the filter 36 and the combustion cylinder 32. The cleaning rod 37, which is also used as a lance, is provided with a brush 38 mounted on an end for cleaning inner surfaces of the filter 36 and the combustion cylinder 32. A heating member 40 is provided for heating the filter 36.
In this prior art combustion furnace, the crucible 34, with the sample inside, is inserted into the combustion cylinder 32. The combustion cylinder 32 is heated by means of the heating member 33 to the point of burning the sample. The gaseous ingredients emitted are passed through the filter 36 and sent to an analyzer (not shown) through an outlet line (not shown) connected to the outlet port 39. The brush 38 is located in an upper portion inside the combustion cylinder 32 during the combustion of the sample. Dust generated by the combustion sticks to the inner surface of the combustion cylinder 32 and the filter 36.
The dust can then be removed by means of the brush 38 mounted on the end portion of the cleaning rod 37 by reciprocally sliding and rotating the cleaning rod 37 manually or by the use of a motive power (motor and the like).
The removal of the dust in the conventional combustion furnace, carried out by moving the brush 38 by means of the cleaning rod 37, presents problems. First, considerable labor is required. Second, the construction is complicated. Also, since only the inner circumferential surface of the filter 36 is scrubbed with the brush 38, it is difficult to remove the dust on an inside filament layer of filter 36. Thus, most probably part of the dust will not be removed by this method. Furthermore, since the surface of the filter 36 is varied by cleaning with the brush, repeated analysis of the waste ingredients is required.
An additional problem is presented by the fact that the brush 38 is always located within the combustion cylinder 32. This considerably complicates the construction of the interior of the furnace.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a combustion furnace that allows for removal of all the dust that is stuck to the filter and the interior of the furnace, while still retaining a simple structure.
A combustion furnace for burning a sample to be analyzed, having a cylindrical filter arranged so as to communicate gaseous ingredients between a combustion cylinder and the outlet port, is provided by a cleaning gas supply line which supplies the inside of the furnace with a cleaning gas through a gas port in the furnace body. The gas port is formed on the outer circumferential portion of the filter. Cleaning gas is sent to the inside of the furnace under pressure when it is necessary to remove dust from the filter and the interior regions of the furnace.
The gas port can also be used for removing the gas to be analyzed from the inside of the furnace. In this case, the cleaning gas supply line converts to a line for removing the gas to be analyzed by means of a switchover valve. In the alternative, the gas port for removing the gas to be analyzed and the gas port for supplying the cleaning gas can be separately provided.
With this combustion furnace, the sample is burned in the combustion cylinder. The gas to be analyzed is sent to an analyzer through the filter. The cleaning gas, such as O 2 , for example, is sent into the body of the furnace under pressure through the cleaning gas supply line. It removes the dust that is stuck to the filter and the combustion cylinder. The cleaning gas is passed through the outside of the filter to the inside of the filter in order to separate the dust that is stuck to the filter and inner surfaces of the furnace. The pressure under which the cleaning gas is administered forces loose the dust particles stuck to the inside of the furnace. The cleaning gas may be continuously or intermittently applied. If the cleaning gas is applied intermittently by fluctuating the pressure of the gas, the dust-removing effect is improved.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing a preferred embodiment of the present invention;
FIG. 2 is a partially sectioned front view showing another preferred embodiment of the present invention; and
FIG. 3 is a sectional view showing a conventional prior art furnace.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description is provided to enable any person skilled in the furnace industry to make and use the invention, and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the arts, since the generic principles of the present invention have been defined herein specifically to provide a relatively easily manufactured combustion furnace for use in analyzing samples.
The preferred embodiment of a combustion furnace for burning samples to be analyzed according to the present invention is described with reference to FIG. 1. In this preferred embodiment, a gas port or outlet part 5 for taking out the gas to be analyzed is also used for supplying a cleaning gas.
Referring now to FIG. 1, reference numeral 1 designates the body of a furnace having a combustion cylinder 2 provided within the body 1 of the furnace. A heating member 3 employing high-frequency heating is contained on an outer circumference of the combustion cylinder 2. A cylindrical filter 4 is disposed on a downstream side of the combustion cylinder 2 so that gases to be analyzed travel between the combustion cylinder 2 and an outlet port 5.
Outlet port 5 is formed on the body 1 of the furnace at an outer circumferential portion of the filter 4 to provide for the removal of the gas to be analyzed. A filter case 6, filled with quartz wool and the like, forms a subfilter 7. It is mounted on the body 1 of the furnace in order to communicate the gases to the outlet port 5. The filter case 6 has a cover 8. A connection pipe 9 is connected to the filter case 6 to allow the gas from the inside of the filter case 6 to flow to the analyzer 10 through a three-way valve 11 and pipe 12.
A cleaning-gas tank 13 of oxygen and the like, used for cleaning the filter 4, is connected with the three-way changeover valve 11 through a cleaning pipe 15 to create a cleaning-gas supply line 16.
A sample crucible 17 is mounted on an end of a holding member 18 and inserted into the combustion cylinder 2 through an inserting port 19 in the body 1 of the furnace. A dust-receptor 20 is disposed within the body 1 of the furnace for housing dust falling from the combustion cylinder 2. A guide rod 21 is fixedly mounted on the dust-receptor 20 at an end thereof and projects out of the body 1 of the furnace. This arrangement with the sliding of the guide rod 21 makes it possible for the dust-receptor 20 to be located below and on the side of combustion cylinder 2 during insertion of the crucible 17 into the combustion cylinder 2.
A dust-exhausting port 22 is formed on the bottom of the dust-receptor 20. A bellows-like flexible suction hose 23 is attached to the dust-exhausting port 22 and then connected to a suction device 24, such as a vacuum cleaner. The dust in receptor 20 may thus be taken out of the dust-receptor 20 by the suction device 24.
A heating member 25 is mounted on the body 1 of the furnace on a circumferential portion of the filter 4 for heating the filter 4. This prevents the gas to be analyzed from being adsorbed. Reference numeral 26 designates a cover for the body 1 of the furnace. P designates a lance passing through the cover 26 and through the center of filter 4.
Burning a sample in a combustion furnace having the above-described construction will now be described. The three-way changeover valve 11 is closed on the side of cleaning pipe 15. The holding member 18 is taken out of the body 1 of the furnace. A sample and any assistant combustion agent are placed in the crucible 17. The crucible 17 is inserted into the combustion cylinder 2. The heating member 3 is activated to heat and burn the sample. The gas generated from combustion of the sample passes through the filter 4 and the subfilter 6 into the analyzer 10 through the pipe 12.
After the combustion, in order to remove the dust stuck to an inner surface of the combustion cylinder 2 and the filter 4, the three-way changeover valve 11 is closed on the side of the analyzer 10. The crucible 17 is removed together with the holding member 18. The guide rod 21 is then adjusted, thereby positioning the dust-receptor 20 below the combustion cylinder 2, as shown by an imaginary line.
A cleaning gas from the cleaning-gas tank 13 is sent into the body 1 of the furnace under pressure through the cleaning pipe 15, the pipe 12, the subfilter 6, and the gas port 5.
Since the cleaning gas sent into the body 1 of the furnace is under pressure, dust stuck to the filter 4 is separated when the gas passes through the filter walls and enters the interior of the filter. The separated dust falls into the dust-receptor 20. The pressurized cleaning gas which has passed through the filter 4 also separates the dust that has stuck to the inner surface of the combustion cylinder 2 when it passes through the combustion cylinder 2. All the dust which has then been deposited in the dust-receptor 20 is then removed by the suction device 24 through the suction hose 23.
If the position of the three-way changeover valve 11 is fluctuated over a short time, for example, about 0.3 to 0.5 seconds, the fluctuation in the valve causes a resultant fluctuation in the pressure of the cleaning gas causing the filter 4 to vibrate, thereby more effectively separating dust that is stuck to the filter 4.
Since the cleaning gas is passed through the outside of the filter 4 to the inside of the filter 4, not only is the dust stuck to the surface removed, but the dust within the internal filament layers of the filter 4 is also removed.
Accordingly, the adsorption influence that the dust has on the gas to be analyzed is eliminated by the elimination of this internal filter dust.
FIG. 2 shows principal parts in another preferred embodiment. The, gas port 5 for taking out the gas to be analyzed and a gas port 27 for supplying the cleaning separately formed.
The gas port 27 is formed in the body 1 of the furnace for supplying the cleaning gas. A connection pipe 28 connects the gas port 27 with a cleaning gas tank 13 through a closing valve 11a and a cleaning pipe 15, to construct a cleaning gas supply line 16. An analyzer 10 is connected by a connection pipe 9 to a filter case 6 through a pipe 12.
Since the other structures are the same as in the preferred embodiment shown in FIG. 1, they are marked with the same reference numerals as in the preferred embodiment of FIG. 1.
In this second preferred embodiment, a gas to be analyzed is sent to the analyzer 10 from a gas port 5 through the pipe 12. To remove the dust stuck to a filter 4, a pump (not shown) is operated to send gas under pressure from the cleaning gas tank 13 to the inside of the body 1 of the furnace through the gas port 27. If a fluctuation of pressure in the cleaning gas supplied to the body 1 of the furnace is desired, this may be obtained by the repeated closing and opening of valve 11a.
According to the combustion furnace as described above in connection with FIG. 2, the cleaning gas is sent to the interior of the furnace under pressure through the gas port formed on the circumferential portion of the body of the furnace adjacent to the filter 4 when it is intended to remove the dust stuck to the cylindrical filter 4. The cleaning gas supplied to the body of the furnace is passed through the filter 4 from its outer circumferential area to its interior, thereby loosening the dust stuck to the filter and to the interior of the furnace.
In this way, not only is the dust stuck to the surface of the filter virtually completely removed, but the dust stuck to the internal filament layers of the filter is also removed. Thus, virtually all the dust stuck to the filter is removed. As a result, the accuracy of analysis is increased due to the virtual complete elimination of the dust. Adsorption of the gas to be analyzed by the dust left in the filter is thus prevented. | A combustion furnace having a cylindrical filter arranged to pass gases between a combustion cylinder and a gas analyzer attached to an output port on the furnace. The gases to be analyzed are generated from a sample burned in the combustion cylinder and removed through the filter. A cleaning gas supply port and supply line for supplying a cleaning gas to the inside of the furnace are provided. The cleaning gas is under pressure and may be oscillated to assist in the removal of dust stuck to the filter and the interior of the furnace. The improved dust removal provides for a much cleaner furnace and a more accurate analysis of the sample. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to a fuel injection pump for a diesel engine, and more particularly relates to a type of diesel fuel injection pump in which the injection of fuel can be cut off by a fail safe mechanism if discontinuity or abnormality in an electromagnetic valve for fuel injection amount control is detected.
In a diesel engine, the diesel fuel is injected at high pressure by a diesel fuel injection pump through fuel injectors into the cylinders of the engine in turn upon their compression strokes, and ignites due to the natural compression in the cylinders and is combusted therein without any special electrical or mechanical ignition means being required. Therefore in such a diesel engine there is a risk that if the fuel injection pump develops some abnormality the injection of fuel may be performed to too great an extent. For example, the injection of fuel may be performed in an amount corresponding to full engine load, even when the load on the engine is less than full load; or, worse, the injection of fuel may be continued to be performed, even when it is desired to completely terminate fuel injection and to stop the diesel engine running. In such a case, the danger arises of the diesel engine overrunning or overrevving, and this type of malfunction can be very troublesome.
There is known a type of fuel injection pump for a diesel internal combustion engine which includes a plunger which reciprocates to and fro in a bore defined in a housing, a high pressure chamber being defined between one end of the plunger and the end of the bore. During the suction stroke of the plunger as this high pressure chamber expands in size, diesel fuel is sucked into this high pressure chamber from a quantity of diesel fuel contained in a relatively low pressure chamber through a fuel supply passage; and during the compression stroke of the plunger as the high pressure chamber subsequently contracts in size, this diesel fuel in the high pressure chamber is squeezed and is brought to a high pressure and is ejected through an injectionn passage therefor to a fuel injector of the diesel internal combustion engine. Sometimes, in the case that the diesel fuel injection pump is a so called distribution type pump, the plunger is rotated as it reciprocates by an input shaft which is rotationally coupled to it although not axially coupled to it, and by a per se well known construction the spurt of highly compressed diesel fuel is directed to the appropriate one of the plurality of cylinders of the internal combustion engine. Now, such a fuel injection pump injects an amount of diesel fuel in each pump stroke which is regulated by a fuel injection amount control means which selectively vents the high pressure chamber. This control means ceases to vent the high pressure chamber when it is appropriate to start the fuel injection spirt, during the compression stroke of the plunger, and at this instant the almost incompressible diesel fuel in the high pressure chamber starts to be squeezed and injected, as explained above. When it is appropriate to terminate the fuel injection spirt, then the control means starts again to vent the high pressure chamber, and at this instant the diesel fuel in the high pressure chamber ceases to be squeezed and therefore the injection is immediately stopped.
In the case of a mechanical diesel fuel injection pump, it has been conventional for this high pressure chamber selective venting means to be a spill ring, which is mechanically positioned according to the position of the accelerator pedal which is controlling the load on the engine, and whose position controls the timing instant of the end of the non-vented time period of the high pressure chamber. In such a mechanical type of fuel injection diesel pump, it is very rare for such a malfunction to develop as that the venting of the high pressure chamber should fail, because of the simple structure of the spill ring construction, and because of the fact that typically the accelerator pedal simply positions the spill ring through a simple linkage, and in such a construction there is no very important requirement for a system to prevent engine overrunning of the sort described above. However, in a more sophisticated mechanical type system of this sort, in which the linkage between the position of the accelerator pedal and the position of the spill ring is not a simple mechanical one but is, for example, performed electronically, it has been known to compare the required fuel injection amount with the actual position of the spill ring and to interrupt fuel injection if they do not agree, at least to within some prescribed margin of error.
However, nowadays electronically controlled fuel injection pumps are coming into use, in which the selective venting of the high pressure chamber is performed, not mechanically by the use of a spill ring, but electronically by an electromagnetic valve which is controlled by an electronic control system such as one incorporating a microcomputer. In such an electronic fuel injection pump, the electronic control system, for each spirt of fuel injection, calculates how much fuel is to be injected in this spirt, and then at an appropriate time point for the start of fuel injection closes said electromagnetic valve, so as to terminate fuel spilling from the high pressure chamber and so as thereby to start fuel injection. After the electronic control system has calculated that the proper amount of fuel has been injected by the movement of the plunger in the direction to reduce the size of the high pressure chamber, then said control system opens said electromagnetic valve for fuel spilling again, thus immediately terminating fuel injection. In such an electronic type of fuel injection pump, since there exists no spill ring, such a comparison of the required fuel injection amount with the actual position of the spill ring is of course impossible, and accordingly some other method is required for preventing engine overrunning. Also, because the control valve that regulates the amount of fuel spilled from the high pressure chamber and the timing of such spilling is an electromagnetic valve, there is a quite significant risk of malfunction of such a valve.
Specifically, it is often the case that the electromagnetic valve for fuel spilling is an electrically activated valve of the type that is open when supplied with electrical energy and is closed when not supplied with electrical energy, i.e. functions so as to vent the high pressure chamber when supplied with electrical energy and functions so as not to vent the high pressure chamber when not supplied with electrical energy. A typical type of malfunction of such an electromagnetic valve is for the solenoid coil thereof to become discontinuous, so that its electromagnetic function is impaired or completely destroyed. If this occurs, then no fuel spilling from the high pressure chamber will occur at all, since the electromagnetic valve for fuel spilling is always closed, and this will mean that diesel fuel will always be injected to the combustion chambers of the diesel engine to the maximum amount, causing definite running away of the engine. The risk of this overrevving and runaway operation of the engine makes the provision of a means for detecting such malfunction of the electromagnetic valve for fuel spilling very important, as well as making it important to provide a means for controlling the diesel engine in such an eventuality.
SUMMARY OF THE INVENTION
Accordingly, it is a primary object of the present invention to provide a diesel fuel injection pump, which has a reliable means for detecting disconnection or abnormality of the solenoid coil of an electromagnetic valve for fuel spilling of the type described above.
It is a further object of the present invention to provide such a diesel fuel injection pump, which can detect when disconnection or abnormality of the solenoid coil of an electromagnetic valve for fuel spilling have occurred, and which interrupts fuel injection in such a case.
It is a further object of the present invention to provide such a diesel fuel injection pump, which can detect disconnection or abnormality of the solenoid coil of an electromagnetic valve for fuel spilling, and which completely and definitely stops operation of the diesel engine in such a case.
It is a further object of the present invention to provide such a diesel fuel injection pump, which can detect disconnection or abnormality of the solenoid coil of an electromagnetic valve for fuel spilling, and which curbs the operation of the diesel engine in such a case.
It is a further object of the present invention to provide such a diesel fuel injection pump, which can detect disconnection or abnormality of the solenoid coil of an electromagnetic valve for fuel spilling, and which puts a maximum on the revolution speed of the diesel engine in such a case.
It is a further object of the present invention to provide such a diesel fuel injection pump, which can detect disconnection or abnormality of the solenoid coil of an electromagnetic valve for fuel spilling, and which in such a case still allows of emergency running of the diesel engine while preventing any catastrophic running away thereof.
It is a further object of the present invention to provide such a diesel fuel injection pump, which reliably prevents engine overrunning and overrevving.
It is a further object of the present invention to provide such a diesel fuel injection pump, which is fail safe.
According to the most general aspect of the present invention, these and other objects are accomplished by, for a diesel engine comprising cylinders and a crankshaft: a fuel injection pump, comprising: (a) an input shaft which is rotated in a predetermined phase relationship with said crankshaft; (b) a housing and a plunger which slides in a bore formed in said housing and is coaxial with said input shaft, a high pressure chamber being defined at an end of said plunger between it and said bore, and another end of said plunger being rotationally engaged with said input shaft but being free to move axially with respect thereto; (c) a means for communicating said high pressure chamber to inject fuel into one or another cylinder of said diesel engine, according to the rotational position of said plunger, substantially only when said plunger is axially moving so as to reduce the size of said high pressure chamber; (d) an electrically actuated electromagnetic valve, comprising a solenoid coil, which selectively vents said high pressure chamber; (e) a means for selectively actuating and deactuating said electromagnetic valve, so as to provide fuel injection in appropriate amount to said diesel engine; (f) a means for determining whether or not the voltage across said solenoid coil of said electromagnetic valve, when said means for selectively actuating and deactuating said electromagnetic valve deactuates said electromagnetic valve from its actuated condition, rises higher than a certain value, or not; (g) a means for restraining said diesel engine; and (h) a means for actuating said means for restraining said diesel engine if said determining means detects that said voltage across said solenoid coil of said electromagnetic valve when it is deenergized from the energized condition has not risen to higher than said certain value.
According to such a structure, the diesel engine is restrained, when the means for doing so determines that the voltage across the solenoid coil has not risen to greater than said certain value, when said solenoid coil is deenergized. Such a lack of voltage rise, in other words an absence of high voltage transient spike caused by self inductance of the solenoid coil, is taken as indicating that the solenoid coil has failed by becoming discontinuous, or in some other way has started to function abnormally, and according to this the operation performed by the present invention as outlined above of restraining the diesel engine means that the dangers of overrunning or overrevving of said diesel engine in such a failure condition are positively avoided. Thus, the diesel fuel injection pump is made to be fail safe.
Further, according to a more particular aspect of the present invention, these and other objects are more particularly and concretely accomplished by such a diesel fuel injection pump as described above, wherein said means for restraining said diesel engine completely cuts off operation of said diesel engine when actuated; and this may be done by providing a valve for cutting off supply of fuel to said high pressure chamber in such an event.
According to such a structure, the diesel engine cannot be operated at all, when failure or abnormality of the solenoid coil are detected; and thus the fail safe operation of this specialization of the present invention is absolutely assured.
Further, according to a more particular aspect of the present invention, these and other objects are more particularly and concretely accomplished by such a diesel fuel injection pump as described above, wherein said means for restraining said diesel engine restricts the rotational speed of said diesel engine to less than a certain ceiling value, when actuated; and this may be done, said diesel engine further comprising an intake system, by providing a means for restricting the flow of intake air through said intake system, when actuated.
According to such a structure, the diesel engine can still be operated at low rotational speed, in other words in a limping emergency mode, when failure or abnormality of the solenoid coil are detected; and thus it becomes possible for the operator of a vehicle incorporating the engine to slowly bring the vehicle to a service facility, for example.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be shown and described with reference to the preferred embodiments thereof, and with reference to the illustrative drawings. It should be clearly understood, however, that the description of the embodiments, and the drawings, are all of them given purely for the purposes of explanation and exemplification only, and are none of them intended to be limitative of the scope of the present invention in any way, since the scope of the present invention is to be defined solely by the legitimate and proper scope of the appended claims. In the drawings, like parts and features are denoted by like reference symbols in the various figures thereof, and:
FIG. 1 is a sectional longitudinal view, in part 90° expansion, of the first preferred embodiment of the diesel fuel injection pump of the present invention, also showing a section of the diesel engine to which it is fitted, and an accelerator pedal and a driver's foot therefor;
FIG. 2 is a diagrammatical view of a microcomputer and of associated electrical circuitry, incorporated in the control system of this first preferred embodiment;
FIG. 3 is a flow chart showing a main fuel injection control routine stored in said microcomputer;
FIG. 4 is a flow chart showing a spike interrupt subroutine stored in said microcomputer;
FIG. 5 is a flow chart showing a discontinuity detection interrupt subroutine stored in said microcomputer;
FIG. 6 is a flow chart showing a fail safe subroutine stored in said microcomputer;
FIG. 7 is a timing chart, showing in its FIG. 7a a spike of induced voltage across the solenoid coil of an electromagnetic solenoid valve for fuel spilling, and in its FIG. 7b the changing of a control signal for said solenoid valve from ON to OFF which caused said voltage spike;
FIG. 8 is a sectional longitudinal view, similar to FIG. 1 and also in part 90° expansion, of the second preferred embodiment of the diesel fuel injection pump of the present invention, and similarly also showing a section of the diesel engine to which it is fitted, said diesel engine particularly having a venturi in its intake manifold, and also showing an accelerator pedal and a driver's foot therefor;
FIG. 9 is a diagrammatical view, similar to FIG. 2, of a microcomputer and of associated electrical circuitry, incorporated in the control system of this second preferred embodiment; and
FIG. 10 is a graph, showing engine revolution speed along the horizontal axis and fuel injection amount per unit injection stroke of the fuel injection pump along the vertical axis, in three different throttling conditions of the intake system of the engine.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described with reference to the preferred embodiments thereof, and with reference to the appended drawings. Referring to FIG. 1, which shows the first preferred embodiment, this diesel fuel injection pump 1 is an electromagnetic spilling type distribution type fuel injection pump, and comprises a drive shaft 2 adapted to be driven by a crankshaft, not particularly shown, of a diesel engine, which is partially shown in sectional view in the figure, in a predetermined phase relationship thereto. The diesel engine to which the exemplary first preferred embodiment is to be fitted is in fact a four cylinder four stroke diesel engine. The drive shaft 2 drives a vane type feed pump 4 (shown in a plane section in FIG. 1 which is at 90° to the general plane of the figure), which feeds diesel fuel supplied via a fuel supply connection 54 and, by the control of a venting pressure control valve 58, under a moderate pressure (which is representative of the rotational speed of said vane pump 4 and thus of the rotational speed of the drive shaft 2 and of the diesel engine) through a passage 59 to a large fuel chamber 30 defined within the housing 24 of the fuel injection pump 1, fuel in said large fuel chamber 30 being vented, when appropriate, via a fuel return connection 56 incorporating a proper orifice passage. The drive shaft 2 has mounted at an intermediate position on it a signal rotor 6, having a plurality of teeth formed thereon, and is at its right end in the figure formed with a coupling shape 8. An electromagnetic pickup 60 is mounted to a roller ring 14 described later in the housing 24 opposing the teeth of the signal rotor 6 for producing electrical signals regarding the angular position of the drive shaft 2 when the teeth of said rotor 6 pass it. A generally cylindrical plunger 12 is mounted with its central axial line coincident with the central axis of the drive shaft 2, and its left end in the figure is formed in a coupling shape which fits together with the coupling shape 8 of the drive shaft 2 so that the plunger 12 is rotationally coupled to the drive shaft 2 while being free to move axially with respect thereto. The cylindrical right end in the figure of the plunger 12 is closely and cooperatingly fitted into a cylindrical bore formed in a boss portion 11 fitted in the pump housing 24 and can slide and rotate freely in said bore; and the plunger 12 is biased to the left in the figure by a compression coil spring 13 and a collar 13a fitted on a lange shaped portion 12a of the drive shaft 2 and associated spring receiving elements, etc.
A cam plate 10 is fixedly secured around the left hand end in the figure of the plunger 12 and rotates integrally therewith, and the left hand side of this cam plate 10 is formed in an axial circular cam shape bearing a plurality of convex and concave cam portions, the convex ones being designated in the figure by the symbol 10a. The roller ring 14, which as mentioned above supports the electromagnetic pickup 60, is rotatably mounted to the housing 24 of the fuel injection pump, around the coupling shape 8 and mutually concentric therewith, and is provided with a plurality of cam rollers 16 rotatably mounted along the outer circumferential part of its right hand side in the figure, bearing against the cam plate 10, with the central rotational axis of each of said cam rollers 16 extending radially perpendicular to the central axis of the drive shaft 2. The number of the cam rollers 16 and the number of the convex cam portions 10a are such that, as the plunger 12 and the cam plate 10 rotate through one full revolution with respect to the roller ring 14, the cam action of the cam portions 10a on the rollers 16 causes the plunger 16 to be reciprocated axially to and fro by the same number of times as the number of cylinders of the diesel engine. Thus, in the shown exemplary first preferred embodiment which is a fuel injection pump for a four cylinder diesel engine, there are provided four equally spaced cam rollers 16 and four equally spaced convex cam portions 10a (although some of both of these are not visible in the figure). The roller ring 14 is rotatably mounted to the pump housing 24, and its angular position is variably controlled with respect thereto by a timer 18, schematically shown in a plane section at 90° to the general plane of the figure, and this timer 18 comprises a timer piston 22 slidably mounted in a bore formed in the pump housing 24 and a pin 20 radially mounted to the roller ring 14 and engaged at its free end portion with the timer piston 22 so as to be rotationally turned and to rotationally position said roller ring 14. The timer piston 22 is biased in its rightwards axial direction in the figure as viewed in said 90° turned plane section by a compression coil spring 26 mounted between its left hand end in the figure and the corresponding end of its bore, and is biased in the leftwards axial direction by the output pressure of the vane pump 4, which is supplied via passages 57a and 57b to chamber 19 defined at the right hand end in the figure of said bore, in such a manner that the axial movement of the timer piston 22 leftward in the figure is representative of the rotational speed of the crankshaft of the engine, and drives the roller ring 14 to rotate it in the direction opposite to the rotational direction of the drive shaft 2 so as to advance the fuel injection timing by an amount determined by the output pressure of the vane pump 4, i.e. determined by the revolution speed of the crankshaft of the diesel engine. However, this basic fuel injection advancing is modified by the provision of an electromagnetic valve 248, which is connected so as selectively to release a certain amount of fuel from the chamber 19, according to selective control by a control system 62 which will be described later; this arrangement enables the control system 62 to alter the actual ignition timing to agree with a desired reference ignition timing.
On the right hand side in FIG. 1 of the fuel injection pump 1 there is mounted in the housing 24 a block 28, in which the aforementioned boss 11 is fitted. A fuel passage 32 leads from the large fuel chamber 30 to an intermediate fuel chamber 32a defined within the block 28, and a passage 44 leads from said intermediate fuel chamber 32a to a fuel supply port 44a which opens in the side surface of the cylindrical bore in the boss 11 in which the plunger 12 reciprocates. An electromagnetic valve 34 for fuel shutting off is provided, and a valve element 36 of this valve 34 is so constructed and arranged that: when the solenoid coil (not particularly shown) of the electromagnetic valve 34 is supplied with actuating electrical energy, its valve element 36 is moved upwards in the figures away from the upper end 36a of the passage 44, thus opening said upper end 36a and allowing communication between the passage 32 and the passage 44; but, on the other hand, when said solenoid coil of this electromagnetic valve 34 for fuel shutting off is not supplied with actuatig electrical energy, its valve element 36 is moved downwards by the action of a spring (likewise not particularly shown) towards said upper end 36a of the passage 44 and blocks it, thus interrupting communication between the passage 32 and the passage 44.
The outer cylindrical surface of the right hand end of the plunger 12 is formed with a plurality of axially extending grooves 42, which are equally spaced around said plunger 12 and reach its end and whose number is the same as the number of cylinders of the diesel engine and which are arranged sometimes one or other to coincide with the fuel supply port 44a, according to rotation and reciprocation of the plunger 12; and a central axial hole 52a is formed along the axis of said plunger 12, one end of said hole 52a opening to the right hand end surface of the plunger 12 and the other end of said hole 52a opening to a side notch port 52 provided on the outer cylindrical surface of an intermediate portion of the plunger 12. A plurality of delivery valves 48 in number the same as the number of cylinders of the diesel engine are mounted in the block 28 (only one of the valves 48 with its associated arrangements is shown in FIG. 1 for the purposes of simplicity), and the inlet of each of these delivery valves 48 is selectively supplied with diesel fuel via a passage 50 which leads to a fuel receiving port 52b which opens in the side surface of the cylindrical bore in the boss 11 in which the plunger 12 reciprocates; the ports 52b are equally spaced around the plunger 12 and also are in number the same as the number of cylinders of the diesel engine, i.e. are four in number in this shown first preferred embodiment. Each of the delivery valves 48 is connected via a high pressure fuel pipe to a fuel injector fitted in a corresponding one of the cylinders of the diesel engine, for supplying diesel fuel under high pressure thereto at an appropriate amount and timing. The side notch port 52 is arranged to sometimes coincide with one or other of the fuel receiving ports 52b, also according to rotation and reciprocation of the plunger 12.
A high pressure chamber 40 is defined between the right hand end of the plunger 12 and an electromagnetic valve for fuel spilling 38 fitted to the block 28 and closing the end of the cylindrical bore in the boss 11 in which said plunger 12 reciprocates, in cooperation with the cylindrical side surface of said bore, with the ends of the notches 42 and the end of the central hole 52a in the plunger 12 communicating to this high pressure chamber 40; and this electromagnetic valve for fuel spilling 38 regulates escape of fluid from the high pressure chamber 40. The fuel vent passage 46 of this electromagnetic valve for fuel spilling 38 is communicated, via an intermediate passage 45 formed in the boss 11, to the large fuel chamber 30.
The electromagnetic valve for fuel spilling 38 comprises a housing 103 in which the return passage 46 mentioned above is formed, and an iron core 107 is fitted in this housing 103 and has an electromagnetic coil 105 wound around it. A cylindrical bore 109 of relatively large diameter formed in the valve housing 103 has a cylindrical valve element 102 fitted therein so as to be reciprocable along the axis thereof. The valve element 102 has a relatively thin left hand end tip 106, which cooperates with a hole formed in a valve seat member 108 so as selectively to close or to open said hole, according as said valve element 102 is pushed thereagainst, or not, respectively. A compression coil spring 104 is fitted between the iron core 107 and the right hand end of the valve element 102, so as to bias the value element 102 leftwards as seen in the figure, against said hole in said valve seat member 108. The space to the right of the valve seat member 108 is communicated to the upstream end of the return passage 46, and the left side in the figure of the valve seat member 108 defines the right side of the high pressure chamber 40.
Thus, when no electrical energy is supplied to the coil 105, then the iron core 107 is not magnetized, and thus the compression coil spring 104 biases the valve element 102 leftwards in the figure, so that the end 106 thereof closes the hole in the valve seat member 108, and this seals off the high pressure chamber 40 from the return passage 46. On the other hand, when actuating electrical energy is supplied to the coil 105, then the iron core 107 is magnetized, and then against the biasing action of the compression coil spring 104 which is overcome the valve element 102 is pulled thereby rightwards in the figure, so that its end opens the hole in the valve seat member 108, and this opens a passage from the high pressure chamber 40 to the return passage 46, allowing a flow of fluid out from the pressure chamber 40 and depressurizing said pressure chamber 40.
The delivery valve 48 is connected, via a conduit 202, to a fuel injection valve 268 which is fitted to one of the cylinders of the diesel engine. In fact, in this exemplary construction, the fuel injection valve is fitted to a secondary combustion chamber 273 for this cylinder. Also to this secondary combustion chamber 273 is fitted a glow plug 270, projecting into said secondary combustion chamber 273.
Further, an accelerator pedal depression amount sensor 274 provides an electrical output signal representative of accelerator pedal depression amount, i.e. of engine load; an intake manifold pressure sensor 276 provides an electrical output signal representative of the pressure in the intake manifold of the diesel engine; a water temperature sensor 278 provides an electricasl output signal representative of the temperature of the cooling water of the diesel engine; and a glow relay 280 controls supply of electrical energy to the glow plug 270. The electrical output signals of the sensor 62 of the fuel injection pump 1, of the accelerator pedal depression amount sensor 274, of the intake manifold pressure sensor 276, and of the water temperature sensor 278, are fed into a microcomputer incorporated in a control circuit 62 for the fuel injection pump 1; and the glow relay 280 and the solenoids of the electromagnetic valve for fuel spilling 38, of the electromagnetic valve 248 for timing control, and of the electromagnetic valve 34 for fuel shutting off are fed from an output port construction of said microcomputer.
The internal construction of this microcomputer is schematically shown in FIG. 2. This microcomputer has a central processing unit (CPU) 82A, a read only memory (ROM) 82B, a random access memory (RAM) 82C, a back up random access memory (BU-RAM) 82D, and I/O port 82E, an analog/digital converter (ADC) 82F, and a bus which interconnects these elements, and so on; and the control circuit 62 also includes a drive circuit 82G and transistor 82H. The analog/digital converter 82F converts the analog output signals from the accelerator pedal depression amount sensor 274, the intake manifold pressure sensor 276, and the water temperature sensor 278 into digital signals under the control of the CPU. The read only memory (ROM) has permanently stored in it a control program concerning fuel injection amount and so on, which includes several subroutines which will be described later, as well as various constants and other data, including a table of fuel injection timing (or spill angle) as determined from fuel injection amount and engine rotational speed, as will be explained in more detail shortly. The control circuit 62, as a whole, performs control of fuel injection amount and other matters according to these signals as will be described hereinafter, by supplying control electrical signals to the electromagnetic valves 34, 248, and 38, as well as to the glow plug relay 280 for controlling the glow plug 270. The output signal from the sensor 60, which already is of a digital nature, is fed directly to the I/O port 82E. This I/O port 82E outputs control signals to the electromagnetic valves 34 and 248, and to the relay 280, and also supplies an ON/OFF signal for controlling the electromagnetic valve 38 for fuel spilling, i.e. a fuel injection amount control signal, to the input of a drive circuit 82G, the output of which is fed to the base of the transistor 82H. The emitter of the transistor 82H is connected to ground, and the collector of this transistor 82H is connected to the solenoid coil 105 of the valve 38 via a resistor R. A voltage signal is fed back from the collector of the transistor 82H to the I/O port 82E, in order for the microcomputer to have information of the actual voltage being applied across the coil 105 of the valve 38 for fuel spilling; the use of this will become apparent later.
Now, the action of this fuel injection pump 1 during operation of the diesel engine will be described. When the engine is running and the crankshaft (not shown) of said engine is rotating, the drive shaft 2 is rotated in synchrony therewith and at a predetermined phase in relation thereto (actually at half crankshaft speed, because this is exemplarily a pump for a four stroke diesel engine), and drives the vane pump 4, and fuel pressurized to the output pressure of said vane pump 4, which is representative of the rotational speed of said drive shaft 2 and of said crankshaft of the engine, is fed into the chamber 30 and into the fuel passages 32 and 44 and also into the actuating chamber 19 of the timer assembly 18, so as to cause the timer piston 22 to be driven leftwards in the figure (90° plane section) by an amount corresponding to said rotational speed of said engine, thus rotating the roller ring 14 and the rollers 16 mounted thereon by a similarly corresponding amount from their starting rotational positions relative to the housing 24 in the direction opposite to the rotational direction of the drive shaft 2. Meanwhile, as the drive shaft 2 and the plunger 12 rotate in synchronism with one another, and as the cam plate 10 is also rotated, the cam projections 10a are caused to ride up and down the rollers 16, so as to reciprocatingly drive the plunger 12 against the biasing force of the compression coil spring 13 leftwards and rightwards in the figure at appropriate timing governed by the aforesaid rotational position of the roller ring 14, as said plunger 12 also rotates, i.e. according to the rotational speed of the diesel engine, with the plunger 12 making one complete rotation for every two rotations of the crankshaft of the diesel engine, in this exemplary case of a four stroke type diesel engine. While the master running or ignition switch of the vehicle is turned on while the diesel engine is running normally, actuating electrical energy is being supplied to the electromagnetic valve 34 for fuel shutting off, and so its valve element 36 is displaced from the valve seat 36a and the fuel passage 32 is in communication with the fuel passage 44. Therefore, on each of the suction or leftward strokes of the plunger 12 when one of the notches 42 is corresponding to the fuel supply port 44a which opens in the side surface of the cylindrical bore in the boss 11, diesel fuel at relatively low pressure is sucked into the high pressure chamber 40 from the chamber 30 through said fuel passages 32 and 44.
When thereafter the plunger 12 moves rightwards during its subsequent compression stroke, by the rotation of said plunger 12 said one of the notches 42 is no longer corresponding to the fuel supply port 44a, and accordingly back flow of diesel fuel to the passage 44 is prevented; and also the side notch port 52 is now coinciding with an appropriate of the fuel receiving ports 52b, also according to rotation of the plunger 12, so as to direct diesel fuel which is now being compresed in the high pressure chamber 40 by the rightward movement of the plunger to the appropriate one of the fuel delivery valves 48, via the hole 52a and said side notch port 52, so as to be injected into the appropriate cylinder of the engine via the relevant fuel injection valve 48, according to the per se well known distribution function of this fuel injection pump. However, this compression process of the diesel fuel within the high pressure chamber 40, and the injection thereof through the fuel delivery valve 48, only will take place if the coil 105 of the electromagnetic valve for fuel spilling 38 is not being provided with actuating electrical energy and thus said valve 38 is closed and is preventing communication between the high pressure chamber 40 and the vent passage 46. On the other hand, when actuating electrical energy is provided to said coil 105 of the valve 38, then the tip of the valve element 102 thereof is displaced from the hole in the valve seat member 108 as explained above, thus opening said hole, and thereby the high pressure chamber 40 is communicated with the vent passage 46, thus venting the compressed diesel fuel in the chamber 40 back to the large fuel chamber 30 to which said vent passage 46 communicates, and thereby cutting off fuel injection. During normal running of the diesel engine, the control circuit 62 supplies actuating electrical energy to the electromagnetic valve for fuel spilling 38 at an appropriate timing point during each fuel injection stroke of the plunger 12, so as to open said valve 38 and to cut off further fuel injection during this plunger stroke, according to the various signals regarding engine operational parameters which said control circuit 62 receives from its various sensors described above, as will shortly be described: this is how the amount of fuel injectingly supplied to the diesel engine, and thereby the load on said diesel engine, is controlled. This action of the control circuit 62 in venting the high pressure chamber 40 at an appropriate timing point is analogous to the operation of a spill ring in a conventional type of diesel fuel injection pump. When the diesel engine is running and it is desired to stop it from running, the master running switch of the vehicle is turned off by the operator, and this immediately causes stopping of supply of electrical energy to the electromagnetic valve 34 for fuel shutting off, so that its valve element 36 is moved against the valve seat 36a by the force of its biasing spring (not particularly shown) and communication between the fuel passage 32 and the fuel passage 44 is interrupted. Therefore, supply of new fuel to the diesel engine is terminated, and accordingly quickly the diesel engine comes to a halt.
Now, how the microcomputer incorporated in the control circuit 62 determines the amount of fuel to be injected in each injection spirt to each cylinder of the engine, in other words how said microcomputer determines the time for energizing the electromagnetic valve 38 for fuel spilling so as to terminate each spirt of fuel injection, and also how this microcomputer controls the electromagnetic valve 34 for fuel cutoff in order to provide a fail safe function for the diesel engine in the case of malfunctioning of the fuel injection pump occasioned by discontinuity of the electromagentic coil 105 of the electromagnetic valve 34 for fuel shutting off, will be particularly described, with reference to the flow charts of FIGS. 3, 4, 5, and 6.
FIG. 3 shows the flow chart of the main fuel injection control program of this microcomputer. In the step 100 of this program, from the engine rotational speed NE as calculated from the output signal of the sensor 62 and from the accelerator pedal opening amount ACCP as detected by the accelerator pedal opening amount sensor 274 the basic fuel injection amount Q is calculated in the following way. In idling range, the fuel injection amount QIDLE=KI-NE/KIC, where KI=1.75×ACCP+79.0, and KIC=10. And in partial and total load ranges, the fuel injection amount QPART=KPA-NE/KPB, where, if ACCP is between 0% and 20%, KPA=1.56×ACCP+20 and KPB=1.94×ACCP+50, while, if ACCP is between 20%, and 100%, KPA=1.314×ACCP+45 and KPB=2.18×ACCP+45.2. Thus, this program step 100 serves as a fuel amount computing means.
Then, in the step 102 of the program, corresponding to the current engine rotational speed NE and the desired fuel injection amount Q, a spill angle THETA is calculated, by interpolation from a table of THETA against engine rotational speed NE and desired fuel injection amount Q stored in the ROM of the microcomputer. Although the instant for spilling of the fuel from the high pressure chamber 40, i.e. the fuel injection end time, is herein spoken of and calculated in terms of a so called spill angle THETA, as in the case of a conventional fuel injection pump including a spill ring, this spilling is as explained here performed electronically. Next, in the step 104, when the crank angle becomes equal to this spill angle THETA, the electromagnetic valve 38 for fuel spilling is turned on, i.e. the injection of diesel fuel to the combustion chamber is by the spilling of the fuel in the high pressure chamber 40 which was being compressed. Then the main fuel injection amount calculation program returns.
In FIG. 4, there is shown the flow chart of an spike interrupt subroutine for the microcomputer incorporated in the control circuit 62, which is performed every time an interrupt occurs on the occasion of the output signal of the transistor 82H at its collector, which is as mentioned before fed back to the I/O port 82E, becoming higher than a certain fixed threshold value. In this spike interrupt subroutine, simply, in the step 106, the value of a count C is set to zero; and then the subroutine returns. The meaning of this is as follows, with reference to FIG. 7. When the electrical signal being supplied from the I/O port 82E to the solenoid coil 105 of the electromagnetic valve 38 for fuel spilling changes from an ON signal to an OFF signal as shown in FIG. 7b, then, due to the inductance of the solenoid coil 105, etc., a transient voltage spike is generated in the voltage thereacross, as shown in FIG. 7a, and the fixed threshold value T which this voltage across the solenoid coil 105 must exceed before an interrupt is caused is set to be so appropriately high that only when the solenoid coil 105 is in its proper continuous state and is functioning correctly as a solenoid coil can the transient voltage thus induced thereacross ever exceed the threshold value T. In other words, the rising of the voltage across the solenfoid coil 105 for a brief period to higher than the threshold value T can be taken as an assurance of the integrity and proper functioning of the solenoid coil 105; and when this voltage spike occurs, as described above, an interrupt occurs and the routine of FIG. 4 is performed, setting the value of the count C to zero.
In FIG. 5, there is shown the flow chart of a discontinuity detection interrupt subroutine for the microcomputer incorporated in the control circuit 62, which is performed every time an interrupt occurs on the occasion of the fuel injection signal being given. In this discontinuity detection interrupt subroutine, first, in the step 108, the value of the count C is incremented by one. And next, in the step 110, a decision is made as to whether the value of the count variable C is greater than or equal to, exemplarily, four, or not; if it is not, which indicates that abnormal operation of the solenoid 105 of the electromagnetic valve 38 for fuel spilling has not yet been decided upon, then the flow of control passes to return directly; but if it is, which indicates that definitely abnormal operation of the solenoid 105 of the electromagnetic valve 38 for fuel spilling is now taking place, because four fuel injection episodes have now occurred since last a voltage spike was detected in the voltage across the solenoid coil 105 of said electromagnetic valve 38 for fuel spilling (vide the resetting to zero of the variable C in the subroutine of FIG. 4), then a flag F is set to 1, so as to indicate that proper action should be taken by the interrupt subroutine of FIG. 6; and then this discontinuity detection interrupt subroutine returns.
In FIG. 6, there is shown the flow chart of a fail safe subroutine for the microcomputer incorporated in the control circuit 62. In this fail safe subroutine, first in the step 114 a decision is made as to whether an ON signal is being currently outputted to the electromagnetic valve 38 for fuel spilling, i.e. whether or not the solenoid coil 105 of said valve 38 is currently being energized; if said solenoid coil 105 is currently energized, then the fail safe routine directly returns. If, on the other hand, it is not, then in the step 116 a decision is made as to whether the value of the flag F is currently 1 or not; if the value of this flag F is not currently 1, indicating that the interrupt routine of FIG. 5 has not set this flag F and that currently the integrity of the solenoid coil 105 of the valve 38 is not in question, then the fail safe routine returns without doing anything. combustion was not taking place up to this present interrupt time and that On the other hand, if the flag F has become set to 1, then the flow of control is passed to the step 118, in which an OFF signal is transmitted to the solenoid of the electromagnetic valve 34 for fuel shutting off, and thereby the diesel engine is definitely and effectively stopped from operating; and the fail safe subroutine returns.
Thus if for four combustion episodes in a row, in this first preferred embodiment, the interrupt routine of FIG. 4 is not obeyed, i.e. no spike of voltage appears across the solenoid coil 105 of the electromagnetic valve 38 for fuel spilling, then the value of the count C will reach four, and then in the step 116 of the fail safe subroutine, a described above, the flow of control will be switched to the step 118 and the electromagnetic valve 34 for fuel shutting off will be actuated to definitely cut off the flow of fuel to the diesel engine and thereby definitely stop said engine. Thus, this action of this fail safe subroutine serves to definitely prevent the diesel engine from continuing to be operated in conditions of doubtful integrity of the solenoid coil 105.
According to the structure described above, it is seen that the fuel injection to the engine is completely and definitely terminated, when it is determined that the electrical characteristics of the solenoid coil 105 of the electromagnetic valve 38 for fuel spilling are abnormal, which may indicate faulty connectivity of said solenoid coil, i.e. may indicate that the valve 38 is always in the closed state and that thus a maximum amount of diesel fuel is being injected to the diesel engine irrespective of the setting of the accelerator pedal thereof. Thus, the danger of too much fuel being injected into the diesel engine, and of consequent overrunning or overrevving thereof, are positively avoided. Thus, this diesel fuel injection pump is made to be fail safe. However, it is noted that the diesel engine is made to be completely unusable and not runnable at all, when such discontinuity in the solenoid coil 105 is detected, in this first preferred embodiment.
The provision of the step 110 for checking that four fuel injection episodes in a row have occurred without any voltage spike on the solenoid coil 105, before deeming that the valve 38 has malfunctioned and is discontinuous, is not absolutely essential, but is for performing a double checking; and accordingly this step 110 may be optionally dispensed with, when appropriate, without departing from the principle of the present invention.
Further, as a useful feature of the shown construction, the set/reset state of the disconnection flag F can be stored in the backup random access memory 82D, along with other relevant variables, and an alarm can be sounded when the disconnection flag F is set; this makes the testing of the system more easy, and the discontinuity of the solenoid coil 105 can be easily confirmed by a mechanic.
In FIGS. 8 and 9, a second preferred embodiment of the fuel injection pump according to the present invention is shown, in which the fail safe function operates in a somewhat different way to that of the first preferred embodiment described above. In these figures, parts which correspond to parts of the first preferred embodiment shown in FIGS. 1 and 2 respectively, and which have the same functions, are designated by the same reference numerals.
In this second preferred embodiment, the structural difference is that the intake passage of this diesel engine has a throttling construction 288, incorporating a main branch in which a main throttle valve 284 is provided, and a bypass branch in which a secondary throttle valve 286 is provided. The accelerator pedal of the vehicle is connected to said main throttle valve 284 so as to regulate the amount of intake air that can flow through said main intake branch; but, as will be seen later, the intake system is so set up and configured that this air flowing through the main intake branch is insufficient for proper engine running, without the air flowing through the bypass intake branch. The secondary throttle valve 286 is controlled by a vacuum actuator 290, which has two vacuum chambers, not particularly shown. One of these vacuum chambers is selectively supplied with vacuum from a vacuum source 292, via a first vacuum switching valve VSV1, which is an electromagnetic vacuum switching valve, and is electrically controlled by a control circuit 62 which will be described later; and the other of the vacuum chambers of the vacuum actuator 290 is selectively supplied with vacuum from said vacuum source 292, via a second vacuum switching valve VSV2, which also is an electromagnetic vacuum switching valve, and is also electrically controlled by the control circuit 62. The function of this system is that: when both of the vacuum switching valves VSV1 and VSV2 are supplied with actuating electrical energy by the control circuit 62, then vacuum is supplied to both the vacuum chambers of the vacuum actuator 292, and the secondary throttle valve 86 is completely closed; when the vacuum switching valve VSV1 is not supplied with actuating electrical energy by the control circuit 62, but the vacuum switching valve VSV2 is supplied with actuating electrical energy by the control circuit 62, then vacuum is supplied to only one of the vacuum chambers of the vacuum actuator 292, and the secondary throttle valve 86 is partly opened; and when neither of the vacuum switching valves VSV1 and VSV2 is supplied with actuating electrical energy by the control circuit 62, then no vacuum is supplied to either of the vacuum chambers of the vacuum actuator 292, and the secondary throttle valve 86 is completely opened.
Corresponding to this structure, the microcomputer in the control circuit 62 in this second preferred embodiment, as shown in FIG. 9, controls the vacuum switching valves VSV1 and VSV2 via the I/O port 82E, as well as performing the other control functions detailed with reference to the first preferred embodiment, which will not be repeated here. And the only difference in the programs performed by this microcomputer, as compared with the programs explained above with respect to the first preferred embodiment, is that: during normal operation a control signal is outputted by the control circuit 62 which causes neither of the vacuum switching valves VSV1 and VSV2 to be supplied with actuating electrical energy, so that no vacuum is supplied to either of the vacuum chambers of the vacuum actuator 292, and the secondary throttle valve 86 is completely opened; and that, in the step 118 of the fail safe routine of FIG. 6, when it has been decided that for four combustion episodes in a row the interrupt routine of FIG. 4 has not been not obeyed, i.e. no spike of voltage has appeared across the solenoid coil 105 of the electromagnetic valve 38 for fuel spilling, rather than as in the case of the first preferred embodiment completely shutting off all fuel supply to the diesel engine by transmitting an OFF signal to the solenoid of the electromagnetic valve 34 for fuel shutting off, and thereby definitely and effectively stopping the diesel engine from operating, in this second preferred embodiment a control signal is outputted by the control circuit 62 which deenergizes the vacuum switching valve VSV1 and energizes the vacuum switching valve VSV2, so as to partly close the secondary throttle valve 286 so as to greatly reduce the flow of intake air to the diesel engine. This means that, in this second preferred embodiment, if for four combustion episodes in a row the interrupt routine of FIG. 4 is not obeyed, i.e. no spike of voltage appears across the solenoid coil 105 of the electromagnetic valve 38 for fuel spilling, then the value of the count C will reach four, and then in the step 116 of the fail safe subroutine, as described above, the flow of control will be switched to the step 118 and the intake passage of the engine will be definitely considerably throttled down. In FIG. 10, a chart is shown to illustrate the effects of such throttling, with reference to a particular exemplary diesel engine. The line A indicates the engine rotational speed attained with respect to fuel injection amount in one pump stroke, when the throttling amount of the intake passage of the engine corresponds to a diameter of about 22 mm; and it is seen from this that the engine rotational speed is able to rise to realistic levels, when the fuel injection amount is increased, corresponding to maximum engine rotational speed operation at full load, since in these circumstances intake passage throttling is not in fact the limiting factor on engine rotational speed. On the other hand, the line B indicates the engine rotational speed attained with respect to fuel injection amount in one pump stroke, when the throttling amount of the intake passage of the engine corresponds to a diameter of about 12 mm; and the line C indicates the engine rotational speed attained with respect to fuel injection amount in one pump stroke, when the throttling amount of the intake passage of the engine corresponds to a diameter of about 8mm. From these lines, it will be understood that in these conditions intake passage throttling is in fact the limiting factor governing engine rotational speed, and that the engine rotational speed is prevented from rising above certain predetermined values (depending upon the effective diameter of the intake passage), no matter how much fuel is injected in each pump stroke. Thus, this action of this fail safe subroutine serves to definitely prevent the diesel engine from rotating very fast, while however still allowing emergency operation of the diesel engine at a relatively low efficiency and power output which present no substantial risk of any difficulty in operation, or of running away.
According to the structure described above, it is seen that the normal operation of the engine is completely and definitely terminated, when it is determined that the electrical characteristics of the solenoid coil 105 of the electromagnetic valve 38 for fuel spilling are abnormal, which may indicate faulty connectivity of said solenoid coil, i.e. may indicate that the valve 38 is always in the closed state and that thus a maximum amount of diesel fuel is being injected to the diesel engine irrespective of the setting of the accelerator pedal thereof. Thus, the danger of too much fuel being injected into the diesel engine, and of consequent overrunning or overrevving thereof, are positively avoided. Thus, this diesel fuel injection pump is made to be fail safe. And, in this second preferred embodiment, it is noted that the diesel engine is not made to be completely unusable and not runnable at all, when such discontinuity in the solenoid coil 105 is detected, but can in fact be operated in a reduced power mode, for instance so as to be able to limp to a service facility.
Although the present invention has been shown and described with reference to the preferred embodiments thereof, and in terms of the illustrative drawings, it should not be considered as limited thereby. Various possible modifications, omissions, and alterations could be conceived of by one skilled in the art to the form and the content of any particular embodiment, without departing from the scope of the present invention. For example, although in the shown preferred embodiment the stopping of the diesel engine is not performed until four successive combustion episodes have proceeded for longer than they ought, this counting is only performed in order to make quite sure that abnormal combustion is occurring in the combustion chamber, and such counting could be dispensed with and the engine could be stopped after only one such occurrence of overlong combustion. Various other modifications are also possible. Further, it should be noted that the present invention is applicable to a conventional sort of mechanical diesel fuel injection pump in which the termination of each fuel injection spirt is performed by a spill ring, rather than by an electromagnetic valve as in the shown preferred embodiment. Therefore it is desired that the scope of the present invention, and of the protection sought to be granted by Letters Patent, should be defined not by any of the perhaps purely fortuitous details of the shown preferred embodiments, or of the drawings, but solely by the scope of the appended claims, which follow. | A fuel injection pump for a diesel engine includes an input shaft rotated with the crankshaft, and a housing and a plunger which slides in a bore formed in the housing and is coaxial with the input shaft, with a high pressure chamber being defined at an end of the plunger between it and the bore. The plunger rotates with the input shaft and reciprocates so as to pump fuel at high pressure from the high pressure chamber to the engine cylinders, under the control of an electrically actuated electromagnetic valve, comprising a solenoid coil, which selectively vents the high pressure chamber according to the control of a control means, so as to provide fuel injection in appropriate amount to the diesel engine. There is provided a means for determining whether or not the voltage across the solenoid coil of the electromagnetic valve, when supply of power thereto changes from the ON to the OFF condition, rises higher than a certain value, or not. If a determining means detects that this voltage across the solenoid coil has not so risen, this lack of high transient voltage spike indicating that the solenoid coil may be discontinuous or functioning abnormally, then the engine is restrained. This restraint may consist of interrupting fuel flow to the engine to totally stop it, or of restricting air intake to the engine so as to put a ceiling on its rotational speed. | 5 |
The applicant hereby submits this preliminary amendment for a Continuation-in-Part application Ser. No. 08/918,333 filed Aug. 26, 1997. The parent U.S. Pat. No. 5,662,665 is incorporated in its entirety in this continuation-in-part.
SUMMARY
The application hereby encloses the new Continuation-in-part specifications, claims, and drawings for the suture needle holding instrument. In the parent patent the biasing member maintained pressure on the side of the needle by the sliding member. In the new design, the biasing member moves the sliding member to a maximum open position when the needle holding instrument is opened.
Once a suture needle is placed in the transverse channel, the sliding member moves forward against the side of the needle by means of a newly added cam and camming surface that are activated as the needle holder jaws are closed. The camming surface is spring loaded to allow for complete closure of both the sliding member against the side of the needle and the opposing jaw against the face of the needle.
FIELD OF THE INVENTION
The subject invention relates generally to surgical instruments, and more particularly to a holding instrument, for a suture needle.
BACKGROUND OF THE INVENTION
It is common surgical practice for a physician to join various tissues by passing a needle with attached suture through the tissue. The suture is then tied to approximate the tissues. There are several prior art plier-like instruments available for gripping and holding suture needles. A conventional instrument for passing the needle through the tissues is a needle holder which usually has a pair of movable, opposed jaws connected to a pair of handles. The handles in turn have a scissor configuration with a locking ratchet mechanism to maintain gripping pressure on the needle held in the jaws of the needle holder.
Needle holder jaws commonly have a tungsten carbide, serrated surface in a diamond or cross-hatched pattern to enhance the firmness with which the needle is grasped. The ratchet mechanism between the scissor handles is locked as the handles close thereby maintaining firm gripping pressure on the suture needle. Despite this construction, needles are frequently subject to twisting or slipping in the jaws of needle holders as they pass through tissue. Normally the surgeon releases the ratchet mechanism only after the needle has safely passed through the tissue. If during passage of the suture needle, the needle twists or moves off the desired axis of travel, tissue may be torn, needles may be lost, and the operation time prolonged. Twisting movement of a suture needle in the needle holder jaw is a frustrating and dangerous problem which has not been solved by prior art.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a surgical needle holder that securely holds a suture needle as it passes through tissue. It is an object to minimize slipping or twisting of the suture needle in the jaws of the needle holder as the needle passes through tissue. Prior art has not solved the long standing problem of unwanted motion of the suture needle while still in the grasp of the needle holder.
The present invention consists of a surgical needle holder with finger-loop handles which have a ratchet locking mechanism connected to two elongated scissoring members that in turn define specialized opposing jaws that hold the suture needle. In this improved invention the jaws of the needle holder have a distal transverse channel that securely hold the suture needle at a right angle as it passes through tissue. The transverse channel in the needle holder jaw is of adjustable width to accommodate suture needles of different size. The width is easily adjusted during a surgical procedure, so that needles of various width can be accommodated without changing needle holders. In addition, the floor of the transverse channel is of ribbed design to mate with the surface of the suture needle.
Both jaws of the needle holder have a mirror-imaged adjustable transverse channel design, so there is no top or bottom orientation required for the needle holder. The needle holding transverse channel adjusts to the diameter of the needle by a biasing sliding member of the needle holder jaw. This design allows quick placement of the needle in the holder and maintains proper, secure alignment of the needle at right angles to the jaws of the needle holder.
BRIEF DESCRIPTION TO THE DRAWINGS
FIG. 1 is a side view of the subject needle holder showing a suture needle positioned in the specialized transverse channels 28, 30.
FIG. 2 is a cross section of the needle holder jaw showing the longitudinal grooves in which the top sliding member 38 moves.
FIG. 3 is a top view of the needle holder jaw showing the sliding member 38, distal transverse channel 28 and proximal spring compartment 44.
FIG. 4a is an oblique view of the needle holder jaw showing the transverse channel 28 with varing width maintained by sliding member 38.
FIG. 4b is a cross section of the preferred suture needle.
FIG. 5 is a side view of the transverse channel with a small suture needle.
FIG. 6 is a side view of the transverse channel with a large suture needle.
FIG. 7 is a side view of the needle holder jaw showing the removable/disposable feature for the entire jaw mechanism.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the needle holding instrument of the present invention with the embodiment of a specialized distal transverse channel in the jaws of the needle holder to securely grasp a suture needle. The needle holder 14 is preferably constructed of surgical stainless steel.
At the proximal end finger loops 16 and 18 are of a size to accept thumb or finger within the loop. The finger loops are in turn connected to elongated arms 6 and 8.
Protruding at or near the junction of the finger 16, 18 and the elongated arms 6, 8 is a conventional locking ratchet mechanism 22. The ratchet lock 22 consists of two short members, at the junction of the finger loops with the elongated arms, and perpendicular to the arms of the needle holder. These members have matching notches on their opposing surfaces which engage one another, locking, as the finger loops are brought together. Such locking ratchet mechanism is well known to the art.
The elongated arms are of equal length and terminate at a pivot joint 20. Conventionally the pivot joint 20 is constructed such that the elongated arms of the needle holder terminate in a short, flat, widened area. Any pivot method can be used, traditionally, the flat area of one arm passes thru a matched opening in the other arm with both being united to one another by a pin passing through the center of the flat zone. Both arms pivot about this pin establishing the scissors action of the needle holder. This configuration allows the distal jaws to be centered on one another rather than offset as is the case with the usual cutting scissors. The elongated arms for open surface surgery are shorter than those in the case of laparoscopic surgery.
The finger loops and elongated arms allow the surgeon to grasp the instrument and apply pressure to close it. Once closed, the ratchet mechanism locks to maintain the closed position. The ratchet mechanism is opened by the surgeon applying opposing pressure to the finger loops. The pivot joint allows for ease of opening and closing the jaws 10 and 12. The needle holder jaws taper in both width and height to a terminal, rounded point. This pointed tip allows for good directional placement and visualization of needle position by the surgeon using the instrument.
The needle holding jaws with opposed surfaces 24 and 26 contain specialized transverse channels 28 and 30, shown in greater detail in FIGS. 2-4. The width of the transverse channel varies by means of sliding member 38. Construction of the needle holder jaws is of surgical stainless steel. Alternatively the jaws may be made of high impact plastic to afford a disposable nature to this functional section of the surgical instrument. This would allow for cleaning and sterilizing the reusable parts and for discarding the jaws in the case of fatigued surfaces that no longer securely grasp the suture needle.
FIG. 2 is a section across one needle holder jaw. The sliding member 38 is of surgical stainless steel or tungsten carbide construction. All stainless steel or tungsten carbide parts can be sterilized and re-used. Alternatively, it is made of high impact plastic for disposable application. The sliding member 38 is rectangular in shape and comprises a major portion of the needle holder jaw. The surface of the sliding member is preferably finished in a serrated or cross-hatched pattern. This provides an alternative grasping surface for a needle or suture the latter being the case when the needle holder is used to tie the suture!. The sliding member moves back and forth as constrained by longitudinal grooves 40. The longitudinal grooves are provided in the side of the needle holder jaw to a depth to securely hold tabs 46 and 48. Two or more tabs 46 and 48 which are part of the needle holder jaw. The motion of the sliding member back and forth in the longitudinal grooves 40 allows for variation in the width of the transverse channel described in FIGS. 1 and 5-7.
FIG. 3 is a top view of the needle holder jaw. In the pictured embodiment, the sliding member 38 moves in the longitudinal grooves 40 by means of four tabs 46, 48, 50, 52. These tabs are introduced and removed through vertical openings 56, 58, 60, 62, in the side of the needle holder jaw to allow the tabs to enter the longitudinal groove 40. The sliding member 38 can be removed and replaced in position by moving it rearward with maximum pressure pushing it back until tabs 46, 48, 50, 52 meet four matching vertical openings 56, 58, 60, 62, in the upper edge of the longitudinal grooves 40. The motion is to push the sliding member back as far as possible so that the tabs engage the vertical openings and the sliding member can be lifted up and free. The reverse motion allows replacement of the sliding member in the needle holder jaw.
FIG. 4a is an oblique view of a preferred embodiment of the needle holder jaw. When the needle holder is opened, the sliding member 38 moves rearward to establish a 3.0 mm opening at the front of transverse channel 28. The sliding member 38 moves rearward by means of biasing coil spring 42 which is secured to the forward face of foot 64 which extends vertically from the under surface of sliding member 38 into the spring compartment 44. When the needle holder is opened, the force of spring 42 against the front wall of spring compartment 44 pushes on foot 64 to move the sliding member 38 rearward to provide the 3.0 mm opening in transverse channel 28.
When the needle holder jaws are closed, the sliding member moves forward by means of cam 41 on one jaw surface pressing against camming surface 43 on the other jaw. The cam 41 may be a separate projection or the rearward surface of the elongated arms 6,8 in front of pivot joint 20. The camming surface is comprised of a push rod 55 which is connected to coil spring 57. Coil spring 57 is secured to the rearward face of foot 64 which projects vertically from sliding member 38. This configuration allows the sliding member of one jaw to move forward against needles of varying width in the transverse channel while the other jaw closes in direct contact with the concave surface of the seated needle. The difference in the closing of the needle holder jaw for contact of the sliding member against the needle and the distance for the other jaw to contact the needle is taken up by spring 57.
Once the needle holder jaws are closed, the sliding member is firmly held in place against the needle both by the camming member and by the closing force of opposing jaws. In a preferred embodiment, the suture needle is further securely held in position in the transverse channel 28 by virtue of one or more transverse ribs or elevations 66 in the floor of the transverse channel. These ribs mate with corresponding longitudinal grooves in the surface of the suture needle as will be described in more detail with reference to FIGS. 4-7. The surface of the needle holder jaw not involved with the transverse channel are preferably of a serrated or cross hatched design to allow for alternate needle grasping capability. The depth of the transverse channel 28 is approximately 1 mm. In the floor of the transverse channel 28 there are one or more transverse triangular ridges or elevations 66 which are designed to engage longitudinal grooves 68 on the surface of the suture needle 70. The preferred cross-section of the suture needle is depicted in FIG. 4b. This configuration allows the suture needle 70 to seat in the transverse channel 28 and maintain its position at a right angle to the axis of the needle holder jaws. In surgical applications the needle must maintain its location in the needle holder as it passes through tissue. Any motion of the suture needle from the desired right angle results in lost time or a lost needle in addition to the potential damage of tissue by unwanted needle motion.
FIG. 5 shows the side view of the needle holder jaw with a suture needle 70 in position in the transverse channel 28. This needle is fairly small resulting in opening of the sliding member 38 only a minimal amount. FIG. 6 depicts a larger needle in the transverse channel 28 resulting in an increased opening of the sliding member 38. Note that in both FIGS. 5 and 6 there is mating of the transverse ridges 66 in channel 28 with the grooves 68 in the needle 70 surface. This provides a secure grasp of the needle 70. The firm positioning of the suture needle 70 is further enhanced by the closed approximation of the opposed needle holder jaws 10, 12 that aid in maintaining the sliding member 38 against the seated needle 70. There are three separate constraints being applied simultaneously to the suture needle to maintain its position in the transverse channel 28. First, the transverse ridges 66 in the channel are mating with the grooves 68 in the surface of the suture needle 70 to inhibit lateral movement. Second, the forward pressure of biasing by the sliding member 38 on the needle maintains the needle in the transverse channel 28. The third force is the pressure of the closed jaws 10, 12 of the needle holder 14 on each other which is maintained by the locked ratchet mechanism 22. This last force is additive to the first two by maintaining the sliding member 38 firmly against the needle 70 and by keeping the needle 70 seated on the transverse ridges 66 in the transverse channel 28. Generally the needle 70 will seat in the lower jaw as the convex surface of the needle is pushed into place in the needle holder jaw. Both jaws 10, 12 are the same, so the upper transverse channel 30 facing the concave surface of the needle will also be utilized if the needle is thick enough to activite the sliding member 38. With a suture needle 70 properly seated the opposing surfaces 24 and 26 of the needle holder jaws will be in contact.
Alternatively, depending on the size of the needle holder 14 and the suture needle 70 being used, only one jaw of the needle holder 14 might have the specialized transverse channel 28 herein described. The opposing needle holder jaw surface 24, 26 would be of flat, conventional design without a transverse channel 28. This may require a top/bottom designation to the needle holder jaws 10, 12 for ease of use. This can be done by marking the needle holder handles or color coding the transverse channel 28 for quick orientation. In addition, it is possible that in small needle holder applications that there would not be a sliding member 38 in the design. This would require the width of the transverse channel 28 in the needle holder jaw to be of a fixed dimension. Thusly, in this situation suture needles 70 of only one size would fit into the transverse channel 28. This configuration may be desirable in needle holders for fine vascular or ophthalmologic surgery.
Construction of the improved needle holding instrument is of surgical stainless steel or tungsten carbide. Alternately, the specialized jaws may be constructed of high impact plastic and designed to be disposible and replaceable as a unit on the needle holder. FIG. 7 shows a side view of a disposable configuration in which the entire jaw mechanism can be removed from the needle holder. There is a central longitudinal support 72 extending forward from the needle holder pivot joint 20. The jaw mechanism with specialized transverse channel 28 fits over the longitudinal support 72 and snaps in place. This is done by means of a tongue and groove joint 74 at the distal portion and a snap-lock 76 at the proximal end of the needle holder jaw. The tongue and groove joint 74 has an angled projection of metal from the support 68 which fits into an angled groove in the inner surface of the disposable jaw insert. The snap-lock mechanism 76 consists of a transverse spring on the jaw, the ends of which fit into corresponding grooves in the longitudinal support 72 as the jaw is pressed into position. The motion to place the jaw insert is to engage the distal tongue and groove joint 74 first then press the rear of the jaw down to allow the spring ends to snap into place in the grooves in the longitudinal support 72. To remove the disposable needle holder jaw insert, the proximal snap-lock joint 76 must be disengaged on one side with an instrument then the insert can be lifted up and off the longitudinal support.
The above described embodiment of the invention is the preferred form. However, it is understood that changes in the design construction may be made without departing from that which is herein claimed. For example, the transverse channel 28 may be placed at an angle other than a right angle to the axis of the needle holder for certain surgical applications. The needle 70 may be more or less curved, or may be straight. The needle grooves 68 and ridges 66 may be triangular, squared, rounded or eccentric. The spring 42 may be a leaf or coiled spring. The sliding member 38 may provide no tabs, 2 tabs, 4 tabs, or the like. Substitute materials may be used. | A surgical instrument for holding a suture needle is provided. The instrument is of a scissors configuration with elongated arms having finger loops at one end and jaws at the other end to grasp a suture needle. This improved instrument has specialized jaws containing a transverse channel that securely holds a suture needle at a right angle to the axis of the needle holder jaws. The width of the transverse channel adjusts to the size of the suture needle by means of a cam and spring loaded camming surface which move a sliding member against the side of a suture needle as the jaws of the needle holder are closed. This improved configuration significantly reduces the long standing problem of suture needle twisting or rotation in the needle holder jaws as the surgeon passes the needle through tissue. | 0 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 15/015,180, now U.S. Pat. No. 9,523,204 which is a divisional of U.S. application Ser. No. 14/626,975, now U.S. Pat. No. 9,267,292, which is a divisional of U.S. application Ser. No. 14/210,699, now U.S. Pat. No. 9,021,748, which claims the benefit of U.S. Provisional Application No. 61/782,625 filed Mar. 14, 2013.
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT
(Not Applicable)
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
(Not Applicable)
REFERENCE TO AN APPENDIX
(Not Applicable)
BACKGROUND OF THE INVENTION
The invention relates broadly to structures used to keep debris from gutters, and more particularly to a structure for preventing leaves from entering into gutters.
Rain gutters (also known as eavestroughs or, gutters) are narrow channels or troughs that collect and divert water flowing off of a roof. Gutters have been disposed at roof edges for centuries to catch precipitation and either redirect it to a storage vessel, such as an underground cistern, or away from the foundation of the building to prevent the precipitation from damaging the building to which the gutters are attached. Conventional gutters mount to a face of the building, such as a soffit fascia, with the lip of the rear edge of the gutter just under the drip edge of the building's roof. When water runs down the roof, it falls under the force of gravity into the gutter, collects in pools and flows by gravity out of the inclined gutter into a vertical downspout. The downspout carries the water to a storage vessel or away from the foundation of the building.
Solid particles that fall onto roofs also fall into uncovered gutters. For example, sticks, leaves, seeds, needles and other particles fall onto roofs, typically from overhanging trees, and then roll or slide into gutters. Smaller particles in small quantities can be carried by rain water out of gutters and are harmless, other than when they deteriorate in cisterns and cause spoilage. However, sticks and larger particles, or small particles in larger quantities, cannot be carried away by the water flowing in a gutter. Such sticks and particles collect together to form a barricade, and then smaller particles are filtered by the debris to block the satisfactory flow of water from the gutter into the downspout. The water then collects in the gutter and creates a sanitary hazard and/or overflows, thereby damaging the building and gutter and defeating the purpose of the gutter system.
There are numerous systems for preventing, or reducing, the infiltration of particles into the open tops of gutters. These are placed over gutters to keep water flowing instead of being clogged by leaves and debris. These systems include porous, filtering materials, such as expanded metal and polymer screens, along with solid “caps” that drive solid particles over the cap while depending on the surface tension of water to flow over the cap and gutter and around a solid panel into the gutter. Brush-like structures have also been placed in gutters, and coiled, spring-shaped wire structures have been placed in gutters to extend along the length of the gutter. One problem with the coil apparatus is that leaves and other debris that are low-hanging through the wires cannot clear the far edge of the gutter as they move downhill and they catch the far edge of the gutter. The surface tension method using a sheet-type cap over the gutter appears to be the best at self-clearing, but it can cause a mold slime-like formation in the darkened gutter.
The prior art of which the inventor is aware provides advantages over an open-top gutter, but also disadvantages. To applicant's knowledge, all prior art fails to provide sufficient certainty that debris will neither clog the gutter nor the filtering apparatus. Therefore, the need exists for a method and means for keeping gutters clear of leaves and other debris while allowing sunlight and airflow into the gutter, which reduces mold and slime buildup on the filter and gutter.
BRIEF SUMMARY OF THE INVENTION
The invention contemplates a means to bridge over a gutter to allow leaves and other debris to slide off the roof, across the bridging structure above the gutter, and onto the ground without dropping into or catching onto, the gutter or filter. This is accomplished with a novel bridging structure that is described herein and shown in the illustrations. The structure has a plurality of rods aligned parallel to and along the downward sliding direction of the leaves and other debris. These rods are positioned substantially parallel and as close to one another as possible to prevent significant debris from falling into the gutter between the rods while still allowing the water to pass through into the gutter through the openings between the rods.
Except for very small particulate, the apparatus prevents most or all debris that comes into contact with a roof from entering the gutter, while still allowing rain and other liquid and small particulate to be carried away in a desirable manner by the gutter and downspouts. The apparatus also allows wind to blow up through the gutter filter to dislodge leaves and other debris, as well as dry out the gutter by the sun penetrating through the aligned rods of the apparatus.
The apparatus is referred to herein as a gutter leaf slide bridge (GLSB). The GLSB is designed so that the water and small quantities of very small particles that constitute non-clogging debris fall into the gutter, and larger debris, such as leaves, sticks and large seeds, roll or slide across the GLSB beyond the outside edge of the gutter and fall to the ground. The GLSB allows sunlight and air movement through the gutters beneath it, thereby preventing a slimy mold buildup in the gutter found with many systems that enclose the gutter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a side schematic view illustrating an embodiment of the present invention.
FIG. 2 is a side schematic view illustrating an alternative embodiment of the present invention.
FIG. 3 is a top schematic view illustrating a mechanism for forming a portion of the present invention.
FIG. 4 is a side schematic view illustrating an alternative embodiment of the present invention.
FIG. 5 is a side schematic view illustrating an alternative embodiment of the present invention.
FIG. 6 is a side schematic view illustrating an alternative embodiment of the present invention.
FIG. 7 is a side view in section illustrating a fastener portion for the present invention.
FIG. 8 is a side schematic view illustrating an alternative embodiment of the present invention.
FIG. 9 is a schematic view in perspective illustrating an alternative embodiment of a portion of the present invention.
FIG. 10 is a side schematic view illustrating an alternative embodiment of the present invention.
FIG. 11 is a front schematic view illustrating the embodiment of FIG. 1 .
FIG. 12 is a front schematic view illustrating an alternative embodiment of the present invention.
FIG. 13 is a magnified schematic view illustrating the embodiment of FIG. 12 .
In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific term so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For example, the word connected or terms similar thereto are often used. They are not limited to direct connection, but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art.
DETAILED DESCRIPTION OF THE INVENTION
U.S. Provisional Application No. 61/782,625 filed Mar. 14, 2013 and U.S. Non-provisional application Ser. No. 14/210,699 filed Mar. 14, 2014 are hereby incorporated in this application by reference.
In an embodiment shown in FIGS. 1 and 11 , the GLSB 10 uses substantially parallel, spaced rod members 12 to form the bridge that supports the debris as it is carried across the upwardly facing opening of the gutter 14 to the far edge 14 f of the gutter 14 . The rod members 12 can be made of any metal, such as steel or aluminum, or plastic, polymer-reinforced composites or any other suitable material. The rod members 12 preferably range in diameter from about 0.03 to about 0.06 inches. The rods should be of minimum diameter possible and the sizes listed can be combined with larger rods or smaller rods. Of course, other diameters are contemplated if they are sufficiently strong and otherwise suitable. The rods are a length that allows them to span the distance across the gutter 14 that is required to carry and support debris over the gutter 14 . As an example, for a conventional piece of five inch wide aluminum gutter, the rod member 12 is a length that permits it to overhang the far edge 14 f by about one-half to one and one-half inches. Therefore, useful rods could be six to seven inches long, depending on how and where the rods are attached to the building or gutter.
The rods are preferably spaced laterally from each next adjacent rod to form a gap therebetween of about one-quarter of an inch or less, but this distance can be modified as will become apparent to the person of ordinary skill. Each rod member 12 is preferably aligned substantially perpendicular to the gutter's longitudinal axis, although a small angle is possible as will become apparent from the description herein. When aligned substantially perpendicular to the gutter's longitudinal axis, the rod members 12 are aligned with their longitudinal axis substantially along the direction debris and water flow down the roof 20 when under the influence of gravity. That is, the rod members 12 are substantially parallel, or only slightly transverse, to the direction water and debris flow down the roof 20 under the influence of gravity (wind and other effects may vary the direction). The rods are also substantially parallel to one another. This configuration allows the rod members 12 to provide as little resistance to continued flow of debris over the gutter, while allowing water to flow between the rod members 12 into the gutter with little resistance. In order to maintain the rods parallel to one another, the rods themselves preferably have a spring effect that is substantial enough that if a rod is bent to one side, upon release it returns substantially to its original position. This “spring effect” can arise by using spring steel, for example.
Each rod member 12 can be mounted at the gutter 14 near the inner edge of the gutter 14 i . The rod members 12 extend from or near the roof's edge 20 e in cantilevered fashion above and beyond the far edge 14 f of the gutter 14 , as shown in FIGS. 1 and 11 . A vertical gap, g, is formed between the top surface of the far edge 14 f of the gutter and the lower surfaces of each of the rod members 12 . The vertical gap, g, is to allow leaves and leaf-like debris that have portions (stems, thorns, etc.) that may extend downwardly through the gaps between the rods to flow to the ends of the rods without resistance, such as from catching on the gutter's far edge, as the debris slides down the parallel rod members 12 . The vertical gap between the far ends of the rods and the top of the gutter allows leaves and other debris that are low-hanging between and beneath the rods to slide past the end of the gutter as they move downhill along the rods, and not catch thereon.
The rod members 12 are substantially parallel and form a “comb-like” structure over the gutter 14 with the “teeth” of the “comb” being formed by the rod members 12 . A spine or frame 12 f , to which the rods mount, is substantially perpendicular to the rods and attaches uphill of the gutter 14 . The rod members 12 are cantilevered to as far beyond the far edge 14 f of the gutter 14 as is necessary to assure most or all debris completely bypasses the gutter 14 and falls away from the gutter. The back or “spine” of the “comb” preferably attaches to the house structure 30 , roof edge 20 e , or inner edge 14 i of the gutter 14 , but the frame 12 f can simply rest upon the surface of the roof 20 . The rods 12 are preferably angled substantially parallel, or slightly transverse, to the roof 20 , so that a generally downhill slope results. The frame can be integrated into the lower edge 20 e of the roof 20 , such as by inserting rods into spaced apertures disposed along a half-round piece of plastic, wood or metal that is attached at the lower edge of the roof, within the thickness of the lower edge 20 e.
In one embodiment contemplated, the frame of the “comb” is integral to the gutter's inner edge 14 i , having been mounted there during manufacture of the gutter. In another embodiment contemplated, rubber or other flexible roofing sheet material that is self-adhesive is adhered to the roof and over the frame of the comb-shaped structure to direct water falling down the roof over the frame of the comb. The rods can extend through apertures formed in the rubber sheet so that the sheet extends beneath the rods a short distance after passing over the frame and toward the roof edge 20 e . The rods cantilever above the gutter's far edge.
The rods' lengths can be a few inches to about a foot or even more depending on whether the rear attachment point of the rods is at the back of the gutter or on the roof. Thus, the rods preferably extend from just above and just beyond the far edge 14 f of the gutter to as far back toward or on the roof 20 as is necessary to reach the desired mounting or resting point of the frame. The rods 12 are sloped downward from the rear attachment point at the frame to the far edge 14 f of the gutter 14 to form a self-clearing leaf slide that guides leaves and leaf-like debris along a continuously sloped structure away from the sloped roof, onto the sloped rods and then off of the rods to the ground or a container for collection.
One type of GLSB uses short lengths of rods attached to a frame formed from a pipe 150 or round drill stock, as shown in FIG. 2 . The pipe 150 is attached above the rear edge 114 i of the gutter 114 with u-bolts (not visible) or a novel snap-in fastening device that allows the pipe 150 to pivot within the u-bolts or other fastener in the manner of a hinge. This pivoting is along an angle of about 30 to 90 degrees to an “up position” (see dashed lines in FIG. 2 ) from the rods' 112 operable location above the front gutter edge 114 f . The pivoting allows access to the inside of the gutter 114 for periodic cleaning or other maintenance. As noted above, the pipe 150 can be mounted to a structure that is deliberately formed in the gutter during manufacture of the gutter (see FIG. 6 ), or the pipe 150 can be retro-fitted, or the pipe can be mounted to the house's roof 120 or fascia.
One advantage of the pipe 150 structure shown in FIG. 2 is that the water tends to be driven downwardly, perpendicular to the rods 112 . As the water flows off the roof 120 it immediately flows along the curved surface of the pipe 150 , which is substantially perpendicular to the rods 112 at the intersection of the rods 112 with the pipe 150 . By directing the flow of water perpendicular to the rods at the intersection, this configuration reduces the probability that the water will cling by surface tension to the rods 112 and flow off the ends of the rods rather than fall into the gutter 114 . Thus, when the pipe 150 forms an approximately ninety-degree angle with the rods 112 at their intersection, there is a substantial structural and functional advantage.
Another GLSB is made from a wire mat 200 , as shown in FIG. 3 . The mat 200 can be about one foot wide, and is made by bending one strand of wire 202 back and forth around a die that consists of a plurality of dowels 204 or other prepared, solid structures at each side to form parallel wires that serve as the rods spaced about one quarter inch apart (see FIG. 3 ). Once the wire 202 is wound through and around the dowels 204 , the dowels are moved apart by force to remove any slack in the wire 202 and form the final length of the rods. The curved portions at the ends of each pair of rods can be cut off, or they can be retained and bent downwardly and inwardly to allow the debris to clear the curved ends as it falls off the rods, and also direct water into the gutter using surface tension on the rods. In this case the downwardly bent portions may not touch the gutter, but form a barrier to prevent larger rodents and other creatures from entering the gutter. The curved portions can be bent downwardly and inwardly to form a support leg that rests upon the far edge of the gutter as described herein, which also provides a barrier for pests.
As shown in FIG. 4 , one side of the mat 200 so formed is attached to the roof 220 (such as by a screw 210 extending through the roof side curved portions) and the other side of the mat 200 cantilevers above the far edge 214 f of the gutter 214 . The vertical gap, g 2 , formed between the front gutter edge 214 f and the underside of the mat 200 can be maintained by forming support structures at periodic intervals along the mat's length using parts of the mat formed. For example, during manufacture of the wire mat 200 , some of the wire 202 can be bent toward the gutter to form spaced “legs” 240 under the mat 200 that rest on the far edge 214 f of the gutter (see FIG. 5 ). These legs are spaced supports that contact the gutter 214 and space the gutter 214 from the mat 200 . A continuous GLSB can be made using this configuration because the top surfaces of the rods extend past the far edge of the gutter.
The mat 200 can be bent in its long direction along the roof to fit into a valley formed between two intersecting and transverse roof sections. A rubber roofing material can be adhered over the uppermost portion of the mat and the roof in order to force water and debris onto the top of the mat. Such a configuration permits the mat to carry debris out of the valley where it would otherwise collect, but water is permitted to flow through the rods to the gutter. Preferably, the lower ends of the rods extend over the far edge of the intersecting gutters' corner (or any vertical shield that is mounted to the gutter lip at this corner to direct the large volume of water from the valley into the gutter) in order to bridge entirely over the gutter.
By using wire stock from a large spool of wire at the job site, a mat can be formed on-site of desired width, wire spacing and length using special wire-forming equipment made for this purpose. As the wire (about one-sixteenth inch diameter) comes off the reel it is work-hardened and made straight. Next it is placed in a flat die having dowels at each end of the mat's width to wrap around and form the wire spacing of the rods. The dowels at each end are pulled apart for forming the final length of the mat (see FIG. 3 ). The flat mat formed is cut into lengths, for example three feet long. Then the mat can be bent to curve the mat for each field need of gutter width and height to roof relationship. A gap can be formed between the far edge of the gutter and the wire mat bridge. Also a cantilever (ideal) mat can be formed by attaching a bent mat to the roof and cutting off the opposite end to form separate rods 212 as shown in the illustration of FIG. 4 .
In one embodiment, the invention is formed in units of a specific length, such as three feet, and each unit is attached to other units in series. The attached collection of units is mounted along the gutter's length. The length of each unit of the apparatus (as measured along the gutter's length) can be on the order of a few feet for ease of installation of each unit. Alternatively, the apparatus can be constructed to be continuous along the length of the gutter in some embodiments so that there are no connectors or weaknesses that might be present in a series of connected units that depend on the installer's skill in connecting them.
The invention can take the form of a “comb” with the “teeth” being the rods, rails or bridging components and the transverse spine being a frame to which the rods mount. Alternatively, the invention can be in the form of disks with spacers like a large diameter washer spaced with a smaller diameter washer. Alternatively, a broom-like device can be used with the broom straws acting as the bridge over the gutter, and the straws cantilevering above the ends of gutter the same as the comb teeth forming a gap.
As the parallel rods are made closer and closer together, this decreasing gap improves the action of sieving debris. However, the closer the rods are together the more likely capillary action will occur, which could cause some of the water to cling to, and flow along, the rods past the far edge of the gutter, thereby defeating the purpose of the gutter. The surface tension of the water and its velocity direction as it comes off the roof or rod-holding device can be in the direction of the rods. This problem can be reduced or eliminated by using finer and flatter rods. Another solution is to form sawtooth-shaped (when viewed from the side) and/or v-shaped (when viewed from the end) profiles on the bottoms of the rods that cause the water to have a smaller surface to cling to so it drops off into the gutter before reaching the ends of the rods.
An alternative solution can be obtained by placing the rods at an angle to the water direction coming off the roof, and another uses the surface tension of the water clinging to a sheet that the rods pass though to drop the water below the rods. For example, if a rubber sheet is adhered at its top edge to the roof and extends a short distance down the roof to cover the frame of the rods, the rods of the invention can pierce the sheet, which causes the rods to extend transversely (at an angle to the sheet) beyond the sheet's point of attachment to the roof. The sheet thus extends from above the rods to below the rods with the rods extending through the sheet. This configuration creates a flow path for water to flow onto the sheet from the roof, down the sheet and through the rods by clinging to the sheet due to surface tension. In this configuration, the water follows the sheet down through the rods, rather than following the rods at an angle to the sheet.
Shorter rods could be passed under and between the main rods 12 , 112 and 212 that carry off the leaves, and the shorter rods (which do not have to be as long as the main rods) cause the water on the bottoms of the main rods to be more likely to fall into the gutter, rather than be carried over the ends of the main rods and past the gutter. Such shorter rods could also help support the upper rods that cantilever over the far, outer edge of the gutter. Additionally, smaller diameter (e.g., one-thirty second of an inch) or shorter (or both) rods can be alternated with the preferred main rods (e.g., one sixteenth of an inch diameter) described herein to help carry smaller debris and thereby reduce the amount of matter that can hang down between the rods as the matter passes over the far lip of the gutter. This is illustrated in FIGS. 12 and 13 , in which the main rods 612 a are twice the diameter and long enough to reach past the far edge of the gutter, and the smaller diameter rods 612 b are substantially the same length, but half the diameter. The smaller diameter rods 612 b can be shorter, and preferably do not carry substantial weight of larger debris that falls onto the main rods 612 a . Instead, the row of smaller diameter rods 612 b filter the smaller debris that falls past the larger main rods 612 a , and, because they are smaller diameter, the rods 612 b promote water falling into the gutter 614 , rather than flowing past the gutter's far edge. Furthermore, the smaller diameter rods 612 b may be shorter than the gutter's width, so that even if water flows to their ends and then drops, the water falls into the gutter 614 . If a second row of smaller diameter rods is placed beneath the row of larger diameter rods, the gaps between the smaller rods can be smaller than the gaps between the larger rods.
If metal sheeting is used to hold the rods, the sheeting could be formed to have rods and bring the water into the gutter. This could also be done as a plastic or metal molding and look much like a hair comb with its teeth hanging out over the end of the gutter and the spine of the comb (above the teeth) attached to the roof above the gutter.
In order to test the embodiments discussed above, a work table was made to hold a roof section having a gutter section at the low end and a water flow device at the high end. The roof section can be held at different slopes and different type roofing was placed on the table and different flow rates were selected. Leaves and roof debris was placed between the water source and the gutter on the roof section and the results were observed under closely controlled conditions.
The testing work supports the efficacy of the embodiments described herein. Most of the testing used one-sixteenth inch diameter rods and flat rods turned on edge (thinnest edges up and larger surfaces facing the next-adjacent rod). The testing showed that holding the rods parallel to one another is very important. The rods need to spring back to their original positions if they are deformed downwardly against the far edge of the gutter or laterally to a non-parallel relation. Furthermore, the capillary attraction of water to and between the rods increased as the rods were moved closer together and increased as the diameter of the rods increased.
The GLSB method and structures described herein show promise, because during testing the GLSB embodiments cleared a range of debris made up of small and large leaves, seed pods, twigs, and pine needles with a minimum of small debris going into the gutter. The amount that went into the gutter was cleared by normal flow of water in the gutter to the down spout. GLSB rods can be incorporated into a gutter so that the rods are manufactured along with the gutter and the two are integral. Different climate locations and debris types could call for different solutions to reduce cost and maintenance.
Applicant's studies show the cantilevered ends of the GLSB rods allow the debris to clear the end of the gutter. However, when the lower edges of the distal ends of the rods are held against the upper, outer edge of the gutter, leaves and debris are held back and do not slide off the ends of the rods. The studies thus far show that the slide made of thin rods perpendicular to the gutter's length and held above the outside edge of the gutter work better than the surface tension leaf rejection method that is conventional.
The water was brought below the rods of some embodiments by having the rods pass through metal or plastic sheeting as described above. The rods of other embodiments have been attached through plastic piping (having a one inch diameter and a one-eighth inch wall) and in others into one-quarter inch diameter solid rod stock. The sheeting can be part of the drip edge on the roof's edge, the sheeting can be part of the one inch diameter pipe between the drip edge and the gutter, and the sheeting can be part of the one-quarter inch rod on the roof itself.
Both the one inch diameter piping and the one-quarter inch solid rod can be mounted using a fastener that forms a hinge means for pivoting the GLSB rods to access the gutter for cleaning. This can be by rotating the pipe or rod to lift the GLSB rods. Stops can be put on the pipe or holding rod to define the maximum down and/or up position.
Rods can be formed by cutting a sheet along spaced, parallel lines and twisting the formed flat segments 90 degrees. Although this is an inexpensive method for forming GLSB rods, there can be problems with water attraction (capillary action) and holding the rods parallel.
The method of attaching the rods (teeth) to the back of the gutter, when the “comb” design is being used, will now be described in detail. For a new gutter system using GLSB or for a flat, high-back gutter already in use, a holding device 360 can be attached to the upper part of the back edge of the gutter 314 that allows the GLSB to be snapped in place, moved up or taken off easily, as shown in FIG. 6 . The holding device 360 can be molded out of plastic or metal that is attached to a conventional gutter 314 , or the holding device 360 can be extruded as part of a plastic gutter. In the illustrations of FIGS. 7 and 8 , the pivot structure 400 defines a C-shaped opening 402 for the cylindrical frame 408 of the comb-shaped device 412 to snap into. The lower tip 404 of the “C” provides a limit for downward movement of the rods of the device 412 , because the rods will rest against the lower tip 404 and maintain the vertical spacing between the rods and the far edge of the gutter. In order for the rods to move any lower, they must be bent. However, the rods can be lifted upwardly for cleaning as shown in FIG. 8 in dashed lines.
As shown in FIG. 8 , the frame 408 of the comb-shaped structure 412 is mounted in the holding device 400 in such a way (such as a friction fit) that pivoting up or down is possible when a sufficient force is applied. However, it is preferred that downward pivoting does not occur without deliberately moving the rods, in order to maintain the space between the lip of the gutter 414 and the bottom of the rods. As shown in FIG. 9 , the comb can be molded or made from wire 500 attached to a dowel 502 , and that dowel 502 can serve as a frame and be inserted in the holding device 400 as shown above, with the wire 500 serving as the rods.
As shown in FIG. 9 , the wire 500 has curved ends 504 that join adjacent pairs of wire. This means that any large debris sliding down the wires can catch in the curved ends 504 and not fall off the structure. It is preferred to either cut the curved ends off back to the straight portions of the wire 500 , or bend the curved ends downward toward the gutter (not visible) and back to allow the debris to clear the curved ends. The curved ends can form legs that support the wire 500 at the far edge of the gutter when the wire contacts the far edge of the gutter.
This detailed description in connection with the drawings is intended principally as a description of the presently preferred embodiments of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the designs, functions, means, and methods of implementing the invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and features may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention and that various modifications may be adopted without departing from the invention or scope of the following claims. | A gutter protecting apparatus includes a plurality of substantially parallel rods extending in a downward slope from near a roof edge to and beyond the far side of the gutter. The rods extend substantially perpendicular to the gutter's length and to a frame to which the rods connect at the upper edge. Preferably, the lower rod ends are spaced above and slightly beyond the far edge of the gutter to allow debris to pass the gutter without catching. Legs can extend down from some rods to the gutter's far edge to provide support. The apparatus can be pivotably mounted to the roof, the fascia or the gutter, permitting access beneath. The apparatus forms a cage-like covering over the gutter to exclude matter and small creatures, while allowing the liquid to flow past. Sunlight bypassing the rods and movement of air through the gutter make the water exiting the downspout cleaner. | 4 |
BACKGROUND AND SUMMARY OF THE INVENTION
The instant invention concerns an open-end spinning machine with a plurality of spinning stations located next to each other, having spinning elements driven collectively by a collective drive, and a process for thread joining on such a machine. In a known process, thread joining is carried out at reduced rotor speed, whereby the speed of fiber feeding and thread drawoff is adapted to this reduced number of RPMs of the rotor in such a way that the rotor speed ratio between the individual spinning elements is maintained at all times as it was preset for spinning production (German Pat. DE-OS No. 2,058,604, corresponding with U.S. Pat. No. 3,791,128). In order to attain this reduced rotor speed for thread joining at an individual spinning station in a simple manner when a plurality of spinning stations are driven collectively, the RPM's of the spinning rotor are scanned during run-up to production speed, and the thread joining process is started when the reduced number of RPMs is reached (German Pat. DE-AS No. 2,341,528, corresponding with U.S. Pat. No. 4,276,741 and DE-OS No. 2,610,575). However, the time available here and also the number of RPMs are not constant and vary in particular depending upon the running condition of the machine and of the individual rotor bearings. This not only influences the success of thread joining but also the speed and the quality of the joints.
Another known method consists in providing a step-up gearing between a drive belt and the rotor shaft for each spinning station and to preset two step-up ratios which can take over the driving of the spinning rotor alternately for thread joining or for production, as desired (German Pat. DE-OS No. 2,754,785, Japanese Pat. JP-PS-AS No. 21.966/84. Although rotor speed is thus reduced by a certain percentage for thread joining, this speed is always in a fixed relation to the production speed of the rotor. Thus the rotor speed for thread joining is different from and dependent from production speed.
The instant invention is based upon the surprising finding that the rotor speed for thread joining should not always be uniformly low, and should not always be reduced at a fixed ratio to the production speed of the rotor. The correct rotor speed for thread joining depends in each case upon the fiber material to be spun.
It is therefore the objective of the instant invention to avoid the disadvantages cited above. In particular, it is the objective of the instant invention to create a simple device by means of which a second rotor speed can be attained individually at a spinning station whereby it is possible to select said rotor speed in a simple manner in accordance to spinning conditions, and independently from the production rotor speed.
It is a further objective of the instant invention to create a thread joining process which improves successful piecing and the quality of the joints.
This objective is attained by the invention by providing, in addition to the collective drive, a stationary auxiliary drive which can be attributed to (i.e. associated with) the spinning element of each spinning station individually, instead of the collective drive. The speed of this second, stationary auxiliary drive which can be individually attributed to the spinning elements can be adapted as needed to any given fiber material, rotor diameter, etc. at a central location. Since this adjustment is carried out once per machine or per section, such an adaptation to a different type of fibers is economical from the standpoint of both time and material. The auxiliary drive is preferably located in the end frame of the machine.
The concept of "spinning element", in the sense of the instant invention, shall include all elements required for the spinning process. This is preferably a spinning rotor, but this concept should also comprise, in addition to a spinning rotor, a pair of friction rollers as well as other elements of a spinning station, for example the feed roller, etc.
According to a preferred embodiment of the object of the invention, the auxiliary drive is equipped with a drive motor that is separate from the collective drive. In this way the speed ratio between the two drives can be controlled very simply.
In an alternate embodiment of the invention however, a single drive motor can be provided also and can be attributed to the collective drive directly and to the auxiliary drive via a step-up gear.
In the sense of the invention the concept "step-up gear" is to be understood to mean a gear to step up speed, as well as to reduce speed.
The step-up ratio of the step-up gear can be set as a function of production speed and of the material to be spun, preferably between 95:100 and 75:100, so that the rotation speed of the spinning elements is merely in about the range of and 5% to 25% lower for thread joining than for production.
In many applications a gradual acceleration of the spinning aggregate from thread joining speed to production speed is not required. According to an aspect of this invention, the step-up gear (if present) is preferably equipped with a stepped speed pulley for such case.
The adjustment of the step-up gear is preferably continuous, and a further advantage is achieved if the speed of the auxiliary drive can be increased to the speed of the collective drive.
Experience has shown that even when the fiber feeding device suddenly releases the fiber tuft, the fibers do not reach the spinning element jerkily but that the fiber quantity reaching the spinning element increases according to a run-up curve until finally the fiber quantity per time unit coming into the spinning element is steadily as preset by the feeding speed of the fiber feeding device. Therefore it is preferable to accelerate the auxiliary drive not randomly but according to this run-up curve of the fiber quantity reaching the spinning element upon release of the fiber feeding device.
It is also useful for many purposes if the direction of rotation of the auxiliary drive can be reversed. This applies especially to the friction rollers and the feed roller.
Preferably the auxiliary drive is controlled through controls located on a service unit travelling alongside a plurality of spinning stations, whereby the entire thread joining process is controlled through said controls. In a preferred embodiment of the invention the controls on the service unit which control the auxiliary drive are also controllably linked to an auxiliary driving device for the mechanism which draws off the thread during the thread joining process. In this way, the thread draw-off speed can be adjusted to the rotational speed of the spinning element and to the thread joining process. At the same time it is absolutely possible to control the thread draw-off speed asynchronously to the rotational speed of the spinning element, for example in order to give the thread temporarily greater twist for the thread joining process.
According to a preferred embodiment of the invention, the collective drive is equipped with a main drive belt to drive a plurality of spinning elements simultaneously and the auxiliary drive is equipped with an auxiliary drive belt to drive a spinning element individually. The main drive belt drives all normally operating spinning elements at the same speed during production. By contrast, spinning elements in which a thread is to be joined anew are separated from this main drive belt during the thread joining phase and are instead driven individually by the auxiliary drive belt which, in turn, is driven at a speed different from that of the main drive belt. Thus any spinning element at which a thread is to be joined is operating at a rotational speed different from that of the spinning elements operating undisturbed at production speed.
For reason of material and space savings, the auxiliary drive belt can be made narrower than the main drive belt. Since the auxiliary drive belt only drives one single spinning element at a time, functional reliability is nevertheless ensured.
The selection of the desired drive, in each case, for a specific spinning element is made preferably by means of an individual switch-over device which alternately attributes (i.e. drivingly couples) one of the two drives to the spinning element. This switch-over device can be borne upon by an elastic element so that the main drive belt can be brought to bear against a drive element connected to and rotating with the spinning element, or can be held against said drive element when the switch-over device is enabled (i.e. released).
Preferably a two-armed switch-over lever is provided for each spinning station. This lever is equipped with a main contact roller on one arm and with an auxiliary contact roller on the other arm for the alternate application of the main drive belt or of the auxiliary drive belt against the spinning element. In this manner a simple embodiment in accordance with the object of this invention is achieved.
In order to avoid additional operating elements per spinning station, the switch-over is preferably linked in a controllable manner to a brake for the spinning element. This controllable linking can be achieved in various ways. In a preferred embodiment of the device according to invention the brake is attributed to (i.e. comprised of) a brake lever supported by the switch-over lever.
Simple control of the spinning element brake and of the switch-over device is achieved according to this invention by equipping the brake lever with at least one carrier, and through the fact that said brake lever, by moving from a neutral spinning position into its first end position constituting the braking position, lifts the main contact roller from the main drive belt and, by moving into its other end position constituting the thread joining position, causes the auxiliary contact roller to be applied against the auxiliary drive belt.
According to a preferred embodiment according to the object of this invention, the brake lever is pivotably supported on bearings by its one end on the main drive roller supporting shaft of the two-armed lever, is at the same time linked to an activating device by its free end, and is equipped with a braking surface between its two ends. It can be moved into its braking position so that the brake lever, after reaching its braking position and continuing its movement, causes pivoting of the switch-over lever as a result of the application of its braking surface against the spinning element.
It is advantageous if the spinning element is located in immediate proximity of the main contact roller, and further if the distance between the free end of the brake lever (used and for activation) and the brake (which can be brought to bear upon the spinning element) is greater than the distance between the brake and the bearing shaft.
In a preferred embodiment of a device according to this invention, the brake lever is equipped with an intermediate lever which, together with the switch-over lever, is pivotably supported on bearings on a common shaft. One end of said intermediate lever is in gearing contact with the activating device and overlaps the two-armed lever of the switch-over device on its side opposite to the spinning element. The other end of said intermediate lever is articulatedly linked to the brake lever which reaches under the two-armed switch-over lever on its side towards the spinning element. In this manner, in spite of minimal switching paths, only little switching force is required.
In order to lower the drive forces for activation of the brake and of the switch-over device by properly selecting lever arms and drive moments, and in order to raise operational security the brake lever is preferably supported on bearings independently from the two-armed lever of the switch-over device, whereby the brake lever is equipped with one carrier on each side of the pivoting axis of the two-armed switch-over lever for the pivoting of the two-armed switch-over lever into one or the other pivoting direction, as desired. Because of the independent bearing support of the brake lever its pivoting point can be selected so as to render the brake's movement essentially linear when it is moved into or out of braking position. This increases operational security of the device.
In a further, preferred development of such an embodiment of the invention, the shaft of a spinning element in the form of a spinning rotor is supported on bearings in a wedge-shaped gap formed by supporting rings, while the brake lever can be moved in its braking movement in the direction of said supporting rings. Under such conditions, space utilization is especially good if the shaft of the spinning rotor is supported by a single pair of supporting rings on the side towards the spinning rotor, in relation to the drive belt and the auxiliary drive belt, and is supported by a combined axial/radial bearing on the side away from the spinning rotor.
In a fully automatic open-end spinning machine, a service unit is normally provided for travelling alongside a plurality of spinning stations, and which can interact as desired with each spinning station. It is advantageous in such instances if the service unit is equipped with a drive device to activate the switch-over device, said drive device being controlled by means of a control program.
The switch-over device is preferably provided at each spinning station with a control lever for attribution (i.e. application) of the collective drive or of the central auxiliary drive, as desired, to a spinning element, said control lever being pivotable in relation to a hinged cover covering the spinning station. This control lever allows for simple control of the device according to this invention, especially when, in further suitable embodiments according to the object of this invention, the control lever is able to assume three relative positions with respect to the cover, whereby it is flush with the cover in its basic position, pivots away from the cover in its braking position, and is pushed into the cover in its thread joining position.
In order to allow for simple manual control of a device according to this invention, a locking device is suitably provided for the control lever. The operator needs both hands to lift off the bobbin, during the thread joining process, for the search and back-feeding of the thread, for the lowering of the bobbin and to enable (or release) fiber feeding. The locking device ensures that the operator does not also have to hold the control lever in its thread joining position during the thread joining process.
If, in further embodiments according the object of this invention, the locking device is subjected to elastic pressure in such way as to permit the movement of the control lever into the thread joining position while preventing its return into the production position, and if the locking device is furthermore equipped with a controllable solenoid, it becomes possible to control the enabling (i.e. releasing) of the control lever, so that it can return into the production position in a simple manner by means of an electric switch. In such case, the switch is preferably the switching device controlling fiber feeding, whereby the solenoid is then controllably linked to this switching device controlling fiber feeding.
To prevent untimely wear of the main contact roller and of its bearing because of possible imbalance in the spinning element, it is useful to equip the switch-over lever with a damping device. The latter is suitably made in the form of a frictional damper located preferably in the bearings of the switch-over lever.
The above-described device in the assembly makes it possible to carry out thread joining in the simplest and optimal manner. It is especially important for uniformity of yarn characteristics to maintain essentially constant rotor speed during the spinning process. Yarn production begins as early as during the thread joining process, and for this reason, according to the instant invention, thread joining is carried out preferably at a rotor speed that is close to the rotor speed for production, whereby the rotor speed for thread joining should be selected as high as possible as a function of the type of fiber material to be spun, of the rotor diameter, etc.
It has been shown here, as a rule, that optimal results are obtained when the RPMs of the rotor for thread joining are 5% to 25% below the RPMs of the rotor during production.
Use of a device provided in accordance with this invention makes it possible to impose a defined thread joining speed for a desired period of time and at the desired moment upon each spinning element in a simple and reliable manner, without requiring a separate drive for the spinning element at each spinning station. Thus a predetermined thread joining program can be used and the reliability of thread joining is considerably increased in comparison with the known state of the art, while joints become cleaner and stronger.
BRIEF DESCRIPTION OF THE DRAWINGS
Several examples of embodiments in accordance with this invention are explained through the specification below, taken in conjunction with the appended drawings, in which:
FIG. 1 is a schematic top view of an embodiment of the invention with two drive belts as well as with a switch-over lever to alternately take the drive belt in and out of action.
FIG. 2 shows a variation of the embodiment of the invention in top view.
FIG. 3 is a schematic representation of a further variation with a continuously adjustable step-up gear according to the invention;
FIG. 4 is a schematic front view of a device coupled to a brake according to this invention to selectively drive a spinning rotor at production speed or at a lower thread joining speed.
FIG. 5 is a front view of a variation of the device shown in FIG. 4.
FIG. 6 shows a spinning station designed according to this invention as well as a service unit interacting with said spinning station, in schematic cross-section.
FIG. 7 shows a damping device for a device in accordance with this invention, in cross-section.
FIGS. 8-10 are schematic front views of the preferred embodiment of the invention with a switch-over lever and a brake level, supported independently of the former, in thread joining, spinning or braking position.
FIG. 11 is a schematic side view of a spinning station with a pair of friction rollers and a feeding roller, with a first and a second drive respectively.
FIG. 12 is a schematic side view of a spinning station cover and of a control lever, particularly well suited for manual control of the device according to invention.
FIGS. 13A-13C represent explanatory diagrams summarizing particularly the present thread joining process as related to the exemplary devices of FIGS. 6 and 12.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is at first explained through the example shown in FIG. 1. At each spinning station S a spinning element in form of a spinning rotor 1 is provided. The spinning rotor 1 is supported on bearings by means of a shaft 10 and is driven via said shaft by means of a main drive belt 5. This main drive belt 5 is a component of a collective drive 56 by which the spinning rotors 1 of a plurality of spinning stations S located next to each other are driven via said main drive belt 5 simultaneously with the spinning rotor 1 of the shown spinning station S. The main drive belt 5 is itself driven by a main motor 54 in the machine drive framework 500 which is controlled from a controlling device 6 as desired.
In addition to the mentioned collective drive 56, a stationary auxiliary drive 57 is also provided. It is equipped with an auxiliary drive belt 53 which extends alongside the machine, next to the main drive belt 5 used to drive the spinning rotors 1 at normal spinning speed. While the main drive belt 5 is destined to drive a plurality of spinning rotors 1 collectively, the auxiliary drive belt 53 is destined to drive only one spinning rotor 1 at a time, in the thread joining phase. For this reason the auxiliary drive belt 53 need not be made as solidly, so that its width can be narrower than that of the main drive belt 5. This has a beneficial effect on space utilization.
FIG. 1 shows a step-up gear 3 with a stepped speed pulley 34 as the central device for the auxiliary drive belt 53. Said speed pulley 34 has a first linear segment 340 of greater diameter to drive the main drive belt 5 and a second linear segment 341 of smaller diameter to drive the auxiliary drive belt 535. The diameter ratio between the linear segments 340 and 341 determines the gradation between the rotational speed of the spinning rotor 1 for production and that for thread joining.
Shaft 10 is supported by its end towards spinning rotor 1 in the nip of a pair of support rollers 11. Its end 100 away from spinning rotor 1 is of reduced diameter and is supported by a combined axial/radial bearing 13 (FIG. 6).
A switch-over device 2 with a two-armed switch-over lever 20, supported pivotably on a shaft 201, is provided at each spinning station S. The switch-over lever 20 is provided with a main clamping roller 211 on one arm 230 which can be brought to bear against the main drive belt 5, while the other arm 231 of the switch-over lever 20 is equipped with an auxiliary clamping roller 212 which can be brought to bear against the auxiliary drive belt 53.
Between the individual spinning stations S are conventional supporting rings or discs 50 and 51 (FIG. 8) which lift the main drive belt 5 or the auxiliary drive belt 53 from shaft 10 of the spinning rotor 1 upon being enabled by the main clamping roller 211 or the auxiliary clamping roller 212. In this way, only one of the belts 5 or 53 at a time is in contact with shaft 10 of the spinning rotor 1 which is forced into this contact by the corresponding clamping roller 211 or 212.
When a thread is to be joined individually at a spinning station S because of thread breakage or some other reason, the switch-over lever 20 at the spinning station S concerned is pivoted (in a manner to be explained in further detail hereinbelow) so that the main clamping roller 211 releases the main drive belt 5, allowing the supporting discs 50 and 51 to lift this main drive belt 5 off the shaft 10 while the auxiliary clamping roller 212 applies the auxiliary drive belt 53 against shaft 10 of the spinning rotor 1. The spinning rotor 1 of this spinning station is thus separated from the collective drive constituted by main drive belt 5 and is now driven at a lower thread-joining speed.
Upon completion of the thread-joining operation the switch-over lever 20 switches back to normal spinning speed through release of auxiliary drive belt 53 (which now lifts away from shaft 10) by the auxiliary clamping roller 212, and through the application of the main drive belt 5 against shaft 10 of the spinning rotor 1 by means of the main clamping roller 211.
The switch-over lever 20 thus brings either the main drive belt 5 or the auxiliary drive belt 53 to bear upon spinning rotor 1 as selected.
The switch-over lever 20 can be controlled in different ways, as shall be explained further on through different examples. In the simplest case the switch-over lever is pivoted manually.
The thread joining speed is determined by changing the step-up ratio and this is achieved by appropriate selection of the stepped speed pulley 35 in the drive frame 500 of the machine. In this way the speed ratio is set for all of the spinning station S of the machine, so that the desired adaptation can be achieved quickly when batches, yarn numbers or rotors are replaced.
FIG. 2 shows a variation of the central drive for the auxiliary drive belt 53 shown in FIG. 1. This central drive makes it possible to control the run-up of the speed of auxiliary drive belt 53. In this embodiment the main drive belt 5 as well as the auxiliary drive belt 53 are driven from a central location, i.e. drive frame 500 which is equipped for that purpose with an auxiliary drive motor 530 in addition to the above-mentioned main motor 54. The main drive belt 5 is then driven by the main motor 54 via a pulley 540. The speed of motor 54 and thereby of the main drive belt 5 is determined by the control device 6 already mentioned in connection with FIG. 1. The auxiliary drive belt 53 is driven by the auxiliary drive motor 530 via a pulley 531. The auxiliary drive motor 530 is provided with a control device 63 by means of which the speed of the auxiliary drive motor 530, and thereby of the auxiliary drive belt 53, is selected.
The auxiliary drive motor 530 drives the auxiliary drive belt 53 at a speed which is lower than the speed of main drive belt 5. Experience has shown that, depending upon the set rotational speed of the spinning rotor 1 and its diameter, a rotor speed of the spinning rotor 1 from 75% to 95% of the normal production speed of the spinning rotor 1 ensures especially secure thread joining. For this reason the speed difference is selected so that the speed ratio between thread joining speed and spinning speed lies within a range from 95:100 to 75:100.
The speed gradation is preselected by appropriate setting of the control devices 6 and 63. Provision can here be made to increase the speed of the auxiliary drive motor 530 by means of control device 63 after completion of thread joining until the main drive belt 5 and the auxiliary drive belt 53 run at the same speed. To achieve this, a coupling (not shown) can be provided between the control devices 6 and 63 which could also take into account possible differences in dimension between the pulley 540 and the pulley 531.
Thread joining cannot always be carried out optimally at the same thread joining speed. Depending upon the fiber material to be spun, upon the yarn number, the rotor diameter etc., different thread joining speeds are to be selected for thread joining so that perfect joints are obtained, from the point of view of strength as well as looks. For this reason the speed of the auxiliary drive motor 530 is selected in such a way, by comparison to the main motor 54, and depending upon the given conditions (essentially influenced by the above-mentioned factors) that the speed of the spinning rotor 1 is 25% to 5% lower than the production speed imparted to the spinning rotors 1 by means of the main drive belt 5.
The higher the rotational speed for thread joining, i.e. the less it deviates from production speed, the less does the character of the joint and of the following yarn segment differ from the remainder of the yarn. For this reason it is advisable to carry out thread joining at as high a rotor speed as possible. Depending upon the elasticity of the fiber material however, the same number of RPMs cannot always be selected for the spinning rotor 1. If the speed is too high, the yarn being formed is over twisted and therefore twisted off, so that the thread breaks. If the rotational speed is too low, the joint will differ too much from the remainder of the yarn. Especially when using living fiber material, such as cotton or wool, the thread joining operation is therefore preferably carried out at a rotor speed merely 5% to 25% below the rotor speed for production.
By running up the rotor speed from thread joining speed to normal spinning speed before the transfer or rotor drive from the auxiliary drive belt 53 to the main drive belt 5, smoothmenss of transfer is ensures which is therefore gentle on the yarn. As a result there are fewer breaks in the yarn.
It has been shown that the fibers do not reach the spinning rotor 1 jerkily after thread joining. The fibers retained in the feeding device (not shown) in the form of a fiber tuft are of different lengths and are therefore not released at the same time when the feeding device is again switched on. At first there are only a few fibers being conveyed from the opening device (also not shown) to the spinning rotor 1. In time there are more fibers until finally the normal feeding quantity reaches the spinning rotor 1. The fiber quantity coming into the spinning rotor 1 increases here along a run-up curve the course of which is influenced by several factors, such as fiber length, feeding speed, etc.
The run-up curve of the auxiliary drive motor 530, controlled via control device 63, can be adapted to the run-up curve of the fiber quantity arriving into the spinning rotor 1 after thread joining in such a way that as constant a relationship as possible is maintained between the two run-up curves.
In the embodiment shown in FIG. 3 the pulley 531 of the auxiliary drive belt 53 is also driven (as shown in FIG. 1) from the main drive motor 54 with intercalation of a step-up gear 3. For this purpose a cone wheel 55 of a cone wheel gear is located on shaft 541 on which the pulley 540 for the drive belt 5 is rigidly supported for rotation with shaft 541. The second cone wheel 550 of this gear is located on a shaft 532 which also supports the belt pulley 531 for the auxiliary drive belt 53. A belt 551 loops around the two cone wheels 55 and 550 together, said belt being movable parallel to the shafts 541 and 532 by means of a control mechanism 630.
In a manner similar to that described for the two motors 54 and 530 (FIG. 2), the speed of the auxiliary drive belt 53 can be accelerated here too until it reaches the speed of the drive belt 5 after completion of a thread joining operation.
The control mechanism 630, and possibly also the control device 6, are controllably linked to a service unit 64 travelling alongside the spinning machine. Trailing cables can be used for example, to ensure power supply to the service unit 64. The above-mentioned acceleration of the auxiliary drive belt 53 can thus be controlled from the travelling service device 64.
A predetermined initial position of the belt 551 can be set by the control mechanism 630. This initial position can in turn be used to determine the step-up ratio between the drives for the main drive belt 5 and for the auxiliary belt drive 53 while taking into account possible diameter differences between the pulleys 540 and 531.
As shown in FIGS. 3 and 11, the service unit 64 supports an auxiliary drive roller 640 which is driven in a conventional (not shown) manner from the service unit 64. This auxiliary drive roller 640 can be applied against a bobbin 70 at the spinning station S at which the thread is to be joined during the thread joining phase in order to feed the thread back to the spinning rotor 1 for joining, and to draw off the thread again from the spinning rotor 1 after completion of the thread joining operation. The drive of the auxiliary drive roller 640 and the control mechanism 630 are controllably linked to each other via the service unit 64 so that a constant ratio between rotor speed and thread draw-off speed may be maintained.
In the device shown in FIG. 1, the thread joining speed is also selected by means of a switch-over lever 20 provided at each spinning station S individually.
FIG. 4 shows a front view of the switch-over device 2 with switch-over lever 20 shown in FIGS. 1 and 2. Such a switch-over device 20 is provided individually for each spinning station S. In this embodiment the arm 230 with the main clamping roller 211 is provided with a pressure spring 22 which normally holds the main drive belt 5 in contact against shaft 10 of the spinning rotor 1 when the switch-over device 20 is enabled by means of the main clamping roller 211.
According to the embodiment of FIG. 4 the switch-over device 20 is connected controllably to a brake 4 for the spinning element. For this purpose a brake lever 44 is pivotably supported on shaft 213 of the main clamping roller 211, whereby a tie rod 8 attaches at the free end of said brake lever. The brake lever 44 is installed at an angle to arm 230 of the switch-over device 20. Its free end is closer to the plane of the main drive belt 5 than arm 230 of lever 20. This arm 230 is equipped with a stop 232 on its side towards the brake lever 44, whereby a carrier 440 installed near the free end of brake lever 44 can be brought to rest against said stop 232.
The brake lever 44 is provided with a brake lining 441 near shaft 213 which can be brought to bear against shaft 10 of the spinning rotor 1, also located in immediate proximity of the main clamping roller 211. The position of brake lever 44 with brake lining 441 subdivides brake lever 44 into a shorter lever arm 443 which faces the main clamping roller 211 and a longer lever arm 442 facing the free end, at which the tie-rod 8 attacks.
FIG. 4 shows the device in spinning position, in which the main drive belt 5 is in bearing contact with shaft 10 of the spinning rotor 1. If the spinning rotor 1 is to be shut down, the brake lever 44, together with its brake lining 441, is moved by means of tie rod 8 in the direction of support roller or disc 11 (see FIGS. 6 and 8-10), so that lining 441 is applied against the shaft 10. Further movement of the tie rod 8 causes the brake lever 44 to act as a two-armed lever supported on shaft 10 of spinning rotor 1 and lifting the main clamping roller 211 with its lever arm 442 to the extent that the main drive belt is lifted away from shaft 10 by the supporting discs 50 and 51 (see FIG. 8). Switch-over lever 20, is however not yet moved to such an extent so as to bring the auxiliary belt 53 to bear against the shaft 10 of spinning rotor 1 by means of auxiliary clamping roller 212.
If the lower rotor speed is to be selected now for thread joining, the tie rod 8 is moved against the switch-over device 20. At the same time the carrier 440 of brake lever 44 comes to bear against the stop 232 of the switch-over device 20. The latter is then pivoted so that the main clamping roller 211 releases the main drive belt 5 while the auxiliary clamping roller 212 presses against the auxiliary drive belt 53. The main drive belt 5 is lifted away from shaft 10 by the supporting discs 50 and 51 while the auxiliary drive belt 53, which is driven by the stepped speed pulley 34 (FIG. 3), by the auxiliary drive motor 530 (FIG. 1), or by the cone wheel gears 55, 550 (FIG. 2), at a slower speed than that of the main drive belt 5, comes to bear against shaft 10.
A movement of the tie rod 8, and thereby also of the brake lever 44 in one direction causes braking of the spinning rotor 1 and causes the main drive belt 5 as well as the auxiliary drive belt 53 to be simultaneously lifted away from shaft 10 while the movement of the tie rod 8 and brake lever 44 in opposite direction causes the main drive belt 5 to be lifted away from shaft 10 while the auxiliary drive belt 53 comes to bear against shaft 10.
As is shown in FIG. 4, arm 230 of the two-armed switch-over device 20 is spring loaded by a pressure spring 22, together with the main clamping roller 211, in such manner as to cause the switch-over device 20 to return into its spinning position when it is neither pulled nor pushed by the tie rod 8. In this spinning position the main clamping roller 211 presses the main drive belt 5 against shaft 10 of the spinning rotor 1 while the auxiliary clamping roller 212 releases the auxiliary drive belt 53 which is lifted away from shaft 10 through the action of the supporting discs 50 and 51 (see FIG. 8). By means of this pressure spring 22 (or some other elastic element) the main drive belt 5 is thus brought to bear against shaft 10 of the spinning rotor 1 (or some other drive element connected to and rotating together with the spinning rotor 1, such as for example a driving wharve) when the switch-over device 2 is enabled.
In the embodiment of FIG. 5 the brake 4 consists of a driven intermediate lever 45 and the actual brake lever 44. The intermediate lever 45 is located on the shaft 201 of the switch-over device 20 and its end on the side of auxiliary roller 212 engages the tie rod 8. Furthermore, this end of the intermediate lever 45 is provided with a carrier 450 which overlaps the arm 231 of the switch-over lever 2 on its side away from shaft 10.
The end of the intermediate lever 45 on the side of the main clamping roller 211 is in the configuration of a fork 451 and reaches around a pin 444 at the free end of the brake lever 44 supported on the shaft 213 of the main clamping roller 211. The intermediate lever 45 is thus articulately linked to the end of the brake lever 44 which is pivotably supported on the shaft 213 of the main clamping roller 211. Said brake lever 44 has a carrier 440 (as shown in FIG. 4) by which it can be brought to bear against the side of arm 230 of the switch-over device 20 facing spinning rotor 1, so that the brake lever 44, together with its carrier 440, reaches under arm 230 of the switch-over device 20.
Arm 231 of the switch-over device 20 is spring-loaded by means of a pull spring 220 so that the main clamping roller 221 moves the main drive belt 5 against shaft 10 of the spinning rotor 1 when the switch-over device 20 is enabled.
In this embodiment of the device the moving mechanisms of the tie rod 8 for the obtention of certain functions are reversed, in comparison with those shown in FIG. 4. When the tie rod 8 is lifted, carrier 450 of the intermediate lever 45 is lifted away from arm 231 of the switch-over lever 2 and the brake lever 44 is pivoted by the intermediate shaft 45 against shaft 10 of the spinning rotor 1. Spinning rotor 1 is thus stopped. When the movement of tie rod 8 continues, brake lever 44 bears upon shaft 10 which now constitutes a pivoting axis for brake lever 44 and lifts the main clamping roller 211 away from main drive belt 5 while bringing auxiliary clamping roller 212 into contact with the auxiliary drive belt 53.
When the tie rod 8 is pulled down, stop 450 of the intermediary lever 45 causes slaving of the switch-over lever 2 and presses auxiliary drive belt 53 against shaft 10 via its auxiliary clamping roller 212. The main drive belt 5 which is simultaneously released by the main clamping roller 211 is thereby lifted away from shaft 10 of the spinning rotor 1 by the supporting discs 50 and 51 (see FIG. 8).
When the tie rod 8 is in its starting position the two-armed switch-over lever 20 assumes the spinning position under the effect of the spring 220. Spinning rotor 1 receives its driving force in this position from main drive belt 5.
The tie rod 8 can be controlled by means of the device shown in FIG. 6. In this embodiment a spring 80 exerts constant direct or indirect pull upon tie rod 8 whereby it is kept in the position in which the brake lining 440 of brake lever 44 is lifted away from shaft 10. Tie rod 8 is connected to a two-armed lever 81, pivotable around an axis 810. The two-armed lever 81 is stopped by a control lever 82 pivotable around an axis 820. For this purpose, control lever 82 is provided with a drive fork 821 reaching around a roller 811 of lever 81. Control lever 82 is located in a slit 700 (FIG. 12) of a cover 7 of the spinning station 5 and can be moved in relation to same. As shown in FIG. 6, control lever 82 is in alignment with cover 7. In this position I the switch-over roller 20 assumes its spinning position in which the main clamping roller 211 holds the main drive belt 5 in contact with shaft 10 of spinning rotor 1.
If access is to be gained to the spinning rotor 1 for the purpose of maintenance, the rotor housing (not shown) is opened by unhinging the cover 7 (FIG. 6). This cover 7 simultaneously activates control lever 82 which is pivoted in direction of arrow 83 into position II and releases lever 81 at the same time.
Spring 80 thereby moves tie rod 8 so that brake lever 44 is brought into its braking position and switch-over lever 20 is brought into its neutral intermediate position, whereby neither the main drive belt 5 nor the auxiliary drive belt 53 are in contact with shaft 10.
Following maintenance, the cover 7 (FIG. 6) of the rotor housing (not shown) is closed again. The control lever 82 is left in the unhinged position or is brought into the unhinged position. The brake lever 44 thus again assumes a braking position.
In synchronization with the feed-back of the thread end into the spinning element the control lever 82 is then pushed in the direction of arrow 84, into position III within cover 7, against the force of a readjusting spring 822. At the same time the main clamping roller 211 is lifted away from the main drive belt 5 via tie rod 81 in the above described manner, and the auxiliary clamping roller 212 is pressed against the auxiliary drive belt 53 so that the spinning rotor 1 is now driven by said auxiliary drive belt 53.
It is also possible to control the movement of the control lever 82 manually or from the service unit 64, independently of or in interaction with the cover 7. This service unit 64 is equipped in conventional manner with a control panel 641 (FIG. 6) which controls the entire thread joining process. This control panel 641 is connected to a driving mechanism 642 for the unlocking mechanism 643 of control lever 82 or cover 7. The driving mechanism 642 can be made in form of a camshaft, for example, with a plurality of cams, one of these cams causing the return of cover 7 and/or of control lever 82 from position II into position I in which it lies flush with cover 7. This driving mechanism 642 is furthermore provided with a bolt 644 which is pressed against the control lever 82, pivoting it from its position I into position III against the force of the readjustment spring 822, to bring about the reduced thread joining speed. In this way the driving mechanism 642 installed in the service unit 64 serves to control the switch-over lever 20 in such manner as to stop the spinning rotor 1 via unlocking device 643, to drive said spinning rotor 1 at reduced rotor speed for thread joining and to drive it at normal production speed in a manner not shown.
The above described embodiment of the device used to control the drive of a spinning element is especially suited for control via a service unit 64 which travels alongside the spinning machine.
The operator needs both hands in manual thread joining to feed the thread back into the spinning rotor 1 and to enable fiber feeding at the precisely right, predetermined time. The operator is thus unable to keep the control lever 82 pushed in the direction of arrow 84, as the service unit 64 does it in the embodiment shown in FIG. 6.
In order to be nevertheless able to control the rotor speed for the thread joining process in a simple way, when a machine is to be controlled manually, the device shown in FIG. 6 is adapted according to the variation of FIG. 12. In this case a locking device 85 is provided for the control lever 82 to hold it back in thread joining position III. So that the locking device 85 does not have to be handled when the control lever 82 moves from production position I (see FIG. 6) into thread joining position III and when it moves back into production position, the locking device 85 is equipped with a spring loaded catch 850 which gets out of the way of the arriving control lever 82 and which catches behind it when the spinning position III is reached. A controllable solenoid 851 on catch 850 enables the control lever 82.
In the embodiment shown, a switching device 852 for the fiber feeding device 72 (see FIG. 11) is installed on the cover and is activated by means of a push-button 853. The switching device 852 is controllably connected to the above-mentioned fiber feeding device 72 and with solenoid 851 via a control device 854.
For thread joining, the control lever 82 is brought into thread joining position III, where it is secured by the catching catch. The spinning rotor 1 is thus driven in the described manner and at a lower speed. The thread is fed back up to the collecting surface of the spinning rotor 1 in a known manner (not shown). Similarly, fiber feeding to the spinning rotor 1 is switched on in a known manner at the desired moment by activating push button 853. When the thread joining process is completed and the conventional (and therefore not shown) thread monitor ascertains that normal spinning tension has been reached, the push button 853 is released.
At the moment of release of push button 853 the control device 854 briefly excites the solenoid 851. Said solenoid releases the control lever 82 so that it is returned to its production position I by the readjustment spring 822 and is held there by another, not shown stop. The spinning rotor 1 is thus driven once more at full production speed.
If thread joining was unsuccessful, the control lever 82 is again brought into its thread joining position III and the thread joining process is repeated.
As can be seen in FIG. 6, the control lever 82 must pass through production position I in its movement from maintenance or braking position II into thread joining position III. This raises the possibility of a particularly advantageous acceleration process, as discussed with reference to FIG. 13. FIGS. 13 A, B, and C illustrate rotor speed V R , the degree of fiber feeding V S , and the thread draw-off speed V A , all in a relative time line fashion, respectively.
As previously discussed, during maintenance control lever 82 assumes position II until the maintenance procedure (for example, a cleaning of spinning rotor 1) is concluded. At an arbitrary time A, control lever 82 is then brought from maintenance position II into production position I, in which the spinning rotor 1 is driven by the main drive belt 5. Spinning rotor 1 is accelerated in this manner. As soon as it has reached its rotational speed for thread joining (generally somewhere in time period B), which is predetermined as the drive speed of the auxiliary drive belt 53, control lever 82 is moved into thread joining position III.
The general period A to B may be preset in control device 641 (FIG. 6) of the maintenance device 64. Spinning rotor 1 will however not always reach the precise rotor speed V a for thread joining within a prescribed period of time, but will deviate within certain tolerance values upwards or down from this rotor speed V a due to the manufacturing tolerances, condition of the rotor bearings, etc. This is represented in FIG. 13 by the different dotted lines on the V a curve.
As specified above, in the thread joining position III, the main drive belt 5 is lifted away from shaft 10 of the spinning rotor 1 and the auxiliary drive belt 53 is instead brought into contact with this shaft 10. Thus, the auxiliary drive belt 53 maintains the spinning rotor 1 at the thread joining rotor speed Va basically established with the acceleration period under the drive power of main belt 5. If the spinning rotor 1 did not yet reach such thread joining rotor speed V a under the temporary acceleration of position I described above, or if it has already exceeded it somewhat, the auxiliary drive belt 53 brings spinning rotor 1 more precisely to such thread joining rotor speed V a .
At the thread joining rotor speed V a , the usual operating phases then required for subsequent actual joining, such as switching on fiber feeding (see curve V s of FIG. 13B), feedback of the thread into spinning rotor 1 (see time period V F of FIG. 13C), and renewed drawing-off of the thread (see curve V A of FIG. 13C), occur in the usual manner at thread joining rotor speed V a . In further coordination therewith, control lever 82 is released from thread joining position III (generally around relative time C), so that it returns into production position I under the influence of the readjusting spring 822, as described above. The auxiliary drive belt 53 is thereby lifted from shaft 10 of the spinning rotor 1 and the main drive belt 5 is re-applied to shaft 10. The spinning rotor 1 is thereby accelerated from the thread joining rotor speed V a to the production rotor speed V p , all as outlined above, particularly with reference to FIGS. 6 and 12.
The preceding description, drawn from the structure and operation of devices such as in present FIGS. 6 and 12, shows that rotor acceleration is substantially effected with the wider, stronger main drive belt 5, while the narrower and much weaker auxiliary drive belt 53 does not have to effect any change in speed, aside from some minor speed corrections. Auxiliary belt 53 merely has to maintain spinning rotor 1 at the thread joining rotor speed V a generally accelerated to with main belt 5. This accounts greatly for a long life of the auxiliary drive belt 53.
As a rule the deviations from the preset drive rotor speed V a , occurring at the time of drive transfer to belt 53 from main drive belt 5, are so minimal that they can be tolerated without danger and will not overload auxiliary drive belt 53. However, if even corrections of the thread joining rotor speed V a effected by auxiliary drive belt 53 are to be avoided, spinning rotor 1 can be equipped with a device to monitor its speed. In such manner, it is possible to precisely time movement of control lever 82 by the maintenance service unit 64 so that such corrections are no longer necessary
In practice it may not be completely possible to avoid deposits of impurities in the collecting groove of the spinning rotor 1, which may provoke an imbalance of the spinning rotor 1. In order to avoid increased wear of the main clamping roller 211 of the switch-over lever 20 and of its bearings as a result of such imbalance, said switch-over lever 20 is equipped with a damping device 9 in the shown embodiment. As shown in FIG. 1, the damping device 9 is made in the form of a frictional damper which is equipped with a rubber bushing 90 in the shown embodiment.
The damping device 9 can be made in different ways. FIG. 7 shows a variation in which an elastic bushing 91 is provided between a disk 26 which is in contact with the part 27 of the machine frame supporting shaft 201 of switch-over lever 20 and switch-over lever 20. Threads 200 are located on the end of shaft 201 away from part 27, a nut 92 and a counter-nut 920 being screwed onto these threads. Between the switch-over lever 20 and a disk 930 on the one hand, and the two nuts 92 and 920 and a disk 931 on the other hand, a pressure spring 93 snaps in. Depending upon the tension of pressure spring 93, preset by nut 92 and counter-nut 920, the switch-over lever 20 is pressed with more or less force against the elastic bushing 91, so that the damping effect of the damping device 9 can be set by presetting the tension.
FIG. 5 shows a further variation of a damping device 9 for the switch-over lever 20. In this embodiment, a piston 94 is connected to the switch-over lever 20 via a piston rod 940, said piston separating two chambers, 950 and 951, from each other within a cylinder. These two chambers 950 and 951 are connected to each other through a throttle line 96 in which a throttle valve 960 is built in, as shown in the example. Cylinder 95 as well as throttle line 96 are filled with a medium which is brought from one chamber 950, into the other chamber 951 (or vice versa) by the piston 94. Due to the narrow cross section of the throttle line 96 and due to the pre-setting of the throttle valve 960, the medium cannot pass easily from one chamber into the other however, and thereby the desired damping effect is achieved.
As the above description shows, the device to drive the machine at different defined speeds can be made in various ways. At the same time, the instant invention is not limited only to the embodiments shown as examples, but the different characteristics can rather be interchanged among each other or through equivalents, or can be used in different combinations. It is therefore absolutely possible to use two pairs of disks and a conventional axial bearing or a conventional direct bearing for the spinning rotor 1, rather than the shown support rollers 11 and combined axial/radial bearing 13.
It is also not necessary to provide two tangential belts (main drive belt 5 and auxiliary drive belt 53) to drive the spinning rotora 1. Here too, a different, appropriate collective drive and/or auxiliary drive can be provided, for example by driving one or more spinning rotors 1 from a main roller via one or more belts attributed to spinning rotors 1, looping with more or less greater force around the shaft 10 of the spinning rotor 1. Neither is it necessary to install the auxiliary drive 57 in the drive framework 500 of the machine. As an alternative it is also possible to install it in the middle between several sections of the machine, or stationary, per section.
The switch-over device 2 also must not necessarily be made in the form of a two-armed switch-over lever 20. Instead of such a two-armed switch-over lever 20, a separate switch-over lever can be provided for the main clamping roller 211 as well as for the auxiliary clamping roller 212, it being only necessary to coordinate their movements with each other in order to obtain the described effect. This can be achieved by electric-pneumatic or electrical means, or by some other means. The same applies also to the brake lever which can be moved by a driving mechanism that is independent of switch-over device 2 but is coordinated with its activation.
Such a device, in which the brake lever 40 is supported independently of the switch-over lever 20, but is moved in coordination therewith, is now explained in FIGS. 8 through 10.
The brake lever 40 is pivotably supported on the one side of shaft 10 on a bearing bolt 41 and extends over and beyond the two supporting discs 11 and shaft 10 of the spinning rotor 1 up to the other side of shaft 10. At this point the tie rod 8 is linked to the free end of the brake lever 40 by means of a bolt 42. Bolt 42 reaches beyond arm 231 of the two-armed switch-over lever 20 on its side away from shaft 10 of spinning rotor 1, said side being configured as a bumper surface 233. Bolt 42 of the brake lever 40, in turn, is configured as a bumper which can be brought into contact with this bumper surface 233 of the switchover lever 20.
As schematically shown, the control lever 82 is a two-armed lever in this embodiment, provided with a roller 823 on its end towards lever 81, said roller being held by the fork 812 of lever 81. The position of tie rod 8 must thus be controlled in function of the position of the control lever 82.
In spinning position, where the control lever 82 assumes its position I (see FIG. 6) the brake lever 40 and the switch-over lever 20 assume the position shown in FIG. 9. At the same time the switch-over lever 20, due to the force exerted by pull spring 220, is held with its bumper surface 233 in contact against bolt 42 of the brake lever 40. In this position of switch-over lever 20 the main clamping roller 211 presses the main drive belt 5 against shaft 10 of spinning rotor 1 while the auxiliary clamping roller 212 releases the auxiliary drive belt 53 which is lifted away from shaft 10 through the action of the supporting discs 50 and 51. For stopping of spinning rotor 1, control lever 82 may be moved independently of a movement of cover 7 (see FIG. 6) or together with the latter in the direction of arrow 83 (FIG. 10). Tie rod 8 therefore is drawn downwardly (as shown by the Figures themselves) and brings brake lever 40 with brake lining 441 to bear against shaft 10 of spinning rotor 1. At the same time the spinning rotor 1 is stopped. Furthermore, when this movement takes place, the tie rod 8 brings the carrier of brake lever 40, in the form of bolt 42, to bear against the bumper surface 233 of the switch-over lever 20 and finally takes said switch-over lever 20 along with it. The main clamping roller 211 thus releases the main drive belt 5 so that the latter is lifted from the shaft 10 by the two supporting discs 50 and 51 and is thus no longer driven.
FIGS. 8 through 10 show that through bearing support of the brake lever 40, independently of the switch-over lever 20, the brake lining 441 and the bearing bolt 41 can be spaced relatively far apart. Therefore the braking movement of the brake lining 441 during braking is nearly linear in the area of shaft 10 of spinning rotor 1, and this linear movement towards shaft 10 does not change greatly even after much wear so that, independently of the degree of brake lining wear, there is no danger for the brake lever 40 to get stuck on shaft 10.
When the maintenance operation for which spinning rotor 1 was shut down is completed, thread joining takes place. In coordination with the other phases of the thread joining process the control lever 82 is moved in direction of arrow 84 after closing of the cover 7 and is brought into position III (FIG. 8). The tie rod 8 is thus lifted, so that the bolt 42 releases arm 231 of the switch-over lever 20. During this lifting movement of the tie rod 8 the brake lever 40 is also pivoted around its axis 41. At the same time the carrier 440 comes to bear against bumper 232 of the switch-over lever 20. The latter is thereby pivoted so that the main clamping roller 211 is lifted away from the main drive belt 5 and the auxiliary clamping roller 212 is pressed against the auxiliary drive belt 53. Through this action the auxiliary drive belt 53 is brought to bear against shaft 10 of the spinning rotor 1 which is thus driven by this auxiliary drive belt 53; the main drive belt 5, released by main clamping roller 211 has been lifted away from shaft 10 by the supporting discs 50 and 51.
In the embodiment described in FIGS. 8 through 10, the brake lever thus serves to selectively pivot the switch-over lever 20 into one or the other pivoting directions in order to brake the spinning rotor 1 in this manner or to drive it at a predetermined thread joining speed, different from production speed. Also, upon completion of the thread joining operation, the spinning rotor 1 can be brought more or less rapidly and in a controlled manner up to production speed before the drive of spinning rotor 1 is again transferred to the main drive belt 5.
FIG. 11 shows a further variation of an open-end spinning station. In this embodiment a pair of friction rollers 12 are used as spinning element, instead of a spinning rotor. Each of the friction rollers 12 (only one roller being visible in FIG. 11) is equipped with a wharve 120 against which either main drive belt 5 or auxiliary drive belt 53 can be brought to bear. For this purpose each of the two belts 5 and 53 is provided with a fork (not shown). Each fork is controllably connected to a separate drive, e.g. a solenoid 52 or 520, whereby the two solenoids 52 and 520 are controlled in coordination with each other from control device 641 on the service unit 64. Thus for example, the fork (not shown) moved by solenoid 52, and tipped with rollers to reduce friction between itself and belt 5, can bring the main drive belt 5 to bear against wharve 120 when solenoid 52 drops off. When solenoid 52 is excited is excited wharve 120 is released by belt 5. In the same way, the solenoid 520 can bring the auxiliary drive belt 53 to bear against wharve 120 when excited and lift auxiliary drive belt 53 away from the wharve when it drops off. If solenoid 52 is excited and solenoid 520 drops off, wharve 120 is not driven at all.
As described in the context of FIGS. 2 and 3 the auxiliary drive belt 53 can again be driven at a speed which is lower than the speed of main drive belt 5 and can then be accelerated up to the speed of main drive belt 5 so that a smooth transfer of the drive to the main drive belt 5 can be ensured. It is however also possible to reverse the direction of the auxiliary drive belt 53 from the service unit 64 as a function of a thread joining program, for instance if this is desirable for the cleaning of the friction rollers 12. The drives of friction rollers 12 of other spinning stations remain unaffected however, so that these rollers continue to be driven by main drive belt 5 at production speed at such other stations. FIG. 11 shows that the fiber material 71 is conveyed by a fiber feeding device 72 and an opening roller 73 to the friction rollers 12. The fiber feeding device 72 is equipped with a feeding roller 720 which sits at one end of a feeding shaft 721. The feeding shaft 721 is connected by a coupling 75 to a feeding shaft 722 equipped with a worm wheel 723 which in turn engages an endless screw 740 located on a main drive shaft 74, part of the collective drive 56, said endless screw rotating together with said shaft.
Between feeding roller 720 and coupling 75 the feeding shaft 721 is provided with a gear 724 which is drivingly connected via a chain 725 with a gear 760. Gear 760 sits at the end of an intermediary shaft 76, connected via a coupling 750 to another intermediate shaft 761 which is equipped with a worm wheel 762 at its free end and is driven by an auxiliary drive shaft 77 (auxiliary drive 57) via an endless screw 77.
By controlling couplings 75 and 750 appropriately, the feed roller 720 can be driven by either the main drive shaft 74 or by the auxiliary drive shaft 77 or by neither of these two shafts 74 and 77, as selected. If desired, the feed roller 720 can also be rotated by the auxiliary drive 77 counter to the feeding direction in order to take the fiber tuft out of range of the opening roller 73. This reversal of the sense of rotation may be initiated by the usual thread monitor (not shown), or by means of service unit 64.
After thread joining the auxiliary drive shaft 77 can be accelerated to the production speed predetermined by the main drive shaft 74, in synchronization with bobbin 70 and/or with the friction rollers 12, whereupon simultaneous activation of couplings 75 and 750 transfers the drive from the auxiliary drive shaft 77 to the main drive shaft 74. It is obvious that such control of the feeding roller can also be applied in connection with a spinning element in the form of a spinning rotor 1 (see FIGS. 1 through 10). | In an open-end spinning machine, a centralized main drive is provided to collectively drive spinning elements of a plurality of spinning stations installed next to each other. At each spinning station, a switch-over device is provided for switching each spinning station over to a stationary, centralized auxiliary drive. The main drive includes a main drive belt to collectively drive the plurality of spinning elements. An auxiliary drive belt driven at a second speed for selectively driving individual spinning units is powered by the stationary centralized auxiliary drive. Using its respective switch-over device, either the main drive belt or the auxiliary drive belt can be selected to drive a given spinning unit. Thread joining preferably takes place at a spinning unit (e.g. spinning rotor) speed relatively close to the production speed of the spinning unit so that strong thread joins and consistent thread results. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to gate and storage dielectrics of integrated circuit devices. More particularly, this invention relates to scalable gate and storage dielectric systems.
A dielectric is an insulating material capable of storing electric charge and associated energy by means of a shift in the relative positions of internally bound positive and negative charges known as charge dipoles. This shift is brought about by an external electric field. A dielectric system is a collaborating arrangement of materials including at least one dielectric material.
Dielectric systems are directly involved in the progress of microelectronic process technology. Successes in the manufacture of quality dielectric systems have done much to advance integrated circuit technology. Improved dielectric systems have traditionally resulted in significant increases in electronic device and system capabilities.
The quality of a dielectric system can be determined generally by a well-defined criteria. One criterion is the effective dielectric constant K of the system. The effective dielectric constant is dependent on the individual dielectric constants of the materials used in the system. A dielectric constant indicates the relative capacity, as compared to a vacuum where K=1, of the material to store charge. Thus, high dielectric constant materials advantageously produce dielectric systems with high capacity to store charge.
Another criterion is the scalability of the system. Scalability of a dielectric system refers to its physical size (i.e., its thickness, measured in nanometers, and area). In particular, the ability to minimize the size of the system is important. Note that a system's thickness and area can each be scaled independently of the other. A dielectric system having a geometrically scalable thickness may allow higher charge storage capacity. A dielectric system having a geometrically scalable area may allow more transistors to be fabricated on a single integrated circuit chip, thus allowing increased functionality of that chip.
Additional criteria for determining the quality of a dielectric system are dielectric interface compatibility and high temperature structural stability. In order to produce a stable and reliable device, a dielectric must be chemically compatible with the semiconductor substrate or plate material with which the dielectric forms an interface. The substrate or plate material is usually silicon. In addition, the substrate and dielectric interface must remain stable over a range of temperatures.
Other criteria are a dielectric system's ability to provide charge control and stoichiometric reproducibility at a substrate/dielectric or plate/dielectric interface. Uncontrollable bonding at an interface may decrease device reliability and cause inconsistent device characteristics from one device to another. Dangling atoms (i.e., atoms that have not formed bonds) from the dielectric material may contribute to an undesirable charge accumulation at the interface. Charge accumulation varying from device to device can lead to an undesirably varying threshold voltage from device to device. The threshold voltage can be defined as the minimum voltage applied to a gate electrode of a device that places the device in active mode of operation.
In addition, leakage characteristics of a dielectric material are particularly important when the dielectric material is used in scaled down devices. A thin gate dielectric often gives rise to an undesirable tunneling current between a gate and the substrate. Tunneling current results in wasted power and is particularly destructive in memory circuitry, in which capacitors coupled to a gate dielectric system may be undesirably discharged by the tunneling (i.e., leakage) current.
High temperature chemical passivity is also an important criterion of a dielectric system. A gate dopant may undesirably diffuse through a gate dielectric material during high temperature device fabrication, corrupting the substrate/dielectric or plate/dielectric interface. The dopant may form bonds with the dielectric material and the substrate or plate material causing an undesirable negative charge buildup at the interface. This negative charge may also result in an undesirable increase in the threshold voltage of the device.
Further, the quality of a dielectric system is also determined by its breakdown characteristics. A uniform dielectric breakdown characteristic across multiple dielectric systems is advantageous because breakdown of a single dielectric system in a device or circuit can cause undesirable and unpredictable device or circuit operation. Loosely defined, a dielectric breakdown occurs when a voltage applied to a dielectric system exceeds a breakdown voltage limit of the dielectric material as it is arranged in the system. Moreover, the breakdown of a storage dielectric can cause stored charge to undesirably dissipate. Thus, a uniform dielectric breakdown characteristic increases system functionality, reliability, and robustness.
Finally, the quality of a dielectric system is further determined by its ability to permit etch selectivity during fabrication. Etch selectivity refers to an ability to selectively remove material to leave behind a desired pattern. The desired pattern corresponds to the arrangement of materials in a system or device. A material that is not significantly etch selective may pose problems in the fabrication of that system or device, as the material may not permit structural integration with other materials of the device.
In an ongoing effort to develop improved dielectric systems, diligent research and experimentation have highlighted problematic dielectric system characteristics. Known limitations of traditional dielectric material silicon dioxide (SiO 2 ), namely its low K value, high leakage characteristic resulting from increased scaling, and its high temperature chemical impassivity, show the need for improved dielectric materials and systems. Attempts to find improved dielectric materials and systems, as defined by the criteria described above, have had limited success. Particularly, attempts to develop a dielectric system that concurrently satisfies all of the above concerns and issues and that overcomes the limitations of SiO 2 have been unsuccessful.
In view of the foregoing, it would be desirable to provide improved dielectric systems.
It would also be desirable to provide methods of fabricating improved dielectric systems.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide improved dielectric systems.
It is also an object of the present invention to provide methods of fabricating improved dielectric systems.
Gate and storage dielectric systems of the present invention provide high effective K values. Improved gate and storage dielectric stacks include a high K dielectric material that produces improved device characteristics such as increased storage capacity and increased drive current. Additionally, the improved dielectric stacks include a passivated overlayer that maintains the high effective K values, is in addition to other desirable characteristics. For example, a silicon-rich-nitride passivated overlayer advantageously provides a stoichiometric interface between a dielectric and a substrate or storage plate. In addition, a silicon-rich-nitride passivated overlayer advantageously provides charge control and regulation of threshold voltage in metal-oxide-semiconductor field effect transistors (MOSFETs).
Methods of fabricating improved gate and storage dielectric systems are also provided by the present invention. A substrate or bottom storage plate is carefully prepared before subsequent deposition of metal or, in other embodiments, dielectric material. Metal or dielectric materials are deposited to minimize thickness and to maximize storage capacity. Increased storage capacity, which is also characteristic of high K materials, increases area scaling capabilities. Increased area scaling can reduce the integrated circuit chip area required to fabricate an integrated circuit device. Thus, either more devices can be fabricated on a single integrated circuit chip, advantageously allowing increased functionality, or more integrated circuit chips can be fabricated on a single wafer, advantageously reducing costs.
The passivated overlayer is deposited such that the resulting K value of the overlayer does not compromise the high K value of the dielectric used in the dielectric stack. Dielectric stacks may be appropriately annealed to provide greater stack stability.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages of the invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:
FIG. 1 is a cross-sectional diagram of an exemplary embodiment of a gate dielectric stack according to the invention;
FIG. 2 is a cross-sectional diagram of a known gate dielectric stack;
FIG. 3 is a graph of dielectric constants versus refractive indices of silicon-rich-nitride;
FIG. 4 is a cross-sectional diagram of an exemplary embodiment of a storage dielectric stack according to the invention;
FIGS. 5 and 6 are cross-sectional diagrams of improved integrated circuit devices using the dielectric stacks of the invention;
FIG. 7 is a flowchart of an exemplary embodiment of a method of fabricating a dielectric stack according to the invention;
FIG. 8 is a graph of refractive indices of silicon-rich-nitride versus ratios of dichlorosilane-to-ammonia used in the fabrication of silicon-rich-nitride; and
FIG. 9 is a flowchart of another exemplary embodiment of a method of fabricating a dielectric stack according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides improved dielectric systems and methods of their fabrication in which many quality concerns and issues of dielectric systems are preferably concurrently satisfied.
FIG. 1 shows a gate dielectric stack 100 in accordance with the invention. Stack 100 includes substrate 102 , gate dielectric 104 , passivated overlayer 106 , gate 108 , and gate electrode 110 . Substrate 102 can be one or more semiconductor layers or structures which can include active or operable portions of semiconductor devices. Generally, substrate 102 comprises silicon (Si). Gate 108 can comprise a degenerate heavily doped polysilicon, a metal, or other conductive material.
Gate dielectric 104 , which can also be referred to as gate insulator 104 , includes a single phase stoichiometrically-uniform-composition material having a high dielectric constant (e.g., K≧10) or a silicon or transition-metal doped derivative thereof. A single phase stoichiometrically uniform material includes a single material having a consistently precise number of atoms and bonds in a molecule of the material. A transition metal dopant of gate dielectric 104 may be zirconium, tungsten, hafnium, titanium, tantalum, or other suitable transition metal. In particular, gate dielectric 104 is preferably stoichiometric alumina (Al 2 O 3 ), which has a K value in the range of about 11 to about 12. Alumina is oxidized aluminum, a metal which can be deposited one atomic layer at a time to form ultra thin metal films (e.g., less than about 3 nm). These metal films are subsequently oxidized in ultra pure oxygen or ozone plasma to produce stoichiometric alumina. Alternatively, gate dielectric 104 can be a composite such as silicon-doped alumina or transition-metal-doped alumina, each typically having a K>15.
A high K dielectric permits greater scalability of a dielectric stack. Scalability of a dielectric stack refers to the ability to reduce the size of the stack. Smaller dielectric stacks preferably allow, among other things, more transistors to be fabricated on an integrated circuit chip, thus allowing more functionality on that chip. Greater scalability of the area occupied by the stack is possible because a high K gate dielectric has a higher dielectric capacitance per unit area (C d ) for a fixed dielectric thickness (t d ) than a lower K dielectric material, such as traditionally used silicon dioxide (K≈4). This is shown in the relationship C d ∝K/t d . A higher dielectric capacitance per unit area corresponds to a higher capacity to store charge, which can compensate for the storage capacity characteristically lost when the area of a dielectric device or system is scaled.
Moreover, because drive current is directly proportional to dielectric capacitance in metal-oxide-semiconductor field effect transistors (MOSFETs), the increased dielectric capacitance per unit area provided by a high K dielectric provides increased drive current. Drive current can be generally defined as the current flowing through induced channel 118 from drain electrode 120 to source electrode 122 when, in the presence of sufficient potential between drain electrode 120 and source electrode 122 , a voltage equal to or greater than the threshold voltage of the MOSFET device is applied to the gate. A low K dielectric material in gate dielectric 104 may not provide sufficient drive current, even when the thickness of gate dielectric 104 is scaled. Thus, to provide sufficient drive current, a high K dielectric is often required.
The scalability of high K gate dielectric 104 is but one consideration when evaluating the quality of a dielectric system. Because gate dielectric 104 forms interface 112 with substrate 102 , the gate dielectric material should also be chemically compatible with the substrate material.
Alumina, when used as gate dielectric 104 , is chemically compatible with a silicon substrate 102 . However, the combination of the two materials does not inherently provide a stoichiometric interface at interface 112 . During device fabrication, hydroxide ions can cause undesirable and nonstoichiometric formation of alumino-silicate (Al x Si y O z ) at interface 112 . The hydroxide ions may be absorbed into a silicon substrate or plate in the form of Si x O y H z and may be naturally present due to exposure of the substrate or plate to open air or to ambient hydroxide. Alumino-silicate formed at interface 112 can have an undesirably lower K value than the stoichiometric alumina gate dielectric, producing an undesirably lower effective K value for the dielectric stack. Moreover, known fabrication methods may result in uncontrollable and incomplete alumino-silicate bonding at interface 112 .
Incomplete bonding at interface 112 can cause an undesirable accumulation of fixed negative charge at interface 112 . This may result in an undesirable increase in the threshold voltage of the device. In particular, dangling atoms from the dielectric material of gate dielectric 104 (i.e., atoms that have not formed bonds) and from substrate 102 may contribute to the undesirable fixed interface charge accumulation at interface 112 .
Passivated overlayer 106 advantageously prevents dopant used in gate 108 from readily diffusing through high K gate dielectric 104 to form bonds at interface 112 . This dopant diffusion phenomenon may be especially evident at high temperatures common during device fabrication. For example, as shown in FIG. 2, the combination of a phosphorus-doped silicon gate 208 deposited directly upon alumina gate dielectric 204 causes the formation of an alumino-phospho-silicate layer 203 at interface 212 . Interface 212 may have originally been less of an uncorrupted interface between gate dielectric 204 and silicon substrate 202 before high temperature fabrication caused phosphorous dopant diffusion through gate dielectric 204 .
Alumino-phospho-silicate layer 203 may contribute to negative charge buildup (Q I ) at interface 212 . The known device of FIG. 2 generally has a fixed Q I ≈3e+13 (i.e., Q I ≈3×10 13 ) fundamental charge units per cm 2 . One fundamental charge unit is equal to about 1.60218e−19 coulombs. As described above, a fixed charge accumulation in the dielectric material undesirably causes an increase in the threshold voltage. Because dopant diffusion through gate dielectric 204 may be uncontrollable, formation of alumino-phospho-silicate layer 203 may be uncontrollable. Consequently, the negative charge at interface 212 , and the threshold voltage of any device that uses this known stack, may be uncontrollable and may undesirably vary from device to device.
Alumino-phospho-silicate layer 203 may also have a lower K value than that of gate dielectric 204 . This causes an undesirable lowering of the effective K value of the dielectric stack. Again, this would adversely affect at least one of the advantages of having a high K value, namely scalability.
Returning to FIG. 1, passivated overlayer 106 forms chemically inert interface 114 with gate 108 and forms chemically inert interface 116 with gate dielectric 104 . A chemically inert interface is an interface at which no substantial bonding occurs between the materials forming the interface.
Passivated overlayer 106 preferably provides high temperature chemical passivity in dielectric stack 100 . In particular, passivated overlayer 106 prevents diffusion of dopant from gate 108 through gate dielectric 104 , which would subsequently corrupt interface 112 and lower the effective K value of the stack. Passivated overlayer 106 thus prevents additional fixed charge formation. Consequently, the combination of the contaminant protection of passivated overlayer 106 and the stoichiometry of interface 112 provides a reduced interface charge in the device of FIG. 1 . Stack 100 advantageously has a fixed Q I approximately ≦3e+10 fundamental charge units per cm 2 , which is significantly less than the typical fixed interface charge of known devices of Q I ≈3e+13 fundamental charge units per cm 2 .
In addition, passivated overlayer 106 preferably provides uniformity in the dielectric breakdown voltage limit of the dielectric stack. The contaminant protection provided by passivated overlayer 106 prevents local (i.e., geometrically small) defects in gate dielectric 104 that contribute to a lower dielectric breakdown voltage. Moreover, in the absence of passivated overlayer 106 , uncontrollable dopant diffusion into gate dielectric 104 may likely result in an undesirably uncontrollable and varying threshold voltage.
Further, passivated overlayer 106 preferably provides uniform injection of either electrons or holes from gate 108 into gate dielectric 104 when a voltage is applied to gate electrode 110 . The injection of electrons or holes corresponds respectively to either an n-type or p-type gate 108 . Passivated overlayer 106 thus improves reliability and uniformity in gate dielectric stack 100 .
Passivated overlayer 106 is preferably “injector” silicon-rich-nitride (SRN), which is an SRN with a refractive index of about 2.5 or greater, and preferably has a thickness in the range of about 0.5 to about 3.0 nm. Injector SRN can be characterized as a two phase insulator consisting of uniformly distributed silicon nano crystals in a body of stoichiometric nitride. A refractive index of about 2.5 or greater provides passivated overlayer 106 with a dielectric constant comparable to or greater than that of a high K gate dielectric 104 . Particularly, injector SRN has a dielectric constant that is greater than or equal to 12, which is the K value of silicon. Thus, the benefits of a high K gate dielectric 104 , as described above, are not canceled by the addition of passivated overlayer 106 . Alternatively, passivated overlayer 106 can be an SRN with a refractive index of less than about 2.5; however, a maximum K and the benefits associated therewith in a dielectric stack are achieved when the refractive index is greater than about 2.5.
FIG. 3 illustrates the relationship between the refractive indices and dielectric constants K of injector SRN. As shown, injector SRN with a refractive index of about 2.5 or greater provides a K value greater than about 12, which is the dielectric constant of silicon.
FIG. 4 shows a storage dielectric stack 400 in accordance with the invention. Stack 400 includes bottom plate 402 , storage dielectric 404 , passivated overlayer 406 , and top plate 408 . Bottom plate 402 and top plate 408 can be a degenerate heavily doped silicon, a doped polysilicon material, a metal, or other conductive material.
Storage dielectric 404 is preferably the same material as that of gate dielectric 104 , namely alumina or a doped derivative of alumina. As previously described, alumina is oxidized aluminum, a metal which can be deposited in ultra thin metal films (e.g., less than about 3 nm) and subsequently oxidized in ultra pure oxygen or ozone plasma to produce stoichiometric alumina. A high K dielectric value (e.g., K≧10) in storage dielectric 404 provides a higher storage capacity, which is advantageous in memory devices such as DRAMs (dynamic random access memories). High storage capacity in high K dielectrics results from the high capacitance per unit area provided by high K dielectrics, as previously described.
Passivated overlayer 406 is preferably the same material as that of passivated overlayer 106 , namely injector SRN or SRN, and preferably serves the same or similar purposes in the stack. In particular, passivated overlayer 406 prevents diffusion of dopant from top plate 408 through storage dielectric 404 . Passivated overlayer 406 provides uniform injection of electrons or holes from top plate 408 into storage dielectric 404 during voltage stress and provides uniform dielectric breakdown in storage dielectric 404 . Passivated overlayer 406 preferably has the same range of thickness (i.e., about 0.5 to about 3 nm) and refractive index (i.e., ≧about 2.5) as passivated overlayer 106 . The fixed charge (Q I ) at interface 412 is advantageously about the same as in gate dielectric stack 100 , namely Q I approximately ≦3e+10 units of fundamental charge per cm 2 .
FIG. 5 shows an integrated circuit device 500 using the dielectric stacks of the invention. Device 500 is an embodiment of a deep trench storage capacitor DRAM cell that includes embodiments of the gate and storage dielectric stacks of the invention. Storage (capacitor) dielectric stack 501 includes bottom plate/substrate 502 , storage dielectric 504 , passivated overlayer 506 , and top plate 508 . A logic data bit is written into storage dielectric stack 501 via bit line 510 when sufficient voltage is applied to bit line 510 and the voltage at word line 512 (i.e., at the gate electrode) rises above the threshold voltage of gate dielectric stack 100 . Conversely, a logic data bit is read from storage dielectric stack 501 via bit line 510 when insufficient voltage is applied to bit line 510 and the voltage at word line 512 rises above the threshold voltage of gate dielectric stack 100 . Oxide 514 , oxide 516 , and oxide 518 isolate storage dielectric stack 501 . Improved device characteristics of device 500 are obtained from gate dielectric stack 100 and storage dielectric stack 501 . For example, stoichiometric interface 112 provides a desirable lower threshold voltage for performing both read and write operations. Also, the improved charge storage capacity of storage dielectric stack 501 enhances memory capacity and reliability.
Similarly, FIG. 6 shows another embodiment of an improved DRAM capacitor device using the dielectric stacks of the invention. Device 600 is a stacked capacitor DRAM cell that includes gate dielectric stack 100 and storage (capacitor) dielectric stack 601 in accordance with the invention. Storage dielectric stack 601 includes bottom plate 602 , storage dielectric 604 , passivated overlayer 606 , and top plate 608 . Operation of device 600 is similar to that of device 500 . A logic data bit is written into storage dielectric stack 601 via bit line 610 when sufficient voltage is applied to bit line 610 and the voltage at word line 612 (i.e., at the gate electrode) rises above the threshold voltage of gate dielectric stack 100 . Conversely, a logic data bit is read from storage dielectric stack 601 via bit line 610 when insufficient voltage is applied at bit line 610 and the voltage at word line 612 rises above the threshold voltage of gate dielectric stack 100 . Current flows through electrical contact 614 as storage dielectric stack 601 charges and discharges. The improved characteristics of device 600 are similar to those of device 500 and are similarly obtained from the dielectric stacks of the invention.
The gate and storage dielectric stacks of FIGS. 1 and 4 - 6 can be fabricated by the method shown in FIG. 7 in accordance with the invention. Process 700 begins at 702 by first preparing the silicon substrate or silicon bottom plate of a dielectric stack. Native radical hydroxide ions (OH − ) are removed from at least a portion of the surface of, for example, silicon substrate 102 or silicon bottom plate 402 . Hydroxide ions may be present in bonds of silicon and silicon hydroxide (Si x O y H z ) that can form naturally in silicon exposed to open air or to ambient hydroxide. If not removed, these radical hydroxide ions may react with a metal-derived gate dielectric material and substrate material, or a metal-derived storage dielectric material and bottom plate material, to form nonstoichiometric bonding. For example, radical hydroxide ions may react with aluminum and silicon to form a nonstoichiometric Al x Si y O z material. The removal of OH − involves controllably introducing a hydrofluoric acid (HF) vapor in an ultra pure nitrogen bleed-in, while maintaining sufficient vacuum. Generally, a vacuum of approximately less than about 10 −6 torr is sufficient and can be maintained in a high vacuum chamber.
Next, at 704 , a single atomic layer of a metal is deposited on the prepared substrate or bottom plate. The metal is preferably aluminum, subsequently oxidized using a controlled amount of ultra pure oxygen or ozone plasma to form stoichiometric alumina at step 706 . Oxidation may be followed by an appropriate anneal (not shown) to stabilize the dielectric stack. Steps 704 and 706 are preferably repeated until a desired thickness of alumina is obtained. Aluminum may be deposited by atomic layer deposition (“ALD”), molecular bean epitaxy (“MBE”), electron beam evaporation, sputtering, or any other suitable method. This procedure should be performed in a vacuum or in a high partial pressure of dry nitrogen gas (N 2 ) to ensure that no undesirable OH − ions are in the environment.
Next, at 708 , a passivated overlayer is deposited on the dielectric material. The passivated overlayer is preferably silicon-rich-nitride (SRN) and is preferably deposited in a layer ranging from about 0.5 to about 3.0 nm in thickness. The SRN preferably has a refractive index of ≧2.5. Passivated overlayer deposition can be accomplished by a low pressure plasma enhanced chemical vapor deposition process with silane (SiH 4 ) or dichlorosilane (SiH 2 Cl 2 ), ammonia (NH 3 ), and nitrogen such that the ratio of SiH 4 to NH 3 , or SiH 2 Cl 2 to NH 3 , is approximately ≧15. This ratio regulates the amount and distribution of each phase of the silicon-rich-nitride, namely the amount and distribution of the silicon nitride insulator (Si 3 N 4 ) and either crystalline or amorphous silicon (Si) particles. The ratio of SiH 2 Cl 2 to NH 3 has been found to be directly proportional to the refractive index of the resulting SRN material, as shown in FIG. 8 . Thus, control of the SiH 2 Cl 2 /NH 3 ratio is important. For example, a SiH 2 Cl 2 /NH 3 ratio of 15 produces a SRN material with a refractive index of approximately 2.5, a value that ensures a K>12. As noted previously, a deposited SRN material should preferably have a K value similar to that of the high K dielectric material, such that the advantages of the high K dielectric material are not canceled out by a passivated overlayer with a low K value.
Returning to FIG. 7, the dielectric stack may then be stabilized by a rapid thermal anneal in nitrogen at 710 . A gate and gate electrode, or top plate, are deposited at 712 , depending on whether a gate dielectric stack or a storage dielectric stack is being fabricated.
If a storage capacitor is being fabricated, step 708 can be optionally eliminated. That is, a passivated overlayer may not need to be included in a storage dielectric stack fabricated in accordance with the invention. Process 700 without 708 may be sufficient to achieve an improved storage capacitor stack. However, a passivated overlayer in a storage dielectric stack provides a preferably maximum achievable K value and consequently higher storage capacity.
In another embodiment of a method to fabricate dielectric stacks in accordance with the invention, 704 involves depositing metal to a desired thickness and then subsequently oxidizing the entire thickness in a controlled manner to form the desired stoichiometric dielectric material. For example, aluminum may first be deposited to the desired thickness and then oxidized to form stoichiometric alumina.
FIG. 9 shows yet another embodiment of a method to fabricate improved dielectric stacks in accordance with the invention. In process 900 , 704 and 706 of process 700 are replaced by 902 . At 902 , a dielectric material is deposited directly on a prepared substrate or bottom plate. The dielectric material if preferably alumina and may be deposited by MBE, sputtering, or any other suitable method.
Thus it is seen that improved gate and storage dielectric systems, and methods of their fabrication, are provided. One skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which are presented for purposes of illustration and not of limitation, and the present invention is limited only by the claims which follow. | Gate and storage dielectric systems and methods of their fabrication are presented. A passivated overlayer deposited between a layer of dielectric material and a gate or first storage plate maintains a high K (dielectric constant) value of the dielectric material. The high K dielectric material forms an improved interface with a substrate or second plate. This improves dielectric system reliability and uniformity and permits greater scalability, dielectric interface compatibility, structural stability, charge control, and stoichiometric reproducibility. Furthermore, etch selectivity, low leakage current, uniform dielectric breakdown, and improved high temperature chemical passivity also result. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to provisional application No. 61/575,110 filed on Aug. 16, 2011.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
The present invention relates to watercraft and specifically to a catamaran-style, recreational watercraft with an adjustable beam.
Canoeing, kayaking, rowing and sailing have long been popular water sports. As healthy, environmentally clean avenues for recreation, their appeal should continue to grow.
Each of the aforementioned water sports employs its own specialized boat-form, so that with new boating interests or changes in boating conditions an individual might need to acquire new craft, increasing financial burden and creating issues related to storage.
Since one of the main factors impacting watercraft performance is the ratio of width or beam to length, a boat constructed to have a variable beam could potentially serve multiple functions and be made to suit a variety of boating conditions. The most straightforward means for creating an adjustable beam is to modify a traditional catamaran-form, so as to allow for the spacing between pontoons or hulls to be deliberately altered by an operator.
There have been many proposed and realized examples of multihulled vessels with adjustable beams. In the majority of cases the inventor's goal has been to enjoy the stability of wide, multihulled craft, while meeting width restrictions related to trailering the boats on roads and highways.
The adjustable beam craft described in U.S. Pat. No. 2,992,444, U.S. Pat. No. 4,909,169, U.S. Pat. No. 6,003,458, U.S. Pat. No. 6,874,440, U.S. Pat. No. 7,628,115, B2, U.S. Pat. No. 6,546,885 B1, U.S. Pat. No. 3,981,259, U.S. Pat. No. 5,651,706, and U.S. Pat. No. 4,172,426 were drawn toward allowing trailering and reducing storage space requirements. In each of these cases, the watercraft's narrowest configuration was not considered as an operative condition. Further, the apparatuses employed are relatively complex and likely demand mechanical aid in generating the required force to reposition hulls.
Since the desire to reduce boat width has mostly related to transport, little consideration has been given to a narrow or retracted configuration as a functional state.
The design recorded under U.S. Patent 2007/0028830 A1 is one exception. Here the last section of the stern of the craft is bisected forming two small self-contained hull sections separate from the main hull. The small sections are hinged to the larger section in such a way as to allow them to pivot outward, effectively expanding the beam, hence, adding to the stability of the craft. The design is meant to allow for effective paddling from a seated position when the smaller hulls are retracted and fishing from a standing position when expanded.
One drawback of this design is that the relatively small size of the pivoting hulls limits the stability offered. Also problematic, is the complexity of the pivoting mechanism, which is comprised of an arrangement of cables, pulleys, hinges and levers.
Another invention that seeks to exploit the versatility of a watercraft by varying the beam is described in U.S. patent 2003/0213423 A1. In this design, two hull segments may be joined together into one or configured as a two-hulled catamaran using a collapsible frame to separate the hull sections. This craft provides multiple uses and propulsion options, but requires that the operator assemble and disassemble components in order to achieve the desired adjustments.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention is to provide a recreational watercraft, with functional versatility, afforded by a manually adjustable beam.
In a particular embodiment the present invention includes two, decked hulls, connected by two, adjustable-length crossbars and spanned by a rigid platform deck. The construction and arrangement of the aforementioned elements allows the craft's operator to manually adjust, within set limits, the lateral position of each hull relative to the longitudinal centerline of the platform deck.
The operation of laterally positioning the hulls is made possible by adjustable-length crossbars. An obvious method for constructing adjustable crossbars might be to employ a telescoping arrangement whereby a crossbar segment, connected to one pontoon, slides inside of a larger diameter crossbar segment, attached to the opposite pontoon. In the present invention, however, the limited reach of the telescoping members relative to the performance requirements and necessary structural integrity would not be great enough. Also, the frictional force associated with telescoping members, as described above, would be difficult to overcome.
In the present invention, adjustable crossbars are each configured from pairs of rigid members or bar segments fed through specialized pieces of hardware, henceforth referred to in this document as “slide blocks.” The slide blocks are mounted securely to the underside of the platform deck, centered on the longitudinal centerline with one positioned near the bow end and the other near the stern. The slide blocks are fabricated so that each possesses two parallel passages, one for each of the bar segments. The passages are dimensioned so as to allow the bar segments to pass freely but not sloppily through them. Enough space is provided between the passages to allow the bar segments to avoid contact with one another when sliding past. Each bar segment runs through its own passage in the slide block, perpendicular to the hulls and is connected in a fixed manner to one of the hulls at a determined placement.
With the bar segments fed into the slide block passages and the components securely connected, as described above, the relative position of hulls and deck are locked in all directions other than along a transverse line. The pontoons are able to be moved in and out.
Handles, located near the transverse center line on the top, outer edge of each hull, provide points upon which the operator may apply force toward retracting and expanding the lateral positions of the hulls.
The merits of the present invention lie in its versatility and simplicity of construction. Scaled to accommodate one or two operators, the craft could, in its narrowest configuration, be paddled from a position seated on the platform deck, using a kayak paddle or single-blade paddle. The narrow configuration would also allow the craft to be transported in the bed of most pick-up trucks or secured to a car top. In its widest configuration, the platform deck could be stood upon for fishing or stand-up paddling. Also, in its widest configuration the present invention could accommodate a sail rig, small motor, or pedal-drive.
The apparatus for laterally adjusting pontoons requires a minimum of moving parts and no machine is necessary for generating the force necessary for positioning the hulls. No assembly or disassembly is required in order to adjust hull spacing, although the present invention can be quickly and easily disassembled into three main parts and then, as quickly and easily, reassembled if desired by the operator.
The foregoing provides a broad description of the present invention and its advantages. The accompanying drawings with their descriptions below, along with the detailed description to follow will further explain the assembly of components, operation and novel features of the present invention. The drawings referred to in the following descriptions are intended to be illustrative and not restrictive toward describing the present invention.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a perspective of the present invention in its closed or retracted configuration with an operator shown paddling.
FIG. 2 is a perspective of the present invention in its open or extended configuration with an operator fishing.
FIG. 3 is a plan of the topside of the present invention in its open configuration.
FIG. 4 is an end elevation of the present invention in its open configuration.
FIG. 5 is section detail showing cut laterally at along a line indicated in FIG. 3 .
FIG. 6 is a plan of the topside of the present invention in its closed configuration.
FIG. 7 is an end elevation of the present invention in its closed configuration.
FIG. 8 is a plan of the underside of the present invention in its closed configuration.
FIG. 9 is a plan of the underside of the present invention in its open configuration.
FIG. 10 is a detail of a side elevation of the present invention, focusing on the intersection of the platform deck and hull at the area where the adjustable-length crossbar meets the hull.
FIG. 11 is a side elevation of the present invention.
FIG. 12 is a detail of a perspective showing the area of the adjustable-length crossbar where the bar segments pass through the slide block.
DETAILED DESCRIPTION OF THE INVENTION
As discussed above, embodiments of the present invention relate to watercraft and specifically to a catamaran-style, recreational watercraft with a manually adjustable beam.
Referring to the drawings by numeral, the largest components of the present invention are the two, equal length, decked hulls 1 , which are made from molded plastic or comparable marine-grade hull material.
The catamaran boat-form is realized by connecting the two hulls 1 , port and starboard, so that they remain parallel to one another and aligned so that, if drawn in plan, a line touching both bow tips would be perpendicular to the longitudinal centerline of the craft.
In the present invention, the structural connection between hulls is made by at least two adjustable-length crossbars 3 . Each adjustable-length crossbar 3 is composed of a pair of bar segments 4 and a piece of specialized hardware, referred to in this document as a “slide block” 5 . The bar segments 4 are made from appropriately dimensioned, rigid tubes of aluminum or other corrosion resistant, material with comparable structural properties. Each bar segment 4 is fixed on one end to one of the two pontoons 1, leaving the opposite end unattached or free.
In the present embodiment the connections between bar segments 4 and hulls 1 is made by having the bar segments 4 lie across the deck surfaces of the hulls 1 in a direction perpendicular to the longitudinal centerline and using bolts or similar fasteners to secure the bar segments 4 through the deck surfaces of the hulls 1 . The number and spacing of bolts used, holds the components securely together denying separation and racking. The mounting location of each bar segment 4 to its respective hull 1 is determined by the location of the slide blocks 5 relative to the platform deck 2 and position of the platform deck 2 relative to the hulls 1 . In the present embodiment, the platform deck 2 will be roughly centered between the bow and stern. The slide blocks 5 are bolted or similarly mounted or formed into the underside of the platform deck 2 , centered on the longitudinal centerline of the platform deck 2 , one near the front edge and one near the rear edge.
The slide blocks 5 are fabricated from aluminum or other corrosion resistant, material with comparable structural properties. Each slide block 5 has two parallel passages and each passage is lined with UHMW plastic or material with similar wear properties and low coefficient of friction.
The function of each slide block 5 is to receive the free end of each of a pair of bar segments 4 , one from each hull, and to align the bar segments 4 parallel to one another and to hold them parallel, while, at the same time, allowing the bar segments 4 to slide back and forth along the path dictated by the two passages.
In a given slide block 5 there is one lined passage for each of the bar segments 4 in a pair. The lined passages are spaced enough apart, so as to prevent contact between bar segments 4 as they slide past one another. The lined passages are dimensioned so as to allow bar segments 4 to pass freely but not sloppily through them.
Adjustable-length crossbars 3 are assembled by feeding the free end of a bar segment 4 connected to the port pontoon into one passage in a slide block 5 and feeding the free end of a bar segment 4 from the starboard hull into the other passage.
When all connections are made, as described above, and all bar segments 4 are fed into their respective slide block passages the relative positions of hulls 1 and platform deck 2 are locked in all planes but those intersected by the transverse axis. The hulls 1 are only able to be moved in and out relative to the longitudinal centerline of the platform deck.
Mounting the adjustable-length crossbars 3 to the underside of the platform deck 2 and to the topside of the hulls 1 , dictates that the platform deck 2 will ride above the hulls 1 . To mitigate the tensile and compressive forces acting upon the adjustable crossbars 3 , the weight of the platform deck 2 and all that rests upon it is partially supported by the platform deck 2 itself, resting its longitudinal edges upon transverse ridges 7 formed or built into the deck surfaces of the hulls 1 . The ridges 7 also elevate the deck, providing the necessary clearance to avoid contact and resulting friction between the underside of the platform deck 2 and the bar segments 4 , while the position of the hulls 1 is being adjusted. The points of contact between the ridges 7 and the platform deck 2 will be made from or covered with a material with favorable wear properties and a low coefficient of friction.
When assembled in accordance with the descriptions above, the present embodiment can be configured into a range of widths. In its narrowest configuration, each outer longitudinal edge of the platform deck 2 is approximately flush with the outer edge of the hull 1 of that side, so that the narrowest possible beam of the craft is roughly equal to the width of the platform deck 2 . When the craft is in its widest configuration, the outer edges of the platform deck 2 will overlap the inside edges of each hull's 1 deck surface, by approximately 1 to 3 inches.
Altering the lateral position of a given hull 1 is achieved manually. Each hull has a handle 6 securely mounted near its transverse center line on its top, outer edge. In order to change a hull's 1 lateral position, relative to the platform deck 2 , the operator places his or her hand around the given handle 6 and applies force in the direction of the desired movement. The applied force will cause the bar segments 4 of the given hull 1 to slide in the direction of force through the passages in the stationary slide block 3 while the outer longitudinal edge of that side's platform deck ride across the surfaces of the hull's transverse ridges 7 , thus, adjusting the lateral position of the given hull 1 .
In the present embodiment, when the desired orientation for each hull is achieved their positions can be locked with a simple thread-driven friction brake 8 . The brake works in a fashion similar to a t-bolt used in combination with a jig knob. The knob end of the bolt is located on the top side of the platform deck 2 with the bolt shaft running down through the platform deck 2 , along the edge of a given slide block 3 and between the two bar segments 4 . A flat, horizontal element at the bottom of the bolt shaft is oriented so that turning the knob in a given direction will raise the flat element until it makes contact with the undersides of each bar segment 4 . Tightening the brake 8 will grab and hold the bar segments, thus holding the hulls 1 in their relative positions.
It should be understood that the particular embodiments conveyed in the included drawings and written descriptions are not meant to represent the sole embodiments of the present invention. Those skilled in the art will recognize that modifications may be made, producing variations, which maintain the spirit and novel features of the present invention, and do not fall beyond the scope of the present invention. | A catamaran-style watercraft with a manually adjustable beam. The beam expanded or contracted by an operator applying force in a desired direction to a given hull. Movement is afforded by adjustable-length crossbars, which span and connect each of the two hulls, allowing the hulls to slide beneath the underside of an operator-supporting platform deck. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
The invention disclosed in the present application is related to U.S. Patent Application Ser. No. 696,326 "Ground Fault Protection Device" filed June 15, 1976 by John T. Wilson and assigned to the assignee of the present application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to electrical apparatus, and more particularly, to apparatus for protecting electrical circuits from damage due to ground faults.
2. Description of the Prior Art
In designing circuits for the transmission and distribution of electrical power, it is customary to provide means for protecting the conductors and electrical apparatus being powered from the conductors from overcurrent conditions. It has gradually been recognized that devices employed for overcurrent protection are not sufficient to prevent damage resulting from ground faults; that is, a short circuit between one or more of the electrical conductors and objects connected directly or indirectly to ground. The amount of current which flows through a ground fault may be below the level required to operate the overcurrent protective devices. However, this ground fault current can result in high transient overvoltages throughout the system, high temperatures due to arcing conditions leading to fire, or both.
Various methods of detecting and correcting ground faults have been used in the past. A current transformer is positioned to surround the conductors of the circuit being protected. This transformer, also referred to as a current monitor, produces an output signal upon occurrence of a ground fault condition at a point downstream from the current monitor on the circuit being protected. The monitor is connected to a separate device known as a sensor which includes a switching device such as a relay actuated by the output from the current monitor when a ground fault occurs. The contacts of the relay are then used to interrupt the supply of electrical power to the circuit being protected. A device disclosed in copending U.S. Patent Application Ser. No. 696,326, filed June 15, 1976, by John T. Wilson performs the same function and is self-powered and self-contained in a unitary molded insulating housing. It would be desirable to provide a self-powered self-contained ground fault device which is suitable for use at a variety of ground fault trip current levels.
SUMMARY OF THE INVENTION
In accordance with the principles of the present invention there is provided a self-contained self-powered ground fault protective device having an interchangeable rating plug. The device includes a current monitor, means for actuating associated circuit interrupter devices, switching means connected to the output of the current monitor for triggering the actuating means, and a main housing of molded insulating material supporting and completely enclosing the current monitor, triggering means, and switching means. The main housing includes an aperture, or window, through which the conductors of the circuit being protected are passed and a socket adapted to receive an interchangeable rating plug. When ground fault current above a predetermined level flows through this circuit, the current monitor will produce an output to the triggering means which in turn energizes the switching means and actuates a set of contacts. These contact outputs can be used to control a circuit breaker or other circuit interrupting device to disconnect the source of electrical power to the circuit being protected.
The interchangeable rating plug includes a resistor mounted in an insulating plug housing and connected to male connectors adapted to be inserted into corresponding female connectors in the main housing socket. The rating plug also includes a member adapted to actuate a switch in the triggering means to change the level of grounnd fault current at which the device will trip. A variety of rating plugs, each identical except for the value of the resistor, can be used with a single ground fault protective device to provide for tripping at a variety of ground fault current levels.
The ground fault protective device is powered entirely by the ground fault current flowing through the circuit being protected and requires no physical connection other than to an associated circuit interrupter for deenergizing the circuit being protected. Since the device is entirely self-powered and self-contained, cost and installation requirements are minimized. The use of a variety of interchangeable rating plugs allows a single device to be used to trip at a variety of ground fault current levels.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel and distinctive features of the invention are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may be best understood, however, by reference to the following description and accompanying drawings, in the several figures of which like reference characters identify like elements, and in which:
FIG. 1 is a perspective view of a ground fault protective device incorporating the principles of the present invention;
FIG. 2 is a front elevational view with parts partially cut away of the device shown in FIG. 1;
FIG. 3 is a schematic drawing of the electrical circuitry of the device shown in FIGS. 1 and 2;
FIG. 4 is a front elevational view of the interchangeable rating plug shown in FIGS. 1 and 2; and
FIG. 5 is a side view of the circuit board shown in FIG. 2; and
FIG. 6 is a perspective view of a resilient switch arm having bifurcated ends.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 there is shown a perspective view of a ground fault protective device 10 incorporating the principles of the present invention. The device 10 includes a molded insulating housing 12 comprising a front shell 14 and a rear shell 16 joined by fastening devices such as rivets 18. The housing 12 includes an aperture or window 20 through which the conductors 21 of the electrical circuit being protected are passed. Three terminals 22 are mounted upon the top side of the housing 12 and are protected by a removable cover 24. The terminals 22 are connected to contacts of a bistable switching device such as latching relay 26 shown more clearly in FIG. 2. Also extending through the top of the housing 12 is a reset indicator button 28 mechanically connected to the latching relay 26. To the right of the terminals 22 as seen in FIG. 1, a rating plug 100 is inserted into a socket in the front shell 14.
Referring now to FIG. 2 it can be seen that the aperture 20 is formed by collars 29 molded into the front and rear housing portions 14 and 16. Surrounding the collars 29 is a coil 30 wound upon an insulated core 31 composed of windings of iron tape. The coil 30 functions as the secondary of a current transformer, thereby forming a current monitor. Leads 32 are connected to the coil 30 and to an electronic circuit board 34 supported upon spars 35 cemented to the housing 14. Mounted upon the circuit board 34 is the latching relay 26 and an electronic triggering and switching circuit 36, shown schematically in FIG. 3. The relay 26 includes a coil 27, an armature 29, and contacts 42a, 42b, and 42c across the input of a full wave rectifier bridge 44. Also connected across the input to the bridge 44 is a metal oxide varistor 46. The metl oxide varistor 46 protects the rest of the circuit 36 against transients generated in the coil 30. The output of the bridge 44 is connected to a common lead 48 and a supply lead 50. An interchangeable resistor 102 mounted in the plug 100 is removably inserted in the circuit 36 to determine the level of ground fault current in the circuit 21 which will result in the device 10 being actuated. A switch arm 104 cooperates with points 106 and 107, in a manner to be more fully explained, when no rating plug is inserted. A filter comprising capacitor 52 and resistor 54 is connected across the supply and common leads 50 and 48. Transistors Q1 and Q2 are connected as a silicon controlled rectifier across the leads 50 and 48 to trigger the input of a switching device such as the thyristor 60. The thyristor 60 functions to switch power flowing from the supply lead 50 through the relay coil 27 and common lead 48. A snubbing circuit comprising resistor 62 and capacitor 64 acts to slow the voltage rise across the thyristor 60 to prevent undesired transients from activating the thyristor 60. Transient protection and noise immunity is also provided by capacitors 66, 68, and 70 and resistor 72. Capacitor 66 also stores energy to be dumped into the input of the thyristor 60 during a tripping operation. Resistors 74 and 76 serve to maintain the inputs of thyristor 60 and transistors Q1, Q2, respectively at ground level at times other than during a ground fault.
In operation, a ground fault current through the conductors of the circuit 21 surrounded by the coil 30 will produce an output signal from the coil 30 which is rectified and filtered by the bridge 44, capacitor C1, and resistor 54. The signal causes transistors Q1 and Q2 to trigger thyristor 60, causing it to conduct. Current thus flows through the relay coil 27, thereby moving the armature 29 and actuating the contacts 42a, 42b, 42c. Contacts 42a and 42b (normally closed) are opened, and contact 42c (normally open) is closed. When the contact 42b is opened, the power supply for circuit 36 is disconnected. However, the relay 26 is a latching relay and the contacts 42a, 42b, and 42c remain in the condition brought about by its actuation. An associated shunt trip circuit connected across the contacts 42c will be activated, causing the associated circuit breaker to open and take appropriate action to deenergize the conductors of the circuit 21 passing through the coil 30. Actuation of the relay 26 causes the connecting rod 45 to move upward as seen in FIGS. 1 and 2, thereby extending the reset indicating button 28 above the level of the housing 12. This provides a positive indication that a ground fault has occurred on the circuit being protected. The relay 26 will remain in this position until the reset indicating button 28 is manually depressed. This moves the armature 29 and resets the position of the contacts 42a, 42b, and 42c to the condition shown in FIG. 3.
As can be seen more clearly in FIG. 4, the resistor 102 is mounted upon an insulating base 108 of the rating plug 100 and is electrically connected to two connecting pins 110. Also connected to the base 108 is a switch member, or pin, 112. An insulating cap 114 is cemented to the base 108 to enclose the resistor 102.
Referring to FIGS. 3, 4, 5, and 6, it can be seen that the circuit board 34 includes a switch arm 104 having bifurcated ends 104a and being constructed of resilient material such as spring steel. The switch arm 104 is secured at one end to the circuit board 34 and is mechanically biased upward toward the circuit board 34 so that its bifurcated ends normally rest upon points 106 and 107 attached to the circuit board 34. In this position the switch arm electrically connects the points 105, 106 and 107 as seen in FIG. 3. Thus the resistance of a potentiometer 109 and a resistor 111 determine the level of ground fault current which will result in a tripping operation of the device 10. In this condition the device 10 is most sensitive and will trip on a small amount of ground fault current; for example, 5 amperes. The filter composed of capacitor 52 and resistor 54 is connected in the circuit to provide energy storage for more positive tripping action at low ground fault current levels. By using a small, low-voltage capacitor 52 for low ratings and switching the capacitor out of the circuit for higher ratings at which higher voltages are generated, the circuit 36 can be made more compact. Providing a bifurcated switch arm 104 insures positive contact with the points 106 and 107.
Insertion of a rating plug 100 in the device 10 causes a resistor 102 to be electrically inserted in series with potentiometer 109 and resistor 111 through the pins 110. In addition, the pin 112 contacts the switch arm 104, causing it to move away from the contacts 106 and 107. Insertion of the additional resistance of the resistor 102 in the circuit 36 reduces the sensitivity thereof. That is, a higher level of ground fault current flow through the circuit 21 is required before the device 10 will actuate. By inserting a variety of rating plugs having resistors 102 of larger and larger value, the ground fault current trip level can be increased to any desired value. For higher trip current levels, filter 52, 54 is no longer needed, and is disconnected by inserting the rating plug.
By combining the current monitor, electronic circuitry, and relay in a single unitary housing, the invention eliminates the necessity to position and mount two or more devices as was necessary using separate current monitors and sensors. This also eliminates the necessity of a connection between the current monitor and sensor, thereby reducing installation costs and avoiding any possible spurious responses due to noise pickup on the connecting leads. Providing a variety of interchangeable removable rating plugs allows a single device to be used to provide protection on circuits requiring a variety of ground fault current trip levels. Since the described device is self-powered, it eliminates the necessity to route, install, and connect power leads for the sensor. It can be seen therefore that the present invention provides a ground fault protective device which is lower in cost, simpler to install, and more versatile, while providing improved performance over the prior art. | A self-powered self-contained ground fault protective device including a current monitor, an electronic circuit for amplifying the output of the current monitor, a relay connected to the amplifying circuit and adapted to operate whenever ground fault current through the current monitor rises above a predetermined level, and an interchangeable rating plug including means for activating a circuit board switch. The current monitor, amplifying circuit, and relay are all supported and enclosed by a molded insulating housing. The rating plug is inserted into a socket on the exterior of the housing. | 7 |
BACKGROUND OF INVENTION
This invention relates to an internal combustion engine and more particularly to an improved, compact and easily manufactured, variable valve driving mechanism for such engines.
In order to improve the performance of internal combustion engines throughout their entire load and speed ranges, it has been proposed to employ a variable valve actuating mechanism that will vary the timing of one or more of the camshafts of the engine relative to the engine crankshaft and/or the degree of lift of the valve. By changing the valve timing and/or lift, it is possible to improve the performance for a variety of specific running conditions.
Conventionally, the variable valve timing mechanisms have employed some form of phase shifting mechanism in the drive of the camshafts so as to achieve the variation in the valve timing. These mechanisms are normally hydraulically operated and employ control valves that are mounted on the engine and which supply controlling pressure to the variable valve timing mechanism. Also the amount of valve lift can also be varied hydraulically.
Generally these control valves are comprised of a valve spool and a valve actuator, normally in the form of an electrically operated solenoid. It has been the practice to mount these valves in proximity to the camshafts so as to simplify the plumbing associated therewith and to avoid pressure losses.
One way this may be done is as shown in U.S. Pat. No. 6,289,861, assigned to the assignee hereof. As shown in that patent, the control valves are mounted so that they extend perpendicularly to the mating faces of the cylinder head and cam caps and in close proximity thereto. As shown in that patent, this results in, the positioning of the actuating solenoid in a vertically upstanding position and projecting substantially through the cam cover for the engine. Although this is acceptable in some applications, in many engine applications such projections are undesirable.
It is, therefore, a principal object to this invention to provide an improved actuating control valve mechanism for the variable valve actuating arrangement of an internal combustion engine.
It is another object to this invention to provide an improved and compact arrangement for mounting the control valve of a variable valve actuating mechanism for an internal combustion engine.
Normally the control valve receives oil from the engine lubricating system and delivers it through passages formed in the cylinder head and/or cam bearing cap to communicate with the variable valve actuating mechanism through passages that are formed in the camshaft and generally extend longitudinally there through. This requires the provisions of several passages including a supply passage and a return passage. The supply passage communicates to one of two chambers of the variable valve actuating mechanism and the return passage is connected to the other of these chambers of the valve actuating mechanism. The pressure in these chambers is varied to change the position of the variable valve timing mechanism to achieve the change in valve timing and/or lift.
Obviously, the provision of these multiple passages presents some problems and generally it has been the practice to form the passages primarily through drillings in the various engine components. This can give rise to several difficulties and also is costly.
It is, therefore, a still further object to this invention to provide an arrangement for the control valve communication with the variable valve timing mechanism wherein at least some of the supply passages can be formed in the interface between mating components without requiring drilling.
SUMMARY OF INVENTION
The features of the invention are adapted to be embodied in an internal combustion engine comprised of a cylinder head member adapted to be affixed in closing relation with at least one cylinder bore to form a variable volume combustion chamber with a piston reciprocating in the cylinder bore. At least one valve is supported for reciprocation in the cylinder head for serving the combustion chamber. A camshaft is journalled in the cylinder head and a cam cap that is affixed to the cylinder head for operating the valve. A hydraulically operated variable valve actuating mechanism operates the valves from an engine driven shaft and varies the timing and/or lift thereof. A control valve selectively controls the operation of the hydraulically operated variable valve actuating mechanism. The control valve has a spool portion and an operating portion for effecting reciprocation of the spool portion.
In accordance with a first feature of the invention, a fitting opening extends through the cam cap and is aligned with a corresponding fitting opening in the cylinder head. The fitting openings have their axes extending perpendicularly to facing and abutting surfaces of the cam cap and the cylinder head. The control valve is disposed in substantial part in the fitting openings with only a small portion of the control valve operating portion extending through an opening in an associated cam cover and outwardly of the area enclosed thereby.
In accordance with another feature of the invention, the control valve supplies fluid to and exhausts fluid from the variable valve timing mechanism through a plurality of passages formed in the internal combustion engine. At least one of these passages is formed by a recess formed in facing and abutting surfaces of the cam cap and the cylinder head.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a cross sectional view taken along the line 1 — 1 of FIG. 2 and through the upper portion of one bank of an internal combustion engine constructed in accordance with an embodiment of the invention.
FIG. 2 is a top plan view of the cylinder head illustrated in FIG. 1 with the cam cover removed and portions broken away so as to more clearly show the construction.
FIG. 3 is a bottom view of the cam cap with the camshafts shown in phantom.
FIG. 4 is a further enlarged cross sectional view looking in the same direction and taken along the same plane as FIG. 1 and shows the lubricant flow path from the control valve.
DETAILED DESCRIPTION
Referring now in detail to the drawings, an internal combustion engine constructed in accordance with an embodiment of the invention is indicated generally by the reference numeral 11 and is shown only partially. That is, only the cylinder head assembly, indicated generally by the reference numeral 12 , of one bank of a V-type engine is illustrated because the invention deals primarily with the variable valve timing mechanism for the engine. Therefore, where any components of the engine 11 are not illustrated, those skilled in the art will readily understand that the construction may be of any desired or known type.
As noted, the engine 11 is of the V-type and for the aforenoted reasons only one cylinder bank is shown. It will be readily apparent to those skilled in the art that the invention can be utilized with engines having other configurations and with any number of cylinders. Also, the engine 11 is primarily intended for use in a vehicle such as an automobile or motorcycle and thus, must have a compact construction.
The cylinder head assembly 12 is comprised of a main cylinder head member, indicated generally by the reference numeral 13 , and which is formed from a suitable material such as aluminum or an aluminum alloy. A cam cover 14 is detachably affixed to the cylinder head member 13 in a known manner and encloses a cam chamber 15 in which the valve actuating mechanism, now to be described, is positioned.
As may be best seen in FIGS. 1 and 2, there are journalled in the cylinder head assembly 12 a pair of camshafts, each indicated generally by the reference numeral 16 , and one of which forms.an intake camshaft and the other which forms an exhaust camshaft. As seen in FIG. 2, each of these camshafts 16 is provided with a plurality of pairs of cam lobes 17 each associated with a respective cylinder of the engine for operating a respective pair of valves through thimble tappets 18 . In other words, the engine 11 is of the four valve per cylinder type. Although this type of valve actuating mechanism is described, it will be readily apparent to those skilled in the art that other forms of valve actuation and valve layouts can be employed in accordance with the invention.
The camshafts 16 and 17 are journal led in the cylinder head assembly 12 and specifically at spaced locations along their length by bearing caps 19 that are disposed between adjacent cam lobes 17 and which are affixed to the main cylinder head member 13 by threaded fasteners 21 in a manner well known in the art.
In accordance with the invention, there is further provided adjacent the forward ends of the camshafts 16 a common forward or main bearing cap 22 by which the ends of the cam shafts 16 are journaled in a manner that will be described shortly. This main bearing cap 22 and the cylinder head member 13 have facing surfaces 23 that are held in abutting engagement. This is accomplished by pairs of threaded fasteners at each side comprised of threaded fasteners 24 and 25 . These threaded fasteners 24 and 25 are threaded into appropriate tapped holes formed in the cylinder head member 13 .
Between the threaded fasteners 24 and 25 , the main bearing cap member 22 has bearing surfaces 26 that engage bearing surfaces for the camshaft 16 . In a like manner, the cylinder head member 13 is provided with complimentary bearing surfaces 27 . The rotational axes of the camshafts 16 defined by these bearing surfaces 26 and 27 are indicated by the center lines 28 .
Although any type of arrangement may be employed for transmitting drive from the engine crankshaft or another shaft or shafts which are rotated in time with the crankshaft, a timing drive, indicated generally by the reference numeral 30 is illustrated as one of many with which the invention can be utilized. This includes an engine shaft driven chain 29 that is entrained around a driven sprocket 31 fixed, in a manner to be described, to the camshaft 16 adjacent the valley between the cylinder banks.
This driven sprocket 31 includes a variable valve timing (VVT) mechanism of any suitable, hydraulically operated type so that the relative angular relationship of the camshaft 16 can be adjusted, in a manner to be described shortly. In addition, the sprocket 31 has a sleeve portion 32 which encircles the forward portion of the camshaft 16 and which terminates at its rear end in a driving sprocket 33 .
This driving sprocket 33 is contained within the valve chamber 15 and drives a timing chain 34 from which a further sprocket 35 is driven. The sprocket 35 has a cylindrical portion 36 which encircles the remaining camshaft 16 is journaled in the bearing cap 27 . At its forward end, this sprocket cylindrical portion 36 drives a second variable valve timing mechanism 37 by which the timing relationship of the associated camshaft 16 can be varied. In other words, the variable valve timing mechanism in the sprocket 31 drives and controls the timing of the right hand camshaft 16 shown in the figures while the variable valve timing mechanism 37 drives and controls the timing of the remaining of the camshafts 16 .
The variable valve timing mechanisms 31 and 37 each are of a type that employ a pair of hydraulic chambers which are selectively pressurized or communicated with a return to the oil reservoir in order to provide the axial shifting necessary to change the relative rotational position of the associated camshaft 16 relative to the engine crankshaft. The actual construction of these variable valve timing mechanisms can be of any known type and the invention deals primarily with the control valves for controlling their operation, indicated generally by the reference numeral 38 and the manner in which hydraulic fluid is delivered to and from these control valves.
Each control valve 38 is comprised of a lower valve portion 39 and an upper actuation portion 13 . The valve portion 39 includes a cylindrical sleeve 43 mounted in the cylinder head assembly 12 in a manner to be described and a sliding spool valve element 44 . As has been previously noted, the actuators 41 may be electrical solenoids which actuate the valve elements 44 .
Each valve portion 39 is mounted in a pair of aligned bores formed in the cylinder head member 13 and the main cam bearing cap 22 . These bores are indicated by the reference numerals 45 and 46 , respectively. These bores 45 and 46 collectively define a respective axis 47 that extends perpendicularly to a plane, indicated by the dot dash line 50 which passes through the mating surfaces 23 of the bearing cap 22 and cylinder head member 13 . The axes of rotation 28 of the camshafts 16 also lie on this plane.
The bores 45 and 46 are spaced low enough in the cylinder head member 13 so that only the upper peripheral edge of the actuating portion 41 extends through openings in the cam cover 14 that are sealed by sealing rings 48 . Thus, a very compact assembly is provided. A terminal end of the valves 38 is disposed externally of the cam cover 14 to receive a suitable electrical connector to transmit the control signals to the solenoid actuator 41 .
The oil supply to the control valves 38 will now be described. As is typical, the VVT mechanism contained within the elements 31 and 37 are operated by the lubricant from the engine and hence, an oil supply manifold 49 is crossed drilled through the cylinder head member 13 below the camshaft axes 28 . This communicates in a suitable manner with the engine oil pump, indicated schematically at 51 , through a conduit or conduits which are indicated schematically at 52 .
Cross drilled from the cylinder head surface 23 is a pair of supply passages consisting of lower smaller diameter portions 53 and upper larger diameter portions 54 with these upper portions extending to the cylinder head surface 23 . The upper bore portions 54 intersect the bores 45 of the cylinder head member 13 in which the valve sleeve 43 is positioned so as to communicate directly with inlet openings 55 formed in these valve sleeves 43 that cooperate with the lands on the valve spools 44 . This is true only at one side as i.e. the left hand side. The passage 55 at the other side communicates appropriately with the bore portion 54 . Removable oil filters 56 are positioned in recesses 60 formed in the cam bearing cap 22 for ease of servicing. That is, the filters 56 can be removed for cleaning or replacement merely by removing the bearing cap 22 .
A pair of passages 57 and 58 is formed along the length of the opposite sides of the valve sleeves 43 and these communicate with passages formed in the manner now to be described. First, there is an upper passage 59 formed by a drilling solely in the bearing cap 22 and this communicates with the bearing surface 26 formed therein and with a circumferential groove formed in the respective sleeve 32 and 36 and camshaft 16 . These grooves are shown in FIG. 2 and are identified by the reference numeral 61 .
The remaining passage is formed by a semi cylindrical, grooved passage, indicated by the reference numeral 61 and which is formed in the under surface 23 of the bearing cap 22 by a suitable machining operation, thus avoiding the necessity of drilling. The end of this slot 61 has a reducing diameter curved portion 62 which, in turn, communicates with a vertical passage 63 formed in the cylinder head member 13 and which communicates with the slot 57 .
The camshafts 16 each have a pair of longitudinally extending bores 64 and 65 which extend axially there through and communicate in a known manner with the variable valve timing mechanisms in the members 31 and 37 .
Not shown is a dump or return passage which is formed in the engine body so as to return oil from the selected one of the chambers back to the oil reservoir of the engine.
The control valves 38 are rigidly mounted to the cylinder head assembly and specifically to the bearing caps 22 by the threaded fasteners 24 or 25 and appropriate projections formed on the body of the valve portions 41 .
Thus, from the forgoing description it should be readily apparent that the described construction is not only compact but also greatly simplifies the formation of the passages for delivering and returning fluid from the VVT mechanisms and the engine lubricating system or other actuating oil supply. Although the embodiment specifically disclosed varies the valve timing, it should be readily apparent that the invention can also be employed with arrangements for varying the degree of valve lift or in systems where both timing and lift are hydraulically altered. Of course, the foregoing description is that of a preferred embodiment of the invention and various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims. | An improved arrangement for controlling the valve operation of an internal combustion engine wherein the control valves are mounted within perpendicularly extending bores formed in the cylinder head and camshaft bearing cap with the bores being deep enough so that the valves do not project significantly beyond the cylinder head. In addition, one or more of the connecting passages are formed by grooves in the mating surfaces of the cylinder head and bearing cap to avoid the necessity of drillings and particularly of drilling blind bores. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to methods and systems capable of efficiently drilling offshore wells in extremely deep water using a smaller, more economical floating vessel, along with smaller, and less expensive, drilling equipment (such as hoisting equipment, riser tensioners, mud systems, etc.) than heretofore possible. This is possible because the system is able to perform all requisite tasks and functions using a reduced diameter marine riser that dramatically reduces variable deck load and space requirements for the vessel.
In recent years, the search for oil and gas deposits has taken oil companies into ever deeper offshore waters. Floating rigs of only a few years ago were generally limited to perhaps 1,500 feet of water depth, but it is now commonplace to conduct offshore drilling operations in water depths up to 5,000 feet, and several rigs are under construction which are theoretically capable of conducting drilling operations in 10,000 feet of water or more. For extreme water depths, dynamic positioning, which is not sensitive to water depth, is commonly used for vessel station keeping.
The basic deep water drilling system is unchanged from that designed more than twenty years ago. The system employed to actually drill a well in deep water is basically an extension of that for drilling in shallower water. Typically, this system employs subsea components consisting of an 18¾″ subsea blowout preventer (BOP) stack installed at the ocean floor and coupled to a floating drilling rig at the ocean surface by a 21″ diameter marine riser system. This arrangement allows the driller to utilize the riser to convey to, and install, the typical 18¾″ API subsea BOP stack on the wellhead, and supports a well program typically including 30″, 20″, 13⅜″, 9⅝″, and 7″ casing. Occasionally, additional strings of casing and/or liner may be employed.
The major adaptation of the riser system for deeper water has been to lengthen it. Lengthening the riser requires greater material strength, thicker walls, additional and larger service lines, more exotic riser connectors and tensioner system, and thicker and denser floatation. Unfortunately, lengthening the marine riser gives rise to significant consequential rig related issues as well, which, as will be shortly disclosed, tend to dominate deep water rig design, particularly semisubmersible rig design.
All marine risers must be maintained in tension whenever they are deployed; the minimum tension requirement is that the riser not be in compression at the top of the subsea BOPs. The weight of riser which the tensioning system must support is comprised of two main elements. The first is the steel weight of the riser tubing, joining connectors, auxiliary conduits, and control lines. Syntactic foam buoyancy modules are strapped around the riser to compensate for part of the riser steel weight when the riser is in the water, but these modules add to the weight in air and increase the overall diameter of the riser to around 56″. By way of example, the weight in air of 10,000 feet of a 21″ marine riser with buoyancy modules is approximately 3,600 tons.
In addition to the steel weight, the tensioning system must provide sufficient axial tension at the top of the riser to control the stresses and displacement of the riser while the floating drilling vessel moves horizontally and vertically in response to wind, waves and current. The tension requirements increase with increasing drilling mud weights and riser offsets. This means that even after considering the buoyancy, the riser tensioners for 10,000 feet of water have a total tensioning capacity of about 1,550 tons. In addition, while the actual drilling operation only requires about 500 tons of hoisting capacity, this must be increased to 750 to 1,000 tons to handle the riser and BOPs in deep water.
The riser required for 1,500 feet of water weighed only about 150 tons in air, did not normally require much buoyancy, and could be stowed in about 1,200 square feet of deck space. The marine riser for 10,000 feet of water weighs about 3,600 tons in air and requires a storage area of about 10,500 square feet.
The marine riser is subjected to lateral forces due to ocean currents, and these forces are proportional to the riser diameter. The lateral forces are transmitted to the vessel at the surface, and ultimately must be resisted by the vessel's station keeping system. Current flow around the riser also results in vortices, which, when shed, “pluck” the riser and induce low frequency oscillations in the riser, causing stress and fatigue. The riser for 1,500 feet of water had an effective diameter of about 36″, while that for 10,000 feet of water has an effective diameter of about 56″ due mainly to the use of syntactic foam buoyancy modules. Consequently, a deep water riser is subjected to greater lateral forces and stresses than a riser designed for use in shallower water.
It is sometimes required to disconnect the riser from the blowout preventers during the course of a well to effect repairs to subsea components, or in an emergency occasioned by a station keeping failure. Prior to any planned riser disconnect, the mud in the riser is displaced with seawater with the mud being returned to the mud pits on the vessel. The mud to be displaced, and stored on the vessel, that is contained in the marine riser in 1,500 feet of water, is about 600 bbls and weighs about 200 tons. Conversely, 10,000 feet of riser contains about 3,600 bbls of mud weighing nearly 1,200 tons.
In deeper sections of an offshore well where the hole-drilling diameter is small, the rate of mud circulated through the bit is reduced proportionately. For these sections, the annular velocity of the mud returns in the 21″ marine riser is quite low, and while this is not much of a problem with shorter risers, in deeper water it is insufficient in the riser to carry drilled cutting solids to the surface, and an additional mud pump is required to circulate or “boost” the marine riser.
The overall cost of a deep water drilling unit is proportional to its displacement size, variable load requirements, and equipment capacity. By way of example, a conventional design for a shallow water drilling unit and a deep water drilling unit may have the following capabilities and costs:
ITEM
1,500′ WATER
10,000′ WATER
Vessel Variable Deck Load
2000
tons
10,000
tons
Hoisting Capacity
500
tons
1000
tons
Mud Pit Capacity
1500
bbls
5000
bbls
Mud Pump Capacity
3000
hp
6000
hp
Free Deck Space Required
7500
sq. ft.
17,500
sq. ft.
Hull Steel Weight
10,000
LT
16,000
LT
Total Building Cost
$180
million
$350
million
The increased size and cost of a deep water drilling unit are directly related to the increased length of the riser. It is postulated that the size and cost of a deep water rig will, within certain limits, be approximately proportional to the square of the riser diameter, and that if the riser diameter could be reduced to about ⅔ of its present diameter, the size and cost of a rig might be reduced by 40 percent or more.
The present invention is directed to a fully capable and functional drilling system capable of drilling, and/or, working over wells presently requiring the use of a 21″ marine riser while utilizing a reduced diameter riser. By way of example, the present invention may use a riser having a nominal diameter of about 15″. Consequently, use of the present invention will reduce the variable deck load, space requirements, hoisting, mud pit and pump capacities and, hence, the cost of a deep water floating drilling vessel.
SUMMARY OF THE INVENTION
The present invention is directed to a deep ocean drilling system for drilling an offshore well in deep water using a reduced diameter drilling riser. The reduced diameter drilling riser extends from a floating drilling vessel, such as a drill ship or a semisubmersible drilling rig, to a lower marine riser package. The lower marine riser package includes a lower marine riser package connector, a riser flex joint and possibly an annular blowout preventer. The drilling system also comprises a retrievable high pressure blowout preventer stack attached to a high pressure wellhead housing. The blowout preventer stack usually includes one or more annular preventers, one or more ram preventers, and a lower marine riser package mandrel, whereby the lower marine riser package connector may be releasably connected to the blowout preventer stack. A fluid diverter line extends from the blowout preventer stack to a fluid return mandrel, whereby the lower marine riser package connector may be releasably connected to the fluid return mandrel. Thus, the fluid return mandrel serves as an alternative, or secondary, riser support station on the blowout preventer stack. The drilling system also includes a retrievable lifting and guide frame assembly comprising an upper lifting frame and a lower guide frame. The lifting frame is connected to the lower marine riser package connector. The lower marine riser package connector and the upper lifting frame are vertically and laterally moveable within a slot formed in the lower guide frame to maintain the axial alignment of the riser and provide a pathway for controlled movement of the riser between the lower marine package mandrel and the fluid return mandrel.
The drilling system further comprises choke and kill lines, hydraulic power and control lines extending from the drilling vessel and releasably connected to the blowout preventer stack, wherein such lines remain functional and protected from mechanical damage when the lower marine riser package connector is disconnected from the lower marine riser mandrel and reconnected to the mud return mandrel. Likewise, the choke and kill lines, hydraulic power and control lines remain functional and protected from mechanical damage when the lower marine riser package is disconnected from the mud return mandrel and reconnected to the lower marine riser mandrel.
In another embodiment of the present invention, the blowout preventer stack, diverter line and fluid return mandrel are self-contained within a support frame. The lower guide frame may be releasably connected to the blowout preventer support frame. The choke and kill lines, hydraulic power and control lines are also releasably connected to the blowout preventer stack. The blowout preventer stack and the lower marine riser package each contain receptacles for the control pod and choke and kill lines.
The mud diverter line of another embodiment of the present invention includes a riser dump valve to allow well flow to be diverted to the sea at the wellhead, or to dump heavy mud from the riser without disconnecting the riser from the blowout preventer stack. The riser dump valve also allows the well to fill with seawater. The mud diverter line provides a means to independently circulate the well and the marine riser and to displace either to sea water or other fluid, such as drilling mud, while the riser is connected to the secondary riser support station. The blowout preventer stack may further include a rotating head for sealing about the drill string when the riser is connected to the fluid return mandrel. Such an arrangement would permit drilling while the riser is connected to the mud return mandrel whereby mud circulated to the drilling bit would be diverted to the riser and returned to the drilling vessel.
In another embodiment of the invention, fairings are included on all riser connection flanges and the lower marine riser package to deflect equipment being lowered in open water away from the riser to minimize or eliminate damage resulting from possible collisions.
In another embodiment of the invention, a deep ocean drilling system for drilling offshore wells from a drilling vessel includes a lifting and guide frame assembly comprising an upper lifting frame connected to the lower marine riser package connector and a lower guide frame connected to the blowout preventer stack, wherein the lifting frame restricts the vertical movement of the lower marine riser package connector and the guide frame restricts the lateral movement of the lower marine riser package connector to maintain the axial alignment of the riser and control the movement of the riser between the lower marine riser package mandrel and the secondary support mandrel. The deep ocean drilling system may comprise a guide funnel attached to the lifting frame and positioned directly above the blowout preventer stack when the lower marine riser package connector is connected to the secondary support mandrel.
In another aspect of the invention, a riser system for connecting a subsea blowout preventer stack to an offshore drilling vessel is provided which comprises a riser pipe extending from the drilling vessel to a lower marine riser package connector; a blowout preventer stack having a lower marine riser package mandrel wherein the lower marine riser package connector may be releasably connected to the lower marine riser package mandrel; a secondary support mandrel wherein the lower marine riser package connector may be releasably connected to the secondary support mandrel; and a guide frame assembly comprising a guide frame attached to the blowout preventer stack, a guide pin attached to the lower marine riser package connector, the guide pin retained within a slot formed in the guide plate, the guide plate being attached to the guide frame by one or more pivotable arms wherein the slot in the guide plate restricts the vertical movement of the lower marine riser package connector relative to the blowout preventer stack and the arms restrict the lateral movement of the lower marine riser package connector between the lower marine riser package mandrel and the secondary support mandrel to maintain the axial alignment of the riser during movement of the riser between the lower marine riser package mandrel and the secondary support mandrel. The guide frame assembly may comprise a hydraulic actuating arm attached to the guide frame at one end and attached to the arms wherein the ram can be actuated to laterally move the lower marine riser package connector from the lower marine riser package mandrel to the secondary support mandrel, or vice versa.
In another aspect of the invention, a subsea wellhead system is provided comprising a wellhead housing having an internal bore with a landing means in the bore, a casing hanger having an external shoulder for landing on the landing means of the wellhead housing, wherein the casing hanger has an internal bore with an internal landing means for supporting subsequent casing strings. By way of example, the subsea wellhead system may comprise a 18¾″ wellhead housing and a 13⅜″ casing hanger with an internal bore configured with an internal landing means for supporting subsequent casing strings. The subsequent casing strings may include a 9⅝″ casing string with a 9⅝″ casing hanger and a 7″ casing string with a 7″ casing hanger and a suitable tubing hanger.
The present invention also pertains to a method of drilling a well in deep water from a floating drilling vessel having a reduced diameter riser for connecting the vessel to the well. The method comprises the steps of providing a lower marine riser package on the end of the reduced diameter riser to connect the riser to a lower marine riser mandrel on a high pressure blowout preventer stack, disconnecting the lower marine riser package connector on the lower marine riser package from the lower marine riser mandrel, repositioning the riser over a secondary riser support mandrel on the blowout preventer stack, connecting the lower marine riser package connector to the secondary riser support mandrel, wherein a fluid diverter line provides fluid communication between the secondary support mandrel and the blowout preventer stack, and lowering a 13⅜″ casing string outside of the riser through the blowout preventer stack and into the well while the well is in fluid communication with the riser. The method further comprises installing an automatic casing fill-up float shoe on the casing to minimize casing float and, thus, buckling forces due to a lack of lateral support of the casing string from the marine riser. Alternatively, the 13⅜″ casing string may be run open ended without float equipment to minimize casing float and buckling forces.
The method may further comprise the step of using active motion compensation to affect disconnection, reconnection, and stabbing operations. An auxiliary hoist may be used to lower the 13⅜″ casing to the blowout preventer stack and into the well.
The method of the present invention may include stripping a 13⅜″ casing string through the blowout preventer stack while taking returns through the riser as the casing string is lowered into the well.
The method may further comprise providing the 13⅜″ casing string with a 13⅜″ casing hanger and landing the hanger in a subsea wellhead housing, the casing hanger having an internal bore with a landing means for landing a subsequent casing hanger on a casing string, whereby the subsequent casing hanger and casing string may pass through the reduced diameter riser. The method may further comprise running a second string of casing through the reduced diameter riser and landing its casing hanger in the bore of the 13⅜″ casing hanger.
Another embodiment of the present invention is directed to a method of running casing from an offshore vessel to a subsea wellhead comprising the steps of providing a lower marine riser package connector on the end of the reduced diameter riser to connect the riser to a lower marine riser mandrel on a blowout preventer stack; disconnecting the lower marine riser package connector from the lower marine riser mandrel; repositioning the riser over a secondary support mandrel on the blowout preventer stack; connecting the lower marine riser package connector to the secondary support mandrel; lowering a casing string outside the riser through the blowout preventer stack and into the well; landing a casing hanger for the casing string in a subsea wellhead housing, the casing hanger having an internal landing means in the bore of the hanger; releasing the lower marine riser package connector from the secondary support mandrel and reconnecting the lower marine riser package connector to the lower marine riser package mandrel on the blowout preventer; lowering a subsequent casing string through the riser and into the well; and landing the casing hanger for a subsequent casing string on the internal landing means of the previous hanger.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the arrangement of the subsea components of the reduced diameter riser system of the present invention at the seabed.
FIG. 2 is an elevational view showing a deep water drilling vessel and a riser system of the present invention.
FIG. 3 is an elevational view of the initial stages of drilling a subsea well.
FIG. 4 is an elevational view illustrating the lowering of the mud return assembly, lower marine riser package, and blowout preventer stack to the subsea wellhead.
FIG. 5 is an elevational view of the mud return assembly, lower marine riser package, and blowout preventer stack landed on and latched onto the wellhead housing.
FIG. 6 is an elevational view illustrating the lower marine riser package disconnected from the blowout preventer stack.
FIG. 7 is an elevational view illustrating the lower marine riser package repositioned over the mud return assembly.
FIG. 8 is an elevational view illustrating the drilling riser and lower marine riser package attached to the mud return assembly.
FIG. 9 is an elevation view illustrating the 13⅜″ casing string being lowered into the wellbore outside of the drilling riser.
FIG. 10 is an enlarged view of the lower marine riser package disconnected from the blowout preventer stack.
FIG. 11 is an enlarged view of the lower marine riser package positioned above the mud return assembly.
FIG. 12 is an enlarged view of the lower marine riser package connected to the mud return assembly.
FIG. 13 is an enlarged view of the 13⅜″ casing string being lowered into the wellbore outside of the riser.
FIG. 14 is an enlarged view of the lifting and guide frame assembly for the lower marine riser package and the BOP stack.
FIG. 15 is an enlarged view illustrating the operation of the lifting and guide frame assembly when the lower marine riser package is disconnected from the BOP stack.
FIG. 16 is an enlarged view of the lifting and guide frame arrangement when the lower marine riser package is connected to the mud return assembly.
FIG. 17 is an enlarged view of the disconnection of the drilling riser and the lifting and guide frame assembly from the BOP stack.
FIG. 18 is a top view of the upper lifting frame and the lower guide frame.
FIG. 19 is a top view illustrating the movement of the upper lifting frame relative to the lower guide frame.
FIG. 20 is a top view of the upper lifting frame being moved relative to the lower guide frame by means of hydraulic rams.
FIG. 21 is an elevational view of four stages in the movement of the drilling riser by an alternative mechanism comprising a guide pin, guide frame with slot, guide arms and hydraulic rams.
FIG. 22 illustrates a 30″ wellhead housing for use in conjunction with the deep ocean drilling system of the present invention.
FIG. 23 illustrates an 18¾″ wellhead housing landed inside the 30″ wellhead housing according to one embodiment of the present invention.
FIG. 24 illustrates the 13⅜″ casing hanger landed inside the 18¾″ wellhead housing.
FIG. 25 illustrates the 9⅝″ casing hanger landed inside the 13⅜″ casing hanger.
FIG. 26 illustrates the 7″ casing hanger landed inside the 13⅜″ casing hanger.
FIG. 27 illustrates a tubing hanger landed inside the 13⅜″ casing hanger according to one embodiment of the present invention.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as described by the appended claims.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While all wells are custom designed, and drilling depths and casing sizes and setting depths are adapted to the geology, one common method for drilling deep water wells is to establish the well by drilling a 36″ hole, then running and cementing a 30″ diameter conductor pipe which is fitted at the top with a wellhead housing. Alternatively, in soft bottom situations, the 30″ conductor pipe may be jetted in place utilizing an internal drill bit/jetting assembly.
A 26″ hole is next drilled through the 30″ conductor and then 20″ casing, fitted with an 18¾″ high pressure wellhead, is run and cemented. During these operations, no marine riser is used, and all well returns and cuttings are simply allowed to be circulated to the sea floor. For deep water drilling vessels, the 18¾″ wellhead is typically rated for 10,000 psi or 15,000 psi service.
An 18¾″ high pressure BOP stack is next run to the wellhead on the 21″ marine riser, and latched onto the wellhead. All subsequent drilling operations will be conducted through the marine riser and BOPs, with mud returning to the surface vessel via the marine riser. The 18¾″ BOP stack is typically rated for 10,000 psi or 15,000 psi service.
A 17½″ hole is usually drilled next, and a string of 13⅜″ casing is run and cemented in the 17½″ hole section. The 17½″ bit and 13⅜″ casing, and all smaller sizes of each will pass through the minimum 18¾″ inside diameter of the marine riser and BOP. This is followed by a 12¼″ hole and 9⅝″ casing, and an 8½″ hole and 7″ casing or liner to the well's total depth. In deep water, or in other circumstances, additional hole sections and casing and or liner strings of various sizes may be required.
The present invention will be described using the same well program as described above. However, one of skill in the art will recognize that the present invention can be adapted for use with other well programs as well as other drilling, completion or workover operations.
The arrangement of the components at the seabed according to one embodiment of the present invention is shown in FIG. 1 and consists of an 18¾″ wellhead mandrel and housing 2 installed in a 30″ wellhead housing 1 . Connected to the 18¾″ wellhead mandrel 2 is an 18¾″ blowout preventer stack comprising a wellhead connector 3 , lower ram blowout preventer 4 , lower middle ram blowout preventer 5 , upper middle ram blowout preventer 6 , upper ram blowout preventer 7 , lower annular blowout preventer 8 , blowout preventer stack flowline diverter spool 9 , upper annular blowout preventer 10 , and 18¾″ lower marine riser package connector mandrel 11 . Connected to the BOP stack is an 18¾″ lower marine riser package connector 12 , and 18¾″ lower flex joint 13 . The blowout preventer stack is a high pressure BOP stack, typically rated to 10,000 or 15,000 psi. Connected to the 18¾″ blowout preventer stack flowline diverter spool 9 is a fluid diverter line which may comprise an inner riser isolation valve 20 , outer riser isolation valve 19 , riser base flowline diverter spool 16 , inner riser dump valve 17 , outer riser dump valve 18 , and 18¾″ mud return mandrel 15 .
A reduced diameter drilling riser 14 connects these components to the drilling vessel 22 at the surface of the sea. The drilling riser is comprised of riser joints which may be connected by conventional riser connectors. The riser also includes choke and kill lines as well as control and service lines (not shown) for the subsea BOP stack 28 , lower marine riser package 27 and mud return assembly 26 shown on FIG. 2. A reduced diameter riser is defined to mean a riser having a drift diameter smaller than 17½″. Preferably, the reduced diameter riser has a drift diameter equal to or less than the coupling diameter of a standard API 13⅜″ casing. In the preferred embodiment, the reduced diameter drilling riser has a 15″ nominal outside diameter and a 14″ internal diameter or drift diameter.
FIG. 2 shows the overall arrangement of one embodiment of a deep water drilling system according to the present invention. The support structure around the blowout preventer 28 is not shown for clarity. Drilling vessel 22 includes main hoist 21 , auxiliary hoist 23 , and riser tensioners 24 . Thrusters 25 maintain drilling vessel 22 above the well to be drilled. Alternatively, mooring lines and anchors can be used to maintain station above the well. Drilling riser 14 is supported by riser tensioners 24 on drilling vessel 22 . Tensioners 24 maintain the riser in tension when the riser is connected to the well. The components on the seabed comprise a lower marine riser package 27 which as previously shown in FIG. 1 includes lower marine riser package connector 12 and lower flex joint 13 ; a mud return assembly 26 consisting of the inner riser isolation valve 20 , outer riser isolation valve 19 , riser base flowline diverter spool 16 , inner riser dump valve 17 , outer riser dump valve 18 , and mud return mandrel 15 ; and an 18¾″ blowout preventer stack 28 consisting of blowout preventer stack wellhead connector 3 , lower ram blowout preventer 4 , lower middle ram blowout preventer 5 , upper middle ram blowout preventer 6 , upper ram blowout preventer 7 , lower annular blowout preventer 8 , blowout preventer stack flowline diverter spool 9 , upper annular blowout preventer 10 , and lower marine riser package connector mandrel 11 .
During the initial stages of drilling a well with the present invention, all operations are carried out in a conventional manner as indicated in FIG. 3 . Drilling vessel 22 establishes the well by either drilling a 36″ hole for, or jetting into place, the 30″ conductor 40 . The 30″ wellhead housing 1 is attached to the top of the 30″ conductor. Following this, a 26″ hole is drilled and a string of 20″ casing 41 is lowered in the wellbore (not shown). The 18¾″ wellhead mandrel and housing 2 is attached to the top of the 20″ casing and lands inside the 30″ wellhead housing. FIG. 3 shows the 18¾″ wellhead housing 2 being landed inside the 30″ wellhead housing 1 with landing string 29 supported from main hoist 21 . Drillpipe is typically used as the landing string.
After installing the 18¾″ wellhead mandrel and housing 2 , the mud return assembly 26 , lower marine riser package 27 and blowout preventer stack 28 are lowered on the 15″ nominal diameter drilling riser 14 as shown in FIG. 4 . The mud return assembly 26 , lower marine riser package 27 and blowout preventer stack 28 are landed on and latched onto 18¾″ wellhead mandrel 2 as shown in FIG. 5 . Drilling riser 14 is suspended from the riser tensioners 24 . Since the 15″ riser is too small to pass a 17½″ bit, the 17½″ hole section is drilled using a smaller, for example a 12¼″ bit followed by a 17½″ under-reaming tool. The under-reaming tool, of which several types are available and in common use, will pass through the marine riser, and follow the 12¼″ bit to open the hole to 17½″ in diameter.
The 13⅜″ casing will not pass through the 15″ nominal marine riser, and the casing hanger at the top of the casing has a diameter of about 18⅝″, so in order to run this string of casing the marine riser must be moved out of the well path. Therefore, upon completion of drilling operations for the 17½″ hole section, the well is killed with drilling mud, the BOP is closed, the drilling riser 14 is displaced to seawater and the lower marine riser package 27 is disconnected from the blowout preventer stack 28 as shown in FIGS. 6 and 10. The drilling vessel 22 repositions the drilling riser 14 and the lower marine riser package 27 over the mud return assembly 26 and the riser and lower marine riser package is lowered to and latched onto the mud return assembly 26 as shown in FIGS. 7, 8 , 11 and 12 . The mud return assembly 26 serves as a secondary support station for the riser when the riser is removed from the well path.
The 13⅜″ casing string 31 is then made up and lowered by auxiliary hoist 23 into the wellbore outside the 15″ nominal diameter drilling riser on landing string 30 as shown in FIGS. 9 and 13. Alternatively, the 13⅜″ casing may be assembled and lowered into the water with the auxiliary hoist while the 17½″ hole section is being drilled. The 13⅜″ casing string may include an automatic casing fill-up float shoe and cement wiper float collar to minimize the casing float and, thus, the buckling forces due to the casing string being laterally unsupported by the marine riser. Alternatively, the casing string may be run open ended without float equipment. In either case, the casing string will be allowed to fill with well bore mud as the casing string is lowered into the wellbore. Automatic casing float shoes and cement wiper float collars are well known in the art.
Since the 13⅜″ casing string is being run in open water conditions outside of the reduced diameter riser, the upper end of the marine riser is located as far up current as possible so as to minimize the possibility of collision of the casing string with the riser. The 13⅜″ casing string and the drillpipe landing string are quite flexible in deep water, and will be deflected from the vertical axis by current forces acting upon them. While the vertical velocity of the casing being run is not great, the mass is huge, and collisions with the riser should be avoided particularly while the casing is being lowered vertically in open water. Fairings may be included on all riser connection flanges in the lower marine riser package to deflect equipment being lowered in open water away from the riser to minimize or eliminate damage resulting from possible collisions. To avoid collisions between the casing string and the marine riser, it is necessary to ensure that the unsecured lower end of the casing is carried away from the riser and BOP by any current while lowering the casing through the water. Once the casing string reaches the vicinity of the blowout preventer stack, the drilling vessel can be repositioned with the thrusters, or mooring lines, to align the bottom of the casing string with the wellbore, and allow the casing string to enter the blowout preventer stack. A guide funnel may be used to facilitate entry. Cameras including those installed on a remote operating vehicle (ROV) may be used to assist the lowering of the casing string into the blowout preventer stack. ROVs, and their use, are well known in the art for subsea operations.
When the 13⅜″ casing string has been landed inside the 18¾″ wellhead housing 2 and cemented in place, the drilling riser 14 is again displaced to seawater and disconnected from the mud return assembly along with the lower marine riser package and returned to the original position on top of the blowout preventer stack 28 as shown in FIG. 5 . Drilling operations from this point on are conducted through the 15″ nominal diameter drilling riser 14 with no further need to perform the disconnection and relocation operation. This is based on using a novel wellhead design that will accommodate casing hangers of a smaller diameter than the inside diameter of the marine riser for the 9⅝″ and 7″ casing strings.
FIGS. 10 through 13 show the above process in more detail. In FIG. 10, drilling riser 14 , lower flex joint 13 and lower marine riser package connector 12 are disconnected from the lower marine riser package connector mandrel 11 and the remainder of the blowout preventer stack.
In FIG. 11, drilling riser 14 , lower flex joint 13 and lower marine riser package connector 12 have been moved over to a position directly above mud return mandrel 15 . The drilling riser 14 , lower flex joint 13 and lower marine riser package connector have been lowered onto and connected to mud return mandrel 15 in FIG. 12 . FIG. 13 shows the 13⅜″ casing string 31 being lowered into the wellbore through the blowout preventer stack on landing string 30 .
U.S. Pat. No. 4,147,221 to Ilfrey describes a pivotable, hydraulic toggle arrangement wherein the riser connector is relocated from a primary to an alternative support. However, because the device moves the connector in a semicircular arc, the riser connector would be axially missaligned by a significant amount when the connector receptacle initially engages the mandrel. The connector will not tolerate more than a few centimeters of axial misalignment during connection or disconnection and the resulting interference would prevent the connector from mating and locking. To avoid this problem, one embodiment of the present invention includes a two piece lifting and guide frame assembly shown in FIGS. 14 through 19 which maintains the riser in axial alignment during disconnection, transport and reconnection between the mandrel 11 and mud return mandrel 15 .
The lower flex joint 13 , lower marine riser package connector 12 , riser 14 and guide funnel 32 are joined together by means of upper lifting frame 33 . These components can move laterally within the limits of slot 34 a in the lower guide frame 34 as shown in FIG. 18, but are restrained from moving further than required to effect the relocation of these components. Choke and kill lines 39 , BOP control lines 42 and other service lines (not shown) can remain connected to the blowout preventer stack throughout the range of movement of the lower marine riser package 27 within the lower lifting and guide frame 34 . More particularly, choke and kill lines 39 , pod control lines 42 and other service lines (not shown) remain connected at all times to the blowout preventer stack by means of control pod 36 and choke and kill line connectors 38 during the relocation of the lower marine riser package between the lower marine riser package mandrel 11 and the mud return mandrel 15 , or vice versa.
FIG. 18 shows a plan view of the upper lifting frame 33 with guide funnel 32 and drilling riser 14 . Also shown is lower guide frame 34 containing a slot 34 a which allows the upper lifting frame 33 and its attached components to move vertically and horizontally within the restricted confines of slot 34 a. Vertical movement of the lower marine riser package 27 relative to the lower guide frame is determined by the distance between the upper and lower plates of the upper lifting frame 33 . As illustrated in FIG. 15, once connector 12 has been released, the vertical travel of the lower marine riser package and the riser is restricted by the contact of the lower plate of lifting frame 33 with the top plate of guide frame 34 . FIG. 19 shows the range of horizontal movement of upper lifting frame 33 within slot 34 a. This permits the drilling riser 14 to be moved from a position above the BOP stack 28 to a position above the mud return mandrel 15 in a restricted and controlled manner.
Alternatively, the vertical travel of the lower marine riser package 27 relative to the guide frame can be accomplished without the upper lifting frame. In such arrangement, the vertical travel of the lower marine riser package would be upwardly limited by the contact of the top of the enlarged diameter portion of connector 12 with the top plate of lower guide frame 34 . The smaller diameter portion of connector 12 would be positioned within slot 34 a for controlling the lateral movement of the lower marine riser package with respect to the blowout preventer stack.
Movement of the drilling riser may be effected by relocating the drilling rig 22 sufficiently to allow the drilling riser to swing over beneath it. The swing is restricted and contained by the lifting and guide frame assembly and slot 34 a arrangement. An alternative to relocating the drilling rig 22 is to attach hydraulic rams between the upper lifting frame and the lower guide frame and hydraulically drive the upper lifting frame 33 to alternative locations within the confined of slot 34 a. FIG. 20 shows the upper lifting frame 33 and guide frame 34 with attached hydraulic rams 35 . Hydraulic rams 35 are pivotably attached at their lower end to lower guide frame 34 and at their upper end to upper lifting frame 33 .
FIGS. 14-16, 18 and 19 illustrate in more detail how the drilling riser 14 , lower flex joint 13 and lower marine riser package connector 12 may be hydraulically disconnected from the blowout preventer stack and moved in a controlled manner along a controlled pathway and connected to the mud return assembly in accordance with one embodiment of the present invention. Throughout the process, choke and kill lines 39 , pod control lines 42 and other service lines such as television electric cables (not shown) must be connected to the blowout preventer stack at all times. In addition these lines must be protected from damage while the riser is being moved. The lower marine riser package connector mandrel 11 must also be protected while lowering casing and other components inside the wellbore and these components must be guided into the lower marine riser package connector mandrel 11 opening.
FIG. 15 shows the riser 14 , lower flex joint 13 and lower marine riser package connector 12 disconnected from lower marine riser connector mandrel 11 and raised to allow lower marine riser package connector 12 to clear the lower marine riser connector mandrel 11 . These components are vertically restrained from moving further than desired by lower guide frame 34 which remains connected to blowout preventer stack support frame 35 by means of guide frame connectors 37 .
FIG. 16 shows the riser 14 , lower flex joint 13 and lower marine riser package connector 12 moved over to a position directly above the mud return assembly and connected to the mud return mandrel 15 . The lateral movement of these components is restricted by slot 34 a in lower guide frame 34 . Guide funnel 32 is in position directly above the blowout preventer stack to protect the lower marine riser package connector mandrel and to guide casing or drilling tools into and out of the wellbore. As shown in FIGS. 14-16, choke and kill lines 39 , pod control lines 42 and the other service lines remain connected to the blowout preventer stack throughout this operation.
In the event of an emergency that requires the disconnection of the drilling riser 14 from the blowout preventer stack 28 , the control pod 36 , choke and kill line connectors 38 and guide frame connectors 37 are released from the blowout preventer stack allowing the drilling riser joints 14 , lower marine riser package 27 , lower guide frame 34 , control pods 36 , choke and kill lines 39 and other service lines (not shown) to be retrieved from the blowout preventer stack to the drilling vessel 22 as shown in FIG. 17 . The release is accomplished by means of the electro-hydraulic BOP control system which operates the required connectors in sequence to effect the disconnect. When the connectors have been released, the riser string 14 and lower marine riser package 27 are raised clear of the blowout preventer stack 28 by using the riser tensioners 24 or hoisting equipment 21 on the drilling vessel 22 . This disconnection process can be conducted with the riser 14 and lower marine riser package 27 in any position.
The riser relocation may be accomplished by reducing the riser tension on the tensioners to the point where tension at the lower marine riser package connector 12 is slightly positive, releasing the connector which will be pulled free of the lower marine riser package mandrel by increasing the tension on the riser tensioners, and then repositioning the connector over the mud return mandrel. After the connector has been transported to the secondary location over the mud return mandrel, the tensioners can be slacked slightly to land the connector on the mandrel and the connector re-latched before tension is increased to the required amount. Alternatively, the upper end of the riser may be supported by the rig hoist and drawworks system during this process, and the transfer may be accomplished by maneuvering the vessel while the riser is supported by the hoist. If the hydraulic ram assembly illustrated in FIG. 20 is utilized, the riser is hydraulically driven from mandrel 11 to mud return mandrel 15 , or vice versa, by hydraulic rams 35 after the lower marine riser connector 12 has been released and pulled free from the respective mandrel to which it had previously been connected.
An alternative means for relocating the drilling riser 14 is shown in FIGS. 21 ( a ), ( b ), ( c ), and ( d ). In FIG. 21 ( a ) lower marine riser package connector 12 is shown attached to lower marine riser connector mandrel 11 . Guide pin 44 attached to lower marine riser package connector 12 is retained within a vertical slot 46 formed in guide plate 45 . The guide plate 45 is attached to lower marine riser package guide frame 49 by means of parallel arms 48 which are pivotably attached at their lower ends to frame 49 and at their upper ends to the lower end of plate 45 . The position of the lower marine riser connector 12 and hence drilling riser 14 is controlled in the vertical plane by hoisting and lowering to the extent permitted by guide pin 44 within vertical slot 46 and in the horizontal plane by actuating hydraulic ram 47 to move the lower marine riser connector 12 and hence drilling riser 14 back and forth to the extent permitted by the hydraulic ram 47 and parallel arms 48 .
In FIG. 21 ( b ) the lower marine riser connector 12 (and drilling riser 14 ) has been disconnected from lower marine riser mandrel 11 and hoisted upwards until guide pin 44 reaches the top of vertical slot 46 . Hydraulic ram 47 remains in the fully retracted position. In FIG. 21 ( c ) hydraulic ram 47 has been extended fully driving lower marine riser connector 12 (and hence drilling riser 14 ) to a position directly above mud return mandrel 15 . In FIG. 21 ( d ) the lower marine riser connector 12 (and hence drilling riser 14 ) has been lowered over and connected to mud return mandrel 15 . The guide pin 44 is now at the lower end of vertical slot 46 .
Although not shown, lower marine riser package guide frame 49 may be releasably connected to blowout preventer stack 28 with guide frame connectors in the s same manner that guide frame connectors 37 connected lower guide frame 34 to the BOP stack. Similarly, choke and kill lines, pod control lines and other service lines remain connected at all times to the blowout preventer stack by means of a control pod and choke and kill line connectors during the relocation of the lower marine riser package between mandrel 11 and mud return mandrel 15 , or vice versa, using the arrangement shown in FIGS. 21 ( a )- 21 ( d ).
A fundamental part of this present invention is the BOP stack arrangement which allows full well control operations during the entire course of the well. This requires that the choke and kill lines, riser booster lines (if required), and all sub-sea and BOP controls be fully functional when the riser is in the alternative position, i.e., disconnected from the top of BOPs and connected to the alternative support station of the mud return assembly. The alternative support station is an integral part of the BOP stack frame, and is further equipped with a conduit and appropriate valves, which allow mud returns from beneath the upper, annular blowout preventer. This is to allow mud to be displaced into the riser when said annular is fully or partially closed as in stripping operations.
The upper end of the riser 14 is supported by a telescoping joint, which is attached to a diverter under the rotary table, and axially in the well path. While Ilfrey et al proposed shifting the upper end of the riser out of the well path, in the preferred embodiment of the present invention illustrated in FIG. 9, the upper end of the riser is not disturbed, and the 13⅜″ casing is run and landed using auxiliary hoist 23 located several meters from the primary hoist. The auxiliary hoist is preferably motion compensated and equipped with a rotary table. Use of auxiliary hoist 23 allows an operator to make up and suspend the 13⅜″ string vertically proximate to the top of the subsea BOP stack prior to the completion of the 17½″ hole section. Upon completion of the 17½″ hole section and the relocation of the riser to the mud return assembly, valuable rig time is saved by lowering the already suspended 13⅜″ casing through the BOP stack and into the wellbore.
The 13⅜″ casing is run through open water into the BOP stack, the casing hanger is landed in the wellhead, and the casing cemented. Displaced mud during these operations may be to the ocean floor through the open BOPs, or the annular preventer 10 may be closed and the string stripped into the hole with resulting returns to the rig via the marine riser. In the event the well begins to flow during the running of the 13⅜″ casing, annular preventer 10 may be closed about the casing and the casing string stripped into the hole while maintaining wellbore control via the mud return assembly. Alternatively, by taking mud returns through the riser via the mud return assembly, the mud returns may be monitored while running the casing to verify that the correct amount of mud is being displaced by the casing and the well is not beginning to flow. Thus, the mud return assembly of the present invention provides improved well safety during the open water casing operations.
The BOP stack arrangement must conform to certain regulatory standards which establish the type and quantity of ram and annular preventers, but generally a BOP stack will consist of a wellhead connector, three to five ram preventers, one or two annular preventers, and lower marine riser package mandrel as shown in the attached figures. For purposes of the present invention, it will be understood that a high pressure BOP stack shall mean a BOP stack having ram preventers rated for 10,000 psi or higher service. The lower marine riser package mandrel provides a connection for the lower marine riser package connector and allows the riser to be connected and disconnected to the top of the BOP stack. The lower marine riser package (LMRP) consists of the riser connector attached to the riser with a flexible joint, the choke and kill line connectors, and control pods. As shown in FIG. 14, the BOP stack is integrated and supported by a steel support frame fixed at various points to the BOP components The subsea BOP stack may consist of a number of main and auxiliary components that are unitized or integrated within the support frame. The support frame serves other functions such as mechanical support for components, handling, support, and to stabilize the stack when the stack is lifted and placed on the deck of the drilling vessel. The frame is usually made up of four vertical tubular members spaced around the BOP stack, each connected to the adjacent one by means of tubular cross braces and bolted flanges. The LMRP may include a guide frame assembly which may interface with the main stack frame. The steel frames are usually built with bolted flanges to allow portions to be removed for access to BOP components.
The blowout preventer stack for the present invention is similar, but includes an alternative mandrel 15 for the LMRP adjacent to the primary mandrel and supported by and fixed to the BOP stack and/or support frame. This mandrel 15 is connected by a conduit and suitable valves to the wellbore below the upper annular preventer, so that when the upper annular preventer of the BOP is closed, the well returns may be diverted to the alternative riser connector (mud return) mandrel 15 . Additional valves allow the alternative riser connector mandrel 15 to be opened to the sea. This manifold of valves also allows well returns to flow up the riser when the latter is in the alternative location, or to flow to the sea. It also allows the riser or the well to be flooded with sea water.
Conventional 18¾″ high pressure subsea wellhead systems generally have a through bore diameter of about 18¾″ down to the casing hanger shoulder. The shoulder or landing ring whereon the 13⅜″ casing hanger is landed bears the vertical load of the casing string. A seal and lock down is usually installed above the landing ring between the casing hanger and the bore of the wellhead. Each subsequent casing hanger lands on top of the preceding hanger, and is sealed and locked down to the 18¾ wellhead bore. The 13⅜″ casing hanger typically bears the vertical load for all smaller casing strings, and transfers this load to the 18¾″ wellhead housing. Since all casing hangers in this system have an external diameter of about 18⅝″, the casing hangers cannot pass through the nominal 15″ marine riser.
One embodiment of the present invention contemplates a novel wellhead wherein the 13⅜″ casing hanger lands on the 18¾″ wellhead landing ring and seals against the bore of the wellhead housing as in conventional technology. The 13⅜″ casing hanger, however, will be extended in length as required and its internal bore will include a landing means for the 9⅝″ casing hanger. The 9⅝″ hanger will in turn be sealed against and locked down in the 13⅜″ casing hanger bore. Subsequent casing and tubing hangers will be landed inside the 13⅜″ casing hanger and stacked upon on the 9⅝″ hanger. This will allow all casing strings, hangers, and wear bushings subsequent to the 13⅜″ casing to pass through the 15″ marine riser.
The operation of the system with the novel wellhead for a typical subsea well system consisting of 30″, 20″, 13⅜″, 9⅝″, and 7″ casing strings and 4½″ production tubing string is illustrated in FIGS. 22 through 27.
The 30″ conductor 62 is drilled or jetted into place conventionally with a 30″ wellhead housing 61 attached. The 26″ hole section is drilled next and 20″ casing 63 run. Attached to the top of the 20″ casing 63 is 18¾″ wellhead housing 64 which is configured to operate with the proposed well system. The 18¾″ wellhead housing 64 lands off inside the 30″ wellhead housing 61 conventionally as shown in FIG. 23 .
The 17½″ hole section is then drilled and 13⅜″ casing 66 run. The 13⅜″ casing is attached to a novel casing hanger which lands on the landing shoulder of wellhead housing 64 as shown in FIG. 24 . The 13⅜″ casing hanger 65 is configured to permit the internal hang-off and sealing of all subsequent casing hangers and the tubing hanger. In the preferred embodiment, the internal bore of the 13⅜″ hanger is machined to include a landing shoulder 73 for the 9⅝″ casing hanger. Alternatively, the internal bore may be configured to include other known landing means such as a hardened landing ring or grooves for receiving load rings attached to the subsequent casing hangers.
Next, the 12¼″ hole is drilled and 9⅝″ casing 68 is run into the well. The 9⅝ casing hanger 67 is landed on the landing shoulder inside the 13⅜″ casing hanger 65 as shown in FIG. 25 . Similarly, the 8½″ hole section is drilled and 7″ casing 70 is run into the well. The 7″ casing may be hung off in the 9⅝ casing as a liner or extend back to surface. In the later case, a 7″ casing hanger 69 is landed in the 13⅜″ casing hanger 65 as shown in FIG. 26 .
Afterwards, production tubing 72 and tubing hanger 71 are run and landed inside the 13⅜″ casing hanger 65 as shown in FIG. 27 . The 13⅜″ casing hanger 65 supports the vertical load of the 9⅝″ casing, the 7″ casing and the tubing string. This load is transmitted through load shoulder 75 to the 18¾″ wellhead housing.
While the description of the preferred embodiment of the invention contemplates the use of a 15″ riser and running only the 13⅝″ casing string outside the riser, even smaller risers might be employed. For example, an approximately 11½″ riser could be used with appropriate modifications to the wellhead equipment, casing and tubing hangers, and procedure. This would allow all hole sections under the 9⅝″ casing to be conducted conventionally assuming the wellhead has been reconfigured to accommodate smaller diameter hangers for 7″ (or smaller) casing and tubing.
Alternatively, the riser may be located on the mud return mandrel during the entire course of the well, with well equipment stripped through or staged through the blowout preventers. Should drilling be contemplated while the riser is connected to the mud return mandrel, mud circulated through the drilling bit must be diverted to the riser for return to the drilling vessel. This requires sealing the annular area around the drill string above the diverter spool. The drill string has a somewhat irregular profile as the drillpipe joints have a larger outside diameter than the remainder of the drillpipe body. In one embodiment of the invention, the seal would be effected by energizing the upper annular preventer to the extent that the element seals against the drillpipe, but not so tightly that the pipe is immobilized. This is accomplished by regulating the hydraulic pressure in the annular preventer closing and/or opening chambers. An accumulator may be required in the hydraulic circuit to allow a volume of hydraulic fluid to be displaced, and thus maintain a constant pressure, as the preventer element is forced open by a tool joint passing through the preventer. This operation is referred to as “stripping” and is well known in the art. The wear on the blowout preventer element at constant actuation pressure is proportional to the distance the pipe moves, and the element will tolerate a fair amount of linear motion without undo wear. The wear on the preventer element increases if the drillpipe is rotated. Accordingly, according to one embodiment of the invention, a downhole motor is used to rotate the drill bit while the drillpipe would only be rotated very slowly when required, if at all. Alternatively, a full opening rotating head may be utilized during drilling operations where the riser is located on the mud return mandrel. The sealing element of the rotating head rotates within the apparatus while sealing against the drillpipe, dramatically reducing wear on the element due to such rotation. Rotating head blowout preventers are well known in land drilling applications and are believed to be adaptable to work in subsea environments.
Other modifications and embodiments of the present invention are possible without departing from the scope thereof. All matter herein set forth and shown in the accompanying drawings is intended to be illustrative and not limiting. Accordingly, the foregoing description should be regarded as illustrative of the invention as defined by the claims appended hereto. | A deep ocean drilling system is disclosed for drilling offshore wells in extremely deep water using smaller and more economical drilling vessels. The system utilizes a reduced diameter drilling riser that reduces the size and cost of conventional floating drilling unit. The reduced diameter drilling riser is detached from the blowout preventer stack and repositioned and attached to a mud return assembly. Large diameter casing is lowered into the wellbore outside of the reduced diameter riser. Thereafter, the reduced diameter drilling riser is released from the mud return assembly and repositioned over and reconnected to the blowout preventer stack. | 4 |
BACKGROUND OF THE INVENTION
[0001] The subject matter disclosed herein relates to gas turbine systems, and more particularly to plasma actuators disposed within such systems.
[0002] Inlet assemblies for gas turbine systems typically include an intake portion that provides an intake path for an airstream to enter the inlet assembly and the intake portions often include conditioning features such as weather hoods or louvers. Downstream of the louvers or hoods, various filtration and airstream conditioning components may be included to treat the airstream. An inlet duct is configured to contain and route the treated airstream to a gas turbine inlet plenum, and subsequently to an inlet portion of a compressor. Routing of the airstream through the inlet assembly typically includes changes in geometry and/or rapid redirection of the airstream, thereby causing flow separation at various regions and results in an undesirable pressure drop of the airstream.
BRIEF DESCRIPTION OF THE INVENTION
[0003] According to one aspect of the invention, a gas turbine system having a plasma actuator flow control arrangement including a compressor section for compressing an airstream, wherein the compressor section includes at least one inlet guide vane for controlling the airstream proximate an inlet portion of the compressor section. Also included is a turbine inlet assembly for ingesting the airstream to be routed to the compressor section. Further included is a plasma actuator disposed within at least one of the inlet portion of the compressor section and the turbine inlet assembly for controllably producing an electric field to manipulate a portion of the airstream.
[0004] According to another aspect of the invention, a gas turbine system having a plasma actuator flow control arrangement including a turbine inlet assembly for ingesting an airstream to be routed to a compressor section, wherein the turbine inlet assembly includes an outer wall enclosing an airstream path. Also included is a plasma actuator disposed proximate the outer wall of the turbine inlet assembly for controllably producing an electric field to manipulate a portion of the airstream.
[0005] According to yet another aspect of the invention, a gas turbine system having a plasma actuator flow control arrangement including a compressor section for compressing an airstream, wherein the compressor section includes an inlet portion. Also included is a plasma actuator disposed proximate the inlet portion of the compressor section, wherein the plasma actuator controllably produces an electric field to manipulate a portion of the airstream.
[0006] These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0008] FIG. 1 is a schematic illustration of a gas turbine system;
[0009] FIG. 2 is a side, elevational view of an inlet assembly of the gas turbine system;
[0010] FIG. 3 is a schematic illustration of a plasma actuator disposed within a portion of the gas turbine system; and
[0011] FIG. 4 is a side, cross-sectional view of an inlet portion of a compressor section of the gas turbine system.
[0012] The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Referring to FIG. 1 , a gas turbine system is schematically illustrated with reference numeral 10 . The gas turbine system 10 includes a compressor 12 , a combustor 14 , a turbine 16 , a shaft 18 and a fuel nozzle 20 . The compressor 12 and the turbine 16 are coupled by the shaft 18 . The shaft 18 may be a single shaft or a plurality of shaft segments coupled together to form the shaft 18 . Additionally, a turbine inlet assembly 22 ingests an airstream 24 that is filtered and routed to the compressor 12 .
[0014] The combustor 14 uses a combustible liquid and/or gas fuel, such as natural gas or a hydrogen rich synthetic gas, to run the gas turbine system 10 . For example, fuel nozzles 20 are in fluid communication with an air supply and a fuel supply 26 . The fuel nozzles 20 create an air-fuel mixture, and discharge the air-fuel mixture into the combustor 14 , thereby causing a combustion that creates a hot pressurized exhaust gas. The combustor 14 directs the hot pressurized gas through a transition piece into a turbine nozzle (or “stage one nozzle”), and other stages of buckets and nozzles causing rotation of the turbine 16 . Rotation of the turbine 16 causes the shaft 18 to rotate, thereby compressing the air as it flows into the compressor 12 .
[0015] Referring to FIG. 2 , the turbine inlet assembly 22 is illustrated in greater detail. The turbine inlet assembly 22 includes an entry portion 30 for the airstream 24 , where the entry portion 30 typically comprises one or more weather hoods or louvers. The entry portion 30 provides a path for the airstream 24 to enter an inlet filter compartment 32 from ambient surroundings. In cooler operating environments, various anti-icing devices may be disposed proximate and/or downstream of the entry portion 30 to prevent ice formation and plugging within the turbine inlet assembly 22 . Additionally, optional cooling components may be employed to reduce the dry bulb temperature of the airstream 24 . An inlet duct 34 is configured to contain and route the airstream to an inlet plenum 36 . The inlet duct 34 comprises numerous sections that may vary in orientation and geometric configuration. For example, a first duct portion 38 is shown as having a relatively horizontal orientation prior to redirection through an elbow 40 to a second duct portion 42 having a relatively vertical orientation. The inlet plenum 36 is configured to provide a relatively turbulent-free region for immediate entry of the airstream 24 to the compressor 12 . The airstream 24 is subjected to yet another redirection during entry to the compressor 12 through the inlet plenum 36 . The inlet plenum 36 directs the airstream 24 into a compressor inlet bellmouth 46 .
[0016] Referring to FIG. 3 , in regions of redirection and/or variance in geometric configuration of the airstream 24 path, flow separation may occur, with a boundary layer forming proximate structural components of the turbine inlet assembly 22 . To reduce flow separation and associated pressure drop within the turbine inlet assembly 22 , a plasma actuator 44 is disposed within the turbine inlet assembly 22 . Although a single plasma actuator is described, it is to be appreciated that a plurality of such plasma actuators may be employed and is dictated by the application of use. The plasma actuator 44 may be disposed at any region of the turbine inlet assembly 22 that subjects the airstream 24 to a rapid change in orientation and/or geometric configuration. Regions proximate the elbow 40 , the inlet plenum 36 and the compressor inlet bellmouth 46 are examples of locations where disposal of the plasma actuator 44 may assist in reduction of flow separation exhibited at such regions. Although the previously mentioned regions are exemplary locations known to benefit from use of the plasma actuator 44 , it is to be understood that the plasma actuator 44 may be located anywhere within the turbine inlet assembly 22 .
[0017] The plasma actuator 44 controllably produces an electric field to manipulate a portion of the airstream 24 proximate an area typically associated with flow separation, including but not limited to an outer wall 48 ( FIG. 2 ) of the turbine inlet assembly 22 , the outer wall 48 defining and enclosing the path of the airstream 24 , or on a wall 50 of the inlet plenum 36 , for example. The plasma actuator 44 includes a first electrode 52 , a second electrode 54 and a dielectric material 56 having a first side 58 and a second side 60 , to which the first electrode 52 and the second electrode 54 are arranged in proximity to, respectively. The dielectric material 56 may be configured for conforming to a variety of geometric surfaces, including non-planar surfaces, as well as relatively planar surfaces. The first electrode 52 and the second electrode 54 are operably connected to an energy source 62 . Both the first electrode 52 and the second electrode 54 comprise relatively low-diameter wires flush-mounted on the wall 50 , for example, but as noted above the first electrode 52 and the second electrode 54 may be positioned at numerous locations within the turbine inlet assembly 22 . The energy source 62 provides alternating current (AC) or direct current (DC) power to the first electrode 52 and the second electrode 54 . Upon reaching a threshold value voltage, the airstream 24 ionizes in a region of the largest electric potential to form plasma. The plasma forms around one of the first electrode 52 and the second electrode 54 and spreads over an area tangential to the wall 50 , in the form of an electric field. The plasma produces a force on the airstream 24 , which in turn causes a change in the pressure distribution along whatever surface the plasma actuator 44 is disposed in proximity to. The change in pressure distribution generally reduces or substantially prevents flow separation when the plasma actuator 44 is energized by the energy source 62 .
[0018] Referring now to FIG. 4 , an inlet portion 70 of the compressor 12 is illustrated. The inlet portion 70 includes at least one strut 72 that provides structural support proximate an inlet casing 74 of the compressor 12 . Additionally, the inlet portion 70 includes at least one, but typically a plurality of, inlet guide vanes 76 that may have variable aerodynamic vane positions. The angle of the at least one inlet guide vanes 76 may vary based on different ranges of compressor flows (i.e., startup and various unit power output settings), thereby improving operating efficiency of the compressor 12 . For example, during extended turn down operation of the gas turbine system 10 , the angle of the inlet guide vanes 76 may be reduced. An increased chance of flow separation of a portion of the airstream 24 is present during such a configuration of the inlet guide vanes 76 , thereby creating flow disturbances in the inlet portion 70 of the compressor 12 . To reduce flow separation in regions proximate the strut 72 and/or the inlet guide vanes 76 , or more specifically an exterior surface 78 of the inlet guide vanes 76 , the plasma actuator 44 may be disposed proximate one or both component. The plasma actuator 44 has been described in detail above and further description is not necessary. As shown, the plasma actuator 44 , or a plurality of plasma actuators, may be disposed at various locations on the strut 72 and/or the inlet guide vanes 76 .
[0019] Accordingly, the flow profile of the airstream 24 in regions of the turbine inlet assembly 22 and the inlet portion 70 of the compressor 12 may be better controlled, while reducing fluctuations in the airstream 24 that occur due to upstream disturbances. The overall efficiency of the gas turbine system 10 is improved by use of the plasma actuator 44 , which requires a relatively low amount of power consumption with real-time control.
[0020] While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims. | A gas turbine system having a plasma actuator flow control arrangement including a compressor section for compressing an airstream, wherein the compressor section includes at least one inlet guide vane for controlling the airstream proximate an inlet portion of the compressor section. Also included is a turbine inlet assembly for ingesting the airstream to be routed to the compressor section. Further included is a plasma actuator disposed within at least one of the inlet portion of the compressor section and the turbine inlet assembly for controllably producing an electric field to manipulate a portion of the airstream. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a hinge for a mobile terminal, such as a mobile telephone, and to a novel type of hinge, which may be used for mobile terminals.
[0003] 2. Description of Prior Art
[0004] Presently, mobile terminals may be made as two-part terminals where the two parts are able to rotate in relation to each other from an inactive position to an active position. Some of these terminals have a snap opening function whereby the rotation to the active position is automatic upon activation of a button. However, due to the biasing, the active position and the inactive positions are the only positions maintainable. Thus, this brings about a problem when e.g. trying to position the terminal in a manner so that a display or the like may be visible.
[0005] It has been found that it is desirable to have, in a mobile terminal, a more freely selectable angle or rotation between such two parts.
SUMMARY OF THE INVENTION
[0006] Thus, in a first aspect, the invention relates to a mobile terminal having two parts connected to each other by a hinge, the hinge comprising:
[0007] a helical spring having a longitudinal axis, the spring comprising one or more wound strands of material, each strand having two ends,
[0008] a first hinge part extending into the helical spring, contacting an inner part of the helical spring at a first position or area along the longitudinal axis, and being connected to or attached to a first part of the two parts, and
[0009] a second hinge part contacting the one or more strands of the helical spring and being connected to or attached to a second part of the two parts,
[0010] the spring facilitating that:
[0011] rotation of the first hinge part in a first direction around the longitudinal axis and in relation to the second hinge part will provide a first, lower friction between the first hinge part and the helical spring, and
[0012] rotation of the first hinge part in a second direction, being opposite to the first direction, around the longitudinal axis and in relation to the second hinge part will provide a second, higher friction between the first hinge part and the helical spring
[0013] the terminal further comprising:
[0014] release means for increasing a diameter of the helical spring at the first position or area in order to reduce the second, higher friction between the first hinge part and the helical spring during rotation of the first hinge part in the second direction, the second, higher friction being reduced to a third friction, and
[0015] biasing means for providing a rotation of the first hinge part in the second direction when the release means are operated, the biasing means providing a force exceeding a force required to overcome the third friction but being lower than a force required to overcome the second friction.
[0016] In this context, it should be noted that the hinge may have other, more standard, hinge means, whereby the present helical spring assembly may mostly be used as a rotatable clutch of the hinge.
[0017] A standard helical spring is normally made of only a single strand or elongated piece of the material (typically a metal or another stiff material). However, springs are contemplated being formed by a number of strands, the windings of which are positioned, one after the other, along the longitudinal axis of the spring.
[0018] Also, the helical spring needs only be formed by part of the strand(s). The ends of the strand(s) need not be part of the helical spring. These ends may be used for different purposes, such as immobilization or actual movement.
[0019] The normal manner of providing a wrap spring clutch is to have the two hinged or clutched elements extend into the spring and thereby engage the inner part of the spring. However, it should be noted that the same effect may be obtained by reversing the operation and engaging the spring at an outer side thereof. Thus, in order to loosen the engagement, the spring is then not loosened (diameter increased) but tightened (diameter reduced).
[0020] In this context, the first hinge part would normally extend into the spring from one end thereof and engage the inner side of the spring (at least in the clutched operation) along a position and area from that end and a predetermined distance into the spring along the axis. However, the part needs not contact the spring at the end but may do so at any position thereof.
[0021] The first hinge part preferably has, at the part extending into the spring, an at least substantially circular cross section corresponding to an inner cross section of the spring. In that manner, contact inside the spring may be a contact along the inner circumference of the spring.
[0022] The contact of the second hinge part and the spring may be an attachment or a biasing, depending on which type of movement of the spring the second hinge part is to prevent or brake.
[0023] If both the first and second hinge parts extend into the spring, the first and second hinge parts engage or contact the spring at different positions or areas along the longitudinal axis of the spring. The first hinge part extends into the spring, but the second one may engage an outer surface thereof, an inner surface thereof, or actually a part of the strand(s) not being part of the actual helical shape of the spring. This will become clearer below.
[0024] It is clear that friction is a manner of keeping two elements in a predetermined position until a force is experienced large enough to overcome the friction, where after rotation is obtained.
[0025] The operation and direction of the biasing force results in that the biasing means is not able to actually rotate the parts until the release means of the hinge is operated, whereby the second friction is reduced to the third friction. It is seen that the release thus provides a snap/automatic movement of the pertaining parts of the terminal. However, the hinge provides, at the same time, a freely selected rotational position of the two parts in that the biasing or snap action is only provided when the release means is operated.
[0026] In one embodiment, the spring comprises a non-helical part at an end of each of the one or more strands, and the second hinge part contacts only the non-helical part. Thus, the second hinge part does not actually extend into the spring and/or engage the inner part thereof. In this embodiment, the contact between the second hinge part and the non-helical part of the spring may be an attachment. Preferably, the first hinge member contacts at least substantially a full inner surface of the spring and/or extends a full length of the helical part of the spring (in the direction of the axis).
[0027] In another embodiment, one end of each of the strand(s) of the spring is fixed in relation to the second hinge part and the release means is adapted to displace the other end(s) of the strand(s) from a first position to a second position. In this embodiment, the release means are preferably adapted to not be rotated in relation to the second hinge part in order to facilitate the design of the release mechanism.
[0028] It may be desired to actually ensure that an accidental operation of the release means does not bring about rotation. Thus, the terminal could further comprise locking means for maintaining the parts in a predetermined rotational angle even when the release means are operated.
[0029] One manner of obtaining this displacement is one wherein the release means comprises, for each hinge, a wedge-shaped element adapted to be translated and thereby displace the end(s).
[0030] Another manner is one wherein the release means comprises, for each hinge, a flexible element engaging the end(s), the end(s) being adapted to bias the flexible element into a first, deformed state when in the first position, and the release means comprising means for bringing the flexible element into a first, regular state and thereby bringing the end(s) into the second position. This may be obtained when the flexible element is hollow and wherein the means for bringing comprise a means adapted to be translated into the hollowness of the flexible element. These bringing means may be translatable into and out of the flexible element and may be biased in a direction out of the hollowness so as to ensure that the end returns to the first position and that engagement is obtained between the first hinge part and the spring.
[0031] A second aspect of the invention relates to a hinge or a clutch for facilitating rotational movement of a first hinge part in relation to a second hinge part and around a rotational axis of the hinge, the hinge comprising:
[0032] a helical spring having a longitudinal axis along the rotational axis, the spring comprising one or more wound strands of material, each strand having two ends and a part extending outside the helical spring,
[0033] the first hinge part extending into the helical spring, contacting an inner part of the helical spring at a first position or area along the longitudinal axis, and
[0034] a second hinge part being attached only to the extending parts of each of the one or more strands of the helical spring,
[0035] the spring facilitating that:
[0036] rotation of the first hinge part in a first direction around the longitudinal axis and in relation to the second hinge part will provide a first, lower friction between the first hinge part and the helical spring, and
[0037] rotation of the first hinge part in a second direction, being opposite to the first direction, around the longitudinal axis and in relation to the second hinge part will provide a second, higher friction between the first hinge part and the helical spring.
[0038] Thus, the second hinge part does not contact the spring inside the helical part thereof—or at least does not contact the spring in the helical part. Contacting the spring at an end of the strands, such as ends not forming part of the helical spring but extend away there from, may render the mass production of this hinge or clutch more controllable.
[0039] Naturally, this hinge preferably comprises release means for increasing a diameter of the helical spring at the first position or area in order to reduce the second, higher friction between the first hinge part and the helical spring during rotation of the first hinge part in the second direction, the second, higher friction being reduced to a third friction
[0040] Also, the hinge preferably further comprises biasing means for providing a rotation of the first hinge part in the second direction when the release means are operated, the biasing means providing a force exceeding a force required to overcome the third friction but being lower than a force required to overcome the second friction. In this situation, both the automatic rotation and the freely selectable position are possible.
[0041] In one embodiment, again, the release means comprises, for each hinge, a wedge-shaped element adapted to be translated and displace the end(s).
[0042] In another embodiment, the release means comprises, for each hinge, a flexible element engaging the end(s), the end(s) being adapted to bias the flexible element into a first, deformed state when in the first position, and the release means comprising means for bringing the flexible element into a first, regular state and thereby bringing the end(s) into the second position. This flexible element could be hollow and the means for bringing could then comprise a means adapted to be translated into the hollowness of the flexible element. Also, then the bringing means are preferably adapted to be translated into and out of the flexible element and are biased in a direction out of the hollowness.
[0043] A third aspect of the invention relates to a method of operating a mobile terminal according the first aspect of the invention, the method comprising:
[0044] operating the release means so as to have the biasing means rotate the first hinge part from an initial position in the second direction in relation to the second hinge means through a first angle to a second position,
[0045] disengaging the release means,
[0046] rotating the first hinge part in the second direction and through a second angle being smaller than the first angle to a third position, and
[0047] allowing the hinge to maintain the first hinge part in the third position.
[0048] Thus, using this method, the automatic opening and the then freely selectable position is obtained.
BRIEF DESCRIPTION OF THE DRAWING
[0049] The invention will be explained more fully below, by way of example, in connection with preferred embodiments and with reference to the drawing, in which:
[0050] [0050]FIG. 1 illustrates the parts of a clutch/hinge,
[0051] [0051]FIG. 2 illustrates the parts of FIG. 1 assembled to the hinge,
[0052] [0052]FIG. 3 illustrates a different embodiment of a hinge,
[0053] [0053]FIG. 4 is a cut-through view of yet an embodiment of a hinge,
[0054] [0054]FIG. 5, is a cut-through view of the hinge of FIG. 4 now also having a biasing spring,
[0055] [0055]FIG. 6 illustrates one manner of loosening the helical spring,
[0056] [0056]FIG. 7 illustrates another embodiment of a manner of loosening the helical spring,
[0057] [0057]FIG. 8 illustrates a system having two parts, a hinge as seen in FIG. 5 and a spring loosening means,
[0058] [0058]FIG. 9 illustrates three different positions or angles between a mobile telephone body and a movable part thereof, and
[0059] [0059]FIG. 10 illustrates an embodiment different from that of FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
[0060] [0060]FIG. 1 illustrates the basic elements of a known wrap-spring clutch/hinge. This hinge 10 comprises two rod members 12 and 14 and a helical spring 16 having an internal surface 17 and two strand ends 18 and 20 . The diameters of the rod members 12 and 14 are larger than the internal diameter of the spring 16 .
[0061] This hinge is assembled in FIG. 2 where the rod members touch inside the spring 16 . It is clear that if the end 18 is kept fixed in relation to the rod member 12 , rotation of the rod member 14 in the direction of the arrow will tighten the spring 16 and thus lock the two rod members 12 and 14 to each other so as to obtain maximum torque. In that manner, torsion or rotational energy is transferred from rod member 14 to rod member 12 . On the other hand, if the rod member 14 was rotated in the other direction (opposite to the arrow), this movement will only loosen the spring 16 , whereby almost no torque is transferred.
[0062] Also illustrated in FIG. 2 is a wedge 15 which may be used for moving the end 20 of the spring 16 . If the wedge is moved so as to lift (on the figure) the end 20 , the spring 16 will be “loosened” which means that the internal diameter thereof will increase so that the rod member 14 may now be moved in the direction of the fat arrow without tightening the spring 16 and transferring torque to the rod member 12 .
[0063] In that manner, rotation of the member 14 in the direction of the fat arrow, around the longitudinal axis A, without operating the release wedge 15 , a high friction is obtained due to the fact that the spring 16 will tighten. Rotation in the opposite direction of the member 14 will, on the other hand, incur a much lower friction due to the spring 16 loosening. Also, when operating the wedge 15 , a third, low friction is experienced when rotating the member 14 in the direction of the fat arrow.
[0064] In FIG. 3, a different embodiment is illustrated which also has the rod member 14 and the spring 16 with the ends 18 and 20 . However, the rod member 12 has been removed, and instead the element hitherto connected to the rod member 12 is attached to the end 18 . As described above, this embodiment has certain advantages to the embodiment where the rod members abut in the spring 16 . Preferably, the rod 14 now extends throughout the whole of the helical spring 16 .
[0065] [0065]FIG. 4 illustrates another embodiment of a hinge having the same function. This hinge also has a first rod member 12 , the second rod member 14 —now in the form of a tubular element extending over part of the rod member 12 . The spring 16 has the “unlocking end” 20 and the end 18 , which is now fixed to a fixed element.
[0066] In FIG. 5, the hinge of FIG. 4 has been added elements 30 (fixed to the rod member 12 and in which the end 18 is fixed) and 32 (fixed to rod member 14 ) as well as a locking element 42 preventing the spring 16 from moving into a space between the rods 12 and 14 and creating backlash etc. in the system. It is seen that instead of immobilizing the end 18 , the element 30 may be immobilized. Also, a biasing spring 44 is added having one end attached to the element 32 and the other (not illustrated) fixed to the rod member 12 . Thus, it is clear that the element 32 and rod member 14 may be rotated over the rod member 12 , this movement being biased by the biasing spring 44 .
[0067] In this respect, it is preferred that the fixed end 18 and the wedge 15 (see also FIGS. 6 and 7) exist in the same system—meaning that these elements are not rotatable (but may be translatable) in relation to the rod member 12 or element 30 . This will become clear from FIG. 8.
[0068] A number of choices exist when assembling the present hinge. Either the spring 16 is slightly opened before introducing the rods 12 and 14 (when the outer diameter of the rods is larger than the inner diameter of the spring) so as to obtain an engagement or friction there between in the un-operated situation (when the outer diameter of the rods is smaller than the inner diameter of the spring), so that operation may be a loosening of the spring 16 . Alternatively, it may be desired to actually bias the end 20 in the un-operated situation, so that operation may be a tightening of the spring 16 . In either way, it may be desired to bias the end 20 in the “tightening” direction in the un-operated situation.
[0069] [0069]FIGS. 6 and 7 illustrate different manners of actually loosening the spring 16 . In FIG. 6, the wedge 15 is illustrated together with two different positions of the end 20 of the spring 16 . Depending on the distance between the wedge 15 and the helical part of the spring 16 , this movement of the end 20 will provide more or less loosening of the spring 16 .
[0070] In FIG. 6, the wedge 15 is supplemented by another element 15 ′ forming, together with the wedge 15 a track in which the end 20 travels. This track may be used for actually biasing the end 20 in the tightening direction. This operation is seen as the un-biased position of the end 20 is illustrated by a dotted end 20 ′. Thus, moving the end 20 upwards will loosen the spring, and in the un-operated position, the end 20 is that depicted at the lower position, which is lower than the unbiased position 20 ′.
[0071] Another manner is seen in FIG. 7, where the end 20 rests against a flexible element 24 inside which an elongated, stiff element 26 may slide. It is seen that the end 20 , in fact, is biased against the element 24 in such a manner that when the element 26 is retracted, the end 20 will deform the element 24 and thereby tighten the spring 16 .
[0072] The element 26 is biased away from and out of the element 24 by a biasing spring 27 , and the elements 26 , 24 and 20 are controlled by holding means 22 .
[0073] Returning to FIG. 2, it is clear that loosening of the spring 16 may be performed by moving the spring end 20 in a number of ways, such as in the direction of the fat arrow or in a direction along the end 20 toward the spring 16 .
[0074] [0074]FIG. 8 illustrates a two-part system having a first part 30 connected via a hinge 50 to a second part 32 . The reference numerals from FIG. 5 have been omitted in order to retain the clarity of the figure.
[0075] The actual “direction” of the hinge (that is, the high friction and low friction rotation directions and the directions of the biasing springs) will depend on the actual embodiment. Two embodiments are described in relation to FIGS. 9 and 10.
[0076] The part 30 of the system of FIG. 8 has a spring loosening mechanism having a push button 29 connected to a loosening mechanism 36 , such as the wedge 15 , and being biased by a biasing spring 38 engaging a fixed element 40 in the part 30 .
[0077] The first part 30 is further rotationally attached to the second part 32 by an element 42 . This is only to stabilize the rotation of the parts.
[0078] In FIG. 9, the mobile telephone 28 has the first and second parts 30 and 32 as well as a hinge or clutch illustrated at 33 , a release mechanism 34 for the hinge 33 .
[0079] [0079]FIG. 9 illustrates three different angles between the first part 30 and the second part 32 and therefore a specific use of the mobile telephone 28 .
[0080] In normal non-operative use, the mobile telephone 28 will be stored as illustrated in the left-most drawing where the first and second parts 30 and 32 are adjacent to each other. In the present embodiment, the second part 32 has a microphone 41 protected in the position in the left-most illustration. The telephone 28 also has a speaker 39 in the first part 30 .
[0081] The hinge 33 is provided in the telephone 28 so that the rod member 14 is attached to the second part 32 and so that the rod member 12 and/or the end 18 is attached to the first part 30 . Also, a release mechanism as that illustrated by the wedge 15 is operatively connected to the button 34 . The spring 16 is directed so that the rotation in the direction of the fat arrow (see FIGS. 2 or 3 ) will take place when rotating the second part 32 as illustrated by the fat arrow in the middle illustration of FIG. 9.
[0082] In order to operate the telephone 28 , such as when wishing to make a telephone call, the second part 32 is rotated as illustrated by the fat arrow in the middle illustration. In this manner, the microphone becomes accessible. This activation is obtained by releasing the release mechanism 34 , which loosens the spring 16 and allows the biasing means to overcome the third friction and rotate the second part 32 to e.g. a stopping position as that illustrated in the middle illustration. This position may be pre-defined as that providing the optimal position for use when making a telephone call. This position may also be one where the second part 32 is rotated further in the direction of the fat arrow.
[0083] Having obtained that position of the second part 32 , the release button 34 is disengaged.
[0084] Having e.g. made the telephone call, it may be desired to have a different angle on the second part 32 such as in order for the telephone 28 to be able to stand up and present a display 31 thereof to the user. Thus, the second part 32 may be rotated in a direction opposite to that illustrated by the fat arrow. Due to the friction of the hinge 33 —as well as the operation of the biasing means, the second part 32 will be substantially fixed and will be able to e.g. hold the telephone at the desired angle or in the desired position.
[0085] The telephone 28 may also have a locking means 37 for maintaining the second part 32 in the closed position even if the release button 34 is operated.
[0086] Naturally, the hinge may be reversed to that a snap closing is achieved by operating the button 34 . Thus, the parts are rotated by hand (in the low friction direction of the hinge), and are maintained in that angular position until the button is operated, where after the biasing spring will close the parts again.
[0087] Finally, in FIG. 10, a further embodiment is seen at an angle from the back (above) and directly from the front (below). This embodiment 51 may also be a telephone or a palm computer having two parts 52 and 54 interconnected by a hinge (not illustrated) and having a release button 56 to be used as described above.
[0088] Thus, operation may be as described above: operation of the release button 56 may make the biasing means open the telephone/computer 51 for operation. Releasing the release button will make further rotation in the opening direction (the fat arrow) difficult (due to the high friction), but rotation in the opposite direction (the closing direction) will be easy.
[0089] Again, any desired angle between the parts may be obtained at the same time as a snap opening (the operation of the biasing means) may be obtained.
[0090] The present embodiments have centred on mobile telephones. However, the same functionality may be obtained in any type of element where a combination of an automatic opening of a device is desired combined with a subsequent, freely selected positioning of the elements. This may be in hand-held or palm-size electronic systems, portable computers or toys of any type. | A mobile terminal, such as a mobile telephone, has a hinge with a helical spring and which provides both snap opening or automatic opening upon activation of a release means as well as a freely selectable angular position between the rotating parts of the terminal. Also, a new type of spring hinges or clutches are described for use in e.g. this type of terminal. | 4 |
FIELD OF THE INVENTION
This invention relates generally to asynchronous cache system devices and, more specifically, to a combined asynchronous cache system and automatic clock tuning device and method therefor which provides a clock tuning device that automatically delays a System Clock (SCLK) signal to produce a Delayed Clock (DCLK) signal that defines the time at which a logic level transition of a Write Enable (WE) signal takes place in order to ensure that a Central Processing Unit (CPU) address/data hold time is accomplished without adding unnecessary wait states.
DESCRIPTION OF THE PRIOR ART
The problem to be solved pertains to an asynchronous cache sub-system. In particular, it is possible for an address/data hold time violation to occur relative to a WE signal transition from a low to a high state with an asynchronous cache data/tag Static Random Access Memory (SRAM) device. In short, this means that if a data transfer is prematurely terminated, then when the WE signal executes a transition from a low to a high state, the incorrect data is latched into the SRAM device. In X86 CPU based systems, the address and the data signals turn off synchronous with the transition of the SCLK signal from a low state to a high state. Since the WE signal is a controlled pulse width, it is desirable that the WE signal also be synchronous. Unfortunately, when the WE signal is synchronized to the low state to high state transition of the SCLK signal, the possibility exists that the output delay of the WE signal may be longer than the address/data hold time delay of the CPU. Consequently, in this case, spurious data is written to the cache SRAM devices and the cache sub-system fails operate properly.
One possible solution to the aforementioned problem is to clock the WE signal off of the negative edges of the SCLK signal, thereby ensuring that the output rise delay time of the WE signal occurs before the next rising edge of the SCLK signal. This approach creates a performance penalty of one CPU clock (1 SCLK) due to the delay of the activation of the WE signal by 1/2 SCLK.
Another possible solution to this problem might be to use a synchronous data/tag SRAM device. These devices include an input for the system clock which samples the address/data on the rising edges of the SCLK signal when the WE signal is held active. The inclusion of the SCLK signal input to these synchronous data/tag SRAM devices effectively removes the hold time problem associated with the use of asynchronous SRAM devices. However, these synchronous SRAM devices are significantly more expensive than their asynchronous SRAM device counterparts. Therefore, a need existed to provide a cost-effective, asynchronous cache sub-system without creating a performance penalty by adding an extra SCLK period in order to ensure CPU address/data hold time during cache data or tag SRAM device updates.
SUMMARY OF THE INVENTION
In accordance with one embodiment of this invention, it is an object of this invention to provide an automatic clock tuning device.
It is another object of this invention to provide a combined asynchronous cache system and automatic clock tuning device and method therefor.
It is a further object of this invention to provide a combined asynchronous cache system and automatic clock tuning device that ensures that a CPU address/data hold time is accomplished without adding unnecessary wait states.
It is still another object of this invention to provide a combined asynchronous cache system and automatic clock tuning device that uses feedback of an actual system signal in order to include the system impedance.
It is yet another object of this invention to provide a combined asynchronous cache system and automatic clock tuning device which produces a delay unit that has a maximum value that is less than or equal to a processor's maximum hold time for address and data relative to SCLK.
It is a further object of this invention to provide a combined asynchronous cache system and automatic clock tuning device that automatically disables the tuning process of DCLK upon reaching a pre-defined condition in order to conserve energy.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with one embodiment of this invention, a combination asynchronous cache system and automatic clock tuning device is disclosed comprising, in combination, an asynchronous cache system and an automatic clock tuning device coupled to the asynchronous cache system and comprising, in combination, counter means for counting the number of occurrences that an INCREMENT signal input is sampled in a desired state and for producing an output count signal corresponding to the number of occurrences, variable delay means coupled to a System Clock (SCLK) signal and to the output count signal for producing a Delayed Clock (DCLK) signal where the SCLK signal is delayed by the variable delay means by an amount proportional to the output count signal to produce the DCLK signal, output means coupled to the DCLK signal for delivering a Write Enable (WE) signal to an external system load and to a portion of the automatic clock tuning device, comparing means coupled to both the WE signal and to the SCLK signal for outputting the INCREMENT signal when the comparing means samples an occurrence of a rising edge of the WE signal prior to an occurrence of a rising edge of the SCLK signal, an OR-Gate coupled to the comparing means, feedback Flip-Flop means having a data input junction coupled to the INCREMENT signal for providing an output for driving at least one input junction of the OR-Gate, first D-type Flip-Flop means having a data input junction coupled to an output of the OR-Gate for providing data input to the output means, second D-type Flip-Flop means having a data input junction coupled to the output from the first D-type Flip-Flop means for providing the SCLK signal to the comparing means, pulse generator means coupled to a RESET signal input and the SCLK signal input for generating an initial START PULSE signal output coupled to an input junction of the OR-Gate, NOR-Gate means having at least a first active low input junction coupled to the RESET signal for clearing data content of each of the first D-type Flip-Flop means, the second D-type FlipFlop means, and the comparing means, and maximum count detection means coupled to the counter means and to a second active low input junction of the NOR-Gate means for clearing data content of each of the first D-type Flip-Flop means, the second D-type Flip-Flop means, and the comparing means in response to the maximum count detection means reaching a maximum count condition.
In accordance with another embodiment of this invention, a method of operating a combination asynchronous cache system and automatic-clock tuning device is provided comprising the steps of providing an asynchronous cache system and providing an automatic clock tuning device coupled to the asynchronous cache system and comprising the steps of providing counter means for counting the number of occurrences that an INCREMENT signal input is sampled in a desired state and for producing an output count signal corresponding to the number of occurrences, providing variable delay means coupled to a System Clock (SCLK) signal and to the output count signal for producing a Delayed Clock (DCLK) signal where the SCLK signal is delayed by the variable delay means by an amount proportional to the output count signal to produce the DCLK signal, providing output means coupled to the DCLK signal for delivering a Write Enable (WE) signal to an external system load and to a portion of the automatic clock tuning device, providing comparing means coupled to both the WE signal and to the SCLK signal for outputting the INCREMENT signal when the comparing means samples an occurrence of a rising edge of the WE signal prior to an occurrence of a rising edge of the SCLK signal, providing an OR-Gate coupled to the comparing means, providing feedback Flip-Flop means having a data input junction coupled to the INCREMENT signal for providing an output for driving at least one input junction of the OR-Gate, providing first D-type Flip-Flop means having a data input junction coupled to an output of the OR-Gate for providing data input to the output means, providing second D-type Flip-Flop means having a data input junction coupled to the output from the first D-type Flip-Flop means for providing the SCLK signal to the comparing means, providing pulse generator means coupled to a RESET signal input and the SCLK signal input for generating an initial START PULSE signal output coupled to an input junction of the ORGate, providing NOR-Gate means having at least a first active low input junction coupled to the RESET signal for clearing data content of each of the first D-type Flip-Flop means, the second D-type Flip-Flop means, and the comparing means, and providing maximum count detection means coupled to the counter means and to a second active low input junction of the NOR-Gate means for clearing data content of each of the first D-type Flip-Flop means, the second D-type Flip-Flop means, and the comparing means in response to the maximum count detection means reaching a maximum count condition.
In accordance with yet another embodiment of this invention, a combination asynchronous cache system and automatic clock tuning device is disclosed comprising, in combination, an asynchronous cache system and an automatic clock tuning device coupled to the asynchronous cache system and comprising, in combination, a first closed loop means for generating an output signal for use by the asynchronous cache system and having at least a counter device, a variable delay device, an output portion, and a comparator, and a second closed loop means for providing a data signal to a portion of the first closed loop means and having at least an OR-Gate and a plurality of Flip-Flops where the second closed loop means is coupled to the comparator. In addition, this device further includes means for clearing data contents of the plurality of Flip-Flops and the comparator. Furthermore, this automatic clock tuning device includes pulse generator means coupled to a RESET signal input and a SCLK signal input for generating an initial START PULSE signal output coupled to an input junction of the OR-Gate. Also, this device includes maximum count detection means coupled to a portion of each of the first closed loop means and the second closed loop means for clearing data content of a portion of each of the first closed loop means and the second closed loop means in response to the maximum count detection means reaching a maximum count condition.
The forgoing and other objects, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiments of the invention, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified block diagram of the automatic clock tuning device attached to an external system load.
FIG. 2 is a timing diagram showing a prior art approach to executing a cache write cycle.
FIG. 3 is a simplified timing diagram showing the automatic clock tuning device executing a cache write cycle.
FIG. 4 is a simplified timing diagram showing the start up operation of the automatic clock tuning device.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a simplified block diagram of the automatic clock tuning device is shown and is generally designated by reference number 10. Note that in this embodiment the automatic clock tuning device 10 is part of a controller for a cache device which is not shown here for the sake of simplicity. In addition, note that although the device 10 is intended for use as part of a cache controller, if desired, this device 10 could be integrated into other systems that require the functions performed by the device 10. A System Clock (SCLK) signal is coupled to a synchronous counter 12, a variable delay tree 14, a pulse generator 32, a first D-Type Flip-Flop 28 corresponding to register 2, a second D-Type Flip-Flop 30 corresponding to register 3, a comparing device such as a comparator 22, and a D-Type Flip-Flop 24. Note that the D-Type Flip-Flop 24 is also called the feedback Flip-Flop 24. An active low RESET signal, hereinafter simply referred to as the RESET signal, is coupled to the pulse generator or pulse generator on reset 32, a NOR-Gate 34, and the feedback Flip-Flop 24.
Again, in reference to FIG. 1, the synchronous counter 12 has an input junction coupled to an INCREMENT signal coming from the comparing device 22. The synchronous counter 12 samples the INCREMENT signal and counts the number of occurrences of a specific logic level of this signal and then outputs a signal corresponding to the count. In addition, the synchronous counter 12 has a pre-selected maximum level up to which it can count. The variable delay tree 14 is coupled to the output count signal from the synchronous counter 12 in order to select a delay which is proportional to the output count signal. The range of the synchronous counter 12 is large enough to ensure that the DCLK signal is capable of being shifted at least 1/2 period of the SCLK signal regardless of any conceivable process, temperature, and/or operating voltage conditions that may result in a minimum unit delay from the variable delay tree 14. The variable delay tree 14 applies this selected delay to the SCLK input to create a Delayed Clock (DCLK) signal output. The DCLK signal is applied to an active low input clock junction for the register 1 or the D-Type Flip-Flop 16. The data input junction of the D-Type Flip-Flop 16 is coupled to the output junction of the first D-Type Flip-Flop 28. The active low output junction of Flip-Flop 16 is coupled to an output driver 18 which delivers a Write Enable (WE) signal to an external system load which is modeled as a capacitor C and an inductor L. Such an external system might be representative of cache memory devices such as Static Random Access Memory (SRAM) devices. The inherent impedance of the external system is reflected in the signal returned to the automatic clock tuning device 10 via the input driver 20. The input driver 20 and the output driver 18 comprise a bidirectional I/O driver and, in addition, this bidirectional I/O driver together with the Flip-Flop 16 comprise an output stage for the device 10. Note that the output driver 18 is coupled to an OUTPUT ENABLE signal to enable this driver 18. The output of the input driver 20 is coupled to the comparing device 22. In addition, the comparing device 22 is coupled to the output signal from the second D-Type Flip-Flop 30. This signal represents the SCLK signal so that the comparing device 22 compares the rising edge of the WE signal to the rising edge of the SCLK signal. If the rising edge of the WE signal occurs prior to the rising edge of the SCLK signal, then the comparing device 22 outputs an INCREMENT pulse to both the synchronous counter 12 and the data input of the feedback Flip-Flop 24. The output of the feedback Flip-Flop 24 is coupled to an input junction of the OR-Gate 26 and the output of the OR-Gate 26 is coupled to the data input for the first D-Type Flip-Flop 28. The output of the first D-Type Flip-Flop 28 is coupled to both the data input for the D-Type Flip-Flop 16 and the data input for the second D-Type Flip-Flop 30.
The output of the pulse generator 32 is coupled to an input junction of the OR-Gate 26 in order to generate an initial START PULSE signal upon a computer system start up. The RESET signal is coupled to an active low input junction of the NOR-Gate 34 so that upon system start up, the data content of each of the first D-Type Flip-Flop 28, the second D-Type Flip-Flop 30, and the comparing device 22 are cleared. Also, note that the RESET signal is directly connected to an active low input junction to clear the data content of the feedback Flip-Flop 24 upon system start up. The maximum count detect device 36 is coupled to the output count signal coming from the synchronous counter 12. At a pre-selected maximum count, the maximum count detect device 36 sends a signal to an active low input junction of the NOR-Gate 34 in order to clear the data content of each of the first D-Type Flip-Flop 28, the second D-Type Flip-Flop 30, and the comparing device 22, thereby reducing the amount of energy consumed by the device 10.
OPERATION
The automatic clock tuning device 10 works by creating a positive START PULSE after system start up. This pulse is then sampled by two separate registers, namely registers 1 and 2. Register i clocks the pulse on the falling edge of the DCLK signal that is initially synchronous to the SCLK signal. Resister 1 then inverts the output signal. Register 2 clocks the initial pulse on the rising edge of the SCLK signal. The negative pulse generated by register 1 is directed off of the device 10 chip to an externally coupled cache data or tag SRAM device's WE signal junction, thereby seeing the actual system impedance. This same signal is fed back via the bidirectional I/O device 18 and 20. The. output pulse of register 2 is sampled once more with the rising edge of the SCLK signal by register 3. The output of register 3 is used to enable a comparison of the rising edge of the SCLK signal to the rising edge of the WE signal. If the rising edge of the WE signal occurs prior to the rising edge of the SCLK signal, an INCREMENT pulse is output from the comparing device 22. This INCREMENT pulse is counted by the synchronous counter 12 whose output is used by the variable delay tree 14 to add one unit delay to the DCLK signal. The INCREMENT pulse is also fed back to the input of the feedback Flip-Flop 24 whose output is coupled to the data input of register 2, and subsequently, to the data input of register 1. This process is repeated until the rising edge of the WE signal occurs at approximately the same time as the rising edge of the SCLK signal and, at this time, no further INCREMENT pulses are generated.
The following signal descriptions should help to facilitate a better understanding of the subsequent timing diagrams:
SCLK: SYSTEM CLOCK is used to synchronize a CPU and a cache controller.
CYC -- START: CYCLE START is issued by the CPU to indicate the beginning of the CPU bus cycle.
READYO: READY OUT is driven active low by the cache controller to indicate that a data transfer has been completed.
DATA: WRITE DATA is driven by the CPU when it is attempting to write data to memory.
DCLK: DELAYED CLOCK is driven by the automatic clock tuning device 10 of a cache controller and this signal is used to synchronize the WE signal.
WE: WRITE ENABLE is an active low signal driven by the automatic clock tuning device 10 of a cache controller to the cache memory. A rising edge of the WE signal latches data into memory.
START -- PULSE: START PULSE is driven by the pulse generator 32 on system start up.
REG1 -- QB(WE): REGISTER1OUTPUTfWE) is the WE signal output of register 1.
REG2 -- Q: REGISTER2 OUTPUT is the output of register 2.
REG3 -- Q: REGISTER3 OUTPUT is the output of register 3.
INCREMENT: INCREMENT is driven by the comparing device 22 when the rising edge of the WE signal occurs prior to the sampling of the rising edge of the SCLK signal.
Referring to FIG. 2, the CPU signifies the beginning of a CPU bus cycle by driving the CYC -- START signal high at 1. The WE signal is shown going low and then high between point 6 and 7, and, in addition, the WE signal is shown in phantom making a similar logic transition between the falling edges of SCLK at 5 and 6 and between the rising edges of SCLK at 2 and 3. Note that the WE signal transition requires one full period of the SCLK signal. The READYO signal is shown going logic low and then logic high at points 3 and 4, respectively, and a similar transition is shown in phantom between points 2 and 3. The write cycle, which is defined as the time between the CYC -- START signal going high and the READYO signal being sampled low, requires three full periods of the SCLK signal, namely from points 1 to 4. The write cycle could be shortened if the WE signal was clocked off of the SCLK signal at points 5 and 6 or points 2 and 3. However, if the WE signal was clocked off at points 5 and 6, the data setup time to WE transitioning high would be violated, and the write cycle would be unsuccessful. Setup time is defined as the time from which data transmission begins until the time that the WE signal goes high to latch in the data to memory. There is a minimum allowable setup time and by clocking WE off of points 5 and 6, WE goes high too soon to allow the appropriate setup time. If the WE signal was clocked off of points 2 and 3 thereby allowing the READYO signal to be moved left to be clocked off of points 2 and 3, one clock cycle would be saved, however, the CPU would stop driving the DATA signal on edge 3, and the data hold time relative to the WE signal low to high transition would be violated. In other words, since the data ceases at point 3, when the WE signal goes high just to the right of point 3, the incorrect data is latched into memory.
Referring to FIG. 3, with the introduction of the new delayed clock signal DCLK from the automatic clock tuning device 10, the WE signal is clocked high at some time after the SCLK edge at point 6 and before the SCLK edge at point 7 to create several advantages. The entire write cycle would require only two SCLK periods, namely from point 1 to point 3. The required data setup time is met. In addition, note that at the time the WE signal makes the low to high transition, the data signal is still present so that the hold time requirement is successfully accomplished.
Referring to FIG. 4, a timing diagram shows the start up sequence for the automatic clock tuning device 10. Of particular interest, reference point 1 shows the DCLK signal going low to drive the WE signal high. Also, note that at this point the SCLK signal and the DCLK signal are in phase. In addition, at reference point 1, the rising edge of the WE signal lags the rising edge of the SCLK signal located at the 200ns point. This lagging condition of the WE signal relative to the SCLK signal is detected by the comparing device 22, and consequently, one notices that the DCLK signal begins to shift to the right, thereby creating a noticeable phase difference between DCLK and SCLK at reference point 2. At reference point 3, the falling edge of the DCLK signal triggers the rising edge of the WE signal, and note that the WE signal has moved farther to the right or closer to the rising edge of the SCLK signal at the 400ns point. At reference point 4, note again that the DCLK signal has been phase shifted farther to the right. At reference point 5, the falling edge of the DCLK signal causes the rising transition of the WE signal. Both the DCLK signal and the WE signal have clearly been shifted to the right when one compares their positions relative to the SCLK signal at reference point 1 as compared to their positions at reference point 5. Also, one observes that the rising edge of the WE signal has occurred at nearly the same time as the SCLK rising edge at reference point 5.
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention. For example, the period for the SCLK signal could be changed to 30ns or any other desirable value. In addition, the device 10 defines an INCREMENT signal which results in shifting the DCLK and the WE signals to the right, however, if desired, one could implement a means for shifting these or other signals to the left with respect to a time axis. | A combination asynchronous cache system and automatic clock tuning device is disclosed in which the automatic clock tuning device includes at least a pulse generator, a counter, a unit delay tree, a comparing device, and a feedback path. A portion of the feedback path delivers a signal of interest off of the device chip in order that the signal experience the effect of the actual system impedance prior to being returned to the device chip for further manipulation of the signal. A major concept of the automatic clock tuning device is to enable a cache data/tag Write Enable (WE) signal to be clocked off of the falling edge of a delayed version of the System Clock (SCLK). This Delayed Clock (DCLK) signal is automatically delayed by a pre-selected amount each time that the rising edge of the WE signal occurs earlier than the rising edge of the SCLK signal. As long as the rising edge of the WE signal occurs slightly before or at the same time as the rising edge of the SCLK signal the CPU address/data hold time is successfully accomplished without adding superfluous wait states. | 8 |
This is a continuation of application Ser. No. 573,686 filed Jan. 25, 1984 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to systems for handling canisters carrying product for treatment or processing, for example, systems for handling canisters in which monomer is converted to flocculant polymer as by exposure to ionizing radiation.
2. Description of the Prior Art
In the prior art, canisters lined with plastic bags receive a liquid monomer and are carried into a radiation chamber where the monomer is subjected to ionizing radiation to polymerize the monomer and form a solid polymer log with a rubber-like consistency which can be subsequently dissolved and used for various purposes. The canisters containing the polymerized material are removed from the radiation chamber and stored after which the polymerized material with the liner bag is then dumped from the canister for packing or further processing, and the canisters are cycled back for reuse as containers for receiving and processing additional monomer.
The canisters, after filling with the monomer, are transported in vertical carriers or racks which have rollers attached to the upper ends and supporting the carriers on overhead rails so that the carriers may be pushed to various processing stations. The prior art canisters are generally vertically oriented cylindrical plastic containers with an open top, and the carriers include a pair of vertically-extending horizontally arcuate members having vertically-spaced disc-like shelves attached therebetween with one side being open for receiving the containers on the shelves. A spring biased chain is secured over the open side of the carrier to retain the containers therein and to prevent their falling from the carrier during processing. After polymerization, the containers are removed from the carrier and the polymerized material dumped by manually inverting the containers.
The prior art canister handling methods are relatively costly in requiring manpower to lift and invert each canister to dump the polyermized material from the canisters. Also, the manual effort required to remove the logs of polymerized material often resulted in physiological stress causing higher than normal rates of sick leave. The spring biased chains holding the prior art canisters in the carriers are subject to breaking and to catching on objects or clothing while the carriers are being handled or rotated.
SUMMARY OF THE INVENTION
In a first aspect, the present invention is summarized in a canister handling system including a structure rotatable about a horizontal axis and supporting a plurality of holders for gripping the containers in a circular arrangement tangentially on the periphery of the carrier wherein the holders are indexed through a loading station where the canisters are received upright by the holders, a content unloading station where the canisters are partially inverted to gravity unload the contents of the canisters, and a canister unloading station where the canisters are unloaded from the holders.
In a second aspect of the invention, a carrier and canister arrangement for handling a material includes a canister having outside vertical rib means which protrudes sufficiently so that the canister, after insertion, can be rotated in the carrier to a position where the ribs interlock with the arcuate side walls of the carrier to retain the canisters within the carrier.
An object of the invention is to substantially reduce the amount of manual effort required to handle canisters.
Another object of the invention is to construct a canister handling system which is relatively inexpensive and efficient.
One advantage of the invention is that the productivity of canister processing operation is increased with a decrease in the number of operators required.
Other objects, advantages and features of the invention will be apparent from the following description of the preferred embodiment taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view, taken from the right side, of a canister handling system in accordance with the invention.
FIG. 2 is a perspective view of a canister utilized in the invention.
FIG. 3 is a cross-section view of a carrier and canister illustrating the loading of the canister into the carrier.
FIG. 4 is a view similar to FIG. 3 but showing the canister secured within the carrier.
FIG. 5 is a front elevation view, with portions broken away, of a carrier elevator mechanism in the system of FIG. 1.
FIG. 6 is a horizontal section view of the system of FIG. 1 with various portions broken away, portions sectioned at different levels, and portions revolved to the horizontal from a non-horizontal plane.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One embodiment of a canister handling system as shown in FIG. 1, includes canisters 10 supported in vertically-extending carriers indicated generally at 12, an elevator mechanism indicated generally at 14 for raising and lowering a train of the carriers 12, and an unloading mechanism indicated generally at 16 for receiving the containers 10 and dumping their contents onto a conveyor 20 and for dropping the emptied canisters 10 onto a second conveyer 22. The canisters 10 and carriers 12 are particularly designed to carry a material, such as a liquid monomer, through a polymerization process, such as exposure to ionizing radiation in a shielded chamber forming the monomer into a solid polymer gel, but the present canister handling system can be utilized in the treating or handling of any suitable material which can be handled by a canister arrangement. The canister dumping mechanism 16 rotates the canisters 10 to a partially inverted position where the contents are gravity discharged onto the conveyer 20 which leads to a subsequent processing station such as a packing station for packing the discharged material suitable for shipment. The emptied canisters are deposited on the conveyer 22 which carries the canister to a station, such as a cleaning station, in the reuse of the canisters.
As shown in FIG. 2, each of the canisters 10 has a vertically-extending cylindrical or tubular wall which is closed at the bottom and open at the top. A horizontal ring-like rib 30 extends around the outer surface of the wall at a height equal to approximately one-third the total height above the bottom of the canister. One or more vertical ribs, such as four equally spaced vertical ribs 32, extend on the outer surface of the canister 10 above the rib 30 while similar shorter sections of ribs 34 aligned with the ribs 32 extend on the outer surface of the canister below the horizontal rib 30. The horizontal rib 30 is particularly designed to cooperate with clamping arms and the unloading apparatus of FIG. 1 to prevent the canister from sliding from the unloading apparatus when the canister is inverted to unload the contents. The bottom ends of the vertical ribs 32 are spaced above the horizontal rib 30 sufficiently to leave rib-free sections 36 of the outer cylindrical surface of the canister 10 suitable for being engaged by the clamps. The canister 10 and its ribs 30 and 32 are formed from a suitable material, such as integrally molded plastic which is not affected by the environment, in which the canister is utilized.
As shown in FIGS. 1 and 5, each of the carriers 12 has an upper double roller 40 rotatably mounted on the top of a header 42 for movably supporting the carrier on an inverted-T rail system 44. A pair of vertical wall members 46 and 48 extend downward from opposite sides of the header 42 and support spaced horizontal circular discs 50 forming shelves for supporting a plurality, for example four, canisters 10 in a vertically-stacked relationship. As shown in FIGS. 3 and 4, the horizontal cross-sections of the members 46 and 48 are arcuate and define sectors on opposite sides of the discs 50 with an inside diameter slightly greater than the diameter of the outside surface of the ribs 30, 32 and 34, to form partial side walls which with the shelves 50 define compartments in the carriers 12 for receiving the canisters 10. The wall members 46 and 48 leave a narrower vertical rear opening 51 and a wider front opening 52 which extends for an angle less than 180° of the discs 50. The width of the opening 52 defined by the front edges of the members 46 and 48 is selected to be less than the diameter of the outside surfaces of the ribs 32 and 34, but greater than the outside surface of the canister 10 so that the canister 10 can be inserted through the opening 52 when oriented as illustrated in FIG. 3 and is retained within the walls by the ribs 32 and 34 when rotated to the orientation shown in FIG. 4. Notches 54, see FIG. 1, are formed in the forward edges of the members 46 and 48 for passing the rib 30 during insertion and removal of the canister 10. Where pluralities of the ribs 32 and 34 are formed on the canisters 10, at least one pair of spaces must be left between ribs on opposite sides of the container for permitting the insertion as shown in FIG. 3. The employment of the vertical ribs 32 and 34 in combination with the particularly shaped vertical wall members 46 and 48 of the carriers enables the securement of the containers within the carriers without the need for chains or other fastening devices to ensure that the canisters do not fall from the carriers during handling and processing.
As shown in FIG. 5, a plurality of the carriers 12, such as four of the carriers, are joined into a train by a bar 56 which, for the example of the four-carrier train, is hinged at 58 to permit the train to negotiate curves. Bumpers 60 are attached to leading and trailing edges of the bar 56 for engaging bumpers of bars of succeeding and proceeding trains so that a plurality of trains may be advanced by pushing the trailing train along the rail 44.
The elevator 14 includes a vertically-slidable frame 70, FIGS. 1, 5 and 6, which is raised and lowered by an electrical motor-driven winch 72. Guides 74 with U-shaped horizontal cross-sections are mounted on the frames 70 and have low friction bushing material engaging vertical rails 76 mounted on stationary frame members 78 for guiding the frame 70 in upward and downward sliding movement. A section 80 of the rail system 44 is mounted by brackets 82 on the upper portion of the frame 70 for receiving one train of the carriers 12. The rail section 80 is beveled at its opposite ends so as to engage the stationary sections of the rail system 44 on its opposite ends when in a lowered position in order to ensure accurate positioning of the rail section 80.
A pivotal gravity biased stop 83 is mounted on the rail system 44 in front of the entrance end of the rail section 80 for engaging the rollers 40 to prevent passing of a train of carriers 12 past the stop 83 when the rail section 80 is raised. A pin 84 mounted on rail section 80 engages an arm 85 extending from the stop 83 when the rail section 80 is in the lowered position as shown in FIG. 5 to raise the stop 83 and permit the carriers to be loaded onto the rail section 80. Gravity biased pivotal stops 86 and 87 are mounted on the rail section 80 for retaining the train of carriers 12 thereon. An arm 88 may be manually rotated to release the end stop 87 to permit the train of carriers 12 to be unloaded. A similar gravity biased pivotal stop 89 is mounted on the rail system 44 at the exit end of the section 80 for preventing return of the carriers 12 onto the section 80 or into the space vacated when the section 80 is raised.
Push button switches 90 and 92 are provided for operating a winch control circuit 93 to raise and lower, respectively, the elevator 14. A microswitch 94 connected to the circuit 93 and suitably mounted on the stationary frame 78 is positioned for being engaged by pins 96 on the movable frame 70 for stopping upward movement of the elevator at positions for loading rows of the canisters 10 into the unloader mechanism 16. Upper and lower microswitches 98 and 100 are connected to the circuit 93 and are positioned to prevent excessive movement of the elevator beyond upper and lower limits.
The unloader mechanism 16, as illustrated in FIGS. 1 and 6, has five rows, including four holders each, for receiving and releasably gripping the canisters 10. A structure with a shaft 110 is rotatably mounted on a frame 112 and has five regular pentagonal support plates, including two outside plates 114 and three inside plates 115 mounted on the shaft 110. An upper holder member 116 and a lower holder member 118 with a shelf or plate 120 are mounted on each edge of the outside plates 114, and an upper holder member 122 and a lower holder member 124 with a support plate or shelf 126 are mounted on each edge of the inside plates 115 wherein the members 116 and 122, the members 118 and 124, and the shelves 120 and 126 are aligned in the respective rows. Contoured surfaces 128 are formed on the insides of the outer holder members 116 and 118 and on both sides of the inner holder members 122 and 124 parallel to the edges of the plates 114 and 115 for engaging the cylindrical canister 10. The shelves 120 and 126 extend perpendicular to the edges of the plates 114 and 115, and beyond the members 118 and 124 and their contoured surfaces at the bottoms of the lower members 118 and 124 for forming shelves to support the bottom of the canisters 10 in the loading station. Clamping arms 130 are pivotally mounted on the inside of each outer plate 114, and on both sides of each inner plate 115 and extend through the space between each pair of upper and lower members 116, 118, 122, and 124. Compression springs 132 mounted between the arms 130 and the plates 114 or 115 in front of the pivots bias the forward ends of the arms 130 against canisters received in the holders. Adjustable stops 134 are mounted on the rear ends of the arms 130 for determining the maximum rotative position of the arms 130 so that the canisters 10 may be easily pushed between the arms 130 by camming the forward ends of the arms 130 apart against the bias of springs 132. Half round tips 136 are formed on the forward ends of the arms 130 for engaging the respective sides of the canisters 10 to ensure their being held within the holders. Cam followers 140 are mounted on each of the clamp arms 136 and extend therefrom toward a center plane dividing each of the four spaces between the plates 114 and 115. Cams 142 for engaging the cam followers 140 to pivot the clamp arms 130 against the bias of springs 132 and release the arms from the canister 10 are mounted on the upper ends of each of four arms 144 which extend upward from the frame 112 along the planes bisecting the spaces between the plates 114 and 115.
An electric motor and speed reducer 150 controlled by index control circuit 151 drive a sprocket wheel 152 which is connected by a chain 154 to a drive sprocket 156 mounted on the shaft 110 for rotating the assembly of plates and holders in the direction of arrow 157 when initiated by operation of a push-button switch 158 connected to the index control circuit 151. Five equidistantly spaced pins 160 are mounted on the right side plate 114 for engaging a microswitch 162 connected to the circuit 151 to stop operation of the motor 150 at five index positions where a corresponding row of the holders is positioned at a loading station adjacent the elevator 12 receiving a row of canisters from the train of carriers 12.
At a contents unloading station defined by the second index position or 144° from the loading station, a chute 166 is suitably mounted on the frame 112 for directing the contents such as packaged logs of polymerized material 168 onto the conveyer 20. Four hammers 170 with rubber heads 172 are mounted on holders 174 which are pivotally mounted on frame members 176. Weighted arms 178 extend from the mounting members 174 perpendicular to the hammers 170 for gravity biasing the hammers in an upright position against a stop bar 180. Cords 182 are attached at one end to the respective arms 178 and pass over pulleys 184 to an operator station where an operator may actuate the hammers 170 for pounding the canisters 10 at the contents unloading station when failure to unload the contents 168 is observed through a mirror 186.
The conveyer 22 is positioned underneath the canister unloading station as determined by the position of the cams 142. This position is set to open the clamps 130 just before the canisters 10 reach an inverted vertical position, or about 180°, in rotation from the loading station. Guidewalls 190 and 192 are provided for aiding and directing the canisters 10 to upright upside positions on the conveyer 22.
In operation of the canister handling system of FIGS. 1-6, a train of the carriers 12 is pushed from the conveyer system past the raised stop 83 onto the elevator rail section 80, wherein the top most row of the canisters 10 within the four carriers 12 in the train are aligned with the holders formed by the members 116, 118, 122 and 124 and shelves 120 and 126 at the loading position. Each carrier 12 may be rotated about its pivot with the roller 40 so that its opening 52 faces the corresponding holder. The canister 10 within each holder is then rotated to the orientation shown in FIG. 3 and the canister 10 pushed through the opening 152 into the corresponding holder on the loading mechanism 16. It is noted that the holders at the loading station generally have a vertical orientation for receiving the canisters 10 in the vertical position.
After the topmost row of canisters has been loaded into the unloading mechanism 16, the push button switches 90 and 158 are operated to raise the elevator 14 to present the next row of canisters 10 in the carrier train to the loading station and to rotate or index the unloader mechanism 16 by a rotation of 72°. The next row of canisters in the carriers 12 is then aligned with the next row of holders on the unloading mechanism 16 and is loaded thereon as described above whereupon switches 90 and 158 are again operated. The loading of rows of canisters continues until the carriers 12 on the elevator are empty at which time push button switch 92 is operated to lower the elevator 14 to its lowermost position as shown in FIG. 5. The stop 87 is raised by manually rotating the arm 88 and the empty train of carriers is pushed from rail section 80 past stop 89 back onto the rail system 44. A new train of carriers can be unloaded as described above.
When the canisters 10 have been indexed twice or rotated through 144° by the unloader 16 to reach the contents unloading station, the canisters 10 are partially inverted. The contents or the packaged logs of polymerized material 168 will generally fall from the canisters 10 onto the chute 166 and the conveyer 20. However, one or more packages 168 may be stuck in the canisters 10 as observed through the mirror 186. The operator may then pull on the corresponding cord 182 to bang the corresponding hammer head 172 against the canister 10 and effect the release of the contents onto the conveyer 20.
During the next index cycle, the cam followers 140 engage the cams 142 to release the clamps 130 just as, or slightly before the row of empty canisters 10, passing from the contents unloading station, pass through an inverted vertical position. This results in the empty canisters 10 falling under the force of gravity from their holders onto the conveyer 22. The conveyer 22 carries the canisters then to a cleaning station (not shown) and to a further processing area where the canisters will be reloaded with monomer.
Continued rotation and indexing of the unloader mechanism 16 will return the holders to the loading position to receive additional rows of canisters 10 from trains of carriers 12.
The unloader mechanism 16 with five rows of canister holders positioned tangentially about the rotating support results in a improved and efficient operation. The canisters are loaded in a vertical position simply by pushing from the carriers 12, the canister contents are unloaded in a partially inverted position, and the emptied canisters are unloaded in the inverted position for easier handling at the subsequent cleaning station. By having five sides, the canister unloading position corresponds to one index stop of the unloader with the canisters oriented at 54° from the horizontal to unload the contents onto the conveyer 20. Other configurations of holders, such as arrangements of three rows of holders, and any combination containing more than five rows of holders may also be employed and have a stop position at the contents unloading station. The preferred five-sided arrangement has the particular advantage that the unloading angle is relatively steeper than a three-sided arrangement or a six-sided arrangement.
Since many modifications, variations and changes in detail may be made to the above-described embodiment, it is intended that all matter described in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. | In a canister handling system, a canister dumper has pentagonally arranged rows of holders on a structure which is rotatable about a horizontal axis for indexing the rows of holders from a vertical position, where the canisters are loaded, through two steps to a canister content unloading station where the contents are gravity unloaded, and then through a canister unloading station where the canisters are dropped from the holders. The canisters include vertical ribs defining an enlarged outside diameter which interlocks with curved carrier walls to retain the canisters on carriers. | 1 |
BACKGROUND OF THE INVENTION
[0001] Inversion therapy is a method for achieving a decompression of the musculoskeletal system. Spinal traction occurs when the head is at a lower plane of elevation than the feet, thereby reversing the normal gravitational loading that occurs while standing or sitting.
[0002] The degree of traction is measured by the angular displacement of the head from the horizontal plane that exists while lying flat in a prone position. The range of traction is therefore zero to ninety degrees, with maximum traction occurring while suspended orthogonal to the level surface below.
[0003] Gravity boots are an established method for enabling an inverted posture through ankle-based suspension. Traditional gravity boot designs use hooks which connect to an elevated horizontal bar. This requires attaching a pair of gravity boots to the ankles, and then raising the feet to the elevation of the bar in order to enter the inverted posture.
SUMMARY OF THE INVENTION
[0004] The purpose of the device described is to provide a means for suspension by the ankles in a fully inverted position and thereby achieve maximum traction. Pull-up bars, of the type used in gymnastics and fitness activities that are designed to support the static loads generated by human body weight, are the intended support structures for this device to be used in conjunction with.
[0005] The device described can be constructed from synthetic polymer webbing that has a rated tensile strength which determines the safe working load that can be supported. It is sewn together, according to the described design, using synthetic polymer thread that is also rated in terms of the load-bearing capacity of each stitch (pounds/stitch). This combination of materials provides a means to predict the maximum load bearing capacity of this device when assembled, and thereby incorporate large safety factors.
[0006] Advantages to using the device described for ankle-based inversion therapy are:
1. The device adds no weight to the ankles. When the feet are raised up toward the mounting bar, no extra load must be carried, which translates to less effort required. 2. The device described, when mounted to a horizontal support bar, has handles that are significantly lower in elevation than the bar itself. This makes it unnecessary to reach all the way to the bar when exiting the inverted position, because the device has extended handles that are closer to the hands 3. The load tension of applied body-weight causes the device to close around the ankles, due to its self-tightening nature. It is therefore not possible to fall or slip out of the device while in the inverted position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 depicts the device described, with numbers referring to the individual components outlined in the claims section.
[0011] FIG. 2 depicts two devices attached to a horizontal mounting bar and secured around both ankles while in use.
[0012] FIG. 3 depicts a pair of devices, showing the directional difference between the left and right version.
[0013] FIG. 4 depicts an as-built test model assembled from webbing and thread.
[0014] FIG. 5 depicts an as-built test model with a toe-hold loop of adjustable position relative to the main device body and a handle composed of separate finger loops.
[0015] FIG. 6 depicts an as-built test model based on the design shown in FIG. 1 .
[0016] FIG. 7 a shows the handle augmented with surrounding material to provide more grip surface.
[0017] FIG. 7 b shows the handle composed of individual finger loops.
[0018] FIG. 8 depicts the self-encircling part of the primary loop in isolation, with the black region representing a protective covering attached on the inside to prevent abrasion. The sheath could be made of durable and flexible plastic-polymer, and would eliminate friction contact between layers of webbing when the device is opened and closed. The sheath concept shown is a tubular single piece of material, and the webbing would be inserted through it prior to assembly.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Directions for Use:
[0020] Entry:
1. Verify that the left and right versions of the device are oriented correctly (the left should form a lowercase “D” letter shape, and the right should form a lowercase “B” letter shape, as shown in the figures). 2. Attach a pair of devices to the horizontal support bar, by placing the mounting loop over the bar and then threading the body of the device through the loop as shown in the figures. 3. Slide the main loop into its fully open position, by moving the self-encircling portion of the main loop upward. This provides the maximum open surface area for the foot to be inserted through. 4. Verify that the handle and its extension are within the interior region of the sliding portion of the main loop, as shown in the figures. 5. Grasp the handle of the left-foot device with the left hand, and grasp the right-foot device handle with the right hand, and verify that all connections are secure by lifting feet off the ground and applying body-weight load to the pair of devices. 6. Raise feet upward to the bar while holding device handles, and lean back simultaneously to minimize the amount of upper-body effort used. 7. Position the device around each ankle by inserting the left and right foot through the opening provided by the main loop of each device while using the big toe of the opposite foot in conjunction with the toe-hold loop to further control the device. 8. While still holding the handles, tighten each device around the ankles by pulling both feet downward. 9. Release the handles and move backward into a fully inverted posture.
[0030] Exit:
1. Raise the torso upward until the handles are within reach. 2. Grasp the left handle with the left hand, and the right handle with the right hand. Apply load to each handle by pulling downward as if the weight of the upper body were being supported by the handles and their extensions. 3. Shifting the static load application point, as described in the previous step, allows the main loop of the device to be relaxed and expanded. While briefly supporting the majority of body weight with the handles, use the big toe of the opposite foot in conjunction with the toe-hold loop to pull the main loop off of each ankle and allow the feet to exit. 4. Using a controlled movement, while still holding the handles securely, lower the feet to the ground. Do not release the handles until footing is secure.
[0035] Optional but Recommended Steps Prior to Use:
1. Cover the mounting bar with tape or protective cloth, to prevent the abrasion of webbing or stitching by exposed rough metallic surfaces. 2. Wear a pair of tube socks with the toe box cut open to provide a protective padding barrier between skin and device webbing.
[0038] Instructions for Assembly:
[0039] The size of the device can be scaled depending on foot-size and ankle circumference. The relative dimensions of the major components, as shown in the figures and described in the claims, are critical. The handle loop must be large enough to accommodate the hand, the main loop must be large enough when fully expanded to accommodate the through-passage of the foot, and the handle extension must be of sufficient length for the extension to remain inside of the self-encircling sliding region of the main loop when it is fully contracted around the ankles. The mounting loop must also be large enough to encircle the supporting bar structure and allow the whole device to pass through.
[0040] An ideal construction material is polyester webbing, with 2″ width used for the main loop and body of the device, and 1″ width used for all other components. The width-reducing attachment interface between the main loop and the handle extension maximizes the surface area of the seams connecting these two components.
[0041] Webbing used for assembly is heat sealed at exposed ends to prevent fraying. Heat-treated ends are hard and brittle and must be folded over once and sewn in place to prevent contact abrasion.
[0042] Sheaths to prevent webbing abrasion can be installed on sections of the device that are exposed to friction. These sections can include the self-encircling, sliding region of the main loop, the mounting loop, and the handle itself. The sheath can be made from durable fabric by sewing a tubular structure that surrounds the section of webbing being protected. The webbing would be inserted through the pre-fabricated tubular coverings prior to sewing. Single-piece molded polymer units could be used, if the plastic material were sufficiently durable and flexible.
[0043] The device can be constructed according to the drawings and descriptions using a sewing machine. The as-built test models of the device depicted in FIGS. 4-6 use reinforced box-tack stitching patterns at all major connection points. | A device used for ankle-based inversion therapy and which does not require hardware is described in this document. It allows the user to be suspended in an inverted posture from their ankles while being supported by an auxiliary mounting bar. The design of this device is presented in this document as an alternative to traditional hook-based gravity boots. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates generally to optical measurement and, more particularly, to a system and method for measuring the cell gap of a liquid crystal cell.
With the advent in semiconductor processes, electronic products are increasingly required to be lightweight, compact and low profile. Consequently, the fabrication of liquid crystal display (“LCD”) panels, which have been widely used in electronic products, has become more complex. An LCD panel usually comprises an upper glass substrate, a lower glass substrate and intermediate layers sandwiched between the glass layers. The intermediate layers may include a color filter layer, indium tin oxide (“ITO”) layers, alignment films and a liquid crystal cell filled with a liquid crystal. The thickness or the cell gap of the liquid crystal cell is an important factor to control because the properties such as display color, response speed and orientation stability of a liquid crystal cell depend upon the cell gap. Accordingly, in order to use a liquid crystal cell, it is important to measure the cell gap.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to a system and method for measuring the thickness of an object that obviate one or more problems resulting from the limitations and disadvantages of the prior art.
In accordance with an embodiment of the present invention, there is provided an optical measuring system that comprises a first confocal microscope for providing a first light beam in a first direction converging at a first focal plane, and a second confocal microscope for providing a second light beam in a second direction substantially opposed to the first direction converging at a second focal plane.
Also in accordance with the present invention, there is provided an optical measuring system that comprises a first confocal microscope including a first objective lens for providing a first light beam in a first direction converging at a first focal plane of the first objective lens, a second confocal microscope including a second objective lens for providing a second light beam in a second direction substantially opposed to the first direction converging at a second focal plane of the second objective lens, and a device for adjusting the position of one of the first focal plane and the second focal plane along an axis defined by the first and second directions.
Further in accordance with the present invention, there is provided a method for thickness measurement that comprises providing a first confocal microscope, emitting a first light beam from the first confocal microscope in a first direction, focusing the first beam at a first focal plane, providing a second confocal microscope, emitting a second light beam from the second confocal microscope in a second direction substantially opposed to the first direction, focusing the second beam at a second focal plane, and adjusting the relative position of the first and second microscopes by overlapping the first and second focal planes.
Still in accordance with the present invention, there is provided a method for thickness measurement that comprises providing a first confocal microscope including a first objective lens, emitting a first light beam from the first confocal microscope in a first direction, focusing the first beam at a first focal plane of the first objective lens, providing a second confocal microscope including a second objective lens, emitting a second light beam from the second confocal microscope in a second direction substantially opposed to the first direction, focusing the second beam at a second focal plane of the second objective lens, and providing an object including at least one layer.
Additional features and advantages of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The features and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
In the drawings:
FIG. 1A is a schematic diagram of a confocal microscope suitable for use in the present invention;
FIG. 1B is a schematic diagram illustrating an out-of-focus situation with the confocal microscope shown in FIG. 1A ;
FIG. 1C is a plot diagram illustrating the relationship between the displacement and relative intensity of a light beam received at a detector of the confocal microscope shown in FIG. 1A ;
FIG. 2A is a schematic diagram of an optical measuring system in accordance with one embodiment of the present invention;
FIG. 2B is a schematic diagram illustrating a method for operating the optical measuring system in accordance with one embodiment of the present invention;
FIG. 3 is a flow diagram illustrating a method for thickness measurement in accordance with one embodiment of the present invention;
FIG. 4 is a schematic diagram of an interferometer suitable for use in the present invention;
FIG. 5 is a schematic diagram of an optical measuring system in accordance with another embodiment of the present invention;
FIG. 6A is a schematic diagram of an object including multiple transparent layers; and
FIG. 6B is a flow diagram illustrating a method for measuring the thickness of the object shown in FIG. 6A in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
FIG. 1A is a schematic diagram of a confocal microscope 10 suitable for use in the present invention. Referring to FIG. 1A , the confocal microscope 10 includes a light source 11 , a first lens 12 - 1 , a second lens 12 - 2 , a beam splitter 13 , a first objective lens 14 - 1 , a second objective lens 14 - 2 and a detector 15 with a pinhole 15 - 1 . The light source 11 , first lens 12 - 1 and second lens 12 - 2 provide a laser beam toward an object 16 . The laser beam, passing through the first lens 12 - 1 , second lens 12 - 2 , beam splitter 13 , is focused by the first objective lens 14 - 1 on a focal plane 17 - 1 associated with the first objective lens 14 - 1 , and then reflected therefrom. The object 16 , which is disposed at the focal plane 17 - 1 , is in-focus with the first objective lens 14 - 1 . The reflected light beam, which coincides with the incident laser beam, is recollected by the first objective lens 14 - 1 and reflected by the beam splitter 13 toward the detector 15 through the second objective lens 14 - 2 . Since the pinhole 15 - 1 is located at a focal plane associated with the second objective lens 14 - 2 , the reflected light beam from the focal plane 17 - 1 is focused at the pinhole 15 - 1 and entirely pass to the detector 15 .
FIG. 1B is a schematic diagram illustrating an out-of-focus situation with the confocal microscope 10 shown in FIG. 1A . Referring to FIG. 1B , an incident light beam 17 is focused by the first objective lens 14 - 1 on the focal plane 17 - 1 . However, since the object 16 is disposed away from the focal plane 17 - 1 , only a portion of the reflected light beam (illustrated in dotted lines) is received by the detector 15 . Specifically, a light beam from below the focal plane 17 - 1 comes to a focus before reaching the pinhole 15 - 1 , and then expands out so that most of the light beam is physically blocked from reaching the detector 15 by the pinhole 15 - 1 . In the same way, a light beam from above the focal plane 17 - 1 is focused behind the pinhole 15 - 1 , so that most of light beam also hits the edges of the pinhole 15 - 1 and is not detected.
FIG. 1C is a plot diagram illustrating the relationship between the displacement and relative intensity of a light beam received at the detector 15 of the confocal microscope 10 shown in FIG. 1A . Referring to FIG. 1C , for an in-focus situation where an object is located at a focal plane, the relative intensity ratio, i.e., the intensity of a received light beam to that of an incident light beam, is approximately 1, which may be used as a measurement threshold for the confocal microscope 10 . For an out-of-focus situation where an object is located away from a focal plane, the relative intensity ratio decreases as the displacement increases.
FIG. 2A is a schematic diagram of an optical measuring system 20 in accordance with one embodiment of the present invention. The optical measuring system 20 includes a first confocal microscope 30 and a second confocal microscope 40 . The first confocal microscope 30 , having a similar structure to the confocal microscope 10 illustrated in FIG. 1A , includes a light source 31 , a first lens 32 - 1 , a second lens 32 - 2 , a beam splitter 33 , a first objective lens 34 - 1 , a second objective lens 34 - 2 and a detector 35 with a pinhole 35 - 1 . The light source 31 , first lens 32 - 1 and second lens 32 - 2 provide a first light beam in a first direction 37 . The first light beam passes through the beam splitter 33 and is focused by the first objective lens 34 - 1 at a focal plane of the first objective lens 34 - 1 . A reflected light beam is collected by the first objective lens 34 - 1 and reflected by the beam splitter 33 toward the detector 35 through the second objective lens 34 - 2 and pinhole 35 - 1 .
In the same manner, the second confocal microscope 40 , having a similar structure to the confocal microscope 10 illustrated in FIG. 1A , includes a light source 41 , a first lens 42 - 1 , a second lens 42 - 2 , a beam splitter 43 , a first objective lens 44 - 1 , a second objective lens 44 - 2 and a detector 45 with a pinhole 45 - 1 . The light source 41 , first lens 42 - 1 and second lens 42 - 2 provide a second light beam in a second direction 47 substantially opposed to the first direction 37 . The second light beam passes through the beam splitter 43 and is focused by the first objective lens 44 - 1 at a focal plane of the second objective lens 44 - 1 . A reflected light beam is collected by the first objective lens 44 - 1 and reflected by the beam splitter 43 toward the detector 45 through the second objective lens 44 - 2 and pinhole 45 - 1 . The second confocal microscope 40 further includes a sliding device 46 for moving the first objective lens 44 - 1 with respect to the light source 41 along an axis defined by the first direction 37 and second direction 47 . In one embodiment according to the present invention, the first objective lens 44 - 1 is loaded on the sliding device 46 to move along the axis. Skilled persons in the art will understand that other device capable of adjusting the focus point of the first objective lens 44 - 1 along the axis may be used to replace the sliding device 46 . Furthermore, the first confocal microscope 30 may include a device similar to the sliding device 46 for moving the first objective lens 34 - 1 along the axis.
An object 50 , for example, a liquid crystal cell, including a liquid crystal layer 53 sandwiched by transparent layers 51 and 52 such as glass substrates, is disposed between the first confocal microscope 30 and second confocal microscope 40 . To measure the thickness of the object 50 , or the cell gap of the liquid crystal cell, the relative position of the first confocal microscope 30 and the second confocal microscope 40 is reset. FIG. 2B is a schematic diagram illustrating a method for operating the optical measuring system 20 in accordance with one embodiment of the present invention. Referring to FIG. 2B , before positioning the object 50 between the first confocal microscope 30 and second confocal microscope 40 , the second confocal microscope 40 is moved along the axis with respect to the first confocal microscope 30 till the focal plane of the first objective lens 34 - 1 overlaps the focal plane of the first objective lens 44 - 1 at a first position plane 48 . The position of the sliding device 46 is then recorded.
Next, referring again to FIG. 2A , the object 50 is positioned between the first confocal microscope 30 and second confocal microscope 40 . The object 50 is moved along the axis till a first interface 531 between the liquid crystal layer 53 and one transparent layer 51 overlaps the focal plane of the first objective lens 34 - 1 . Next, the sliding device 46 , on which the first objective lens 44 - 1 is loaded, is moved along the axis toward the light source 41 till a second interface 532 between the liquid crystal layer 53 and the other transparent layer 52 overlaps the focal plane of the first objective lens 44 - 1 . The new position of the sliding device 46 is then recorded. The thickness of the object 50 is determined by the recorded positions of the sliding device 46 .
FIG. 3 is a flow diagram illustrating a method for thickness measurement in accordance with one embodiment of the present invention. Referring to FIG. 3 , at step 51 , a first confocal microscope is provided for providing a first light beam in a first direction along an axis converging at a first focal plane. At step 52 , a second confocal microscope is provided for providing a second light beam along the axis converging at a second focal plane. The second light beam travels in a second direction substantially opposed to the first direction. Next, at step 53 , the relative position of the first confocal microscope and the second confocal microscope is reset by moving the second confocal microscope along the axis till the first focal plane overlaps the second focal plane. When overlapped, a maximum relative intensity ratio is detected. The position of an objective lens of the second confocal microscope associated with the second focal plane is then recorded. At step 54 , an object including a layer further including a first side and a second side is positioned between the first confocal microscope and the second confocal microscope. Next, at step 55 , the object is moved along the axis till the first side overlaps the first focal plane. At step 56 , the position of the second focal plane is adjusted by moving the objective lens associated with the second focal plane till the second side overlaps the second focal plane. The new position of the objective lens of the second confocal microscope is then recorded. The layer thickness of the object is determined from the recorded positions of the objective lens associated with the second focal plane.
FIG. 4 is a schematic diagram of an interferometer 60 suitable for use in the present invention. An interferometer works on the principle that two optical waves that coincide with the same phase will amplify each other while two optical waves that have opposite phases will cancel each other out. Referring to FIG. 4 , the interferometer 60 , for example, a Michelson interferometer, includes a detector 61 , reflecting mirrors 62 - 1 and 62 - 2 , and a beam splitter 63 , which is usually a semitransparent mirror. There are two optical paths from a light source toward the detector 61 . One reflects off the beam splitter 63 , travels to one reflecting mirror 62 - 2 and then reflects back, goes through the beam splitter 63 to the detector 61 . The other one travels through the beam splitter 63 to the other reflecting mirror 62 - 1 , reflects back to the beam splitter 63 , then reflects therefrom into the detector 61 . If these two optical paths differ by a whole number (including 0) of wavelengths, there is constructive interference and a strong signal at the detector 61 . If they differ by a whole number and a half wavelengths, there is destructive interference and a weak signal at the detector 61 .
FIG. 5 is a schematic diagram of an optical measuring system 70 in accordance with another embodiment of the present invention. Referring to FIG. 5 , the optical measuring system 70 has a similar structure to the optical measuring device 20 illustrated in FIG. 2A except that a first confocal microscope 80 includes an interferometer 89 and a second confocal microscope 90 includes an interferometer 99 . The interferometer 89 , which has a similar structure to the interferometer 60 illustrated in FIG. 4 , is disposed between the first objective lens 34 - 1 and the focal plane of the first objective lens 34 - 1 . In the same manner, the interferometer 99 , which has a similar structure to the interferometer 60 illustrated in FIG. 4 , is disposed between the first objective lens 44 - 1 and the focal plane of the first objective lens 44 - 1 . With the interferometers 89 and 99 , the sensitivity and resolution of the first confocal microscope 80 and second confocal microscope 90 may be increased. In one embodiment according to the present invention, the measurement threshold of the optical measuring system 70 , also referring to FIG. 1C , is approximately 1, and the maximum slope of the plot A is greater than or equal to that of an envelop B. The maximum slope of the envelop B may occur at a section corresponding to the ratio ranging between 0.4 to 0.6.
FIG. 6A is a schematic diagram of an object 100 including multiple transparent layers. Referring to FIG. 6A , the object 100 includes a liquid crystal layer 101 , a pair of alignment layers 102 - 1 and 102 - 2 sandwiching the liquid crystal layer 101 , a pair of indium tin oxide (“ITO”) layers 103 - 1 and 103 - 2 sandwiching the alignment layers 102 - 1 and 102 - 2 , and a pair of glass substrates 104 - 1 and 104 - 2 sandwiching the ITO layers 103 - 1 and 103 - 2 .
FIG. 6B is a flow diagram illustrating a method for measuring the thickness of the object 100 shown in FIG. 6A in accordance with one embodiment of the present invention. Referring to FIG. 6B , at step 111 , a first confocal microscope is provided for providing a first light beam in a first direction along an axis converging at a first focal plane. At step 112 , a second confocal microscope is provided for providing a second light beam along the axis converging at a second focal plane. The second light beam travels in a second direction substantially opposed to the first direction. Next, at step 113 , the relative position of the first confocal microscope and the second confocal microscope is reset by moving the second confocal microscope along the axis till the first focal plane overlaps the second focal plane. The position of an objective lens of the second confocal microscope associated with the second focal plane is then recorded. At step 114 , an object including multiple layers transparent to the first light beam and second light beam is positioned between the first confocal microscope and the second confocal microscope. Next, at step 115 , the object is moved along the axis till a first interface of the multiple layers overlaps the first focal plane. The first interface includes a first side of the object. At step 116 , the position of the second focal plane is adjusted by moving the objective lens associated with the second focal plane till a second interface corresponding to the first interface overlaps the second focal plane. The second interface includes a second side of the object. The new position of the objective lens of the second confocal microscope is then recorded. The thickness of a layer, for example, the liquid crystal layer, of the object is determined from the recorded positions of the objective lens associated with the second focal plane at step 117 . Next, a step 118 , it is determined whether to continue the measurement. If confirmative, the steps 113 to 117 are repeated for measuring the thickness of one of the remaining layers.
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
Further, in describing representative embodiments of the present invention, the specification may have presented the method and/or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention. | A system and a method for thickness measurement that comprises providing a first confocal microscope, emitting a first light beam from the first confocal microscope in a first direction, focusing the first beam at a first focal plane, providing a second confocal microscope, emitting a second light beam from the second confocal microscope in a second direction substantially opposed to the first direction, focusing the second beam at a second focal plane, and adjusting the relative position of the first and second microscopes by overlapping the first and second focal planes. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical-axis adjusting device for adjusting an irradiating direction of a light beam in a vehicle light radar device where a light beam is irradiated from a light-emitting source to an object of measurement, then the light reflected by the object is received, and a distance to the object is detected.
2. Description of Related Art
A conventional vehicle light radar device is known, for example, in Japanese Utility Model Laid-Open No. 5-55205. In this vehicle light radar device, a light beam is irradiated from a light-emitting source, then the reflected light from an object of measurement is received, and based on the relationship between the light transmission signal and the light reception signal, the distance to an object can be detected. The vertical and lateral adjustments of the light beam (optical axis) are made by performing the directional adjustment and the fixing operation of the beam transmitter-receiver. The vehicle light radar device is equipped with an adjusting device where the directional adjustment can be made from one direction.
An adjusting device such as that shown in FIG. 7 is known as another device for adjusting a direction of a light beam. In FIG. 7, a vehicle light radar device 1 is fixed at the opposite side surfaces thereof to a bracket 50 by means of screws 51 and 52. These screws 51 and 52 are spaced by a predetermined distance, and the slot 52a of the bracket 50 on the side of the screw 52 is formed into the shape of a circular arc with the screw 51 as a center. The vertical adjustment of the irradiating direction of the light beam of the vehicle light radar device 1 is performed by adjusting the fixed position of the screw 52 with respect to the circular arc-shaped slot 52a.
The bracket 50 is fixed to a plate 53 by means of fixation screws 54 and 55 and is attached to the vehicle through the plate 53. For the screws 54 and 55 for fixing the bracket 50 to the plate 53, the slot 55a of the plate 53, through which the screw 55 is inserted, is formed into the shape of a circular arc with the screw 54 as a center. The lateral adjustment of the irradiating direction of the light beam of the vehicle light radar device 1 is performed by adjusting the fixed position of the screw 55 with respect to the circular arc-shaped slot 55a.
The adjustment of the irradiating direction (optical axis) of the light beam of the vehicle light radar device needs to be performed after the light radar device is mounted on a vehicle. In a conventional vehicle light radar device such as described above, as shown in the mechanism of Japanese Utility Model Laid-Open No. 5-55205 or the mechanism of FIG. 7, the adjustment of the irradiating direction of the light beam is performed from the side surface positioned rearwardly of the device with respect to the front surface of the device, or from the upper surface or lower surface direction. For this reason, when mounting the vehicle light radar device on the vehicle, it becomes necessary to have an adjusting space for making an adjustment with respect to each of the surfaces. The necessity of this space becomes a large limitation when mounting the vehicle light radar device on the vehicle, and consequently, there is the problem that the ability of mounting the device on a vehicle is reduced.
Also, the adjusting device, shown in Japanese Utility Model Laid-Open No. 5-55205, has the disadvantage that the stability in the beam direction cannot be obtained due to the vibration caused by the traveling of a vehicle, because the fulcrum shaft is loose in the axial direction.
BRIEF SUMMARY OF THE INVENTION
An objective of the present invention is to provide an optical-axis adjusting device for a vehicle light radar device which is capable of enhancing the mounting ability to a vehicle by making an adjustment of an optical axis and a fixation after adjustment from the side originally having space where a light beam of the vehicle light radar device is irradiated.
Another objective of the present invention is to provide an optical-axis adjusting device for a vehicle light radar device which is capable of eliminating looseness caused by the traveling vibration of a vehicle and-obtaining stability in the beam direction.
To achieve the foregoing objectives and in accordance with an important aspect of the present invention, there is provided an optical-axis adjusting device for a vehicle light radar device which has a light-transmitting window for irradiating a beam of light to an object of measurement and a light-receiving window for receiving reflected light from said object, the optical-axis adjusting device, comprising adjusting means provided at the front of said light radar device for adjusting the irradiating direction of said beam of light.
With this arrangement, an adjustment and a fixation after adjustment can be made from the front side of the device where the light-transmitting window and the light-receiving window are disposed, and consequently, limitations on the mounting of the apparatus on a vehicle are considerably reduced.
In a preferred form of the invention, said adjusting means comprises adjustment screws for vertically and laterally rotating and adjusting the irradiating direction of said beam of light and fixation screws for maintaining a position adjusted by means of said adjustment screws.
With this arrangement, an adjustment and a fixation after adjustment can be made from the front side of the device where the light-transmitting window and the light-receiving window are disposed, and consequently, limitations on the mounting of the apparatus on a vehicle are considerably reduced.
In another preferred form of the invention, said fixation screws comprises vertical fixation screws for maintaining a position adjusted in a vertically rotated direction, the vertical fixation screws being disposed on a horizontal plane connecting vertical rotation fulcrums together, and a lateral fixation screw for maintaining a position adjusted in a laterally rotated direction, the lateral fixation screw being disposed on a plane which passes through a lateral rotation fulcrum and is substantially parallel to the irradiating direction of said beam of light.
With this arrangement, an adjustment and a fixation after adjustment can be made from the front side of the device where the light-transmitting window and the light-receiving window are disposed, and consequently, limitations on the mounting of the apparatus on a vehicle are considerably reduced.
In still another preferred form of the invention, the optical-axis adjusting device further comprises a first member fixed directly to said vehicle light radar device, a second member fixed directly to a vehicle, a third member provided between said first and second members, the third member constituting a rotation fulcrum portion which vertically and laterally rotates said first member with respect to said second member, and an elastic press member for pressing said first and second members together in the vicinity of said rotation fulcrum portion.
With this arrangement, the first and second members are pressed together by the elastic member with a force that can sufficiently stand the traveling vibration of a vehicle. As a result, the looseness of the fulcrum portion is eliminated, the influence of the traveling vibration on the beam of light is eliminated, and stability in the beam direction can be assured even during traveling.
In a further preferred form of the invention, the optical-axis adjusting device according to claim 5 further comprises a press mechanism for pressing said first and second members together, the press member being disposed concentrically of said lateral rotation fulcrum of said rotation fulcrum portion.
With this arrangement, the first and second members are pressed together at points other than the fulcrum portion and therefore the rigidities of the members are increased and the members can be made thinner. As a result, an optical-axis adjusting device, which is light in weight and low in cost, is obtainable.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages will become apparent from the following detailed description when read in conjunct ion with the accompanying drawings wherein:
FIG. 1 is a front view showing an embodiment of an optical-axis adjusting device for a vehicle light radar device of the present invention;
FIG. 2 is a side view showing the embodiment in FIG. 1 of the present invention;
FIG. 3 is a sectional view of the embodiment in FIG. 1 taken substantially along line I--I of FIG. 1;
FIG. 4 is a sectional view of the embodiment in FIG. 1 taken substantially along line II--II of FIG. 1;
FIG. 5 is a sectional view of the embodiment in FIG. 3 taken substantially along line III--III of FIG. 3;
FIG. 6 is a sectional view of the embodiment in FIG. 3 taken substantially along line IV--IV of FIG. 3; and
FIG. 7 is a perspective view showing a conventional device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention will hereinafter be described with reference to the drawings. In FIGS. 1-6, a vehicle light radar device 1 is equipped with a light-transiting window 2 and a light-receiving window 3 at the front surface thereof. The vehicle light radar device 1 is attached at its bottom portion to an upper plate 4, which in turn is attached to a lower plate 6. The lower plate 6 is attached to a bottom plate 5 attached to the vehicle.
The vehicle light radar device 1 is fixed to the upper plate 4 by means of screws 7. The upper and lower plates 4 and 6 are relatively rotatable about a fulcrum 8 in the lateral direction of the device 1. For this reason, the upper plate 4 is provided integrally with a first projection 9 having a female screw. The lower plate 6 is provided integrally with a first projection 10 having a U-shaped groove, and the first projection 10 of the lower plate 6 pairs with the first projection 9 of the upper plate 4. An adjustment screw 11 is screwed into the female screw of the projection 9 of the upper plate 4 and is provided with a groove 11a which engages with the U-shaped groove of the projection 10 of the lower plate 6.
In addition, the adjustment screw 11 is urged in one direction by means of a spring 12. The upper plate 4 is further provided integrally with a second projection 13 having a female screw, formed into the shape of a circular arc with the fulcrum 8 as a center. The lower plate 6 is further provided integrally with a second projection 14 which pairs with the projection 13 of the upper plate 4. The second projection 14 of the lower plate 6 has a laterally elongated slot, which is formed into the shape of a circular arc with the fulcrum 8 as a center. These projections 13 and 14 are fixed with each other by means of a screw 15 screwed into the female screw provided in the projection 13 of the upper plate 4.
The lower plate 5 and the bottom plate 6 are relatively rotatable about a fulcrum 16 in the vertical direction of the device 1. For this reason, the lower plate 6 is provided integrally with a third projection 17 having a female screw, while the bottom plate 5 is provided integrally with a first projection 18 which has a U-shaped groove so as to pair with the third projection 17. An adjustment screw 19, urged into one direction by means of a spring 20, is screwed into the female screw of the projection 17 of the lower plate 6 and is provided with a groove 19a which engages with the U-shaped groove of the first projection 18 of the bottom plate 5.
In addition, the lower plate 6 is provided integrally with a fourth projection 21 having a female screw, and the projection 21 is formed into the shape of a circular arc with the fulcrum 16 as a center. That is, the projection 21 is curved in the vertical direction so that the lower plate 5 and the bottom plate 6 are relatively rotatable about the fulcrum 16 in the vertical direction. Likewise, the bottom plate 5 is provided integrally with a second projection 22 so that the projection 22 pairs with the projection 21 of the lower plate 6. The second projection 22 of the bottom plate 5 has a vertical slot and is formed into the shape of a circular arc with the fulcrum 16 as a center. These projections 21 and 22 are fixed together by means of a screw 23 screwed into the female screw provided in the projection 21 of the lower plate 6.
Furthermore, the bottom plate 5 is provided integrally with a third projection 24 constituting the fulcrum 16, while the lower plate 6 is provided integrally with a fifth projection 25 constituting the fulcrum 16. The fulcrum shaft of the fulcrums 8 and 16 is shown in FIG. 5 as 26. An elastic spring 27 is fitted on the fulcrum shaft 26 so that the plates 4 and 6 are clamped together. In addition, a washer 28 is inserted on the fulcrum shaft 26 and undergoes the reaction force of the spring 27.
The upper plate 4 and the lower plate 6 are relatively movable on a concentrical circle of the fulcrum 8. For this reason, an oblique slot 29 is formed in the upper plate 4, and a hole 30 is formed in the lower plate 6 so as to pair with the slot 29. Also, a pin 31 is inserted into the hole 30 and the slot 29. An elastic spring 32 is inserted on the pin 31 so that the plates 4 and 6 are clamped together. A washer 33 is also inserted on the pin 31 and undergoes the reaction force of the spring 32 at the slot side.
Now, the operation will be described with reference to FIGS. 1 and 6. The vehicle light radar device 1 irradiates a predetermined beam of light from the light transmitting window 2. The light beam irradiated from the light-transmitting window 2 is reflected by an object of measurement and then returns to the light-receiving window 3. A distance to the object is obtained from the relationship between the light transmission signal and the light reception signal at this time.
This vehicle light radar device 1 is fixed to the plate 4 by the screws 7 and is attached to the vehicle through the plates 6 and 5. When attaching the device 1 to the vehicle, it is necessary to adjust the orientation of the device 1 so that the light beam irradiated from the light transmitting window 2 is accurately irradiated to the range of the object of measurement.
Initially, the lateral adjustment of the vehicle light radar device 1 will be described based on FIGS. 3 and 4. The screw 15 is loosened before adjustment. Then, if the adjustment screw 11 is rotated so as to be screwed into the female screw of the projection 9 of the upper plate 4, the groove 11a of the adjustment screw 11 will be moved in a direction away from the projection 9 of the upper plate 4. Then, the projection 10 of the lower plate 6 having a U-shaped groove engaged by the groove 11a is caused to rotate about the fulcrum 8 in the direction away from the projection 9 of the upper plate 4.
If, on the other hand, the adjustment screw 11 is rotated so as to be unscrewed from the female screw of the projection 9 of the upper plate 4, then the groove 11a of the adjustment screw 11 will be moved in the direction toward the projection 9 of the upper plate 4. Then, the projection 10 of the lower plate 6 having a U-shaped groove engaged by the groove 11a is caused to rotate about the fulcrum 8 in the direction toward the projection 9 of the upper plate 4.
The upper plate 4, therefore, laterally or horizontally rotates about the fulcrum 8 with respect to the lower plate 6, depending upon the direction of rotation of the adjustment screw 11. In this way, the position of the vehicle light radar device 1 is adjusted so that the light beam from the light transmitting window 2 of the device 1 can be accurately irradiated to the lateral range of the object of measurement. Thus, if the lateral or horizontal position of the vehicle light radar device 1 is determined, then the screw 15 will be tightened to fix the upper and lower plates 4 and 6 together through the projections 13 and 14.
Next, the vertical adjustment of the vehicle light radar device 1 will be described based on FIGS. 3 and 4.
First, the screws 23 are loosened before adjustment. Then, if the adjustment screw 19 is rotated so as to be screwed into the female screw of the projection 17 of the lower plate 6, the groove 19a of the adjustment screw 19 will be moved in the direction away from the projection 17 of the lower plate 6. Then, the projection 18 of the bottom plate 5 having a U-shaped groove engaged by the groove 19a is caused to rotate about the fulcrum 16 in the direction away from the projection 17 of the lower plate 6.
If, on the other hand, the adjustment screw 19 is rotated so as to be unscrewed from the female screw of the projection 17 of the lower plate 6, then the groove 19a of the adjustment screw 19 will be moved in the direction toward the projection 17 of the lower plate 6. Then, the projection 18 of the bottom plate 5 having a U-shaped groove engaged by the groove 19a is caused to rotate about the fulcrum 16 in the direction toward the projection 17 of the lower plate 6.
The lower plate 6, therefore, vertically rotates about the fulcrum 16 with respect to the bottom plate 5, depending upon the direction of rotation of the adjustment screw 19. In this way, the position of the vehicle light radar device 1 is adjusted so that the light beam from the light transmitting window 2 of the device 1 can be accurately irradiated to the vertical range of the object of measurement.
Thus, if the vertical position of the vehicle light radar device 1 is determined, then the screws 23 will be tightened to fix the lower and bottom plates 6 and 5 together through the projections 21 and 22. In this way, the lateral and vertical adjustments and the fixing after the adjustments can be performed from the front side of the device 1 where the light-transmitting window 2 and the light-receiving window 3 are disposed, and consequently, the limitations on the mounting of the device on a vehicle can be considerably reduced.
In addition, with the pressing force of the spring 27, the plates 4 and 6 in the vicinity of the fulcrum 8 are pressed together and the plates 6 and 5 in the vicinity of the fulcrum 16 are pressed together, as shown in FIG. 5. The pressing force of the spring 27 is set so that the vibration caused by the traveling of a vehicle can be sufficiently absorbed, the vehicle light radar device 1 can be stably supported, and the irradiating direction can be stabilized.
Furthermore, as shown in FIGS. 3 and 6, the plates 4 and 6 in the vicinity of the fulcrum 8 are pressed together concentrically with respect to the fulcrum 8 with a predetermined force by the spring 32. Consequently, the rigidities of the plates 4 and 6 are enhanced, the vehicle light radar device 1 is stably supported, and the irradiating direction is stabilized.
While the present invention has been described with relation to the preferred embodiment, various modifications and adaptations thereof will now be apparent to those skilled in the art. All such modifications and adaptations as fall within the scope of the appended claims are intended to be covered thereby. | Disclosed herein is an optical-axis adjusting device for a vehicle light radar device where a light-transmitting window for irradiating a beam of light to an object of measurement and a light-receiving window for receiving reflected light from the object are disposed. The optical-axis adjusting device comprises an adjusting unit provided at the front of the light radar device for adjusting the irradiating direction of the beam of light. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to locking assemblies and, more particularly, to a locking device for a docking station.
[0003] 2. Description of related art
[0004] Portable computers, such as notebook computers and personal digital assistants (PDAs), are popular and commonly used devices that provide users with mobile computing power in small, lightweight, portable packages. The portable computer usually offers less functions than a desktop computer because the portable computer may lack certain peripheral devices (e.g. a CD-ROM drive or a floppy drive).
[0005] A docking station has been developed to enhance and extend functions found in a desktop computer to a portable computer. The docking station typically provides a plurality of hooks engaging in a plurality of corresponding holes defined in the portable computer, thus, establishing a stable mechanical fixation between the portable computer and the docking station. Therefore, undesired divorces between the portable computer and the docking station are prevented. A release button is pressed to make the hooks separate from the holes when the portable computer is removed from the docking station.
[0006] However, a continuance of the pressure on the release button applied by a hand of a user is unavoidable before the portable computer is entirely removed from the docking station by another hand of the user. Obviously, the user cannot withdraw the hand pressing the release button while another hand holding the portable computer during the divorce between the portable computer from the docking station. Therefore, great inconvenience is generated.
[0007] Therefore, a locking device for a docking station with a higher convenience is desired.
SUMMARY OF THE INVENTION
[0008] A locking device includes a case defining at least one slot therein, a hook module including at least one hook for passing through the at least one slot, a linkage module includes at least one first lever configured for shifting the at least one hook to move between a locking position and a releasing position, and a positioning module for releasably engaging with the first lever. When the at least one hook is shifted to the releasing position, the first lever is blocked by the positioning module, when the at least one hook is shifted to the locking position, the first lever is released by the positioning module.
[0009] Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is an isometric view of a locking device for a docking station in accordance with an exemplary embodiment;
[0011] FIG. 2 is an exploded, isometric view of the locking device of FIG. 1 ;
[0012] FIG. 3 is another exploded, isometric view of the locking device of FIG. 1 ;
[0013] FIG. 4 is an exploded, enlarged, isometric view of a positioning module of the locking device of FIG. 3 ;
[0014] FIG. 5 is an exploded, enlarged, isometric view of a positioning module of FIG. 3 ;
[0015] FIG. 6 is an isometric view of a detecting pin of the positioning module of FIG. 3 ;
[0016] FIG. 7 is a side view of a portable computer and a docking station of FIG. 1 ;
[0017] FIG. 8 is a side view of the portable computer incorporating the docking station of FIG. 1 ;
[0018] FIGS. 9A to 9C are bottom views of the positioning module of FIG. 3 , showing relative movements of a positioning portion and a detecting portion; and
[0019] FIG. 10 is an isometric view of a docking station employing the locking device of the FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0020] In the following embodiment, a locking device for a docking station is used as an example for illustration. It is noted that docking station in the embodiment may be used for portable computers, cell phones, power chargers, or any other portable electronic apparatuses.
[0021] Referring to FIGS. 1 to 3 , a locking device 10 according to an exemplary embodiment is illustrated. The locking device 10 includes a release button 21 , a linkage module 23 , two hook modules 25 , a first spring 27 , a second spring 29 , a positioning module 31 and a case 40 .
[0022] The release button 21 is capable of moving along a first direction Z, and includes a cap 222 for capable of receiving a pressure, a pressing post 224 with a first inclined surface 226 forming thereof, and a plurality of clasps 228 . The pressing post 224 perpendicularly extends from a center of the cap 222 for transmitting the pressure to the linkage module 23 . The first inclined surface 226 forms at a free end of the pressing post 224 opposite to the cap 222 for engaging with the linkage module 23 . The clasps 228 perpendicularly extend from a periphery of the cap 222 for slidably engaging with the case 40 .
[0023] The linkage module 23 includes a first lever 24 , a second lever 26 , and a pair of third levers 28 . The first lever 24 and the pair of third levers 28 are spaced from each other. The first lever 24 is substantially perpendicular to the second lever 26 and parallel to the pair of third levers 28 . The pair of third levers 28 and the first lever 24 are arranged at two opposite sides of the second lever 26 .
[0024] The first lever 24 is movable long a second direction Y, and includes a second inclined surface 242 for engaging with the first inclined surface 226 of the release button 21 , a third inclined surface 244 for engaging with the second lever 26 , a protrusion 248 extending from the first lever 24 along a direction opposite of a third direction X, a first guiding rod 250 extending from the protrusion 248 along a direction reversed to the second direction Y for the first spring 27 to be sleeved/engaged therearound. The second inclined surface 242 and the third inclined surface 244 are formed at two opposite ends of the first lever 24 . Two first guiding slots 246 are defined in the first lever 24 and extend along the second direction Y.
[0025] Referring also to FIGS. 4 and 5 , the second lever 26 is movable along the third direction X, and includes a fourth inclined surface 262 for engaging with the third inclined surface 244 of the first lever 24 , a second guiding rod 264 extending from a distal end of the second lever 26 opposite to the fourth inclined surface 262 for the second spring 29 sleeving therearound, and a pair of first mounting posts 270 for slidably mounting a first positioning portion 34 . A second concave 272 is defined on the second lever 26 for receiving a third spring 35 . Three second guiding slots 266 are defined in the second lever 26 , and extend along the third direction X. Two traction slots 268 are cam-like and are defined on the second lever 26 for guiding movements of the pair of third levers 28 .
[0026] The positioning module 31 includes the first positioning portion 34 , the third spring 35 , a second positioning portion 36 , and a fourth spring 37 . The first positioning portion 34 is substantially T-shaped, and includes a first plate 342 , a second plate 343 perpendicularly attached to an edge of the first plate 342 , and a first rack 344 positioned on the second plate 342 for engaging with the second positioning portion 36 . A first angle β is defined between an elongated direction of the first rack 344 and the first plate 342 . The first angle β is greater that 0 degree and less than 90 degrees. A pair of third guiding slots 346 are defined on the two opposite side of the first plate 342 for the first mounting posts 270 to be slidably engaged in. The third spring 35 is accommodated in the second concave 272 , and interconnects an inner side of the second concave 272 and the first positioning portion 34 with its two opposite ends. The second positioning portion 36 includes a detecting pin 362 for detecting whether a portable computer 50 (shown in FIG. 7 ) is loaded, a base 364 for mounting the detecting pin 362 , a second rack 366 arranged at a sidewall of the base 364 for engaging with the first rack 344 . A second angle θ is defined between an elongated direction of the second rack 366 and the base 364 that equals to the first angle β. That is, the second rack 366 conforms to the first rack 344 . When the first rack 344 engages the second rack 366 , two component of forces are generated along the first direction Z and the third direction X respectively. A third concave 368 is defined on the base 364 opposite to the detecting pin 362 for accommodating the forth spring 37 .
[0027] Referring also to FIG. 6 , each of the pair of third levers 28 includes a sliding pin 282 perpendicularly extending from one end of the third lever 28 for engaging in the traction slot 268 . A retaining ring 284 is defined in an opposite end of the third lever 28 for engaging with the hook module 25 . Each hook module 25 includes a hook 30 , a torsion spring 32 , and a mounting cover 33 . The hook 30 includes a hook end 302 , and an opposite pivot end 304 for the hook end 302 to rotate around. The hook end 302 extends through the retaining ring 284 . The mounting cover 33 secures the hook 30 onto an inner side of the case 40 .
[0028] Referring back to FIGS. 1 and 2 , the case 40 defines a first concave 42 for receiving the release button 21 , two inserting slots 44 for the corresponding hook end 302 of the hook module 25 to be inserted through correspondingly, a through hole 46 for the detecting pin 362 of the second positioning portion 36 inserting therethrough.
[0029] Referring back to FIG. 3 , the case 40 , viewed from its inner side, includes two second mounting posts 412 , a first blocking sheet 414 , three third mounting posts 416 , a second blocking sheet 418 , a positioning base 420 , and two mounting base 422 corresponding to the mounting covers 33 . The two second mounting posts 412 are arranged along the second direction Y for engaging in the first guiding slots 246 correspondingly. The first blocking sheet 414 supports a free end of the first guiding rod 250 , and blocks the first spring 27 between the protrusion 248 of the first lever 24 and the first blocking sheet 414 . The three third mounting posts 416 are arranged along the third direction X for engaging in the second guiding slots 266 correspondingly. A second blocking sheet 418 supports a free end of the second guiding rod 264 , and blocks the second spring 29 between the end of the second lever 26 and the second blocking sheet 418 . The positioning base 420 is substantially U-shaped for enclosing the second positioning portion 36 . Each mounting base 422 defines two bearing portions 424 for rotatably supporting the pivot end 304 of the hook 30 , and is capable of being covered by the mounting cover 33 . The torsion spring 32 interconnects the hook 30 and the mounting base 422 for applying a torsion force to the hook 30 to drive the hook end 302 to rotate away from the second lever 26 .
[0030] Referring also to FIGS. 7 and 8 , an assembly of a portable computer 50 and the locking device 10 is illustrated. The portable computer 50 defines two hook holes 502 at its bottom. Each of the hook holes 502 conforms to the hook 30 and is defined as an L-shaped for the hook 30 to engage in. Before the portable computer 50 is loaded onto the locking device 10 , the detecting pin 362 of the second positioning portion 36 is at a released state, and most of the detecting pin 362 extends out from the case 40 . When the portable computer 50 is placed on the case 40 , the detecting pin 362 is pressed to move along a direction contrary to the first direction Z, and retracts into the case 40 . The hook ends 302 of the hooks 30 are rotated to insert into the hook holes 502 by pressures applied via corresponding edges of the hook holes 502 . The portable computer 50 can thus be locked to the case 40 by the hook 30 . During this time, the first rack 344 of the first positioning portion 34 and the second rack 366 of the second positioning portion 36 continuously separate from each other, and the linkage module 23 stays at its original position.
[0031] When a removal of the portable computer 50 is desired, the release button 21 is pressed along the direction contrary to the first direction Z. The first inclined surface 226 of the pressing post 224 is driven to press the second inclined surface 242 of the first lever 24 . The first lever 24 is thus driven to move along the direction contrary to the second direction Y due to a guidance of the two first posts 412 . At the same time, the first spring 27 is compressed to store potential energy. The third inclined surface of the first lever 24 presses the fourth inclined surface 262 of the second lever 26 . The second lever 26 is thus driven to move along the direction contrary to the third direction X due to a guidance of the three second posts 416 . At the same time, the second spring 29 is compressed to store potential energy. The third lever 28 is driven to move along the second direction Y because of engagements between the sliding pin 282 and the traction slots 268 . The hooks 30 are thus driven to rotate about their own pivot ends 304 to so as to allow the hook holes 502 to be blocked because torsion provided by the torsion springs 32 are balanced by the third lever 28 . The first rack 344 of the first positioning portion 34 is blocked by the second rack 366 of the second positioning portion 36 before the detecting pin 362 returns to the released state. The hand (not shown) actuating the release button 21 can be released when the portable computer 50 is removed from the case 40 .
[0032] Referring back to FIGS. 4 , 5 , and also to FIGS. 9A to 9C , detail description of the engagement of the second positioning portion 36 and the first positioning portion 34 is provided as follows. When the detecting pin 362 of the second positioning portion 36 is retracted into the case 40 , the second rack 366 moves downwardly to align the first rack 344 . When the second lever 26 is driven to move along the direction contrary to the third direction X, the first positioning portion 34 moves along with the second lever 26 . When the first rack 344 is driven to contact the second rack 366 , the third spring 35 is compressed to withdraw the first rack 344 into the second concave 272 in order to get out of the way for the second rack 366 . After the first rack 344 passes over the second rack 366 , the third spring is restored to urge the first rack 344 to move toward the second positioning portion 36 . The first rack 344 is thus blocked by the second rack 366 . The second lever 26 is capable of to continually pull the third levers 28 due to the interaction between the sliding posts 282 and the traction slots 268 . The hook ends 302 are driven to release the hook holes 502 because of the pulling force transmitted by the third levers 28 .
[0033] After the portable computer 50 is removed from the case 40 , the fourth spring 37 is released and urges the second positioning portion 36 to move along the first direction Z. The second rack 366 separates from the first rack 344 . The first positioning portion 34 is released. The second lever 26 is urged by the second spring 29 to move along the third direction X. The third levers 28 is thus released and moved along the direction contrary to the second direction Y. The hook 30 is released, and is urged by the torsion spring 32 to reverse the hook end 302 . Finally, the locking device 10 returns to its original state.
[0034] Referring also to FIG. 10 , a docking station 60 employing the locking device 10 is illustrated. The case 40 of the locking device 10 is suitable for being used as a housing 62 of the docking station 60 . The docking station 60 further includes a connecter 64 that passes through an opening 48 defined on the case 40 for transmitting electrical signals.
[0035] In alternative embodiments, the first lever 24 may be omitted since the release button 21 may directly engage with the second lever 26 . The release button 21 may also be positioned in a sidewall of the case 40 in a manner so as to actuate the second lever 26 . The individual release button 21 may be replaced by constructing a handle that is integrated with the second lever 26 . The pair of third levers 28 may be replaced by a structure such a pair of large-size slots defined in the second lever 26 that may be inserted through by the hook 30 . Therefore, the hook 30 can be directly driven to rotate by the second lever 26 . Fixing positions of the first positioning portion 34 and the second positioning portion 36 may be altered. That is, the first positioning portion 34 may be secured to the case 40 or the like, the second positioning portion 36 may be mounted to the second lever 26 .
[0036] The embodiments described herein are merely illustrative of the principles of the present invention. Other arrangements and advantages may be devised by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, the present invention should be deemed not to be limited to the above detailed description, but rather by the spirit and scope of the claims that follow, and their equivalents. | A locking device includes a case defining at least one slot therein, a hook module including at least one hook for passing through the at least one slot, a linkage module includes at least one first lever configured for shifting the at least one hook to move between a locking position and a releasing position, and a positioning module for releasably engaging with the first lever. When the at least one hook is shifted to the releasing position, the first lever is blocked by the positioning module, when the at least one hook is shifted to the locking position, the first lever is released by the positioning module. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of U.S. Ser. No. 09/443,182 filed Nov. 19, 1999 which is a continuation of U.S. Ser. No. 08/995,389 filed Dec. 22, 1997.
FIELD OF THE INVENTION
[0002] The present invention relates to low molecular weight silicone polyether ABA type block copolymers that are useful to imparting a hydrophilic coating to the surface of either woven or non-woven textiles.
BACKGROUND OF THE INVENTION
[0003] Textiles are made from a variety of materials both natural and man made. Natural textiles include cotton, wool, silk, linen and the like while synthetic textiles are derived from various high polymers such as polyesters, polyamides, polyimides, and the various polyolefins, e.g. polyethylene, polypropylene, polybutylene. While polymers are used extensively to make a variety of products ranging from blown and cast films, extruded sheets, injection molded articles, foams, blow molded articles, extruded pipe, monofilaments and non-woven webs many of the polymers used for such materials are hydrophobic. In many cases this property is an advantage.
[0004] There are a number of uses to which polymers may be put where their hydrophobic nature either limits their usefulness or requires some modification. This is particularly true of polyolefins such as polyethylene and polypropylene which are used to manufacture polymeric fabrics which are used in disposable absorbent articles such as diapers, training pants, incontinence products, wipes, feminine care products and the like. These polymeric fabrics are typically non-woven webs prepared by meltblowing, coforming or spunbonding. For uses such as the foregoing these non-woven fabrics need to be wettable. Frequently wettability can be obtained by coating the fabric in some fashion with a treatment solution during or after formation of the fabric web and drying the web.
[0005] Some of the more commonly applied topically applied treatments are nonionic treatments, for example polyethoxylated octylphenols and the condensation products of propylene oxide with propylene glycol. These types of treatments are effective in rendering normally hydrophobic polymeric fabrics wettable or hydrophilic. However, the treatment is readily removed from the fabric, often after only a single exposure to an aqueous liquid.
[0006] There have been several different approaches to increasing the durability of treatments that are topically applied to the surface of a fabric. Among these approaches have been:
[0007] (1) the use of a composition that includes water, a primary treatment, and a co-treatment that functions to wet the fabric with the treatment composition and that provides for a substantially uniform distribution of the primary treatment onto the fabric;
[0008] (2) the use of a treatment, with or without a nonionic co-treatment that is the reaction product of an acid anhydride derivative with a polyhydroxy compound, polyethylene glycol, triethanolamine, a polyhydroxyamine, and certain unsaturated aliphatic sulfo compounds;
[0009] (3) the use of a treatment, with or without a nonionic co-treatment that is the reaction product of certain unsaturated aliphatic sulfo compounds with the reaction product of an acid anhydride derivative with a polyamine having at least one NH group capable of addition to a double bond;
[0010] (4) the use of a treatment mixture that includes an ester acid, ester salt, or a mixture thereof, and an amide-acid, amide-salt or mixture thereof with or without a nonionic co-treatment;
[0011] (5) the use of a treatment mixture that includes a sorbitol succinate treatment and a co-wetting aid that can be a silicone polyether or a primary or secondary alcohol; and
[0012] (6) the use of a silicone polyether treatment having the formula:
[0013] where R 1 and R 6 are selected from the group of hydrogen and C 1-8 alkyl and aryl, R 2 , R 3 , R 4 and R 5 are selected from the group of C 1-8 alkyl and aryl, the subscript a represents an integer ranging from about 8 to about 25, the subscript b represents an integer ranging from about 8 to about 25, the ratio of b to a is in a range of from about 0.7 to about 1.5, the subscript c represents an integer from 1 to about 10, the subscript d represents an integer of from about 40 to about 70 the ratio of d to two times the sum of a and b is in a range of from about 0.7 to about 1.5 and the number average molecular weight is preferably in a range of from about 5,000 to about 35,000, more preferably from about 6,500 to about 18,500 and most preferably about 7,000.
[0014] The examples of U.S. Pat. No. 5,540,984 ('984) teach that silicone polyether treatments having a molecular weight below about 7,000 do not provide the durability provided by patentee's invention. Further, the polyether endgroups on the silicone treatments employed by the '984 patent ranged from about 50 to 80 weight percent propylene oxide and from about 50 to about 20 weight percent ethylene oxide. The '984 patent specifically teaches that reversing this weight ratio of polyether end groups to 85 weight percent ethylene oxide and 15 weight percent propylene oxide (patentee's example P) does not provide a durable hydrophilic coating as defined by patentee. This is emphasized by patentee's results for a silicone polyether treatment having 100 weight per cent ethylene oxide polyether groups wherein the treatment was not durable (patentee's example J). Thus, the '984 patent teaches that the polyether substituents of the silicone polyether treatment must contain a mix of ethylene oxide and propylene oxide groups or preferably all propylene oxide groups. These results were obtained for copolymers terminated with the respective polyether moieties.
[0015] Notwithstanding the advances that have been made in rendering fabrics wettable by providing for a hydrophilic coating there remains a need for further improvement in these areas.
SUMMARY OF THE INVENTION
[0016] The present invention provides for a treatment silicone compound selected from the group consisting of:
[0017] 1) polysiloxane polyethers having the formula:
[0018] where R 1 is selected from the group consisting of hydrogen and alkyls and R 2 and R 3 are each independently selected from the group consisting of one to forty carbon atom monovalent hydrocarbon radicals; the subscript a ranges from about 1 to about 8; the subscript b ranges from about 1 to about 10; the subscript c ranges from zero to 2; the subscript d ranges from about to 1 to about 10; and the number average molecular weight ranging from ranges from about to 300 to about 1,000.
[0019] 2) polysiloxane polyethers having the formula:
[0020] where R 1 is selected from the group consisting of hydrogen and alkyls and R 2 and R 3 are each independently selected from the group consisting of one to forty carbon atom monovalent hydrocarbon radicals; the subscript a ranges from about to 1 to about 8; the subscript b ranges from about 1 to about 10; the subscript c ranges from zero to 2; the subscript d ranges from about to 1 to about 10; and the number average molecular weight ranging from ranges from about to 300 to about 1,000;
[0021] 3) polysiloxane polyethers having the formula:
[0022] where R 1 is selected from the group consisting of hydrogen and alkyls and R 2 and R 3 are each independently selected from the group consisting of one to forty carbon atom monovalent hydrocarbon radicals; the subscript a ranges from about to 1 to about 8; the subscript b ranges from about 1 to about 10; the subscript c ranges from zero to 2; the subscript d ranges from about to 1 to about 10; the subscript e ranges from about to 1 to about 10; and the number average molecular weight ranging from ranges from about to 300 to about 1,000; and
[0023] 4) mixtures thereof.
[0024] Such treatment silicone compositions are useful for treating fabrics comprised of natural or synthetic polymeric materials to render the fabrics hydrophilic, i.e. capable of picking up and absorbing quantities of water. Such treatment silicone compositions are useful for treating cellulosic materials such as paper.
DETAILED DESCRIPTION OF THE INVENTION
[0025] As used herein, the term “polymeric fabric” means a fabric prepared from any polymeric material capable of being formed into a fabric and includes fabric webs such as paper. Thus, such material can be synthetic or natural, although the former are more likely to be employed in the present invention. Examples of natural polymeric materials include, cotton, silk, wool, and cellulose, by way of illustration only. Synthetic polymeric materials, in turn, can be either thermosetting or thermoplastic materials, with thermoplastic materials being more common. As used herein fabric means any textile, non-woven or woven, or any web such as paper or felt.
[0026] Examples of thermosetting polymers include, by way of illustration only, alkyd resins, such as phthalic anhydride-glycerol resins, maleic acid-glycerol resins, adipic acid-glycerol resins, and phthalic anhydride-pentaerythritol resins; allylic resins, in which such monomers as diallyl phthalate, diallyl isophthalate diallyl maleate, and diallyl chlorendate serve as nonvolatile cross-linking agents in polyester compounds; amino resins, such as aniline-formaldehyde resins, ethylene urea-formaldehyde resins, dicyandiamide-formaldehyde resins, melamine-formaldehyde resins, sulfonamide-formaldehyde resins, and urea-formaldehyde resins; epoxy resins, such as cross-linked epichlorohydrin-bisphenol A resins; phenolic resins, such as phenol-formaldehyde resins, including Novalacs and resols; and thermosetting polyesters, silicones, and urethanes.
[0027] Examples of thermoplastic polymers include, by way of illustration only, end-capped polyacetals, such as poly(oxymethylene) or polyformaldehyde, poly(trichloroacetaldehyde), poly(n-valeraldehyde), poly(acetaldehyde), poly(propionaldehyde), and the like; acrylic polymers, such as polyacrylamide, poly(acrylic acid), poly(methacrylic acid), poly(ethyl acrylate), poly(methyl methacrylate), and the like; fluorocarbon polymers, such as poly(tetrafluoroethylene), perfluorinated ethylene-propylene copolymers, ethylene-tetrafluoroethylene copolymers, poly(chlorotrifluoroethylene), ethylene-chlorotrifluoroethylene copolymers, poly(vinylidene fluoride), poly(vinyl fluoride), and the like; polyamides, such as poly(6-aminocaproic acid) or poly( epsilon-caprolactam), poly(hexamethylene adipamide), poly(hexamethylene sebacamide), poly(11-amino-undecanoic acid), and the like; polyaramides, such as poly(imino-1,3-phenyleneiminoisophthaloyl) or poly(m-phenylene isophthalamide), and the like; parylenes, such as poly-p-xylylene, poly(chloro-p-xylylene), and the like; polyaryl ethers, such as poly(oxy-2,6-dimethyl-1,4-phenylene) or poly(p-phenylene oxide), and the like; polyaryl sulfones, such as poly(oxy-1,4-phenylenesulfonyl-1,4-phenyleneoxy-1,4-phenylene-isopropylidene-1,4-phenylene), poly(sulfonyl-1,4-phenyleneoxyl,4-phenylenesulfonyl-4,4′-biphenylene), and the like; polycarbonates, such as poly(bisphenolA)orpoly(carbonyldioxy-1,4-phenyleneisopropylidene-1,4-phenylene), and the like; polyesters, such as poly(ethylene terephthalate), poly(tetramethylene terephthalate), poly(cyclohexylene-1,4-dimethylene terephthalate) or poly(oxymethylene-1,4-cyclohexylenemethyleneoxyterephthaloyl), and the like; polyaryl sulfides, such as poly(p-phenylene sulfide) or poly(thio-1,4-phenylene), and the like; polyimides, such as poly(pyromellitimido-1,4-phenylene), and the like; polyolefins, such as polyethylene, polypropylene, poly(1-butene), poly(2-butene), poly(1-pentene), poly(2-pentene), poly(3-methyl-1-pentene), poly(4-methyl-1-pentene), 1,2-poly-1,3-butadiene, 1,4-poly-1,3-butadiene, polyisoprene, polychloroprene, polyacrylonitrile, poly(vinyl acetate), poly(vinylidene chloride), polystyrene, and the like: copolymers of the foregoing, such as acrylonitrile-butadiene-styrene (ABS) copolymers, and the like; and the like. In certain embodiments, the polymeric fabric will be prepared from a polyolefin. In other embodiments, the polyolefin will be polypropylene or polyethylene.
[0028] The term “fabric” is used broadly herein to mean any fibrous material which has been formed into a sheet or web. That is, the fabric is composed, at least in part, of fibers of any length. Thus, the fabric can be a woven or nonwoven sheet or web, all of which are readily prepared by methods well-known to those having ordinary skill in the art. For example, nonwoven webs are prepared by such processes as meltblowing, coforming, spunbonding, carding, air laying, and wet laying. Moreover, the fabric can consist of a single layer or multiple layers. In addition, a multilayered fabric can include films, scrim, and other nonfibrous materials.
[0029] As used herein, the term “durable” means that the polymeric fabric to which a treatment has been applied can be subjected to the rigorous washing procedure described hereinafter or to multiple exposures to water and remain wettable.
[0030] The term “treatment” is used herein to mean any active agent that is capable of durably rendering a polymeric fabric (i.e. a fabric either woven or non-woven made from a polymeric fiber) wettable. In some embodiments, the treatment is a linear polysiloxane that is terminated at each end by a polyether moiety derived from ethylene oxide, commonly referred to as an A-B-A polymer. In one embodiment, the treatment is a polysiloxane polyether having the general formula:
[0031] where R 1 is selected from the group consisting of hydrogen and alkyls and R 2 and R 3 are each independently selected from the group consisting of one to forty carbon atom monovalent hydrocarbon radicals; the subscript a ranges from about to 1 to about 8, preferably from about to 1.5 to about 6, more preferably from about to 1.5 to about 5, and most preferably from about to 1.5 to about 4; the subscript b ranges from about 1 to about 10, preferably from about 1 to about 7, more preferably from about 1 to about 5, and most preferably from about to 1 to about 3; the subscript c ranges from zero to 2, more preferably from 1 to 2, and is most preferably 2; the subscript d ranges from about to 1 to about 10, preferably from about to 2 to about 8, more preferably from about to 2 to about 7, and most preferably from about to 3 to about 5; and the number average molecular weight ranging from ranges from about to 300 to about 1,000, preferably from about to 400 to about 900, more preferably from about to 500 to about 900, and most preferably from about to 600 to about 800.
[0032] In a second embodiment, the treatment is a polysiloxane polyether having the general formula:
[0033] where R 1 is selected from the group consisting of hydrogen and alkyls and R 2 and R 3 are each independently selected from the group consisting of one to forty carbon atom monovalent hydrocarbon radicals; the subscript a ranges from about to 1 to about 8, preferably from about to 1.5 to about 6, more preferably from about to 1.5 to about 5, and most preferably from about to 1.5 to about 4; the subscript b ranges from about 1 to about 10, preferably from about 1 to about 7, more preferably from about 1 to about 5, and most preferably from about to 1 to about 3; the subscript c ranges from zero to 2, more preferably from 1 to 2, and is most preferably 2; the subscript d ranges from about to 1 to about 10, preferably from about to 2 to about 8, more preferably from about to 2 to about 7, and most preferably from about to 3 to about 5; and the number average molecular weight ranging from ranges from about to 300 to about 1,000, preferably from about to 400 to about 900, more preferably from about to 500 to about 900, and most preferably from about to 600 to about 800.
[0034] In a third embodiment, the treatment is a polysiloxane polyether having the general formula:
[0035] where R 1 is selected from the group consisting of hydrogen and alkyls and R 2 and R 3 are each independently selected from the group consisting of one to forty carbon atom monovalent hydrocarbon radicals; the subscript a ranges from about to 1 to about 8, preferably from about to 1.5 to about 6, more preferably from about to 1.5 to about 5, and most preferably from about to 1.5 to about 4; the subscript b ranges from about 1 to about 10, preferably from about 1 to about 7, more preferably from about 1 to about 5, and most preferably from about to 1 to about 3 ; the subscript c ranges from zero to 2, more preferably from 1 to 2, and is most preferably 2; the subscript d ranges from about to 1 to about 10, preferably from about to 2 to about 8, more preferably from about to 2 to about 7, and most preferably from about to 3 to about 5; the subscript e ranges from about to 1 to about 10, preferably from about to 2 to about 8, more preferably from about to 2 to about 7, and most preferably from about to 3 to about 5; and the number average molecular weight ranging from ranges from about to 300 to about 1,000, preferably from about to 400 to about 900, more preferably from about to 500 to about 900, and most preferably from about to 600 to about 800.
[0036] In a fourth embodiment the treatment of the present invention is a mixture comprising two or more of the first, second and third embodiments. It should be noted that for molecular species the subscripts a, b, c, d etc. will assume integral values. When a mixture of compounds is employed as the treatment component, the values of the subscripts will assume non-integral values depending on the population fraction for a given molecular weight, i.e. molar averaged stoichiometric subscripts will be non-integral in the case of mixtures as opposed to pure compounds.
[0037] The advantages of the present invention are that the silicone polyether compounds of the present invention do not require a co-treatment. The materials also are effective at extremely low levels and maintain effectiveness after as many as five washings. Thus the materials maintain effectiveness after one, two, three, four and five washings. Effectiveness as to the hydrophilic coating is defined in the experimental section.
[0038] The hydrophilic coatings or treatments of the present invention typically comprise from about 0.01 to about 20.00 weight percent of the total weight of the treated fabric, preferably from about 0.10 to about 10.00 weight percent of the total weight of the treated fabric, more preferably from about 0.50 to about 5.00 weight percent of the total weight of the treated fabric, and most preferably from about 0.75 to about 2.50weight percent of the total weight of the treated fabric.
[0039] Depending on the means employed to coat the fabric, the coated fabric may demonstrate a greater or lesser hydrophilic behavior for a given treatment composition depending on whether the coating is applied from an aqueous solution or dispersion or an alcoholic solution or dispersion. The greatest hydrophilic behavior is observed when the hydrophilic coating is applied from an aqueous dispersion, particularly when water is the only solvent employed. Textiles treated by the treatment of the present invention are useful for disposable absorbent articles such as diapers, training pants, incontinence products, wipes, feminine care products and the like. Wipes may be personal care wipes, floor care wipes, household care wipes, automotive care wipes and the like. In one embodiment, the treatment of the present invention, heretofore referred to as a coating, which coating may be a partial coating or a complete coating, involves depositing the treating agent, the compounds used in the present invention, onto the textile or fabric being treated to render it hydrophilic, preferably durably hydrophilic.
[0040] All U.S. patents referenced herein are specifically herewith and hereby incorporated by reference.
[0041] The following experiments are to be regarded as illustrative only and are not intended by their presentation to constitute any limitations upon the appended claims.
EXPERIMENTAL
[0042] The base fabric used in evaluating the coating compositions of the present invention was a spunbound polypropylene nonwoven web having a basis weight of 15.5 g per square meter. The fabric was cut into test swatches having dimensions of 22±5 cm×28±5 cm and an average weight ranging from 0.9 to 1.1 g (1.00±0.10 g). The silicone polyether compounds evaluated had the following structural formulas:
[0043] The silicone polyether compounds evaluated for the purposes of the present invention are listed in Table 1.
TABLE 1 Structural Parameters for Silicone Polyethers Sample No. Type R 1 R 2 R 3 a b c d e 1 A H CH 3 CH 3 1.8 3 2 3 0 2 A H CH 3 CH 3 4 3 2 0 0 3 A H CH 3 CH 3 4 3 2 3 0 4 A H CH 3 CH 3 4 3 2 4 0 5 A H CH 3 CH 3 4 3 2 5 0 6 A H CH 3 CH 3 8 3 2 3 0 7 A H CH 3 CH 3 8 3 2 5 0 8 A H CH 3 CH 3 8 3 2 10 0 9 A H CH 3 CH 3 12 3 2 15 0 10 A H CH 3 CH 3 20 3 2 25 0 11 B H CH 3 CH 3 1.7 3 2 3 0 12 C H CH 3 CH 3 12 3 3 20 3
[0044] The silicone polyethers listed in Table 1 were suspended or dissolved in a 50 weight percent aqueous solution of isopropanol (2-propanol) or water at levels of 2.0, 0.5, 0.4 and 0.1 weight percent. Samples of the nonwoven spunbonded polypropylene fabric were treated by soaking them in the water-alcohol-silicone polyether mixture for 1-2 hours followed by drying in a forced air oven for 30 minutes at 105° C. The treated fabrics, having swatch dimensions of 22×28 cm. and weighing on average 0.95 g each were tested for hydrophilicity by pouring 100 g of water onto the fabric samples while the fabric sample was supported at a 35° angle above horizontal with an absorbent pad directly underneath the sample, which is known in the art as a run-off test. The absorbent pad was obtained by placing ten layers of commercially available paper towels one on top of each other; the paper towels having essentially the same dimensions as the fabric test swatch. Any of the water that ran off the fabric and was not absorbed was collected and measured. The treated fabric was judged effective or as having an effective hydrophilic coating if the fabric swatch and the absorbent pad thereunder retained 80 g of the 100 g poured onto the fabric, i.e. 80%. Conversely, if 20 g of water or more was recovered from the test the fabric sample was deemed to have failed the test. Fabrics that were treated with a water solution or dispersion of the compounds of the present invention tended to perform better than fabrics treated with alcoholic solutions or dispersions. The amount of coating it is possible to impart to the treated fabric tends to be a function of how the fabric is treated, i.e. whether the external surfaces of the fabric are treated or whether the entire fabric is immersed into the impregnating solution or dispersion.
TABLE 2 Coating Weights of Hydrophilic Silicone Coating on Textile Samples Solution Concentra- Concentra- tion of Sample tion of Aqueous iso- Coating Weight No. A D Silicone, wt. % Pr-OH of Silicone, wt. % A-1 1.8 3 0.05 0 4.67 A-3 4 3 2.00 50 6.59 A-3 4 3 0.50 50 0.66 A-3 4 3 0.40 50 1.20 A-3 4 3 0.40 0 15.03 A-3 4 3 0.30 0 6.88 A-3 4 3 0.20 0 4.64 A-3 4 3 0.10 0 1.75 A-3 4 3 0.05 0 1.68 A-5 4 5 2.00 50 8.01 A-5 4 5 0.50 50 1.30 A-5 4 5 0.05 0 1.25 A-6 8 3 0.05 0 0 A-7 8 5 2.00 50 3.44 A-8 8 10 2.00 50 3.78 A-8 8 10 0.05 28 0 A-9 12 15 0.05 28 0 A-10 20 25 0.05 28 0.02 B-1 1.7 2 2.00 50 9.01 B-1 1.7 3 0.50 50 1.31 C-1 8 1 0.05 0 0 C-2 12 3 2.00 50 5.39 C-2 12 3 0.05 28 0.05
[0045] The coated textiles when coated with the compounds of the present invention will pick up varying amounts of water depending on how extensively the textile is treated. If only the external surfaces of the textile are treated at very low levels, the total amount of water absorbed by the treated textile will be very low and may be indistinguishable from an untreated fabric. However, if the entire body of the fabric, exterior and interior, has been treated, the treated fabric can absorb as much as 300 to 400 weight percent. | Low molecular weight silicone polyether ABA type block copolymer treatments wherein a linear polysiloxane is terminated at each end by a polyether moiety derived from ethylene oxide are useful to imparting a hydrophilic coating to the surface of either woven or non-woven textiles. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on Provisional Application U.S. Ser. No. 60/995,191 filed Sep. 25, 2007.
FIELD OF THE INVENTION
[0002] The present invention relates to a four stage steam reformer suitable for producing a synthetic gaseous stream from a feedstock comprised of a carbonaceous material. Each stage is capable of operating at a progressively higher temperature than the immediate preceding stage.
BACKGROUND OF THE INVENTION
[0003] The steam reforming of carbonaceous materials into carbon oxides and hydrogen is the heart of synthesis gas plants, particularly hydrogen-rich gas plants. The technology has been known for many decades and new developments are continually being made, both in equipment and related catalyst technology. Steam reforming technologies can generally be distinguished by the type of heat input. Such technologies include adiabatic (prereforming), convection heat transfer, radiant heat transfer (side fired tubular reformer), and internal combustion (autothermal reformer).
[0004] Until recently most steam reforming technology was used for reforming methane to produce methanol. There has been substantial activity in recent years in the field of biofuels, such as the production of ethanol from a biomass, such as corn. There is also interest in producing ethanol and ethylene from coal using a steam reformer as disclosed in co-pending U.S. Patent Application filed concurrent with this application and having an attorney docket number of 196353, and based on U.S. Provisional Application 60/995,192 which was filed Sep. 25, 2007 and which is incorporated herein by reference.
[0005] While conventional reformer technology has met with a commercial success for converting biomass to synthetic gas, there are problems associated with effectively converting such feedstocks to synthetic gas without undesirable side reactions occurring. Therefore, there is a need in the art for improved steam reforming technology to accommodate complex biomass feedstocks.
SUMMARY OF THE INVENTION
[0006] In accordance with the present invention there is provided a four stage steam reformer comprising:
[0007] a) a first reactor vessel comprised of an enclosing wall thereby defining an enclosure, a first inlet to the interior of said enclosure, a first outlet leading out of said interior of said enclosure, an tubular arrangement having a first end and a second end and secured within said interior of said enclosure which first end is fluidly connected to an inlet port of said enclosing wall and said second end fluidly connected to an outlet port of said enclosing wall;
[0008] b) a second stage reactor vessel fluidly connected to said outlet port of said enclosing wall of said first stage reactor vessel at an inlet which is comprised of a plurality of flow divider tubes and which is secured to the underside of said second stage reactor vessel which is cylindrical in shape and wherein each divider tube is fluidly connected to a reaction tube that extends vertically throughout said second reactor vessel and further extending through a top plate of said second reactor vessel;
[0009] c) a third stage reactor vessel which is cylindrical in shape and which contains a plurality of vertically oriented reaction tubes each fluidly connected to a vertically oriented reactor tube of said second reactor vessel and extending through a bottom plate of said third reactor vessel, which third reactor vessel contains a burner at its bottom for providing heat to all of stage 1 , stage 2 and stage 3 reaction vessels;
[0010] d) a manifold having a inlet and an outlet wherein said inlet is in fluid communication with the plurality of reactor tubes extending through the bottom of said third reactor vessel whose outlet is a single port;
[0011] e) a fourth stage reactor vessel which is cylindrical in shape and which has a first inlet in fluid communication with said outlet port of said manifold and a second inlet which is in fluid communication with said first inlet, which fourth stage reactor vessel also contains a an outlet port for exhausting flue gas and an outlet for removing solids.
BRIEF DESCRIPTION OF THE FIGURES
[0012] FIG. 1 hereof is a schematic of a preferred four stage reformer of the present invention.
[0013] FIG. 2 hereof is a view, along plane A-A, of the stages 1 and 2 of the reformer system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring to FIG. 1 hereof, there is shown a four stage steam reformer reactor system of the present invention for reforming a carbonaceous material feedstock to produce a synthesis gas. The term “carbonaceous material” is a material that is rich in carbon such as hydrocarbons, coal-based products, and petroleum-based products. The term “hydrocarbon” as used herein includes materials typically also referred to as “hydrocarbonaceous”, which materials are comprised primarily of hydrogen, carbon and oxygen, but which also contains other elements as well such as the heteroatoms oxygen, sulfur and nitrogen. Non-limiting examples of feedstocks suitable for use with the four stage reformer reactor system of the present invention include coal, oil-shale, and biomass. Non-limiting examples of biomass materials suitable for use herein include corn, molasses, agricultural waste, forest residue, municipal solid waste, and energy crops. Agricultural waste includes crop residues such as wheat straw, corn stover (leaves, stalks, and cobs), rice straw, and bagasse (sugar cane waste). Forestry residue includes underutilized wood and logging residues, rough, rotten, and salvable dead wood; and excess saplings and small trees. Municipal solid waste contains some cellulosic materials, such as paper. Energy crops, developed and grown specifically for fuel include fast-growing trees, shrubs, and grasses such as hybrid poplars, willows, and switchgrass. Preferred biomass materials include corn and blackstrap molasses. Blackstrap molasses is a thick syrup by-product obtained from the processing of sugarcane or sugar beet into sugar.
[0015] FIG. 1 shows the four stages as separate reactor vessels each in fluid communication with the next downstream and upstream vessel. By four stages we mean four temperature stages in series with each stage operated at a higher temperature than the immediate preceeding stage. By downstream we mean with respect to the direction that a feedstock will progress through the series of reactor vessels from the first stage to the fourth stage. The fourth stage preferably has the ability to switch out with an autothermal type of stage for treating feedstock having a very low reactivity and requiring extremely high conversion temperatures. A suitable feedstock is introduced via line 10 into mixing zone M along with an effective amount steam, preferably superheated steam, that is introduced via line 12 . Any suitable feedstock can be used in the practice of the present invention. Non-limiting examples of types of hydrocarbon feedstocks that can be used include any of the coals, from lignite to anthracite; cellulosic materials, preferably wood; agricultural products, preferably corn; alcohols, preferably methanol; and alkanes, preferably methane, butane and propane. The mixture is divided into a predetermined number of feed streams, depending primarily on the type of feedstock and the size of the reactor vessels. The feed mixture is conducted via line 14 from mixing zone M to flow divider FD. Flow dividers are well known to those having at least ordinary skill in the art and thus there is no need to discuss them in detail herein. Each stream is conducted via feed tubes a-f to inlet ports IP on the side of the reactor vessel V 1 . It is preferred that all reactor vessels of this invention be cylindrical in shape. All construction materials, including reactor vessels and reactor tubes through which the feedstock passes through the four stages are manufactured from high temperature alloys suitable for the temperatures and conditions of the particular reactor vessel in which they are located. It is preferred that the reactor tubes be cast tubes comprised of a high temperature alloy. It has been found by the inventor hereof that cast alloy feed tubes are able to withstand the environment of the reactor vessels of the present invention better than extruded or rolled tubes. Therefore, cast feed tubes are preferred.
[0016] The divided feedstreams are transported through reactor vessel V 1 through feed tubes and are fluidly connected to outlet ports OP which are fluidly connected to feed tubes within the interior of reactor vessel V 1 . In fact, all individual feed tubes are fluidly connected from the flow divider FD to manifold MF. Reactor vessel V 1 is preferably a shell and tube type vessel and will be run during the stream reforming reaction at a temperature from about 650° F. to about 800° F. The heat used to run reactor vessel V 1 is derived from flue gas stream FGS that originates in stage 3 reactor vessel V 3 by burner B which is fueled via line 16 preferably with natural gas, or a portion of the synthesis gas produced in the apparatus of the present invention. Feed tubes exit reactor vessel V 1 at outlet ports OP and are fluidly connected to inlet ports at the bottom of stage 2 reactor vessel V 2 which are fluidly connected to a plurality of feed tubes extending vertically throughout the length of reactor vessel V 2 . Reactor vessel V 2 will be operated in the temperature range of about 1300° F. to about 1450° F. The heat to run reactor vessel V 2 is also obtained from the flue gas stream FGS produced by burner B located at the bottom of reactor vessel V 3 . In the event flue gas stream FGS does not provide an adequate amount of heat to maintain reactor vessel at a temperature from about 1300° F. to about 1450° F. trim burner 18 may be used to add heat to flue gas stream FGS. It is preferred that trim burner 18 also be fueled by use of natural gas or a portion of the product synthesis gas stream. It is also preferred that the trim burner be an annular shaped burner situated on the perimeter of the opening of flue gas pipe FGP which is fluidly connected to the top of reactor vessel V 2 to receive flue gas from reactor vessel V 3 .
[0017] The reaction product of reactor vessel V 2 continues flowing downstream through a plurality of feed tubes that fluidly connect vertically oriented feed tubes in reactor vessel V 2 and the plurality of feed tubes vertically oriented in reactor vessel V 3 . Reactor vessel V 3 is operated at a temperature in the range of about 1450° F. to about 1750° F. where further reaction of the hydrocarbons in the reaction product from V 2 takes place. An insulating top, or cover, IT is provided that encloses the tops of reactor vessels V 2 and V 3 to prevent an undesirable amount of heat loss from feed tubes extending from reactor vessel V 2 to V 3 . The tubular members exit the bottom the reactor vessel V 3 and into manifold MF where the reaction product streams are combined and exit manifold MF via line 20 . If a feedstock, such as natural gas or methanol, is used and the steam reforming reaction is completed in reactor vessel V 3 , the product synthesis gas can be collected and stored or sent for further downstream processing. If the hydrocarbon feedstock is relatively refractory and contains a high carbon content, such as anthracite, then the reaction product exiting manifold MF is sent via line 22 to a fourth stage reactor vessel V 4 by first conducting it to a mixer 26 where it is mixed with an effective amount of an oxygen-containing gas, preferably substantially pure oxygen via line 24 . It will be understood that mixer 26 can be either external or internal to reactor vessel V 4 . It is preferred that it be external. The mixture of reaction product from reactor vessel V 3 and oxygen-containing gas enter reactor vessel V 4 at 28 where it further combusts at temperatures from about 1750° F. to about 2100° F., preferably at a temperature from about 1800° F. to about 2000° F. The final reaction product synthesis gas exits the four stage steam reformer at outlet 32 and is collected and stored, or transported off site, or passed to a downstream process unit for further processing. Such further processing can include syn gas clean-up technology as described in U.S. Pat. No. 7,375,142 which is incorporated herein by reference to produce a clean product that can be used to further process into synthetic natural gas, alcohols, and hydrocarbons.
[0018] FIG. 2 hereof is a cross-sectional view along A-A of FIG. 1 hereof showing base plates BP 2 and BP 3 for reactor vessels V 2 and V 3 respectively. Also shown reactively for each reactor vessels V 2 and V 3 are outside walls W 2 and W 3 and tubular members a, b c, d, e, and f. Tubular members a, b, c, d, e, and f extend vertically upward from base plate BP 2 and to reactor vessel R 3 where they extend vertically downward to based plate BP 3 . FL is the flame from burner B. | A four stage steam reformer suitable for producing a synthetic gaseous stream from a carbonaceous feedstock. Each stage is capable of operating at a progressively higher temperature than the immediate preceding stage. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Korean Patent Application No. 2003-39679, filed on Jun. 19, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a linear compressor and more particularly a linear compressor having an improved assembling structure of an inner core assembly.
2. Description of the Related Art
In general, a conventional linear compressor comprises a casing, a mover provided in the casing and reciprocating by an interaction of an inner core and an outer core, a compressing part compressing and discharging a refrigerant, and a linear motor generating a, driving force of the inner and outer cores.
The conventional linear compressor operates in the following sequence.
When power is supplied to the compressor while the compressor is in a stop state, current is applied to winding coils at an opening part of the outer core, thereby generating a rotational magnetic flux at the inner core and the outer core. The magnetic flux interacts with a magnetic field formed by a magnet to reciprocate a piston, and thereby suctioning and discharging the refrigerant after compressing.
Korean Patent No. 0374837 discloses a linear motor for such a conventional compressor comprising a stator having an outer core and a cylindrical inner core inserted into the outer core, winding coils combined into the inner core or the outer core, and a mover movably inserted between the outer core and the inner core having a permanent magnet provided therein.
The outer core includes a plurality of lamination sheets incorporated into a laminated unit, and is combined to an annular bobbin having coils wounded by an injection-molded insulator.
However, it is necessary that the inner core and the outer core provided as a laminated unit are firmly mounted with a simple structure and an easy installation, and thereby reducing the manufacturing costs of the conventional linear motor.
Also, it is necessary to prevent a decrease in the efficiency of the linear motor due to an eddy current loss generated when material having low electrical resistivity for the inner core of the conventional linear motor.
SUMMARY OF THE INVENTION
Accordingly, it is an aspect of the present invention to provide a linear compressor which is capable of simplifying an inner core assembly, thereby reducing the manufacturing cost.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part, will be obvious from the description, or may be learned by practice of the invention.
The foregoing and/or other aspects of the present invention are achieved by providing a linear compressor comprising an external casing forming a compressing chamber, an outer core disposed in the external casing, an inner core assembly disposed inside of the outer core interacting with the outer core, wherein the inner core assembly comprising an inner core, an upper cover combined to an upper part of the inner core, and a bottom supporting part combined to a bottom part of the inner core.
According to an aspect of the invention, the inner core comprising a plurality of core blocks provided by stacking a plurality of core steel plates made by punching thin steel plates, wherein the plurality of core blocks are circumferentially arranged around the inner core at regular intervals.
According to an aspect of the invention, each core steel plate comprising an upper hook in an upper part thereof, and a bottom hook in a bottom part, and the upper cover comprising an upper recess to engage with the upper hook and the bottom supporting part comprising a bottom recess to engage with the bottom hook.
According to an aspect of the invention, the upper cover and the bottom supporting part are connected to each other by a connection member, which stands erect toward the bottom supporting part.
According to an aspect of the invention, the connection member comprising a bolt or a rivet disposed between the plurality of core blocks.
According to an aspect of the invention, the upper cover and the bottom supporting part are provided as a single unit, and the plurality of core blocks have connection supporting parts standing erect toward the bottom supporting part between the core blocks, forming a single unit with the upper cover and the bottom supporting part.
According to an aspect of the invention, the inner core is made by stacking a plurality of core steel plates made by punching thin steel plates.
According to an aspect of the invention, the upper part of each of the core steel plates comprising an upper hook protruding upward, and the bottom supporting part of each of the core steel plates has a bottom hook protruding downward, and the upper cover comprising an upper recess to engage with the upper hook and the bottom supporting part has a bottom recess to engage with the bottom hook, wherein an area where the upper hook is engaged with the upper recess, and an area where the bottom hook is engaged with the bottom recess are welded to each other.
BRIEF DESCRIPTION OF THE DRAWINGS
These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a sectional view of a linear compressor according to a first embodiment of the present invention;
FIG. 2 is a plan view of an inner core assembly of the linear compressor of FIG. 1 ;
FIG. 3 a sectional view of the inner core assembly, taken along a line III-III of FIG. 2 ;
FIG. 4 is a plan view of the inner core assembly shown in FIG. 2 , without an upper cover;
FIG. 5 is a plan view of the inner core assembly according to a second embodiment of the present invention;
FIG. 6 is a sectional view of an inner core assembly, taken along a line VI-VI of FIG. 5 ;
FIG. 7 is a plan view of an inner core assembly according to a third embodiment of the present invention;
FIG. 8 is a sectional view of the inner core assembly, taken along a line VIII-VIII of FIG. 7 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.
In FIG. 1 , a linear compressor according to a first embodiment of the present invention comprising an external casing 10 , a mover 20 provided in the external casing 10 and reciprocating by an interaction of an outer core 40 (to be described later) and an inner core 61 (to be described later), and a compressing part 30 suctioning and discharging the refrigerant after compressing.
The external casing 10 is closed to the outside with an upper casing 11 and a bottom casing 12 welded to each other at an end of the upper casing 11 and an end of the bottom casing 12 . In FIG. 1 , the end of the bottom casing 12 is welded on the end of the upper casing 11 .
The mover 20 comprising a main frame 22 , an inner core assembly 60 disposed inside the main frame 22 , and a cylinder-shaped magnet 26 disposed in an opening of the inner core assembly 60 . An inner core 61 of the inner core assembly 60 is radially disposed to the inner circumference of the main frame 22 .
In FIGS. 2-4 , the inner core assembly 60 has the cylinder-shaped inner core 61 , an upper cover 70 combined to an upper side of the inner core 61 , a bottom supporting part 80 combined to a bottom of the inner core 61 . The upper cover 70 is combined with the bottom supporting part 80 by at least one connection member 90 . The inner core 61 comprising a plurality of core blocks 62 radially arranged at regular intervals to form a cylinder shape. Each of the core blocks 62 is formed by stacking a plurality of core steel plates 63 made by punching a thin steel plate and welding the stack of core steel plates 63 .
In upper parts of the plurality of core steel plates 63 forming the core blocks 62 , upper hooks 64 are protruded upward to be combined to the upper cover 70 , and bottom hooks 65 are protruded downward to be combined to the bottom supporting part 80 in a bottom of the plurality of core steel plates 63 .
An upper recess 71 is formed in an upper part of the inner core 61 to engage with the upper hooks 64 , to combine the upper cover 70 to the upper part of the inner core 61 . Thus, the upper cover 70 can support the upper part of the inner core 61 .
In the upper cover 70 , a plurality of first connecting holes 72 are circumferentially arranged around the inner core 61 .
A bottom recess 81 is formed in a bottom of the inner core 61 engaged with the bottom hooks 65 and to combine the bottom supporting part 80 to the bottom of the inner core 61 .
In the bottom supporting part 80 , a plurality of second connecting holes 82 are circumferentially arranged around the inner core 61 wherein the connection member 90 connecting the upper cover 70 and the bottom supporting part 80 is engaged.
The connection member 90 comprising a bolt or a rivet, and passing through the first connecting hole 72 of the upper cover 70 and through a space formed between the plurality of core blocks 62 , and is then inserted into the second connecting hole 82 of the bottom supporting part 80 . Thus, the upper cover 70 and the bottom supporting part 80 are stably connected. Here, the connection member 90 is vertically positioned to the bottom supporting part 80 .
In FIG. 1 the compressing part 30 comprising a cylinder block 34 forming a compressing chamber 32 while supporting a bottom of the outer core 40 , a piston 36 reciprocating in the compressing chamber 32 , and a cylinder head 38 provided in a bottom area of the cylinder block 34 and having valves for a refrigerant.
The cylinder-shaped outer core 40 is provided on an outside the mover 20 , with a predetermined gap relative to the magnet 26 . An opening of the outer core 40 comprising a plurality of core steel plates (not shown) stacked each having annular coils 42 therein.
The outer core 40 comprising a bottom part supported by the cylinder block 34 and an upper part supported by a supporting block 44 . On an upper part of the supporting block 44 , a resonant spring (not shown) accelerating the reciprocating movement of the piston 36 is combined by a plurality of shaft members 52 .
The linear compressor according to the present invention is operated as follows.
When power is supplied to the linear compressor in a stop state, current is applied to the coils 42 in the opening of the outer core 40 . Then, a rotational magnetic flux is generated in the outer core 40 and the inner core 61 to thereby generate magnetic flux to interact with a magnetic field of the magnet 26 . Thus, the piston reciprocates up and down so as to suction, compress and discharge the refrigerant of the compressing chamber 32 .
According to the first embodiment of the present invention, the upper cover 70 and the bottom supporting part 80 are individually provided and connected to each other by at least one connection member 90 . According to a second embodiment as shown in FIGS. 5 and 6 , the upper cover 70 and the bottom supporting part 80 is provided as a single unit by injection molding of resin or die casting of aluminum. Accordingly, unlike the connection member 90 provided between the plurality of the core blocks 62 according to the first embodiment of the present invention, connection supporting parts 95 are provided between the plurality of the core blocks 62 a in a vertical direction to a bottom supporting part 80 a as shown in FIG. 5 , forming a single unit with an upper cover 70 a and the bottom supporting part 80 a.
The inner core 61 a comprises the plurality of core blocks 62 and 62 a according to the first and the second embodiments of the present invention. In FIGS. 7 and 8 , an inner core 61 b can be made by radially stacking core steel plates 63 a made by punching thin steel plates with an upper cover 70 b combined to an upper part of the inner core 61 b and a bottom supporting part 80 b combined to a bottom part thereof. That is, as parts of the inner core 61 b , an upper hook 64 b formed in the plurality of core steel plates 63 a and an upper recess 71 b of the upper cover 70 b are engaged to each other, and thus the upper cover 70 b is connected to the upper part of the inner core 61 b , and a bottom hook 65 b formed in a plurality of the core steel plates 63 a and a bottom recess 81 b are engaged to each other, so that the bottom supporting part 80 b is connected to the bottom part of the inner core 61 b.
According to a third embodiment of the present invention, connecting areas of the upper hook 64 b and the upper recess 71 b and of the bottom hook 65 b and the bottom recess 81 b are respectively welded, unlike the first and second embodiments.
In the linear compressor according to the third embodiment of the present invention, the inner core assembly can be manufactured simply, thereby decreasing the manufacturing cost.
Also, the inner core assembly with such an assembling structure minimizes eddy current, thereby increasing the efficiency of the linear motor.
Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. | A linear compressor comprises an external casing forming a compressing chamber, an outer core disposed in the external casing, an inner core assembly disposed inside of the outer core interacting with the outer core, and wherein the inner core assembly comprises an inner core, an upper cover combined to an upper part of the inner core, and a bottom supporting part combined to a bottom part of the inner core. With this configuration, the linear compressor provides a capability of simplifying an inner core assembly, thereby reducing the manufacturing cost. | 5 |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
This patent application claims the benefit of U.S. Provisional Patent Application No. 60/569,074, filed May 7, 2004, which is incorporated by reference. In addition, this application claims the benefit of European Application No. 04101760.9 filed Apr. 27, 2004, which is also incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to radiography, computed radiography as well as digital radiography.
The invention more particularly relates to a method and a system for associating data such as identification data of a patient and/or data relating to an x-ray exposure with a radiographic image.
BACKGROUND OF THE INVENTION
In addition to classical radiography systems in which a radiographic image of a patient is recorded on radiographic hard copy film, computed radiography systems based on storage phosphor technology are nowadays commonly used.
In such a computed radiography system a cassette conveying a photo-stimulable phosphor screen is exposed to a radiation image of a body part of a patient.
All kinds of data to be associated with the image such as demographic data (patient name, gender, date of birth etc.) and data relating to the exposure such as mAs, kV etc. are entered in a workstation or are retrieved from a hospital information system or a radiology information system.
These data are then transferred onto an identification means which is coupled with the cassette. For example the data are written into an EPROM device which is provided on the cassette conveying the exposed phosphor screen or the data are transferred via radio-frequency transmission to a radio-frequency tag provided on the cassette.
The identified cassette conveying an exposed photo-stimulable phosphor screen is then fed into a read out apparatus (also referred to as a ‘digitizer’) where the identification data are read from the identification means and where the radiographic image which is stored in the phosphor screen is read out. The radiographic image is read out by scanning the exposed photo-stimulable phosphor screen with stimulating radiation and by converting the image-wise modulated light which is emitted by the screen upon stimulation into a digital signal representation of the radiographic image.
A radiographic study often comprises more than one radiographic image. For example a study of a hand comprises two or three images on different cassettes.
In such a case several cassettes each containing a photo-stimulable phosphor screen are exposed to a radiation image of the patient in different positions or to different body parts of the patient. Commonly the individual images part of a study are taken in sequence. Then the exposed cassettes are taken to the identification station where identification of the individual images is performed.
Alternatively identification of all cassettes is performed prior to exposure.
It is clear that this procedure might result in erroneous identification because different data are to be associated with exposed cassettes which contain different images but which on the outer side are indistinguishable.
It is also possible that the data which are associated with the cassette correspond with the intended circumstances, for example the intended or default settings of the X-ray source but which, due to various possible circumstances do not exactly represent the effectively applied radiation data.
Information and complaint studies have learnt that the identification procedure in radiology departments in which cassette based systems are used, is experienced as complex and error prone during every step of the workflow.
Still another problem is that there is no feed back to the operator whether the cassette intending for exposure has been properly erased and is thus free from image information before a new exposure is performed.
It is thus clear that correct association of all kinds of identification and exposure related data as well as feedback on the status of the screen within a cassette is a crucial part within the workflow of a radiology department which influences the efficiency of operations within the radiography department.
Apart from computed radiography systems digital radiography systems are gaining importance. In such a system a digital radiography detector such as a Cmos based x-ray detector is exposed to a radiation image and a digital signal representation of the image is directly generated. The signal can then be applied to a hard copy recorder, a work station or a picture archiving system (PACS). Also in this type of systems adequate and error proof association of identification and exposure data and feedback of the status of the detector (exposed, ready for exposure etc.) is required.
It is an aspect of the present invention to provide a method and apparatus that overcomes the above-mentioned problems associated with the prior art workflow.
SUMMARY OF THE INVENTION
The above-mentioned aspects are realized by a method as set out in claim 1 .
Another aspect of the invention relates to a system as set out in the appending claims. The system comprises a workstation arranged for entering patient identification data and/or exposure related data, a radiation detector, an electronic identification means coupled with said detector and a source of radiation provided with a reader/writer device arranged for communicating said data or a code uniquely identifying said data with said workstation and with said electronic identification means.
The radiation detector for example comprises a photo-stimulable phosphor screen or a digital radiography detector.
An example of an electronic identification means is a radio-frequency tag or the like enabling data communication from and towards the identification station (occasionally via the intermediary of a reader/writer device coupled to the source of radiation).
Specific features for preferred embodiments of the invention are set out in the dependent claims.
Further advantages and embodiments of the present invention will become apparent from the following description.
DETAILED DESCRIPTION OF THE INVENTION
While the present invention will hereinafter be described in connection with preferred embodiments thereof, it will be understood that it is not intended to limit the invention to those embodiments.
A first embodiment relates to a computed radiography system in which an x-ray image is recorded on a photo-stimulable phosphor screen conveyed in a cassette.
Identification data pertaining to the patient and/or exposure settings are entered in an identification station which is a workstation running an identification software.
More specifically these data are demographic data and exposure-related data such as patient's name, examination type, sub-examination type, exposure settings etc.
Alternatively these data are retrieved from a hospital information system or a radiology information system.
An erased cassette is positioned—for example in a bucky—in an adequate position for exposure to an x-ray image of a patient body part. The cassette comprises a radio-frequency tag such as has been described in European patent application EP 727 696.
Preferably prior to exposure feedback is provided from the cassette to the identification station on the status of the cassette: erased or non-erased.
It is possible to make the subsequent work flow dependent on the communicated status, e.g. to disable exposure of a non-erased cassette.
Next the source of radiation is activated in accordance with the settings entered in the identification station and the photo-stimulable phosphor screen is exposed to a radiation image of a body part of the patient.
During or short after exposure, in any case between the moment when the first action initiating the exposure is performed and the moment on which the radiation source and the detector can again be relatively displaced (shortly after exposure) the final data which were entered into the identification station are transferred to the tag on the cassette conveying the photo-stimulable phosphor screen. In other words these data are transferred to the tag on the cassette while it is in the exposure position.
Data transfer is preferably performed from identification station to cassette through the intermediary of a reader/writer mounted on or coupled to the radiation tube (for example be integrated in the collimator).
In this way correct identification data and actual exposure data are transferred to the cassette conveying the phosphor screen on which the image is to be recorded to which these data pertain so that erroneous identification or erroneous association of data and images are eliminated.
The above-described reader/writer is for example a reader writer based on Psion Tektronic technology or the like.
The transfer of data from the identification station (also called modality workstation) to the reader could be based on an explicit and/or exposure command.
It can either be achieved in a wireless way or via cable connection. The information by the reader towards a tag provided on the exposed cassette is a wire-less transfer.
The effective data can be transferred. However, in an alternative embodiment a code pertaining to the effective data can be transferred.
The cassette which now carries the radiation image as well as the exposure and identification data or a code pertaining to these data can then be removed from its position (e.g. from the bucky) and can be transferred to a read out apparatus where the image is read out and a digital representation is obtained and where also the data from the identification tag are read.
In this work flow image data and identification and exposure data are automatically associated with each other so that errors or wrong association of image and respective data are eliminated.
The digital signal representation of the radiation image and the identification and exposure data can then be applied to a hard copy recorder, a work station and/or archive station etc.
The above-described procedure relates to a computed radiography system based on a photo-stimulable phosphor screen detector.
In an alternative embodiment the detector is a digital radiography detector comprising a radiation sensor such as a sensor based on Cmos, Selenium or CCD technology or the like.
The above-described way of transferring data to the cassette in both the computed radiography and the digital radiography system ensures correct mapping or association of all data in the X-ray room pertaining to the patient and the exposure without an additional cassette identification step added to the work flow which would decrease the speed of operation. | Patient identification data and/or exposure related data or a code uniquely identifying at least one of these data is transferred shortly before or during exposure to a radio-frequency tag or the like coupled to a radiation detector. Transfer may be executed through the intermediary of a reader/writer coupled to a source of radiation. | 0 |
BACKGROUND OF THE INVENTION
In the past and currently, large quantities of insulating paper containing asbestos are wrapped around internal combustion engine exhaust system components, principally mufflers, to provide thermal and acoustic insulation. However, various authorities now believe that the dust created in the handling of asbestos materials may be hazardous. It is very difficult in the mass manufacture of exhaust system components for use in automobiles, trucks, etc., to completely eliminate the possibility that in cutting or handling asbestos paper some of it will be released into the air. Likewise, if failure of exhaust system components occurs after usage, asbestos may be released into the air.
BRIEF SUMMARY OF THE INVENTION
In view of the objection to the use of asbestos on the ground that it is potentially hazardous to health, it is the purpose of this invention to provide an exhaust system component for internal combustion engines which is insulated by means of a material that does not contain asbestos. The invention accomplishes this purpose by the use of a special mat consisting essentially of a specific type of glass fibers properly sized and bound together.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross section (with parts rotated into the plane of the drawing to facilitate illustration) through a typical exhaust system component in the form of an automotive muffler which embodies the invention;
FIG. 2 is an end elevation taken from the right of FIG. 1;
FIG. 3 is an enlarged cross section taken along the line 3--3 of FIG. 2; and
FIG. 4 is a typical cross section through a small piece of mat used in practicing the invention.
DESCRIPTION OF THE INVENTION
A typical automotive muffler 1 embodying the invention is illustrated in the drawings and is intended to illustrate an exhaust system component, which may also be a converter, conduit, etc. The muffler 1 has a housing 3 which includes an oval shaped tubular shell 5 which is closed at its upstream end by an inlet header 7 and at its downstream end by an outlet header 9, the periphery of each header being interlocked in a typical roll seam joint 11 with an adjacent end of the shell 5. The shell 5 is formed from an initially rectangular piece of sheet steel that is shaped into tubular form and its longitudinal side edges 13 are interlocked in a longitudinal lock seam 15 projecting inwardly with respect to the outer surface of the shell 5 as seen in FIG. 2.
The inside of the shell 5 contains a pair of longitudinally spaced transverse partitions 17 and 19 which have circumferential flanges that are spot welded to the shell 5 as indicated by the designation "X" in the drawings. These partitions subdivide the space inside of the shell 5 into the three chambers 21, 23, and 25. The partition 17 has three annular necks 27, 29, and 31 which are aligned respectively with three necks 33, 35, and 37 that are formed in the partition 19. An inlet tube 39 is supported inside of the aligned necks 27 and 33, being spot welded to neck 33 as indicated by the designation "X;" an outlet tube 41 is supported in the aligned necks 29 and 35; and an intermediate, return flow tube 43 is supported in the necks 31 and 37. An inlet bushing 45 and an outlet bushing 47 are supported in and spot welded to annular necks 49 and 51 formed respectively in the inlet and outlet headers 7 and 9. The inlet bushing 45 extends through and is supported in the neck 27, and supports the upstream end of the inlet gas flow tube 39. The inner end of the outlet bushing 47 extends through and is supported in the neck 35 of header 19 that is an alignment with the neck 51 and serves to receive and support the downstream end of the outlet gas flow tube 41.
The inlet tube 39 has a pair of louver patches 53 that are surrounded by a closed tubular shell 55 that is shaped to provide closed chambers 57 into which the louvers of the patches 53 open to provide acoustic communication between the tube 39 and the chambers 57.
Similarly, the outlet tube 41 has a closed shell 59 mounted on it to provide a closed chamber into which the louvers of a louver patch 61 open to provide a spit chamber attenuation system for the outlet tube. In addition, the outlet tube 41 has a louver patch 63 opening into the chamber 23 and the return flow tube 43 has a louver patch 65 also opening into the chamber 23.
In operation as a muffler to attenuate sound in an internal combustion engine exhaust system, gas enters the muffler 1 through the inlet bushing 45 and flows down the inlet tube 39 into the crossover chamber 25. High frequency noises and roughness are attenuated by the dual spit chamber arrangement 55 and lower frequencies by flow of gas into and through the relatively large chamber 25. The gas in the chamber 25 enters the end 67, which projects into the chamber, of the return flow tube 43 and goes in a reverse direction toward the upstream end of the muffler to enter the crossover chamber 21. The acoustic connection provided by the louver patch 65 with the chamber 23 attenuates intermediate and high frequency sound and the abrupt changes in diameter as the gas flows from chamber 25 into chamber 21 produce significant sound attenuation. The gas in the chamber 21 enters the outlet tube 41 and in flowing by the louver patch 63 has communication with the chamber 23 so that sound attenuation can occur as well as come bypass flow from the louver patch 65. As the gas passes the spit chamber 59, higher frequencies and roughness are attenuated and thereafter the gas enters the outlet bushing 47 to flow downstream in the exhaust system.
The parts so far described are made of metal, usually sheet steel, and therefore have a relatively high thermal conductivity. An insulating layer 69 held in place by an outer layer of metal 71 is wrapped around the exterior of the shell 5 and held in place by the longitudinal side edges of the metal 71 which are interlocked together as seen at 73. Prior to wrapping, the insulating layer 69 is preferably a rectangular piece of material and after wrapping it functions to reduce the heat loss to the surrounding environment, lower the external temperature of the muffler, and also to dampen vibrations of the shell 5, i.e. attenuates shell noise.
As mentioned above, it has been the practice to use an asbestos-based paper for the layer 69. In accordance with the present invention, a material that contains no asbestos is used as a replacement for asbestos-based paper. The material used is similar to asbestos paper in that it is available in sheet or roll form and has a similar stiffness and mechanical strength, but it is substantially more resilient; and it is at least substantially equivalent to asbestos paper with respect to thermal insulation, noise damping, and durability.
The material used in practicing the invention is a wet-laid glass fiber mat in sheet or roll form of substantially uniform nominal thickness and of substantially homogeneous composition. It has a basis weight (i.e. pounds/3000 sq. ft.) in the range of 65-150 pounds, is composed of borosilicate glass fibers of grades D-E (i.e. 5.08-7.62 microns fiber diameter) having a preferable glass fiber length of about 1/4" to 1/2", and an average caliper (thickness) per ASTM test D645 of 0.020 to 0.100 inches. About 80% of the fibers should be at least 1/4" in length and preferably the 80% of the fibers which are at least 1/4" in length would be between 1/4" and about 1/2" in length. The glass fibers are physically intermingled in a random orientation in the process of making the mat to provide a relatively high degree of mat integrity and resistance to disintegration. The mat generally contains no filler and the only other ingredient besides glass fibers is a binder that is dispersed so as to eliminate loose fibers on either surface of the material. The binder is preferably a polyvinyl alcohol resin in the amount of about 2-5% by weight of the mat. Thus, glass fibers constitute about 95-98% of the weight of the mat in the ready to use condition. The mat has a tensile strength per ASTM test D828 in the machine direction of about 3.5-5.0 pounds/inch of width and in the cross machine direction of about 2.5-4.0 pounds/inch of width. The required tensile strength is a function of both basis weight and caliper, e.g. with a nominal basis weight of 65 pounds and caliper of 0.050 inch the tensile strength in the machine direction is 3.5 pounds per inch of width and the cross machine direction is 2.5 pounds per inch of width while with a nominal basis weight of 130 pounds and caliper of 0.100 inch the tensile strength in the machine direction would be about 5.0 pounds per inch of width and the cross machine direction would be about 4.0 pounds per inch of width. Materials meeting these various specifications are commercially available.
Referring to FIG. 4, generally these mats, such as mat 79, are produced on a modified Four drinier machine and have a wire side 80 and a side 81 opposite the wire side. Wire side 80 is typically, as shown, flat or planar. Side 81 is produced with a very irregular or random undulating or stucco like appearing surface having high portions 82 and low portions 83.
In a typical mat the low portions 83 and the high portions 82 of the mat may deviate from the nominal thickness of the mat by 20-30% of the nominal thickness of the mat. For example, if the mat 79 shown in FIG. 4 has a caliper of 0.040 inch, the distance between wire side 80 and low portions 83 will bypically be in the order of 0.030 inch and the distance between the wire side 80 and the high portions 82 would typically be about 0.050 inch.
In assembly, the flat surface 80 is preferably placed in contact with the cover 71 when the latter is flat and then the combination is wrapped around the shell 5 and the cover lockseamed as at 73. Having the flat surface 80 in contact with the cover metal increases the friction between the two and facilitates assembly. On the other hand, the undulated surface 81 is in contact with the shell 5, which is the source of heat and sound, and while there is less surface contact area with the mat, there is a greatly increased absorbent surface area due to the undulations. Due to the much greater resiliency of the fiberglass mat than that of asbestos, the cover 71 can be wrapped tighter (i.e. the layer 69 compressed to a substantially greater extent) which translates into a cover 71 that has a somewhat less wrap-around length than for an asbestos layer and therefore uses less metal and is of reduced weight.
The space present between adjacent high portions 82 is occupied by air which is of thermal and accoustic insulative value when such mats are placed in an exhaust system component. Additonally, the undulating contour of side 81 increases the volume occupied by mat 79, for a given amount of material. This increase in volume increases the economic and the resource efficiency of such mats as less material is required for a given application and less weight is added to the exhaust system component. Weight reduction of vehicle components is very important at the present time to increase the energy efficiency of motor vehicles.
Investigation to date indicates that one or two layers of 0.030" embossed asbestos paper (0.018 paper embossed to 0.030 overall thickness) may be satisfactorily replaced as a muffler or resonator wrap 69 by one layer of the present material which is of a nominal 65 pound (range 60-70) basis weight and nominal 0.050 inch (range 0.045-0.055) caliper with a weight reduction, respectively, calculated to be about 76% and 88% of the weight of the asbestos; and that three such layers of asbestos may be satisfactorily replaced by two layers of the just mentioned basis weight and caliper or by one layer of the present fiber glass mat having a nominal basis weight of 130 (range 123-137) and nominal caliper of 0.100 (range 0.090-0.100) with a weight reduction calculated to be about 84%. It is believed that similar substitutions can be made on pipes or conduits, laminated Y-pipes or joints, catalytic converters, and other exhaust system components.
Modifications may be made in the specific structure that has been described and illustrated without departing from the spirit and scope of the invention. | A fiberglass mat of a particular formulation is used to insulate exhaust system components such as mufflers, converters, and conduits. | 5 |
This is a continuation of application Ser. No. 188,570, filed Oct. 12, 1971, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to imaging systems, and more particularly, to improved electrostatographic developing materials, their manufacture and use.
The formation and development of images on the surface of photoconductive materials by electrostatic means is well known. The basic electrophotographic process, as taught by C. F. Carlson in U.S. Pat. No. 2,297,691, involves placing a uniform electrostatic charge on a photoconductive insulating layer, exposing the layer to a light and shadow image to dissipate the charge on the areas of the layers exposed to the light and developing the resulting electrostatic latent image by depositing on the image a finely divided electroscopic material referred to in the art as "toner". The toner will normally be attracted to those areas of the layer which retain a charge thereby forming a toner image corresponding to the electrostatic latent image. This powder image may then be transferred to a support surface such as paper. The transferred image may substantially be permanently affixed to the support surface as by heat. Instead of latent image formation by uniformly charging the photoconductive layer and then exposing the layer to a light and shadow image, one may form the latent image by directly charging the layer in image configuration. The powder image may be fixed to the photoconductive layer if the powder image transfer step is not desired. Other suitable fixing means such as solvent or overcoating treatment may be substituted for the foregoing heat fixing step.
Several methods are known for applying the electroscopic particles to the electrostatic latent image to be developed. One development method, as disclosed by E. N. Wise in U.S. Pat. No. 2,618,552, is known as "cascade" development. In this method, a developer material comprising relatively large carrier particles having finely divided toner particles electrostatically coated thereon is conveyed to and rolled or cascaded across the electrostatic image bearing surface. The composition of the carrier particles is so selected as to triboelectrically charge the toner particles to their desired polarity. As the mixture cascades or rolls across the latent image bearing surface, the toner particles are electrostatically deposited and secured in positive development processes to the charged portion of the latent image and are not deposited on the uncharged or background portions of the image. Most of the toner particles accidentally deposited in the background areas are removed by the rolling carrier, due apparently, to the greater electrostatic attraction between the toner and the carrier than between the toner and the discharged background. The carrier and excess toner are then recycled. This technique is extremely good for development of line copy images.
Another method for developing electrostatic images is the "magnetic brush" process as disclosed, for example, in U.S. Pat. No. 2,874,063. In this method, a developer material containing toner particles and magnetically attractable carrier particles are carried by a magnet. The magnetic field of the magnet causes alignment of the magnetically attractable carrier particles into a brushlike configuration. This magnetic brush is engaged with the electrostatic image bearing surface and the toner particles are drawn from the brush to the latent image by electrostatic attraction.
Still another technique for developing electrostatic latent images is the "powder cloud" process as disclosed, for example, by C. F. Carlson in U.S. Pat. No. 2,221,776. In this method, a developer material comprising electrically charged toner particles in a gaseous fluid is passed adjacent the surface bearing the electrostatic latent image. The toner particles are drawn by electrostatic attraction from the gas to the latent image. This process is particularly useful in continuous tone development.
Other development methods such as "touchdown" development as disclosed by R. W. Gundlach in U.S. Pat. No. 3,166,432 may be used where suitable.
Generally, commercial electrostatographic development systems utilize automatic machines. Since automatic electrostatographic imaging machines should operate with a minimum of maintenance, the developer employed in the machines should be capable of being recycled through many thousands of cycles. In automatic xerographic equipment, it is conventional to employ an electrophotographic plate which is charged, exposed and then developed by contact with a developer mixture. In some automatic machines, the toner image formed on the electrophotographic plate is transferred to a receiving surface and the electrophotographic plate is then cleaned for reuse. Transfer is effected by a corona generating device which imparts an electrostatic charge to attract the powder from the electrophotographic plate to the recording surface. The polarity of charge required to effect image transfer is dependent upon the visual form of the original copy relative to the reproduction and to the electroscopic characteristics of the developing material employed to effect development. For example, where a positive reproduction is to be made of the positive original, it is conventional to employ a positive corona to effect transfer of a negatively charged toner image to the recording surface. When a positive reproduction from a negative original is desired, it is conventional to employ positively charged toner which is repelled by the charged areas on the plate to the discharged areas thereon to form a positive image which may be transferred by negative polarity corona. In either case, a residual powder image usually remains on the image after transfer. Because the plate may be reused for a subsequent cycle, it is necessary that the residual image be removed to prevent "ghost images" from forming on subsequent copies and toner film from forming on the photoreceptor surface. In a positive to positive reproduction process described above, the residual powder is tightly retained on the plate surface by a phenomenon not fully understood which prevents complete transfer of the powder to the support surface, particularly in the image area. Incomplete transfer of toner particles is undesirable because image density of the ultimate copy is reduced and highly abrasive photoreceptor cleaning techniques are required to remove the residual toner from the photoreceptor surface. This imaging process is ordinarily repeated for each copy reproduced by the machine any time during the reusable life of the developer and the electrophotographic plate surface.
Various electrostatographic plate cleaning devices such as the "brush" and the "web" cleaning apparatus are known in the prior art. A typical brush cleaning apparatus is disclosed by L. E. Walkup et al, in U.S. Pat. No. 2,832,977. The brush type cleaning means usually comprises one or more rotating brushes, which remove residual powder from the plate into a stream of air which is exhausted through a filtering system. A typical web cleaning device is disclosed by W. E. Graff, Jr. et al in U.S. Pat. No. 3,186,838. As disclosed by Graff, Jr. et al., removal of the residual powder on the plate is effected by passing a web of fibrous materials over the plate surface. Another system for removing residual toner particles from the surface of a photoreceptor comprises a flexible cleaning blade which wipes or scrapes the residual toner from the photoreceptor surface as the surface moves past the blade.
Unfortunately, the foregoing cleaning systems do not effectively remove all types of toner particles from all types of reusable photoreceptors. This is not a shortcoming of the cleaning system, but a shortcoming of particular toners used in conjunction with particular photoreceptors. If a particular toner would not tend to form an adherent residual film on a particular photoreceptor, the cleaning systems described would effectively remove all residual toner. However, many commercial toners of their very nature do tend to form a residual film on reusable photoreceptors. The formation of such films is undesirable because it adversely affects the quality of undeveloped and developed images. The toner film problem of these particular toners is acute in high speed copying and duplicating machines where contact between the developer and the imaging surface occurs a great many more times and at a higher velocity than in conventional electrostatographic systems. Ultimately, the toner buildup becomes so great that effective copying or duplicating is impaired. As a result, more stringent means, e.g. solvent removal, are necessary to remove this type of film. Frequent shutdown of the apparatus, in order to clean the surface of the photoreceptor is obviously undesirable since the machine is taken out of commission and repeated techniques of this type wear down the photoreceptor surface.
Thus, there is a continuing need for a technique for eliminating the buildup of toner film on the surface of a photoreceptor. Electrostatographic systems and, in particular, the imaging, developing and cleaning aspects of such systems would be significantly advanced if the foregoing problems were effectively overcome.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a developer composition which effectively eliminates toner film buildup.
It is another object of the invention to provide a developer composition which improves solid area print density.
It is a further object of the invention to provide a developer composition which reduces background density of copies.
It is yet another object of the invention to provide a developer composition having enhanced and stabilized triboelectric characteristics.
It is still another object of the invention to provide a developer composition which permits effective long term prevention or control of toner filming on a reusable photoreceptor.
A still further object of the invention is to provide a developer composition of increased life, i.e., more prints per unit weight of developer.
Still another object of the invention is to provide a developer composition which yields copies of comparatively high optical density.
It is another object of the invention to provide a process which prevents undesirable buildup of developer components on reusable electrostatographic imaging surfaces.
It is a further object of this invention to provide an electrostatographic imaging process employing developing materials which provides for more effective cleaning of reusable electrostatographic imaging surfaces.
It is another object of this invention to provide an electrostatographic imaging process employing developer mixtures which are readily transferable from an electrostatographic surface to a transfer surface.
A further object of the invention is to provide an improved developer composition and process which yields images and copy with no loss of resolution.
Yet a further object is to provide an improved developer composition and process with no loss in fusing efficiency.
A still further object of the invention is to provide an improved developer composition having less tendency for toner blocking.
A further object of the invention is to provide an improved developer composition which increases the life of imaging surface cleaning members.
The above objects and others are accomplished by providing an electrostatographic developing material comprising particles, said particles including (1) a finely divided, electroscopic, toner material; (2) a minor proportion based on the weight of said toner of a finely divided solid frictionreducing material having a hardness less than said toner material and having greater friction-reducing characteristics than said toner material, said friction-reducing material having a greater tendency than said toner material of forming a thin, adherent film deposit on a surface when applied from a mixture of said materials with a shearing force; and (3) a minor proportion based on the weight of said toner material of a finely divided abrasive material of a hardness greater than said frictionreducing and toner materials.
Thus, the developer composition of the present invention comprises three constituents, a toner material and a dual additive comprising a friction-reducing material and a finely divided abrasive type material.
Other objects of the invention are accomplished through a cyclic imaging and development process comprising forming an electrostatic latent image on an imaging surface and forming a developed image by contacting said imaging surface with an electrostatographic developing mixture comprising particles, said particles including (1) finely divided electroscopic toner material, (2) a minor proportion based on the weight of said toner of a finely divided, solid, friction-reducing material having a hardness less than said toner material and having greater friction-reducing characteristics than said toner material, said friction-reducing material having a greater tendency than said toner material of forming a thin, adherent film deposit on a surface when applied from a mixture of said materials with a shearing force; and (3) a minor proportion based on the weight of said toner material of a finely divided, nonsmearable, abrasive material of a hardness greater than said frictionreducing and toner materials; removing at least a portion of at least any residual developed image from said imaging surface by a force which causes the developer mixture to be wiped across at least a portion of said imaging surface; and repeating the process sequence at least one additional time.
The toner material of the present invention may be any electroscopic toner material which preferably is pigmented or dyed. Typical toner materials include polystyrene resin, acrylic resin, polyethylene resin, polyvinyl chloride resin, polyacrylamide resin, methacrylate resin, polyethylene terephthalate resin, polyamide resin, and copolymers, polyblends and mixtures thereof. Vinyl resins having a melting point or melting range starting at least about 110°F are especially suitable for use in the toner of this invention. These vinyl resins may be a homopolymer or a copolymer of two or more vinyl monomers. Typical monomeric units which may be employed to form vinyl polymers include: styrene, vinyl naphthalene, mono-olefins, such as, ethylene, propylene, butylene, isobutylene and the like, vinyl esters, such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butryrate and the like, esters of alphamethylene aliphatic monocarboxylic acids such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate dodecyl acrylate, n-octyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and the like; vinyl ethers such as vinyl methyl ether, vinyl isobutyl ether, vinyl ethyl ether, and the like; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone and the like; and mixtures thereof. Suitable materials employed as the toner will usually have an average molecular weight between about 3,000 to about 500,000.
Any suitable pigment or dye may be employed as the colorant for the toner particles. Toner colorants are well known and include, for example, carbon black, nigrosine dye, aniline blue, Calco Oil Blue, chrome yellow, ultramarine blue, duPont Oil Red, quinoline yellow, methylene blue chloride, phthalocyanine blue, Malachite Green Oxalate, lamp black, Rose Bengal and mixtures thereof. The pigment or dyes should be present in the toner in a sufficient quantity to render it highly colored so that it will form a clearly visible image on a recording member. Thus, for example, where conventional xerographic copies of typed documents are desired, the toner may comprise a black pigment such as carbon black or a black dye such as Amaplast Black Dye available from the National Aniline Products, Incorporated. Preferably, the pigment is employed in an amount of from about 1% to about 30%, by weight, based on the total weight of the colored toner. If the toner colorant employed is a dye, substantially smaller quantities of the colorant may be used.
When the toner materials of the present invention are to be employed in the aforementioned development processes, the toner should have an average particle size less than about 30 microns.
The solid lubricating or friction-reducing additive of the present invention is a material which is capable of forming a thin, adherent film deposit on the imaging surface of a reusable photoreceptor during the repeating cycles of an electrostatographic system. This material need not be one which will form a completely continuous film on the imaging surface, although many will form a continuous film. Other friction-reducing materials will tend to fill the valleys of the surface and minute peaks will be coated with no more than a monolayer of the friction-reducing material. This material must have characteristics which permit its deposition on an imaging surface more easily than the toner material employed. The hardness of the friction-reducing material is undoubtedly related to the ability of this additive to form a deposit or film on the imaging surface. Thus, the friction-reducing material must be softer than the selected toner material. Any of the suitable standard hardness tests can be employed in determining whether or not a selected friction-reducing material is softer than a selected toner material. For example, using the Shore Durometer A, B, C or D Hardness scales, following the technique of ASTM D-1706, any material having a hardness less than that assigned to a selected toner would be effective providing the material has the other characteristics detailed below. The melting point of the friction-reducing additive is limited mainly by the ambient operating conditions and obviously should be at least somewhat higher than the ambient temperature.
The friction-reducing material also must have greater friction-reducing characteristics than the selected toner material. Any dynamic technique can be employed to determine the relative friction-reducing characteristics of the contemplated friction-reducing materials versus contemplated toner materials. In general, the test involves merely comparing the degree of reduction in friction caused by the friction-reducing material versus the toner material when each is placed between two mating surfaces in relative motion. The materials of the mating surfaces should be reasonably flat and each should have a kinetic coefficient of friction greater than that of the friction-reducing material and the toner material.
One technique found to be adequate is as follows: The object of the technique is to traverse a blade of rubberlike material across imaging surfaces which had been buffed with the materials to be tested, followed by a determination of the relative coefficient of friction values of the buffed-on materials.
A blade holder and sled mechanism is employed in conjunction with a base for supporting an imaging surface. The blade is a strip of a commercially available polyurethane, rubberlike material, 11/2 inch long, 1/16 inch thick and 1/2 inch wide. The edge of the strip, which will make contact with the imaging surface, is cut or chamfered at an angle of 60° to the horizontal. The blade will be held with the chamfered region facing away from the direction of traverse of the blade. It will be held at an angle of 22° with respect to the imaging surface in a wiping, rather than chiseling, attitude. The imaging surfaces are selenium coated aluminum plates, 12 × 14 inches in size. The coefficient of friction measurements are made with an Instron Model TM (Instron Corporation, Canton, Massachusetts) attached to the blade holder sled. The force necessary to pull the sled alone is determined and this is subtracted from the force necessary to pull the sled and move the blade across the imaging surface. This results in the kinetic force of friction necessary to pull the blade alone. The normal force of the blade moving along the imaging surface is measured with a force gauge. The kinetic force divided by this value results in a value of the kinetic coefficient of friction.
The coefficient of friction values for as many selenium plates as there are materials to be tested is determined. Any plate having a value deviating from the mean by more than 10% is discarded. Using a different plate and blade for each material to be tested, each plate is buffed in a uniform manner with the material to be tested. Equal weights of material are employed during application of the material to the plates.
In this manner, one skilled in the art can determine the friction-reducing characteristics of selected materials versus contemplated toner materials. Specific examples of materials tested in this manner are given below.
The friction-reducing materials also must have a resistivity high enough not to interfere with the latent image on the imaging surface.
Typical friction-reducing materials having the above defined characteristics include: saturated or unsaturated, substituted or unsubstituted fatty acids, preferably of from 8 to 35 carbon atoms, or metal salts of such fatty acids; fatty alcohols corresponding to said acids; mono and polyhydric alcohol esters of said acids and corresponding amides; polyethylene glycols and methoxy-polyethylene glycols; terephthalic acid; isophthalic acid, 2,5 dimethylterephthalic acid, 2,5 dichloroterephthalic acid, p-phenylene diacrylic acid, anisic acid, terephthaldehyde, metal terephthalates e.g. sodium terephthalate; cholesterol; Dechlorane, i.e. perchloropentacyclodecane polycaprolactones having a molecular weight of about less than 4000, and low molecular weight fluorocarbon compounds such as waxy short chain telomers of tetrafluoroethylene, low molecular weight, smearable polytetrafluorethylene powders, etc. The metal salts of the above identified fatty acids include, but are not limited to, the lithium, sodium, potassium, copper, rubidium, silver, magnesium, calcium, zinc, strontium, cadmium, barium, mercury, aluminum, chromium, tin, titanium, zirconium, lead, manganese, iron, cobalt and nickel salts and mixtures of said salts. Ammonium and substituted ammonium salts of fatty acids are also contemplated. Specific fatty acids contemplated include caprylic, pelargonic, capric, undecanoic, lauric, tridecanoic, myristic, pentadecanoic, palmitic, margaric, stearic, arachidic, behenic, lignoceric, cerotic and mixtures thereof. The corresponding solid fatty alcohols, esters, amides, derivatives thereof and mixtures thereof are contemplated.
Specific mono and polyhydric alcohol esters of fatty acids which are contemplated are derived from C 1 to C 20 alcohols which form esters with fatty acids which are solid under the conditions of contemplated use. For example, methyl, ethyl, propyl, etc., alcohols or alkylene diols and triols of from 2 to 10 carbon atoms at least partially esterified with C 8 -C 35 fatty acids are contemplated. Examples of contemplated esters include: methyl stearate, ethylene glycol monostearate, glyceryl tri-(- 12-hydroxy stearate), 1,2,4-butanetriol tristearate, etc.
The polyethylene glycols and methoxypolyethylene glycols are condensation products known commercially as Carbowaxes. The contemplated Carbowaxes are solid, waxlike materials having a molecular weight of up to about 6000.
When a developer composition containing a friction-reducing material as the additive is employed for general copying purposes, there is noted an excessive buildup of this additive on the imaging surface in somewhat the same fashion as toner without an additive builds up. This buildup is also particularly acute in high speed copying and duplicating machines where contact between the developer and the imaging surface occurs a great many more times and at higher velocities than in conventional electrostatographic systems. It was discovered that the utilization of a comparatively hard, finely divided nonsmearable abrasive material could be employed in conjunction with the friction-reducing material with outstanding success.
With no intention of being bound by any theory of action, it is believed that a friction-reducing material of the type defined, if used as the sole developer additive, forms a lubricating film on an imaging surface more easily and to the essential exclusion of a toner film. This film not only permits more effective removal of residual toner material but also increases the life and efficiency of any cleaning member used to remove residual developer. During use, however, the friction-reducing material will build up to an extent which gradually degrades the quality of copies. By including in the developer composition a minor proportion of a finely divided, nonsmearable mildly abrasive material, this material will control the buildup of the friction-reducing material by its abrasive action when a cleaning means removes residual developer from an imaging surface with a force which causes the developer mixture to be wiped across at least a portion of the imaging surface. This combination of additives permits the friction-reducing material to perform its function while the abrasive material prevents an excessive, interference layer of lubricant from building up. In addition, the proper triboelectric difference between a charging means, e.g. carrier particles, and the toner material is at least stabilized since the abrasive material prevents a nullifying buildup of toner on the charging means.
Contemplated abrasive materials include colloidal silica, surface modified organophilic silica, aluminum silicate, surface treated aluminum silicate, titanium dioxide, alumina, calcium carbonate, antimony trioxide, barium titanate, calcium titanate or strontium titanate, CaSiO 3 , MgO, ZnO, ZrO 2 etc. and mixtures thereof.
The particularly preferred materials are those which have been surface modified to impart hydrophobic characteristics thereto. For example, hydrophobic silicas are prepared by reacting freshly prepared colloidal silica with at least one organosilicon compound having hydrocarbon groups as well as hydrolyzable groups attached to its silicon atom. In one technique, the reactants and steam are pneumatically introduced in parallel flow into a fluidized bed reactor heated to about 400°C. The organosilicon compound reacts with silanol groups on the surface of the SiO 2 particles and chemical attachment between the silicon atom in the organosilicon compound and the silicon atom in the SiO 2 occurs through an oxygen atom. Any suitable hydrocarbon or substituted hydrocarbon organic group directly attached to a silicon atom in the organosilicon compound may be employed in preparing the modified silica. The organic group is preferably one which imparts hydrophobic characteristics to the abrasive material to improve the stability of developer materials under varying humidity conditions. The organic groups may comprise saturated or unsaturated hydrocarbon groups or derivatives thereof. Saturated organic groups include methyl, ethyl, propyl, butyl, chloropropyl and chloromethyl groups. Examples of typical organosilicon compounds include: dimethyl dichlorosilane, trimethyl chlorosilane, methyl trichlorosilane, vinyl triethoxy silane. The type of organo groups can influence the triboelectric characteristics of the developer. For example, aminopropylsilane treated with silica can be used in a reversal type developer.
The particle size of the abrasive additive should fall within the submicron range of from about 1 to about 500 millimicrons and preferably, between about 10 to about 100 millimicrons.
Concerning the comparative hardness of the abrasive type material, this material must be harder than both the toner material and the friction-reducing material. While most of the materials disclosed can be considered to be very hard materials falling within Mohs' hardness scale, it is to be understood that any material of less hardness than talc of Mohs' hardness scale can also be employed so long as it is harder than the toner material and friction-reducing material. Materials softer than talc are conveniently classified according to the Shore durometer penetration technique and placed within either scale A, B, C and D of this test procedure.
The chemical composition of the abrasive additive is not critical so long as it does not introduce deleterious contaminents or adversely affect the imaging and development aspects of an electrostatographic system. In addition, there is no particular criticality surrounding the shape of each abrasive particle since both spherical and irregularly shaped additives function effectively. Preferred materials are Aerosil R972, a hydrophobic silica available from DeGussa Incorporated, New York, New York and Kaophile-2, a hydrophobic aluminum silicate, available from Georgia Kaolin Company, Elizabeth, New Jersey.
The composition of the present invention finds utility in all known electrostatographic development systems. This includes systems which employ a carrier material such as magnetic brush development and cascade development as well as systems which do not necessarily employ a carrier material such as powder cloud development, fiber brush development and touchdown development.
Suitable coated and uncoated carrier materials for cascade development are well known in the art. The carrier particles comprise any suitable solid material, provided that the carrier particles acquire a charge having an opposite polarity to that of the toner particles when brought in contact with the toner particles so that the toner particles cling to and surround the carrier particles. When a positive reproduction of the electrostatic images is desired, the carrier particles are selected so that the toner particles acquire a charge having a polarity opposite to that of the electrostatic image. Alternatively, if a reversal reproduction of the electrostatic image is desired, the carrier is selected so that the toner particles acquire a charge having the same polarity as that of the electrostatic image. Thus, the materials for the carrier particles are selected in accordance with its triboelectric properties in respect to the electroscopic toner so that when mixed or brought into mutual contact, one component of the developer is charged positively if the other component is below the first component in a triboelectric series and negatively if the other component is above the first component in a triboelectric series. By proper selection of materials in accordance with their triboelectric effects, the polarities of their charge, when mixed, are such that the electroscopic toner particles adhere to and are coated on the surface of carrier particles and also adhere to that portion of the electrostatic image bearing surface having a greater attraction for the toner than the carrier particles. Typical carriers include: steel, flintshot, aluminum potassium chloride, Rochelle salt, nickel, potassium chlorate, granular zircon, granular silica, methyl methacrylate, glass and the like. The carriers may be employed with or without a coating. Many of the foregoing and other typical carriers are described in U.S. Pat. No. 2,618,552. An ultimate coated particle diameter between about 50 microns to about 2000 microns is preferred because the carrier particles then possess sufficient density and inertia to avoid adherence to the electrostatic images during the cascade development process. Adherence of carrier beads to electrostatic drums is undesirable because of the formation of deep scratches on the surface during the image transfer and drum cleaning steps. Also, print deletion occurs when large carrier beads adhere to xerographic imaging surfaces. For magnetic brush development, carrier particles having an average particle size less than about 800 microns are satisfactory. Generally speaking, satisfactory results are obtained when about 1 part toner is used with about 10 to about 1000 parts by weight of carrier in the cascade and magnetic brush developers.
Concerning the broad relative proportions of the toner material versus the additive materials, functionally stated, the friction-reducing material should be present in a proportion at least sufficient to form on adherent deposit substantially uniformly distributed over at least 20% of the area of an imaging surface during cyclic use of the imaging surface. It is preferred that approximately 100% of the imaging area becomes coated with the friction-reducing material. It has been found that from about 0.01 to about 10% by weight of friction-reducing material based on the weight of the toner material will achieve the foregoing degree of coverage. A particularly preferred ratio is from about 0.1% to about 2.0% by weight of friction-reducing material based on the weight of toner.
Functionally stated, the abrasive material must be present in a relative proportion sufficient to maintain the thickness of the friction-reducing film deposit within the submicron range i.e. less than 10,000A, in order to avoid having an interference film, yet this proportion must not be so great as to completely remove the deposit or prevent one from forming. If the relative proportion is so great that no film is retained or formed, the mildly abrasive material will be acting directly on the photoreceptor and for long term operation this can contribute to shortening the life of the photoreceptor and certain of the cleaning means employed in the system. As a lower limit, as long as about 5A of the friction-reducing material is available on the imaging surface the benefits of the present invention will be realized. One skilled in the art can readily determine optimum ratios of the dual additives by monitoring the thickness of the residual friction-reducing film. The use of a radioactive tracer in the friction-reducing material is one effective means of optimizing proportions. Comparative long term runs will also be of assistance. Generally, it has been found that from about 0.01% to about 10% by weight of abrasive material based on the weight of the toner material will achieve the desired results. A particularly preferred range is from about 0.1 to about 2% by weight.
The toner compositions of the instant invention may be employed to develop electrostatic latent images on any suitable electrostatic latent image bearing surface including conventional photoconductive surfaces. Well known photoconductive materials include: vitreous selenium, organic or inorganic photoconductors embedded in a nonphotoconductive matrix, organic or inorganic photoconductors embedded in a photoconductive matrix or the like. Representative patents in which photoconductive materials are disclosed include: U.S. Pat. Nos. 2,803,542 to Ullrich; 2,970,906 to Bixby; 3,121,006 to Middleton; 3,121,007 to Middleton and 3,151,982 to Corrsin.
In U.S. Pat. No. 2,986,521, Wielicki, there is taught a reversal type developer powder for electrostatic printing comprising electroscopic material, i.e. toner, coated with a finely divided colloidal silica. The toner material must have (1) a positive triboelectric relationship with respect to the silica and (2) the silica coated toner must be repelled from negatively charged areas of an imaging surface. The only positively stated purpose or utility for the silica is to reduce tackiness and improve the free flowing characteristics of the developer powder.
In copending U.S. Ser. No. 718,004, filed on Apr. 1, 1968 in the name of Frank M. Palermiti, now abandoned, it is taught that the inclusion at a minor proportion of hydrophobic metal salt of a fatty acid in an electrostatic developer overcomes certain problems associated with the use of prior art toner and carrier materials. Among the problems are the tendency of the toner to form unwanted deposits which interfere with copy quality and the long term abrasive affects of carriers and some toners. The metal salt of a fatty acid overcomes these problems, however, it has been observed that excessive buildup of the metal salt can likewise cause degradation of copy quality.
In U.S. Pat. No. 3,552,850 issued to Stephen F. Royka et al., it is taught to employ a dry lubricant when employing a blade cleaner in an electrostatographic imaging system. This patent, however, does not teach how to control the deleterious buildup of dry lubricant.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following examples further define, describe and compare exemplary methods of preparing the development system components of the present invention and of utilizing them in a development and cleaning process. Parts and percentages are by weight unless otherwise indicated. The examples, other than the control examples, are also intended to illustrate the various preferred embodiments of the present invention.
EXAMPLE I
The vitreous selenium drum of an automatic copying machine is corona charged to a positive voltage of about 800 volts and exposed to a light and shadow image to form an electrostatic latent image. The selenium drum is then rotated through a magnetic brush development station. A control developer comprising 2 parts of toner, containing a polystyrene resin and about 100 parts of steel shot carrier beads. The toner particles have an average particle size of about 12 microns and the carrier beads an average particle size of about 125 microns. After the electrostatic latent image is developed in the developing station, the resulting toner image is transferred to a sheet of paper at a transfer station. The residual toner particles remaining on the selenium drum after passage through the transfer station is removed by three different techniques. In each case, and in subsequent examples, it is to be understood that a clean selenium drum is employed in the examples.
One technique employs a cylindrical brush having an overall diameter of about 4 inches, a 15 denier polypropylene having a pile height of about 3/8 inch, and a fiber density of about 54,000 fibers per square inch. The brush is positioned against the drum to permit a fiber interference of about 0.1 inch and is rotated at about 175 revolutions per minute. Initial copy quality is excellent, however, after 25,000 copies, background density is very high, resolution is markedly decreased, image fill in solid and line copy is poor and edge definition is poor. Inspection of the drum reveals slight signs of wear and a significant buildup of toner on the surface thereof.
A second technique employs a cleaning web of the type disclosed by W. P. Graff, Jr. et al. in U.S. Pat. No. 3,186,838. A nonwoven rayon web contact pressure of about 18 pounds per square inch, web-photoreceptor relative speed of about 1.5 inches per second, and a web contact arc distance of about 1/8 inch are employed. After the copying process is repeated 5000 times, the copies show fairly good line contrast and little background deposit. However, large solid areas possess a washed out appearance. Micrograph studies of the drum surface reveal a significant buildup of toner film.
A third technique employs a doctor blade cleaning mode of removing residual toner. A rectangular 1/16 inch thick strip of polyurethane rubber-like material, having one end chamfered to form a cleaning edge having an angle of about 60°, is positioned parallel to the axis of the drum. The chamfered edge of the blade is held at a chiseling rather than wiping attitude with respect to the moving drum. The vertical resultant force employed to press the entire blade edge against the drum surface is about three pounds as read on a spring scale. Initial copies reveal good copy quality in all respects, however, after about 2000 copies, image quality is markedly inferior showing high background density, poor image fill and decreased resolution. Inspection of the drum reveals a significant buildup of toner on the imaging surface.
The foregoing illustrates the problem encountered when employing a typical toner material which of its very nature has a tendency to build up on the photoreceptor. The increasing buildup is undoubtedly the main cause of decline in copy quality.
EXAMPLE II
The developer procedure of Example I is repeated except that the developer is modified in the following manner: about 0.1 part of zinc stearate having a particle size distribution of from 0.75-40 microns is gently folded into one part of toner. The resulting mixture is thoroughly milled in a Szegvari attritor for about 10 minutes. After developed image transfer, as in Example I, the doctor blade and technique of Example I is employed except the blade force used is 0.2 pounds. After about 2000 cycles, the copies are characterized by high density and high background deposits. The surface of the selenium drum will be observed to have an excessive film buildup. The film deposit is either zinc stearate or a combination of the same with toner.
By increasing the blade force on the photoreceptor drum to about three pounds copy quality remained good through 2000 cycles.
The foregoing example illustrates that by employing a representative friction-reducing material, i.e., zinc stearate, in the developer composition, coupled with a cleaning means supplying sufficient force during cleaning, deleterious film buildup is effectively controlled.
The following examples illustrate that by employing a comparatively abrasive material in conjunction with the film forming lubricant, copies of exceptionally high quality are obtained by an even more effective control of film buildup.
EXAMPLE III
The developing procedure of Example I is repeated except that the developer is modified in the following manner: To the toner of Example I, 0.25% of zinc stearate is added and milled in a Szegvari attritor for ten minutes. Thereafter, 1.0% by weight of a treated submicron silicon dioxide is added and milled for an additional ten minutes. The treated silicon dioxide particles are produced by flame hydrolysis decomposition of pure silicon tetrachloride in the gaseous phase in an oxyhydrogen flame at about 1100°C followed by reaction in a heated fluidized bed reactor with dimethyl dichlorosilane. About 75% of the silanol groups present on the surface of the freshly prepared silicon dioxide particles are reacted with the silane in the fluidized bed reactor. The silicon dioxide particles have about 3 silanol groups per 100 A 2 of a surface prior to reaction with silane. Analysis of the final product reveals 99.8% SiO 2 and the balance carbon, Cl, heavy metals, Fe 2 O 3 , Al 2 O 3 , TiO 2 and Na 2 O 3 . The particle size is between about 10-30 millimicrons and the surface area is about 90-150 m 2 /g.
The relative coefficient of friction values for the several materials, determined by the technique described above, are as follows: Selenium 5.23, toner 3.92 and zinc stearate 0.67. The toner has a Shore Durometer hardness of greater than 100 on the A and B scale, zinc stearate 66 on the A scale and 52 on the B scale. The treated silicon dioxide has a hardness of about 5 on Moh's scale. After developed image transfer as in Example I, the blade cleaning technique of Example I is employed utilizing a blade force of about 3 pounds. After 2000 cycles, the copies are characterized by the same exceptionally high image quality as the initial copies. Inspection of the selenium drum will reveal a film buildup of less than 300 A.
EXAMPLE IV
The process of Example III is repeated except the dual additive consists of 0.25% of 10-20 micron cadmium stearate and 1.0% of 200 millimicron Kaophile 2, a commercially available hydrophobic aluminum silicate. The coefficient of friction of the cadmium stearate is 0.25 and the Shore Durometer hardness is 78 on the A scale and 66 on the B scale. After 2000 cycles, this developer yields copies of exceptional quality in every respect. The film buildup on the photoreceptor does not exceed 500 A.
EXAMPLE V
The process of Example III is repeated except the dual additive consists of 0.25% of 2-140 micron glycerol monostearate and 1.0% of the treated SiO 2 of Example III. The coefficient of friction of the glycerol monostearate is 1.57 and the Shore Durometer hardness is A scale 67, B scale 31. After 2000 cycles, this developer yields copies of outstanding quality in every respect. The film buildup on the photoreceptor does not exceed 300 A.
EXAMPLE VI
The process of Example III is repeated except the dual additive consists of 4.0% Carbowax 4000, a commercially available polyethylene glycol having a molecular weight of about 4000 and a particle size of 2-14 microns, and 6.0% Aerosil R972. The Aerosil R972 is a commercially available material substantially identical to the treated silica of Example III. The coefficient of friction of the Carbowax is 4000 is 1.63 and the Shore Durometer hardness is A scale 95. The residual developer material remaining on the selenium drum after passage through the transfer station is removed by a rotating cylindrical brush and vacuum system. After 2000 cycles, this developer yields copies of excellent quality. The film buildup on the photoreceptor is not in excess of 700 A.
EXAMPLE VII
The process of Example III is repeated except the dual additive consists of 0.25% cholesterol and 1.0% Aerosil R972. The cholesterol has a particle size range of 5-140 microns, a coefficient of friction of 2.1 and a Shore Durometer hardness of B scale 72. After 2000 cycles, copies of excellent quality were realized. The film buildup on the photoreceptor is not in excess of 300 A.
EXAMPLE VIII
The process of Example III is repeated except the dual additive is 0.25% PCL-150, which is a commercially available polycaprolactone having a molecular weight of about 4000, and 1.0% Aerosil R972. The PCL-150 has a particle size range of 2-140 microns, a coefficient of friction of 2.0 and a Shore Durometer hardness of A scale 95. After 2000 cycles this developer yields copies of outstanding quality in every respect. The film buildup on the photoconductor is not in excess of 300 A.
EXAMPLE IX
The process of Example III is repeated except the dual additive is 0.25% Vydax, a low molecular weight, waxy, smearable telomer of tetrafluoroethylene available from E. I. DuPont, Wilmington, Delaware, and 1.0% Aerosil R972. Vydax has a particle size range of from 2-100 microns, a coefficient of friction of less than that of the toner material, a Shore Durometer hardness of 72 on the B scale and a melting point of 300°C. After 2000 cycles, this developer yields copies of a quality comparable to that of Examples III-VIII. Residual film buildup will not exceed 300 A.
EXAMPLE X
The process of Example III is repeated except the dual additive consisted of 0.25% terephthalic acid and 1.0% Aerosil R972. The terephthalic acid has a coefficient of friction of 0.40 and a Shore Durometer hardness of 96 on the B scale. This developer, after 2000 cycles, likewise yields copies of a quality comparable to that of Examples III-VIII. Residual film buildup will not exceed 400 A.
EXAMPLE XI
The process of Example III is repeated except the dual additive consists of 0.25% perchloropentacyclodecane and 1.0% titanium dioxide. The perchloropentacyclodecane has a coefficient of friction of 1.0 and a Shore Durometer hardness of 87 on the B scale. The titanium dioxide has an average particle size of about 30 millimicrons. This developer, after 2000 cycles, yields copies of a quality comparable to that of Examples III-VIII. The residual film buildup will not exceed 300 A.
EXAMPLE XII
The process of Example III is repeated except the dual additive consists of 0.25% stearyl alcohol and 1.0% antimony trioxide. The stearyl alcohol has a coefficient of friction less than that of the toner and a Shore Durometer hardness of less than that of the toner. The antimony trioxide powder has an average particle size of 100 millimicrons. This developer, after 2000 cycles, yields copies of a quality comparable to that of Examples III-VIII. The residual film buildup will not exceed 400 A.
EXAMPLE XIII
The process of Example III is repeated except the dual additive consists of 0.25% zinc stearate and 1.0% untreated submicron silicon dioxide. The silicon dioxide is identical to that of Example III except it is not treated to render it organophilic. The process is operated at a relative humidity of about 80% at an average temperature of about 75°F. The background density, resolution, image fill in line copies and edge definition are good in initial copies. However, after about 900 copies, background density has more than doubled, resolution has decreased, image-fill in line copies is poor and edge-definition is poor. The photoreceptor reveals a dull damp claylike film which cannot be removed by ordinary cleaning techniques.
The same process carried out at a relative humidity of 30% at about 75°F yields excellent copies after about 2000 cycles. No claylike film is observed on the photoreceptor surface.
When the treated silicon dioxide of Example III is employed in the composition under the high relative humidity condition of about 80% at 75°F image quality remains excellent and no colloidal silica deposit is observed on the photoreceptor.
It is believed that the voluminous, high surface area, untreated silica acts as desiccant and the water taken up by the additive deleteriously affects all aspects of the development and cleaning steps of the process. Under comparatively dry conditions this is not observed.
EXAMPLE XIV
The process of Example II is repeated except a reversal development mode is employed. About 100 parts of 250 micron steel shot, the particles of which are coated with a mixture of a copolymer of polyvinylchloride and polyvinylacetate with Luxol Fast Blue, a commercially available dye, is mixed with 1 part of a toner consisting of 65% polystyrene, 35% poly-n-butylmethacrylate and 10% carbon black. This reversal developer also contains 1.0% by weight of Al 2 O 3 based on the weight of toner. The Al 2 O 3 has an average particle size of 30 millimicrons. Effective development is achieved in the discharged areas of the imaging surface. After 1000 cycles, the copies are excellent in every respect. Residual developer buildup on the imaging surface will not exceed 300 A.
EXAMPLE XV
The developing procedure of Example III is repeated except instead of zinc stearate, 0.25% of copper stearate is employed. The coefficient of friction of the copper stearate is less than that of the toner and its Shore Durometer hardness is less than that of the toner. After 2000 cycles, this developer yields copies of good quality in every respect. The film buildup on the photoreceptor does not exceed 300 A.
Although specific materials and conditions are set forth in the foregoing examples, these are merely intended as illustrations of the present invention. Various other suitable toner components, additives, colorants, carriers and development techniques such as those listed above may be substituted for those in the examples with similar results. Other materials may also be added to the toner or carrier to sensitize, synergize or otherwise improve the imaging properties or other desirable properties of the system.
Other modifications of the present invention will occur to those skilled in the art upon a reading of the present invention. These are intended to be included within the scope of this invention. | A developer composition comprising (1) electroscopic toner particles (2) a friction-reducing material of a hardness less than said toner and having greater fricton-reducing characteristics than said toner material, and (3) a finely divided nonsmearable abrasive material of a hardness greater than said friction-reducing and toner materials. An imaging and development process utilizing the above-identified composition including the step of maintaining the buildup of friction-reducing material on an imaging surface in the submicron range without completely removing or preventing said buildup, by the combined action of a cleaning force wiping at least any residual developed image from at least a portion of said imaging surface. | 6 |
FIELD OF THE INVENTION
[0001] This invention relates to regenerable antimicrobial animal fiber materials and methods for preparing the same and in particular to the animal fiber materials to which a heterocyclic N-halamine is covalently attached.
BACKGROUND OF THE INVENTION
[0002] Animal fiber materials such as leather, fur skin, wool, silk, have been manufactured to clothes, comforts, and furniture for a long time. Various synthetic fibers have bees developed by modem technology to substitute various natural fibers, but the synthetic fibers can not completely replace natural fiber materials, especially animal fibers. Because animal fiber has good quality, special functions and pretty appearance and is always a symbol of high class clothes, furniture, car seats, etc. Animal fiber has many advantages, but has one serious drawback. That is, it causes growth of bacteria, mold, and virus, etc. Therefore, the surface of animal fiber has molds, corrosion, even odor leading to poor material quality, poor material durability. Therefore, there is a need in the art to invent methods to prepare antimicrobial animal fiber materials having biocidal activity against pathogenic microorganisms such as bacteria, fungi, virus, etc. and the materials still have good quality and durability.
SUMMARY OF THE INVENTION
[0003] The object of the present invention is to provide regenerable antimicrobial animal fiber materials which are prepared in a aqueous finishing process to covalently attach a heterocyclic N-halamine to a animal fiber based material. The finished antimicrobial animal fiber materials used for a period of time can be washed with a chlorine containing solution such as a bleach solution containing active chlorine. Such treated animal fiber materials can recover antimicrobial activity. Therefore, the present invention provides regenerable antimicrobial animal fiber materials.
[0004] The further object of the present invention is to provide a method for preparing regenerable antimicrobial animal fiber materials by adding a heterocyclic N-halamine in an aqueous finishing process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] [0005]FIG. 1 shows the molecular structures of the embodiments of heterocyclic N-halamine used in this invention.
[0006] [0006]FIG. 2 shows the flow chart of preparing antimicrobial leather product from flesh hide and skin such as cattle hide, sheep hide, pig hide, fur skin in accordance with the protocol set forth in Example 1 of this invention.
[0007] [0007]FIG. 3 shows the flow chart of preparing regenerable antimicrobial wool, silk in accordance with the protocol set forth in Example 2 of this invention
[0008] [0008]FIG. 4 shows the flow chart of preparing regenerable antimicrobial duck down, goose down in accordance with the protocol set forth in Example 3 of this invention.
[0009] [0009]FIG. 5 shows the quantitative antibacterial study of regenerable antimicrobial leather finished by solution containing different weight percent of NT-I in accordance with protocol set forth in Example 1.
[0010] [0010]FIG. 6 shows the quantitative antibacterial study of antimicrobial cloth of wool, silk finished by solution containing different weight percent of NT-II in accordance with protocol set forth in Example 2.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0011] The present invention provides a method for preparing regenerable antimicrobial animal fiber materials. Such materials are prepared in a conventional processing of animal fiber materials comprising acetalization after which a heterocyclic N-halamine is added in an aqueous finishing process. The animal fiber materials comprise flesh hide and skin, wool cloth, silk cloth, duck down, goose down, etc. The prepared regenerable antimicrobial animal fiber materials according to the present invention comprise leather, wool cloth, silk cloth, duck down, goose down, etc.
[0012] Heterocyclic N-halarnine, as used in this invention, refers to a 4 to 7-membered ring, wherein at least 3 members of the ring are carbon, and from 1 to 3 members of the ring are nitrogen heteroatom, and from 0 to 1 member of the ring is oxygen heteroatom, wherein from 0 to 2 carbon members comprise a carbonyl group, and wherein at least 1 to 3 nitrogen atoms are substituted with a hydrogen or hydroxyalkyl group, such as —CH 2 OH, or a alkoxyalkyl group, such as —CH 2 OCH 3 . At least one ring nitrogen has bonded thereto a halogen atom. In addition, the ring members can be further substituted with alkyl groups, such as methyl, ethyl, etc., or hydroxy groups.
[0013] [0013]FIG. 1 shows the molecular structures of the two heterocyclic N-halamine compounds used in this invention. One compound is monomethylol-5,5-dimethylhydantoin (MDMH), referred as NT-I hereinafter. The other compound is 1,3-dimethylol-5,5-dimethylhydantoin (DMDMH), referred as NT-II hereinafter.
[0014] The method to prepare regenerable antimicrobial animal fiber materials from animal fiber based materials of this invention is as follows:
[0015] a. Carry out hydrolysis for animal fiber materials;
[0016] b. Proceed with acetalization in the aqueous solution;
[0017] c. Add heterocyclic N-halamine such as NT-I or NT-II to the acetalized solution to form NT-I or NT-II bonded fiber molecule; and
[0018] d. Carry out chlorination for the precursor of the finished antimicrobial animal fiber material, the NT-I or NT-II bonded fiber molecule formed in step c.
[0019] The present invention will be better understood from the following Examples which are merely for the purpose of illustration and by no means of any limitation therefore.
EXAMPLE 1
[0020] This example illustrates the finishing of animal fiber material with NT-I. The flow chart for the method to prepare antimicrobial leather such as cattle leather, sheep leather, pig leather from flesh hide and skin is shown in FIG. 2. First carry out tanning of flesh hide and skin, mechanical cutting, and dying thereof in tanks A, B, C respectively in accordance with FIG. 1. The detailed processing of the rest steps are as follows.
[0021] a. Acidification and hydrolysis:
[0022] Add 6000 g of sodium sulfate (acid agent), 100 L of water, ethylacetate catalyst 750 g to the tanks. The catalyst is 1.5% wt based on the total weight of the dyed flesh hide and skin, 50 kg;
[0023] b. Acetalization:
[0024] Add 600 g of aldehyde and 15000 g of sodium sulfate to the tanks;
[0025] c. Addition of NT-I:
[0026] 3000 g, 4000 g, and 5000 g of NT-I are added to tanks A,B, and C respectively. The weight percentages of NT-I in tanks A,B, and C are 6% wt, 8% wt, and 10% wt respectively based on the total weight of the dyed flesh hide and skin, 50 kg. Tanks A, B, and C are agitated mechanically at room temperatures. Next, stop agitation for a period of time.
[0027] Then proceed with drying, chlorination, drying, coating in each tanks, and antimicrobial leather is obtained as shown by FIG. 2. The chlorination is carried out by washing with a bleach solution containing 0.1% chlorine for a couple of minutes. The NT-I added refers to monomethylol-5,5-dimethylhydantoin. The purpose of using sodium sulfate in acetalization step is to reduce the formation of hydrogen bonds between neighboring hydroxy group in fiber molecule so as to avoid formation of crystalline arrangements. Antibacterial properties of the finished animal fiber material, leather, is tested against bacteria such as E. coli., Staphylococcus aureus ( S. aureus ), and Pneumobacillus using the protocol set forth in Example 4.
EXAMPLE 2
[0028] This example illustrates the finishing of animal fiber material with NT-II. The flow chart for the method to prepare antimicrobial cloth of wool, silk from dyed cloth of wool, silk is shown in FIG. 3. The detailed steps of this process are as follows:
[0029] 1. Dyed cloth of wool, silk:
[0030] The starting material is dyed cloth of wool, silk;
[0031] 2. Drying:
[0032] Dry the cloth by squeezing water out and heating the cloth;
[0033] 3. Addition of NT-II:
[0034] Add NT-II solution to a tank so that the weight percentages of NT-II in the tank can be 6% wt, 8% wt, or 10% wt based on the total weight of the dyed cloth prepared in step 2. Agitate the solution mechanically for a period of time at room temperatures;
[0035] 4. Immerse cloth:
[0036] Load the dyed cloth in the tank containing the NT-II solution;
[0037] 5. Forming by roller squeeze:
[0038] Take out the dyed cloth from the tank and dry and form the dyed cloth by roller squeeze;
[0039] 6. Chlorination:
[0040] The dyed cloth is washed by a bleach solution containing 0.1% chlorine for a couple of minutes;
[0041] 7. Drying:
[0042] Dry the dyed cloth by squeezing water out and heating the cloth;
[0043] 8. Antimicrobial cloth of wool, silk is obtained.
[0044] Wherein NT-II refers to 1,3-dimethylol-5,5-dimethylhydantoin. Antibacterial properties of the NT-IL finished cloth are tested against bacteria such as Bacillus subtilin ( B. subtilin ), Staphylococcus aureus ( S. aureus ), E. coli using the protocol set forth in Example 5.
EXAMPLE 3
[0045] This example illustrates the finishing of animal fiber material with NT-II. The flow chart for the method to prepare antimicrobial duck down, goose down is shown in FIG. 4. The detailed steps of this process are as follows:
[0046] 1. Duck down, goose down:
[0047] The starting material is duck down, goose down;
[0048] 2. Drying:
[0049] Dry the down by squeezing water out and heating the down;
[0050] 3. Addition of NT-II:
[0051] Add NT-II solution to a tank so that the weight percentages of NT-II in the tank can be 6% wt, 8% wt, or 10% wt based on the total weight of the duck down, goose down prepared in step 2. Agitate the solution mechanically for a period of time at room temperatures;
[0052] 4. Immerse down:
[0053] Load the down in the tank containing the NT-II solution;
[0054] 5. Forming by roller squeeze:
[0055] Take out the down from the tank and dry and form the down by roller squeeze;
[0056] 6. Chlorination:
[0057] The down is washed by a bleach solution containing 0.1% chlorine for a couple of minutes;
[0058] 7. Drying:
[0059] Dry the down by squeezing water out and heating the down;
[0060] 8. Antimicrobial duck down, goose down is obtained.
[0061] Wherein NT-II refers to 1,3-dimethylol-5,5-dimethylhydantoin.
EXAMPLE 4
[0062] This example illustrates the quantitative antibacterial study (AATCC Test Method 100) of NT-I finished leather prepared from solutions containing 6-10% wt of monomethylol-5,5-dimethylhydantoin following the protocol set forth in Example 1. The antibacterial properties of such leather materials are set forth in FIG. 5. FIG. 5 shows that at a very low concentration of NT-I, antibacterial properties can be obtained for the finished leather.
[0063] AATCC Test Method 100 is adopted in this study. According to this test method, four pieces of staked circular animal fiber swatches 4.8±0.1 (about 1 grams) are inoculated with 1.0±0.1 milliliter of inoculum in a 250 milliliter jar. The inoculum is a nutrient broth culture containing more than 1,000,000 clone forming units (CFU) of organisms. After the swatches are inoculated, they are neutralized by 100 ml of a 0.02% sodium thiosulfate solution in the jar. The contact time is the time between the inoculation and neutralization. The jar is shaken vigorously and the neutralized solution is diluted in serial. The dilutions, usually 1, 10, and 100, are plated on nutrient agar and incubated for 18-24 hours at 37° C. The number of bacteria recovered from the inoculated finished leather is counted and compared with that from untreated flesh hide and skin. Six log reduction means the total inactivation of bacteria, and one log reduction means that the finished leather reduced bacteria counts from 1,000,000 to 100,000 CFU.
EXAMPLE 5
[0064] This example illustrates the quantitative antibacterial study (AATCC Test Method 100) of NT-II finished cloth of wool, silk prepared from solutions containing 6-10% wt of 1,3-dimethylol-5,5-dimethylhydantoin following the protocol set forth in Example 2. The antibacterial properties of such cloth are set forth in FIG. 6. FIG. 6 shows that at a very low concentration of NT-II, antibacterial properties can be obtained for the finished cloth of wool, silk.
[0065] AATCC Test Method 100 is adopted in this study. According to this test method, four pieces of staked circular animal fiber swatches 4.8±0.1 (about 1 grams) are inoculated with 1.0±0.1 milliliter of inoculum in a 250 milliliter jar. The inoculum is a nutrient broth culture containing more than 1,000,000 clone forming units (CFU) of organisms. After the swatches are inoculated, they are neutralized by 100 ml of a 0.02% sodium thiosulfate solution in the jar. The contact time is the time between the inoculation and neutralization. The jar is shaken vigorously and the neutralized solution is diluted in serial. The dilutions, usually 1, 10, and 100, are plated on nutrient agar and incubated for 18-24 hours at 37° C. The number of bacteria recovered from the inoculated finished cloth of wool, silk is counted and compared with that from untreated cloth of wool, silk. Six log reduction means the total inactivation of bacteria, and one log reduction means that the finished leather reduced bacteria counts from 1,000,000 to 100,000 CFU.
[0066] The finished antimicrobial animal fiber materials of this invention used for a period of time can be washed by a dilute chlorine containing solution such as a chlorine bleach solution and then dried. Such treated animal fiber material can recover theirs antimicrobial activity. Therefore, the present invention provides regenerable antimicrobial animal fiber materials.
[0067] Although preferred embodiments have been described to illustrate the present invention, it is apparent that changes and modifications in the described embodiments can be carried out without departing from the scope of the invention intended to be limited only by the appended claims. | This present invention provides regenerable antimicrobial animal fiber materials and methods for preparing the same. Such animal fiber materials are prepared using an aqueous finishing process to covalently attach a heterocyclic N-halamine to an animal fiber material. Once prepared, the finished animal fiber materials of the present invention have antibacterial activity against pathogenic microorganisms. Moreover, the antibacterial activity of such animal fiber materials can be regenerated by washing with a chlorine containing solution. | 3 |
CROSS SECTION TO RELATED APPLICATIONS
[0001] The present application claims priority to European Patent Application 03010942.5, filed May 15,2003, which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a method for displaying a graphic containing contours on a display unit.
[0003] The present invention relates to the area of portable information and communication technology devices. Dictated by the relatively small size and the associated low pixel and color resolution of a display unit on a portable device graphic displays such as conventional images or special graphics must be edited for display. This editing is also necessary for the reduced display of large maps on high-resolution screens or a display with few colors for the purposes of image compression.
[0004] In Document WO 00/46748 A1 a method for creating a color descriptor of an image is published: This method includes the following steps:
[0005] a) Determining the color vectors of a specified image;
[0006] b) Classification of the color vectors in order to determine the dominant color and the interrelationships;
[0007] c) Display of the dominant color's and their relationships to each other as a color descriptor of the specified image.
[0008] The color descriptor of an image mentioned above includes typical characteristics of an image. The method in accordance with the document WO 00/46748 A1 is used in object-based image processing systems to allow a simpler search and faster location of a specific content or pattern.
[0009] As in the document mentioned above the images or graphics are mostly present in an n·m pixel format. Each pixel in this case is assigned a specific position within a grid and a specific color. Graphics such as topographical or geographical maps are mostly originally present in a vector representation. Such maps will however be previously converted into a pixel format of the type mentioned above for publication or for output at a display unit.
[0010] Editing the display requires a reduction in the number of pixels. This is normally done by a selection method, referred to technically as <<subsampling>>. In this case methods are used such as formation of averages or a subsampling of a specific pixel from a matrix of for example 4×4 pixels. For example the pixel located in the top left corner of this 4×4-matrix can be used here. These procedures are entirely suitable for images which do not feature any specific contours. The term <<specific contours>>includes the fact that these contours are assigned a defined semantic such as for example in the area of topography in accordance with the representation shown below in Table 1.
TABLE 1 Semantic of the colors with regard to the contours Contour Semantic Blue line River, stream Blue line which delimits a Shore of a lake light blue surface. Thin black line Co-ordinate grid Thin brown Line Height contour Green line which delimits a Woodland edge light green surface.
[0011] The disadvantage of the above-mentioned methods of displaying such graphics is that, because of the absence of these contours the readability is significantly adversely affected. The term contour used above and its significance is in no way restricted here to cartography but can for example also be applied to other graphics such as for example a graph curve or a temperature curve within a Cartesian co-ordinate system.
[0012] The negative effects in the presentation of a graphic in a pixel display such as for example anti-aliasing can also be rectified by what is known as <<super sampling>>. <<Super sampling>>means that the pixels are initially edited in a memory. In this case this memory is virtually assigned a higher resolution than the actual resolution on the display unit. The disadvantage of this method (also called: <<super sampling method of anti-aliasing>>) is the high memory requirement and the associated high computing power. To ameliorate the problem of a high memory requirement somewhat it is proposed in EP 1 056 047 A1 to remedy this by a weighted decomposition into three basic colors and a subsequent linear combination of the colors for each pixel. However this does not display colors with a specific significance any better since even at the high resolution the individual elements are present as <<areas>>and not as contours.
[0013] The method described in WO 00/46748 A1 is therefore not suitable for contour-containing reduction of an image because it is to be applied above all to a large monochrome regions: Fine contours especially get lost in filtering as noisy pixels>>, see WO 00/46748 A1, Page 4 for more information.
SUMMARY OF THE INVENTION
[0014] An object of the present invention is thus to specify an easy-to-implement method for displaying a graphic containing contours on a display unit, in which the contours are even retained for a reduction to a display with lower resolution.
[0015] This and other objects are achieved in accordance with the invention by the method specified in Patent claim 1 .
[0016] By the steps i) to v) of the method in accordance with invention, whereby through
[0017] i) Assignment of a weighting of the colors representing the contours and the surfaces is undertaken, with the weighting being undertaken by a factor f c determined by the colors C;
[0018] ii) decomposition of the graphic G into blocks B ij , which each feature a·b pixels; with a standing for number of pixels of a row and b for the number of pixels of a column of a block B ij ,
[0019] iii) Determining the dominant color C of each block B ij on the basis of the weighting undertaken in procedural step A;
[0020] iv) Mapping of the dominant color C of each Block B ij to a pixel, in which case the dominant color C is created from basic colors.
[0021] v) Recomposition of the graphic G from the pixels determined in procedural step C.
[0022] It is ensured that the contours contained in the graphic G are retained on reduction to a lower resolution.
[0023] The weighting of the colors C representing the contours can be undertaken previously in procedural step i) depending on the relevant application such as a diagram with a pillar or line design or a map. This allows the subsequent procedural steps to be applied in many diverse ways independent of the specific semantic inherent to the contours of the graphic.
[0024] The invention is not restricted to portable devices but can be used wherever a graphic containing contours is to be shown on a relatively small display such us for example a navigation system in a means of transport, typically an automobile.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0025] The invention is explained below in more detail on the basis of the drawing. The drawing shows:
[0026] [0026]FIG. 1 Flowchart for processing a block section.
DETAILED DESCRIPTION OF THE INVENTION
[0027] It is assumed that the graphic to be a displayed his present in a pixel display of n·m pixels; in this case a color C is assigned to each pixel. Initially a plurality of blocks B ij is created from the graphic G to be shown on a display unit, with the indices running in each case over i ∈ {1, . . , M} and j ∈ {1, . . , N}. The graphic G thus produces the equation:
:=[ B ij ]mit i ∈{1 , . . , M}; j ∈{1 , . . , N}.
[0028] A block B ij contains on one hand a·b pixels, preferably a=b, applies here, which means that the blocks B ij are quadratic. Typical values for a and b are 1, 2, 4 or 8. For the above variables the following relationship applies for an exact decomposition
n=N·a;
m=M·b.
[0029] N, M contain—as formally specified above—the number of blocks per row or per column respectively of graphic G.
[0030] If an exact decomposition of this type is not possible then for the example a few pixels at the edge of the rectangular graphic G are ignored. Since for the variables n and m values of between typically 600 and 1800 are provided, a very small loss is produced with the specified values for a and b as regards the display of the graphic G on a display unit. The above-mentioned values only represent examples, for large TFT flat screens larger values are also to be provided.
[0031] Each block formed in its way B ij ∈ G when will be subjected to the procedural steps in accordance with FIG. 1 as shown below.
[0032] Block 20
[0033] Selection of a block B ij ∈ G.
[0034] Branch 201
[0035] Query: Reduction of the number of pixels. This branch its optional for the No case (reference symbol N) and merely represents a back up so that a graphic reduced or made smaller in accordance with the inventive method is not subjected to this method for the second time. In the Yes case (reference symbol Y) the number of pixels is reduced in accordance with the operations specified in the following blocks 21 , 22 .
[0036] In block 21 different colors C of the underlying block B are counted.
[0037] Subsequently in block 22 the dominant color is determined. This is done by weighting the colors counted in block 21 . So called surface colors such as for example a light green (wooded area) or light blue (sea surface) have the lowest weight. Contours or the assigned colors such as black or dark blue have the highest weight. This method ensures that the contours are not lost on averaging or reduction to fewer pixels. Without this weighting for example a coordinate line within a light green area but representing a wood would at least partly disappear. For the weighting of the colors C the factors f c listed in Table 2 will be included. In this table a distinction is made between basic colors C and so-called pseudo colors C. These factors f C are to be specified for a specific map in what is known as “hard coded” form. Depending on the type of map or the national circumstances the basic colors have another meaning. The weighting and the establishment of the table are therefore undertaken in advance for a specific application and not just at “runtime” of the procedure.
TABLE 2 Weighting by factors f c of the basic and pseudo colors as a result of their meaning/semantics. Factor f c Meaning Basic color C White −2 Background Green 1 Woodland edge Blue 0 Rivers, streams Brown 2 Height line Black 2 Roads Pseudo color C Light green −2 Woodland area Light blue −2 Sea surface Yellow 0 Narrow road Orange 0 National class 1 highway Red-orange 0 National border Red 0 Major road Dark red 0 Railway line
[0038] For determining the weighted average the procedures in this exemplary embodiment are as follows:
[0039] The weight g C of a color C is calculated using the following formula:
g
C
:=h
C
+f
C
·f
s
1
[0040] where
[0041] h C Number of pixels with the color C;
[0042] f C Factor of the color C;
[0043] f s quadrated scaling factor F s /4.
[0044] The quadrated scaling factor F s is produced by the pixel format to be reduced, in the present example from
F s =4·4=16.
[0045] The formula given here F 1 for calculating the weight g C of a color C is explained on the basis of an example for a block B ij of 4·4 pixels in Table 3:
TABLE 3 Calculating the weight g c of a color C. Number h c of Formula the pixels with with Weight g c of Color C the color C numbers the color C Black 5 5 + 2 * 4 13 Light green 9 9 − 1 * 4 5 Green 2 2 + 1 * 4 6 16
[0046] This means that determining the dominant color produces the color black. It should be pointed out at this juncture that the formula given here F 1 for the weight g C , represents an example of weighting. It would also be possible to perform the weighting purely multiplicatively and not mixed as in the formula given here.
[0047] For the branch 202 following block 22 it is possible to make this branch solely on the basis of the decision for the dominant color or the found weights g C . for the different colors en bloc.
[0048] There now follows the further branch 202 already mentioned. Here, if the number of pixels of the dominant color black is less than the total number of pixels in a block B ij , a color representation is generated according to the following table. To simplify the representation in this case only a size of 2·2 pixels is assumed for a block B ij here.
TABLE 4 Creation of anti-aliasing colors Number of pixels of the Mapping to a dominant color black pixel of the color 4 Black 3 Black 2 Brown 1 Brown
[0049] In the case of 4 pixels the color black is assigned directly to the pixel concerned.
[0050] In block 23 (=anti-aliasing with weighting) it is established which of the basic colors available best represents the dominant color and the found weights. In this example this only applies for the color black with its anti-aliasing brown, since no anti-aliasing is available for the other colors. For these colors however the pseudo colors can be used as anti-aliasing.
[0051] Because of the previously determined colors per “reduced” block B ij the color is therefore determined in block 24 on the basis of the “basic colors” available for a display unit. In the case considered here this is the first five lines of Table 5.
TABLE 5 Creating pseudo colors from the basic colors. Color C Color White Green Blue Brown Black (input) (output) W G B N Z White W100 100% Green G100 100% Blue B100 100% Brown N100 100% Black 2100 100% Pseudo colors Light green W50G50 50% 50% Light blue W75B25 75% 25% Yellow W5ON25Z25 50% 25% 25% Orange W50N50 50% 50% Red-orange G25N75 25% 75% Red N10D 100% Dark red N50Z50 50% 50%
[0052] The second column of Table 5 specifies the output in a coded form for a specific color in the first column. The columns with the headings “White W”, “Green G”, etc. specify the encoding/weighting on the basis of the available basic colors C. Instead of the term encoding/weighting this generation of pseudo colors is also referred to a specified linear combination of basic colors.
Example 1
[0053] Creation of W50N25Z25 by means of color dithering in a 2·2 dithering block the colors are arranged as follows:
TABLE 6 2 · 2 Dithering-Block D W50N25Z25 (i, j) White Brown Black White
Example 2
[0054] Creation of W66B34 by means of color dithering
[0055] In a 3·3 dithering block the colors are arranged as follows:
TABLE 7 3 · 3 dithering block D W66B34 (i, j) Blue White White White White Blue White Blue White
[0056] The following comment should also be made here: Blocks B ij with identical colors but different positions (i,j) create another color with color dithering. For example when the. dithering block W66B34 is used the color DW 66B34 (i mod 3 , j mod 3 ) is created.
[0057] If with branch 201 the decision is made not to perform any reduction, then in block 24 for the pixels concerned the color C is merely determined from the specified basic colors in accordance with Table 5.
[0058] Block 25 contains the resulting representation (output) for a pixel as a result of input 20 (=Input) for a block B ij ∈ G of the graphic to be displayed G.
[0059] The sequence in accordance with FIG. 1 represents an execution sequence for a block B ij or in the case of the non-reduction for a pixel. To display a graphic G the sequence shown in FIG. 1 is run iteratively. The steps of the decomposition into blocks B ij as well as the recomposition of the graphic G from the pixels created in this way represent an expert measure and are thus not explained in any greater detail in this publication. Likewise no further details are provided about the transformation of the graphic G in a vectorized form into the pixel form previously mentioned.
[0060] The exemplary embodiment given above merely represents an implementation of the method in accordance with the invention. Depending on the display options, the inventive method can be performed on a display unit with other colors C and with other numbers of basic colors. The weighting of the colors C is only conditionally linked to the relevant semantics and accordingly to a specific application. It is also possible to index the specified so-called “hard-coded” Tables, with each index standing for a specific application. In a similar way to that shown in Table 8 graphics G that differ very widely in type and semantic can be automatically reduced with the same method to cater for the options provided by a display unit so that the importance of the individual elements such as the contours of the relevant graphic G in particular are retained.
TABLE 8 Index for indexing Tables 1, 2 and 4. Index Application 0 Map representation in CH semantics. 1 Map representation in IT semantics. 2 Representation of temperature curves. 3 Representation of stock market indices. . . . . . .
[0061] The next few pages show the code of the exemplary embodiment for showing a geographical map in the C Language.
[0062] Code in programming language C of the sequence shown in FIG. 1
////////////////////////////////////////////////// //Weighted Anti-aliasing and Color Dithering code ////////////////////////////////////////////////// #define WHITE 0 #define BROWN 1 #define BLUE 2 #define BLACK 3 #define GREEN 4 #define DARK_GREEN 5 #define DARK_BLUE 6 #define RED 7 #define DARK_RED 8 #define YELLOW 9 #define GRAY 10 #define ORANGE 11 #define RED_ORANGE 12 //Dithered colors: //Light Green: Combinations of White and Green #define WHITE75_GREEN25 20 #define WHITE50_GREEN50 21 #define WHITE25_GREEN75 22 #define BLACK25_GREEN75 27 //Light Blue: Combinations of White and Blue #define WHITE75_BLUE25 30 #define WHITE50_BLUE50 31 #define WHITE25_BLUE75 32 #define BLACK25_BLUE75 37 //Light Black: Combinations of white and black #define WHITE75_BLACK25 40 #define WHITE50_BLACK50 41 #define WHITE25_BLACK75 42 //Light Brown: Combinations of White and browN #define WHITE75_BROWN25 50 #define WHITE50_BROWN50 51 #define WHITE25_BROWN75 52 #define WHITE62_BROWN38 53 #define WHITE67_BROWN33 54 #define WHITE50_BROWN25_BLACK25 55 #define BLACK50_BROWN50 58 //Combination of Green and browN: #define GREEN75_BROWN25 60 #define GREEN50_BROWN50 61 #define GREEN25_BROWN75 62 void Tile::Write_all( ) { Strip_index Strip = 0; // Before saving images apply Anti-Aliasing routine Anti_aliasing( ); while (Strip < Temp_Tile_Side) { write (Strip); Strip += Scale_Change; } Empty_all ( ); } void Tile::Anti_aliasing( ) { //Apply Anti-aliasing only if there is a scale change. //Otherwise do only color dithering; if (Scale_Change == 1) { Dither_tile( ); return; } const int Scale_square_2 = Scale_Change * Scale_Change / 2.0; const int Scale_square_4 = Scale_Change * Scale_Change / 4.0; int colors_num = 13; int colors[16]; int max, i; int dominant_color, color; int colors_add[16]; int PixelIndex; //Initialize counter of pixel colors: for (i = 0; i < colors_num; i++) { colors_add[i]=0; } // Emphasize BROWN and BLACK: colors_add[BROWN] = Scale_square_4; colors_add[BLACK] = Scale_square_4; // Little Emphasize for DARK_GREEN and DARK_BLUE: colors_add[DARK_GREEN] = Scale_square_4/2; colors_add[DARK_BLUE] = 0; // Penalty for surface colors: colors_add[WHITE] = −Scale_square_4; colors_add[GREEN] = −Scale_square_4; colors_add[BLUE] = −Scale_square_4; //Double loop over all tiles: for ( int y = 0, yEven = 1, yEven3 = 1; y < Temp_Tile_Side; y += Scale_Change, yEven = 1 − yEven) { if( ++yEven3 >= 4) {yEven3 = 0;} for ( int x = y * Temp_Tile_Side, xEven = 1, xEven3 = 1; x < (y+1) * Temp_Tile_Side; x += Scale_Change, xEven = 1 − xEven) { if( ++xEven3 >= 4) {xEven3 = 0;} // Count colors in pixel block for (i = 0; i < colors_num; i++) { colors[i] = 0; } for (int x0 = 0; x0 < Scale_Change; x0++){ for (int y0 = 0; y0 < Scale_Change; y0++){ colors[Tile_pixels[x + x0 + y0 * Temp_Tile_Side]]++; } } // Find color with maximum count: dominant_color = WHITE; max = 0; for (i = 0; i < colors_num; i++) { colors[i] += colors_add[i]; if(colors[i] >= max) { max = colors[i]; dominant_color = i; } } //Antialiasing of BLACK color: IF BLACK is not //omnipresent replace it by BROWN: if(dominant_color == BLACK) { if(colors[WHITE] >= Scale_square_4 && colors[WHITE] < Scale_square_2 && colors[BLACK] >= Scale_square_2) { dominant_color = BROWN; } } //Color dithering using the dithering pattern: dominant_color = Dither_color(dominant_color, xEven, yEven, xEven3, yEven3); // Set dominant_color in a pixel block // with side length Scale_change: for (int y0 = 0; y0 < Scale_Change; y0++){ PixelIndex = x + y0 * Temp_Tile_Side; for (int x0 = 0; x0 < Scale_Change; x0++, PixelIndex++){ Tile_pixels[PixelIndex] = dominant_color; } } } } } //Dithering without down scaling: void Tile::Dither_tile( ) { srand(1); int PixelIndex; for ( int y = 0, yEven = 1, yEven3 = 1; y < Temp_Tile_Side; y++, yEven = 1 − yEven) { if( ++yEven3 >= 4) {yEven3 = 0;} PixelIndex = y * Temp_Tile_Side; for ( int x = 0, xEven = 1, xEven3 = 1; x < Temp_Tile_Side; x++, PixelIndex++, xEven = 1 − xEven) { if( ++xEven3 >= 4) {xEven3 = 0;} Tile_pixels[PixelIndex] = Dither_color(Tile_pixels[PixelIndex], xEven, yEven, xEven3, yEven3); } } return; } //The toggle even allows to select the position in the dithering pattern; //Even toggles every bit between 0 and 1. //Even3 changes every bit from 0 to 1 to 2 and then start over again. int Tile::Dither_color(int color, int xEven, int yEven, int xEven3, int yEven3) { switch(color) { case WHITE: break; case BLACK: break; case BROWN: break; case YELLOW: color = WHITE50_BROWN25_BLACK25; break; case ORANGE: color = WHITE50_BROWN50; break; case RED_ORANGE: color = GREEN25_BROWN75; break; case RED: color = BROWN; break; case DARK_RED: color = BLACK; break; case BLUE: color = WHITE75_BLUE25; break; case DARK_BLUE: color = BLUE; break; case GREEN: color = WHITE50_GREEN50; break; case DARK_GREEN: color = GREEN; break; } //For simple color return immediatley: if(color <= RED_ORANGE) { return color; } // For pseudo color generate dithering pattern: switch(color) { //Light Green: Combinations of White and Green ------------------ case WHITE75_GREEN25: // 75% WHITE and 25% GREEN if((yEven == 1) ∥ (xEven == 1) ) { color = WHITE; } else { color = GREEN; } break; case WHITE50_GREEN50: // 50% WHITE and 50% GREEN if(yEven == xEven) { color = WHITE; } else { color = GREEN; } break; case WHITE25_GREEN75: // 25% WHITE and 75% GREEN if((yEven == 1) && (xEven == 1) ) { color = WHITE; } else { color = GREEN; } break; case BLACK25_GREEN75: // 25% BLACK and 75% GREEN if((yEven == 1) && (xEven == 1) ) { color = BLACK; } else { color = GREEN; } break; //Light Blue: Combinations of White and Blue -------------------- case WHITE75_BLUE25: // 75% WHITE and 25% BLUE if((yEven == 1) ∥ (xEven == 1) ) { color = WHITE; } else { color = BLUE; } break; case WHITE50_BLUE50: // 50% WHITE and 50% BLUE if(yEven == xEven) { color = WHITE; } else { color = BLUE; } break; case WHITE25_BLUE75: // 25% WHITE and 75% BLUE if((yEven == 1) && (xEven == 1) ) { color = WHITE; } else { color = BLUE; } break; case BLACK25_BLUE75: // 25% BLACK and 75% BLUE if((yEven == 1) && (xEven == 1) ) { color = BLACK; } else { color = BLUE; } break; //Light Black: Combinations of White and blacK ------------------ case WHITE75_BLACK25: // 75% WHITE and 25% BLACK if((yEven == 1) ∥ (xEven == 1) ) { color = WHITE; } else { color = BLACK; } break; case WHITE50_BLACK50: // 50% WHITE and 50% BLACK if(yEven == xEven) { color = WHITE; } else { color = BLACK; } break; case WHITE25_BLACK75: // 25% WHITE and 75% BLACK if((yEven == 1) && (xEven ==1) ) { color = WHITE; } else { color = BLACK; } break; //Light Brown: Combinations of White and browN ------------------ case WHITE75_BROWN25: // 75% WHITE and 25% BROWN if((yEven == 1) ∥ (xEven == 1) ) { color = WHITE; } else { color = BROWN; } break; case WHITE50_BROWN50: // 50% WHITE and 50% BROWN if(yEven == xEven) { color = WHITE; } else { color = BROWN; } break; case WHITE25_BROWN75: // 25% WHITE and 75% BROWN if((yEven == 1) && (xEven == 1) ) { color = WHITE; } else { color = BROWN; } break; case WHITE62_BROWN38: // 37.5% BROWN and 62.5% WHITE if(yEven3 == xEven3 ∥ (yEven3 + xEven3 == 2)) { color = BROWN; } else { color = WHITE; } break; case WHITE67_BROWN33: // 33% BROWN and 67% WHITE if(yEven3 == xEven3) { color = BROWN; } else { color = WHITE; if(yEven3 == 0 && xEven3 == 1) { color = BROWN; } } break; case WHITE50_BROWN25_BLACK25: // 25% BROWN, 25% BLACK and 50% WHITE if((yEven == xEven) ) { color = BROWN; if (yEven == 1) { color = BLACK; } } else { color = WHITE; } break; case BLACK50_BROWN50: // 50% BLACK and 50% BROWN if(yEven == xEven) { color = BLACK; } else { color = BROWN; } break; //Combination of Green and browN: -------------------- case GREEN75_BROWN25: // 75% GREEN and 25% BROWN if((yEven == 1) || (xEven == 1) ) { color = GREEN; } else { color = BROWN; } break; case GREEN50_BROWN50: // 50% GREEN and 50% BROWN if(yEven == xEven) { color = GREEN; } else { color = BROWN; } break; case GREEN25_BROWN75: // 25% GREEN and 75% BROWN if((yEven == 1) && (xEven == 1) ) { color = GREEN; } else { color = BROWN; } break; } return color;
[0063] The following is a list of reference characters and variable values used:
[0064] B ij Block of a b Pixel; B ij ∈ G,
[0065] a Number of pixels of a row of a block B ij ,
[0066] b Number of pixels of a column of a block B ij ,
[0067] G Graphic to be displayed or decomposed,
[0068] i Running row index of the graphic to be decomposed into blocks B ij ,
[0069] j Running column index of the graphic to be decomposed into blocks B ij ,
[0070] n Number of pixels of a row of the graphic to be displayed,
[0071] m Number of pixels of a column of the graphic to be displayed,
[0072] N Number of blocks B ij of a row of the graphic to be decomposed, and
[0073] M Number of blocks B ij of a column of the graphic to be decomposed.
[0074] The following is a list of the acronyms used:
[0075] TFT Display Thin Film Transistor Display. | Displaying a graphics such as for example a diagram or a map on a display unit of a portable device requires a reduction in the number of pixels. In each case this requires a decomposition of the graphic into a number of blocks. To do this each block is usually subjected to what is known as “subsampling°. In such cases the semantically important contours disappear at least partly so that the content of the graphic is lost. To resolve this problem to a method is proposed which for a specific application assigns a weighting to the colors underlying the contours. For the reduction in dominant color is determined depending on the result of the weighting and this is simulated in a further procedural step from a set of specified basic and pseudo colors. In this way the semantically important contours of a graphic and thereby the readability are retained despite the fact that reduction has been undertaken. | 6 |
FIELD OF DISCLOSURE
Embodiments of the invention relate to optimizing signaling load overhead and battery consumption for background applications.
BACKGROUND
Wireless communication systems have developed through various generations, including a first-generation analog wireless phone service (1G), a second-generation (2G) digital wireless phone service (including interim 2.5G and 2.75G networks) and a third-generation (3G) high speed data, Internet-capable wireless service. There are presently many different types of wireless communication systems in use, including Cellular and Personal Communications Service (PCS) systems. Examples of known cellular systems include the cellular Analog Advanced Mobile Phone System (AMPS), and digital cellular systems based on Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), the Global System for Mobile access (GSM) variation of TDMA, and newer hybrid digital communication systems using both TDMA and CDMA technologies.
The method for providing CDMA mobile communications was standardized in the United States by the Telecommunications Industry Association/Electronic Industries Association in TIA/EIA/IS-95-A entitled “Mobile Station-Base Station Compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular System,” referred to herein as IS-95. Combined AMPS & CDMA systems are described in TIA/EIA Standard IS-98. Other communications systems are described in the IMT-2000/UM, or International Mobile Telecommunications System 2000/Universal Mobile Telecommunications System, standards covering what are referred to as wideband CDMA (W-CDMA), CDMA2000 (such as CDMA2000 1xEV-DO standards, for example) or TD-SCDMA.
Mobile devices, such as “Smartphones,” tablets, laptops, etc., may have several applications (“apps”) running simultaneously that need to update dynamically (e.g. Twitter®, Facebook®, Yahoo! Finance®, etc.). Each application updates its content periodically based on its own implementation-specific timing. These updates are performed even though the updated content may not be used by the user immediately. Further, these updates are not coordinated across the applications, leading to more frequent radio connections, which results in increased signaling load and/or battery consumption.
SUMMARY
The disclosure relates to managing applications configured for execution on a mobile device. An embodiment of the disclosure receives one or more network access requests from one or more applications executing on the mobile device, determines that the mobile device is operating in a background mode, suppresses transmission to a network of the one or more network access requests to a network based on the determination, and transmits a subset of the one or more network access requests upon transition out of the background mode.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are presented to aid in the description of embodiments of the invention and are provided solely for illustration of the embodiments and not limitation thereof.
FIG. 1 is a diagram of a wireless network architecture that supports access terminals and access networks in accordance with at least one embodiment of the invention.
FIG. 2 illustrates an example of the wireless communications system of FIG. 1 in more detail.
FIG. 3 illustrates a user equipment (UE) in accordance with at least one embodiment of the invention.
FIG. 4 illustrates a communication device that includes logic configured to perform functionality.
FIG. 5 illustrates a method according to an embodiment of the invention.
FIG. 6 illustrates an exemplary embodiment of the invention.
FIG. 7 illustrates an exemplary embodiment of the invention.
FIG. 8 illustrates an exemplary timeline of an embodiment of the invention.
FIG. 9 illustrates an exemplary embodiment of the invention.
FIG. 10 illustrates a method according to an embodiment of the invention.
FIG. 11 illustrates an exemplary embodiment of the invention.
FIG. 12 illustrates test results of an embodiment of the invention.
FIG. 13 illustrates test results of an embodiment of the invention.
FIG. 14 illustrates test results of an embodiment of the invention.
FIG. 15 illustrates test results of an embodiment of the invention.
DETAILED DESCRIPTION
Aspects of the invention are disclosed in the following description and related drawings directed to specific embodiments of the invention. Alternate embodiments may be devised without departing from the scope of the invention. Additionally, well-known elements of the invention will not be described in detail or will be omitted so as not to obscure the relevant details of the invention.
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. Likewise, the term “embodiments of the invention” does not require that all embodiments of the invention include the discussed feature, advantage or mode of operation.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments 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,” “comprising,” “includes,” and/or “including,” when used herein, 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.
Further, many embodiments are described in terms of sequences of actions to be performed by, for example, elements of a computing device. It will be recognized that various actions described herein can be performed by specific circuits (e.g., application specific integrated circuits (ASICs)), by program instructions being executed by one or more processors, or by a combination of both. Additionally, these sequence of actions described herein can be considered to be embodied entirely within any form of computer readable storage medium having stored therein a corresponding set of computer instructions that upon execution would cause an associated processor to perform the functionality described herein. Thus, the various aspects of the invention may be embodied in a number of different forms, all of which have been contemplated to be within the scope of the claimed subject matter. In addition, for each of the embodiments described herein, the corresponding form of any such embodiments may be described herein as, for example, “logic configured to” perform the described action. (e.g., described in more detail below with respect to FIG. 4 ).
A High Data Rate (HDR) subscriber station, referred to herein as user equipment (UE), may be mobile or stationary, and may communicate with one or more access points (APs), which may be referred to as Node Bs. A UE transmits and receives data packets through one or more of the Node Bs to a Radio Network Controller (RNC). The Node Bs and RNC are parts of a network called a radio access network (RAN). A radio access network can transport voice and data packets between multiple access terminals.
The radio access network may be further connected to additional networks outside the radio access network, such core network including specific carrier related servers and devices and connectivity to other networks such as a corporate intranet, the Internet, public switched telephone network (PSTN), a Serving General Packet Radio Services (GPRS) Support Node (SGSN), a Gateway GPRS Support Node (GGSN), and may transport voice and data packets between each UE and such networks. A UE that has established an active traffic channel connection with one or more Node Bs may be referred to as an active UE, and can be referred to as being in a traffic state. A UE that is in the process of establishing an active traffic channel (TCH) connection with one or more Node Bs can be referred to as being in a connection setup state. A UE may be any data device that communicates through a wireless channel or through a wired channel. A UE may further be any of a number of types of devices including but not limited to PC card, compact flash device, external or internal modem, or wireless or wireline phone. The communication link through which the UE sends signals to the Node B(s) is called an uplink channel (e.g., a reverse traffic channel, a control channel, an access channel, etc.). The communication link through which Node B(s) send signals to a UE is called a downlink channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.). As used herein the term traffic channel (TCH) can refer to either an uplink/reverse or downlink/forward traffic channel.
FIG. 1 illustrates a block diagram of one exemplary embodiment of a wireless communications system 100 in accordance with at least one embodiment of the invention. System 100 can contain UEs, such as cellular telephone 102 , in communication across an air interface 104 with an access network or radio access network (RAN) 120 that can connect the UE 102 to network equipment providing data connectivity between a packet switched data network (e.g., an intranet, the Internet, and/or core network 126 ) and the UEs 102 , 108 , 110 , 112 . As shown here, the UE can be a cellular telephone 102 , a personal digital assistant 108 , a pager 110 , which is shown here as a two-way text pager, or even a separate computer platform 112 that has a wireless communication portal. Embodiments of the invention can thus be realized on any form of UE including a wireless communication portal or having wireless communication capabilities, including without limitation, wireless modems, PCMCIA cards, personal computers, telephones, or any combination or sub-combination thereof. Further, as used herein, the term “UE” in other communication protocols (i.e., other than W-CDMA) may be referred to interchangeably as an “access terminal,” “AT,” “wireless device,” “client device,” “mobile terminal,” “mobile station” and variations thereof.
Referring back to FIG. 1 , the components of the wireless communications system 100 and interrelation of the elements of the exemplary embodiments of the invention are not limited to the configuration illustrated. System 100 is merely exemplary and can include any system that allows remote UEs, such as wireless client computing devices 102 , 108 , 110 , 112 to communicate over-the-air between and among each other and/or between and among components connected via the air interface 104 and RAN 120 , including, without limitation, core network 126 , the Internet, PSTN, SGSN, GGSN and/or other remote servers.
The RAN 120 controls messages (typically sent as data packets) sent to a RNC 122 . The RNC 122 is responsible for signaling, establishing, and tearing down bearer channels (i.e., data channels) between a Serving General Packet Radio Services (GPRS) Support Node (SGSN) and the UEs 102 / 108 / 110 / 112 . If link layer encryption is enabled, the RNC 122 also encrypts the content before forwarding it over the air interface 104 . The function of the RNC 122 is well-known in the art and will not be discussed further for the sake of brevity. The core network 126 may communicate with the RNC 122 by a network, the Internet and/or a public switched telephone network (PSTN). Alternatively, the RNC 122 may connect directly to the Internet or external network. Typically, the network or Internet connection between the core network 126 and the RNC 122 transfers data, and the PSTN transfers voice information. The RNC 122 can be connected to multiple Node Bs 124 . In a similar manner to the core network 126 , the RNC 122 is typically connected to the Node Bs 124 by a network, the Internet and/or PSTN for data transfer and/or voice information. The Node Bs 124 can broadcast data messages wirelessly to the UEs, such as cellular telephone 102 . The Node Bs 124 , RNC 122 and other components may form the RAN 120 , as is known in the art. However, alternate configurations may also be used and the invention is not limited to the configuration illustrated. For example, in another embodiment the functionality of the RNC 122 and one or more of the Node Bs 124 may be collapsed into a single “hybrid” module having the functionality of both the RNC 122 and the Node B(s) 124 .
FIG. 2 illustrates an example of the wireless communications system 100 of FIG. 1 in more detail. In particular, referring to FIG. 2 , UEs 1 . . . N are shown as connecting to the RAN 120 at locations serviced by different packet data network end-points. The illustration of FIG. 2 is specific to W-CDMA systems and terminology, although it will be appreciated how FIG. 2 could be modified to conform with various other wireless communications protocols (e.g., LTE, EV-DO, UMTS, etc.) and the various embodiments are not limited to the illustrated system or elements.
UEs 1 and 3 connect to the RAN 120 at a portion served by a first packet data network end-point 162 (e.g., which may correspond to SGSN, GGSN, PDSN, a home agent (HA), a foreign agent (FA), etc.). The first packet data network end-point 162 in turn connects, via the routing unit 188 , to the Internet 175 and/or to one or more of an authentication, authorization and accounting (AAA) server 182 , a provisioning server 184 , an Internet Protocol (IP) Multimedia Subsystem (IMS)/Session Initiation Protocol (SIP) Registration Server 186 and/or the application server 170 . UEs 2 and 5 . . . N connect to the RAN 120 at a portion served by a second packet data network end-point 164 (e.g., which may correspond to SGSN, GGSN, PDSN, FA, HA, etc.). Similar to the first packet data network end-point 162 , the second packet data network end-point 164 in turn connects, via the routing unit 188 , to the Internet 175 and/or to one or more of the AAA server 182 , a provisioning server 184 , an IMS/SIP Registration Server 186 and/or the application server 170 . UE 4 connects directly to the Internet 175 , and through the Internet 175 can then connect to any of the system components described above.
Referring to FIG. 2 , UEs 1 , 3 and 4 . . . N are illustrated as wireless cell-phones, UE 2 is illustrated as a wireless tablet- and/or laptop PC However, in other embodiments, it will be appreciated that the wireless communication system 100 can connect to any type of UE, and the examples illustrated in FIG. 2 are not intended to limit the types of UEs that may be implemented within the system.
Referring to FIG. 3 , a UE 200 , (here a wireless device), such as a cellular telephone, has a platform 202 that can receive and execute software applications, data and/or commands transmitted from the RAN 120 that may ultimately come from the core network 126 , the Internet and/or other remote servers and networks. The platform 202 can include a transceiver 206 operably coupled to an application specific integrated circuit (“ASIC” 208 ), or other processor, microprocessor, logic circuit, or other data processing device. The ASIC 208 or other processor executes the application programming interface (“API’) 210 layer that interfaces with any resident programs in the memory 212 of the wireless device. The memory 212 can be comprised of read-only or random-access memory (RAM and ROM), EEPROM, flash cards, or any memory common to computer platforms. The platform 202 also can include a local database 214 that can hold applications not actively used in memory 212 . The local database 214 is typically a flash memory cell, but can be any secondary storage device as known in the art, such as magnetic media, EEPROM, optical media, tape, soft or hard disk, or the like. The internal platform 202 components can also be operably coupled to external devices such as antenna 222 , display 224 , push-to-talk button 228 and keypad 226 among other components, as is known in the art.
Accordingly, an embodiment of the invention can include a UE including the ability to perform the functions described herein. As will be appreciated by those skilled in the art, the various logic elements can be embodied in discrete elements, software modules executed on a processor or any combination of software and hardware to achieve the functionality disclosed herein. For example, ASIC 208 , memory 212 , API 210 and local database 214 may all be used cooperatively to load, store and execute the various functions disclosed herein and thus the logic to perform these functions may be distributed over various elements. Alternatively, the functionality could be incorporated into one discrete component. Therefore, the features of the UE 200 in FIG. 3 are to be considered merely illustrative and the invention is not limited to the illustrated features or arrangement.
The wireless communication between the UE 102 or 200 and the RAN 120 can be based on different technologies, such as code division multiple access (CDMA), W-CDMA, time division multiple access (TDMA), frequency division multiple access (FDMA), Orthogonal Frequency Division Multiplexing (OFDM), the Global System for Mobile Communications (GSM), 3GPP Long Term Evolution (LTE), or other protocols that may be used in a wireless communications network or a data communications network. Accordingly, the illustrations provided herein are not intended to limit the embodiments of the invention and are merely to aid in the description of aspects of embodiments of the invention.
FIG. 4 illustrates a communication device 400 that includes logic configured to perform functionality. The communication device 400 can correspond to any of the above-noted communication devices, including but not limited to UEs 102 , 108 , 110 , 112 or 200 , Node Bs or base stations 120 , the RNC or base station controller 122 , a packet data network end-point (e.g., SGSN 160 , GGSN 165 , a Mobility Management Entity (MME) in Long Term Evolution (LTE), etc.), any of the servers 170 through 186 , etc. Thus, communication device 400 can correspond to any electronic device that is configured to communicate with (or facilitate communication with) one or more other entities over a network.
Referring to FIG. 4 , the communication device 400 includes logic configured to receive and/or transmit information 405 . In an example, if the communication device 400 corresponds to a wireless communications device (e.g., UE 200 , Node B 124 , etc.), the logic configured to receive and/or transmit information 405 can include a wireless communications interface (e.g., Bluetooth, WiFi, 2G, 3G, etc.) such as a wireless transceiver and associated hardware (e.g., an RF antenna, a MODEM, a modulator and/or demodulator, etc.). In another example, the logic configured to receive and/or transmit information 405 can correspond to a wired communications interface (e.g., a serial connection, a USB or Firewire connection, an Ethernet connection through which the Internet 175 can be accessed, etc.). Thus, if the communication device 400 corresponds to some type of network-based server (e.g., SGSN 160 , GGSN 165 , application server 170 , etc.), the logic configured to receive and/or transmit information 405 can correspond to an Ethernet card, in an example, that connects the network-based server to other communication entities via an Ethernet protocol. In a further example, the logic configured to receive and/or transmit information 405 can include sensory or measurement hardware by which the communication device 400 can monitor its local environment (e.g., an accelerometer, a temperature sensor, a light sensor, an antenna for monitoring local RF signals, etc.). The logic configured to receive and/or transmit information 405 can also include software that, when executed, permits the associated hardware of the logic configured to receive and/or transmit information 405 to perform its reception and/or transmission function(s). However, the logic configured to receive and/or transmit information 405 does not correspond to software alone, and the logic configured to receive and/or transmit information 405 relies at least in part upon hardware to achieve its functionality.
Referring to FIG. 4 , the communication device 400 further includes logic configured to process information 410 . In an example, the logic configured to process information 410 can include at least a processor. Example implementations of the type of processing that can be performed by the logic configured to process information 410 includes but is not limited to performing determinations, establishing connections, making selections between different information options, performing evaluations related to data, interacting with sensors coupled to the communication device 400 to perform measurement operations, converting information from one format to another (e.g., between different protocols such as .wmv to .avi, etc.), and so on. For example, the processor included in the logic configured to process information 410 can correspond to a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. The logic configured to process information 410 can also include software that, when executed, permits the associated hardware of the logic configured to process information 410 to perform its processing function(s). However, the logic configured to process information 410 does not correspond to software alone, and the logic configured to process information 410 relies at least in part upon hardware to achieve its functionality.
Referring to FIG. 4 , the communication device 400 further includes logic configured to store information 415 . In an example, the logic configured to store information 415 can include at least a non-transitory memory and associated hardware (e.g., a memory controller, etc.). For example, the non-transitory memory included in the logic configured to store information 415 can correspond to RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. The logic configured to store information 415 can also include software that, when executed, permits the associated hardware of the logic configured to store information 415 to perform its storage function(s). However, the logic configured to store information 415 does not correspond to software alone, and the logic configured to store information 415 relies at least in part upon hardware to achieve its functionality.
Referring to FIG. 4 , the communication device 400 further optionally includes logic configured to present information 420 . In an example, the logic configured to display information 420 can include at least an output device and associated hardware. For example, the output device can include a video output device (e.g., a display screen, a port that can carry video information such as USB, HDMI, etc.), an audio output device (e.g., speakers, a port that can carry audio information such as a microphone jack, USB, HDMI, etc.), a vibration device and/or any other device by which information can be formatted for output or actually outputted by a user or operator of the communication device 400 . For example, if the communication device 400 corresponds to UE 200 as shown in FIG. 3 , the logic configured to present information 420 can include the display 224 . In a further example, the logic configured to present information 420 can be omitted for certain communication devices, such as network communication devices that do not have a local user (e.g., network switches or routers, remote servers, etc.). The logic configured to present information 420 can also include software that, when executed, permits the associated hardware of the logic configured to present information 420 to perform its presentation function(s). However, the logic configured to present information 420 does not correspond to software alone, and the logic configured to present information 420 relies at least in part upon hardware to achieve its functionality.
Referring to FIG. 4 , the communication device 400 further optionally includes logic configured to receive local user input 425 . In an example, the logic configured to receive local user input 425 can include at least a user input device and associated hardware. For example, the user input device can include buttons, a touch-screen display, a keyboard, a camera, an audio input device (e.g., a microphone or a port that can carry audio information such as a microphone jack, etc.), and/or any other device by which information can be received from a user or operator of the communication device 400 . For example, if the communication device 400 corresponds to UE 200 as shown in FIG. 3 , the logic configured to receive local user input 425 can include the display 224 (if implemented a touch-screen), keypad 226 , etc. In a further example, the logic configured to receive local user input 425 can be omitted for certain communication devices, such as network communication devices that do not have a local user (e.g., network switches or routers, remote servers, etc.). The logic configured to receive local user input 425 can also include software that, when executed, permits the associated hardware of the logic configured to receive local user input 425 to perform its input reception function(s). However, the logic configured to receive local user input 425 does not correspond to software alone, and the logic configured to receive local user input 425 relies at least in part upon hardware to achieve its functionality.
Referring to FIG. 4 , while the configured logics of 405 through 425 are shown as separate or distinct blocks in FIG. 4 , it will be appreciated that the hardware and/or software by which the respective configured logic performs its functionality can overlap in part. For example, any software used to facilitate the functionality of the configured logics of 405 through 425 can be stored in the non-transitory memory associated with the logic configured to store information 415 , such that the configured logics of 405 through 425 each performs their functionality (i.e., in this case, software execution) based in part upon the operation of software stored by the logic configured to store information 405 . Likewise, hardware that is directly associated with one of the configured logics can be borrowed or used by other configured logics from time to time. For example, the processor of the logic configured to process information 410 can format data into an appropriate format before being transmitted by the logic configured to receive and/or transmit information 405 , such that the logic configured to receive and/or transmit information 405 performs its functionality (i.e., in this case, transmission of data) based in part upon the operation of hardware (i.e., the processor) associated with the logic configured to process information 410 .
It will be appreciated that the configured logic or “logic configured to” in the various blocks are not limited to specific logic gates or elements, but generally refer to the ability to perform the functionality described herein (either via hardware or a combination of hardware and software). Thus, the configured logics or “logic configured to” as illustrated in the various blocks are not necessarily implemented as logic gates or logic elements despite sharing the word “logic.” Other interactions or cooperation between the logic in the various blocks will become clear to one of ordinary skill in the art from a review of the embodiments described below in more detail.
A mobile device may have three types of applications that require periodic updates. The first type of application uses application-initiated update sessions, i.e. “pull” services. Examples include Facebook®, Twitter®, Yahoo! Finance®, etc. The second type of application has network-initiated update sessions, i.e. “push” services. An example would be an email service. The third type of application must update at periodic intervals because the network expects it to, i.e. “keep-alive” services. An example would be an instant messaging application. Standby time enhancements for the first type of application can be device-based, while enhancements for the other two types of applications may benefit from network assistance.
An embodiment of the invention defines a background mode and a non-background mode for a mobile device, and defines a new behavior for a mobile device operating in background mode that reduces signaling load overhead and battery consumption by synchronizing application updates.
A mobile device enters “background mode” when there has been no modem data activity for a predefined duration of time, no user interaction (e.g. no key-presses, the display is off, the camera is off, etc.) for a predefined period of time, and the mobile device is not in “tethered” mode (i.e. not connected to an external device such as a laptop). The mobile device may determine that it may enter background mode by determining that there was no peripheral access (e.g. from the keypad, display, accessories, etc.) and no data activity for a certain period of time. If the mobile device is not in background mode, it is in foreground mode.
When the mobile device is in foreground mode, there is no modification to application update requests. When in background mode, however, the mobile device may take steps to reduce signaling load overhead and battery consumption by synchronizing application updates. For example, the mobile device may hold all socket creation requests until the next “wakeup” period. In another example, the mobile device may block or drop any socket connections during a “radio gate off” period. In another example, the mobile device's high-level operating system (“HLOS”) may invoke registered applications when the device “wakes up” (i.e. enters foreground mode), permitting them to connect to the network. In another example, the HLOS may provide registered applications with a given update rate, requiring them to maintain their own update timer.
FIG. 5 illustrates a method 500 for optimizing signaling load overhead and battery consumption for background applications, according to an embodiment of the invention. In an exemplary embodiment of the invention, QUALCOMM'S® Connectivity Engine (“CnE”) may implement method 500 . Alternatively, any connectivity manager running on the mobile device, or the HLOS, may implement method 500 .
At 505 , the mobile device receives a request from an application to access the network, such as an update request. For example, the request may be a request to open a socket (e.g. a Connect( ) method) as shown in FIG. 6 . In another example, the request may be a synchronization request after a socket has been created (e.g. SYN packets) as shown in FIG. 7 . In yet another example, the request may be a callback function registration as shown in FIG. 9 .
At 510 , the mobile device determines whether or not it is in background mode. As discussed above, when the mobile device determines that there has been no modem data activity for a predefined duration of time, no user interaction with the device for a predefined period of time, and the mobile device is not in “tethered” mode, it enters background mode. “Tethered” mode is when an external device connects to the mobile device either through a wireline or a wireless connection to use the mobile device's connectivity to the cellular operator as the backhaul. As an example of how the mobile device may determine that it is in background mode, the mobile device may set a “wakeup” timer when it enters background mode. When the wakeup timer expires, the device switches to foreground mode, as shown in FIG. 9 . In that way, the wakeup timer defines the period of time the mobile device will spend in background mode. If the mobile device “wakes up” before the expiration of the wakeup timer, due to user input or network activity, for example, the mobile device may stop the timer then reset it when it returns to background mode. Thus, in order to determine whether or not the mobile device is in background mode, the mobile device may simply check whether or not the wakeup timer is still running. When the mobile device wakes up, the mobile device processes the queued requests and forwards them to the network.
In another example, the mobile device may additionally or alternatively define a radio “gate on/off” period, as shown in FIGS. 6 and 7 . The radio gate is “on” when the mobile device is in foreground mode and “off” when the mobile device is in background mode. The mobile device may define a particular period of time that the radio gate should be off. The mobile device can check whether the gate is “on” or “off” in order to determine whether the mobile device is in background mode. If the mobile device is not in background mode, the mobile device permits the application to access the network at 525 .
At 515 , if the mobile device is in background mode, the mobile device synchronizes the application request with a predefined wakeup schedule. For example, the mobile device may hold all socket open requests until the mobile device enters foreground mode at the beginning of a “gate on” period, as shown in FIG. 6 , or the expiration of the wakeup timer. In another example, the mobile device may block or drop all socket connections while the device is in background mode, i.e. during a “gate off” period as shown in FIG. 7 , or until the expiration of the wakeup timer. In another example, the mobile device may register the callback function received from the application, as shown in FIG. 9 . In this example, the mobile device may register the callback function before or after determining that it is in background mode.
At 520 , the mobile device “wakes up” and enters foreground mode. The mobile device may wake up due to the expiration of the wakeup timer or due to user or network activity. Upon entering foreground mode, the mobile device may stop the wakeup timer (if not expired) and/or set the radio gate to “on.”
At 525 , the mobile device permits any application to access the network. For example, the mobile device may release the socket open requests it had been holding, as shown in FIG. 6 . In another example, the mobile device may stop blocking or dropping socket connections, as shown in FIG. 7 . In another example, the mobile device may invoke the applications that registered callback functions, as shown in FIG. 9 . The mobile device permits all network access requests during the foreground period. At the expiration of the foreground period, or due to inactivity, the mobile device reenters background mode, and method 500 may repeat.
FIG. 6 illustrates an exemplary embodiment of the invention whereby the mobile device holds all socket open requests until the mobile device enters foreground mode. FIG. 6 shows QUALCOMM'S® CnE wrapper 605 controlling access requests from various applications A and B ( 601 a and 601 b , respectively), but it will be apparent that any connectivity manager could perform the function of the CnE wrapper 605 .
In FIG. 6 , the CnE wrapper 605 initially sets a “gate off” period 610 (the CnE wrapper 605 may also, or alternatively, start a wakeup timer, as discussed above). This “gate off” period 610 corresponds to the mobile device being in background mode. During the “gate off” period 610 , the CnE wrapper 605 intercepts all socket open requests, e.g. Connect( ) methods 602 a , and holds ( 615 ) them until the mobile device “wakes up” (i.e. enters the foreground mode) and transitions to a “gate on” period 620 . The start of the “gate on” period 620 may be due to the expiration of the wakeup timer or due to user or network initiated data. During the “gate on” period 620 , the CnE wrapper 605 passes any socket open requests (e.g. 602 b ), including the socket requests that it had been holding (e.g. 602 a ), to the socket library 607 and TCP/IP stack. The TCP/IP layer 608 then transmits the requests (now, e.g., SYN requests 603 a and 603 b ) to the network 104 , without further involving the CnE driver 609 .
The CnE wrapper 605 may “hold” the socket open requests 602 a at 615 by, for example, freezing the application threads. Then, when the mobile device enters foreground mode, i.e. the “gate on” period 620 , the CnE wrapper 605 releases the application threads so that they may continue executing.
FIG. 7 illustrates an exemplary embodiment of the invention whereby the mobile device drops socket connections during a “radio gate off” period. FIG. 7 shows QUALCOMM'S® CnE driver 709 controlling access requests from various applications A and B ( 701 a and 701 b , respectively), but it will be apparent that any connectivity manager could perform the function of the CnE driver 709 .
In FIG. 7 , the CnE driver 709 initially sets a “gate off” period 710 (the CnE wrapper 705 may also, or alternatively, start a wakeup timer, as discussed above). This “gate off” period 710 corresponds to the mobile device being in background mode. The CnE driver 709 intercepts outgoing synchronization packets, e.g. SYN requests 703 a from Connect( ) 702 a , and drops them ( 715 ), but forwards any other type of packet (leading to a radio connection being established). When the mobile device “wakes up,” whether because the “gate off” period 710 expired or it was interrupted by user or network initiated data, the CnE driver 709 transitions to a “gate on” period 720 , i.e. foreground mode. All packets received during the “gate on” period 720 , such as SYN request 703 b from Connect( ) 702 b , pass through CnE wrapper 705 , socket library 707 , TCP/IP 708 , and are forwarded to the network 104 . Any synchronization packets received during the “gate off” period 710 , however, are not forwarded. The CnE driver 709 sets another “gate off” period at 725 .
As shown in FIG. 8 , the “gate off” period 710 or wakeup timer in FIG. 7 may be modified after every wakeup cycle to ensure the successful update, over time, of all applications. That is, only a fraction of the application-initiated updates will be successful during a given “gate off” period 710 . For example, with the 30 minute “gate off” period shown in FIG. 8 , application A 701 a fails to update but application B 701 b succeeds at the next wakeup. The result is the same for the 28 minute “gate off” period. However, after the 26 minute “gate off” period, application A 701 a successfully updates, while application B 701 b fails to update. The mobile device can continue changing the “gate off” period until an optimal period is determined. Although FIG. 8 shows decreasing “gate off” intervals, it will be apparent that increasing intervals are also possible. The timing is chosen in such a way that over a large time period, all the applications will be able to transmit the data. The choice of the gate-on/gate-off period may be derived based on the timing periodicity registered by different applications.
FIG. 9 illustrates an embodiment of the invention whereby the HLOS 905 invokes registered applications and permits them to connect to the network upon the expiration of a wakeup timer. Exemplary applications A and B ( 901 a and 901 b , respectively) register callback functions 912 a and 912 b with the HLOS 905 . At some point, the HLOS 905 determines that a wakeup timer has expired ( 910 ) and enters the foreground mode. Upon entering the foreground mode, the HLOS 905 invokes applications A and B, 901 a and 901 b , by means of the registered callback functions 913 a and 913 b , respectively. The applications then perform update operations, e.g. sending Connect( ) functions 902 a and 902 b to the HLOS 905 , which sends SYN requests 903 a and 903 b to the network 104 .
FIG. 10 illustrates a method 1000 according to an embodiment of the invention whereby a registered application maintains an update timer and updates according to an HLOS-provided update rate. At 1005 , an application registers with the HLOS and requests a desired update frequency. At 1010 , the HLOS provides the application with its update instants (e.g. update time and frequency). All applications are provided the same update instants adjusted for their desired update frequency. That is, all applications are given the same update time and frequency unless certain applications do not need to update that frequently. For example, a given application may request to update every 12 hours, while the HLOS has determined that all applications should update every two hours. In that situation, the given application would be given an update instant of every 12 hours. On the other hand, if a given application requests to update every hour and the HLOS has determined that all applications should update every two hours, that application will be given an update instant of every two hours. Further, all applications will update at the same time every two hours. For example, the HLOS may determine that each application should update at 12:00 pm, 2:00 pm, 4:00 pm, and so on. Each registered application maintains its own update timer, and at the specified update instants, each application sends update requests to the network ( 1015 ).
FIG. 11 illustrates an example embodiment of the invention whereby an application registers with the HLOS 1105 and is given a particular update rate. Specifically, applications A and B ( 1101 a and 1101 b , respectively) send registration requests 1112 a and 1112 b to the HLOS 1105 . In response, the HLOS 1105 sends applications A and B their respective update instants 1113 a and 1113 b . As described above with respect to FIG. 10 , the update instants for applications A and B may be the same. Applications A and B then set their own wakeup timers to the provided update instants. When the wakeup timers expire at 1110 , applications A and B send update requests (e.g. Connect( ) functions 1102 a and 1102 b ) to the HLOS 1105 . The HLOS 1105 receives the update requests and transmits them to the network (e.g. as SYN requests 1103 a and 1103 b ).
FIGS. 12-15 show the results of testing various embodiments of the invention. Embodiments of the invention were tested on a Smartphone accessing a commercial EV-DO network. The applications tested were an SMS blogging service application, a finance application, and a news feed application, with a preferred refresh rate of every five minutes, a social media application and a weather application, with a preferred refresh rate of every hour, and a voice-over-IP (VoIP) text messaging application and instant messaging application, with variable refresh rates. The test duration was one hour. The network dormancy timer was four seconds. The metrics tracked were the total number of connections, the total connected time, and the average connection duration.
Table 1 below shows four test cases run without using an embodiment of the invention in order to set a baseline. Test Case 1 ran the SMS blogging service application, the social media application, and the VoIP text messaging application. Test Case 2 ran the Test Case 1 applications plus the finance application and the weather application. Test Case 3 ran the Test Case 2 applications plus the news feed application. Test Case 4 ran the Test Case 2 applications plus the instant messaging application.
TABLE 1
Total Connection
Number of
Average Connection
Test Case
Time (sec)
Connections
Time (sec)
1
279.2
35
7.9
2
338.8
43
7.8
3
402.8
55
7.3
4
422.8
61
6.9
As discussed above, embodiments of the invention time-align the connections for background applications. For testing embodiments of the invention, the relevant factors were the number of applications, the percentage of time that the mobile device was actively used, the relative power consumption of active device usage (i.e. foreground mode) versus updates to the same set of applications when in the background (i.e. background mode), and the time-alignment of updates to applications in background mode.
FIG. 12 illustrates the percentage reduction in device power consumption when there was no active device usage. FIG. 13 illustrates the estimated power reduction of combining applications when the device was actively used for five minutes every hour.
Other tests of embodiments of the invention determined the foreground-to-background power consumption ratio. The assumption to be verified was that power consumption during foreground mode was not a strong function of the application used. Running the SMS blogging service application, the social media application, and the finance application in background mode, the average current draw was 320 mA during data activity and approximately 0 mA when there was no data activity. Running a web browser application during foreground mode, the average current draw was 780 mA during data activity and approximately 200 mA when there was no data activity. Thus, the foreground mode to background mode power consumption ratio is approximately 2.5.
FIG. 14 illustrates the estimated power reduction from time aligning application updates in background mode, assuming the mobile device is in foreground mode for five minutes per hour and the foreground-to-background power ratio is 2.5. FIG. 15 illustrates the estimated power reduction of combining applications at 100% alignment, again assuming that the foreground-to-background power ratio is 2.5.
Those of skill in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
Further, those of skill in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The methods, sequences and/or algorithms described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor.
Accordingly, an embodiment of the invention can include a computer readable media embodying a method for optimizing signaling load overhead and battery consumption for background applications. Accordingly, the invention is not limited to illustrated examples and any means for performing the functionality described herein are included in embodiments of the invention.
While the foregoing disclosure shows illustrative embodiments of the invention, it should be noted that various changes and modifications could be made herein without departing from the scope of the invention as defined by the appended claims. The functions, steps and/or actions of the method claims in accordance with the embodiments of the invention described herein need not be performed in any particular order. Furthermore, although elements of the invention may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. | The disclosure relates to managing applications configured for execution on a mobile device. An embodiment of the disclosure receives one or more network access requests from one or more applications executing on the mobile device, determines that the mobile device is operating in a background mode, suppresses transmission to a network of the one or more network access requests to a network based on the determination, and transmits a subset of the one or more network access requests upon transition out of the background mode. | 8 |
CLAIM TO PRIORITY OF EARLIER FILED APPLICATION(S)
This Application claims the benefit of U.S. Provisional application No. 61/806,343 filed on Mar. 28, 2013.
CROSS-REFERENCE TO EARLIER FILED APPLICATION(S)
The disclosure of U.S. Provisional application No. 61/806,343 filed on Mar. 28, 2013 is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to a hands-free illumination device that attaches to the fingers, thus leaving the hands free to perform other tasks.
BACKGROUND OF THE INVENTION
Small portable illumination devices have been a part of the field since the turn of the last century. The problem with these devices is that most must be held by the operator's hand, thus occupying one hand and leaving the other hand to perform a task. This can be awkward for the person using the device. Situations exist where the user doesn't have the luxury of dedicating one hand for illuminating, leaving one hand to perform a task. This embodiment frees the hand to be unhindered and available to complete the work at a higher level of efficiency.
This device has multiple uses for professionals as well as non-professionals. Professionals that would benefit from this device may include, but are not limited to: first responders, such as police, paramedics, and military personnel. Other professionals using the device may include maintenance workers, such as building inspectors, plumbers, electricians, or other professionals, such as delivery personnel, security guards, ushers, etc.
Personal uses may include, but are not limited to: senior citizens (for example those using a walker or cane), handicapped individuals (for example an arm amputee), campers or other outdoorsmen, as well as homeowners. Other uses of this embodiment are ideal in poorly lit environments where safety is an issue. Other uses may include walking while carrying a box or a bag of groceries, as this configuration affords the user a well-lit pathway, or performing home repairs in a low-light environment.
Various illuminating devices have been proposed in the prior art. Many of these are ornamental in nature as in U.S. Pat. Des. 300,260 by Segeren (Mar. 14, 1989), or bulky as in wrist-mounted power sources as in U.S. Pat. No. 5,448,458 by Smyly, Jr. (Sep. 5, 1995), or are of a glove type, which are inconvenient and cumbersome as in U.S. Pat. No. 6,892,397 by Raz et al. (May 17, 2005.)
Even as early as the 1900s a few inventors have come up with finger-mounted electric lamps but they are very bulky in nature as in U.S. Pat. No. 674,770 by Hull (May 21, 1901) and U.S. Pat. No. 914,975 by Radley (Mar. 9, 1909).
One prior art describes a utilitarian-type ring with an integrated lamp socket and bulb and arcuate batteries that were contained within the circumference of the ring as in U.S. Pat. No. 4,012,629 by Simms (Mar. 15, 1977). The Simms invention does not allow for forward illumination, thus limiting the field of vision.
Another prior art describes a reading light ring with an LED as the source of illumination on the palm side of the hand and also is operated by means of a thumb-operated switch as described in U.S. Pat. No. 7,703,937 B2 by Shirey (Apr. 27, 2010). The Shirey device does not allow for forward illumination, thus limiting the field of vision.
SUMMARY OF THE INVENTION
One compact illuminating embodiment designed to be hands-free that attaches to the user's finger(s) via a strap or molded ring at the proximal phalanx bone of the index and middle fingers. The embodiment is a convenient and compact structure composed of a strong, lightweight material, and contains within an illumination source directed forward to maximize and improve the field of vision, a power source, and an ergonomically-located energizing button within easy reach of the thumb.
ADVANTAGES OF THE INVENTION
Accordingly, several advantages of one or more aspects are, as follows: to provide hands-free forward directed illumination while leaving the operator's hand available to perform a task. The embodiment is utilitarian, compact, and novel. Also, different types of light in different combinations make it versatile, as well, as there may be multiple combinations of light and circuitry to meet user needs. For example, white light and UV light for forensics, white light and infrared for the military and pilots, or white light and a laser pointer for presentations. Other advantages of one or more aspects will be apparent from a consideration of the drawings and ensuing descriptions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is substantially a top perspective of the preferred embodiment of the present invention.
FIG. 2 is substantially a side perspective of the preferred embodiment of the present invention.
FIG. 3 is substantially an end perspective of the preferred embodiment of the present invention.
FIG. 4 is substantially a circuit diagram for the preferred embodiment of the present invention.
FIG. 5 is substantially a top perspective of the power supply for the preferred embodiment of the present invention.
FIG. 6 is substantially a top perspective of the breakaway pins for the power supply of the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In the following detailed description of the preferred embodiment, reference is made to the accompanying drawings, which form a part of this application. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
The following is a listing of the reference numbers included in the original drawings and the element that each reference number corresponds to and a brief description:
FIG. 1 :
1 . Light Emitting Element. The Light Emitting Element 1 is mounted to the Base Member 5 in the preferred embodiment.
4 . Switch. The Switch 4 is coupled to the Circuit 2 and is positioned on the first lateral side of the Base member 5 , thereby allowing the Switch 4 to be actuated by the thumb of the hand in the preferred embodiment.
5 . Base Member. The Base Member 5 is connected to the Light Emitting Element 1 , and in the preferred embodiment the Base Member 5 has a top side, a first lateral side, a second lateral side, and a semi-cylindrically curved underside
6 . First Strap. In the preferred embodiment, the First Strap 6 is connected to the Base Member 5 such that the First Strap 6 , together with the semi-cylindrically curved underside of the Base Member 5 , form a first loop, the first loop being sized to the index finger of a hand.
FIG. 2 :
1 . Light Emitting Element. The Light Emitting Element 1 is mounted to the Base Member 5 in the preferred embodiment.
4 . Switch. The Switch 4 is coupled to the Circuit 2 and is positioned on the first lateral side of the Base member 5 , thereby allowing the Switch 4 to be actuated by the thumb of the hand in the preferred embodiment.
5 . Base Member. The Base Member 5 is connected to the Light Emitting Element 1 , and in the preferred embodiment the Base Member 5 has a top side, a first lateral side, a second lateral side, and a semi-cylindrically curved underside
6 . First Strap. In the preferred embodiment, the First Strap 6 is connected to the Base Member 5 such that the First Strap 6 , together with the semi-cylindrically curved underside of the Base Member 5 , form a first loop, the first loop being sized to the index finger of a hand.
FIG. 3 :
1 . Light Emitting Element. The Light Emitting Element 1 is mounted to the Base Member 5 in the preferred embodiment.
5 . Base Member. The Base Member 5 is connected to the Light Emitting Element 1 , and in the preferred embodiment the Base Member 5 has a top side, a first lateral side, a second lateral side, and a semi-cylindrically curved underside
6 . First Strap. In the preferred embodiment, the First Strap 6 is connected to the Base Member 5 such that the First Strap 6 , together with the semi-cylindrically curved underside of the Base Member 5 , form a first loop, the first loop being sized to fit the index finger of a hand.
7 . Second Strap. In the preferred embodiment, the Second Strap 7 is connected to the second lateral side of the Base Member 5 , such that the Second Strap 7 forms a second loop sized to fit the middle finger of a hand.
FIG. 4 :
1 . Light Emitting Element. The Light Emitting Element 1 is mounted to the Base Member 5 in the preferred embodiment.
2 . Circuit. In the preferred embodiment, the Circuit 2 consists of a Light Emitting Element 1 , a Portable Power Supply 3 , and a Switch 4 .
3 . Portable Power Supply. In the preferred embodiment, the Portable Power Supply 3 comprises a battery, is coupled to the Circuit 2 , and is configured to provide electricity to the Circuit 2 . The Portable Power Supply 3 is connected to the Light Emitting Element 1 on one side and to the Switch 4 on the other side.
4 . Switch. In the preferred embodiment, the Switch 4 is coupled to the Circuit 2 , and the Switch 4 is connected to the Light Emitting Element 1 on one side and to the Portable Power Supply 3 on the other side.
FIG. 5 :
3 . Portable Power Supply. In the preferred embodiment, the Portable Power Supply 3 is attached to a Third Strap 9 , which is configured to secure the Portable Power Supply 3 to a wrist of the user, thereby allowing a larger Portable Power Supply 3 to be utilized by the user.
9 . Third Strap. In the preferred embodiment, the Third Strap 9 secures the Portable Power Supply 3 to a wrist of the user, thereby allowing a larger Portable Power Supply 3 to be utilized by the user.
FIG. 6 :
8 . First Breakaway Pin. In the preferred embodiment, the First Breakaway Pin 8 is coupled to a connection point between the Base Member 5 and the First Strap 6 .
11 . Second Breakaway Pin. In the preferred embodiment, the Second Breakaway Pin 11 is coupled to a connection point between the Base Member 5 and the Second Strap 7 .
DISCLAIMER
Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the present invention. | A finger-mounted illuminating device is disclosed. This device specifically addresses the problem of maintaining hands-free capability in a low or no light environment. This embodiment is a compact structure made of sturdy plastic or other material, which is mounted to the finger(s) and contains various types of illumination output, power source, thumb activated button(s), and circuits to manipulate the illumination needs as required by the operator. | 5 |
BACKGROUND OF THE INVENTION
This invention concerns DNA sequences that code for a glycerol-3-phosphate dehydrogenase (GPDH) and the alleles as well as the derivatives of these DNA sequences.
This invention also concerns genomic clones that contain the complete gene of a glycerol-3-phosphate dehydrogenase and alleles as well as derivatives of this gene.
This invention also concerns promoters and other regulator elements of glycerol-3-phosphate dehydrogenase genes.
Glycerol-3-phosphate dehydrogenase (GPDH; EC 1.1.1.8), also known as dihydroxyacetone phosphate reductase, is substantially involved in triacylglyceride biosynthesis in plants by supplying glycerol-3-phosphate. Fatty acid biosynthesis and triacylglyceride biosynthesis can be regarded as separate biosynthesis pathways owing to compartmentalization but as one biosynthesis pathway from the standpoint of the end product. De novo biosynthesis of fatty acids takes place in the plastids and is catalyzed by three enzymes or enzyme systems, i.e., (1) acetyl-CoA carboxylase (ACCase), (2) fatty acid synthase (FAS), and (3) acyl-[ACP]-thioesterase (TE). The end products of this reaction sequence in most organisms are either palmitic acid, stearic acid, or after desaturation, oleic acid.
In the cytoplasm, however, triacylglyceride biosynthesis takes place via the so-called "Kennedy pathway" in the endoplasmic reticulum from glycerol-3-phosphate which is made available by the activity of glycerol-3-phosphate dehydrogenase (S. A. Finnlayson et al., Arch. Biochem. Biophys., 199 (1980) pages 179-185), and from fatty acids present in the form of acyl-CoA substrates.
Probably the first discovery of the enzymatic activity of glycerol-3-phosphate dehydrogenase in plants involved potato tubers (G. T. Santora et al., Arch. Biochem. Biophys., 196 (1979) pages 403-411). This activity had not been observed in other plants before then (B. Konig and E. Heinz, Planta, 118 (1974) pages 159-169), so the existence of the enzyme had not been detected. Thus the formation of glycerol-3-phosphate on the basis of the activity of a glycerol kinase was discussed as an alternative biosynthesis pathway. Santora et al., loc. cit., subsequently detected GPDH in spinach leaves and succeeded in increasing the concentration of the enzyme approximately 10,000 times. They determined the native molecular weight to be 63.5 kDa and found the optimum pH for the reduction of dihydroxyacetone phosphate (DHAP) to be 6.8 to 9.5 for the reverse reaction. GPDH was likewise detected in Ricinus endosperm (Finlayson et al., Biochem. Biophys. 199 (1980) pages 179-185). According to more recent works (Gee et al., Plant Physiol. 86 (1988a) pages 98-103), two GPDH activities could be detected in enriched fractions, a cytoplasmic fraction (20-25%) and a plastid (75-80%) . The two forms are regulated differently. Thus, for example, the cytoplasmic isoform can be activated by F2,6DP, while the plastid isoform is activated by thioredoxin (R. W. Gee et al., Plant Physiol., 86 (1988) pages 98-103 and R. W. Gee et al., Plant Physiol., 87 (1988) pages 379-383).
The methods of molecular biology are making increasing entry into plant cultivation practice. Changes in biosynthesis output with the formation of new components and/or higher yields of these components can be achieved with the help of gene manipulation, e.g., transfer of genes which code for enzymes. As one of the most important enzymes of triacylglyceride synthesis, GPDH has a significant influence on the oil yield of plants.
SUMMARY OF THE INVENTION
It is thus the object of this invention to improve the oil yield of crop plants by influencing the triacylglyceride content.
This object is achieved with the DNA sequences and the genes from the gethomic clones in accordance with the invention.
This invention concerns DNA sequences that code for a glycerol-3-phosphate dehydrogenase, and alleles as well as derivatives of these DNA sequences.
This invention also concerns genomic clones that contain a complete gene of a glycerol-3-phosphate dehydrogenase including the structure gene, the promoter and other regulator sequences, and alleles as well as derivatives of this gene.
This invention likewise concerns the promoters and other regulator elements of glycerol-3-phosphate dehydrogenase genes from the specified genomic clones, and the alleles as well as derivatives of these promoters.
This invention additionally concerns a method of producing plants, plant parts and plant products in which the triacylglyceride content or fatty acid content is altered, where DNA sequences or genes are transferred from the genomic clones by the methods of genetic engineering.
This invention also concerns the use of said DNA sequences or one of the genes originating from said genomic clones for altering the triacylglyceride content or its fatty acid pattern in plants.
Finally, this invention concerns transgenic plants, plant parts and plant products produced according to the aforementioned method.
The figures serve to clarify the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1: Comparison of the derived amino acid sequences SEQ ID NOS:8 and 4 respectively of the ClGPDH30 SEQ ID NO:7 and CLGPDH109 SEQ ID NO:3 cDNAs as well as the amino acid sequence SEQ ID NO:12 from the gene from the ClGPDHg3 (SEQ ID NO:11) genomic clone with the GPDH amino acid sequence of the mouse (Mm GPDH) SEQ ID NO:17;
FIG. 2: Separation of proteins from BB26-36 cells by gel electrophoresis;
FIG. 3: Map of the insertions contained in ClGPDHg5SEQ ID NO:9, ClGPDH9 SEQ ID NO:15 and ClGPDH3 SEQ. ID NO:11 genomic clones with various restriction enzymes;
FIG. 4: Schematic diagram of the functional areas of the genes contained in the ClGPDH5SEQ ID NO:9, ClGPDH9 SEQ ID NO:15 and ClGPDH3 SEQ ID NO:11 genomic clones; and
FIG. 5: Northern Blot with RNAs from various plant tissues, hybridized with ClGPDH20 SEQ ID NO:1 cDNA as a probe.
DESCRIPTION OF THE INVENTION
It follows that allelic variants and derivatives of DNA sequences or genes according to this invention are included within the scope of this invention under the assumption that these modified DNA sequences or modified genes will code for glycerol-3-phosphate dehydrgenase. The allelic variants and derivatives include, for example, deletions, substitutions, insertions, inversions and additions to DNA sequences or genes according to this invention.
Any plant material that produces glycerol-3-phosphate dehydrogenase in sufficient quantities is a suitable raw material for isolating cDNAs that code for glycerol-3-phosphate dehydrogenase. Isolated embryos from the plant Cuphea lanceolata, indigenous to Central America, have proven to be an especially suitable raw material in the present invention.
Functional complementation was used for isolation of DNA sequences according to this invention. This refers to complementation of mutant microorganisms with heterologous cDNA. Functional complementation was performed after infecting E. coli strain BB26-36, which is auxotrophic for glycerol, with phagemids containing plasmids with cDNAs from Cuphea lanceolata. Plasmids isolated from functionally complemented bacteria were cleaved with restriction endonucleases and separated by electrophoresis. The cDNAs contained in the plasmids were classified in two classes that differ in the size of their insertions. Retransformation confirmed that the isolated cDNAs were capable of complementing the BB26-36 mutant.
The complete coding area of one of the two classes codes for a glycerol-3-phosphate dehydrogenase contained in the ClGPDH20 cDNA clone. This is an Eco RI-ApaI fragment that has 1354 base pairs. The complete 1354 base pair DNA sequence of the ClGPDH20 cDNA and the amino acid sequence derived from it are entered in the Sequence Listing as SEQ ID NO:1. ClGPDH20 cDNA was sequenced double stranded. Proceeding from the ATG start codon, the cDNA codes from positions 17 to 1132 for a protein with 372 amino acids SEQ ID NO:1 (ending at the TAG stop codon), which is expressed as a fusion with lacZ without a shift in the reading frame. The estimated molecular weight is 40.8 kDa. Two base pairs (CA) preceding ATG are included with the cDNA. The first 14 nucleotides are attributed to the DNA sequence of the fusion with lacZ, and the linker sequence is indicated at the 3' end. The polyA signal is found at positions 1329 to 1334 in the 3' untranslated region.
It is assumed that ClGPDH20 cDNA SEQ ID NO:1 is a cytoplasmic isoform, because no transit peptide can be detected in homology comparisons with mouse GPDH SEQ ID NO:17 (see FIG. 1). On the basis of the position of an assumed NADH binding site corresponding to the consensus sequence GxGxxG (see positions 29 to 34 in the ClGPDH20 amino acid sequence in FIG. 1 (R. K. Wierenga et al., Biochem. 24 (1985) pages 1346-1357) , the N-terminal sequence of 28 amino acids is not sufficient to code for a transit peptide whose length varies between 32 and 75 amino acids (Y. Gavel et al., FEBS Lett. 261 (1990) pages 455-458).
A cDNA library from Cuphea lanceolata was screened with ClGPDH20 cDNA SEQ ID NO:1 as a probe for isolation of additional GPDH cDNAs, and a total of 52 cDNA clones were isolated. The 18 longest cDNAs were completely or partially sequenced. The ClGPDH109, ClGPDH30 and ClGPDH132 cDNA clones contain cDNAs with the complete coding region or a virtually complete cDNA of GPDH.
The ClGPDH109 cDNA clone contains the complete coding region of GPDH on a 1464 base pair EcoRI-ApaI DNA fragment which codes for a protein with 381 amino acids. The DNA sequence is SEQ ID NO:3, and the amino acid sequence derived from it is shown as SEQ ID NO:4 in the Sequence Listing. The DNA fragment was sequenced double stranded. The coding area begins with the ATG start codon in position 45 and ends in position 1187, followed by the TAG stop codon (positions 1188 to 1190). The cDNA itself begins at position 15. The first 14 nucleotides are attributed to the DNA sequence of the fusion with lacZ. The polyA signal (positions 1414 to 1419) and the polyA area (positions 1446 to 1454) as well as the linker sequence (positions 1459 to 1464) are found in the untranslated region at the 3' end.
Another cDNA, ClGPDH30, also contains the complete coding region of GPDH on a 1390 base pair EcoRI-XhoI fragment, which codes for a protein with 372 amino acids. The double-stranded-sequenced DNA sequence is SEQ ID NO:7 and the protein sequence derived from it is listed as SEQ ID NO:8 in the Sequence Listing. The protein coding sequence begins with the ATG start codon at position 34 and ends before the stop codon at position 1149. The first 14 base pairs are attributed to the sequence of the fusion with lacZ. The polyA signal (positions 1349 to 1354) and the polyA region (positions 1366 to 1384) are found in the untranslated 3' area.
The ClGPDH132 cDNA clone with 1490 base pairs is an Eco RI-XhoI fragment, the DNA sequence of which is SEQ ID NO:5 and the amino acid sequence derived from it is shown as SEQ ID NO:6 in the Sequence Listing. The DNA fragment was sequenced double stranded. ClGPDH132 cDNA SEQ ID NO:5 is missing 14 amino acids at the N terminus in comparison with ClGPDH109 cDNA SEQ ID NO:3. The open reading frame begins at position 15 and ends at position 1115, followed by the stop codon at positions 1116 to 1118. Consequently, ClGPDH132 cDNA SEQ ID NO:5 codes for a protein with 367 amino acids SEQ ID NO:6 and likewise includes the coding area for glycerol-3-phosphate dehydrogenase with the exception of 14 amino acids. The first 14 nucleotides are to be attributed to the lac fusion sequence and the linker sequence (positions 1485 to 1490) is at the 3' end. The polyA signal and the polyA area are located at positions 1343 to 1348 and 1465 to 1484, respectively, in the untranslated 3' area.
Two classes of cDNAs can be distinguished on the basis of sequence data. Accordingly, ClGPDH20 SEQ ID NO:1 and ClGPDH30 SEQ ID NO:7 cDNAs belong to class A and ClGPDH132 SEQ ID NO:5 and ClGPDH109 SEQ ID NO:3 cDNAs belong to class B.
As FIG. 1 shows, the derived amino acid sequences of ClGPDH30 SEQ ID NO:7 and ClGPDH109 SEQ ID NO:3 cDNAs show 96% identical amino acids. At the same time, the derivative amino acid sequences of the cDNAs and those of a gene to be assigned to another class, ClGPDH30SEQ ID NO:7, were compared with the GPDH amino acid sequence of the mouse (MmGPDH SEQ ID NO:17). The differences between the amino acid sequence derived from the ClCPDH109 cDNA SEQ ID NO:3, the coded amino acid sequence of the gene and the mouse GPDH SEQ ID NO:17 in comparison with the amino acid sequence derived from ClGPDH30 SEQ ID NO:7 are shown in black. On the average, the identity of the derivative proteins of the cDNAs and the GPDH gen with the mouse protein SEQ ID NO:17 is approximately 50%.
ClGPDH20 SEQ ID NO:1 cDNA was cloned into an expression vector and expressed in E. coli as a fusion protein with glutathione-S-transferase. To do so, the cDNA was cloned beginning with ATG (see position 17, SEQ ID NO:1) into pGX, a derivative of the PGEXKG expression vector (K. L. Guan et al., Analytical Biochem. 192 (1991) pages 262-267). BB26-36 cells were harvested at various times after administration of IPTG isopropyl-b-thiogalactopyranoside) and their proteins were separated by gel electrophoresis. FIG. 2 shows gel electrophoretic separation of BB26-36 cell extracts. The left column shows the proteins of cells with the pGX expression vector (without fusion; 26 kDa protein) and the right side shows proteins of cells with the pGXGPDH20 expression vector which codes for a fusion protein of 67 kDa. The hourly values given indicate the times of sampling after IPTG induction. This clearly shows an enrichment of the fusion protein after two hours. An enzyme activity determination was subsequently performed by enzyme assay of GPDH with an isolated fusion protein and significant enzyme activity was measured. This finding clearly proves that ClGPDH20 SEQ ID NO:1 cDNA contains a competent gene for expression of GPDH.
Furthermore, genomic clones were isolated, where a library of genomic DNA of Cuphea lanceolata was screened with ClCPDH20 SEQ ID NO:1 cDNA as a probe. By this method, 31 genomic clones were isolated. The genomic clones contain a complete structure gene of a glycerol-3-phosphate dehydrogenase and alleles plus derivatives of this gene together with the promoter sequence and other regulator elements. This means that they form complete transcription units.
Three genomic clones are characterized below. These include the ClGPDHg3 genomic clone with a 15.9 kb DNA insertion, the ClGPDHg5 genomic clone with a 17.7 kb DNA insertion, and the ClGPDHg9 genomic clone with a 15.6 kb DNA insertion. FIG. 3 shows a map of the DNA insertions of the genomic clones with various restriction enzymes. The black bars indicate the fragments that hybridize with a 5' probe of the GPDH20 cDNA. The white bars show the areas of DNA insertions that were sequenced and are included in the Sequence Listing.
Sequence analysis of the areas presented in FIG. 3 (white bars) of the three genomic clones ClGPDHg5, ClGPDHg3 and ClGPDHg9 has shown that they contain the complete or partial structure gene of GPDH with all or most of the promoter sequence (5' direction). FIG. 4 shows a schematic diagram of the sequenced areas of the genomic clones. The ClGPDHg5, ClGPDHg9 and ClGPDHg3 genomic clones contain the complete structure genes of GPDH in addition to promoter sequences. The entire promoter of GPDH was sequenced from the ClGPDHg9 genomic clone.
Thus a 4434 bp DNA fragment of the ClGPDHg5 genomic clone contains parts of the promoter and the complete structure gene of GPDH in the 5' area. The double-stranded-sequenced DNA sequence is SEQ ID NO:9. The amino acid sequence derived from it is shown as SEQ ID NO:10 in the Sequence Listing. The protein-coding sequence interrupted by DNA areas not translated (introns) with 372 amino acids begins with the ATG start codon in position 1394 and ends before the TAG stop codon in position 4005. The putative TATA box is located at positions 1332 to 1336. Transcription presumably starts at position 1364 (Joshi, NAR 15 (1987) pages 6643-6653). The polyA signal is located in positions 4205 to 4210 at the 3' end. Position 4221 corresponds to the last nucleotide before the polyA area of ClGPDH30 SEQ ID NO:7 cDNA (see position 1365in SEQ ID NO:7).
The complete structure gene of GPDH as well as parts of the promoter in 5' direction are contained in a 4006 bp DNA fragment from the ClGPDHg3 genomic clone. The DNA sequence of the DNA fragment that was sequenced mostly as a double strand from ClGPDHg3 is SEQ ID NO:11. The amino acid sequence derived from it is shown as SEQ ID NO:12 in the Sequence Listing. The protein coding area interrupted by intron sequences begins at position 1182 (see SEQ ID NO:11) with the ATG start codon and ends with the TAG stop codon at position 190 (see SEQ ID:12. CAAT box and TATA box signal sequences are located at positions 1055 to 1058 and 1103-1107 before the start of transcription. Assumed transcription starting points are at positions 1136 and 1148. Owing to a lack of sequence data, an area of approximately 480 base pairs is not identified within the coding sequence. The polyA signal is located in the untranslated 3' area at positions 393 to 398 (SEQ ID:12).
The entire promoter as well as the first exon of the sequence coding for GPDH are contained in a 1507 bp DNA fragment from the ClGPDHg9 genomic clone. The DNA sequence that was sequenced mostly as a double strand is SEQ ID NO:15. The amino acid sequence derived from it is shown as SEQ ID NO:16 in the Sequence Listing. The TATA box is located at positions 1108 to 1112 before the start of transcription. The protein coding sequence begins with the ATG start codon at position 1193 and ends at position 1376, where an untranslated area (intron) begins. Transcription presumably starts at position 1144.
By comparing DNA sequences, it has been found that ClGPDH30 SEQ ID NO:7 cDNA, which includes a complete protein reading frame for GPDH, is identical to the GPDH gene from the ClGPDHg5 SEQ ID NO:9 genomic clone. Consequently, the ClGPDHg5 SEQ ID NO:9 genomic clone can be classified in class A (see above). The ClGPDH132 SEQ ID NO:5 cDNA with an almost complete protein reading frame for GPDH is identical to the gene from the ClGPDHg9 SEQ ID NO:15 genomic clone, which consequently may be assigned to class B (see above). The gene from the ClGPDHg3 SEQ ID NO:13 genomic clone cannot be assigned to either of the two classes, and thus forms another class C.
Genetic engineering methods (in the form of anti-sense expression or overexpression) can be used to introduce or transfer the DNA sequences according to this invention that code for a glycerol-3-phosphate dehydrogenase into plants for the production of these dehydrogenases for the purpose of altering the biosynthesis yield of these plants. Inasmuch as the DNA sequences according to this invention are not a complete transcription unit, they are preferably introduced into the plants together with suitable promoters, especially in recombinant vectors, such as binary vectors. Genomic clones can be used as separate complete transcription units for the transformation of plants in order to influence the triacyiglyceride content and the fatty acid distribution.
Any species of plants can be transformed for this purpose. Oil-bearing plants, such as rapeseed, sunflower, linseed, oil palm and soybean are preferred for this transformation in order to influence the triacyrglyceride biosynthesis in these plants in the manner desired.
The introduction of DNA sequences according to this invention that code for a glycerol-3-phosphate dehydrogenase as well as the complete genes contained in the genomic clones of a glycerol-3-phosphate dehydrogenase by the methods of genetic engineering can be performed with the aid of conventional transformation techniques. Such techniques include direct gene transfer, such as microinjection, electroporation, use of particle gun, steeping plant parts in DNA solutions, pollen or pollen tube transformation, viral vector-mediated transfer and liposome-mediated transfer as well as the transfer of appropriate recombinant Ti plasmids or Ri plasmids through Agrobacterium tumefaciens and transformation by plant viruses.
The DNA sequences according to this invention as well as the complete genes of a glycerol-3-phosphate dehydragenase contained in the genomic clones are excellent for achieving a significant increase in oil production by transgeneic plants. This increase in oil yield is obtained with an increase in triacylglyceride content in the seed due to overexpression of GPDH. Furthermore, a reduction in glycerol-3-phosphate dehydrogenase can be obtained through anti-sense expression or cosuppression, so the building blocks for triacylglyceride synthesis are missing. This effect is especially beneficial when the production of wax esters (such as jojoba wax esters) in the seeds of tranisgeneic plants is to be improved. Another possible application of DNA sequences according to this invention as well as the genes from the genomic clones would be for suppressing triacylglyceride biosynthesis in transgeneic plants and making available the CoA ester as well as glycerol-3-phosphate for other biosyntheses.
Moreover, the promoters of glycerol-3-phosphate dehydrogenase genes from clones according to this invention can, for example, be used for targeted expression of chimeric genes in embryo-specific tissue. On the basis of experimental data it is assumed with regard to the specificity of the promoters that the promoters of genes from the ClGPDHg5 SEQ ID NO:9 and ClGPDHg9 SEQ ID NO:15 genomic clones are seed-specific, while the promoter of the gene from the ClGPDHg3 SEQ ID NO:11 genomic clone has little or no activity in the embryo. Thus, for example, a 1387 bp BamHI/AlwNI fragment of ClGPDHg5 SEQ ID NO:9 is suitable for transcriptional fusion, a 1189 base pair SphI/NarI fragment of ClGPDHg9 SEQ ID NO:15 is suitable for translational fusion and a 1172 base pair BamHI/BsmAI (part.) fragment of ClGPDHg3 SEQ ID NO:11 is suitable for transcriptional fusion. Larger (or smaller) promoter fragments can be used for expression of chimeric genes on the basis of additional clones present on the genetic clones. Likewise, any regulatory sequences located downstream from the first codon of the GPDH gene are obtained for targeted expression of chimeric genes from the cloned fragments of genomic DNA.
Northern Blot analysis with polyA + -RNA from various Cuphea lanceolata tissues with ClGPDH20 SEQ ID NO:1 cDNA as a probe shows very large amounts of RNA in embryos in comparison with other tissues (see FIG. 5). The increase in RNA correlates with increased gene expression and consequently indicates an extremely strong promoter.
The following examples are presented to illustrate this invention.
EXAMPLES
The plant material used in the context of the present invention was obtained from Cuphea lanceolata (Lythraceae) (small lanceolate tube flower).
Example 1
Production of Glycerol-3-phosphate Dehydroaenase cDNAs from Cuphea Lanceolata
A cDNA library was prepared from Cuphea lanceolata (wild type) took place with the help of the ZAP® cDNA synthesis kit according to the manufacturer's instructions (Stratagene, La Jolla, USA). Messenger RNA from isolated immature embryos about two to three weeks old was used as raw material for the synthesis of the cDNAs. The cDNA library obtained in this way contained 9.5×10 5 recombinant phages.
Functional complementation for isolation of cDNAs that code for a glycerol-3-phosphate dehydrogenase was performed with the E. Coli BB26-36 strain (R. M. Bell, J. Bact. 117 (1974) pages 1065-1076). The bacterial medium for culturing BB26-36 (bearing the plsB26 and plsX mutations) was supplemented with 0.1% glycerol to supplement the bacteria. A medium without glycerol was used for functional complementation.
The pBluescript plasmids were cut out of the above cDNA library in 1-ZAP II according to the manufacturer's instructions (Stratagene) by in vivo excision using helper phages and then packed in phage coats: 200 ml of XL1Blue E. Coli cells (OD 600 =1) were infected with 5×10 5 pfu of the 1-ZAP II cDNA library, and, in order to guarantee coinfection, were also infected with a tenfold amount of f1 R408 helper phages. After incubating for 15 minutes at a temperature of 37° C. for phage adsorption, 5 ml 2×YT medium were added and agitated for three hours more at a temperature of 37° C. During this time, the cells of the pBluescript plasmids packed in the coats of helper phages are secreting the so-called phagemids into the medium. The bacteria were killed and the 1 phages were inactivated by a heating for 20 minutes at 70° C. After centrifuging, the supernatant containing helper phages along with phagemids was removed. This supernatant was used for infection of the mutant BB26-36 strain.
Complementation was performed after infecting the E. coli BB26-36 strain with phagemids containing cDNA plasmids that code for a glycerol-3-phosphate dehydrogenase. M56-LP medium (Bell, loc. cit.) with 50 mg ampicillin was used for selection (without glycerol-3-phosphate). Retransformation of BB26-36 was performed by the method of D. Hanahan, J. Mol. Biol. 166 (1983) pages 557-580, with subsequent plating on the selective medium mentioned.
Delection clones for determining the sequence of the DNA fragments of positive cDNA clones were produced by means of exonuclease III (Strategene) and were sequenced according to the method of Sanger et al., Proc. Nat. Acad. Sci. 74 (1977) pages 5463-5467. Some of the DNA sequencing was performed radioactively with the help of the T7 Sequencing® Kit or with a Pharmacia Automated Laser Fluorescent A.L.F.® DNA sequencer. The sequences were analyzed with the help of computer software from the University of Wisconsin Genetics Computer Group (J. Devereux et al., Nucl. Acids Res. 12 (1984) pages 387-394).
Furthermore, cDNA clones were isolated by screening a cDNA library from Cuphea lanceolata with ClGPDH20 SEQ ID NO:1 cDNA as a probe. For this, a cDNA library from Cuphea lanceolata (wild type) was produced according to the manufacturer's instructions with the ZAP® cDNA Synthesis Kit. Messenger RNA from isolated, immature embryos about two to three weeks old was the raw material for synthesis of the cDNAs. The cDNA library obtained contained 9.6×10 5 recombinant phages with approx. 50% clones with more than 500 bp insertions. The cDNA library was examined with CLGPDH20 SEQ ID NO:1 as a probe, and 18 cDNAs were isolated and partially or completely sequenced in the usual manner. Of these cDNAs, 12 were class A, and 6 cDNAs were in class B.
The enzyme measurements were performed with the fusion protein according to the method of Santora et al., Arch. Biochem. Biophys. 196 (1979) pages 403-411.
Example 2
Production of Genomic Clones of Glycerol-3-phosphate Dehydrogenase from Cuphea lanceolata
Genomic DNA from young Cuphea lanceolata leaves were isolated for this example (S. L. Della Porta et al., Plant. Mol. Biol. Rep. 1, (1983) pages 19-21). The DNA was then partially cleaved with the restriction enzyme Sau3A, whereupon DNA fragments of 11,000 to 19,000 base pairs were cloned in vector 1FIXII (Stratagene) that was cleaved with XhoI after the respective interfaces were partially filled with two nucleotides in any given case. The genomic DNA library that was not reproduced amounted to 5.4 times the genome of Cuphea lanceolata. Thirty-one genomic clones were then isolated from this library with ClGPDH20-cDNA as a probe.
The three genomic clones ClGPDHg3 (15.9 kb DNA insertion), ClGPDHg5 (17.7 kb DNA insertion) and ClGPDHg9 (15.6 kb DNA insertion) were characterized in greater detail. Suitable subclones were produced in the usual manner and their insertions were sequenced with the ExoIII/Mung bean kit and also with oligonucleotide primers in order to bridge any gaps.
If any of the procedures customary in molecular biology have not have been described adequately here, such procedures were performed by standard methods as described in Sambrook et al., A Laboratory Manual, second edition (1989).
__________________________________________________________________________# SEQUENCE LISTING - - - - (1) GENERAL INFORMATION: - - (iii) NUMBER OF SEQUENCES: 17 - - - - (2) INFORMATION FOR SEQ ID NO:1: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 1354 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: cDNA to mRNA - - (iii) HYPOTHETICAL: NO - - (iv) ANTI-SENSE: NO - - (vi) ORIGINAL SOURCE: (A) ORGANISM: Cuphea la - #nceolata - - (vii) IMMEDIATE SOURCE: (A) LIBRARY: ZAP cDNA - #library (B) CLONE: C1GPDH20 - - (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: 17..1132 - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1: - - GAATTCGGCA CGAGCA ATG GCT CCC TCT GAG CTC AAC - #TGC ACC CAC CAG 49 - #Met Ala Pro Ser Glu Leu Asn Cys Thr His G - #ln - # 1 5 - # 10 - - AAC CAG CAT TCA AGC GGT TAC GAC GGA CCC AG - #A TCG AGG GTC ACC GTT 97 Asn Gln His Ser Ser Gly Tyr Asp Gly Pro Ar - #g Ser Arg Val Thr Val 15 - # 20 - # 25 - - GTC GGT AGT GGA AAC TGG GGT AGT GTT GCT GC - #C AAG CTC ATT GCT ACC145 Val Gly Ser Gly Asn Trp Gly Ser Val Ala Al - #a Lys Leu Ile Ala Thr 30 - # 35 - # 40 - - AAT ACC CTC AAG CTT CCA TCT TTT CAT GAT GA - #A GTG AGA ATG TGG GTA193 Asn Thr Leu Lys Leu Pro Ser Phe His Asp Gl - #u Val Arg Met Trp Val 45 - # 50 - # 55 - - TTT GAG GAG ACG CTA CCG AGC GGC GAG AAG CT - #T ACT GAT GTC ATC AAC241 Phe Glu Glu Thr Leu Pro Ser Gly Glu Lys Le - #u Thr Asp Val Ile Asn 60 - # 65 - # 70 - # 75 - - CAG ACC AAT GAA AAT GTT AAG TAT CTC CCC GG - #A ATT AAG CTC GGT AGG289 Gln Thr Asn Glu Asn Val Lys Tyr Leu Pro Gl - #y Ile Lys Leu Gly Arg 80 - # 85 - # 90 - - AAT GTT GTT GCA GAT CCA GAC CTC GAA AAC GC - #A GTT AAG GAT GCA AAT337 Asn Val Val Ala Asp Pro Asp Leu Glu Asn Al - #a Val Lys Asp Ala Asn 95 - # 100 - # 105 - - ATG CTC GTG TTT GTG ACA CCG CAT CAG TTC AT - #G GAG GGC ATC TGC AAA385 Met Leu Val Phe Val Thr Pro His Gln Phe Me - #t Glu Gly Ile Cys Lys 110 - # 115 - # 120 - - AGA CTC GAA GGG AAA ATA CAA GAA GGA GCA CA - #G GCT CTC TCC CTT ATA433 Arg Leu Glu Gly Lys Ile Gln Glu Gly Ala Gl - #n Ala Leu Ser Leu Ile125 - # 130 - # 135 - - AAG GGC ATG GAG GTC AAA ATG GAG GGG CCT TG - #C ATG ATC TCG AGC TTA481 Lys Gly Met Glu Val Lys Met Glu Gly Pro Cy - #s Met Ile Ser Ser Leu 140 1 - #45 1 - #50 1 -#55 - - ATC TCT GAT CTT CTC GGG ATT AAC TGC TGT GT - #C CTA ATG GGG GCAAAC 529 Ile Ser Asp Leu Leu Gly Ile Asn Cys Cys Va - #l Leu Met Gly Ala Asn 160 - # 165 - # 170 - - ATC GCT AAT GAG ATT GCT GTT GAG AAA TTC AG - #T GAA GCG ACA GTC GGG577 Ile Ala Asn Glu Ile Ala Val Glu Lys Phe Se - #r Glu Ala Thr Val Gly 175 - # 180 - # 185 - - TTC AGA GAA AAT AGA GAT ATT GCA GAG AAA TG - #G GTT CAG CTC TTT AGC625 Phe Arg Glu Asn Arg Asp Ile Ala Glu Lys Tr - #p Val Gln Leu Phe Ser 190 - # 195 - # 200 - - ACT CCG TAC TTC ATG GTC TCA GCT GTT GAA GA - #T GTT GAA GGA GTA GAA673 Thr Pro Tyr Phe Met Val Ser Ala Val Glu As - #p Val Glu Gly Val Glu205 - # 210 - # 215 - - CTT TGT GGA ACA CTG AAG AAT ATC GTG GCC AT - #A GCA GCC GGT TTT GTG721 Leu Cys Gly Thr Leu Lys Asn Ile Val Ala Il - #e Ala Ala Gly Phe Val 220 2 - #25 2 - #30 2 -#35 - - GAT GGA TTG GAG ATG GGA AAC AAC ACA AAA GC - #A GCA ATT ATG AGGATC 769 Asp Gly Leu Glu Met Gly Asn Asn Thr Lys Al - #a Ala Ile Met Arg Ile 240 - # 245 - # 250 - - GGG TTA CGG GAG ATG AAG GCA TTC TCC AAG CT - #T TTG TTT CCA TCT GTT817 Gly Leu Arg Glu Met Lys Ala Phe Ser Lys Le - #u Leu Phe Pro Ser Val 255 - # 260 - # 265 - - AAG GAC ACT ACT TTC TTC GAG AGC TGT GGA GT - #C GCT GAC CTC ATC ACA865 Lys Asp Thr Thr Phe Phe Glu Ser Cys Gly Va - #l Ala Asp Leu Ile Thr 270 - # 275 - # 280 - - ACT TGT TTG GGC GGG AGA AAC AGA AAA GTT GC - #T GAG GCT TTT GCA AAG913 Thr Cys Leu Gly Gly Arg Asn Arg Lys Val Al - #a Glu Ala Phe Ala Lys285 - # 290 - # 295 - - AAT GGC GGG AAA AGG TCA TTC GAT GAT CTC GA - #A GCA GAG ATG CTC CGG961 Asn Gly Gly Lys Arg Ser Phe Asp Asp Leu Gl - #u Ala Glu Met Leu Arg 300 3 - #05 3 - #10 3 -#15 - - GGG CAA AAA TTA CAG GGT GTC TCA ACA GCA AA - #G GAG GTC TAT GAAGTC 1009 Gly Gln Lys Leu Gln Gly Val Ser Thr Ala Ly - #s Glu Val Tyr Glu Val 320 - # 325 - # 330 - - TTG GGG CAC CGA GGC TGG CTC GAG CTG TTC CC - #G CTC TTC TCA ACC GTG 1057 Leu Gly His Arg Gly Trp Leu Glu Leu Phe Pr - #o Leu Phe Ser Thr Val 335 - # 340 - # 345 - - CAC GAG ATA TCC ACT GGC CGT CTG CCT CCT TC - #A GCC ATC GTC GAA TAC 1105 His Glu Ile Ser Thr Gly Arg Leu Pro Pro Se - #r Ala Ile Val Glu Tyr 350 - # 355 - # 360 - - AGC GAA CAA AAA ACC ATC TTC TCT TGG TAGAGCAAG - #A GGCTGCCCTT 1152 Ser Glu Gln Lys Thr Ile Phe Ser Trp365 - # 370 - - GAAAGACTAA GAGCCACCCT GCCCTGTTTA AAGGGCTAAA AGTTTAATAT TT -#CTCTGCAG 1212 - - CCTAAACAGT CGGAAACATT GAAAATCTAG GATGTATAAG AAAAAAAAAA GA -#AGGTTTGA 1272 - - AGGAAGTATG GATGGGCATG AATGTATTTA TTTTCGGTAT ACTCTTTTTC TG -#CAAAAATA 1332 - - ATTTCTTCAG AAAGGGGGGC CC - # - # 1354 - - - - (2) INFORMATION FOR SEQ ID NO:2: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 372 amino - #acids (B) TYPE: amino acid (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: protein - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2: - - Met Ala Pro Ser Glu Leu Asn Cys Thr His Gl - #n Asn Gln His Ser Ser 1 5 - # 10 - # 15 - - Gly Tyr Asp Gly Pro Arg Ser Arg Val Thr Va - #l Val Gly Ser Gly Asn 20 - # 25 - # 30 - - Trp Gly Ser Val Ala Ala Lys Leu Ile Ala Th - #r Asn Thr Leu Lys Leu 35 - # 40 - # 45 - - Pro Ser Phe His Asp Glu Val Arg Met Trp Va - #l Phe Glu Glu Thr Leu 50 - # 55 - # 60 - - Pro Ser Gly Glu Lys Leu Thr Asp Val Ile As - #n Gln Thr Asn Glu Asn 65 - # 70 - # 75 - # 80 - - Val Lys Tyr Leu Pro Gly Ile Lys Leu Gly Ar - #g Asn Val Val Ala Asp 85 - # 90 - # 95 - - Pro Asp Leu Glu Asn Ala Val Lys Asp Ala As - #n Met Leu Val Phe Val 100 - # 105 - # 110 - - Thr Pro His Gln Phe Met Glu Gly Ile Cys Ly - #s Arg Leu Glu Gly Lys 115 - # 120 - # 125 - - Ile Gln Glu Gly Ala Gln Ala Leu Ser Leu Il - #e Lys Gly Met Glu Val130 - # 135 - # 140 - - Lys Met Glu Gly Pro Cys Met Ile Ser Ser Le - #u Ile Ser Asp Leu Leu 145 1 - #50 1 - #55 1 -#60 - - Gly Ile Asn Cys Cys Val Leu Met Gly Ala As - #n Ile Ala Asn GluIle 165 - # 170 - # 175 - - Ala Val Glu Lys Phe Ser Glu Ala Thr Val Gl - #y Phe Arg Glu Asn Arg 180 - # 185 - # 190 - - Asp Ile Ala Glu Lys Trp Val Gln Leu Phe Se - #r Thr Pro Tyr Phe Met 195 - # 200 - # 205 - - Val Ser Ala Val Glu Asp Val Glu Gly Val Gl - #u Leu Cys Gly Thr Leu210 - # 215 - # 220 - - Lys Asn Ile Val Ala Ile Ala Ala Gly Phe Va - #l Asp Gly Leu Glu Met 225 2 - #30 2 - #35 2 -#40 - - Gly Asn Asn Thr Lys Ala Ala Ile Met Arg Il - #e Gly Leu Arg GluMet 245 - # 250 - # 255 - - Lys Ala Phe Ser Lys Leu Leu Phe Pro Ser Va - #l Lys Asp Thr Thr Phe 260 - # 265 - # 270 - - Phe Glu Ser Cys Gly Val Ala Asp Leu Ile Th - #r Thr Cys Leu Gly Gly 275 - # 280 - # 285 - - Arg Asn Arg Lys Val Ala Glu Ala Phe Ala Ly - #s Asn Gly Gly Lys Arg290 - # 295 - # 300 - - Ser Phe Asp Asp Leu Glu Ala Glu Met Leu Ar - #g Gly Gln Lys Leu Gln 305 3 - #10 3 - #15 3 -#20 - - Gly Val Ser Thr Ala Lys Glu Val Tyr Glu Va - #l Leu Gly His ArgGly 325 - # 330 - # 335 - - Trp Leu Glu Leu Phe Pro Leu Phe Ser Thr Va - #l His Glu Ile Ser Thr 340 - # 345 - # 350 - - Gly Arg Leu Pro Pro Ser Ala Ile Val Glu Ty - #r Ser Glu Gln Lys Thr 355 - # 360 - # 365 - - Ile Phe Ser Trp370 - - - - (2) INFORMATION FOR SEQ ID NO:3: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 1464 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: cDNA to mRNA - - (iii) HYPOTHETICAL: NO - - (iv) ANTI-SENSE: NO - - (vi) ORIGINAL SOURCE: (A) ORGANISM: Cuphea la - #nceolata - - (vii) IMMEDIATE SOURCE: (A) LIBRARY: ZAP cDNA - #library (B) CLONE: C1GPDH109 - - (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: 45..1187 - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3: - - GAATTCGGCA CGAGCTTCCT CTGTTCTTCC TCTCTGCCTC TGCA ATG G - #CG CCTGCC 56 - # - # Met Ala Pro -#Ala - # - # 1 - - TTC GAA CCC CAT CAG CTG GCT CCC TCT GAG CT - #T AAC TCT GCC CACCAG 104 Phe Glu Pro His Gln Leu Ala Pro Ser Glu Le - #u Asn Ser Ala His Gln 5 - # 10 - # 15 - # 20 - - AAC CCA CAT TCA GGC GGA TAT GAC GGA CCC AG - #A TCG AGG GTC ACT GTC152 Asn Pro His Ser Gly Gly Tyr Asp Gly Pro Ar - #g Ser Arg Val Thr Val 25 - # 30 - # 35 - - GTC GGC AGC GGC AAC TGG GGC AGC GTC GCT GC - #C AAG CTC ATT GCT TCC200 Val Gly Ser Gly Asn Trp Gly Ser Val Ala Al - #a Lys Leu Ile Ala Ser 40 - # 45 - # 50 - - AAC ACC CTC AAG CTC CCA TCT TTC CAT GAT GA - #A GTG AGG ATG TGG GTA248 Asn Thr Leu Lys Leu Pro Ser Phe His Asp Gl - #u Val Arg Met Trp Val 55 - # 60 - # 65 - - TTT GAG GAG ACT CTA CCG GGC GGC GAG AAG CT - #C ACT GAT ATC ATC AAC296 Phe Glu Glu Thr Leu Pro Gly Gly Glu Lys Le - #u Thr Asp Ile Ile Asn 70 - # 75 - # 80 - - CAG ACC AAT GAA AAT GTT AAA TAT CTT CCC GG - #A ATT AAG CTC GGT GGG344 Gln Thr Asn Glu Asn Val Lys Tyr Leu Pro Gl - #y Ile Lys Leu Gly Gly 85 - # 90 - # 95 - #100 - - AAT GTT GTT GCT GAT CCA GAC CTC GAA AAT GC - #A GTT AAG GAT GCA AAT392 Asn Val Val Ala Asp Pro Asp Leu Glu Asn Al - #a Val Lys Asp Ala Asn 105 - # 110 - # 115 - - ATG CTC GTG TTT GTC ACA CCG CAT CAG TTC AT - #G GAG GGC ATC TGC AAA440 Met Leu Val Phe Val Thr Pro His Gln Phe Me - #t Glu Gly Ile Cys Lys 120 - # 125 - # 130 - - AGA CTT GTC GGG AAG ATA CAG GAA GGA GCG CA - #G GCT CTC TCC CTT ATA488 Arg Leu Val Gly Lys Ile Gln Glu Gly Ala Gl - #n Ala Leu Ser Leu Ile 135 - # 140 - # 145 - - AAA GGC ATG GAG GTC AAG ATG GAG GGG CCT TG - #C ATG ATC TCG AGC CTA536 Lys Gly Met Glu Val Lys Met Glu Gly Pro Cy - #s Met Ile Ser Ser Leu150 - # 155 - # 160 - - ATC TCA GAT CTT CTC GGG ATC AAC TGC TGT GT - #C CTT AAT GGG GCA AAC584 Ile Ser Asp Leu Leu Gly Ile Asn Cys Cys Va - #l Leu Asn Gly Ala Asn 165 1 - #70 1 - #75 1 -#80 - - ATC GCT AAT GAG ATT GCT GTT GAG AAA TTC AG - #T GAA GCG ACT GTCGGG 632 Ile Ala Asn Glu Ile Ala Val Glu Lys Phe Se - #r Glu Ala Thr Val Gly 185 - # 190 - # 195 - - TTC AGA GAA AAT AGA GAT ATT GCG GAA AAA TG - #G GTT CAG CTC TTT AGC680 Phe Arg Glu Asn Arg Asp Ile Ala Glu Lys Tr - #p Val Gln Leu Phe Ser 200 - # 205 - # 210 - - ACT CCA TAC TTC ATG GTC TCA GCT GTT GAA GA - #T GTT GAA GGA GTA GAG728 Thr Pro Tyr Phe Met Val Ser Ala Val Glu As - #p Val Glu Gly Val Glu 215 - # 220 - # 225 - - CTT TGT GGA ACA CTG AAG AAT ATT GTG GCC AT - #A GCA GCG GGT TTT GTT776 Leu Cys Gly Thr Leu Lys Asn Ile Val Ala Il - #e Ala Ala Gly Phe Val230 - # 235 - # 240 - - GAT GGA TTG GAG ATG GGA AAC AAC ACA AAA GC - #G GCA ATT ATG AGG ATC824 Asp Gly Leu Glu Met Gly Asn Asn Thr Lys Al - #a Ala Ile Met Arg Ile 245 2 - #50 2 - #55 2 -#60 - - GGG CTG CGG GAG ATG AAA GCG TTC TCC AAG CT - #T TTG TTT CCA TCTGTT 872 Gly Leu Arg Glu Met Lys Ala Phe Ser Lys Le - #u Leu Phe Pro Ser Val 265 - # 270 - # 275 - - AAG GAC ACT ACT TTT TTC GAG AGC TGC GGA GT - #C GCT GAT CTC ATC ACA920 Lys Asp Thr Thr Phe Phe Glu Ser Cys Gly Va - #l Ala Asp Leu Ile Thr 280 - # 285 - # 290 - - ACT TGT TTG GGC GGA AGA AAC AGA AAA GTC GC - #T GAG GCT TTT GCA AAG968 Thr Cys Leu Gly Gly Arg Asn Arg Lys Val Al - #a Glu Ala Phe Ala Lys 295 - # 300 - # 305 - - AAT GGC GGA AAC AGG TCA TTT GAT GAT CTC GA - #A GCA GAG ATG CTC CGG 1016 Asn Gly Gly Asn Arg Ser Phe Asp Asp Leu Gl - #u Ala Glu Met Leu Arg310 - # 315 - # 320 - - GGG CAA AAA TTA CAG GGT GTC TCG ACA GCG AA - #A GAG GTC TAC GAG GTC 1064 Gly Gln Lys Leu Gln Gly Val Ser Thr Ala Ly - #s Glu Val Tyr Glu Val 325 3 - #30 3 - #35 3 -#40 - - CTG AGG CAC CGA GGC TGG CTC GAG TTG TTC CC - #G CTC TTC TCA ACCGTG 1112 Leu Arg His Arg Gly Trp Leu Glu Leu Phe Pr - #o Leu Phe Ser Thr Val 345 - # 350 - # 355 - - CAT GAG ATC TCC AGT GGC CGT CTG CCT CCT TC - #A GCC ATT GTT GAA TAC 1160 His Glu Ile Ser Ser Gly Arg Leu Pro Pro Se - #r Ala Ile Val Glu Tyr 360 - # 365 - # 370 - - AGC GAA CAA AAG CCT ACC TTC TCT TGG TAGAGAAAG - #A AACCAGGAAG 1207 Ser Glu Gln Lys Pro Thr Phe Ser Trp 375 - # 380 - - AACGGCGAGC CACTGTCCCC CGTTTAAAGG TTTACTATTT CTCTCTGCAC TT -#TGCAGCCT 1267 - - GAAGAGTCGG AAACATAGAA AATCTAGGAA GTTTCAGAAA AAGGAAGGTT TG -#GAGGATGT 1327 - - ATGGATGATA TATATACTAG GTGGGTATGA AGAGGAAGTT ATTACTATGA TG -#TTGGTATG 1387 - - TGGTAATGGC TAAGTACATG AGATCAAATA AATAGACAGA CCTTGGTTTC TT -#CTTTCTAA 1447 - - AAAAAAAGGG GGGGCCC - # - # - # 1464 - - - - (2) INFORMATION FOR SEQ ID NO:4: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 381 amino - #acids (B) TYPE: amino acid (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: protein - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4: - - Met Ala Pro Ala Phe Glu Pro His Gln Leu Al - #a Pro Ser Glu Leu Asn 1 5 - # 10 - # 15 - - Ser Ala His Gln Asn Pro His Ser Gly Gly Ty - #r Asp Gly Pro Arg Ser 20 - # 25 - # 30 - - Arg Val Thr Val Val Gly Ser Gly Asn Trp Gl - #y Ser Val Ala Ala Lys 35 - # 40 - # 45 - - Leu Ile Ala Ser Asn Thr Leu Lys Leu Pro Se - #r Phe His Asp Glu Val 50 - # 55 - # 60 - - Arg Met Trp Val Phe Glu Glu Thr Leu Pro Gl - #y Gly Glu Lys Leu Thr 65 - # 70 - # 75 - # 80 - - Asp Ile Ile Asn Gln Thr Asn Glu Asn Val Ly - #s Tyr Leu Pro Gly Ile 85 - # 90 - # 95 - - Lys Leu Gly Gly Asn Val Val Ala Asp Pro As - #p Leu Glu Asn Ala Val 100 - # 105 - # 110 - - Lys Asp Ala Asn Met Leu Val Phe Val Thr Pr - #o His Gln Phe Met Glu 115 - # 120 - # 125 - - Gly Ile Cys Lys Arg Leu Val Gly Lys Ile Gl - #n Glu Gly Ala Gln Ala130 - # 135 - # 140 - - Leu Ser Leu Ile Lys Gly Met Glu Val Lys Me - #t Glu Gly Pro Cys Met 145 1 - #50 1 - #55 1 -#60 - - Ile Ser Ser Leu Ile Ser Asp Leu Leu Gly Il - #e Asn Cys Cys ValLeu 165 - # 170 - # 175 - - Asn Gly Ala Asn Ile Ala Asn Glu Ile Ala Va - #l Glu Lys Phe Ser Glu 180 - # 185 - # 190 - - Ala Thr Val Gly Phe Arg Glu Asn Arg Asp Il - #e Ala Glu Lys Trp Val 195 - # 200 - # 205 - - Gln Leu Phe Ser Thr Pro Tyr Phe Met Val Se - #r Ala Val Glu Asp Val210 - # 215 - # 220 - - Glu Gly Val Glu Leu Cys Gly Thr Leu Lys As - #n Ile Val Ala Ile Ala 225 2 - #30 2 - #35 2 -#40 - - Ala Gly Phe Val Asp Gly Leu Glu Met Gly As - #n Asn Thr Lys AlaAla 245 - # 250 - # 255 - - Ile Met Arg Ile Gly Leu Arg Glu Met Lys Al - #a Phe Ser Lys Leu Leu 260 - # 265 - # 270 - - Phe Pro Ser Val Lys Asp Thr Thr Phe Phe Gl - #u Ser Cys Gly Val Ala 275 - # 280 - # 285 - - Asp Leu Ile Thr Thr Cys Leu Gly Gly Arg As - #n Arg Lys Val Ala Glu290 - # 295 - # 300 - - Ala Phe Ala Lys Asn Gly Gly Asn Arg Ser Ph - #e Asp Asp Leu Glu Ala 305 3 - #10 3 - #15 3 -#20 - - Glu Met Leu Arg Gly Gln Lys Leu Gln Gly Va - #l Ser Thr Ala LysGlu 325 - # 330 - # 335 - - Val Tyr Glu Val Leu Arg His Arg Gly Trp Le - #u Glu Leu Phe Pro Leu 340 - # 345 - # 350 - - Phe Ser Thr Val His Glu Ile Ser Ser Gly Ar - #g Leu Pro Pro Ser Ala 355 - # 360 - # 365 - - Ile Val Glu Tyr Ser Glu Gln Lys Pro Thr Ph - #e Ser Trp370 - # 375 - # 380 - - - - (2) INFORMATION FOR SEQ ID NO:5: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 1490 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: cDNA to mRNA - - (iii) HYPOTHETICAL: NO - - (iv) ANTI-SENSE: NO - - (vi) ORIGINAL SOURCE: (A) ORGANISM: Cuphea la - #nceolata - - (vii) IMMEDIATE SOURCE: (A) LIBRARY: ZAP cDNA - #library (B) CLONE: C1GPDH132 - - (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: 15..1115 - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:5: - - GAATTCGGCA CGAG CTT AAC TCT GCC CAC CAG AAC C - #CA CAT TCC AGC GGA 50 Leu A - #sn Ser Ala His Gln Asn Pro His Ser Ser Gl - #y - #1 5 - # 10 - - TAT GAA GGA CCC AGA TCG AGG GTC ACC GTC GT - #T GGC AGC GGC AAC TGG 98 Tyr Glu Gly Pro Arg Ser Arg Val Thr Val Va - #l Gly Ser Gly Asn Trp 15 - # 20 - # 25 - - GGC AGC GTC GCT GCC AAG CTC ATT GCT TCC AA - #C ACC CTC AAG CTC CCA146 Gly Ser Val Ala Ala Lys Leu Ile Ala Ser As - #n Thr Leu Lys Leu Pro 30 - # 35 - # 40 - - TCT TTC CAT GAT GAA GTG AGG ATG TGG GTA TT - #T GAG GAG ACT CTA CCG194 Ser Phe His Asp Glu Val Arg Met Trp Val Ph - #e Glu Glu Thr Leu Pro 45 - # 50 - # 55 - # 60 - - GGC GGC GAG AAG CTC ACT GAT ATC ATC AAC CA - #G ACC AAT GAA AAT GTT242 Gly Gly Glu Lys Leu Thr Asp Ile Ile Asn Gl - #n Thr Asn Glu Asn Val 65 - # 70 - # 75 - - AAA TAT CTT CCC GGA ATT AAG CTC GGT AGG AA - #T GTT GTT GCA GAT CCA290 Lys Tyr Leu Pro Gly Ile Lys Leu Gly Arg As - #n Val Val Ala Asp Pro 80 - # 85 - # 90 - - GAC CTC GAA AAC GCA GTT AAG GAT GCA AAT AT - #G CTC GTT TTC GTC ACA338 Asp Leu Glu Asn Ala Val Lys Asp Ala Asn Me - #t Leu Val Phe Val Thr 95 - # 100 - # 105 - - CCG CAT CAG TTC GTG GAG GGC ATC TGC AAA AG - #A CTT GTA GGG AAG ATA386 Pro His Gln Phe Val Glu Gly Ile Cys Lys Ar - #g Leu Val Gly Lys Ile110 - # 115 - # 120 - - CAG GAA GGA GCG CAG GCT CTC TCT CTT ATA AA - #A GGC ATG GAG GTC AAA434 Gln Glu Gly Ala Gln Ala Leu Ser Leu Ile Ly - #s Gly Met Glu Val Lys 125 1 - #30 1 - #35 1 -#40 - - ATG GAG GGG CCT TGC ATG ATC TCG AGC CTA AT - #C TCA GAT CTT CTCGGG 482 Met Glu Gly Pro Cys Met Ile Ser Ser Leu Il - #e Ser Asp Leu Leu Gly 145 - # 150 - # 155 - - ATC AAT TGC TGT GTC CTT AAT GGG GCG AAC AT - #C GCT AAT GAG ATT GCT530 Ile Asn Cys Cys Val Leu Asn Gly Ala Asn Il - #e Ala Asn Glu Ile Ala 160 - # 165 - # 170 - - GTT GAG AAA TTC AGT GAA GCG ACT GTC GGG TT - #C AGA GAA AAT AGA GAT578 Val Glu Lys Phe Ser Glu Ala Thr Val Gly Ph - #e Arg Glu Asn Arg Asp 175 - # 180 - # 185 - - ATT GCG GAA AAA TGG GTT CAG CTC TTT AGC AC - #T CCA TAC TTC ATG GTC626 Ile Ala Glu Lys Trp Val Gln Leu Phe Ser Th - #r Pro Tyr Phe Met Val190 - # 195 - # 200 - - TCA GCT GTT GAA GAT GTT GAA GGA GTA GAG CT - #T TGT GGA ACA CTG AAG674 Ser Ala Val Glu Asp Val Glu Gly Val Glu Le - #u Cys Gly Thr Leu Lys 205 2 - #10 2 - #15 2 -#20 - - AAT ATT GTG GCC ATA GCA GCG GGT TTT GTG GA - #T GGA CTG GAG ATGGGA 722 Asn Ile Val Ala Ile Ala Ala Gly Phe Val As - #p Gly Leu Glu Met Gly 225 - # 230 - # 235 - - AAC AAC ACA AAA GCA GCA ATT ATG AGG ATC GG - #G CTG CGG GAG ATG AAA770 Asn Asn Thr Lys Ala Ala Ile Met Arg Ile Gl - #y Leu Arg Glu Met Lys 240 - # 245 - # 250 - - GCG TTC TCC AAG CTT TTG TTT CCA TCT GTT AA - #G GAC ACT ACT TTT TTC818 Ala Phe Ser Lys Leu Leu Phe Pro Ser Val Ly - #s Asp Thr Thr Phe Phe 255 - # 260 - # 265 - - GAG AGC TGC GGA GTC GCT GAT CTC ATC ACA AC - #T TGT TTG GGC GGA AGA866 Glu Ser Cys Gly Val Ala Asp Leu Ile Thr Th - #r Cys Leu Gly Gly Arg270 - # 275 - # 280 - - AAC AGA AAA GTC GCT GAG GCT TTT GCA AAG AA - #T GGC GGT AAC AGG TCA914 Asn Arg Lys Val Ala Glu Ala Phe Ala Lys As - #n Gly Gly Asn Arg Ser 285 2 - #90 2 - #95 3 -#00 - - TTC GAT GAT CTC GAA GCA GAG ATG CTC CGG GG - #G CAA AAA TTA CAGGGT 962 Phe Asp Asp Leu Glu Ala Glu Met Leu Arg Gl - #y Gln Lys Leu Gln Gly 305 - # 310 - # 315 - - GTC TCG ACA GCG AAA GAG GTC TAC GAG GTC CT - #G AGG CAC CGA GGT TGG 1010 Val Ser Thr Ala Lys Glu Val Tyr Glu Val Le - #u Arg His Arg Gly Trp 320 - # 325 - # 330 - - CTC GAG TTG TTC CCG CTC TTC TCA ACC GTG CA - #T GAG ATC TCC ACT GGC 1058 Leu Glu Leu Phe Pro Leu Phe Ser Thr Val Hi - #s Glu Ile Ser Thr Gly 335 - # 340 - # 345 - - CGT CTG CCT CCT TCA GCC ATT GTT GAA TAC AG - #C GAA CAA AAG CCC ACC 1106 Arg Leu Pro Pro Ser Ala Ile Val Glu Tyr Se - #r Glu Gln Lys Pro Thr350 - # 355 - # 360 - - TTC TCT TGG TAGAGAAAGA AGCAACCAGG AAGAACGGCG AGCCACTCT - #G 1155 Phe Ser Trp 365 - - CCTCGTTTAA AGGGTTACTA TTTCTCTACA CTCTGCAGCC TGAAGAGTCG GA -#AACATCGA 1215 - - AAATCTAGGA AGTCTCAGAA AAATGAAGGT TTGGAGGATG TATGGATGAT AT -#ATATACTA 1275 - - GGTGGGTATG AAGAGGAAGT TATTACTATG ATGTTGGTAT GTGGTAATGG CT -#AAGTACAT 1335 - - GAGATCAAAT AAATAGACAG ACCTTGGTTT CTTCTATCTC GATTCGGTCT CG -#TCGAGTTT 1395 - - GGCGAAACTC AACTGAACTT CCTGAGTACC CTGCTACCTA TTACATGTAA TG -#TTCCTATT 1455 - - TATATGCTTA AAAAAAAAAA AAAAAAAAAC TCGAG - #- # 1490 - - - - (2) INFORMATION FOR SEQ ID NO:6: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 367 amino - #acids (B) TYPE: amino acid (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: protein - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:6: - - Leu Asn Ser Ala His Gln Asn Pro His Ser Se - #r Gly Tyr Glu GlyPro 1 5 - # 10 - # 15 - - Arg Ser Arg Val Thr Val Val Gly Ser Gly As - #n Trp Gly Ser Val Ala 20 - # 25 - # 30 - - Ala Lys Leu Ile Ala Ser Asn Thr Leu Lys Le - #u Pro Ser Phe His Asp 35 - # 40 - # 45 - - Glu Val Arg Met Trp Val Phe Glu Glu Thr Le - #u Pro Gly Gly Glu Lys 50 - # 55 - # 60 - - Leu Thr Asp Ile Ile Asn Gln Thr Asn Glu As - #n Val Lys Tyr Leu Pro 65 - # 70 - # 75 - # 80 - - Gly Ile Lys Leu Gly Arg Asn Val Val Ala As - #p Pro Asp Leu Glu Asn 85 - # 90 - # 95 - - Ala Val Lys Asp Ala Asn Met Leu Val Phe Va - #l Thr Pro His Gln Phe 100 - # 105 - # 110 - - Val Glu Gly Ile Cys Lys Arg Leu Val Gly Ly - #s Ile Gln Glu Gly Ala 115 - # 120 - # 125 - - Gln Ala Leu Ser Leu Ile Lys Gly Met Glu Va - #l Lys Met Glu Gly Pro130 - # 135 - # 140 - - Cys Met Ile Ser Ser Leu Ile Ser Asp Leu Le - #u Gly Ile Asn Cys Cys 145 1 - #50 1 - #55 1 -#60 - - Val Leu Asn Gly Ala Asn Ile Ala Asn Glu Il - #e Ala Val Glu LysPhe 165 - # 170 - # 175 - - Ser Glu Ala Thr Val Gly Phe Arg Glu Asn Ar - #g Asp Ile Ala Glu Lys 180 - # 185 - # 190 - - Trp Val Gln Leu Phe Ser Thr Pro Tyr Phe Me - #t Val Ser Ala Val Glu 195 - # 200 - # 205 - - Asp Val Glu Gly Val Glu Leu Cys Gly Thr Le - #u Lys Asn Ile Val Ala210 - # 215 - # 220 - - Ile Ala Ala Gly Phe Val Asp Gly Leu Glu Me - #t Gly Asn Asn Thr Lys 225 2 - #30 2 - #35 2 -#40 - - Ala Ala Ile Met Arg Ile Gly Leu Arg Glu Me - #t Lys Ala Phe SerLys 245 - # 250 - # 255 - - Leu Leu Phe Pro Ser Val Lys Asp Thr Thr Ph - #e Phe Glu Ser Cys Gly 260 - # 265 - # 270 - - Val Ala Asp Leu Ile Thr Thr Cys Leu Gly Gl - #y Arg Asn Arg Lys Val 275 - # 280 - # 285 - - Ala Glu Ala Phe Ala Lys Asn Gly Gly Asn Ar - #g Ser Phe Asp Asp Leu290 - # 295 - # 300 - - Glu Ala Glu Met Leu Arg Gly Gln Lys Leu Gl - #n Gly Val Ser Thr Ala 305 3 - #10 3 - #15 3 -#20 - - Lys Glu Val Tyr Glu Val Leu Arg His Arg Gl - #y Trp Leu Glu LeuPhe 325 - # 330 - # 335 - - Pro Leu Phe Ser Thr Val His Glu Ile Ser Th - #r Gly Arg Leu Pro Pro 340 - # 345 - # 350 - - Ser Ala Ile Val Glu Tyr Ser Glu Gln Lys Pr - #o Thr Phe Ser Trp 355 - # 360 - # 365 - - - - (2) INFORMATION FOR SEQ ID NO:7: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 1390 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: cDNA to mRNA - - (iii) HYPOTHETICAL: NO - - (iv) ANTI-SENSE: NO - - (vi) ORIGINAL SOURCE: (A) ORGANISM: Cuphea la - #nceolata - - (vii) IMMEDIATE SOURCE: (A) LIBRARY: ZAP cDNA - #library (B) CLONE: C1GPDH30 - - (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: 34..1149 - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:7: - - GAATTCGGCA CGAGTTTCTT CTCAGCCTCT GCA ATG GCT CCC TC - #T GAG CTCAAC 54 - # - # Met Ala Pro Ser Glu Leu Asn - # - # 1 - #5 - - TGC ACC CAC CAG AAC CCA CAT TCA AGC GGT TA - #C GAC GGA CCC AGA TCG102 Cys Thr His Gln Asn Pro His Ser Ser Gly Ty - #r Asp Gly Pro Arg Ser 10 - # 15 - # 20 - - AGG GTC ACC GTT GTC GGT AGT GGA AAC TGG GG - #C AGT GTC GCT GCC AAG150 Arg Val Thr Val Val Gly Ser Gly Asn Trp Gl - #y Ser Val Ala Ala Lys 25 - # 30 - # 35 - - CTC ATT GCT TCC AAT ACC CTC AAG CTT CCA TC - #T TTT CAT GAT GAA GTG198 Leu Ile Ala Ser Asn Thr Leu Lys Leu Pro Se - #r Phe His Asp Glu Val 40 - # 45 - # 50 - # 55 - - AGA ATG TGG GTA TTT GAG GAG ACT CTA CCG AG - #C GGC GAG AAG CTT ACT246 Arg Met Trp Val Phe Glu Glu Thr Leu Pro Se - #r Gly Glu Lys Leu Thr 60 - # 65 - # 70 - - GAT GTC ATC AAC CAG ACC AAT GAA AAT GTT AA - #G TAT CTC CCC GGA ATT294 Asp Val Ile Asn Gln Thr Asn Glu Asn Val Ly - #s Tyr Leu Pro Gly Ile 75 - # 80 - # 85 - - AAG CTC GGT AGG AAT GTT GTT GCA GAT CCA GA - #C CTC GAA AAC GCA GTT342 Lys Leu Gly Arg Asn Val Val Ala Asp Pro As - #p Leu Glu Asn Ala Val 90 - # 95 - # 100 - - AAG GAT GCA AAT ATG CTC GTG TTT GTG ACA CC - #G CAT CAG TTC ATG GAG390 Lys Asp Ala Asn Met Leu Val Phe Val Thr Pr - #o His Gln Phe Met Glu105 - # 110 - # 115 - - GGC ATC TGC AAA AGA CTC GTA GGG AAA ATA CA - #G GAA GGA GCA CAG GCT438 Gly Ile Cys Lys Arg Leu Val Gly Lys Ile Gl - #n Glu Gly Ala Gln Ala 120 1 - #25 1 - #30 1 -#35 - - CTC TCC CTT ATA AAG GGC ATG GAG GTC AAA AT - #G GAG GGG CCT TGCATG 486 Leu Ser Leu Ile Lys Gly Met Glu Val Lys Me - #t Glu Gly Pro Cys Met 140 - # 145 - # 150 - - ATC TCG AGC CTA ATC TCT GAT CTT CTC GGG AT - #C AAC TGC TGT GTC CTA534 Ile Ser Ser Leu Ile Ser Asp Leu Leu Gly Il - #e Asn Cys Cys Val Leu 155 - # 160 - # 165 - - ATG GGG GCA AAC ATC GCT AAT GAG ATT GCT GT - #T GAG AAA TTC AGT GAA582 Met Gly Ala Asn Ile Ala Asn Glu Ile Ala Va - #l Glu Lys Phe Ser Glu 170 - # 175 - # 180 - - GCG ACA GTC GGG TTC AGA GAA AAT ACA GAT AT - #T GCG GAG AAA TGG GTT630 Ala Thr Val Gly Phe Arg Glu Asn Thr Asp Il - #e Ala Glu Lys Trp Val185 - # 190 - # 195 - - CAG CTC TTT AGC ACT CCG TAC TTC ATG GTC TC - #A GCT GTT GAA GAT GTT678 Gln Leu Phe Ser Thr Pro Tyr Phe Met Val Se - #r Ala Val Glu Asp Val 200 2 - #05 2 - #10 2 -#15 - - GAA GGA GTA GAA CTT TGT GGA ACA CTG AAG AA - #T ATC GTG GCC ATAGCA 726 Glu Gly Val Glu Leu Cys Gly Thr Leu Lys As - #n Ile Val Ala Ile Ala 220 - # 225 - # 230 - - GCC GGT TTT GTG GAT GGA TTG GAG ATG GGA AA - #C AAC ACA AAA GCA GCA774 Ala Gly Phe Val Asp Gly Leu Glu Met Gly As - #n Asn Thr Lys Ala Ala 235 - # 240 - # 245 - - ATT ATG AGG ATC GGG TTA CGG GAG ATG AAG GC - #A TTC TCC AAG CTT TTG822 Ile Met Arg Ile Gly Leu Arg Glu Met Lys Al - #a Phe Ser Lys Leu Leu 250 - # 255 - # 260 - - TTT CCA TCT GTT AAG GAC ACT ACT TTC TTC GA - #G AGC TGT GGA GTT GCT870 Phe Pro Ser Val Lys Asp Thr Thr Phe Phe Gl - #u Ser Cys Gly Val Ala265 - # 270 - # 275 - - GAC CTC ATC ACA ACT TGT TTG GGC GGG AGA AA - #C AGA AAA GTT GCT GAG918 Asp Leu Ile Thr Thr Cys Leu Gly Gly Arg As - #n Arg Lys Val Ala Glu 280 2 - #85 2 - #90 2 -#95 - - GCT TTT GCA AAG AAT GGC GGG GAA AGG TCA TT - #C GAT GAT CTC GAAGCA 966 Ala Phe Ala Lys Asn Gly Gly Glu Arg Ser Ph - #e Asp Asp Leu Glu Ala 300 - # 305 - # 310 - - GAG CTG CTC CGG GGG CAA AAA TTA CAG GGT GT - #C TCA ACA GCA AAG GAG 1014 Glu Leu Leu Arg Gly Gln Lys Leu Gln Gly Va - #l Ser Thr Ala Lys Glu 315 - # 320 - # 325 - - GTC TAT GAA GTC TTG GGG CAC CGA GGC TGG CT - #C GAG CTG TTC CCG CTC 1062 Val Tyr Glu Val Leu Gly His Arg Gly Trp Le - #u Glu Leu Phe Pro Leu 330 - # 335 - # 340 - - TTC TCA ACC GTG CAC GAG ATC TCC ACT GGC CG - #T CTG CAT CCT TCA GCC 1110 Phe Ser Thr Val His Glu Ile Ser Thr Gly Ar - #g Leu His Pro Ser Ala345 - # 350 - # 355 - - ATC GTC GAA TAC AGC GAA CAA AAA ACC ATC TT - #C TCT TGG TAGAGCAAGA 1159 Ile Val Glu Tyr Ser Glu Gln Lys Thr Ile Ph - #e Ser Trp 360 3 - #65 3 - #70 - - GGCTGCCCTT GAAAGACTAA GAGCCACCCT GCCCTGTTTA AAGGGCTAAA AG -#TTTAATAT 1219 - - TTCTCTGCAG CCTAAACAGT TGGAAACATT GAAAATCTAG GATGTATCAG AA -#AAAAGAAG 1279 - - GTTTGGAGGA AGTATGGATG ATATAGAGGA CATGAATGTA TTCATTTTCG GT -#ATACTCTT 1339 - - TTTCTGCAAA ATAATTCTTC AGATGTAAAA AAAAAAAAAA AAAAACTCGA G - # 1390 - - - - (2) INFORMATION FOR SEQ ID NO:8: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 372 amino - #acids (B) TYPE: amino acid (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: protein - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:8: - - Met Ala Pro Ser Glu Leu Asn Cys Thr His Gl - #n Asn Pro His Ser Ser 1 5 - # 10 - # 15 - - Gly Tyr Asp Gly Pro Arg Ser Arg Val Thr Va - #l Val Gly Ser Gly Asn 20 - # 25 - # 30 - - Trp Gly Ser Val Ala Ala Lys Leu Ile Ala Se - #r Asn Thr Leu Lys Leu 35 - # 40 - # 45 - - Pro Ser Phe His Asp Glu Val Arg Met Trp Va - #l Phe Glu Glu Thr Leu 50 - # 55 - # 60 - - Pro Ser Gly Glu Lys Leu Thr Asp Val Ile As - #n Gln Thr Asn Glu Asn 65 - # 70 - # 75 - # 80 - - Val Lys Tyr Leu Pro Gly Ile Lys Leu Gly Ar - #g Asn Val Val Ala Asp 85 - # 90 - # 95 - - Pro Asp Leu Glu Asn Ala Val Lys Asp Ala As - #n Met Leu Val Phe Val 100 - # 105 - # 110 - - Thr Pro His Gln Phe Met Glu Gly Ile Cys Ly - #s Arg Leu Val Gly Lys 115 - # 120 - # 125 - - Ile Gln Glu Gly Ala Gln Ala Leu Ser Leu Il - #e Lys Gly Met Glu Val130 - # 135 - # 140 - - Lys Met Glu Gly Pro Cys Met Ile Ser Ser Le - #u Ile Ser Asp Leu Leu 145 1 - #50 1 - #55 1 -#60 - - Gly Ile Asn Cys Cys Val Leu Met Gly Ala As - #n Ile Ala Asn GluIle 165 - # 170 - # 175 - - Ala Val Glu Lys Phe Ser Glu Ala Thr Val Gl - #y Phe Arg Glu Asn Thr 180 - # 185 - # 190 - - Asp Ile Ala Glu Lys Trp Val Gln Leu Phe Se - #r Thr Pro Tyr Phe Met 195 - # 200 - # 205 - - Val Ser Ala Val Glu Asp Val Glu Gly Val Gl - #u Leu Cys Gly Thr Leu210 - # 215 - # 220 - - Lys Asn Ile Val Ala Ile Ala Ala Gly Phe Va - #l Asp Gly Leu Glu Met 225 2 - #30 2 - #35 2 -#40 - - Gly Asn Asn Thr Lys Ala Ala Ile Met Arg Il - #e Gly Leu Arg GluMet 245 - # 250 - # 255 - - Lys Ala Phe Ser Lys Leu Leu Phe Pro Ser Va - #l Lys Asp Thr Thr Phe 260 - # 265 - # 270 - - Phe Glu Ser Cys Gly Val Ala Asp Leu Ile Th - #r Thr Cys Leu Gly Gly 275 - # 280 - # 285 - - Arg Asn Arg Lys Val Ala Glu Ala Phe Ala Ly - #s Asn Gly Gly Glu Arg290 - # 295 - # 300 - - Ser Phe Asp Asp Leu Glu Ala Glu Leu Leu Ar - #g Gly Gln Lys Leu Gln 305 3 - #10 3 - #15 3 -#20 - - Gly Val Ser Thr Ala Lys Glu Val Tyr Glu Va - #l Leu Gly His ArgGly 325 - # 330 - # 335 - - Trp Leu Glu Leu Phe Pro Leu Phe Ser Thr Va - #l His Glu Ile Ser Thr 340 - # 345 - # 350 - - Gly Arg Leu His Pro Ser Ala Ile Val Glu Ty - #r Ser Glu Gln Lys Thr 355 - # 360 - # 365 - - Ile Phe Ser Trp370 - - - - (2) INFORMATION FOR SEQ ID NO:9: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 4434 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: DNA (genomic) - - (iii) HYPOTHETICAL: NO - - (iv) ANTI-SENSE: NO - - (vi) ORIGINAL SOURCE: (A) ORGANISM: Cuphea la - #nceolata - - (vii) IMMEDIATE SOURCE: (A) LIBRARY: Genomic la - #mbda FIX II (B) CLONE: C1GPDHg5 - - (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: join(1394..1 - #550, 2066..2142, 2241..2313,2405 ..2622, 2 - #719..2826, 2961..3024, 3223..3260, 3342 ..3462, 3 - #541..3595, 3692..3740, 3850..4005) - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:9: - - GGATCCTTAG AAGACAAGCG CGGGGCGGGC ATGGGTCTCG TGATACCCGC CC -#CATTTTGC 60 - - CCCATTCCAT CCCTATATGG TAAGCAGATC TCACTGAAAA GTCACCGTTT CT -#GGATGGTT 120 - - TCCAGATGAT TTTGTCCCTC CCTCTAGCTG CATTAGGTGA TGGGATTGAG GC -#TATTCTAA 180 - - GAACCAGCTC GTGTGGAAGG TAGGCGGAGA TTAGCTCCCA GTTCCATCCT CC -#TGTATTTG 240 - - AAGCGAAGAA AGAAACTGGG TTGTCTAGCA TGTTTTGTGG GACAGGTTTG GT -#CGTCTTTT 300 - - CTGATAGGCT CTGATTCAAT AGAAGCCAAT TATCTCTCCA AAAGGAAACC TT -#ATTACCAC 360 - - TTCCAATCGA CCACCCTATG TACTTGCTGA TCTTCGGCCA GGTATCGCAT AA -#AGCATTCC 420 - - ATAACGCTGA TGCTGTCGTC TTTTTTGTGA ATGTTGGCAA GAGTGTGTCT GG -#CATGGCAT 480 - - ATTTGTGACT GAGCACCCGC ACCCAAAGGC TCTGAGGTTG TGATGCCATA TC -#CCAACATA 540 - - CCTTCGATAG AAAGGCTTCA TTCATCTTCC GTAGCTTACG AATGCCAAGA CC -#ACCCCATG 600 - - GTGCTGGACT AGTGACCGTG GACCAATTGA CCAAATGCAC CTTCCTTTGC TC -#CATTGAAT 660 - - GGCCCCAAAT GAAGTTGCCG CAATGTCTTT CGATTTCATC AAGTGTTCCA TG -#AGGAATAC 720 - - GTGTGGACTG CATGGAGAAG GATGGCAGAG CCGTCAAGAC AGATTTCACC AG -#CGTCACCC 780 - - GCCCAGCCAT TGACAGTGTC GATGCCGACC AACCAGCAAG TCTTGCTTTT AC -#CTCGACAT 840 - - GTTTTGGATT TTATATACCG GTGGTGATGG TGTTTGAATT AATCATCGTC AT -#TAATTTAT 900 - - ACCGTGCAAT ATATATTGCA ACATTCCAAA GTATAATTAA TTTTATATGT CC -#ATTCGTGA 960 - - CTAATCTTGG AGATAGGGCT TAAATTGTTA TATGATGATA TAGAAGAAGT TG -#GATAGCAC 1020 - - ATAAGAACTC TATAAAATGC TTATAGATCA TGGCATCGAA TTCATCCGCT AT -#ATATGAGT 1080 - - GAGGAAGAAA CTAATCAAAA CCTCGTATTC ATCGAAACAA CCGTTGAAGT GG -#TTACACTT 1140 - - TGAATCCTAA GACATACTTG ACGTCATGAT TCTGTCTCTC TATTCCATTG CA -#TAATAAAT 1200 - - AAAACAAAGG AAACAAAAGC ATAGAGGAGA TCGCCAGATT CAGCAGTTTC CG -#CATAGGTT 1260 - - GCCACGGAGC CTTACATGCC GATGCCTTCC TCTGCCTCCT TCTTCCTCCT GT -#CTCTCTCT 1320 - - CTACATCCCC TTATATCCCT TCCTCCTTCC CTCCATCTTC ACCATTCCTC TG -#TTTTTCTT 1380 - - CTCAGCCTCT GCA ATG GCT CCC TCT GAG CTC AAC TG - #C ACC CAC CAG AAC1429 Met Ala - #Pro Ser Glu Leu Asn Cys Thr His Gln Asn 1 - # 5 - # 10 - - CCA CAT TCA AGC GGT TAC GAC GGA CCC AGA TC - #G AGG GTC ACC GTT GTC 1477 Pro His Ser Ser Gly Tyr Asp Gly Pro Arg Se - #r Arg Val Thr Val Val 15 - # 20 - # 25 - - GGT AGT GGA AAC TGG GGC AGT GTC GCT GCC AA - #G CTC ATT GCT TCC AAT 1525 Gly Ser Gly Asn Trp Gly Ser Val Ala Ala Ly - #s Leu Ile Ala Ser Asn 30 - # 35 - # 40 - - ACC CTC AAG CTT CCA TCT TTT CAT G GTTCGTC - #TCT CCTTTTCTCT 1570 Thr Leu Lys Leu Pro Ser Phe His 45 - # 50 - - GAAAAATGAA GCTTTTGCAT GGGATAGTCA CTAGATATGA GCCTCTGTTT GC -#ATGACTGA 1630 - - AGCGCTTGAG TAACCGAGTT TTTGGAACAA GAGCACAGGT GGTTCCTTTG CA -#TTTTCTTT 1690 - - GAGGTTCCTT AATCATTCAA TGAAGTAGCG GTTGATCGCT GAGCAATTGA AA -#CTTGTGGA 1750 - - ATCGAACCTC CAGCCGAGTC TTAGTGTAAT TGCTTTCTGT TTTACTTCAT TC -#ATAGTGGG 1810 - - AAGGAGTACG AACTGATGAG TGATGTCACA TTTCATTAGT CGGGTTGCGA AA -#AAACTCAG 1870 - - TTGACATATT GGTCGAGACT CTGCAGTGTC ATCAGATATG AGTTGGTGTA TT -#TGTATTGA 1930 - - CATTTGAATT TGGTATGTGT ATGAATTTTG TTGAATTAAT CACCGCTGTG AT -#GAAAAGAT 1990 - - CAGTACTTCT TCGGTCATTT TTCAGGTGGA AGGATGTTGG TTTCTTATAT AT -#GTAACTTT 2050 - - ACATGAATTT TTCAG AT GAA GTG AGA ATG TGG GTA - #TTT GAG GAG ACTCTA 2100 Asp - #Glu Val Arg Met Trp Val Phe Glu Glu Thr L - #eu - # 55 - # 60 - - CCG AGC GGC GAG AAG CTT ACT GAT GTC ATC AA - #C CAG ACC AAT - #2142 Pro Ser Gly Glu Lys Leu Thr Asp Val Ile As - #n Gln Thr Asn 65 - # 70 - # 75 - - GTAAGGAAAC ACAGATTAGC AATAGCATGA GCAGTTATTG CTGGTTAAAT AT -#GCTTGTTA 2202 - - GCAACTTTCG TGACGGCCTG AGTTTTATAC CTCTGCAG GAA AAT GTT - #AAG TAT 2255 - # - # Glu Asn Val Lys Tyr - # - # 80 - - CTC CCC GGA ATT AAG CTC GGT AGG AAT GTT GT - #T GCA GAT CCA GAC CTC 2303 Leu Pro Gly Ile Lys Leu Gly Arg Asn Val Va - #l Ala Asp Pro Asp Leu 85 - # 90 - # 95 - - GAA AAC GCA G GTAGTCCATG TGTTCATTAG AATTCTCTAA - #TTAATTATTG 2353 Glu Asn Ala 100 - - TGGTTTATTT CCTTGTCTCT GTGATGATAT TCTGGATGAA ATTTTGTGCA G - # TT AAG 2409 - # - # - # ValLys - - GAT GCA AAT ATG CTC GTG TTT GTG ACA CCG CA - #T CAG TTC ATG GAGGGC 2457 Asp Ala Asn Met Leu Val Phe Val Thr Pro Hi - #s Gln Phe Met Glu Gly 105 1 - #10 1 - #15 1 -#20 - - ATC TGC AAA AGA CTC GTA GGG AAA ATA CAG GA - #A GGA GCA CAG GCTCTC 2505 Ile Cys Lys Arg Leu Val Gly Lys Ile Gln Gl - #u Gly Ala Gln Ala Leu 125 - # 130 - # 135 - - TCC CTT ATA AAG GGC ATG GAG GTC AAA ATG GA - #G GGG CCT TGC ATG ATC 2553 Ser Leu Ile Lys Gly Met Glu Val Lys Met Gl - #u Gly Pro Cys Met Ile 140 - # 145 - # 150 - - TCG AGC CTA ATC TCT GAT CTT CTC GGG ATC AA - #C TGC TGT GTC CTA ATG 2601 Ser Ser Leu Ile Ser Asp Leu Leu Gly Ile As - #n Cys Cys Val Leu Met 155 - # 160 - # 165 - - GGG GCA AAC ATC GCT AAT GAG GTAAACACTT GGCACGATC - #T GGTTGCAACT 2652 Gly Ala Asn Ile Ala Asn Glu170 - # 175 - - CCCCCAGGAA ATTGTAGATC CTCATACTGT TAGCATCTTG ATGAGGTTAA AT -#ATCTTATG 2712 - - TTGTAG ATT GCT GTT GAG AAA TTC AGT GAA GCG - #ACA GTC GGG TTC AGA 2760 Ile Ala Val Glu Lys Phe Se - #r Glu Ala Thr Val Gly Phe Arg - # 180 - # 185 - - GAA AAT ACA GAT ATT GCG GAG AAA TGG GTT CA - #G CTC TTT AGC ACT CCG 2808 Glu Asn Thr Asp Ile Ala Glu Lys Trp Val Gl - #n Leu Phe Ser Thr Pro 190 1 - #95 2 - #00 2 -#05 - - TAC TTC ATG GTC TCA GCT GTAAGTTGCG ATAAAACCTT AC - #GTTTTGCT2856 Tyr Phe Met Val Ser Ala 210 - - AATAGAACAC AATGCTAGAA ACTCCCAGAT TTCAATGTTA TGTATTTTGG TG -#CCCAAAGA 2916 - - AGCAACTTCT TAACATCTGT GGCTCCTCTT ACTGACAAAA ATAG GTT G - #AA GATGTT 2972 - # - # Val Glu Asp -#Val - # - # - #215 - - GAA GGA GTA GAA CTT TGT GGA ACA CTG AAG AA - #T ATC GTG GCC ATAGCA 3020 Glu Gly Val Glu Leu Cys Gly Thr Leu Lys As - #n Ile Val Ala Ile Ala 220 - # 225 - # 230 - - GCC G GTTCGTGTTT ACGAGATGTA CATTTATGTA TAACAATCTT - #TCATTTATTC 3074 Ala - - ATCGAGATGG GATGCAATAT ATCAATGAGA GGGAAAAGAA AGGGCAAAGG AA -#AATGCTGT 3134 - - TGTATTGCAG CTTTAGGCAT TCTTTTCTCT TAATTATTAA CTGTGAAACA CC -#GAGAAGTA 3194 - - TTGATGAAGT TAAGAAACGA TGTTACAG GT TTT GTG GAT G - #GA TTG GAG ATG3245 - # Gly Phe Val - #Asp Gly Leu Glu Met - # - # 235 - # 240 - - GGA AAC AAC ACA AAA GTAAGTCTAA ATTTTTTGTA AAACTTAAA - #G TAAGAGTTTA 3300 Gly Asn Asn Thr Lys 245 - - TGCTTTGGCA TTGTTTGAAG TTCACTTACT AATGACTTTA G GCA GCA - #ATT ATG 3353 - # - # Ala Ala Ile Met - - AGG ATC GGG TTA CGG GAG ATG AAG GCA TTC TC - #C AAG CTT TTG TTT CCA 3401 Arg Ile Gly Leu Arg Glu Met Lys Ala Phe Se - #r Lys Leu Leu Phe Pro 250 2 - #55 2 - #60 2 -#65 - - TCT GTT AAG GAC ACT ACT TTC TTC GAG AGC TG - #T GGA GTT GCT GACCTC 3449 Ser Val Lys Asp Thr Thr Phe Phe Glu Ser Cy - #s Gly Val Ala Asp Leu 270 - # 275 - # 280 - - ATC ACA ACT TGT T GTAAGGAAGC ATATAGATTT CCTTCGA - #ATA TGAATAAATT 3502 Ile Thr Thr Cys 285 - - GCATAGTTCA TATCATCATA ATTTGTGTTT GTGCTCAG TG GGC G - #GG AGA AAC 3554 - # - # Leu Gly Gly Arg Asn - # - # - # 290 - - AGA AAA GTT GCT GAG GCT TTT GCA AAG AAT GG - #C GGG GAA AG - # 3595 Arg Lys Val Ala Glu Ala Phe Ala Lys Asn Gl - #y Gly Glu Arg 295 - # 300 - - GTCGTGTTTC CCTTTCGTCG ATCCTGATTT AATTCCTGTT TAGTGGTATT CA -#CTTTGTGT 3655 - - GTATGTAAAT CAAGCAACTA TTTCCATCAT CTTCAG G TCA TTC G - #AT GAT CTC3707 - # - # Ser Phe Asp Asp Leu - # - # 305 - - GAA GCA GAG CTG CTC CGG GGG CAA AAA TTA CA - #G GTACATGATG AAGAAACCGA 3760 Glu Ala Glu Leu Leu Arg Gly Gln Lys Leu Gl - #n 310 3 - #15 3 - #20 - - TGTCTATACA GAAAGAGTCC ATTGCAAAGC TTGAGAATGT TTCGAGCATA AA -#GAGCATAA 3820 - - GAATATTCTT TTCGGTGATT TTCATGCAG GGT GTC TCA ACA GCA - # AAG GAGGTC 3873 - # Gly Val S - #er Thr Ala Lys Glu Val - # - # 325 - - TAT GAA GTC TTG GGG CAC CGA GGC TGG CTC GA - #G CTG TTC CCG CTC TTC 3921 Tyr Glu Val Leu Gly His Arg Gly Trp Leu Gl - #u Leu Phe Pro Leu Phe330 - # 335 - # 340 - - TCA ACC GTG CAC GAG ATC TCC ACT GGC CGT CT - #G CAT CCT TCA GCC ATC 3969 Ser Thr Val His Glu Ile Ser Thr Gly Arg Le - #u His Pro Ser Ala Ile 345 3 - #50 3 - #55 3 -#60 - - GTC GAA TAC AGC GAA CAA AAA ACC ATC TTC TC - #T TGG TAGAGCAAGA4015 Val Glu Tyr Ser Glu Gln Lys Thr Ile Phe Se - #r Trp 365 - # 370 - - GGCTGCCCTT GAAAGACTAA GAGCCACCCT GCCCTGTTTA AAGGGCTAAA AG -#TTTAATAT 4075 - - TTCTCTGCAG CCTAAACAGT TGGAAACATT GAAAATCTAG GATGTATCAG AA -#AAAAGAAG 4135 - - GTTTGGAGGA AGTATGGATG ATATAGAGGA CATGAATGTA TTCATTTTCG GT -#ATACTCTT 4195 - - TTTCTGCAAA ATAATTCTTC AGATGTTTTT GTGGTATGAG ATATAGAGGA CA -#TGTATGTA 4255 - - TGCGGTAAGG CTGAAGTAAA CAAGTTACCA TAAGAGACAG CCCTCTCGGT TT -#CTTCCATC 4315 - - TGATCGATTC GTCTCGTCGA ATTTGCCAAA AGCTCAAAAC TCAACTCATC CC -#CTGCTTTC 4375 - - TATCCATATG GGCAAGGAAT ACAATTAGAC CAGTTTGATA CTTGTAATGA GA -#AGTTTAC 4434 - - - - (2) INFORMATION FOR SEQ ID NO:10: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 372 amino - #acids (B) TYPE: amino acid (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: protein - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:10: - - Met Ala Pro Ser Glu Leu Asn Cys Thr His Gl - #n Asn Pro His SerSer 1 5 - # 10 - # 15 - - Gly Tyr Asp Gly Pro Arg Ser Arg Val Thr Va - #l Val Gly Ser Gly Asn 20 - # 25 - # 30 - - Trp Gly Ser Val Ala Ala Lys Leu Ile Ala Se - #r Asn Thr Leu Lys Leu 35 - # 40 - # 45 - - Pro Ser Phe His Asp Glu Val Arg Met Trp Va - #l Phe Glu Glu Thr Leu50 - # 55 - # 60 - - Pro Ser Gly Glu Lys Leu Thr Asp Val Ile As - #n Gln Thr Asn Glu Asn 65 - #70 - #75 - #80 - - Val Lys Tyr Leu Pro Gly Ile Lys Leu Gly Ar - #g Asn Val Val Ala Asp 85 - # 90 - # 95 - - Pro Asp Leu Glu Asn Ala Val Lys Asp Ala As - #n Met Leu Val Phe Val 100 - # 105 - # 110 - - Thr Pro His Gln Phe Met Glu Gly Ile Cys Ly - #s Arg Leu Val Gly Lys 115 - # 120 - # 125 - - Ile Gln Glu Gly Ala Gln Ala Leu Ser Leu Il - #e Lys Gly Met Glu Val130 - # 135 - # 140 - - Lys Met Glu Gly Pro Cys Met Ile Ser Ser Le - #u Ile Ser Asp Leu Leu 145 1 - #50 1 - #55 1 -#60 - - Gly Ile Asn Cys Cys Val Leu Met Gly Ala As - #n Ile Ala Asn GluIle 165 - # 170 - # 175 - - Ala Val Glu Lys Phe Ser Glu Ala Thr Val Gl - #y Phe Arg Glu Asn Thr 180 - # 185 - # 190 - - Asp Ile Ala Glu Lys Trp Val Gln Leu Phe Se - #r Thr Pro Tyr Phe Met 195 - # 200 - # 205 - - Val Ser Ala Val Glu Asp Val Glu Gly Val Gl - #u Leu Cys Gly Thr Leu210 - # 215 - # 220 - - Lys Asn Ile Val Ala Ile Ala Ala Gly Phe Va - #l Asp Gly Leu Glu Met 225 2 - #30 2 - #35 2 -#40 - - Gly Asn Asn Thr Lys Ala Ala Ile Met Arg Il - #e Gly Leu Arg GluMet 245 - # 250 - # 255 - - Lys Ala Phe Ser Lys Leu Leu Phe Pro Ser Va - #l Lys Asp Thr Thr Phe 260 - # 265 - # 270 - - Phe Glu Ser Cys Gly Val Ala Asp Leu Ile Th - #r Thr Cys Leu Gly Gly 275 - # 280 - # 285 - - Arg Asn Arg Lys Val Ala Glu Ala Phe Ala Ly - #s Asn Gly Gly Glu Arg290 - # 295 - # 300 - - Ser Phe Asp Asp Leu Glu Ala Glu Leu Leu Ar - #g Gly Gln Lys Leu Gln 305 3 - #10 3 - #15 3 -#20 - - Gly Val Ser Thr Ala Lys Glu Val Tyr Glu Va - #l Leu Gly His ArgGly 325 - # 330 - # 335 - - Trp Leu Glu Leu Phe Pro Leu Phe Ser Thr Va - #l His Glu Ile Ser Thr 340 - # 345 - # 350 - - Gly Arg Leu His Pro Ser Ala Ile Val Glu Ty - #r Ser Glu Gln Lys Thr 355 - # 360 - # 365 - - Ile Phe Ser Trp370 - - - - (2) INFORMATION FOR SEQ ID NO:11: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 2955 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: DNA (genomic) - - (iii) HYPOTHETICAL: NO - - (iv) ANTI-SENSE: NO - - (vi) ORIGINAL SOURCE: (A) ORGANISM: Cuphea la - #nceolata - - (vii) IMMEDIATE SOURCE: (A) LIBRARY: Genomic la - #mbda FIX II (B) CLONE: C1GPDHg3 - - (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: join(1182..1 - #326, 1837..1913, 2010..2082,2180 ..2397, 2 - #480..2587, 2668..2731, 2848..2885, 2947 ..2955) - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:11: - - GGATCCTCCT CGATGGTGGT CCAATGAAGA CTATACAAAA CCAAGCCGAC GG -#AATCCGGT 60 - - GCACAATAAC TTGAAGCCAT GAAAACCAAT GCAATATATA GAGTACGCCT TG -#TACTATGT 120 - - AATATATTTA CAATTTTCTC TTGAATAGTT TAGGTTTGGT GATCGTAAAC TC -#GCAAAACA 180 - - CATATGTGCG TGTGTAAATA TATCTGGTGA TGATGTATGA AGAGAGTGCG GT -#TTAATTAC 240 - - CCGGTATTGT ATAAGGTTGT ATCTGCAGTT GACACTTTCA GTAGAAATTA CT -#AATAACTC 300 - - GACGAGATAC AAACGACTCG AGTTTCAGAA ATAAGTGGCA AAACGTTATG GG -#GTTCTCCT 360 - - TGATTCTTCG TGGAAGGTAT ACTATTAATC ATGTTCGCCT CCGTCCTAGT AG -#AAACATAG 420 - - AGTTTTTATC GGGATGCAGA TTGCAGATGA TAGAACTATT GTCAGATTCA TT -#ATGCATAT 480 - - AGGATAGGCC TTCTACTGAT TTGGAAACTT ATATCGATTC TGTTGGAATG GA -#TGTATGAA 540 - - AAGCTTCATA TCCGACATTG AAAATTTGGT CATATCAATA AGATGAACTA AC -#AAAATATG 600 - - CCAACCTCTT GGAAGCAAAA CACATCCGAG ACTTTAAGAT GTGGCTGAGG TT -#TCTGCAAC 660 - - TTTAAATCTC CCATATGCTT GACAGAATTG GTAGACCTAA CTCAATGGAT TT -#CATTCAAT 720 - - GATCGAAGTT TCTCTATCGA TCATAGCTGT GAATTAGTAA GCAAATGTCC AT -#AATATATC 780 - - CCCGAAAACA CGTAAAGTTA GGTCTCATTA CATTAGGCCT CAACCATATG TT -#ATAAGTAA 840 - - ATTTGTTTTT TTTTTTTTCT CTTACAGTTG AATGTATCAA ATCGAAAAAA CC -#GTTAAGTC 900 - - GTTGCGGCCC TTTGAATAGT AAGCCAAAGA TCCGAAAGAA AAAGTAAACA GA -#GACAGAGC 960 - - AATGAGGAGA TGGCCAGTTT GAGAAGCAAA CGCATAGGTT GCCACGGAGG AG -#GCGGAGAC 1020 - - GGGTCATCGA TGACTTTCTC CGCCTCCTTA ACCGCAATGG CGATGCCGCC AT -#ACCTCTCT 1080 - - GTCACCCTCT CTCCATTCCC TTTATATCTC TCCCGCTTCT TCCTCTGCTC CA -#CTCAACCC 1140 - - CCTCTGCATA AACTCTGTGC TTTTTTAGTC TCTCCCCTGC T ATG TCG - #CCG GCA 1193 - # - # Met Ser Pro Ala - # - # 1 - - TTC GAA CCC CAT CAG CAG AAG CCT ACC ATG GA - #G AAC ATG CGA TTC CGA 1241 Phe Glu Pro His Gln Gln Lys Pro Thr Met Gl - #u Asn Met Arg Phe Arg 5 - # 10 - # 15 - # 20 - - GTC ACC ATC ATT GGC AGC GGT AAC TGG GGC AG - #C GTC GCC GCT AAG CTC 1289 Val Thr Ile Ile Gly Ser Gly Asn Trp Gly Se - #r Val Ala Ala Lys Leu 25 - # 30 - # 35 - - ATT GCC TCC AAC ACC CTC AAC CTC CCG TCT TT - #C CAC G GTTTGTCTGC 1336 Ile Ala Ser Asn Thr Leu Asn Leu Pro Ser Ph - #e His 40 - # 45 - - CACTCTTCTT TCTTCATGAT CAGGCTCTTG CCAGTAGAGA CATGTCTTTT CA -#TGAATCAA 1396 - - GCACCCGTTT TTTCGATGAG GATCACTGAG TTTGATTTAA GGGTATCCGA TG -#CAACTGCT 1456 - - GAAAAGATGT GGTTATTTTT GTTCTTTCAT GAAGTATCAT CTGAGAAATT TG -#ATCTTAGC 1516 - - CTAAGCGGCA TTACTTTCGG TGTTAAGTTC ATTCTATGTG AGTAGGAGTA TG -#AGGTGATG 1576 - - CCGCGTGATT CCAATCAGGT ACCGATGAAA ATCAGTAGAC ATGGTTGCAG TT -#GAGGTTCC 1636 - - ATAGTTTACA CAGCATAGGA GTTGCTGTAT TTCTATTGAC GCTTGGATTT GT -#TTGGTGCT 1696 - - TATAATCCCG GTTTTTACTA ATTGGTTATG AACACCGATA ATAACAACAG TT -#AGATTTCT 1756 - - TCAACATTAA CCGGTTGAAG ATTAGGCCAT ATTCTTATTT GGGTACTATT TC -#TTAAGAAA 1816 - - ACATTCATAT TTTCTTTCAG AT GAA GTA AGG ATG TGG - #GTG TTT GAG GAG 1865 - # Asp Glu Val Arg Met Trp Val Phe - #Glu Glu - # 50 - # 55 - - ACA TTG CCA AGC GGC GAG AAG CTC ACT GAA GT - #C ATC AAC CGG ACC AAT 1913 Thr Leu Pro Ser Gly Glu Lys Leu Thr Glu Va - #l Ile Asn Arg Thr Asn 60 - # 65 - # 70 - - GTAAGGAAGA TCAATTTAGC ATGTCATTGT ATTAACATAA AGAGCGTTTA TT -#GGCAACTT 1973 - - TGGCTTTCAT GATGTTCGAG TGTTGCGTCT TTGCAG GAA AAT GTT - #AAG TAT CTG 2027 - # - # Glu Asn Val Lys Tyr Leu - # - # 75 - # 80 - - CCT GGA TTC AAG CTT GGC AGA AAT GTT ATT GC - #A GAC CCA AAC CTT GAA 2075 Pro Gly Phe Lys Leu Gly Arg Asn Val Ile Al - #a Asp Pro Asn Leu Glu 85 - # 90 - # 95 - - AAT GCA G GTAGTGATTG TATTTCAGTG CTCGGTTGAA TGATCAA - #GTA AAATCCTCGT 2132 Asn Ala - - GCTAAATATG TCGAGATGTT CGTGTTTTTG CATAATGTTT TGTTTAG T - #T AAG GAA 2187 - # - # Val - #Lys Glu - # - # - # 100 - - GCA AAC ATG CTT GTA TTT GTC ACA CCG CAT CA - #G TTC GTG GAG GGC CTT 2235 Ala Asn Met Leu Val Phe Val Thr Pro His Gl - #n Phe Val Glu Gly Leu 105 - # 110 - # 115 - - TGC AAG AGA CTC GTC GGG AAG ATA AAG GCA GG - #T GCA GAG GCT CTC TCC 2283 Cys Lys Arg Leu Val Gly Lys Ile Lys Ala Gl - #y Ala Glu Ala Leu Ser 120 - # 125 - # 130 - - CTT ATA AAG GGC ATG GAG GTC AAA AGG GAA GG - #G CCT TCC ATG ATA TCT 2331 Leu Ile Lys Gly Met Glu Val Lys Arg Glu Gl - #y Pro Ser Met Ile Ser135 - # 140 - # 145 - - ACC TTA ATC TCG AGC CTT CTC GGG ATC AAC TG - #C TGT GTC CTA ATG GGA 2379 Thr Leu Ile Ser Ser Leu Leu Gly Ile Asn Cy - #s Cys Val Leu Met Gly 150 1 - #55 1 - #60 1 -#65 - - GCA AAC ATC GCC AAC GAG GTAAAATCTT GGTGCAGTCT TA - #CGAGATTC2427 Ala Asn Ile Ala Asn Glu 170 - - TGAATCTTGA ACCTGTTAGC ATTTTGACAC ACTGTGACTT CTAAATTTGT AG - # ATT 2482 - # - # - # Ile - - GCT CTT GAG AAA TTC AGT GAG GCG ACA GTC GG - #A TAC AGA GAA AAT AAG 2530 Ala Leu Glu Lys Phe Ser Glu Ala Thr Val Gl - #y Tyr Arg Glu Asn Lys 175 - # 180 - # 185 - - GAT ACT GCA GAG AAA TGG GTT CGG CTC TTC AA - #C ACT CCA TAC TTC CAA 2578 Asp Thr Ala Glu Lys Trp Val Arg Leu Phe As - #n Thr Pro Tyr Phe Gln190 - # 195 - # 200 - - GTC TCG TCT GTGAGTACGA ATAAACCTTT CCTTCTGCGA ACAAAAAAC - #T 2627 Val Ser Ser 205 - - TCCCGAGGCA GGAACTAAAT GAAACAAGTT AACATAATAG GTT CAA GA - #T GTG GAA 2682 - # - # Val Gln Asp Val Glu - # - # 210 - - GGA GTG GAA CTT TGT GGC ACA CTG AAG AAT GT - #C GTG GCC ATA GCA GCC G 2731 Gly Val Glu Leu Cys Gly Thr Leu Lys Asn Va - #l Val Ala Ile Ala Ala 215 - # 220 - # 225 - - GTACTTATAT ACGATCTCCA CATTTATATA AACTAGTTAG AAAGATTTTG GA -#TTGCTGTA 2791 - - AAAACCGTGG AAAAACCCGA AAAGTGTTGA TGAAGTGTTA CCAAATGTTG TT - #TCAGGT 2849 - # - # - #Gly - - TTT GTA GAT GGA CTG GAG ATG GGA AAC AAC AC - #A AAG GTAAGTCCAA2895 Phe Val Asp Gly Leu Glu Met Gly Asn Asn Th - #r Lys 230 2 - #35 2 - #40 - - AGTTCATGCA AATTTTTTCG TATTTACGAC TGAATGCTTG GATATACATA G - #GCT GCG 2952 - # - # - # AlaAla - - ATT - # - # - # 2955 Ile - - - - (2) INFORMATION FOR SEQ ID NO:12: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 244 amino - #acids (B) TYPE: amino acid (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: protein - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:12: - - Met Ser Pro Ala Phe Glu Pro His Gln Gln Ly - #s Pro Thr Met Glu Asn 1 5 - # 10 - # 15 - - Met Arg Phe Arg Val Thr Ile Ile Gly Ser Gl - #y Asn Trp Gly Ser Val 20 - # 25 - # 30 - - Ala Ala Lys Leu Ile Ala Ser Asn Thr Leu As - #n Leu Pro Ser Phe His 35 - # 40 - # 45 - - Asp Glu Val Arg Met Trp Val Phe Glu Glu Th - #r Leu Pro Ser Gly Glu50 - # 55 - # 60 - - Lys Leu Thr Glu Val Ile Asn Arg Thr Asn Gl - #u Asn Val Lys Tyr Leu 65 - #70 - #75 - #80 - - Pro Gly Phe Lys Leu Gly Arg Asn Val Ile Al - #a Asp Pro Asn Leu Glu 85 - # 90 - # 95 - - Asn Ala Val Lys Glu Ala Asn Met Leu Val Ph - #e Val Thr Pro His Gln 100 - # 105 - # 110 - - Phe Val Glu Gly Leu Cys Lys Arg Leu Val Gl - #y Lys Ile Lys Ala Gly 115 - # 120 - # 125 - - Ala Glu Ala Leu Ser Leu Ile Lys Gly Met Gl - #u Val Lys Arg Glu Gly130 - # 135 - # 140 - - Pro Ser Met Ile Ser Thr Leu Ile Ser Ser Le - #u Leu Gly Ile Asn Cys 145 1 - #50 1 - #55 1 -#60 - - Cys Val Leu Met Gly Ala Asn Ile Ala Asn Gl - #u Ile Ala Leu GluLys 165 - # 170 - # 175 - - Phe Ser Glu Ala Thr Val Gly Tyr Arg Glu As - #n Lys Asp Thr Ala Glu 180 - # 185 - # 190 - - Lys Trp Val Arg Leu Phe Asn Thr Pro Tyr Ph - #e Gln Val Ser Ser Val 195 - # 200 - # 205 - - Gln Asp Val Glu Gly Val Glu Leu Cys Gly Th - #r Leu Lys Asn Val Val210 - # 215 - # 220 - - Ala Ile Ala Ala Gly Phe Val Asp Gly Leu Gl - #u Met Gly Asn Asn Thr 225 2 - #30 2 - #35 2 -#40 - - Lys Ala Ala Ile - - - - (2) INFORMATION FOR SEQ ID NO:13: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 574 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: DNA (genomic) - - (iii) HYPOTHETICAL: NO - - (iv) ANTI-SENSE: NO - - (vi) ORIGINAL SOURCE: (A) ORGANISM: Cuphea la - #nceolata - - (vii) IMMEDIATE SOURCE: (A) LIBRARY: Genomic la - #mbda FIX II (B) CLONE: C1GPDHg3 - - (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: 31..189 - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:13: - - GGCATATCGA TGATTTTTCC TATCTTGCAG GGT GTC TTG ACA GC - #A AAA GAGGTG 54 - # Gly Val - #Leu Thr Ala Lys Glu Val - # 1 - # 5 - - TAT GAG GTA CTG AAG CAC CGG GGC TGG CTC GA - #G CGT TTC CCG CTC TTC102 Tyr Glu Val Leu Lys His Arg Gly Trp Leu Gl - #u Arg Phe Pro Leu Phe 10 - # 15 - # 20 - - GCA ACT GTG CAT GAG ATC TCA TCT GGC AGG TT - #G CCT CCT TCA GCC ATT150 Ala Thr Val His Glu Ile Ser Ser Gly Arg Le - #u Pro Pro Ser Ala Ile 25 - # 30 - # 35 - # 40 - - GTC AAA TAC AGC GAA CAA AAG CCC GTC TTA TC - #T CGA GGT TAGAACGAGA199 Val Lys Tyr Ser Glu Gln Lys Pro Val Leu Se - #r Arg Gly 45 - # 50 - - GAAAACCCGA CAAACCGGTG AAACTCGTAG TCTTAAACTG AAATCCAAAA AC -#ATGCTGGG 259 - - AACATCAGCA AAAACCATTC ATCAAGGATG TCTTAGATAA AAGGTTTCAG GA -#AGAAATAG 319 - - ATGGTAGTGT GTGTAATGTT ATCAGCAATC ATTCATTCAT TTATTAAGTA TT -#TTTTGCAT 379 - - CATATTTTAT GCTAATAATT ATTACATAAA TTACTCAAAT TTTGTCAAAA TT -#TCTGCATT 439 - - GCCCCAAACA GATTAATGCA TTGAGAAAAA CTTATAAAGC TTTATCCAGC AT -#ACATATAG 499 - - TTCTTTAAGC AATACAAAAA CACCCTTCTA AGCCTCTTTG AAGATGGAGT TT -#GATCACAC 559 - - ATTAAAATGC TTTTT - # - #- # 574 - - - - (2) INFORMATION FOR SEQ ID NO:14: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 53 amino - #acids (B) TYPE: amino acid (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: protein - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:14: - - Gly Val Leu Thr Ala Lys Glu Val Tyr Glu Va - #l Leu Lys His Arg Gly 1 5 - # 10 - # 15 - - Trp Leu Glu Arg Phe Pro Leu Phe Ala Thr Va - #l His Glu Ile Ser Ser 20 - # 25 - # 30 - - Gly Arg Leu Pro Pro Ser Ala Ile Val Lys Ty - #r Ser Glu Gln Lys Pro 35 - # 40 - # 45 - - Val Leu Ser Arg Gly 50 - - - - (2) INFORMATION FOR SEQ ID NO:15: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 1507 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: DNA (genomic) - - (iii) HYPOTHETICAL: NO - - (iv) ANTI-SENSE: NO - - (vi) ORIGINAL SOURCE: (A) ORGANISM: Cuphea la - #nceolata - - (vii) IMMEDIATE SOURCE: (A) LIBRARY: Genomic la - #mbda FIX II (B) CLONE: C1GPDHg9 - - (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: 1193..1375 - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:15: - - GCATGCGGGC AGGCAGGCAG GCATGGGTCT AAATTCTAGA AGACCCAGAC AT -#ATTCATTT 60 - - TGTTCACAAC CGACCCATCA ATATATTGAT TAATTTTGTT TAAATTTATC AT -#CAGTTTTT 120 - - ATTTAATATT TTTAAATAGG TTTACCTTGA TCGTGATAAT TATTTAATAT TA -#CTTTGTAA 180 - - TAGTTTATTT ATCTAGCGTT ATAAAATAAC ATTTGAATTC GTTGATGATA TG -#TGTATTTT 240 - - TACTATGTTT ATATGAAATT TATATTTCAA ATATTAAATA ATGTTCTTAT TT -#TGGCCTAT 300 - - GGAGAAGTAT CATCAATTTT TCTATTAAAT AACAGTCTTC AGTTTAGTCA AA -#TCAGTTGA 360 - - TAAGTTCCCA AATCACACAT TGTTTGTATG AAAATTTTAA TAAAAAAGTT AA -#GATGGTAT 420 - - TATTATAGAA AAATATATAA AGTATCTTTA AATAATAATT TCTTTTTAAT AC -#AAAAGGAA 480 - - ATATTTGATT ACTTGACTTA TAAAATTTAT TGATAAGGAT GCCAACTTTC AT -#TTTAGAAA 540 - - CTAGAGTAAT GATGGTTAAA TTCCCCGAAA AATGGTATGT CAATTTATTG AT -#ACGTTCCA 600 - - CTACTAATTT CTGAGACATT TACATGTTTG TAAAAAAAAT CTATATATTT AA -#ATTAAGAT 660 - - GGGTGTAATC AATTATAAAA TACAGCGAAT TTTAACACCG AATGAATAGA TT -#ATCTGCAT 720 - - AACAATTTAT ACCATCCCTA AATACGAATT AGCAAGTTAA TAAAATTTAA TT -#ACACGAAC 780 - - CATGATTATA TAAATTATCG AATCCCCGAC GTGGGGACGT ACCGAACCAA CC -#GTTGAAGT 840 - - GGTTGCCCTT TGAATCCTAA GACATACAGA CGTCATGATT CTTTGTCTCT CT -#ATCTGTCC 900 - - ATTTACATAA TAAAATCAAA GAGAAGAAAA CAGAGGAAGC AGAGCATAGC AT -#AGCATAGC 960 - - ATAGAGGAGA TCGCCAGATT CAGCTGTTTC CTCATAGTTT GCCACGAGAC AT -#ACATTGCA 1020 - - TTGCCCGATG CCTTTCTCCG CCTCCTTGTC CCTCTCCTCA TTCCCCCGAT GC -#CTTTCTCC 1080 - - GCCTCCTTGT CCCTCTCCTC ATTCCCTTAT ATCCCTCCTC CCCTCCCTCT TC -#TTCCTCTG 1140 - - CTCAACTCCT CCCCCTCACC CTCTTCCTCT GTTCTTCCTC TCTGCCTCTG CA - # ATG1195 - # - # - # Met - # - # - # 1 - - GCG CCT GCC TTC GAA CCC CAT CAG CTG GTT CC - #T TCT GAG CTT AAC TCT 1243 Ala Pro Ala Phe Glu Pro His Gln Leu Val Pr - #o Ser Glu Leu Asn Ser 5 - # 10 - # 15 - - GCC CAC CAG AAC CCA CAT TCC AGC GGA TAT GA - #A GGA CCC AGA TCG AGG 1291 Ala His Gln Asn Pro His Ser Ser Gly Tyr Gl - #u Gly Pro Arg Ser Arg 20 - # 25 - # 30 - - GTC ACC GTC GTT GGC AGC GGC AAC TGG GGC AG - #C GTC GCT GCC AAG CTC 1339 Val Thr Val Val Gly Ser Gly Asn Trp Gly Se - #r Val Ala Ala Lys Leu 35 - # 40 - # 45 - - ATT GCT TCC AAC ACC CTC AAG CTC CCA TCT TT - #C CAT GGTTAGTCTC 1385 Ile Ala Ser Asn Thr Leu Lys Leu Pro Ser Ph - #e His 50 - # 55 - # 60 - - TCATTCTTCT CTCTGTAAAG TTGAAGCTTT TTCATGGAAT AGTCTCTAGA CA -#TGAGCCCC 1445 - - TGTTTGCATG GTTTTGTTTT GTCTTTGAAA CATGAATAAA GGTGGTTTCT TG -#TGTTGGTA 1505 - - CC - # - # - # 1507 - - - - (2) INFORMATION FOR SEQ ID NO:16: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 61 amino - #acids (B) TYPE: amino acid (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: protein - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:16: - - Met Ala Pro Ala Phe Glu Pro His Gln Leu Va - #l Pro Ser Glu Leu Asn 1 5 - # 10 - # 15 - - Ser Ala His Gln Asn Pro His Ser Ser Gly Ty - #r Glu Gly Pro Arg Ser 20 - # 25 - # 30 - - Arg Val Thr Val Val Gly Ser Gly Asn Trp Gl - #y Ser Val Ala Ala Lys 35 - # 40 - # 45 - - Leu Ile Ala Ser Asn Thr Leu Lys Leu Pro Se - #r Phe His 50 - # 55 - # 60 - - - - (2) INFORMATION FOR SEQ ID NO:17: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 349 amino - #acids (B) TYPE: amino acid (D) TOPOLOGY: linear - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:17: - - Met Ala Gly Lys Lys Val Cys Ile Val Gly Se - #r Gly Asn Trp Gly Ser 1 5 - # 10 - # 15 - - Ala Ile Ala Lys Ile Val Gly Ser Asn Ala Gl - #y Arg Leu Ala His Phe 20 - # 25 - # 30 - - Asp Pro Arg Val Thr Met Trp Val Phe Glu Gl - #u Asp Ile Gly Gly Arg 35 - # 40 - # 45 - - Lys Leu Thr Glu Ile Ile Asn Thr Gln His Gl - #u Asn Val Lys Tyr Leu50 - # 55 - # 60 - - Pro Gly His Lys Leu Pro Pro Asn Val Val Al - #a Ile Pro Asp Val Val 65 - #70 - #75 - #80 - - Gln Ala Ala Thr Gly Ala Asp Ile Leu Val Ph - #e Val Val Pro His Gln 85 - # 90 - # 95 - - Phe Ile Gly Lys Ile Cys Asp Gln Leu Lys Gl - #y His Leu Lys Ala Asn 100 - # 105 - # 110 - - Thr Ile Gly Ile Ser Leu Ile Lys Gly Val As - #p Glu Gly Pro Asn Gly 115 - # 120 - # 125 - - Leu Lys Leu Ile Ser Glu Val Ile Gly Glu Ar - #g Leu Gly Ile Pro Met130 - # 135 - # 140 - - Ser Val Leu Met Gly Ala Asn Ile Ala Ser Gl - #u Val Ala Glu Glu Lys 145 1 - #50 1 - #55 1 -#60 - - Phe Cys Glu Thr Thr Ile Gly Cys Lys Asp Pr - #o Ala Gln Gly GlnLeu 165 - # 170 - # 175 - - Leu Lys Asp Leu Met Gln Thr Pro Asn Phe Ar - #g Ile Thr Val Val Gln 180 - # 185 - # 190 - - Glu Val Asp Thr Val Glu Ile Cys Gly Ala Le - #u Lys Asn Ile Val Ala 195 - # 200 - # 205 - - Val Gly Ala Gly Phe Cys Asp Gly Leu Gly Ph - #e Gly Asp Asn Thr Lys210 - # 215 - # 220 - - Ala Ala Val Ile Arg Leu Gly Leu Met Glu Me - #t Ile Ala Phe Ala Lys 225 2 - #30 2 - #35 2 -#40 - - Leu Phe Cys Ser Gly Thr Val Ser Ser Ala Th - #r Phe Leu Glu SerCys 245 - # 250 - # 255 - - Gly Val Ala Asp Leu Ile Thr Thr Cys Tyr Gl - #y Gly Arg Asn Arg Lys 260 - # 265 - # 270 - - Val Ala Glu Ala Phe Ala Arg Thr Gly Lys Se - #r Ile Glu Gln Leu Glu 275 - # 280 - # 285 - - Lys Glu Met Leu Asn Gly Gln Lys Leu Gln Gl - #y Pro Gln Thr Ala Arg290 - # 295 - # 300 - - Glu Leu His Ser Ile Leu Gln His Lys Gly Le - #u Val Asp Lys Phe Pro 305 3 - #10 3 - #15 3 -#20 - - Leu Phe Thr Ala Val Tyr Lys Val Cys Tyr Gl - #u Gly Gln Pro ValGly 325 - # 330 - # 335 - - Glu Phe Ile Arg Cys Leu Gln Asn His Pro Gl - #u His Met 340 - # 345__________________________________________________________________________ | This invention discloses isolated DNA sequences encoding a glycerol-3-phosphate dehydrogenase, particularly DNA sequences isolated from Cuphea lanceolata. The invention also describes genomic clones from Cuphea lanceolata which contain the complete gene for glycerol-3-phosphate dehydrogenase including promoter sequences. The DNA sequences and clones of the invention are useful for the production of transgenic plants. | 2 |
BACKGROUND AND SUMMARY OF THE INVENTION
This application claims the priority of German Patent Document 100 43 631.5, the disclosure of which is expressly incorporated by reference.
The present invention relates to a linear operating device that includes a medium for converting a rotational motion into a translational motion, which is realized as a nut, a rotating drive unit and a spindle, which acts in conjunction with the nut; and the nut is connected with the spindle in such a manner that it maintains its ability to rotate.
A linear operating device of this type is known from European Patent Document EP 0 603 067. This linear operating device is envisioned particularly for use on spacecraft. In this instance the nut is realized as a thread rolling mechanism. The spindle is connected with torsional strength to a rotating drive unit.
As an alternative to the thread rolling mechanism referred to above, a ball nut is known from German Patent Document DE 42 08 126 and corresponding U.S. Pat. No. 5,263,381, which also acts in conjunction with a spindle to convert a rotational motion into a translational motion.
In the context of the present state of the art in accordance with European Patent Document EP 0 603 067, the spindle of the linear drive is always connected to the rotating drive unit. Elements that are connected with the nut can be moved in a translational way in relation to the spindle, or, in the extreme consequence, they can even be detached from the spindle. However, this is accompanied by the risk that with larger elements that are to be moved in a translational manner or with elements that are to be connected temporarily with the spindle it will be necessary to use a spindle that is correspondingly large and that will, after release of the connection between the nut and the spindle, remain as a relatively large and disturbing element on the rotating drive unit and possible other components that are attached to the rotating drive unit. With regard to the example of the unfolding of a solar generator on a spaceship, this would mean that after the solar generator has been unfolded a relatively long spindle would stick out from the surface of the spaceship that could obstruct the movement of the solar generator, or even cause damage to the solar generator.
Specifically, with respect to the case of an unfolding system for solar generators, different construction types are known from German Patent Document DE 196 49 739 and corresponding U.S. Pat. No. 6,073,914, but they are associated with certain disadvantages. A pyrotechnical release entails the problem that a relatively high shock acts upon the solar generator unit and/or on the structures carrying it, which would, in spacecraft applications, cause considerable disturbances. In addition, there exists a risk of particles flying about that can result in damage to the solar generator apparatus or other mechanisms. German Patent Document DE 196 49 739 also discloses non-pyrotechnical release devices. However, these devices are also associated with the risk of particles flying about or with the risk, as in the embodiment claimed in German Patent Document DE 196 49 739, of a jam-up. Consequently, a failure to release cannot be precluded.
It is therefore an object of the present invention to provide a linear operating device that will remedy the disadvantages of the state of the art referred to above and that allows, particularly in the context of the application in space travel, operation without shock effect or particles flying about.
The objective is achieved with the rotating drive unit being rotatably fixed to the nut or the rotating drive unit exercising a force in an axial direction of the spindle on an area of the spindle that acts in conjunction with the nut. Other certain preferred embodiments of the present invention include a spacecraft and a solar generator unfolding system featuring a linear operating device.
The linear operating device preferentially includes a rotating drive unit rotatably fixed to the nut. Consequently, by way of a rotational motion of the nut, which is caused by the rotating drive unit, it is possible to generate a translational motion of the spindle, which, in the ultimate consequence, will result in the detachment of the spindle from the nut. This way, the spindle, that may be very long, no longer stays on the rotating drive unit and the components attached to it. The rotating drive unit can be realized, for example, as a motor or as a spring.
In further certain preferred embodiments, it is also possible to envision as an alternative or in conjunction with the preferred embodiments referred to above that one (or, if need be, another or even several) rotating drive unit(s) exercise(s) a force in the axial direction of the spindle in that area of the spindle that acts in conjunction with the nut. Thus, it is possible to cause the nut to rotate, solely by or supported by the effect of this tensile load or pressure load, which effects in turn a translational movement of the spindle. In this case, the rotating drive unit can be realized as an elastic element.
In particular in certain preferred embodiments, it can be envisioned that the spindle is realized as pre-stressed and extensible. To be considered in this context are all kinds of suitable materials and construction types for the spindle, which, obviously, must be adjusted to the respective pre-stress. The spindle can be manufactured, for example, from titanium or steel in order to absorb high pre-stresses, and it can be manufactured as a solid element or as individual elements, such as fibers or rods, in order to provide a correspondingly lower or higher level of elasticity. Other suitable materials, for example non-metallic materials, or other construction types are also possible.
On the other hand, in certain preferred embodiments, it is also possible to envision, in the alternative or in addition, that at least one elastic element, for example a spring element, is envisioned as rotating drive unit, which exercises a pre-stress, i.e. a tensile load or a pressure load, on the spindle. Thus, analogous to the previous description, this elastic element is then able to cause the nut to rotate by way of applying the tensile load or pressure load upon the spindle.
In certain preferred embodiments, the nut has an operative connection with the spindle via rolling bodies. This ensures that during the rotational motion of the nut, with regard to the spindle, only the rolling resistance must be overcome, but no sliding resistance occurs between the nut and the spindle. Envisioned as suitable rolling bodies can be, for example, rollers or balls that are known from the state of the art referred to previously.
In certain preferred embodiments, in order to stop the nut before it executes the rotational motion, it is possible to envision a lock device, where the nut is attached to a first lock device rotatably fixed. This lock device can be part of the nut itself, but it is also possible to envision another element to which the nut is suitably attached with torsional strength. The first lock device is realized in such a way that it can be connected, detachably and rotatably fixed, to a complementary lock device. This way it can be guaranteed that, provided both lock devices are in a stop position, they are arresting any rotational motion of the nut, and after the lock devices are released from each other the nut is able to execute the desired rotational motion. To accomplish this, the first lock device can be equipped with a projection or a recess on its surface, while the complementary lock device features a form that is complementary to the projection or the recess. The only requirement for this complementary form is that it is realized appropriately in such a way that it can act effectively in conjunction with the projection or the recess in order to block any undesired rotating of the nut.
To ensure tension-free operation of the linear operating device, it can be envisioned that the spindle and the nut are arranged in mountings with the ability to tilt. This way it is possible to make adjustments for any mutual displacement of the mountings of spindle and nut. Consequently, the mountings are realized in a suitable form, preferentially as ball-and-socket joint or in another appropriate way.
This linear operating device can be used in all instances where items must be connected in such a way that they are displaceable in relation to each other, and particularly where items are to be detachably connected with each other and are to be released subsequently, e.g. released within the meaning of opening, extending, folding out or separating. Thus, this is a device that provides a solid connection in its reeled-in condition which can then be easily released, particularly by also applying remote activation.
In other certain preferred embodiments of the present invention, a spacecraft is equipped with the linear operating device described previously. The rotating drive unit can, for example, be connected to the spacecraft, and the spindle can be connected to detachable, extendable or unfoldable mechanisms of the spacecraft. Devices of this type can be, for example, solar generator units or antenna devices of the spacecraft, other masts, landing legs, loads that are to be put out, several spacecrafts (for example, satellite piles) or even a parent or secondary spacecraft that is to be separated from the other craft, respectively.
In certain preferred embodiments of the present invention, a solar generator unfolding system is equipped with the linear operating device described above. In this instance, the linear operating device can be envisioned particularly as part of a hold-down and release system for unfolding a solar generator unit.
In certain preferred embodiments, it can be envisioned that the nut is connected to a supporting structure of the solar generator unit and that the spindle is connected to an outermost panel element of the solar generator unit. This way it is possible to ensure that upon unfolding of the solar generator unit the spindle will be removed from the supporting structure, e.g. a solid frame, a vehicle, a spacecraft etc., so that it cannot be the cause of disruptions at that location.
To guarantee tension-free operation it is possible to envision that the spindle is arranged in a first mounting with the ability to tilt vis-à-vis the outermost panel element of the solar generator unit, and the nut is arranged in a second mounting with the ability to tilt vis-à-vis the support structure. Thus, any possible displacement of the solar generator unit vis-à-vis the support structure can be compensated for in a simple manner.
Preferred embodiments of the present invention are subsequently described in more detail using the FIGS. 1 to 6 .
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a plain view of a solar generator unfolding system, including a linear operating device according to certain preferred embodiments of the invention;
FIG. 2 shows a cross section of the hold-down mechanism for the spindle of the unfolding system in accordance with FIG. 1 ;
FIG. 3 shows a schematic depiction of the nut, including a lock device;
FIG. 4 shows a view of the connection of a spring as rotating drive unit with the nut;
FIG. 5 shows a cross section of one of the nuts, which is realized as a ball nut; and
FIG. 6 shows a cross section of the apparatus in accordance with FIG. 1 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
FIG. 1 shows a linear operating device according to a preferred embodiment of the invention that is part of a solar generator unfolding system, a spacecraft, for example. This apparatus includes a nut 1 that is used to detachably anchor a spindle 3 . Subject to a pre-stress, a solar generator unit 8 is held together and/or held down over this spindle 3 . FIG. 1 indicates sections of individual panel elements of the solar generator unit 8 . The spindle 3 is connected with torsional strength by way of a corresponding connecting element 13 , for example a ball cup, with the solar generator unit. The connecting element 13 can be aligned in such a way that it is possible to apply via the spindle 3 a tensile stress as pre-stress, which is intended to hold solar generator unit 8 together and/or down. This pre-stress can be applied, for example, by way of another nut 15 to the one end of the spindle 3 , while on its other end the spindle 3 is fastened inside the nut 1 .
The amount of the pre-stress can be selected in such a way that spindle 3 undergoes an extension. This will turn the spindle into a rotating drive unit 22 , because, as soon as the nut 1 allows it, the spindle 3 will attempt to re-contract thereby causing the nut 1 to rotate, which in turn causes the spindle 3 to be moved out of the nut 1 in the form of a linear motion. If the spindle 3 is a solid material, the expansion will occur along its entire length. However, it is also possible for the spindle 3 to have a certain elasticity only in a partial area with that area being, for example, a more elastic material or of a different structure, such as individual elements (e.g. fibers, rods etc.).
In the alternative or to support this pre-stress effect resulting from the extension of the spindle 3 , it is possible to envision one or several springs 32 that exercise a pre-stress on the spindle 3 itself, and the pre-stress is then passed along to the nut 1 via the spindle 3 . Thus, using a measure such as this it is also possible to set the spindle 3 under a pre-stress vis-à-vis the nut 1 . Again, a tensile load is applied that causes the nut 1 to rotate as soon as the nut allows this to occur, whereby, consequently, the spindle 3 is moved out of the nut 1 in the form of a linear movement. Thus, in this case the spring 32 constitutes a rotating drive unit. However, instead of a spring 32 that applies a tensile load, it is also possible to envision a suitable elastic element that applies a pressure load on the spindle 3 and that acts upon the spindle 3 , for example, on the end of the spindle that is directed toward the nut 1 . This would mean that the spindle 3 is not partially pulled out of the nut 1 , but instead it is partially pushed out in order to cause the nut 1 to rotate, which will cause the spindle 3 to be finally completely moved out of the nut 1 .
A further alternative or additional possibility to effect such a moving-out motion of the spindle 3 from inside of the nut 1 envisions a rotating drive unit 2 that is rotatably fixed to the nut. This will be described in more detail later.
Therefore, by rotating the nut 1 it is possible to generate a translational motion of the spindle 3 that will ultimately lead to the separation of the spindle 3 from the nut 1 , consequently causing the release of the composite unit including spindle 3 and solar generator unit 8 , connected to the spindle via the connecting element 13 , from the hold-down system, which is formed by the nut and the components connected to it.
The nut 1 can be realized, as shown for example in FIG. 5 , as a roller nut, i.e. the nut 1 is equipped with rollers 4 that establish in turn the operative connection with the spindle 3 , which is threaded, like the rollers 4 , at least along a section of its length.
To prevent any undesired rotational motion of the nut a stop mechanism including a lock device 5 is envisioned, which is depicted in FIG. 3 . In the present example, this is a sleeve 5 into which the nut 1 is fitted rotatably fixed. In an area of its surface, the sleeve 5 features a projection 7 that allows for blocking the rotational motion of the composite unit including the sleeve 5 and nut 1 by way of a second lock device 6 , for example a rod, a bolt etc.
As can be seen in FIGS. 1 , 2 and 4 , the sleeve 5 is connected rotatably fixed to a rotating drive unit 2 , which is realized as a spring 2 in the present case. In the present example, a spiral spring 2 is envisioned for this purpose that is in a pre-stressed condition before the nut 1 performs the rotational motion. After the stop is released, i.e. the lock devices 6 and 7 are detached from each other, it effects, due to its relaxing, a rotational motion of the sleeve 5 which entails therefore also a rotational motion of the nut 1 that is attached to the sleeve 5 . The other rotating drive units 22 , 32 can be envisioned, as has been outlined previously, as alternative or additional rotating drive units. For the purpose of simplifying the depiction in FIG. 1 , all three types of rotational drive units 2 , 22 , 32 are shown together.
In order to guarantee a safe rotational motion the aggregate unit of the nut 1 , sleeve 5 and spiral spring 2 is arranged, as shown in FIG. 2 , inside a housing 9 that is connected to a floor plate 14 or e.g. directly to the surface of the spacecraft. To reduce friction during the rotational motion of the sleeve 5 and of the nut 1 inside the housing 9 a corresponding bearing 10 , for example a roller bearing, is envisioned between the sleeve 5 and the housing 9 in the upper area of the housing.
The two lock devices 6 , 7 can be detached from one another using any kind of suitable device. The example in FIG. 1 envisions correspondingly that the lock device 6 is realized as a bolt connected to a traveler 20 via a toggle joint 11 ; and the traveler 20 can be moved, for example, using an actuator 12 , such as a motor or a solenoid. The translational motion of the traveler 20 is converted via the toggle joint 11 to a translational motion of the bolt 6 which becomes detached from the projection 7 during this movement, thereby releasing the rotational motion of the sleeve 5 and of the nut 1 that is attached with the sleeve 5 . It is also possible to use other suitable devices as lock device 6 or actuator 12 , such as shape memory alloys, etc.
FIG. 6 shows, once again, a cross section of the apparatus according to FIG. 1 , and the elements of the linear operating device described in the context of FIG. 1 are also seen again in FIG. 6 . Only the depiction of the spring 2 has been left out; as described previously, depending on the embodied example, this spring is not necessary. But, the depiction according to FIG. 6 emphasizes one detail in particular. Ball-and-socket joints are envisioned for arranging the spindle in the upper area, on the one hand, and for arranging the nut 1 and the sleeve 5 in the housing 9 , on the other hand. They compensate for any displacement at these two mounting points in relation to each other, i.e. a slanted position of the spindle, which is why despite such a displacement no tension results in the context of the apparatus, and particularly in the context of the spindle 3 as well as its mounting points.
Rather, the spindle 3 can be tilted vis-à-vis the uppermost solar generator unit 8 in the upper mounting as connecting element 13 in the same manner as the sleeve 5 with the nut 1 vis-à-vis the housing 9 in the mounting 15 in the upper area of the housing 9 . This guarantees stress-free operation of this apparatus until such a time that the spindle 3 is completely detached from the nut 1 .
The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since notification so the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof. | A linear operating device is provided that includes a way of converting a rotational motion into a translational motion, realized in the form of a nut, a rotating drive unit and a spindle acting in conjunction with the nut; and the nut is connected to the spindle with the ability to rotate. The rotating drive unit is connected to the nut with torsional strength, or it exercises a force in the axial direction of the spindle. Applications for the invention can be found in space travel, particularly in the context of solar generator unfolding systems. | 8 |
BACKGROUND OF THE INVENTION
The invention relates to a method for metering fuel from a high pressure system, comprising at least one high pressure pump, one pressure accumulator and one high pressure injection valve, into an exhaust gas duct of an internal combustion engine in order to regenerate a nitrogen oxide storage catalytic converter disposed in the exhaust gas duct, wherein a high pressure of the fuel is generated by the electrically actuated high pressure pump, which discretely delivers the fuel and has a constant stroke volume, wherein the fuel is supplied to the pressure accumulator comprising a pressure measuring device for determining the fuel pressure and wherein the fuel is injected into the exhaust gas duct via the downstream, electrically actuated high pressure injection valve.
The invention relates further to a method for metering fuel from a high pressure system, comprising at least one high pressure pump, one pressure accumulator and one high pressure injection valve, into an exhaust gas duct of an internal combustion engine in order to regenerate a particle filter disposed in the exhaust gas duct, wherein a higher pressure of the fuel is generated by the electrically actuated high pressure pump, which directly delivers the fuel and has a constant stroke volume, wherein the fuel is supplied to the pressure accumulator comprising a pressure measuring device for determining the fuel pressure and wherein the fuel is injected into the exhaust gas duct via the downstream, electrically actuated high pressure injection valve.
The invention further relates to a control unit for carrying out the method.
In order to reduce toxic emissions of internal combustion engines, different catalysts and filters are provided today in exhaust gas aftertreatment systems that are correspondingly provided. Thus, for example, in the case of diesel engines, diesel particle filters and NOx storage catalysts can be provided in addition to oxidation catalysts for oxidizing hydrocarbons and carbon monoxide.
Particle filters are used for reducing particle emissions. The exhaust gas is led through the particle filter, which separates out solid particles and retains said particles in a filter substrate. As a result of the soot masses embedded in the filter substrate, the particle filter becomes clogged with time. This fact is detected by an increase in the flow resistance and thereby in the exhaust gas back pressure. For this reason, the embedded soot mass must be discharged from time to time in a regeneration process. The regeneration is introduced by an increase in the exhaust gas temperature to typically 600° C. to 650° C., so that the soot embedded in the particle filter begins to burn off. In particular at low loads on the internal combustion engine and low rotational speeds of said internal combustion engine, measures inside the engine itself are to be provided in order to achieve the necessary temperatures for regeneration, for example in the fuel-mixture generation of the engine or by measures taken downstream of the engine such as an afterinjection (HCI: hydrocarbon injection) into the exhaust gas duct, which combusts at the oxidation catalyst. When the exhaust gas temperature is sufficiently high, an exothermal reaction is initiated in the particle filter, which causes a burn-off of the soot particles and regenerates said particle filter within a matter of minutes (e.g. 20 minutes).
NOx storage catalysts (NSC: NO x storage catalyst) serve to reduce the NO x emissions from internal combustion engines. During the operation of the internal combustion engine, NO 2 is embedded in the NO x storage catalyst. NO is thereby oxidized to NO 2 in an upstream oxidation catalyst. If the NO 2 storage limit of the NO x storage catalyst is achieved, said NO x storage catalyst must be regenerated. In order to provide the carbon monoxide necessary for this purpose, the exhaust gas must have a lambda value >1. In the case of lean running diesel engines, provision can also be made for the injection of fuel into the exhaust gas duct.
The German patent specification DE 10 2008 013 406 A1 describes a device for metering at least one emission reducing medium into an exhaust gas system, in particular for introducing fuel into an exhaust gas tract in order to regenerate an emission reducing element in the exhaust gas tract, comprising at least one injection valve, in particular a pressure-controlled injection valve, and at least one feed line for feeding the emission reducing medium to the injection valve, wherein at least one pressure damper is provided in the feed line upstream of the injection valve. In such a system, fuel from a low pressure system, which is supplied by a continuously operating low pressure pump, is, for example, metered via a metering valve and injected into the exhaust gas duct via the pressure-controlled injection valve.
Based on such a device, the German patent specification DE 10 2004 056 412 A1 describes a method for operating an internal combustion engine, in the exhaust gas region of which an exhaust gas treatment device is disposed, in which method a reagent is introduced into the exhaust gas region upstream of the exhaust gas treatment device, in which method initially an adjustable reagent safety valve (ReaCV), then a continuous reagent metering valve (ReaDV) and thereafter a reagent introduction check valve (ReaIV) are disposed in the direction of flow of the reagent, which is brought to a predefined reagent source pressure (pQRea), in which method the reagent pressure (pRea) is detected in the reagent path, which lies between the reagent metering valve (ReaDV) and the reagent introduction check valve (ReaIV), in which method the reagent pressure (pRea) detected in at least one predefined state of the reagent safety valve (ReaCV) and/or the reagent metering valve (ReaDV) is compared to at least one threshold value (pU, pabg, dpReaIV, pQRea, dpRea/dt) and a fault signal is outputted if the threshold value is exceeded. The method facilitates a check as to whether a leak is present in the reagent path and a check of the function of the valves provided therefore.
Aside from the low pressure injection systems described, metering systems are known, which introduce reagent into the exhaust gas duct at high pressures. Such systems are configured from a low pressure system and a high pressure system and facilitate, for example, the introduction of fuel into the exhaust gas duct. The low pressure system delivers the fuel from a tank to a high pressure pump of the high pressure system. The high pressure pump relates, for example, to a magnetically operated pump, which discretely delivers the fuel and has a constant stroke volume, which pump compresses the fuel to a high pressure, for example to 30 bar. The fuel is sprayed into the exhaust gas duct via a downstream high pressure accumulator, which can be embodied as a piston accumulator, and a high pressure injection valve (HDEV).
SUMMARY OF THE INVENTION
It is the aim of the invention to provide a control strategy for the regeneration of a nitrogen oxide storage catalyst (NSC) and a control strategy for the regeneration of a particle filter for a high pressure system for introducing fuel into an exhaust gas duct of an internal combustion engine.
It is furthermore the aim of the invention to provide a corresponding control unit for carrying out the method.
The aim of the invention, which relates to the method for regenerating a nitrogen oxide storage catalyst (NSC) disposed in the exhaust gas duct, is met by virtue of the fact that the high pressure pump is switched on and off by an actuation signal HDEV having a constant cycle duration T F , by virtue of the fact that the delivery volume of the high pressure pump is predefined by an actuation time T P per cycle, by virtue of the fact that the fuel quantity Q injected into the exhaust gas duct is extracted out of the pressure accumulator temporally independently of the actuation of the high pressure pump by means of opening the high pressure injection valve, by virtue of the fact that the high pressure pump is not actuated if the fuel pressure lies above a predefined target value and by virtue of the fact that the high pressure pump is actuated if the fuel pressure lies below the predefined target value.
The quantity of fuel required for the regeneration of the nitrogen oxide storage catalyst (NSC) can be extracted as required from the pressure volume of the pressure accumulator. Because the high pressure pump is only turned on if the fuel pressure in the high pressure system drops below a target value, the fuel pressure is held constant in a narrow control range by extracting fuel when fuel is injected into the exhaust gas duct, whereby an exact metering of the fuel quantity to be injected into the exhaust gas duct is made possible. The high pressure pump is thereby only operated as long as it is necessary to bring up the required quantity of injected fuel and fuel, which escapes via leaks out of the high pressure system. The pressure control can, for example, take place via a two-point controller.
Tolerances in the actually injected fuel quantity Q can thereby be reduced as a result of the high pressure pump not being actuated during the injection of fuel into the exhaust gas duct.
The frequency of actuation of the high pressure pump is predefined by means of the constant actuation frequency 1/T F . The delivery volume of the high pressure pump results from the actuation time T P per cycle, which preferably is designed for a delivery stroke of the high pressure pump. In order to achieve this end, provision can be made for the actuation time T P from a characteristic diagram to be predefined as a function of the fuel pressure and a supply voltage of the high pressure pump such that a full delivery stroke of the high pressure pump is achieved.
In the case of a high pressure pump which discretely delivers the fuel and has a constant stroke volume, the fuel volume delivered per unit of time results from the number of delivery strokes that have occurred in the unit of time. Within the framework of an on-board diagnostics, provision can be made for a leakage rate to be determined from a number of delivery strokes of the high pressure pump and the injected fuel quantity and for an error message to be outputted if the leakage rate exceeds a predefined threshold value. The leakage rate results from the difference between the fuel delivered by the high pressure pump per unit of time and the fuel injected into the exhaust gas duct in the unit of time. It is essential for the exact determination of the leakage rate that the fuel pressure be held within the limits of the control tolerance.
Aside from the delivered and the injected fuel volume, the leakage rate is a function of further parameters. Provision can therefore be made for further parameters, in particular the fuel pressure or the operating current of the high pressure pump, to be taken into account.
The aim of the invention relating to the method for regenerating a particle filter disposed in the exhaust gas duct of the internal combustion engine is met by virtue of the fact that a predetermined fuel quantity Q injected into the exhaust gas duct is predefined by an opening duration T E within a cycle T F of a cyclical actuation of the high pressure injection valve, by virtue of the fact that a post-delivery of fuel results by means of a cyclical actuation of the high pressure pump, which takes place synchronously to the actuation of the high pressure injection valve, such that the high pressure pump and the high pressure injection valve are actuated in a temporally displaced manner and not in an overlapping manner, by virtue of the fact that fuel quantity Q injected in a cycle and a maximum permissible leakage rate of the fuel out of the high pressure system is smaller than the fuel quantity required by a delivery stroke of the high pressure pump, by virtue of the fact that the high pressure pump is not actuated within a cycle if the fuel pressure lies above a predefined target value, by virtue of the fact that the high pressure pump is actuated if the fuel pressure lies below the predefined target value and by virtue of the fact that the fuel quantity Q injected in a cycle is varied in an adaptation process such that the high pressure pump is not actuated in a predefined, maximum proportion of cycles.
Fuel is extracted in an alternating manner from the high pressure system and subsequently fed back to the same by means of the synchronous, alternating actuation of the high pressure injection valve and the high pressure pump. The actuation of the high pressure pump is thereby preferably selected such that a delivery stroke having a delivery volume that is predefined by the geometry of the high pressure pump results per actuation. The fuel quantity Q injected into the exhaust gas duct per injection process is selected in such a manner that said quantity, together with a maximum admissible leakage rate from the high pressure system, can be post-delivered from the high pressure pump by means of a delivery stroke. In the case of an actual lower leakage rate, the high pressure pump delivers more fuel than is extracted from the high pressure system. For that reason, the high pressure pump is not actuated in several cycles as a result of the fuel pressure which then rises above the target value. The fuel pressure can thus be controlled in a narrow range, whereby an exact metering of the fuel quantity to be injected into the exhaust gas duct is made possible. It is furthermore ensured that fuel which escapes the high pressure system through leaks is sufficiently post-delivered. The adaptation process ensures that the delivery volume potential of the high pressure pump is fully utilized. The fuel quantity Q injected per injection process is thereby increased or respectively reduced until only a predefined proportion of delivery strokes is suppressed. Provision can thus be made for the injected fuel quantity Q to be adapted until only every twentieth delivery stroke is omitted, which corresponds to a delivery rate of 95% with respect to the maximum delivery rate of the high pressure pump. By means of the adaptation, an exemplar and temperature dependent leakage of the high pressure system can be compensated and does not have to be maximally held available by the high pressure pump in order to be able to safely adjust the target pressure even in the case of larger leakage rates. The fuel quantity injected into the exhaust gas duct per unit of time can be changed by means of the frequency 1/T F , with which the high pressure injection valve and the high pressure pump is actuated.
The control of the fuel pressure can occur via a two-point controller. The regeneration of a particle filter and the regeneration of a nitrogen oxide storage catalyst (NSC) can therefore take place via the same high pressure system and the same control unit, wherein only the different open-loop or closed-loop strategies described are provided for the different operating modes (regeneration of the particle filter and regeneration of the nitrogen oxide storage catalyst (NSC)).
In order to ensure a synchronous, temporally displaced actuation of the high pressure pump and the high pressure injection valve, provision can be made for the actuation of said high pressure pump and the actuation of said high pressure injection valve to occur temporally displaced by a half cycle.
The fuel quantity Q injected per injection process is set by a specification of the opening duration T E per cycle. Because, aside from the opening duration, the current fuel pressure can influence the quantity of injected fuel, provision can be made for the opening duration T E to be predefined as a function of the fuel pressure and the predetermined fuel quantity Q.
Corresponding to a preferred embodiment variant of the invention, provision can be made for the high pressure pump not to be actuated if the fuel pressure lies above a predefined target value that is increased by an admissible control deviation and for the high pressure pump to actuated if the fuel pressure lies below the predefined target value that is reduced by an admissible control deviation. The fuel pressure is thereby held constant within the framework of an admissible tolerance. An oscillation of the control loop is thus reliably prevented.
A sufficiently large fuel pressure can be achieved as a result of a fuel pressure greater than 10 bar, preferably greater than 25 bar, being generated by the high pressure pump.
The aim of the invention relating to the control unit is met by a control unit for actuating a high pressure pump and a high pressure injection valve of a high pressure system for metering fuel into an exhaust gas duct of an internal combustion engine in order to carry out the method described.
The method and the control unit can be used in a preferred manner for regenerating a nitrogen oxide storage catalyst (NSC) and a diesel particle filter (DPF) in the exhaust gas duct of a diesel engine.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained below in detail with the aid of an exemplary embodiment depicted in the figures. In the drawings:
FIG. 1 shows a high pressure system for introducing fuel into an exhaust gas duct in schematic depiction,
FIG. 2 shows a control strategy for regenerating a nitrogen oxide storage catalyst (NSC),
FIG. 3 shows a control strategy for regenerating a diesel particle filter (DPF).
DETAILED DESCRIPTION
FIG. 1 shows a high pressure system 10 for introducing fuel into an exhaust gas duct 5 of a diesel engine 6 in schematic depiction. Fuel, which is compressed to a pressure of 30 bar via a high pressure pump 11 , is supplied to the high pressure system 10 via a low pressure fuel supply 20 . The high pressure pump 11 is embodied as a magnetically operated HCI pump, which discretely delivers fuel and has a constant stroke volume. The compressed fuel arrives at a pressure accumulator 13 in the form of a piston accumulator via a pressure valve 12 , the pressure of the fuel that has built up being maintained by a piston in said piston accumulator. The fuel pressure is determined using a pressure measuring device 14 . The fuel is metered into the exhaust gas duct with a high pressure injection valve 16 .
Disturbance variables are leaks in the high pressure system 10 . Thus, a first fuel leak 21 at the high pressure pump 11 and a second fuel leak 22 at the pressure accumulator 13 along the piston 15 are depicted. Fuel, which escapes at the piston 15 out of the high pressure region of the pressure accumulator 13 , is fed via a fuel return 23 , for example, to a fuel tank or to the low pressure system of the fuel supply system.
The high pressure system 10 facilitates the regeneration of a nitrogen oxide storage catalyst (NSC) disposed in the exhaust gas duct and a diesel particle filter (DPF) likewise provided in the exhaust gas duct by means of an after-injection (HCI: hydrocarbon injection) combusting at an oxidation catalyst. A valve, like that used for the fuel metering in a gasoline direct injection (GDI), is provided as the high pressure injection valve 16 .
Different fuel dosages are required for the regeneration of the nitrogen oxide storage catalyst (NSC) and the diesel particle filter (DPF). This requires different control strategies for the high pressure system 10 for the two operating modes.
FIG. 2 shows a control strategy for regenerating a nitrogen oxide storage catalyst (NSC) with the high pressure system 10 depicted in FIG. 1 . An actuation signal HDEV 32 is depicted with respect to a first signal axis 30 . 1 and a first time axis 31 . 1 . A second diagram 41 shows an actuation signal: magnetic pump 33 with respect to a second signal axis 30 . 2 and a second time axis 31 . 2 . In a third diagram 42 , an enabling signal 34 is plotted with respect to a third signal axis 30 . 3 and a third time axis 31 . 3 . In a fourth diagram, a temporal course of a fuel pressure 37 is depicted with respect to a pressure axis 30 . 4 and a fourth time axis 31 . 4 . In addition, an upper limit 35 and a lower limit 36 for the fuel pressure 37 are plotted in the fourth diagram 43 .
The time axes 31 . 1 , 31 . 2 , 31 . 3 , 31 . 4 are scaled in the same way; and therefore the courses of the signals are simultaneously depicted one on top of the other in the four diagrams 40 , 41 , 42 , 43 .
The high pressure injection valve 16 shown in FIG. 1 is actuated by the actuation signal HDEV 32 and fuel is correspondingly metered from the high pressure system 10 into the exhaust gas duct 5 . The high pressure pump 11 is switched on and off by means of the actuation signal: magnetic pump 33 . The enabling signal 34 indicates the time periods in which the high pressure pump 11 can be switched on. The temporal course of the fuel pressure 37 measured in the pressure accumulator 13 depicted in FIG. 1 .
During the regeneration of the nitrogen oxide storage catalyst (NSC), the high pressure injection valve 16 is typically actuated having a cycle duration T D in the range of 2 to 4 seconds. The opening time T E per cycle T D is thereby predefined as a function of the required quantity of injected fuel and the fuel pressure 37 . The fuel pressure 37 drops in the high pressure system 10 by opening the high pressure injection valve 16 . If the fuel pressure 37 falls below the depicted lower limit 36 , the fuel delivery by the high pressure pump 11 is enabled by the enabling signal 34 via a corresponding two-point control. The high pressure pump 11 is actuated with a constant frequency 1/T F . In so doing, the actuation time T P per cycle T F is predefined from a characteristic diagram as a function of the fuel pressure 37 and a supply voltage U B of the high pressure pump 11 such that a complete delivery stroke of the high pressure pump 11 , which is designed as a magnetically operated HCI pump, is ensured. If the fuel pressure 37 reaches the upper limit 35 , the enabling signal 34 is reset and the actuation of the high pressure pump 11 is suspended. In order to reduce tolerances during the metering of the injected fuel quantity, the actuation of the high pressure pump 11 is suspended by a corresponding enabling signal 34 during the injection of the fuel into the exhaust gas duct.
The control strategy ensures that only the fuel quantity extracted from the high pressure system 10 by means of injection or leaks is post-delivered.
The delivery quantity per delivery stroke is known for the utilized high pressure pump 11 which discretely delivers fuel and has a constant stroke volume. At a known quantity of fuel injected into the exhaust gas duct, the current leakage rate from the high pressure system 11 can be determined from the number of delivery strokes and can be monitored within the framework of an on-board diagnostics (OBD). If the leakage rate exceeds a predefined threshold value, a corresponding error message can be outputted. At the same time, further sensor signals, such as fuel pressure 37 or the operating current of the high pressure pump 11 can be taken into account.
FIG. 3 shows a control strategy for regenerating a diesel particle filter (DPF) using the high pressure system 10 depicted in FIG. 1 . The same identifiers are thereby used as introduced with regard to FIG. 2 . A fifth diagram 44 shows the temporal course of the actuation signal HDV 32 , a sixth diagram 45 the actuation signal: magnetic pump 33 , a seventh diagram 46 the enabling signal 34 and an eighth diagram 47 the temporal course of the fuel pressure 37 .
During the regeneration of the diesel particle filter (DPF), the high pressure injection valve 16 and the high pressure pump 11 are synchronously actuated in an alternating manner with a frequency 1/T F . The actuation of the high pressure pump 11 is thereby temporally displaced by a half cycle T F with respect to the actuation of the high pressure injection valve 16 . The fuel is injected into the exhaust gas duct 5 with a constant quantity of injected fuel Q, which is post-delivered in each cycle of the high pressure pump 11 . The quantity of injected fuel Q is thereby selected such that a delivery stroke of the discretely conveying high pressure pump 11 compensates for the quantity of injected fuel Q and all leakages from the high pressure system 10 .
By means of the two-point control already described with regard to FIG. 2 , the actuation of the high pressure pump 11 is suspended in accordance with the depicted enabling signal 34 if the fuel pressure 37 exceeds the upper limit 35 . The quantity of injected fuel Q and the delivery quantity by the high pressure pump 11 are designed such that all admissible leakages are reliably compensated. For that reason, the delivery quantity of the high pressure pump 11 is greater than the fuel quantity extracted from the high pressure system 10 in the case of lower leakage rates. By means of this increasing delivery quantity, the fuel pressure 37 periodically rises above the upper limit 35 , whereby a delivery stroke of the high pressure pump 11 is cyclically omitted. In order to fully utilize the delivery quantity potential of the high pressure pump 11 , the quantity of injected fuel Q is increased or respectively again reduced via a slow adaptation up to maximally the geometric delivery volume of said high pressure pump 11 , until only a predefined proportion of delivery strokes is omitted. In so doing, exemplar and temperature dependent leakages during operation can be compensated, which without the adaptation have to be maximally taken into account in order to be able to reliably maintain the required fuel target pressure in the high pressure system 10 .
The control strategies depicted in FIG. 2 and FIG. 3 facilitate a demand appropriate injection of fuel into the exhaust gas duct 5 via the same two-point control for the high pressure systems 10 comprising high pressure pumps 11 that discretely deliver fuel and the regeneration of a nitrogen oxide storage catalyst (NSC) as well as the regeneration of a diesel particle filter (DPF). In so doing, a monitoring of the fuel leakage rate from the high pressure system 10 , for example within the framework of an on-board diagnostics (OBD), is possible. As a result of the learning function during the regeneration of the diesel particle filter (DPF), the influence of manufacturing variations and temperature on the leakage rate from the high pressure system 10 can be compensated, whereby the delivery quantity potential of the high pressure pump 11 can be fully utilized. | A method for metering fuel from a high pressure system, comprising at least one high pressure pump, one pressure accumulator and one high pressure injection valve, into an exhaust gas duct of an internal combustion engine in order to regenerate a nitrogen oxide storage catalyst (NSC) disposed in the exhaust gas duct, wherein a higher pressure of the fuel is generated by the electrically actuated high pressure pump, which discretely delivers fuel and has a constant stroke volume, wherein the fuel is supplied to the pressure accumulator comprising a pressure measuring device for determining the fuel pressure and wherein the fuel is injected into the exhaust gas duct via the downstream, electrically actuated high pressure injection valve. | 5 |
This application is a continuation application of U.S. patent application Ser. No. 10/974,079, filed Oct. 27, 2004, which is hereby incorporated by reference in its entirety.
BACKGROUND
Color and gray value digital images are both composed of picture elements (pixels), where each pixel is represented by multiple binary bits that define either a color or a gray level. In order to represent such an image on a bi-level printer, the individual color or gray level pixels are typically converted to binary level pixels through use of a digital halftoning process.
Digital halftoning is the process of transforming a continuous-tone image into a lower bit-depth, typically binary, image that has the illusion of the original continuous-tone image, using a careful arrangement of lower bit-depth picture elements. The process is also referred to as spatial dithering. In the case of color images, the color continuous-tone image is typically separated into color channels first. Separate halftones are then formed for each of the color channels.
Typically, for laser printers, ordered cluster dot halftones using lower lines per inch (lpi), such as 100-150 lpi, are best for photographs, areas of constant gray scale, or gradient patterns. Halftones using a lower lpi reduce print artifacts, such as banding, but may result in jagged edges for the sharp edges found in text and line art. Halftones using a higher lpi, such as 200-300 lpi, are best for text and line art, but are not as good for photographs, areas of constant gray scale, and gradient patterns. Print artifacts, such as banding, become more pronounced as the lpi is increased.
SUMMARY
One aspect of the present invention provides a printing system comprising a memory and a processor. The memory is configured to store image data representing an image. The processor is configured to perform a first digital halftone process on a first portion of the image and a second digital halftone process on a second portion of the image.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a block diagram illustrating one embodiment of major components of a printing system.
FIG. 1B is a block diagram illustrating another embodiment of major components of a printing system.
FIG. 2 is an image illustrating one embodiment of a 50% gray scale magnified letter “H.”
FIG. 3 is an image illustrating one embodiment of the magnified letter “H” after a digital halftone process has been applied to the image.
FIG. 4 is an image illustrating one embodiment of the magnified letter “H” after a dual digital halftone process has been applied to the image.
FIG. 5 is a flow diagram illustrating one embodiment of a method for applying a dual digital halftone process to an image.
DETAILED DESCRIPTION
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
FIG. 1A is a block diagram illustrating one embodiment of major components of a printing system 100 A. Printing system 100 A includes host or computer 102 and printer 120 . In one embodiment, printer 120 is a laser printer or laser print apparatus.
Computer 102 includes processor 104 , memory 108 , and input/output (I/O) interface 116 , which are communicatively coupled together via bus 106 . Driver 110 , data 112 to be printed, and image data 114 are stored in memory 108 . In one embodiment, driver 110 is executed by processor 104 to render data 112 to be printed into image data 114 , including performing a dual halftone process as described in further detail below with reference to FIGS. 2-5 . The data 112 to be printed may be any type of printable data, such as image files, word processing files, etc. In one embodiment, image data 114 comprises rows and columns, with one pixel defined at the intersection of each row and column. In one form of the invention, image data 114 includes a plurality of pixels, with each pixel being represented by a multi-bit value (i.e., each pixel is represented by an N-bit value, where N is greater than one). In one embodiment, each pixel in image data 114 is represented by a 2-bit value (e.g., black, white, and two gray levels). In another embodiment, each pixel in image data 114 is represented by a 4-bit value. In another embodiment, each pixel is represented by a 1-bit value (e.g., black and white).
Printer 120 includes processor 122 , I/O interface 126 , memory 128 , and laser print engine 130 , which are communicatively coupled together via bus 124 . I/O interface 126 of printer 120 is electrically coupled to I/O interface 116 of computer 102 through communication link 118 . In one embodiment, I/O interfaces 116 and 126 are serial interfaces, such as universal serial bus (USB) interfaces, and communication link 118 is a USB cable. In another embodiment, I/O interfaces 116 and 126 are network interfaces, and communication link 118 is a network, such as a local area network. In other embodiments, other types of interfaces and communication links may be used, including those for wireless communications.
After rendering data 112 into image data 114 , computer 102 outputs the image data 114 to printer 120 via communication link 118 . The received image data 114 is stored in memory 128 of printer 120 , where it is retrieved and processed by laser print engine 130 and printed to a medium. In one embodiment, image data 114 is compressed by computer 102 for transmission to printer 120 through communication link 118 . Image data 114 is then decompressed by printer 120 by firmware or dedicated hardware.
FIG. 1B is a block diagram illustrating another embodiment of major components of a printing system 100 B. Printing system 100 B includes similar hardware as printing system 100 A. But in system 100 B, image data 114 is rendered by printer 120 , rather than by computer 102 . In one embodiment, driver 140 converts data 112 to be printed into a description file 142 . In one form of the invention, driver 140 is a printer command language (PCL) driver for converting data 112 into a description file 142 that includes data and high level commands (e.g., place a Helvetica 12 point letter “Q” at location x,y on the page). Computer 102 transfers description file 142 to printer 120 via communication link 118 , and printer 120 stores file 142 in memory 128 .
Processor 122 then renders description file 142 into image data 114 , including performing a dual halftone process as described in further detail below with reference to FIGS. 2-5 . In one embodiment, printer 120 includes PCL firmware for rendering the description file 142 into image data 114 . Image data 114 is stored in memory 128 of printer 120 , where it is retrieved and processed by laser print engine 130 and printed to a medium.
FIG. 2 is an image illustrating one embodiment of a 50% gray scale magnified letter “H” 112 a . Magnified letter “H” 112 a is a portion of data 112 to be printed. Magnified letter “H” 112 a is rendered by processor 104 or processor 122 into image data 114 .
FIG. 3 is an image illustrating one embodiment of magnified letter “H” 112 a after a digital halftone process has been applied to the image to generate a halftone image 114 a . Each square in halftone image 114 a represents a pixel, as indicated, for example, at 150 . In this embodiment, halftone image 114 a includes 2-bit per pixel data, which results in four possible pixel values. The four possible pixel values include 0 (white), as indicated for example at 152 , 1 (light gray), as indicated for example at 156 , 2 (dark gray), as indicated for example at 158 , and 3 (black), as indicated for example at 154 . The four pixel values indicate the amount of toner applied in each pixel, from white where no toner is applied to the pixel, to black where toner is applied to the entire pixel. The 2-bit per pixel halftone image 114 a approximates the 50% gray scale letter “H” 112 a when the letter “H” is printed at its true size.
The halftone process results in jagged edges, however, as indicated for example at 160 . When halftone image 114 a is printed, the jagged edges make the image look less sharp. The jagged edges are due to the pixel edges having both black and white values and the spacing between the white (or black) pixels. A lower lpi pattern has larger spacing resulting in larger runs of adjacent white pixels and black pixels. The lower lpi pattern also has lower frequency content that the human visual system picks up on more easily than higher frequency content, such as a higher lpi pattern.
FIG. 4 is an image of one embodiment of the magnified letter “H” after a dual digital halftone process has been applied to the image to generate a dual halftone image 114 b . In this embodiment, the edges, indicated for example at 170 , of dual halftone image 114 b do not have 0 (white) pixel values. The absence of 0 (white) pixel values on the edges of dual halftone image 114 b results in sharp edges and prevents the jagged edges illustrated in halftone image 114 a.
The jagged edges are corrected by applying a different halftone to the edges of dual halftone image 114 b , as described in further detail below with reference to FIG. 5 . The interior of dual halftone image 114 b is similar to halftone image 114 a where a single halftone is applied. In this embodiment, halftone image 114 a and the interior of dual halftone image 114 b are halftoned with a 120 lines per inch (lpi) 45° black screen. The edge of dual halftone image 114 b is halftoned with two possible pixel values per edge portion to approximate the edge value of each edge portion.
In one embodiment, the halftone algorithm darkens the edge input slightly and then semi-randomly outputs the two output levels closest to the input percentage. For example, if for the 2-bit per pixel output: 0=0/3 pulse of the laser, 1=1/3 pulse of the laser, 2=2/3 pulse of the laser, and 3=3/3 pulse (or full pulse) of the laser, then for 8-bit per pixel input, an edge value of 128 may be biased to 153. This is approximately 60% of the full pulse value of 255. Therefore, the halftone algorithm attempts to cover on average approximately 60% of the edge. This coverage is obtained by semi-randomly varying the output levels between 1 and 2 (1/3 and 2/3), while biasing toward 2's to get closer to 60%, instead of the 50% that would result if the halftone algorithm evenly alternated between 1 and 2.
By using a gray scale to prevent varying between black and white, the amplitude of modulation is lowered. By semi-randomly varying the output levels, the pattern has significant high frequency content. The combination of the gray scale and the semi-random variation of the output levels results in sharp edges when viewed by the human visual system.
FIG. 5 is a flow diagram illustrating one embodiment of a method 200 for rendering data 112 into image data 114 having dual halftones. Method 200 is performed by processor 104 or processor 122 . At 202 , image processing is started. At 204 , the row (Row) of image data 114 is set equal to one and the column (Col) of image data 114 is set equal to one. At 206 , a window of data is generated around the selected pixel. At 208 , the processor determines whether the selected pixel is an edge pixel. If the selected pixel is not an edge pixel, then at 216 , the output is based on halftone method one (normal halftone). If the selected pixel is an edge pixel, then at 210 , the processor determines if the intensity difference from neighbor pixels outside the edge is greater than 25%, or other suitable value. If the intensity difference from neighbor pixels outside the edge is greater than 25%, or other suitable value, then at 212 , the intensity of the edge pixel is adjusted. If the intensity difference from neighboring pixels from outside the edge is less than 25%, or other suitable value, then at 216 , the output is based on halftone method one (normal halftone).
At 214 , the output is based on halftone method two (alternate halftone) for the edge pixel. At 218 , Col is incremented by one. At 220 , the processor determines if the last column of image data 114 has been processed. If the last column of image data 114 has not been processed, then control returns to block 206 where the next column of image data 114 begins processing. If the last column of image data 114 has been processed, then at 222 , Col is set equal to one and Row is incremented by one. At 224 , the processor determines whether the last row of image data 114 has been processed. If the last row of image data 114 has been processed, then at 226 , processing of image data 114 is completed. If the last row of image data 114 has not been processed, then control returns back to block 206 where the next row of image data 114 begins processing.
In one embodiment, halftone method two (alternate halftone) is any suitable halftone capable of recreating edges that look sharp rather than jagged when printed. Halftone method one (normal halftone), in one embodiment, is any suitable halftone capable of rendering smooth intensity ramps and substantially eliminating banding. In one embodiment, halftone method two (alternate halftone) uses a higher lpi than halftone method one (normal halftone) used for the portions of the image that are not edges. For example, in one embodiment, halftone method one (normal halftone) is a halftone in the 100-150 lpi range, and halftone method two (alternate halftone) is a halftone in the 200-300 lpi range, such as 212 lpi. In other embodiments, other halftones can be used for halftone method one (normal halftone) and halftone method two (alternate halftone).
Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof. | A printing system comprises a memory configured to store image data representing an image. The printing system comprises a processor configured to perform a first digital halftone process on a first portion of the image and a second digital halftone process on a second portion of the image. | 6 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 12/329,509, filed Dec. 5, 2008, which is a divisional of U.S. application Ser. No. 10/630,249, filed Jul. 30, 2003, now U.S. Pat. No. 7,511,339, which is a continuation of U.S. application Ser. No. 10/155,554, filed May 24, 2002, now U.S. Pat. No. 6,710,406, which is a continuation of U.S. application Ser. No. 08/970,221, filed Nov. 14, 1997, now U.S. Pat. No. 6,429,481, all of which are incorporated herein by reference in their entirety for all purposes.
BACKGROUND OF THE INVENTION
The present invention relates to field effect transistors, in particular trench DMOS transistors, and methods of their manufacture.
Power field effect transistors, e.g., MOSFETs (metal oxide semiconductor field effect transistors), are well known in the semiconductor industry. One type of MOSFET is a DMOS (double diffused metal oxide semiconductor) transistor. DMOS transistors typically include a substrate on which an epitaxial layer is grown, a doped source junction, a doped heavy body, a doped well of the same (p or n) doping as the heavy body, and a gate electrode. In trenched DMOS transistors the gate electrode is a vertical trench. The heavy body is typically diffused deeper than the bottom of the trench, to minimize electric field at the bottom corners of the trench and thereby prevent avalanche breakdown from damaging the device. The trench is filled with conductive polysilicon, and the polysilicon is generally overetched, to assure that it is completely removed from the surface surrounding the trench. This overetching generally leaves a recess between the top of the polysilicon and the surface of the semiconductor substrate (i.e., the surface of the epitaxial layer). The depth of this recess must be carefully controlled so that it is shallower than the depth of the source junctions. If the recess is deeper than the source junctions the source may miss the gate, resulting in high on-state resistance, high threshold, and potentially a non-functional transistor.
The source and drain junctions can be doped with either p-type or n-type dopants; in either case, the body will be doped with the opposite dopant, e.g., for n-type source and drain the body will be p-type. DMOS transistors in which the source and drain are doped with p-type carriers are referred to as “p-channel”. In p-channel DMOS transistors a negative voltage applied to the transistor gate causes current flow from the source region, through a channel region of the body, an accumulation region of the epitaxial layer, and the substrate, to the drain region. Conversely, DMOS transistors, in which the source and drain are doped with n-type carriers, are referred to as “n-channel”. In n-channel DMOS transistors a positive voltage applied to the transistor gate causes current to flow from drain to source.
It is desirable that DMOS transistors have low source to drain resistance (Rds on ) when turned on and low parasitic capacitance. The transistor structure should also avoid “punchthrough”. Punchthrough occurs when, upon application of a high drain to source voltage, depletion into the body region extends to the source region, forming an undesirable conductive path through the body region when the transistor should be off. Finally, the transistor should have good “ruggedness”, i.e., a high activation current is needed to turn on the parasitic transistor that inherently exists in DMOS transistors.
Generally a large number of MOSFET cells are connected in parallel forming a single transistor. The cells may be arranged in a “closed cell” configuration, in which the trenches are laid out in a grid pattern and the cells are enclosed on all sides by trench walls. Alternatively, the cells may be arranged in an “open cell” configuration, in which the trenches are laid out in a “stripe” pattern and the cells are only enclosed on two sides by trench walls. Electric field termination techniques are used to terminate junctions (doped regions) at the periphery (edges) of the silicon die on which the transistors are formed. This tends to cause the breakdown voltage to be higher than it would otherwise be if controlled only by the features of the active transistor cells in the central portions of the die.
SUMMARY OF THE INVENTION
The present invention provides field effect transistors that have an open cell layout that provides good uniformity and high cell density and that is readily scalable. Preferred trenched DMOS transistors exhibit low Rds on , low parasitic capacitance, excellent reliability, resistance to avalanche breakdown degradation, and ruggedness. Preferred devices also include a field termination that enhances resistance to avalanche breakdown. The invention also features a method of making trench DMOS transistors.
In one aspect, the invention features a trenched field effect transistor that includes (a) a semiconductor substrate, (b) a trench extending a predetermined depth into the semiconductor substrate, (c) a pair of doped source junctions, positioned on opposite sides of the trench, (d) a doped heavy body positioned adjacent each source junction on the opposite side of the source junction from the trench, the deepest portion of the heavy body extending less deeply into said semiconductor substrate than the predetermined depth of the trench, and (e) a doped well surrounding the heavy body beneath the heavy body.
Preferred embodiments include one or more of the following features. The doped well has a substantially flat bottom. The depth of the heavy body region relative to the depths of the well and the trench is selected so that the peak electric field, when voltage is applied to the transistor, will be spaced from the trench. The doped well has a depth less than the predetermined depth of the trench. The trench has rounded top and bottom corners. There is an abrupt junction at the interface between the heavy body and the well, to cause the peak electric field, when voltage is applied to the transistor, to occur in the area of the interface.
In another aspect, the invention features an array of transistor cells. The array includes (a) a semiconductor substrate, (b) a plurality of gate-forming trenches arranged substantially parallel to each other and extending in a first direction, the space between adjacent trenches defining a contact area, each trench extending a predetermined depth into said substrate, the predetermined depth being substantially the same for all of said gate-forming trenches; (c) surrounding each trench, a pair of doped source junctions, positioned on opposite sides of the trench and extending along the length of the trench, (d) positioned between each pair of gate-forming trenches, a doped heavy body positioned adjacent each source junction, the deepest portion of each said heavy body extending less deeply into said semiconductor substrate than said predetermined depth of said trenches, (e) a doped well surrounding each heavy body beneath the heavy body; and (f) p+ and n+ contacts disposed at the surface of the semiconductor substrate and arranged in alternation along the length of the contact area.
Preferred embodiments include one or more of the following features. The first and second dopants both comprise boron. The first energy is from about 150 to 200 keV. The first dosage is from about 1E15 to 5E15 cm −2 . The second energy is from about 20 to 40 keV. The second dosage is from about 1E14 to 1E15 cm −2 .
In yet another aspect, the invention features a semiconductor die that includes (a) a plurality of DMOS transistor cells arranged in an array on a semiconductor substrate, each DMOS transistor cell including a gate-forming trench, each of said gate-forming trenches having a predetermined depth, the depth of all of the gate-forming trenches being substantially the same; and (b) surrounding the periphery of the array, a field termination structure that extends into the semiconductor substrate to a depth that is deeper than said predetermined depth of said gate-forming trenches.
Preferred embodiments include one or more of the following features. The field termination structure includes a doped well. The field termination structure includes a termination trench. The field termination structure includes a plurality of concentrically arranged termination trenches. Each of the DMOS transistor cells further comprises a doped heavy body and the doped heavy body extends into the semiconductor substrate to a depth than is less than the predetermined depth of the gate-forming trenches.
The invention also features a method of making a heavy body structure for a trenched DMOS transistor including (a) providing a semiconductor substrate; (b) implanting into a region of the substrate a first dopant at a first energy and dosage; and (c) subsequently implanting into said region a second dopant at a second energy and dosage, said second energy and dosage being relatively less than said first energy and dosage.
Preferred embodiments include one or more of the following features. The first and second dopants both comprise boron. The first energy is from about 150 to 200 keV. The first dosage is from about 1E15 to 5E15. The second energy is from about 20 to 40 keV. The second dosage is from about 1E14 to 1E15.
Additionally, the invention features a method of making a source for a trenched DMOS transistor including (a) providing a semiconductor substrate; (b) implanting into a region of the substrate a first dopant at a first energy and dosage; and (c) subsequently implanting into the region a second dopant at a second energy and dosage, the second energy and dosage being relatively less than the first energy and dosage.
Preferred embodiments include one or more of the following features. The first dopant comprises arsenic and the second dopant comprises phosphorus. The first energy is from about 80 to 120 keV. The first dosage is from about 5E15 to 1E16 cm −2 . The second energy is from about 40 to 70 keV. The second dosage is from about 1E15 to 5E15 cm −2 . The resulting depth of the source is from about 0.4 to 0.8 m the finished DMOS transistor.
In another aspect, the invention features a method of manufacturing a trenched field effect transistor. The method includes (a) forming a field termination junction around the perimeter of a semiconductor substrate, (b) forming an epitaxial layer on the semiconductor substrate, (c) patterning and etching a plurality of trenches into the epitaxial layer; (d) depositing polysilicon to fill the trenches, (e) doping the polysilicon with a dopant of a first type, (f) patterning the substrate and implanting a dopant of a second, opposite type to form a plurality of wells interposed between adjacent trenches, (g) patterning the substrate and implanting a dopant of the second type to form a plurality of second dopant type contact areas and a plurality of heavy bodies positioned above the wells, each heavy body having an abrupt junction with the corresponding well, (h) patterning the substrate and implanting a dopant of the first type to provide source regions and first dopant type contact areas; and (i) applying a dielectric to the surface of the semiconductor substrate and patterning the dielectric to expose electrical contact areas.
Other features and advantages of the invention will be apparent from the following detailed description, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a highly enlarged, schematic perspective cross-sectional view showing a portion of a cell array including a plurality of DMOS transistors according to one aspect of the invention. The source metal layer and a portion of the dielectric layer have been omitted to show the underlying layers. FIGS. 1A and 1B are side cross-sectional views of a single line of transistors from the array of FIG. 1 , taken along lines A-A and B-B, respectively. In FIGS. 1A and 1B the source metal and dielectric layers are shown.
FIG. 2A is a highly enlarged schematic side cross-sectional view of a semiconductor die showing a portion of the cell array and the field termination.
FIG. 2B is a cross-sectional view of another embodiment of a semiconductor die showing a portion of the cell array and the field termination.
FIG. 3 is a flow diagram showing the photo mask sequence of a preferred process for forming a trench DMOS transistor of FIG. 1 .
FIGS. 4-4K are schematic side cross-sectional views showing the individual steps of the process diagrammed in FIG. 3 . The figure numbers for the detailed views in FIGS. 4-4K are shown parenthetically under the corresponding diagram boxes in FIG. 3 .
FIGS. 5 , 5 A and 5 B are spreading resistance profile graphs, reflecting the dopant concentration at different regions of the transistor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A cell array 10 , including a plurality of rows 12 of trenched DMOS transistors, is shown in FIG. 1 . Cell array 10 has an open cell configuration, i.e., trenches 14 run in only one direction, rather than forming a grid. Individual cells are formed by alternating n+ source contacts 16 and p+ contacts 18 in rows 20 that run parallel to and between trenches 14 . The configuration of the regions of each row that have an n+ source contact are shown in cross-section in FIG. 1A , while the regions that have a p+ contact are shown in FIG. 1B .
As shown in FIGS. 1A and 1B , each trenched DMOS transistor includes a doped n+ substrate (drain) layer 22 , a more lightly doped n-epitaxial layer 24 , and a gate electrode 28 . Gate electrode 28 comprises a conductive polysilicon that fills a trench 14 . A gate oxide 26 coats the walls of the trench and underlies the polysilicon. The top surface of the polysilicon is recessed from the surface 30 of the semiconductor substrate by a distance R (typically from about 0 to 0.4 μm). N+ doped source regions 32 a , 32 b are positioned one on each side of the trench 14 . A dielectric layer 35 covers the trench opening and the two source regions 32 a , 32 b . Extending between the source regions of adjacent cells is a p+ heavy body region 34 and, beneath it, a flat-bottomed p− well 36 . In the areas of the cell array which have a n+ contact 16 , a shallow n+ doped contact region extends between the n+ source regions. A source metal layer 38 covers the surface of the cell array.
The transistor shown in FIGS. 1A and 1B includes several features that enhance the ruggedness of the transistor and its resistance to avalanche breakdown degradation.
First, the depth of the p+ heavy body region 34 relative to the depths of the trench 14 and the flat bottom of the p− well is selected so that the peak electric field when voltage is applied to the transistor will be approximately halfway between adjacent trenches. The preferred relative depths of the p+ heavy body, the p− well and the trench are different for different device layouts. However, preferred relative depths can be readily determined empirically (by observing the location of peak electric field) or by finite element analysis.
Second, the bottom corners of the trench 14 are rounded (preferably, the top corners are also rounded; this feature is not shown). Corner rounding can be achieved using the process described in U.S. application Ser. No. 08/959,197, filed on Oct. 28, 1997, now U.S. Pat. No. 6,103,635. The rounded corners of the trench also tend to cause the peak electric field to be moved away from the trench corners and towards a central location between adjacent trenches.
Third, an abrupt junction at the interface between the p+ heavy body and the p− well causes the peak electric field to occur in that area of the interface. Avalanche multiplication initiates at the location of the peak electric field, thus steering hot carriers away from the sensitive gate oxide and channel regions. As a result, this structure improves reliability and avalanche ruggedness without sacrificing cell density as much as a deeper heavy body junction. This abrupt junction can be achieved by the double doping process that will be described below, or by other processes for forming abrupt junctions, many of which are known in the semiconductor field.
Lastly, referring to FIG. 2A , the cell array is surrounded by a field termination junction 40 which increases the breakdown voltage of the device and thaws avalanche current away from the cell array to the periphery of the die. Field termination junction 40 is a deep p+ well, preferably from about 1 to 3 μm deep at its deepest point, that is deeper than the p+ heavy body regions 34 in order to reduce the electric field caused by the junction curvature. A preferred process for making the above-described transistors is shown as a flow diagram in FIG. 3 , and the individual steps are shown schematically in FIGS. 4-4K . It is noted that some steps that are conventional or do not require illustration are described below but not shown in FIGS. 4-4K . As indicated by the arrows in FIG. 3 , and as will be discussed below, the order of the steps shown in FIGS. 4-4K can be varied. Moreover, some of the steps shown in FIGS. 4-4K are optional, as will be discussed.
A semiconductor substrate is initially provided. Preferably, the substrate is a N++ Si substrate, having a standard thickness, e.g., 500 μm, and a very low resistivity, e.g., 0.001 to 0.005 Ohm-cm. An epitaxial layer is deposited onto this substrate, as is well known, preferably to a thickness of from about 4 to 10 μm. Preferably the resistivity of the epitaxial layer is from about 0.1 to 3.0 Ohm-cm.
Next, the field termination junction 40 is formed by the steps shown in FIGS. 4-4C . In FIG. 4 , an oxide layer is formed on the surface of the epitaxial layer. Preferably, the thickness of the oxide is from about 5 to 10 kÅ. Next, as shown in FIG. 4A , the oxide layer is patterned and etched to define a mask, and the p+ dopant is introduced to form the deep p+ well field termination. A suitable dopant is boron, implanted at an energy of from about 40 to 100 keV and a dose of 1E14 (1×10 14 ) to 1E16 cm −2 . As shown in FIG. 4B , the p+ dopant is then driven further into the substrate, e.g., by diffusion, and a field oxide layer is formed over the p+ junction. Preferably the oxide thickness is from about 4 to 10 kÅ. Finally, the oxide ( FIG. 4 ) over the active area of the substrate (the area where the cell array will be formed) is patterned and removed by any suitable etching process, leaving only the field oxide in suitable areas. This leaves the substrate ready for the following steps that will form the cell array.
It is noted that, as an alternative to steps 4 - 4 C, a suitable field termination structure can be formed using a ring-shaped trench which surrounds the periphery of the cell array and acts to lessen the electric field and increase the resistance to avalanche breakdown degradation. This trench field termination does not require a field oxide or deep p+ body junction to be effective. Consequently, it can be used to reduce the number of process steps. Using a trench ring (or multiple concentric trench rings) to form a field termination is described in, e.g., U.S. Pat. No. 5,430,324, the full disclosure of which is hereby incorporated herein by reference. Preferably, the trench would have substantially the same depth as the trenches in the cell array. An exemplary embodiment for a trench termination structure is shown in FIG. 2B . Termination trenches 40 T form concentric rings around the edge of the device. Termination trenches 40 T can be filled with either floating conductive material such as polysilicon or floating dielectric material such as silicon dioxide. Also, the p-type well regions on either sides of termination trenches 40 T can be made either shallower than the trenches or deeper than the trenches.
The cell array is formed by the steps shown in FIGS. 4D-4K . First, a plurality of trenches are patterned and etched into the epitaxial layer of the substrate ( FIG. 4D ). Preferably, as noted above, the trenches are formed using the process U.S. application Ser. No. 08/959,197, filed on Oct. 28, 1997, now U.S. Pat. No. 6,103,635, so that the upper and lower corners of each trench will be smoothly rounded. As shown in FIG. 1 and described above, the trenches are patterned to run in only one direction, defined as an open cell structure. After trench formation, a gate oxide layer is formed on the trench walls, as is well known in the semiconductor field. Preferably the gate oxide has a thickness of from about 100 to 800 Å.
Next, as shown in FIG. 4E , polysilicon is deposited to fill the trench and cover the surface of the substrate, generally to a thickness of from about 1 to 2 μm depending on the trench width (shown by the dotted lines in FIG. 4E ). This layer is then planarized by the nature of its thickness relative to the trench width, typically from about 2 to 5 kÅ (indicated by solid lines in FIG. 4E ). The polysilicon is then doped to n-type, e.g., by conventional POCL 3 doping or by phosphorus implant. The backside of the wafer need not be stripped (as is conventionally done prior to doping the polysilicon to enhance defect gettering) because any further doping of the highly doped substrate would be unlikely to result in any enhancement in defect gettering.
The polysilicon is then patterned with a photoresist mask and etched to remove it from the trench areas, as shown in FIG. 4F . A small recess between the top of the polysilicon in the trench and the substrate surface inherently results when the polysilicon is etched completely to remove all of the polysilicon from the substrate surface. The depth of this recess must be controlled so that it does not exceed the depth of the n+ source junction that will be formed in a later step. To reduce the need to carefully control this aspect of the process, a relatively deep n+ source junction is formed, as will be discussed below.
Then, as shown in FIG. 4G , the p− well is formed by implanting the dopant, e.g., a boron implant at an energy of 30 to 100 keV and a dosage of 1E13 to 1E15, and driving it in to a depth of from about 1 to 3 μm using conventional drive in techniques.
The next two steps (p+ heavy body formation) can be performed either before formation of the n+ source junction, or afterwards, as indicated by the arrows in FIG. 3 . P+ heavy body formation and n+ source junction formation can be performed in either order because they are both resist-masked steps and because there is no diffusion step in between. This advantageously allows significant process flexibility. The p+ heavy body formation steps will be described below as being performed prior to source formation; it will be understood that n+ source formation could be performed first simply by changing the order of the steps discussed below.
First, a mask is formed over the areas that will not be doped to p+, as shown in FIG. 4H . (It is noted that this masking step is not required if the p+ heavy body is formed later, after the dielectric layer has been applied and patterned for contact holes, see FIG. 4K , below, so that the dielectric itself provides a mask.) As discussed above, it is preferred that the junction at the interface between the p− well and the p+ heavy body be abrupt. To accomplish this, a double implant of dopant (e.g., boron) is performed. For example, a preferred double implant is a first boron implant at an energy of 150 to 200 keV and a dose of 1E15 to 5E15 cm −2 , and a second boron implant at an energy of 20 to 40 keV and a dose of 1E14 to 1E15 cm −2 . The high energy first implant brings the p+ heavy body as deep as possible into the substrate, so that it will not compensate the n+ source junction to be introduced later. The second, lower energy/lower dose implant extends the p+ heavy body from the deep region formed during the first implant up to the substrate surface to provide the p+ contact 18 . The resulting p+ heavy body junction is preferably about 0.4 to 1 m deep at this stage of the process (final junction depth after drive-in is preferably about 0.5 to 1.5 m deep), and includes a region of high dopant concentration near the interface with the p− well, and a region of relatively low dopant concentration at the contact surface of the p+ heavy body. A preferred concentration distribution is shown in FIG. 5 .
It will be appreciated by those skilled in the art that the abrupt junction can be formed in many other ways, e.g., by diffused dopants, by using a continuous dopant source at the surface or by using atoms that diffuse slowly.
After the formation of the p+ heavy body, a conventional resist strip process is performed to remove the mask, and a new mask is patterned to prepare the substrate for the formation of the n+ source junction. This mask is a n+ blocking mask and is patterned to cover the areas of the substrate surface which are to provide p+ contacts 18 ( FIGS. 1 and 1B ), as shown in FIG. 4I . This results in the formation of alternating p+ and n+ contacts after n-type doping (see lines A-A and B-B and cross-sectional views A-A and B-B in FIG. 4I , which correspond to FIGS. 1A and 1B ).
The n+ source regions and n+ contact are then formed using a double implant. For example, a preferred double implant process is a first implant of arsenic at an energy of 80 to 120 keV and a dose of 5E15 to 1E16 cm −2 followed by a second implant of phosphorus at an energy of 40 to 70 keV and a dose of 1E15 to 5E15 cm −2 . The phosphorus implant forms a relatively deep n+ source junction, which allows more process flexibility in the depth of the polysilicon recess, as discussed above. Phosphorus ions will penetrate deeper into the substrate during implant and also during later diffusion steps. Advantageously, the n+ source regions will have a depth of about 0.4 to 0.8 m after diffusion. The arsenic implant extends the n+ source to the substrate surface, and also forms the n+ contacts 16 (see FIGS. 1 and 1A ) by compensating (converting) the p-type surface of the p+ heavy body to n-type in the desired contact area. The preferred sheet resistance profiles for the n+ source along the edge of the trench, and the n+ contact are shown in FIGS. 5A and 5B , respectively.
Thus, the alternating p+ and n+ contacts 18 , 16 , shown in FIG. 1 are formed by patterning the substrate with appropriate masks and doping with the first p+ implant and the second n+ implant, respectively, as described above. This manner of forming the alternating contacts advantageously allows an open cell array having a smaller cell pitch than is typical for such arrays and thus a higher cell density and lower Rds on .
Next, a conventional n+ drive is performed to activate the dopants. A short cycle is used, preferably 10 min at 900° C., so that activation occurs without excessive diffusion.
A dielectric material, e.g., borophosphate silicate glass (BPSG), is then deposited over the entire substrate surface and flowed in a conventional manner ( FIG. 4J ), after which the dielectric is patterned and etched ( FIG. 4K ) to define electrical contact openings over the n+ and p+ contacts 16 , 18 .
As noted above, the p+ heavy body implant steps can be performed at this point, if desired (rather than prior to n+ source formation), eliminating the need for a mask and thus reducing cost and process time.
Next, the dielectric is reflowed in an inert gas, e.g., a nitrogen purge. If the p+ body has been implanted immediately prior, this step is required to activate the p+ dopant. If the p+ body was implanted earlier, prior to the n+ drive, this step can be omitted if the dielectric surface is sufficiently smooth-edged around the contact openings.
The cell array is then completed by conventional metalization, passivation deposition and alloy steps, as is well known in the semiconductor field.
Other embodiments are within the claims. For example, while the description above is of an n-channel transistor, the processes of the invention could also be used to form a p-channel transistor. To accomplish this, “p” and “n” would simply be reversed in the above description, i.e., where “p” doping is specified above the region would be “if” doped instead, and vice versa. | A trenched field effect transistor is provided that includes (a) a semiconductor substrate, (b) a trench extending a predetermined depth into the semiconductor substrate, (c) a pair of doped source junctions, positioned on opposite sides of the trench, (d) a doped heavy body positioned adjacent each source junction on the opposite side of the source junction from the trench, the deepest portion of the heavy body extending less deeply into said semiconductor substrate than the predetermined depth of the trench, and (e) a doped well surrounding the heavy body beneath the heavy body. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to methods for producing iron oxide particles in a solid non-magnetic matrix by rapid solidification of an iron oxide precursor mixed with a non-magnetic matrix material.
Oxide particles for magnetic recording purposes are currently synthesized using a very complex and lengthy procedure. This procedure requires the precipitation of synthetic α-(FeO)OH(goethite) from aqueous solutions, the dehydration of α-Fe 2 O 3 to Fe 3 O 4 , and finally the careful oxidation of Fe 2 O 4 , to form γ-Fe 2 O 3 . (Akashi, Ferrites: Proceedings of the International Conference, Sept.-Oct. 1980 Japan p. 548-552).
Another wet chemistry technique for preparation of iron oxide (spinel ferrite) powders consists of precipitation of the spinel ferrite from aqueous solutions containing ferrous ions and other divalent metallic ions. The solution pH is controlled formed by oxidation of the aqueous solution in air above 50° C. (Takada, Ferrites: Proceedings of the International Conference. Sept.-Oct., 1980, Japan, p. 3-6).
Another wet chemical method for synthesis of iron oxide powders involves the reduction of ferrous ions with sodium borohydride, a very expensive reducing agent, in the presence of a magnetic field (Akashi, Ferrites: Proceedings of the International Conference, Sept.-Oct., 1980, Japan, p. 548-552).
It is also possible to prepare cobalt-ferrite iron oxide powders using wet chemistry methods. According to one such method, acicular γ-Fe 2 O 3 particles are suspended in an alkaline solution containing Co 2+ and then treated at 90° C. for 10 hours (Hayama, Ferrites: Proceedings of the International Conference, Sept.-Oct., 1980, Japan, p. 521-525).
Alternative preparation methods for iron oxide powders include condensation of vaporized metal in a low pressure inert gas atmosphere in the presence of a magnetic field. Powders produced in this manner exhibit low noise levels and excellent stability against oxidation; however, this method is extremely expensive (Akashi, Ferrites: Proceedings of the International Conference, Sept.-Oct., 1980, Japan, p. 548-552).
Cobalt modified iron oxides may be prepared using pyrolytic decomposition (chemical vapor deposition) of cobalt-acetylacetonate vapor on the surface of iron oxide fluidized acicular particles. Powders prepared using this process are suitable for magnetic recording applications. They exhibit high coercivities (550-600 Oe) at relatively low Co 2+ (2-3) and Fe 2+ (8-9) wt % (Monteil et al. Ferrites: Proceedings of the International Conference, Sept.-Oct., 1980, Japan, p. 532-536).
Complex oxides for ferrites, consisting of iron oxide and zinc oxide, are prepared by spraying aqueous chloride solutions of the respective oxide metallic constituents onto a fluidized roasting furnace (Hirai et al. WO88-00925).
The iron oxide and doped iron oxide particles produced according to these methods are incorporated into magnetic discs, tapes and other devices for magnetic recording. Such magnetic recording media usually consist of a non-magnetic support for a magnetic recording layer of ferromagnetic powder (i.e. iron oxide or doped iron oxide) dispersed in an organic binder material (Saito et al., U.S. Pat. No. 4,820,581, JP 62125533, JP 57078631, JP 62241134, JP 62162228, and Funahashi et al. U.S. Pat. No. 4,820,565) where the non-magnetic support or substrate may be a polyester film or tape.
Efforts have also been directed towards improvement of durability of magnetic recording media. One approach involves the combination of cobalt doped γ-Fe 2 O 3 and Cr 2 O 3 with non-magnetic α-iron oxide in an organic binder by ball milling subsequent coating of a PET film (JP 55129935).
Other approaches coat the magnetic iron oxide particles with a layer of silica (SiO 2 ) by sputtering (JP 58006528) or by immersing the metal oxide particle in a ph-controlled suspension with an amorphous, powdered silicate which is subsequently made crystalline by adjustment of the suspension ph. An alumina (Al 2 O 3 ) protective coating may also be e-beam deposited on the surface of magnetic iron oxide particles (JP 58006528). A non-magnetic zinc oxide (ZnO) protective coating has also been electro-deposited on a magnetic iron oxide layer which had previously been electro-deposited on an aluminum or aluminum alloy substrate (JP 621255126).
Glass-forming additives such as B 2 O 3 , Bi 2 O 3 , P 2 O 5 , MoO 3 and V 2 O 5 have been used in the solid state reaction of α-FeOOH particles and colloidal BaCo 3 or SrCO 3 .
Addition of approximately 0.5 wt % B 2 O 3 best accelerated ferrite formation without adhesion of particles, resulting in thin-plate hexagonal ferrites with good magnetic recording properties (Sugimoto, Fourth International Conference on Ferrites, Part 2, Oct.-Nov. 1984, San Francisco, Calif., U.S.A. p. 273-279).
Amorphous cobalt ferrite (CoFe 2 O 4 ) films have also been prepared using a two-source vacuum evaporation technique with CoFe 2 alloy and P 2 O 5 as the source materials. These amorphous cobalt ferrite films display high perpendicular anisotropy (Hiratsuka et al., Electronics and Communications in Japan, Part 2, 71, 95-102 (1988) and IEEE Transactions on Magnetics, MAG-23, 3326-3328 (1987)).
Japanese patent, JP 61080618, also describes sputtering of Co-γ-Fe 2 O 3 on a non-magnetic disc substrate. Japanese patent, JP 62095735, describes a process for conversion of sputtered α-Fe 2 O 3 to Fe 3 O 4 on a non-magnetic substrate such as a drum or disc, using laser beam irradiation.
Methods exist for precipitation or nucleation of magnetic crystallites in glassy matrices.
U.S. Pat. No. 4,083,727 to Andrus et al. discloses a method for production of glass-ceramic articles having integral magnetic magnetite (Fe 3 O 4 ) crystals. According to this method, a Li 2 O--FeO--Al 2 O 3 --SiO 2 glass article nucleated with TiO 2 is heat-treated to induce crystalline nucleation within the article body, resulting in a glass-ceramic article which is subsequently exposed to a reducting atmosphere to convert hematite crystals in its surface layer to magnetite, yielding films with high coercivities and saturation magnetizations which compare favorably to those of magnetite and other ceramic ferrite materials. The magnetic recording medium disclosed in JP 62042315 consists of a layered structure, one layer of which is a magnetic recording medium made from α-FeO 2 O 3 , Al 2 O 3 , SiO 2 , B 2 O 3 or Co 3 O 4 .
The nucleation of inhomogeneous precipitates having ferrimagnetic cores within antiferromagnetic skins has been observed in B 2 O 3 --BaO--Fe 2 O 3 glass matrices prepared by slow quenching between stainless steel slabs (Fahmy et al., Physics And Chemistry Of Glasses, 13, 21-26 (1972) and MacCrone, in Amorphous Magnetism, H. O. Hooper and A. M. deGraaf, eds., Plenum Press, New York-London 1973 p. 77).
Magnetic phases have been precipitated in Li 2 B 2 O 4 --LiFe 5 O 8 glass systems prepared by splat quenching, roller quenching and gun quenching techniques (Chaumont et al., Mat. Res. Bull. 15, 771-776 (1980); Chaumont et al., Rapidly Quenched Metals III, Third International Conference, University of Sussex, Brighton, July 1978 p. 401; Chaumont et al., Rev. Int. Htes. Temp. et Refract. 15, 23-32 (1978)).
Partially recrystallized glasses in the Li 2 O--Fe 2 O 3 SiO 2 system, prepared by slow quenching between steel plates exhibit some ferrimagnetic properties at high Fe 2 O 3 contents (Weaver et al., American Ceramic Society Bulletin 52, 467-472 (1973)).
Ferrimagnetic amorphous cobalt ferrites have been prepared by rapid quenching to liquid nitrogen temperatures of cobalt ferrite combined with P 2 O 5 glass network former (Sugimoto et al., Jpn. J. Apl. Phys. 21, 197-198 (1982)).
Splat quenching techniques have been applied to the BaO--Fe 2 O 3 and SrO--Fe 2 O 3 systems where BaFe 12 O 19 crystals have been observed along with weak ferromagnetism in the glass matrix (Monteil et al., Mat. Res. Bull. 12, 235-240 (1977); Monteil et al., Journal of Solid State Chemistry, 25, 1-8 (1978); Chaumont et al., Mat. Res. Bull. 15, 771-776 (1980); Chaumont et al., Rapidly Quenched Metals III, Third International Conference, University of Sussex, Brighton, July 1978 p. 401; Chaumont et al., Rev. Int. Htes. Temp. et Refract. 15, 23-32 (1978)).
SUMMARY OF THE INVENTION
According to one aspect of the invention, the simplified method for producing iron oxide containing magnetic oxide precipitates embedded in a non-magnetic matrix includes forming a mixture including at least one iron oxide precursor and a non-magnetic matrix material. This mixture is vaporized or melted and then subjected to rapid heat removal, by either condensation from the vapor in sputtering processes or rapid solidification in quenching from a melt. Such materials are well suited for applications in magnetic recording media and other magnetic components.
In one embodiment, rapid heat removal occurs by rapid solidification specifically by a double-roller quenching technique where the cooling rate is greater than 10 3 K per second and is preferably in the range 10 5 -10 6 K per second. The mixture may be made by comminuting the iron oxide precursor and matrix material to form a powder and then pressing and sintering the powder before it is melted and rapidly solidified. The mixture can include α-Fe 2 O 3 and SiO 2 Other glass network formers such as B 2 O 3 , P 2 O 5 , GeO 2 , As 2 O 5 , Sb 2 O 5 or Zr 2 O 5 can be matrix materials.
In another embodiment, an oxide such as Fe 3 O 4 and a matrix material such as SiO 2 are ball-milled in acetone, dried, pressed into rods, and sintered in flowing 02 to produce the starting mixture. CoO or other transition metal oxides such as Sc 2 O 3 , TiO 2 , V 2 O 5 , CrO 3 , MnO 7 , NiO, CuO or ZnO or rare earth oxides may also be included in the mixture.
In another embodiment, thin film cobalt ferrite within a glass former matrix may be sputtered so that the film material rapidly condenses from the vapor phase at heat removal rates of typically 10 12 °/second, rates much greater than those possible by rapid solidification from a liquid melt.
According to another aspect of the invention, iron oxide containing magnetic oxide powder is produced by forming a mixture which includes at least one iron oxide and a matrix material. This mixture is melted and then rapidly solidified to form an iron oxide/matrix solid. The matrix material is then removed and the iron oxide containing magnetic oxide powder is collected.
The oxide precipitates collected after rapid solidification and subsequent removal of the non-magnetic matrix material are equiaxed, isotropic particles of γ-Fe 2 O 3 .
According to another aspect of the invention, a shaped recording medium may be fabricated from magnetic oxide precipitates embedded in a non-magnetic matrix. The magnetic oxide precipitate containing iron oxide embedded in a non-magnetic matrix flakes can be crushed to a size suitable for powder processing and subsequently formed into thick self-supporting shaped articles which are sintered to yield magnetic recording media.
Alternatively, according to another aspect of the invention, shaped recording media are produced by removing the magnetic oxide containing iron oxide precipitates from the non-magnetic matrix and mixing them with binders and elastomers to make an unsintered sheet which can then be applied to a substrate. Such a structure can then be sintered to yield a thick recording film having the shape of the supporting substrate.
The magnetic oxide precipitates made according to the methods of the invention exhibit superior magnetic properties excellently suited for magnetic recording applications or fabrication of ferrite magnetic recording heads. In particular, the material consists of densely-packed, isolated individual Particles that do not clump, permitting high-density information storage. The materials are magnetically isotropic and are thus easy to align. Further, the material exhibits a narrow distribution of particle sizes which results in a high signal-to-noise ratio in a magnetic recording application.
The magnetic oxide Precipitates produced according to the methods of the invention may be removed from the non-magnetic matrix material by dissolution or crushing. They are collected and incorporated into conventional binders such as organic compounds for application to appropriately shaped substrates in fabrication of magnetic tapes, hard disks, floppy disks or drums usable for double sided recording.
The method of the present invention represents a major simplification over conventional methods for making iron oxide powders or shaped articles for magnetic recording purposes. The method is a relatively easily-controlled process with fewer steps than the presently known procedure. The raw materials are inexpensive and readily available. Further, the method is flexible, allowing the addition of transition metal elements such as cobalt or chromium, and rare earth elements.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic illustration of the double-roller rapid solidification method utilized in the practice of the invention;
FIG. 2 is an SEM micrograph at 22,000× magnification of Fe 2 O 3 --Fe 3 O 4 crystallites growing from glassy strands produced from a starting composition of 82 wt % Fe 3 O 4 +SiO 2 prepared according to the method of the invention; and
FIG. 3 is an SEM micrograph at 80,000× magnification of the same material as shown in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
EXAMPLE 1
The samples used in the double roller quenching process to produce crystallites were made from powder mixtures that had been ball-milled for approximately eight hours in acetone, dried, and pressed into rods. These rods had a diameter of 5/8 inch and had lengths that varied from 1.5 to 2 inches. The resulting rods were sintered under flowing oxygen for a period of approximately five hours. The starting powder compositions are listed below in Table I along with the sintering temperatures and the phases present after sintering.
TABLE I______________________________________Initial Sintering Phases PresentComposition Temperature After Sintering______________________________________82 wt % Fe.sub.3 O.sub.4 + 1435° C. α - Fe.sub.2 O.sub.3 + Fe.sub.3 O.sub.4 +18 wt % SiO.sub.2 cristobalite77 wt % Fe.sub.3 O.sub.4 + 950° C. α - Fe.sub.2 O.sub.3 + SiO.sub.2 +18 wt % SiO.sub.2 + Fe.sub.3 O.sub.45 wt % CoO46 wt % Fe.sub.3 O.sub.4 + 950° C. CoFe.sub.2 O.sub.4 + (Co,Fe).sub.2 O.sub.3 +26 wt % SiO.sub.2 + glass28 wt % CoO______________________________________
It should be noted that the present invention can also be used to produce the magnetic precipitates directly from a starting mixture of α-Fe 2 O 3 and SiO 2 .
The method according to the invention is illustrated in FIG. 1. Rod 10 of sintered precursor material was suspended above tool-steel rollers 12 that were held against one another by spring loaded bearings (not shown). The distance from the bottom of rod 10 to the rollers' surface was 10 centimeters. Rollers 12 were 10 centimeters in length and 5.5 centimeters in diameter and had a maximum rotation rate of 6,000 rpm in the direction given by arrows 15. Suspended rod 10 was melted in air using H 2 --O 2 torches 13. Drops melted from rod 10 one-by-one were quenched into flakes as they passed through roller nip 14. Flakes 16 were collected in an aluminum basket 17 placed below rollers 12. Other rapid solidification techniques such as splat quenching, single roller quenching, the gun technique, and melt extraction can be used.
X-ray diffraction studies have been performed on the as-quenched samples. The flakes of the samples that contain zero- and 5-wt % CoO consisted of γ-Fe 2 O 3 , Fe 3 O 4 , or Berthollide oxide. The sample that contained 28 wt % CoO was composed of (Co,Fe)O and (Co,Fe) 2 O 3 . The magnetic properties of the as-quenched flakes are listed below in Table 2. Table 2 also lists two common magnetic recording materials for comparison. Note that the magnetic properties of the sample that included 5 wt % CoO in its starting mixture are comparable to those of currently used magnetic oxide media. Table 2 also lists the average size of the precipitates produced according to the method of the present invention.
TABLE 2______________________________________Sample SpecificStarting Coercivity Magnetization Edge LengthComposition (OE.) (EMU/G) (In A)______________________________________82 wt % Fe.sub.3 O.sub.4 + 240 52 150018 wt % SiO.sub.277 wt % Fe.sub.3 O.sub.4 + 530 50 200018 wt % SiO.sub.2 +5 wt % CoO46 wt % Fe.sub.3 O.sub.4 + 650 10 160026 wt % SiO.sub.2 +28 wt % CoOCo.sub.x Fe.sub.2-x O.sub.3 515 - 62 Prior Art(x = 0.06) 600 Materials(Co,Fe).sub.2 O.sub.3 -- 580 - 60(Co,Fe).sub.3 O.sub.4 700______________________________________
Scanning electron microscope studies have revealed that all of the samples consist of uniformly sized, equiaxed precipitates that are embedded in a glassy matrix. In the case of the rapidly solidified Fe 3 O 4 +SiO 2 , the precipitates are actually cubes. The edges of the precipitates are rounded, indicating that they are probably encased in glass. In many of the samples, strands of glass were present; these strands were sometimes twisted and usually had crystallites on them or within them, growing in an oriented manner along the strand. FIGS. 2 and 3 show strings of cubic γ-Fe 2 O 3 particles in a matrix of SiO 2 -rich glass. Each particle is approximately 0.1 mm on edge.
EXAMPLE 2
Iron oxide containing magnetic oxide powder can be produced from the flakes of Example 1 by chemical removal of the matrix material and collection of the remaining magnetic particles. Flakes may be reacted with a suitable etch solution selected to etch away the glass matrix while leaving intact the magnetic particles. The etch may be heated to an elevated temperature near the glass transition temperature of the glass matrix but well below the melting point of the magnetic oxide particles to accelerate the kinetics of the dissolution reaction.
The undissolved magnetic oxide particles can then be collected, washed to remove traces of etchant solution, and subjected to further processing. Such processing can include sintering or mixing with conventional organic binder materials, well known in the art.
EXAMPLE 3
Iron oxide powder may also be produced from the flakes of Example 1 by mechanically removing the glass matrix. The brittle flakes can be crushed and the magnetic iron oxide precipitate particles separated from the group glass matrix magnetically.
The resulting magnetic iron oxide precipitate particles can be processed further as described in Example 2.
EXAMPLE 4
Shaped magnetic recording media can be fabricated using the flakes prepared according to Example 1. The flakes may be crushed to a suitable size for powder processing i.e. reduced to micron sized particles. These particles can be formed into thick, self-supporting shaped articles, such as disks or drums and sintered. Disks made by this method offer the advantage of addressability from either side.
EXAMPLE 5
Alternatively, magnetic recording media can be made by applying inks containing magnetic iron oxide containing precipitate particles to shaped substrates. Iron oxide containing powders prepared according to the method outlined in Example 2 or 3 can be used to produce inks which can be painted on substrates having the desired shape and sintered to produce a thin solid recording layer.
Thick recording films can be made by combining the iron oxide containing powders of Example 2 or 3 with binders and elastomers to make a "green" i.e. unsintered sheet which can be applied to a substrate of the desired shape and then sintered.
EXAMPLE 6
Thin film magnetic recording media can be sputtered onto substrates selected for their shape and optical properties. Such condensation of materials from the vapor phase results in extremely high cooling rates on the order of 10 12 °/second and can be employed to deposit smooth surfaced 0.1 micron-10.0 micron cobalt ferrite glass matrix films.
Sputtering techniques can also be used to deposit magnetic iron oxide containing precipitates embedded in a glass matrix on metallic substrates having reflective properties suitable for optical recording based on the Faraday and Kerr effects. | A mixture including at least one iron oxide and a mon-magnetic matrix material is melted or vaporized and then heat is rapidly removed from the material. The resulting magnetic oxide precipitates are densely packed in the non-magnetic matrix. The precipitates have a narrow particle size distribution which results in a high signal-to-noise ratio when the oxides are used for magnetic recording purposes. The non-magnetic matrix can be removed to yield homogeneous, small particle iron oxide containing magnetic powder. Alternatively, the non-magnetic matrix/iron oxide material can be processed to yield a shaped recording medium. | 8 |
This application is a continuation-in-part of U.S. Application Ser. No. 079,712, filed Jun. 18, 1993, now abandoned.
FIELD OF THE INVENTION
The instant invention relates to a novel enzymatic process for the stereoselective preparation of chiral epoxide compounds from benzyopyran compounds. The instant invention thus relates to the stereoselective epoxidation or hydroxylation of benzopyran compounds to time chiral epoxide or the corresponding chiral mono or dihydroxy compounds.
SUMMARY OF THE INVENTION
In accordance with the instant invention, a novel process is provided for preparing a chiral epoxide of formula ##STR4## and/or a (+)-trans dihydroxy compound of formula ##STR5##
As used in formula I and II and throughout the specification, the symbols have the following meanings:
a, b, and d are all carbon atoms or one of a, b and d is a nitrogen atom or --NO-- and the others are carbon atoms;
R 1 and R 2 are independently hydrogen, alkyl or arylalkyl; or R 1 and R 2 taken together with the carbon atom to which they are attached form a 5- to 7-membered carbocyclic ring;
R 3 is hydrogen, alkyl, haloalkyl, alkenyl, alkynyl, cycloalkyl, arylalkyl, cycloalkylalkyl,--CN,--NO 2 , --COR, COOR, --CONHR, --CONRR', --CF 3 , S--alkyl, --SOalkyl, --SO 2 alkyl, ##STR6## halogen, amino, substituted amino, OH, --O--alkyl, --OCF 3 , --OCH 2 CF 3 , --OCOalkyl, --OCONRalkyl, --NRCO alkyl, --NRCOOalkyl or --NRCONRR' wherein R and R' in each of the above groups is independently hydrogen, alkyl, haloalkyl, aryl, arylalkyl, cycloalkyl, or (cycloalkyl)alkyl;
R 4 is hydrogen, alkyl,--OH, --O--alkyl, amino, substituted amino,--NHCOR,--CN or --NO 2 ; and
n is an integer of 1 to 3.
The instant process comprises the step of treating a compound of formula ##STR7## with an enzyme or microorganism capable of catalyzing the stereoselective epoxidation of the compounds of formula III to form the chiral epoxide of formula I or the stereoselective hydroxylation to form the chiral dihydroxy compound of formula II.
The invention also includes the process of preparing the trans-(+)-diols of the formula II, comprising the step of treating a racemic trans diol of formula ##STR8## with a lipase or esterase or microorganism capable of producing said lipase or esterase to resolve the racemic diols.
The compounds of formula I are key intermediates in the preparation of compounds having potassium channel activating activity. The chiral dihydroxy compounds of formula II may be converted to the chiral epoxide of formula I, which may then be utilized to prepare compounds having potassium channel activating activity.
The above process may also be used to form the chiral monohydroxy compounds of the formula ##STR9##
DETAILED DESCRIPTION OF THE INVENTION
The following definitions apply to the terms as they are used throughout the specification (unless they are otherwise limited in specific instances) either individually or as part of a larger group.
The term "alkyl" refers to straight and branched chain hydrocarbons, containing 1 to 8 carbons in the normal chain, preferably 1 to 5 carbons such as methyl, ethyl, propyl, butyl, pentyl, the various branched chain isomers thereof such as isopropyl, t-butyl, isobutyl, 4,4-dimethyl-pentyl, 2,2,4-trimethylpentyl, and the like as well as such groups including a halo-substituent, such as F, Br, Cl or I such as CCl 3 or CF 3 , an alkoxy substituent, an aryl substituent, an alkyl-aryl substituent, a haloaryl substituent, a cycloalkyl substituent, an alkyl-cycloalkyl substituent, a hydroxy substituent, an alkylamino substituent, an alkanoylamino substituent, an arylcarbonylamino substituent, a nitro substituent, a cyano substituent, a thiol substituent or an alkylthio substituent.
The terms "alkoxy" and "alkylthio" refer to such alkyl groups as described above linked to an oxygen atom or sulfur atom respectively.
The term "alkenyl" refers to such groups as described above for alkyl, further containing at least one carbon to carbon double bond.
The term "alkynyl" refers to such groups as described above for alkyl, further containing at least one carbon to carbon triple bond.
The term "cycloalkyl" as employed herein includes saturated cyclic hydrocarbon groups containing 3 to 7 ring carbons with cyclopropyl, cyclopentyl and cyclohexyl being preferred.
The term "halogen" or "halo" refers to chlorine, bromine, iodine and fluorine.
The term "aryl" refers to phenyl, 1-naphthyl, 2-naphthyl or mono substituted phenyl, 1-naphthyl, 2-naphthyl wherein said substituents is alkyl of 1 to 4 carbons, alkylthio of 1 to 4 carbons, alkoxy of 1 to 4 carbons, halo, nitro, cyano, hydroxy, amino, --NH--alkyl wherein alkyl is of 1 to 4 carbons, --N(alkyl) 2 wherein alkyl is of 1 to 4 carbons, --CF 3 , ##STR10## (where Y is hydrogen, alkyl of 1 to 4 carbons, alkoxy of 1 to 4 carbons, alkylthio of 1 to 4 carbons, halo, hydroxy or --CF3), --O--CH 2 --cycloalkyl, or --S--CH 2 --cycloalkyl, and di-substituted phenyl, 1-naphthyl, 2-naphthyl wherein said substituents are selected from methyl, methoxy, methylthio, halo, --CF 3 , nitro, amino, and --OCHF 2 . Preferred aryl groups include unsubstituted phenyl and monosubstituted phenyl wherein the substituents are nitro, halo, --CF 3 , alkyl, cyano or methoxy.
The term "heterocyclo" refers to fully saturated or unsaturated rings of 5 or 6 atoms containing one or two O and S atoms and/or one to four N atoms provided that the total number of hetero atoms in the ring is 4 or less. The hetero ring is attached by way of an available carbon atom. Preferred monocyclic hetero groups include 2- and 3-thienyl, 2- and 3-furyl, 2-, 3- and 4-pyridyl, and imidazolyl. The term hetero also includes bicyclic rings wherein the five or six membered ring containing O, S and N atoms as defined above is fused to a benzene ring and the bicyclic ring is attached by way of an available carbon atom. Preferred bicyclic hetero groups include 4, 5, 6, or 7-indolyl, 4, 5, 6 or 7-isoindolyl, 5, 6, 7 or 8-quinolinyl, 5, 6, 7 or 8-isoquinolinyl, 4, 5, 6, or 7-benzothiazolyl, 4, 5, 6 or 7-benzoxazolyl, 4, 5, 6 or 7-benzimidazolyl, 4, 5, 6 or 7-benzoxadiazolyl and 4, 5, 6 or 7-benzofuranzanyl.
The term heterocyclo also includes such monocyclic and bicyclic rings wherein an available carbon atom is substituted with a lower alkyl of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, lower alkoxy of 1 to 4 carbons, halo, nitro, keto, cyano, hydroxy, amino, --NH--alkyl wherein alkyl is of 1 to 4 carbons, --N(alkyl) 2 wherein alkyl is of 1 to 4 carbons, --CF 3 , or --OCHF 2 or such monocyclic and bicyclic rings wherein two or three available carbons have substituents selected from methyl, methoxy, methylthio, halo, --CF 3 , nitro, hydroxy, amino and --OCHF 2 .
The term "substituted amino" refers to a group of the formula --NZ 1 Z 2 wherein Z 1 is hydrogen, alkyl, cycloalkyl, aryl, arylalkyl, (cycloalkyl)alkyl and Z 2 is alkyl, cycloalkyl, aryl, arylalkyl, (cycloalkyl)alkyl or Z 1 and Z 2 taken together with the nitrogen atom to which they are attached are 1-pyrrolidinyl, 1-piperidinyl, 1-azepinyl, 4-morpholinyl, 4-thiamorpholinyl, 1-piperazinyl, 4-alkyl-1-piperazinyl, 4-arylalkyl- 1 -piperazinyl, 4-diarylalkyl- 1-piperazinyl, 1 -pyrrolidinyl, 1-piperidinyl or 1-azepinyl substituted with alkyl, alkoxy, alkylthio, halo, trifluoromethyl or hydroxy.
The term "stereoselective epoxidation" refers to the preferential epoxidation of the 1aS-cis enantiomer of the compound of formula III relative to its 1aR-cis enantiomer. The term "stereoselective hydroxylation" refers to the preferential hydroxylation to form the optically active dihydroxy compounds of formula II.
In accordance with the present invention, it has been found that, in the presence of one or more epoxidizing enzymes or microorganisms producing same, the stereoselective epoxidation of the compounds of the formula III is achieved. The enzymatic epoxidation process of the present invention is advantageous in that it provides high yields of the chiral epoxides of the compounds of formula I with high optical purity. When the reaction is carried out at ambient temperature, for example, an optical purity of greater than about 80% may be obtained with a reaction yield of greater than about 50%. Preferably, an optical purity of greater than 85% with a reaction yield of greater than about 60% may be obtained.
In addition to the chiral epoxide, the present process also comprises the stereoselective hydroxylation of compounds of formula III to produce the chiral trans-dihydroxy compounds of formula II.
Further, the chiral dihydroxy compounds of formula II may be prepared from the racemic trans diols of formula IIa by treatment of the racemic trans diols with lipase, esterase or microorganism capable of supplying said lipase or esterase.
The racemic trans diols of formula IIa are obtained by dissolving racemic epoxide of formula ##STR11## in an organic solvent such as tetrahydrofuran in the presence of water and catalytic amounts of a mineral acid such as perchloric acid.
Compounds of formula Ia can be prepared by methods described in the literature, such as by J. M. Evans et al., J. Med. Chem., (1983), 26, 1582; J. M. Evans et al., J. Med. Chem., (1986), 29, 2194; R.W. Lang et al., Helvetica Chimica Acta, (1988), 71,596; European patent 0205292 A2 and PCT patent 87/07607.
The starting materials of formula III and methods for obtaining them are known (Evans et al., J. Med. Chem., (1983), 26, 1582 and J. Med Chem., (1986), 29, 2194).
The present processes are preferably carded out in an aqueous system such as water or an aqueous buffer.
Any enzyme or microorganism having the ability to catalyze the stereoselective epoxidation or stereoselective hydroxylation of the compounds of formula III as described herein may be employed in the present processes. Two or more as well as single species of microorganism may be employed.
Various enzymes, regardless of origin or purity, are suitable for use in the present invention. The enzyme may, for example, be in the form of animal or plant enzymes or mixtures thereof, cells of microorganisms, crushed cells, extracts of cells, or of synthetic origin.
The enzyme employed, when derived from a microorganism, may be derived either by extracellular expression of the enzyme by the microorganism or by separating intracellularly-prepared enzyme from cellular materials. The enzyme employed may, for example, be an enzyme isolated from a microorganism such as by homogenizing cell suspensions, followed by disintergration, centrifugation, DEAE-cellulose chromatography, ammonium sulfate fractionation, chromatography using gel filtration media such as Sephacryl (cross-linked co-polymer of allyl dextran and N,N 1 -methylene bisacrylamide) chromatography, and ion exchange chromatography such as Mono-Q (anion exchanger which binds negatively charged biomolecules through quaternary amine groups) chromatography. The microbial genera and species discussed below with respect to the use of microorganisms are exemplary of microbial enzyme sources.
Suitable enzymes for the stereoselective epoxidation or stereoselective hydroxylation include those enzymes referred to as epoxidase, alkane epoxidase, monooxygenase, alkane monooxygenase, dioxygenase, p-450 monooxygenase, or epoxide hydratase. Exemplary, commercially available enzymes suitable for use in the present invention include microsomal enzyme preparations, alkene epoxidizing and alkane hydroxylation enzymes, cytochrome p-450 enzymes, monooxygenase, dioxygenase, and hydroxylase enzymes.
The epoxidation and hydroxylation enzyme (cells or cellular materials) may be employed in the free state or immobilized on a support. The enzyme may, for example, be adsorbed onto a suitable cartier, e.g., oxirane-acrylic beads (Eupergit C), diatomaceous earth (porpous Celite Hyflo Supercel), microporous polyproplyene (Enka Accurel® polypropylene powder), or a nonionic polymeric adsorbent such as Amberlite® XAD-2 (polystyrene) or XAD-7 (polyacrylate) from Rohm and Haas Co. Immobilizing the enzyme has the effects of controlling the enzyme particle size, and preventing aggregation of the enzyme particles. Additionally, and preferably, immobilized enzymes may be readily reused in the instant process. Adsorption onto a support such as Celite Hyflo Supercel may be accomplished, for example, by precipitating an aqueous solution of the enzyme with cold acetone in the presence of the support followed by vacuum drying, or in case of a nonionic polymeric adsorbent, incubating enzyme solutions with adsorbent on a shaker for a desired time, removing excess solution and drying the enzyme-adsorbent resins under vacuum. It is particularly preferred to employ enzyme immobilized on an oxirane-acrylic bead support such as Eupergit C in the process of the instant invention.
With respect to the use of microorganisms, the processes of the present invention may be carried out using any microbial cellular material having the ability to catalyze the stereoselective epoxidation or hydroxylation of the compounds of formula III as described herein. In addition, any microorganism capable of supplying lipase or esterase for the resolution of compounds of formula IIa to the chiral diols of formula II may be utilized. The cells may be used in the form of intact wet cells or dried cells such as lyophilized, spray-dried or heat-dried cells. Cells may also be used in the form of treated cell material such as ruptured cells or cell extract.
Suitable microorganisms include genera from bacteria, yeasts and fungi such as Achromobacter, Acinetobacter, Actinomyces, Alkaligenes, Arthrobacter, Aspergillus, Azotobacter, Bacillus, Brevibacterium, Candida, Corynebacterium, Cunninghamella, Curvularia, Diplodia, Flavobacterium, Fusarium, Geotrichum, Hansenula, Helicostylum, Kloeckera, Methylococcus, Methylomonas, Methylosinus, Mortierella, Mucor, Mycobacterium, Nitrosomonas, Nocardia, Penicillium, Pichia, Pseudomonas, Rhizopus, Rhodococcus, Rhodopseudomonas, Rhodotorula, Saccharomyces, Streptomyces, Torulopsis, Trichoderma or Xanthomonas.
The use of microorganisms of the genera Corynebacterium, Rhodococcus and Mycobacterium are preferred for the epoxidation or hydroxylation reactions.
In addition, the following species are preferred for the epoxidation or hydroxylation reactions: Acinetobacter calcoaceticus, Arthrobacter rubellus, Arthrobacter simplex, Brevibacterium fuscum, Candida albicans, Candida lipolytica, Corynebacterium alkanum, Corynebacterium sp., Cunninghamella echinulata, Curvularia lunata, Diplodia gossypina, Geotrichum candidum, Hansenula fabianii, Hansenula polymorpha, Helicostylum elegans, Methylococcus capsulatus, Methylosinus trichosporium, Mortierella alpina, Mortierella ramanniana, Mucor hiemalis, Mycobacterium vacca, Nitorsomonas europea, Nocardia autotrophica, Nocardia corallina, Nocardia globerula, Nocardia meditteranei, Nocardia restricta, Nocardia salmonicolor, Pichia methanolica, Pichia pastoris, Pseudomonas fiuorescans, Pseudomonas oleovorans, Pseudomonas putida, Rhodococcus equi, Rhodococcus erythropolis, Rhodococcus fascians, Rhodococcus rhodochrous, Torulopsis polysporium and Torulopsis glabrata.
Most preferred microorganisms for the epoxidation or hydroxylation reactions include the following strains: Arthrobacter rubellus (ATCC 21495), Corynebacterium alkanum (ATCC 21194), Corynebacterium sp. (ATCC 43752), Cunninghamella echinulata (ATCC 9244), Curvularia lunata (ATCC 12017), Diplodia gossypina (ATCC 10936), Hansenula fabianii (ATCC 58045), Hansenula polymorpha (ATCC 26012), Helicostylum elegans (ATCC 12745), Mortierella ramanniana (ATCC 38191 and ATCC 24786), Mucor hiemalis (ATCC 89778), Mycobacterium vacca (ATCC 29678), Nocardia corallina (ATCC 31338), Nocardia globerula (ATCC 21505), Pseudomonas putida (ATCC 11172 and ATCC 23287), Pseudomonas oleovorans (ATCC 9347) and Rhodococcus erythropolis (ATCC 4277).
While any microorganism, including those listed above for the epoxidation or hydroxylation reactions, which are capable of providing a lipase or esterase which resolves the racemic trans diol may be utilized, the microorganisms Candida, Pseudomonas or Geotrichurn are preferred for the resolution reactions.
The use of genetically engineered organisms is also contemplated. The host cell may be any cell, e.g. Escherichia coli, modified to contain a plasmid bearing enzymes that catalyzes the epoxidation or hydroxylation reactions or that resolves the substrates.
The term "ATCC" as used herein refers to the accession number of the American Type Culture Collection, 12301 Parklawn Drive, Rockville, Md. 20852, the depository for the organism referred to.
When microorganisms are employed for the processes of this invention, the reactions may, for example, be carried out as a single-step process comprising simultaneous fermentation and transformation of the compounds of formula III or IIIa, or resolution of compounds of formula IIa or as a two-step fermentation and subsequent transformation process.
In a single-step process, the microorganisms used may be grown in an appropriate medium containing carbon and nitrogen sources. The starting formula III, IIIa, or IIa compounds may be added to the microbial cultures, and transformation of the formula III, IIIa, or Ha compounds to the formulae I or II compounds continued until a desired conversion is obtained.
In a two-step process, microorganisms may, in the first step, be grown in an appropriate medium by fermentation exhibiting the desired epoxidizing enzyme activity. The cells may then be harvested and suspended, for example, in an appropriate buffered solution to prepare cell suspensions. The formula III compounds may be mixed with the microbial cell suspensions, and the transformation of formula III compounds to the desired product catalyzed by the cell suspensions. The reaction may be continued until a desired conversion of the formula III compounds is obtained.
Culture media may be employed which provide nutrients necessary for the growth of the microbial cells. A typical medium for growth includes necessary carbon sources, nitrogen sources, and trace elements.
Carbon sources include sugars such as maltose, lactose, glucose, fructose, glycerol, sorbitol, sucrose, starch, mannitol, and the like; organic acids such as sodium acetate, sodium citrate, and the like; amino acids such as sodium glutamate, and the like; alcohols such as ethanol, propanol, and the like. The carbon source may be added during transformation. Also, formula III compounds may be added as an inducer during growth of the microorganisms.
Nitrogen sources include N-Z Amine A, corn steep liquor, soy bean meal, beef extracts, molasses, baker's yeast, tryptone, nutrisoy, sodium nitrate, ammonium sulfate, and the like.
Trace elements include phosphates, magnesium, manganese, calcium, cobalt, nickel, iron, sodium, and potassium salts.
Typical preferred media are as follows:
______________________________________Medium 1Beef extract 5 gPeptone 7.5 gNaCl 2.5 gGlucose 5 gYeast extract 1.5 gMalt extract 1.5 gUcon antifoam* 0.1 gWater 1 LiterMedium 2Cerelose 22 gYeast Extract 10 gMalt Extract 10 gPeptone 1 gWater 1 Liter pH = 6.8______________________________________ *Polysiloxanes
Microorganisms may be grown in Medium 1, for example, for 24 to 48 hours at 280 rpm agitation and 28° C. to 30° C., for inoculum development. A fermentor containing Medium 2 (10%) may then be inoculated with microorganisms grown in Medium 1. An exemplary arrangement for fermentation of approximately 190 L of Medium 2 may, for example, include a 250 L fermentor which is equipped with three Rushton (flat-blade turbine) impellers, a sparger, a pH controller, a dissolved oxygen (DO) meter, a temperature controller, a foam sensor with automatic antifoam addition, and inlet and exhaust air filters.
The efficiency of the process may be affected by both the initial amount of formula III or IIa substrate used and by the timing and amount of substrate added during the process. Substrate may be added batchwise, for example, every one to 12 hours, or continuously during the transformation process by growing cells in a one-step fermentation, or by cell-suspensions of microorganisms as in a two-step fermentation/ transformation process.
While it is desirable to use the least amount of enzyme possible, the amount of enzyme required will vary depending upon the specific activity of the enzyme employed. The enzyme is, in general, preferably added to the reaction solution in an amount of from about 0.01 to about 10 mg of enzyme per mg of formula III or IIa compound, most preferably, from about 0.1 to about 2 mg enzyme per mg of formula III or IIa compound.
Preferred initial concentrations of formula III or IIa substrate are those between about 10 mg/mL and about 100 mg/mL, particularly between about 5 mg/mL and 50 mg/mL, based on cell concentration. Additional substrate is preferably added in amounts such as those between about 5 mg/mL and about 10 mg/mL.
The pH of the medium may be maintained between about 4.0 and about 9.0, preferably between about 5.5 and about 7.0, during growth of microorganisms and during the transformation process.
Buffers such as tris-HCl phosphates, sodium acetate and the like may be used to prepare suspensions of microbial cells to conduct the transformation process.
The temperature of the reaction mixture is a measure of the heat energy available for the transformation process. The reaction temperature may be selected and maintained to ensure that there is sufficient energy available for the process. A temperature range from about 15° C. to 60° C., especially from about 20° C. to 35° C., is preferred for the transformation.
The agitation and aeration of the reaction mixture affects the amount of oxygen available during the transformation process which may be conducted, for example, in shake-flask cultures or fermenter tanks during growth of microorganisms in a single-step or two-step process. An agitation range of from about 50 to about 1000 rpm is preferable, with a range of from about 50 to about 500 rpm being preferred. Aeration rates of from about 1 to about 5 volumes of air per volume of media per minute (i.e., 1 to 5 v/vt) are preferred.
The reaction time may be appropriately varied depending upon the amount of enzyme used and its specific activity. Reaction times may be reduced by increasing the reaction temperature and/or increasing the amount of enzyme added to the reaction solution.
The optimum reaction time for the transformation process generally ranges from about 12 to about 168 hours, preferably 24 to 120 hours, measured from the time of initially treating the substrate (formula III or IIa compound) with a microorganism to the time at which a desired conversion of formula III or IIa compound to formula I or II is achieved. The compounds of formulae I and II may be purified by known methodologies such as extraction, distillation, crystallization, column chromatography, and the like.
The compounds of formula I and formula II (via conversion to formula I) may be utilized to prepare compounds having potassium channel activation activity.
The chiral dihydroxy compounds of formula II may be converted to the epoxides of formula I by reaction with a R-sulfonyl halide (where R is an alkyl such as methyl or CF 3 , or an aryl) such as methanesulfonyl chloride or p-toluenesulfonyl chloride to form compounds of formula ##STR12##
Subsequent treatment with an organic base such as a tertiary amine (for example: 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo-[4.3.0]-non-5-ene, triethylamine) in an organic solvent such as dimethylformamide or tetrahydrofuran or subsequent treatment with an inorganic base such as potassium carbonate in a solvent such as dimethylformamide, acetone, methylethyl ketyone or tetrahydrofuran produces the chiral epoxide of formula I.
Exemplary potassium channel activators include pyranyl cyanoguanidine derivatives of the formula ##STR13## where a, b, d, R 1 , R 2 , R 3 and R 4 are as defined for formula I and ##STR14## R 6 is hydrogen, hydroxy or ##STR15## R 7 and R 8 are independently hydrogen, alkyl, alkenyl, aryl, (heterocyclo)alkyl, heterocyclo, arylalkyl, cycloalkyl, (cycloalkyl)alkyl or substituted alkyl wherein the substituents include alkoxy, alkylthio and substituted amino; or R 7 and R 8 taken together with the nitrogen atom to which they are attached form 1-pyrrolidinyl, 1-piperidinyl, 1-azepinyl, 4-morpholinyl, 4-thiamorphilinyl, 1-piperazinyl, 4-alkyl-1-piperazinyl or 4-arylalkyl-1-piperazinyl, wherein each of the so-formed groups can be substituted with alkyl, alkoxy, alkylthio, halogen or trifluoromethyl; and
R 9 and R 10 are independently hydrogen, alkyl, alkenyl, aryl, arylalkyl, cycloalkyl or (cycloalkyl)alkyl; or R 10 can be an aryl group fused to 2 carbon atoms of the cyanoguanidine ring portion.
Compounds of formula VI and methods of preparing such compounds are disclosed in U.S. Pat. No. 5,140,031, the disclosure of which is incorporated by reference herein.
Preferred compounds of formula VI are those ##STR16## where R 5 is and R 7 is mono- or di- substituted phenyl.
An exemplary method of preparing the compounds of formula VI where R 5 is ##STR17## using the intermediates of formula I prepared as disclosed herein includes treatment of compounds of formula I with an amine such as ammonia to provide the amines of formula ##STR18##
The amine of formula VII is then treated with an isocyanide dihalide of the formula
R.sup.8 --N═C(X).sub.2 (VIII)
(where R 8 is other than hydrogen and X is a halogen, preferably chlorine) in solvent such as dichloromethane, 1,2 dichloroethane, acetonitrile, ethyl acetate or preferably an alcoholic solvent such as isopropyl alcohol or ethanol, containing a tertiary amine such as diisopropylethylamine to form a compound of formula ##STR19##
Alternatively treatment of compounds of formula VII with an isothiocyanate of the formula
R.sup.8 --N═C═S (X)
such as 4-chlorophenylisothiocyanate provides a thiourea of formula ##STR20## Subsequent treatment of the thiourea of formula XI with a carbodiimide such as 1-ethyl-3-(3-dimethylaminopropyl)cabodiimide hydrochloride (WSC) provides the compounds of formula IX.
Treatment of compounds of formula IX with cyanamide in a solvent such as alcohol or acetonitrile, optionally in the presence of a base such as triethylamine or 2,6-lutidine provides the compounds of formula VI where R 6 is hydroxy. Compounds of formula VI where R 6 is --OC(O)CH 3 may be prepared by acetylation of the compounds of formula VI where R 6 is hydroxy. Compounds of formula VI where R 6 is hydrogen may be prepared by dehydration of the compounds of formula VI where R 6 is hydroxy, followed by reduction by procedures known in the art.
Preferred compounds of formula VIII include substituted alkyl and aryl isocyanide dihalides such as substituted phenyl isocyanide dichlorides. The most preferred compounds of formula VIII is 4-chlorophenyl isocyanide dichloride. Substituted alkyl and aryl isocyanide dihalides are known (E. Kuhle, "Carbonic Acid Derivatives from Formamides", Angew, Chem. Int, Ed., (1962), 1,647-652; D. Ferchland et al., "Process for the Preparation of Aryl Isocyanide-Dichlorides", U.S. Pat. No. 4,401,603; and E. Kuihle et al., "New Methods of Preparative Organic Chemistry-Reactions of Isocyanide Dihalides and their Derivatives", Angew, Chem. Int. Ed., (1969), 8, 20-34).
The following examples and preparations describe the manner and process of making and using the preferred embodiments of the invention and are illustrative rather than limiting. It should be understood that there may be other embodiments which fall within the spirit and scope of the invention as defined by the claims appended hereto.
EXAMPLE 1
The substrate for this example was the compound having the formula ##STR21## and the name 2,2-dimethyl-2H-1-benzopyran-6-carbonitrile. The desired product was the compound having the formula ##STR22## and the name (lαS-cis) -1α,7β-Dihyro-2,2-dimethyl-2H-oxireno[c][-1]benzopyran-6- carbonitrile.
The microorganism Corynebacterium sp. (ATCC 43752) was maintained in a vial in liquid nitrogen. For the development of inoculum, one vial was inoculated into 100 mL of medium 1 in a 500-mL flask and incubated at 28° C. and 280 rpm on a shaker for 48 hours. After growth of the microorgansim, 10 mL of culture was inoculated into a 500-mL flask containing 100 mL of medium 2 and incubated at 28° C. and 250 rpm on a shaker.
Cells were harvested and suspended in 10 mM potassium phosphate buffer pH 6.0. 10mL of 20% w/v cell-suspensions were prepared. Cell-suspensions were supplemented with 10 mg of substrate (compound XII) and 50 mg of glucose and the transformations were conducted at 28° C., 150 rpm for 48 hours. One volume of sample was taken and extracted with four volumes of toluene: tet. butyl methyl ether, 1:1 mixture and the separated organic phase was filtered through a 0.2 mm LID/x filter and collected.
Samples (toluene: tet. butylmethylether, 1:1 mixture) were analyzed for substrate and product concentration by gas chromatography.
An HP ultra-2 column (25 meter length) was used. The injection temperature was 250° C., the detection temperature was 250° C., and the oven temperature was 205° C. The retention times for substrate (compound XII) was 2.6 minutes and the product (compound XIII) was 3.4 minutes.
The separation of the two enantiomers of the racemic epoxide was achieved on a chiralpak AD column. The mobile phase consisted of hexane:ethanol 95:5 mixture. The flow rate was 1 mL/minute and the detection wavelength was 254 nm. The refractive index detector (HP 1047A) was also used. The retention times for the desired enantiomer (compound XIII) was 15 minutes and the undesired enantiomer was 13 minutes. The reaction yield of compound XIII was 65% having an optical purity of 90%.
Experimental results obtained using other microorganisms grown on medium 2 and following the procedure of Example 1 are shown in Table 1 below.
TABLE 1______________________________________ Reaction Optical Yield Purity Compound CompoundMicroorganism XIII (%) XIII (%)______________________________________Pseudomonas putida ATCC 23287 35 85Pseudomonas oleovorans ATCC 29347 30 82Corynebacterium alkanum ATCC 21194 45 80Curvularia lunata ATCC 12017 20 78Helicostylum elegans ATCC 12745 30 85Diplodia gossypina ATCC 10936 35 75Nocardia corallina ATCC 31338 60 80Arthrobacter rubellus ATCC 21495 25 82Cunninghamella echinulata ATCC 9244 20 90Mucor hiemalis ATCC 89778 25 88Rhodococcus erythropolis ATCC 4277 60 88Hansenula polymorpha ATCC 26012 50 88Mortierella ramanniana ATCC 24786 60 75______________________________________
EXAMPLE 2
The substrate for this example was the compound of the formula XII having the name 2,2-dimethyl 2H-1-benzopyran-6-carbonitrile (as in Example I). The desired products were (compounds of formulae XIV, XV and XVI as below): ##STR23## having the names: Compound XIV: 4-Hydroxy-2,2-dimethyl-6-carbonitrile-2H-1-benzopyran-3-ol;
Compound XV: 3-Hydroxy-2,2-dimethyl-6-carbonitrile-2H-1-benzopyran-4-ol; and
Compound XVI: (+)-trans-3,4-Dihydroxy-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-6-carbonitrile.
Microorganisms listed in Table 2 below were grown as described in Example 1. The reactions were carried out as described in the Example 1 using compound XII as the substrate. Products (compound XIV, XV and XVI) were analyzed by GC assays and the optical purity was determined by Chiral HPLC assays. Experimental results obtained are shown in Table 2 below.
TABLE 2______________________________________ Optical Reaction Reaction Reaction Purity Yield Yield Yield Com- Compound Compound Compound poundMicroorganism XIV (%) XV (%) XVI (%) XVI (%)______________________________________Corynebac- 2 3 80 92terium sp.ATCC 43752Pseudomonas 1.5 4 70 91putidaATCC 23287Pseudomonas 0.5 5 65 90oleovoransATCC 29347Corynebac- 0.2 2 45 88terium alkanumATCC 21194Curvularia 0.4 6 20 85lunataATCC 12017Helicostylum 0.6 5 15 80elegansATCC 12745Diplodia 1.0 4 40 90gossypinaATCC 10936Nocardia -- 3 65 75corallinaATCC 31338Arthrobacter -- 2 40 91rubellusATCC 21495Cunninghamella -- 6 55 92echinulataATCC 9244Mucor hiemalis -- 4 60 88ATCC 89778Rhodococcus 0.4 2 70 92erythropolisATCC 4277Hansenula 0.8 5 50 90polymorphaATCC 26012Mortierella 1.0 3 81 76ramannianaATCC 24786______________________________________
EXAMPLE 3
The substrate for this example was the compound of the formula XII having the name 2,2-dimethyl-2H-1-benzopyran-6-carbonitrile (as in Example 1 ). The desired product was the compound of the formula XIII and the name (1αS-cis) -1α,7β-dihydro-2,2benzopyran-6-carbonitrile (as in Example 1).
The microorganisms listed in Table 3 were maintained in a vial in liquid nitrogen. For development of inoculum, one vial was inoculated into 100 mL of medium 1 in a 500-mL flask and incubated at 28° C. and 280 rpm on a shaker for 48 hours. After growth of the microorganism, 10 mL of culture was inoculated into a 500-mL flask containing 100 mL of medium 2 containing 0.2% substrate (compound XII) and incubated at 28° C. and 250 rpm on a shaker.
After 24 hours of growth, medium 2 (50 mL) was supplemented with 50 mL of culture (grown for 24 hours) and 1 mg/mL of compound XII was added to the medium. The epoxidation reaction was further continued at 280° C., 250 rpm on a shaker for 96 hours. The concentration of product XIII and optical purity of product XIII were determined as described in the Example 1. Experimental results obtained are shown in Table 3 below.
TABLE 3______________________________________ Reaction Optical Yield Purity Compound CompountMicroorganism XIII (%) XIII (%)______________________________________Corynebacterium sp. ATCC 43752 50 91Pseudomonas putida ATCC 23287 30 85Pseudomonas oleovorans ATCC 29347 28 82Corynebacterium alkanum ATCC 21194 40 81Curvularia lunata ATCC 12017 15 77Helicostylum elegans ATCC 12745 25 82Diplodia gossypina ATCC 10936 30 75Nocardia corallina ATCC 31338 45 80Arthrobacter rubellus ATCC 21495 15 81Cunninghamella echinulata ATCC 9244 10 91Mucor hiemalis ATCC 89778 20 86Rhodococcus erythropolis ATCC 4277 40 85Hansenula polymorpha ATCC 26012 45 88Mortierella ramanniana ATCC 24786 42 78______________________________________
EXAMPLE 4
The substrate for this example was the compound of formula XII having the name 2,2-dimethyl 2H-1-benzopyran-6-carbonitrile (as in Example 1 ). The desired products were the compounds of formula XIV, XV and XVI as in Example 2.
The microorganisms listed in Table 4 were grown as described in Example 3 and the reactions were carded out as described in Example 3. The product concentration of compounds XIV, XV and XVI were determined by GC assays. The optical purity of compound XVI was determined by chiral HPLC. Experimental results obtained using various microorgansims are shown in Table 4.
TABLE 4______________________________________ Reaction Reaction Reaction Optical Yield Yield Yield Purity Com- Com- Com- Com- pound pound pound poundMicroorganism XIV (%) XV (%) XVI (%) XVI (%)______________________________________Corynebacterium sp. 0.4 2 65 91ATCC 43752Pseudomonas putida 0.3 3 60 90ATCC 23287Pseudomonas oleovo- 0.2 5 55 89rans ATCC 29347Corynebacterium 0.4 2 40 84alkanum ATCC 21194Curvularia lunata 0.1 6 15 81ATCC 12017Helicostylum elegans 0.15 4 12 91ATCC 12745Diplodia gossypina 0.8 3 35 74ATCC 10936Nocardia corallina -- 2 60 90ATCC 31338Arthrobacter rubellus -- 1 38 92ATCC 21495Cunninghamella -- 5 50 87echinulata ATCC 9244Mucor hiemalis -- 4 55 91ATCC 89778Rhodococcus 0.4 2 65 90erythropolis ATCC4277Hansenula polymor- 0.6 5 45 91pha ATCC 21012Mortierella ramanni- 0.1 2 83 79ana ATCC 24786______________________________________
EXAMPLE 5
Use of Whole Cells: Variation in Reaction Time (Two-Stage Process)
The substrate for this example was the compound of formula XII and the desired product was the compound of formula XIII as described in Example 1.
Cells of Corynebacteriurn sp. ATCC 43752 were grown in 100 mL of Medium 1 contained in 500-mL flasks. Growth was carried out at 28° C. for 48 hours at 280 rpm. 100 mL of cultures were innoculated into 15 L of Medium 2 contained in a fermentor. Medium 2 was supplemented with 0.2% of compound XII. Growth in the fermentor was carried out at 28° C., 5 liters per minute (LPM) aeration and 500 rpm agitation for 48 hours. Cells were hatwested from the fermentor and used for epoxidation ("biotransformation") of compound XII to compound XIII.
Cells (200 grams) were suspended in 1 liter of 100 mM potassium phosphate buffer, pH 6.0 and homogeneous cell suspensions were prepared. 1 gram of compound XII and 10 grams of glucose were added to the cell suspensions and the biotransformation of compound XII to compound XIII was carried out at 28° C., 160 rpm for 96 hours. After 48 hours, an additional 35 grams of glucose were added and the biotransformation was continued for 96 hours at 28° C., 160 rpm. Samples were prepared and product yield and optical purity were determined as described in Example 1. The results obtained are summarized in Table 5 following.
TABLE 5______________________________________ Reaction Yield Optical PurityReaction Time Compound Compound(Hours) XIII (%) XIII (%)______________________________________24 10 --48 20 --72 34 --96 48 90______________________________________
EXAMPLE 6
Use of Whole Cells; Variation in Reaction Time (Single-Stage process)
The substrate for this example was the compound of formula XII and the desired product was the compound of formula XIII as described in Example 1.
Cells of Corynabacterium sp. ATCC 43752 were grown in 100 mL of Medium 1 contained in 500-mL flasks. Growth was carded out at 28° C. for 48 hours at 280 rpm. 100 mL of cultures were inoculated into 10 L of Medium 2 contained in a fermentor. Medium 2 was supplemented with 0.2% of compound XII. Growth in the fermentor was carried out at 28° C., 15 liters per minute (LPM) aeration and 500 rpm agitation for 24 hours.
After 24 hours growth in a fermentor, 5L of medium 2 containing 15 grams of compound XII was added to the fermentor and the fermentation/biotransformation was continued at 28° C., 15LPM aeration and 500 rpm agitation for 96 hours. Samples were prepared and product yield and optical purity were determined as described in Example 1. The results obtained are summarized in Table 6 following:
TABLE 6______________________________________ Reaction Yield Optical PurityReaction Time Compound Compound(Hours) XIII (%) XIII (%)______________________________________48 20 --72 30 --96 45 90120 60 92______________________________________
EXAMPLE 7
Use of Whole Cells: Variation in Reaction Time (Single-stage process)
The substrate for this example was the compound of formula XII and the desired product was the compound of formula XVI as described in Example 2.
Cells of Corynebacterium sp. ATCC 43752 were grown in 100 mL of Medium 1 contained in 500-ml flasks. Growth was carried out at 28° C. for 48 hours at 280 rpm. 100 mL of cultures were inoculated into 10 L of Medium 2 contained in a fermentor. Medium 2 was supplemented with 0.2% of compound XII. Growth in the fermentor was carded out at 28° C., 15 liters per minutes (LPM) aeration and 500 rpm agitation for 24 hours.
After 24 hours of growth in a fermentor 5L of Medium 2 containing 15 grams of compound XII was added to the fermentor and the fermentation/biotransformation was continued at 28° C., 15 LPM aeration and 500 rpm agitation for 96 hours. Samples were prepared and product yield and optical purity were determined as described in Example 2. The results obtained are summarized in Table 7 following.
TABLE 7______________________________________ Reaction Yield Optical PurityReaction Time Compound Compound(Hours) XVI (%) XVI (%)______________________________________24 15 --48 25 --72 40 --96 65 --120 80 90______________________________________
EXAMPLE 8
Use Of Cell Extracts and Co-factor
The substrate for this example was the compound of formula XII and the desired product was the compound of formula XIII as described in Example 1.
Cells of Corynebacterium sp. ATCC 43572 were grown in Medium 1 and Medium 2 as described in Example 1:
Cells (300 grams) were suspended in 1.5 L of 0.1M potassium phosphate buffer, pH 6.0. The homogenized cell suspensions were disintegrated at 4° C. by a Microfluidizer at 13,000 psi pressure. The disintegrated cell suspension was centrifuged at 10,000 rpm for 30 minutes. The clear supernatant ("cell extract") was used for the biotransformation of compound XII to compound XIII.
One liter of cell extract was supplemented with 0.7 grams of substrate (compound XII), glucose dehydrogenase (500 units), 0.7 mM NAD + (nicotinamide adenine dinucleotide), and 25 grams of glucose. The reaction was carried out in a pH stat at pH 6.0, 150 rpm agitation, and 28° C. Periodically, samples were taken and analyzed for the reaction yield and optical purity of compound XIII as described in Example 1. The results obtained are those shown in Table 8 following:
TABLE 8______________________________________ Reaction Reaction OpticalReaction Yield Yield PurityTime Compound Compound Compound(Hours) XIII g/L XIII (%) XIII (%)______________________________________96 0.3 45 92______________________________________
In the above procedure, the NADH cofactor used for the biotransformation of compound XII to compound XIII was, concurrent with the biotransformation, formed and regenerated using glucose dehydrogenase, AND + , and glucose as shown below: ##STR24##
EXAMPLE 9
Use of Cell Extracts and Co-factor
The substrate for this example was the compound of formula XII and the desired product was the compound of formula XVI as described in Example 2.
Cells of CoGnebacterium sp. ATCC 43572 were grown on Medium 1 and Medium 2 as described in Example 3.
Cells (300 grams) were suspended in 1.5 L of 0.1 M potassium phosphate buffer, pH 6.0. The homogenized cell suspensions were disintegrated at 4° C. by a Microfluidizer at 13,000 psi pressure. The disintegrated cell suspension was centrifuged at 10,000 rpm for 30 minutes. The supernatant ("cell extract") was used for the biotransformation of compound XII to compound XVI.
One liter of cell extract was supplemented with 0.7 grams of substrate (compound XII), glucose dehydrogenase (500 units), 0.7 mM NAD + (nicotinamide adenine dinucleotide), and 25 grams of glucose. The reaction was carded out in a pH stat at pH 6.0, 150 rpm agitation, and 28° C. Periodically, samples were taken and analyzed for the reaction yield and optical purity of compound XVI as described in Example 3. The results obtained are those shown in Table 9 following:
TABLE 9______________________________________ Reaction Reaction OpticalReaction Yield Yield PurityTime Compound Compound Compound(Hours) XVI (g/L) XVI (%) XVI (%)______________________________________120 0.6 85 91______________________________________
In the above procedure, the NADH cofactor used for the biotransformation of compound XII to compound XVI was, concurrent with the biotransformation, formed and regenerated using glucose dehydrogenase, NAD + , and glucose as shown below: ##STR25##
EXAMPLE 10
(+)-trans 3,4-Dihydro-3-4-dihydroxy-2,2-dimethyl-2H-1-benzopyran-6-carbonitrile
6--Carbonitrile-2,2-dimethyl-(3,4)-epoxy-1,2,3,4-tetrahydronapthalene (0.027 mol, 5.0 gin) was dissolved in tetrahydrofuran (12 mL). To this solution was added water (0.5 mL) and one drop of perchloric acid (70%). The reaction mixture was stirred at room temperature for 30 minutes. The progress of the reaction was followed by GC. After all epoxide was converted, water (25 mL) was added and the resulting mixture extracted twice with dichloromethane (25 mL). The organic layer was then washed with 0.7M sodium bicarbonate solution. The organic extract was then dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure to produce 4.8 gm of (+)-trans 3,4-dihydro-3-4-dihydroxyo2,2-dimethyl-2H-1-benzopyran-6-carbonitrile as a white powder (81 M% yield), and 98% chemical purity as analyzed by GC.
1H NMR (CDCl 3 , 300 MHz): δ1.22 (s, 3H, CH 3 ), 1.45 (s, 3H, CH 3 ), 3.18 (s, 2H, OH), 3.62 (d, J=8.5 Hz, 1H, H-3), 4.68 (d, J=8.5 Hz, 1H, H-4), 6.82 (d, J=10 Hz, 1H, H-8), 7.31 (s, 1H, H-5), 7.4 (d, J=1.1 Hz, 1H, H-7); 13 C NMR (CDCl 3 ,75.46 MHz): δ156.16, 133.14, 132.55, 124.7, 119.35, 117.97, 103,56, 75.6, 68.48, 49.45, 26.97, 26.61. Analysis calc'd for C 12 H 13 NO 3 : C, 65.71; H, 5.93; N, 6.38; Found: C, 65.82; H, 6.01; N, 6.45.
EXAMPLE 11
Stereoselective esterification of the racemic diol ((±)trans-3,4-dihydroxy-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-6-carbonitrile) was carried out with an excess of isopropenyl acetate (0.16M) as the acyl donor, and 4.5 mM diol in toluene (10 mL), in the presence of water (1 mL/L) in 50 mL flasks. The reaction was started by addition of lipase (8 mg/mL). The reaction temperature was 30° C., and agitated at 400 rpm. The progress of the reaction was monitered by chiral HPLC.
Stereoselective esterification of was conducted in toluene, with an excess of isopropenyl acetate (0.32M) as the acylating agent. The title compound was dissolved in toluene (10 g/L, 0.046M), to which isopropenyl acetate was added. To start the reaction, 8 g/L Candida cylindraceae lipase from Biocatalyst was added. The reaction temperature was 30° C. and agitated at 450 rpm. During the reaction the optical purity of the diol was monitored by chiral HPLC. 5 The reaction mixture containing the enzyme was filtered using a Whatman 54 filter paper to remove the lipase. The toluene layer (1 L) was extracted with water (2×2L) to remove the title compound from toluene. The water layer was separated, to which SP-207 resin (2% w/v) was added and stirred overnight. The resin was then removed by filtration through a O coarse sintered glass funnel, then washed with water (2×100 mL) and air dried. The dried resin was then washed twice with cyclohexane (100 mL). The washed resin was then extracted with tert-butyl methyl ether (2×100 mL). The organic layer was dried over anhydrous magnesium sulfate, then the solvent removed under reduced pressure to produce a yellow waxy solid. The title compound was further purified by preparative chromatography on reverse phase C-18 column and water:methanol (1: 1) as the mobile phase. The results are shown in Table 10 below. Reactions with lipase PS-30 and Geotrichurn candidurn lipase were carried out under similar conditions and the results are also shown in Table 10.
TABLE 10______________________________________ Diol OpticalEnzyme Diol Yield (%) Purity (%)______________________________________Candida cylindraceae 45 97lipasePseudomonas sp. 40 90(Amano PS-30)Geotrichum candidum 40 87lipase______________________________________ | An enzymatic process for the preparation of chiral epoxides, monohydroxy or dihydroxy compounds of formula ##STR1## by the stereoselective epoxidation or hydroxylation of benzopyrans of formula ##STR2## or resolution of compounds of formula ##STR3## The compounds of formula I and II are intermediates useful in the preparation of pyranyl cyanoguanidine derivatives. | 2 |
This is a Continuation of International application PCT/DE97/01896, with an international filing date of Aug. 29, 1997, the disclosure of which is incorporated into this application by reference. International Application PCT/DE97/01896, in turn, claims priority from German Application No. 19635679.2, filed Sep. 3, 1996, the disclosure of which is also incorporated in this application by reference.
FIELD OF AND BACKGROUND OF THE INVENTION
The invention relates to new and useful improvements to a man-machine interface (MMI) for airport traffic control purposes. More particularly, the invention relates to a man-machine interface (MMI) for safe taxiing and/or approach-departure control at an airport, having a display area on which processes and situations at the airport can be displayed and, possibly, can be influenced, for example the movements and the current positions of aircraft, and, possibly, vehicles, and lighting system switching states, etc.
The man-machine interfaces (MMI) in airport control centers, for example in air traffic control towers, have until now comprised relatively small screens, arranged in groups alongside one another. The screens are connected to computer units in which the information relating to an airport is collected, processed and changed to a form which can be displayed. Examples, in particular relating to processing, can be found in U.S. Pat. Nos. 5,374,932, 5,485,151 and 5,262,784, which are incorporated into the present application by reference. Also incorporated by reference are: EP 0725283, FR 2634945, EP 0714082, DE 19504923, FR 2668012, DE 4216281, GB 2289556, and DE 4304562.
OBJECTS OF THE INVENTION
It is therefore a first object of the invention to change the large number of displays, masks etc. which can be displayed and processed on the small individual screens that are already known, into a form which can be displayed better and is more comprehensible. This will relieve the load on the controllers and improve not only taxiing safety, but also the safety of approach and departure movements and the processes linked to them. In particular it will make them even safer and simplify the controllers' work, thus allowing their concentration span to be lengthened.
SUMMARY OF THE INVENTION
These and other objects are achieved by a MMI designed as a screen whose diagonal is more than 19 inches, in particular more than 21 inches. Screens larger than 19 inches have not so far been used in towers at airports, and although the use of screens of up to 21 inches has already been discussed, they have not yet been introduced. The previous screen sizes were generally regarded as being satisfactory. Furthermore, disadvantages included constriction of the controllers' field of view. Surprisingly, however, the screen size according to the invention offers more advantages than disadvantages.
A refinement of the invention provides for the MMI to be designed to be interactive. In previously known MMIs for airports, the display unit and the switching devices, which are preferably designed as keyboards, have been separated. This means that the controllers have to concentrate even harder, and have to continuously check that the right switches have been operated. An interactive configuration overcomes these problems and improves safety.
Another object of the invention is to provide a flat screen for the MMI, in addition to the screen being larger than ever before. Surprisingly, this makes it possible for even larger-format screens, for example with screen diagonals of more than 100 cm, to be arranged in the field of view of controllers in airport towers, while maintaining sufficient visibility of the runways, taxiways etc. This has not been possible with previously used monitors, since they are very deep. A particularly advantageous feature of the invention is to use a high-resolution flat screen with a daylight (sunlight) capability. Flat screens which can be used in daylight are already known, for example from the document “Tageslichttaugliche Flachdisplays” [Flat displays suitable for daylight use] from Siemens AG, Bereich Datentechnik, [Data Technology Division] dated October 1995 and incorporated herein by reference. However, the size of these known flat screens is only 10.4 inches. It is therefore impossible to use them to display the large amount of information required on screens in air traffic control towers. These flat screens have booster light sources to make them suitable for use in daylight. Equivalent techniques can also be used for large flat screens and their superimposed displays.
To simplify the controller's work, the invention advantageously provides for the use of touch screens for integrated displays and for controlling facilities, for example stop bars etc., at an airport, thus allowing direct traffic management at the airport. This will allow the controllers to issue commands and control instructions in the tower, safely and without the controller having to change the direction he is looking in, in a far better way than when attempting to carry out “blind” operation with a keyboard and a mouse.
It has been found to be advantageous in this case to display menus and windows on the MMI screen. These menus and windows can be called up, added to and edited using a keyboard, as well as using Windows technology, for example with a mouse. Traffic-relevant data can thus be corrected and adapted on the same screen as the switching functions, resulting in an integrated process for the controller. As one example, all the activities relating to the traffic at an airport can be processed in one place such that, and this is particularly advantageous, it is possible for one man to control operations when traffic levels are low, even at a large airport.
The screen can advantageously display both aircraft and vehicle movement areas at the airport, preferably as processed video. Even at a large airport, the main traffic areas can be displayed with sufficiently high resolution on a screen size of at least 100 cm. The two or more runways and taxiways can be displayed either as processed video or as raw video, with the positions of stop bars and other signal transmitters, sensors and their switching and display states also being indicated and/or superimposed on the processed video. At the same time, the display can also show the flight numbers of the aircraft, possibly as well as their type labels. Even with this large amount of detail, a screen size of 19 or 21 inches can provide the required clarity, according to the invention, particularly if very large formats are used.
The invention envisages lists of aircraft on the approach, preferably listed alphanumerically, with aircraft that have recently departed also being listed, likewise alphanumerically, and preferably on free areas of the display, for example in the corners or at the sides of the video. This will provide the controller with a complete overview of airborne and taxiing traffic in his area of responsibility. Departure control is particularly important for gate allocation, and the docking process can advantageously be displayed as well, for example superimposed on the corresponding airport building display, for gate allocation.
The various video displays will preferably have aircraft position indications added, with aircraft indications and, possibly, with associated selected flight plan data, possibly together with vehicle identifications. A transponder system is particularly advantageous in this case, to provide identification reliability, as is shown, for example, in said U.S. Pat. No. 5,262,784. The MMI according to the invention displays both aircraft positions and other information superimposed, both in the respectively appropriate form, that is to say, for example, as raw video, as processed video, obtained optically or by radar, and directly or alphanumerically.
Details or sections from displays, switching states, positions etc. can advantageously be displayed enlarged (zoomed). For example, the precise positions of aircraft and, possibly, vehicles can advantageously be indicated in relation to individual lights, stop bars, sensors etc. The zoomed—and possibly also reduced—displays can optionally be arranged on free areas, or superimposed on the basic image.
The invention also allows aircraft and vehicles to be displayed on the basis of their current position on the movement areas, with an identification of the responsibility for the aircraft or vehicle. In consequence, task allocation is immediately evident, particularly at larger airports where a number of controllers are responsible for traffic management at the airport. The display of the responsibility for the aircraft or vehicle is advantageously linked to handover routines for a change in responsibility, for example in list form, for which purpose confirmation annotations, and corresponding list changes may be provided on the screen.
It is particularly advantageous to display routes planned by a computer facility, to avoid collisions and to have the capability to switch and display such routes, possibly also automatically. Corresponding procedures are evident from the already mentioned U.S. Pat. No. 5,374,932.
Specific position signals on the screen, for example “stop bar crossed”, in this case improve safety, as does direct flight plan processing on the MMI. Filters for masking out information which is irrelevant at the moment, for example in the apron area or in the local control area, further improve the safety of traffic management using the MMI.
As a rule, control functions are normally separated at large airports, with handovers to other responsibility areas. The large screen according to the invention now allows just one controller to handle the traffic, particularly at times when traffic levels are low, by superimposing and/or successively displaying different charts or maps, for example of the airport layout, of zoomed sections, of the coordinate system, as well as of the areas which are open and closed to traffic, of the recommended routes, of the associated lists, and video displays of the docking process etc. As the traffic level increases, the monitoring and control work is then transferred to a number of controller positions.
In addition to the control functions, the invention advantageously allows the synthetic videos and charts or maps to be changed to match the task and/or level or authorization. The invention furthermore makes it possible to carry out save operations matched to the task and to output various configurations of the displays in conjunction with a computer unit. The MMI can thus advantageously be matched to different circumstances at the airport, to changed routines, routine sequences etc., with direct control of the results of the change. Thus, all the process steps required to operate an airport, even a large airport, can be carried out, following the initial installation of the computer unit and its software, on the MMI according to the invention.
Important additional information can also be displayed on the MMI according to the invention, since a large display area (which has never been used in the past) is available. Such information may include, for example, weather reports (for example the wind direction, the wind speed, etc.) as well as visibility details and other weather information.
The main work screen according to the invention can, of course, be connected to other screens, for example to screens showing details from air traffic control centers, in order to allow the traffic to be planned in advance. Such details from an additional screen may also, of course, be displayed on the main screen, for example in a corner. This results, overall, in the capability to display on one screen all the information required for operational traffic management at a large airport.
The individual superimposed displays, which are each required only for a specific time period, are possibly advantageously canceled again after a predetermined time, in order to revert to the basic state again. The image is then advantageously built up again from this basic state in the particular form required, depending on the situation.
It is also particularly advantageous to display an alarm signal, preferably in red or yellow, providing information about special situations. A list presentation can possibly also be used for this purpose, from which the individual times can be seen when special situations occur, together with the urgency for action on them and their action status.
The MMI can have touch elements and/or, at least on parts of a frame or a console, switches for operating, supplementing and/or producing redundancy for the signals emitted by switching (touch) elements. Producing redundancy is particularly important, since airports are subject to very stringent safety requirements. Touch or switching elements which are located in the controller's normal field of view are particularly suitable for this purpose, since they prevent the controller from having to interrupt his visual monitoring of the airfield, the taxiways etc. at any time.
The MMI screen is advantageously a plasma screen or gas-discharge screen, although it can likewise be an LCD screen with background lighting or an LED screen. Any of these techniques can be used to produce a large screen, with the plasma screen having the best resolution. Suitable plasma screens with particularly advantageous screen sizes of more than 100 cm are already known from the field of television. In this case, a touch screen can be designed such that sensitive coverings are arranged over the actual screen, for example in conjunction with a glass panel or a plastic sheet.
If the screen is designed to be very large, it is particularly advantageous to use a projection screen, for example a screen with laser projection. The superimposed displays according to the invention can then be produced particularly easily and brilliantly.
Despite its size, the screen is advantageously arranged in the controller's normal field of view, and it is advantageous for the screen to be arranged at a considerable angle to the vertical, with the angle being variable depending on the situation. In consequence, any adverse effect on the controller's field of view is acceptable. The oblique arrangement is assisted by the flat screen configuration, advantageously with the angle at which it is positioned depending on the time of day.
For particular requirements in a tower, ceiling fitting is also possible, in which case keyboard/mouse control is chosen. Nonreflective coatings are provided to prevent disturbing reflections. Electromagnetic radiation shielding is also provided.
For use in countries where English is not normally spoken, it is particularly advantageous for the MMI to provide multilingual details of the individual names, terms in use etc. The MMI is thus connected to a word memory, which contains details in various languages. In this case, it is particularly advantageous to have two configurations: one in the national language and one in the language of the manufacturer who will also carry out the maintenance work, so that his personnel can work in their own national language, with English as the general language for aviation.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention and further advantageous refinements of the invention according to the features of the dependent claims are explained in more detail below with the aid of diagrammatic, exemplary embodiments in the drawing, in which:
FIG. 1 shows an example of a display of a simple runway with taxiways and an apron area,
FIG. 2 shows an example of the switching state of the lighting before taxiing clearance,
FIG. 3 shows an example of the switching state of the lighting after taxiing clearance,
FIG. 4 shows an example of the switching state of the lighting and stop bars at the end of the runway when traffic is dense,
FIG. 5 shows an overview of the major information provided,
FIG. 6 shows a large-format map of a large airport,
FIG. 7 shows a window display of the large airport from FIG. 6 and a detail enlargement, both with aircraft positions,
FIG. 8 shows a zoom display of detail enlargement from FIG. 7,
FIG. 9 shows an overview of a relatively small airport with control function blocks,
FIG. 10 shows an enlarged display of the airport from FIG. 9 with selective details,
FIG. 11 shows a zoom display of the lighting at the airport from FIG. 10, and
FIGS. 12 to 14 show a superimposed display of the individual runway lights with section details from the map of a relatively small airport.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, 1 denotes a runway and 2 a taxiway. Switchable center lights 5 and other flush lights 4 are arranged in the runway 1 and can be designed to emit both white and red light, or possibly green light. There is also a row of lights 3 in the runway, which is designed, for example, to illuminate in red. This row of lights may possibly give take-off clearance. The taxiway 2 likewise has center lights 6 , which may emit various colors. In the apron area 7 , there are other lights, which are not marked in any more detail and some of which have signal functions. Lights without signal functions are not shown. At times, there are aircraft on the runway 1 and on the taxiway 2 , whose position is denoted, by way of example, by crosses 8 and 9 . While both the display of the runway and taxiways, as well as the display of the buildings and, possibly, of the airport environment (which are not shown here) are fixed inputs for the display, the positions 8 and 9 of the aircraft originate from a radar video, which is advantageously superimposed on the display of the airport. Position areas in which aircraft are located can also, of course, be determined by sensors which are installed by the taxiways etc.
In FIG. 2, 10 denotes an aircraft prior to taxiing, and 11 flush lights which are illuminated in red for the pilot. The flush lights 12 are illuminated in green, as is the flush light 13 . The flush lights 14 are illuminated in white, while the flush light 15 is illuminated in green and the flush light 16 is illuminated in green on one side and in white on the other side.
FIG. 3 shows the signal state of the flush lights after taxiing clearance, and the pilot in the aircraft 10 sees each of the lights 13 , 14 , 15 and 16 as green, while the lights 11 are not illuminated. This results in clear signaling to the pilot in the aircraft 10 that the taxiing process can commence, and the signaling can be monitored on the screen.
In FIG. 4, 20 denotes an aircraft at the end of the runway, and 21 denotes another aircraft on a taxiway. On the various taxiways, the taxiway center lights are in each case illuminated in green, for example in sections, in lines 22 , 23 and 24 , as required. They thus tell the pilots the route they must take. At the end of the individual interconnected rows, there are, for example, stop bars 26 , 27 and 28 , which indicate in red to the pilots that they may taxi only as far as this point.
Furthermore, there are no-entry notices 25 , possibly in the end section of the runway shown, with the taxiways adjacent to it, which no-entry notices 25 are likewise illuminated, and sensors 29 are located on the entry side, and their details can supplement or replace radar displays. Such sensors are preferably designed as microwave sensors and may allow or control block-by-block switching of flush lights, as is known for signals for railroad traffic.
The above figures show a number of examples for safe taxiing on the ground, in a way which can be monitored and carried out according to the invention by means of large flat screens. In this case, the known control panels have been replaced by a model of the airport geography, and with a large number of switches. Known control panels operated with optical conductors or individual diodes, and possibly with small incandescent bulbs as well. It is not possible for any radar videos or additional information about the traffic situation at an airport to be transferred to such facilities. However, this is possible according to the invention by virtue of the large display areas, which are advantageous, in particular, in conjunction with interactive screens, such as touch screens or the like.
In FIG. 5, the major details contained in the synthetic video are listed at 30 . The details from the radar video are advantageously superimposed on the synthetic video, so that the actual information about the position of aircraft and/or possibly vehicles can be seen from the synthetic video. 31 shows the two types of sensors, which can operate on a very different basis. Most important are the interactively operating sensors which at the same time verify the aircraft identification, for example by means of transponders. 32 shows the basic routes for the traffic management system on the ground and in the air in order to provide aircraft with safe instructions, guaranteeing a smooth traffic flow. 33 shows auxiliary functions which are important particularly in the event of any special occurrences. 34 shows the major components for management of the aircraft on the runway and the taxiways, and in the apron area, while 36 shows the docking automation, which can be carried out using a very wide range of sensors, preferably with line-scan cameras, which use pattern comparison, or alternatively using lasers, microwave receivers etc., possibly with support from D-GPS etc. Finally, 35 shows the integration of the widely different types of data which flow together in the system and can be displayed on the screen together with the information from 30 , 32 , 34 and 36 . The sensor information includes the radar information, of course, the main information source at an airport.
It is self-evident that the system according to the invention is still used even if all the individual components described here are not integrated in the system but are operated as stand-alone systems, or if individual components, such as automatic docking systems, do not exist at all, for example at relatively small airports with only a few parking positions. The basis of integrated control of aircraft and, possibly, vehicles remains as the solution according to the invention.
In FIG. 6, the overall view of a large airport, 36 and 37 denote the runways, and 38 the actual airport buildings in the center between the runways and the taxiways, which are associated with the runways but are not shown in any more detail. This overall view is used for clarity and, in particular, to choose the zoom sections.
In FIG. 7, 39 denotes a window, in this case arranged in the top left-hand corner of the screen, with a highly scaled-down illustration of the airport from FIG. 6 . The window also includes an area for clicking on the various work functions using a mouse. Superimposed displays of aircraft positions with further details can also be superimposed in the window 39 ; such advantages are perfectly feasible on a large screen, owing to the clearer legibility. Alongside the window 39 there is an enlarged display 41 of a runway-taxiway section, with superimposed aircraft position details 42 and 43 . This display makes it easier to select further zoom displays than in the window 39 .
Finally, FIG. 8 shows the zoom display of an aircraft position, with identification details being provided for the aircraft. The position of the aircraft is represented by a dot 44 , on which an area with after-glow can be superimposed. This makes it easier to follow the movement of the aircraft. The details about which aircraft this is may, as can be seen, be on one line, or else may be increased up to three lines. All the relevant information relating to an aircraft, such as the aircraft type, flight number, callsign etc. can then be displayed, or alternatively airport-specific data, such as the gate number and the category to which the aircraft must be allocated.
FIG. 9 shows a schematic view of an airport map for a relatively small airport. The display and the control windows are designed to allow touch control. The display may be in the national language, in English or in any other desired language. The airport has only one runway 45 . The other aeronautically important details can be seen on the display.
The display in FIG. 10 now shows a greater resolution and has control buttons which allow the individual runway parts and taxiways to be selected. The two runway parts are denoted by 45 and 47 , and correspond to the details for the runway 16 and runway 34 on the control buttons. The stop bars are denoted by ST 1 to ST 5 . Once again, zooming to control the individual lights is possible with this display, as is shown, by way of example, in FIG. 11 . The individual fights are denoted by 48 in FIG. 11 . The corresponding enlargement also clearly shows the individual switching state of the lights. A superimposed display of an aircraft is possible.
Finally, FIGS. 12 to 14 show enlarged (zoomed) details of a small airport, whose basic configuration can be seen from the superimposed image at the foot of the zoomed display. In order to show the precise position of the respective section, the zoomed display shows a plan of the airport with details of the zoom section. FIG. 12 thus shows a zoom section 49 with the switching display for the individual lights, FIG. 13 shows the zoom section 50 , likewise with an enlarged display of the individual lights, and FIG. 14 shows the zoom section 51 , likewise with an enlarged display of the individual lights. The respective switching state, a failure etc., can also be seen from the enlarged display of the individual lights in FIGS. 12 to 14 . Superimposition of the aircraft position in the sections 49 , 50 and 51 , which are illustrated here only by way of example, is particularly advantageous. There are other sections, which are not shown in detail, between the illustrated sections.
Irrespective of whether the airport is small, relatively large or even large, the MMI according to the invention is able to supply all the information required for operational management of an airport in a form which provides complete information safety. Although tower controllers have been able to work well with the previous, relatively small screens, it has been found surprisingly that a considerable enlargement of the screen size and, in particular, a configuration as a flat screen, makes it possible to achieve a further improvement in safety, an improvement in taxiing control, and better operational management of an airport overall. One precondition for this is, in particular, the superimposition of the various information items required on a relatively large area, which the MMI makes possible in conventional form by known technologies (windows and menu control), preferably using Windows NT and radar video generation, which can be carried out based on the method used by the Company HITT, in Holland.
The above description of the preferred embodiments has been given by way of example. From the disclosure given, those skilled in the art will not only understand the present invention and its attendant advantages, but will also find apparent various changes and modifications to the structures disclosed. It is sought, therefore, to cover all such changes and modifications as fall within the spirit and scope of the invention, as defined by the appended claims, and equivalents thereof. | Man-machine interface (MMI) for airport traffic control purposes, in particular for safe taxiing and/or approach-departure control at an airport, having a display area on which processes and states at the airport, for example the movements and the current position of aircraft, the switching state of lighting systems, etc., can be displayed and influenced. The display area is designed with a screen whose diagonal is more than 19 inches, preferably more than 21 inches. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation-in-part of U.S. patent application Ser. No. 09/501,114, filed Feb. 10, 2000, and claims priority to the U.S. Provisional Patent Application No. 60/119,771, filed Feb. 10, 1999, both of which are incorporated herein by reference in their entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] The U.S. government has a paid-up license in this disclosure and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of United States National Aeronautics and Space Administration (Contract No. NASA/NCC5-165) and the United States Department of the Navy (Contract No. Navy/N00014-98-1-0571).
FIELD OF THE INVENTION
[0003] The present disclosure relates to a method of synthesizing diamond. In particular, the present disclosure relates to a method of synthesizing diamond crystals and diamond films using plasma enhanced chemical vapor deposition.
BACKGROUND
[0004] Diamond synthesized by chemical vapor deposition (“CVD”) has many unique and outstanding properties that make it an ideal material for a broad range of scientific and technological applications. A number of methods for diamond CVD are reported which utilize various gas mixtures and energy sources for dissociating the gas mixture. Such methods include the use of high temperature electrons in various kinds of plasma, high solid surfaces on hot filaments, and high temperature gases in combustion flames to dissociate molecules such as hydrogen, oxygen, halogen, hydrocarbon, and other carbon containing gases. Typically, a diamond crystal or film is grown on a substrate, which is usually maintained at a temperature much lower than that of electrons in the plasma, the heated surface of a hot filament, or the combustion flame. As a result, a super equilibrium of atomic hydrogen is developed near the diamond growing surface of the substrate.
[0005] Atomic hydrogen is believed to be crucial in the diamond CVD process. It is theorized that atomic hydrogen is effective in stabilizing the diamond growing surface and promoting diamond growth at a CVD temperature and pressure that otherwise thermodynamically favor graphite growth. Consistently, the reported diamond CVD processes involve the use of hydrogen gas or hydrogen containing molecules. The most typical diamond CVD process utilizes a precursor comprising of methane gas diluted by 94-99% hydrogen. With these CVD processes, the super equilibrium of atomic hydrogen can be achieved at a varied percentage of molecular hydrogen in the gas mixture. However, these CVD processes depend on the effectiveness of the dissociation process in generating atomic hydrogen.
[0006] Using a high power density microwave plasma to deposit diamond in a precursor comprising of a mixture of methane and hydrogen with less than 50% hydrogen has been reported. Growth of diamond from oxy-acetylene flames utilizes a precursor comprising acetylene and oxygen with a ratio of acetylene to oxygen slightly greater than 1 without additional molecular hydrogen being added. Diamond is deposited in the reducing “inner flame” where atomic hydrogen is a burn product produced by the high temperature flame. In addition to atomic hydrogen, there are plenty of OH radicals present near the diamond growing surface inside the flame.
[0007] OH and O radicals can play another role of atomic hydrogen in the diamond growth process. That is, preferential etching of non-diamond carbon, which results in a net deposition of high purity diamond. A small quantity of oxygen (0.5-2%) and/or water vapor (<6%) added to the methane and hydrogen precursor is reported to improve diamond crystallinity and lower the diamond CVD temperature. The quantity, whether small or large, of oxygen and/or water in a precursor or feedstock is a relative term depending on many other process parameters. Diamond has also been grown in a microwave plasma of a precursor comprising an acetone/oxygen mixture with a molecular ratio near 1:1.
[0008] Most of the diamond CVD processes involve the use of one or more compressed gases. Typically, such CVD processes utilize a compressed gas precursor comprising 1 vol % methane gas diluted by 99 vol % hydrogen. These gases usually must be precisely controlled by electronic mass flow controllers to ensure the accurate composition in the gas precursor feed.
[0009] In U.S. Pat. No. 5,480,686 to Rudder et al. (“Rudder”) a method of diamond growth is disclosed that utilizes a radio frequency (“RF”) plasma in a precursor comprising a mixture of water (more than 40%) and alcohol. No compressed gases are needed for this diamond CVD process. However, water has a low vapor pressure at room temperature, and condensation of water in the cooler part of the reactor manifold may be a concern. Also, water has a high freezing temperature making it easy to freeze at the orifice of a flow controller where liquid vaporizes and enters a low pressure reactor chamber. Buck et al. (“Buck”), (“Microwave CVD of diamond using methanol-rare gas mixtures,” Materials Research Society Symposium Proceedings, Vol. 162, 97-102, 1989.) have grown clusters of diamond crystallites on small (2-4 mm 2 ) silicon substrates that were scratched with a diamond tip or mechanically polished with 3 μm diamond powder by microwave plasma enhanced CVD in pure methanol vapor. Argon gas additive was found necessary for high quality diamond to be deposited in the methanol vapor. When it is fully dissociated and reacted in the plasma, the pure methanol vapor plasma contains a C/O/H composition similar to that of CO/H 2 plasma, which has been used for successful deposition of diamond by means of electrical discharges.
[0010] In a typical electrical discharge such as a microwave plasma, electrons with an average temperature exceeding 10,000° C. are abundant. These energetic electrons effectively dissociate molecular species and generate a high concentration of radicals necessary for the deposition of diamond and the preferential etching of non-diamond deposits without needing a high temperature filament. Hot filament assisted CVD processes employ solid surfaces at a temperature of about 2,000° C.-2,500° C. to dissociate molecules and generate radicals necessary for diamond deposition. The hot filament temperature is much lower than that of energetic electrons in a plasma. As a consequence, hot-filament CVD of diamond in CO/H 2 mixtures has not been successful even though the same gas mixtures have been routinely used for plasma assisted deposition of diamond films.
[0011] Nevertheless, the plasma enhanced CVD method is desirable because diamond crystals and films can be deposited on large-area and/or irregularly shaped objects using inexpensive equipment. Thus, there remains a need for an economic method of synthesizing diamond utilizing plasma enhanced CVD.
SUMMARY
[0012] Briefly described, methods of forming diamond are described. A representative method, among others, includes: providing a substrate in a reaction chamber in a non-magnetic-field microwave plasma system; introducing, in the absence of a gas stream, a liquid precursor substantially free of water and containing methanol and at least one carbon and oxygen containing compound having a carbon to oxygen ratio greater than one, into an inlet of the reaction chamber; vaporizing the liquid precursor; and subjecting the vaporized precursor, in the absence of a carrier gas and in the absence in a reactive gas, to a plasma under conditions effective to disassociate the vaporized precursor and promote diamond growth on the substrate in a pressure range from about 70 to 130 Torr.
[0013] Another representative method of forming diamond includes: providing a substrate in a reaction chamber in a non-magnetic-field microwave plasma system, the reaction chamber being in fluidic communication with a container through a metering valve, wherein the container includes a liquid precursor substantially free of water containing methanol and at least one carbon and oxygen containing compound having a carbon to oxygen ratio greater than one; flowing the liquid precursor into the reaction chamber using the metering valve, in the absence of a gas stream flowing through the metering valve entraining the liquid precursor, wherein the liquid precursor vaporizes during entry into the reaction chamber; vaporizing the liquid precursor; subjecting the vaporized precursor to a plasma under conditions effective to disassociate the vaporized precursor in the absence of a carrier gas and in the absence in a reactive gas; and promoting diamond growth on the substrate at a pressure in the range from about 10 to 130 Torr.
[0014] Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings 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 present disclosure, and be protected by the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Many aspects of this disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention.
[0016] [0016]FIG. 1 is a schematic illustration of a microwave plasma enhanced chemical vapor deposition system made in accordance with the present disclosure.
DETAILED DESCRIPTION
[0017] For a more complete understanding of the present disclosure, reference should be made to the following detailed description taken in connection with the accompanying figure.
[0018] The present disclosure relates to systems and methods of synthesizing diamond (e.g., crystals and/or diamond films) for a very broad range of scientific and technological applications such as optical windows, machining tools, heat spreaders, tribological coatings, sensors and actuators, electrochemical coatings, protective coatings, and wide-bandgap semiconductor devices. The systems and methods use a non-magnetic-field microwave plasma system. The systems and methods of the present disclosure use a premixed methanol-based liquid solution as the feedstock (e.g., precursor liquid). The methanol-based solution contains one or more carbon containing compounds with the molar ratio of atomic carbon to atomic oxygen being greater than one. The methanol-based solution includes methanol from about 50 to 96% by weight of the feedstock and is substantially free of water. The feedstock is introduced, in the absence of a gas stream entraining the feedstock, to a reaction chamber. Then, the feedstock is vaporized and subjected to a plasma, in the absence of a carrier gas (e.g., Argon) or a reactive gas (e.g., H 2 ), under conditions effective to disassociate the vaporized feedstock to promote diamond growth on a substrate. The pressure range for the system can be from about 10 to 130 Torr and from about 70 to 130 Torr.
[0019] [0019]FIG. 1 generally illustrates the plasma enhanced chemical vapor deposition system utilized in performing the methods of the present disclosure. As illustrated in FIG. 1, the precursor 5 is fed from a precursor container 4 by a conduit 6 , such as a TEFLON or metal tubing, through a metering valve 7 , such as a needle valve, to an inlet 2 of reactor chamber 1 in the absence of a gas stream.
[0020] The reactor chamber 1 is formed from a material capable of withstanding the temperature generated during the CVD process. In particular, the reactor chamber 1 is stainless steel and typically 8″ in diameter. When the liquid precursor 5 enters the low pressure side of the metering valve 7 within the reactor chamber 1 , it vaporizes to form a vapor precursor comprising a mixture with the same molar composition as the liquid precursor 5 .
[0021] In addition to inlet 2 , the reactor chamber 1 has an outlet 3 connected to a mechanical vacuum pump 13 through an automatically controlled throttle valve 14 to maintain constant pressure in the reaction chamber 1 throughout the deposition process and for circulating the vapor of the liquid precursor 5 through the reactor chamber 1 . The vapor precursor is maintained at a pressure within the vacuum chamber 1 from about 10 Torr and 130 Torr, about 50 to 130 Torr, about 70 to 130 Torr, about 80 to 130 Torr, and, preferably 110 to 130 Torr, with the pressure being monitored by a pressure gauge (not shown).
[0022] The metering valve 7 can include a temperature measuring device (e.g., a thermocouple) coupled to the tip of the metering valve 7 . The vaporization of the liquid precursor 5 causes the metering valve 7 to decrease in temperature to a temperature value. The temperature value is correlated to a flow rate of the liquid precursor 5 , which in turn corresponds to a pressure in the reaction chamber 1 under constant conditions. Therefore, opening the metering valve 7 to an extent so that a known temperature value is obtained can substantially reproduce the corresponding flow rate of the liquid precursor 5 into the reaction chamber 1 .
[0023] In one embodiment, the liquid precursor 5 can be disposed in a container, at atmospheric pressure. The liquid precursor 5 in the container can be replenished during the formation of the diamond without interrupting the formation.
[0024] In another embodiment, the container can be disposed within the system. In this regard, the liquid precursor 5 evaporates within the system to provide precursor vapor to form the diamond. The liquid precursor 5 can be replenished during the formation of the diamond without interrupting the formation.
[0025] Electromagnetic energy 8 discharged at various frequencies, for example, DC, RF, and microwave, and also high frequency electromagnetic energy such as energy discharged from a laser, is applied to the reactor chamber 1 . A window 9 , such as a quartz window, separates the low pressure reactor from ambient pressure and permits microwave energy to propagate into the reaction chamber 1 . Preferably, the electromagnetic energy 8 is microwave energy. The reactor chamber 1 is a part of the cylindrical cavity for the microwave of 2.45 GHz.
[0026] A substrate 11 is placed on a substrate holder 12 , preferably a water-cooled substrate holder to control the temperature of and cool the substrate 11 . The substrate 11 temperature is monitored with a dual color optical pyrometer (not shown). The vaporized precursor liquid passes across the substrate surface 15 , in the absence of a carrier gas such as hydrogen (H 2 ), where the plasma 10 dissociates the vapor precursor and releases OH, H, O, CH 3 , CH 2 , etc. radicals for a net deposition of diamond on a substrate surface 15 .
[0027] Methanol vapor (CH 3 OH) has a carbon to oxygen ratio equal to one. In the present disclosure, when methanol dissociates, it forms high concentrations of radicals that rapidly etch carbon, including diamond, resulting in slow growth of diamond in areas where a diamond deposition rate exceeds the etching rate. The growth rate and degree of non-uniformity also depend on the exposure of carbon, which may be present in some reactor fixtures or previously coated on reactor walls or the substrate holder, to the methanol plasma.
[0028] When the liquid precursor 5 comprises a solution of methanol and a known quantity of one or more carbon containing compounds having a carbon to oxygen ratio greater than one, diamond growth is substantially uniform, reproducible, and at a higher growth rate than with conventional CVD methods.
[0029] The carbon containing compound can include, but is not limited to, ethanol (CH 3 CH 2 OH), isopropanol ((CH 3 ) 2 CHOH), and acetone (CH 3 COCH 3 ), which have respective carbon to oxygen ratios of 2, 3, and 3. The selection of the carbon containing compound is not limited to ethanol, isopropanol, or acetone, and may be selected from other such carbon containing compounds having carbon to oxygen ratios greater than one.
[0030] The feedstock can include methanol in amounts of about 50 to 96 weight percent of the feedstock, about 73 to 96 weight percent of the feedstock, and, preferably about 90 to 96 weight percent of the feedstock. The remaining portion of the feedstock includes one or more carbon containing compounds as described above. In particular, the feedstock can include ethanol, isopropanol, acetone, or combinations thereof, in an amount from about 4 to 50 weight percent of the feedstock, about 4 to 27 weight percent of the feedstock, and, preferably about 4 to 10 weight percent of the feedstock. Exemplary feedstock compositions and ratios of the components are described in Table 1.
[0031] If the precursor comprises only a carbon containing compound having carbon to oxygen ratios greater than one, suppression of the formation of non-diamond phases can generally be maintained by lowering the substrate temperature to below about 900° C. and/or selectively neucleating the substrate with high quality diamond particles. Also, diamond growth is also a function of the plasma density, reaction chamber pressure, carbon to oxygen ratio at the substrate surface, and precursor flow rate, and these functions are monitored and adjusted accordingly to promote diamond growth.
[0032] Furthermore, if it is desired for the diamond to contain a dopant, the carbon containing compound can include dopant elements or moieties in addition to C, O, and H, such as, but not limited to, boron, phosphorus, silicon, etc. Such dopants include, but are not limited to, halides, metals, and the like.
[0033] The substrate can include materials conventionally utilized in CVD processes. Useful substrate materials are capable of withstanding the temperatures generated during the plasma process. Examples of such substrates include, but are not limited to, a sheet or wafer of silicon, copper, aluminum, molybdenum, and alloys thereof. Further, the substrate may be either unseeded or seeded with diamond crystallites. Seeding can be accomplished by polishing the diamond-growing surface of the substrate with diamond paste containing diamond particles, such as 1 μm particles. It should be noted that diamond crystallites could be grown on aluminum at temperatures below that of the melting point of aluminum (e.g., Example 4 in Table 1). Also, diamond crystallites can be grown without seeding, which is difficult to do using other chemical vapor deposition systems (e.g., Examples 5 and 8 in Table 1).
[0034] In experiments conducted using the systems and methods of the present disclosure, the deposition process lasted for about 2 to 100 hours resulting in diamond films with well faceted diamond grains clearly visible using an optical microscope. The diamond grain sizes range from sub-micrometers to more than 500 μm.
[0035] An electromagnetic, such as microwave, plasma enhanced chemical vapor deposition technique using a precursor including methanol-based solutions as described above has been developed for the deposition of diamond. The OH, H, O radicals generated by the dissociation of the precursor vapor are shown to be sufficient in suppressing the growth of graphitic and amorphous carbon, which results in the net deposition of diamond by the carbon containing radicals that were dissociated from the same vapor. By the addition of carbon containing compounds having a carbon to oxygen ratio greater than one, to methanol, the diamond growth rate increases by orders of magnitude over that without the compound additives.
[0036] The aforementioned precursors are less costly than the typical compressed gases that are often used for diamond deposition. The precursors are much safer than the explosive gas mixtures containing a large proportion of hydrogen that are used by conventional diamond CVD deposition processes. Further, the mixing of a methanol-based solution can be performed under standard conditions (e.g., temperature and pressure) without the need for an expensive precision electronic mass flow controller.
EXAMPLES
[0037] A. Substrate Pre-Treatment and Cleaning.
[0038] Substrates of silicon, aluminum, and molybdenum were cleaned by acetone and methanol before being loaded onto the substrate holder. Only Examples 5 and 7 were not polished with diamond paste containing 1 μm sized diamond particles.
[0039] B. Deposition Parameters.
[0040] Typical deposition parameters are as follows:
Microwave power about 600-3000 W Vapor pressure about 10-130 Torr Substrate temperature about 300° C.-1600° C. Methanol about 50-96% by weight Ethanol, isopropanol, and acetone about 4-50% by weight
[0041] C. Diamond Film Characterization Methods.
[0042] A Normaski phase contrast optical microscope was used to examine the crystal shapes and surface morphology of the deposited films. Diamond grains with (100) or (111) facets can clearly be seen using this optical microscope. The diamond film thickness can also be measured by examining the cross-sectional view of such films using the same optical microscope. A micro Raman spectrometer powered by an Argon ion laser was used to examine the phase purity of the deposited films. Diamond peak around 1332 cm −1 provided convincing evidence that the deposited carbon films were high-quality diamond.
[0043] D. Example Precursor Liquids
[0044] Table 1 provides exemplary examples to illustrate embodiments of the present disclosure but are not to be construed as limiting the scope of the present disclosure in any way.
[0045] Although this disclosure has been described in detail for the purpose of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention which is defined by the following claims. | Briefly described, methods of forming diamond are described. A representative method, among others, includes: providing a substrate in a reaction chamber in a non-magnetic-field microwave plasma system; introducing, in the absence of a gas stream, a liquid precursor substantially free of water and containing methanol and at least one carbon and oxygen containing compound having a carbon to oxygen ratio greater than one, into an inlet of the reaction chamber; vaporizing the liquid precursor; and subjecting the vaporized precursor, in the absence of a carrier gas and in the absence in a reactive gas, to a plasma under conditions effective to disassociate the vaporized precursor and promote diamond growth on the substrate in a pressure range from about 70 to 130 Torr. | 2 |
TECHNICAL FIELD OF INVENTION
[0001] This disclosure generally relates to a liquid cooled power electronics assembly, and more particularly relates to an assembly that uses dielectric plates attached to an electronic device and a metallic seal along the perimeter of the plates to protect the electronic device from contamination or operational interference by electrically conductive coolant such as automotive engine coolant.
BACKGROUND OF INVENTION
[0002] It is a continuing desire to increase power dissipation ratings of electronics, and put those electronics into smaller packages. One industry where this is especially true is the transportation industry, especially in view of the advent of electric or hybrid automobiles. Such automobiles are propelled, all or in-part, by electric motors that rely on transistors and other devices to switch electrical power to the electric motors. The power controlled by these transistors may have voltage potentials ranging from 100 Volts to 2400 Volts, and may switch currants range from 50 Amperes to 600 Amperes. Any increase in the efficiency by which heat is removed from transistors can increase the reliability or power rating of the electronics.
SUMMARY OF THE INVENTION
[0003] In accordance with one embodiment, a liquid cooled power electronics assembly is provided. The assembly is configured to tolerate the use of electrically conductive coolant to cool power electronic devices. The assembly includes a housing, an electronic device, a lead frame, a first dielectric plate, a second dielectric plate, a first metallic seal and a second metallic seal. The housing is configured to define an inlet, an outlet, and a cavity configured to contain coolant within the cavity between the inlet and the outlet. The electronic device is located within the cavity. The electronic device is characterized as being substantially planar in shape and so defines a first planar side, a second planar side opposite the first planar side, and a device perimeter between the first planar side and the second planar side. The lead frame is electrically coupled to the electronic device and extends outside the cavity through an opening in the housing. The first dielectric plate is attached to the first planar side. The first dielectric plate has a first plate perimeter that extends beyond at least a portion of the device perimeter. The second dielectric plate is attached to the second planar side. The second dielectric plate has a second plate perimeter that extends beyond at least a corresponding portion of the device perimeter. The first metallic seal is formed between the portion of the first plate perimeter and the corresponding portion of the second plate perimeter. The first metallic seal is effective to isolate the electronic device from the coolant. The first dielectric plate, the second dielectric plate, and the first metallic seal cooperate to form a device package. The second metallic seal is formed between the device package and the opening effective to prevent coolant from passing out of the cavity through the opening.
[0004] Further features and advantages will appear more clearly on a reading of the following detailed description of the preferred embodiment, which is given by way of non-limiting example only and with reference to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0005] The present invention will now be described, by way of example with reference to the accompanying drawings, in which:
[0006] FIG. 1 is a cutaway perspective view of a liquid cooled power electronics assembly in accordance with one embodiment;
[0007] FIG. 2A is a perspective view of a partially assembled device package used in the assembly of FIG. 1 in accordance with one embodiment;
[0008] FIG. 2B is a perspective view of a fully assembled device package used in the assembly of FIG. 1 in accordance with one embodiment;
[0009] FIG. 3 is a perspective view of a combination lead frame/perimeter frame optionally used in the device package of FIG. 2B in accordance with one embodiment;
[0010] FIG. 4 is a perspective view of a device package used in the assembly of FIG. 1 in accordance with one embodiment;
[0011] FIG. 5 is a perspective view of part of the assembly of FIG. 1 in accordance with one embodiment;
[0012] FIG. 6 is a device package used in the assembly of FIG. 1 in accordance with one embodiment; and
[0013] FIG. 7 is a device package used in the assembly of FIG. 1 in accordance with one embodiment.
DETAILED DESCRIPTION
[0014] FIG. 1 illustrates a non-limiting example of a liquid cooled power electronics assembly, hereafter the assembly 10 . In general, the assembly 10 described herein is a sealed electronics assembly that immersion cools a power dissipating electronic device 12 ( FIG. 2 ) that is inside a device package 14 with coolant 16 , such as a mixture that includes water and ethylene glycol. It should be appreciated that such water-based coolant may be electrically conductive, and so the assembly 10 described herein must sufficiently isolate the electronic device 12 from the coolant 16 in order to prevent electrical shorting or unexpected operation of the electronic device 12 . It should also be appreciated that it is not a requirement that the coolant 16 be electrically conductive, and so a non-electrically-conductive coolant would be suitable if it has adequate heat transfer characteristics.
[0015] The assembly 10 generally includes a housing 18 . The housing 18 may be formed of polymeric material such as a glass gilled nylon marketed as Zytel™ by Dupont (part number 70G25HSLR BK099), or may be formed of metal such as aluminum. The housing 18 may include an inlet 20 and an outlet 22 configured to make a fluidic sealed connection to, for example, hoses (not shown) providing a fluidic connection to a heat exchanger (not show) that transfers heat from the coolant to, for example, ambient air. In general, the inlet 20 receives relatively lower temperature coolant for the assembly 10 , and the outlet 22 removes coolant warmed by power dissipated by the electronic device 12 . The housing 18 also generally defines a cavity 24 inside the housing 18 that contains the coolant 16 as it passes from the inlet 20 to the outlet 22 . The size and shape of the cavity 24 , the inlet 20 , and the outlet 22 are determined based on the number and size of the device package 14 , the amount of power dissipated by the device package 14 , and expected coolant inlet temperatures using know engineering rules and design practices.
[0016] FIGS. 2A and 2B illustrate a device package 14 that is partially assembled and fully assembled, respectively. The electronic device 12 is typically a wafer level device, meaning that the electronic device 12 is generally described as unpackaged, typically with exposed surfaces of silicon, passivation, or thin film metallization. The electronic device 12 may be a solid state electronic switch such as a transistor, for example, a metal oxide semi-conductor field effect transistor (MOSFET), or insulated gate bipolar transistor (IGBT), or a diode. By way of example and not limitation, a typical electronic device is formed predominately of silicon having dimensions of 12 millimeters (mm) by 12 mm by 0.075 mm. The electronic device 12 may be generally characterized as being substantially planar in shape, and so generally defines a first planar side 26 (not specifically shown), and a second planar side 28 opposite the first planar side 26 . The planar shape of the electronic device 12 may also generally define a device perimeter 30 , or edge, between the first planar side 26 and the second planar side 28 .
[0017] The device package 14 may also include a first dielectric plate 32 attached to the first planar side 26 . The first dielectric plate 32 generally defines a first plate perimeter 34 that extends beyond at least a portion of the device perimeter 30 . The first dielectric plate 32 is preferably a ceramic material, for example aluminum nitride, aluminum oxide, or silicon dioxide. Ceramic material is preferred because the coefficient of thermal expansion (CTE) typically more closely matches that of the electronic device 12 , and so is believed to generally improve the reliability of the attachment of the first dielectric plate 32 to the electronic device 12 . As the outer surface of the device package 14 will be exposed to the coolant 16 , ceramic based materials are also an excellent choice as they are generally impervious to fluids that may be used as the coolant 16 . By way of example and not limitation, suitable dimensions for the first dielectric plate 32 for the typical electronic device suggested above are 28 mm by 20 mm by 2 mm. If the first dielectric plate 32 is too thin, then it may be too delicate to reliably handle and process as described herein. If the first dielectric plate 32 is too thick, then it may undesirably increase thermal resistance between the electronic device 12 and the coolant 16 .
[0018] The device package 14 may also include a lead frame 36 electrically coupled to the electronic device 12 and extending beyond the first plate perimeter 34 . The lead frame may be formed of copper or a copper alloy, and may be fabricated by folding, coining, and/or shearing as will be known by those in the art. The lead frame 36 may advantageously formed of a metal that has a CTE that closely matches the material selected for the first dielectric plate 32 . Closely matched CTE's are desirable for the same reasons of improved reliability given above. The lead frame 36 illustrated has several leads or fingers coupled together by a joining section for the purpose of simplifying the assembly of the lead frame 36 to the first dielectric plate 32 . It will be recognized by those in the art that all or part of the joining section may be cut off along the dashed line 42 after the device package 14 is assembled so that individual connections to the several legs are not electrical shorted together.
[0019] The device package 14 may also include a second dielectric plate 38 attached to the second planar side 28 . The second dielectric plate 38 generally defines a second plate perimeter 40 that extends beyond at least a corresponding portion of the device perimeter 30 that corresponds to at least a portion of where the first plate perimeter 34 extends beyond the device perimeter 30 . The attachment of the first dielectric plate 32 and the second dielectric plate 38 to the electronic device 12 may be by way of soldering, sintering, or conductive adhesive as will be recognized by those in the art. FIG. 2B does not show the second dielectric plate 38 overlaying the lead frame 36 only for the purpose of simplifying the illustration. It is recognized that the second dielectric plate 38 may be extended to overlay all or part of the lead frame 36 for the purpose of making an electrical connection between the lead frame 36 and the second planer side 28 of the electronic device 12 . Preferably, the second dielectric plate has the same thickness as the first dielectric plate 32 so that stresses on the electronic device 12 are substantially balanced after the device package 14 is assembled.
[0020] Further details regarding the assembling of the electronic device 12 , the first dielectric plate 32 , the second dielectric plate 38 , and the lead frame 36 may be found in U.S. Pat. No. 6,812,553 issued to Gerbsch et al. on Nov. 2, 2004, and U.S. Pat. No. 7,095,098 issued to Gerbsch et al. on Aug. 22, 2006. The entire contents of both patents are hereby incorporated herein by reference. It is noted that the electronic package described in these patents would not be suitable for immersion cooling because of the gap between the dielectric plates that would allow coolant to contact the electronic device therebetween. The benefit of having the first plate perimeter 34 and the second plate perimeter 40 extend correspondingly beyond the device perimeter 30 will become apparent as sealing of the device package 14 to protect the electronic device 12 from the coolant 16 is described below.
[0021] To avoid the problem of coolant contacting the electronic device 12 , the device package 14 includes a first metallic seal 44 formed between a portion of the first plate perimeter 34 that extends beyond the device perimeter 30 , and a corresponding portion of the second plate perimeter 40 . In general, the first metallic seal 44 isolates the electronic device 12 from the coolant 16 . Preferably, the first metallic seal 44 formed by one of silver sintering or soldering. A sintered seal is formed using heat and pressure and is thought to be stronger and more reliable than a soldered seal. However, a soldered seal joint can be formed without the added complexity of applying pressure to the device package 14 , but a soldered seal may be less reliable because of intermetallic alloys between the solder and base metal on the dielectric plates, for example, see metalized region 46 and metallization layer 54 described below. Sintering may also be preferable because it would not be affected if the device package was subjected to a subsequent soldering operation, for example when the device package is installed into the housing 18 . As such, the first dielectric plate 32 , the second dielectric plate 38 , and the first metallic seal 44 cooperate to form the device package 14 .
[0022] FIG. 2A illustrates a non-limiting example of a metalized region 46 that defines the location of the first metallic seal 44 . A suitable width of the metalized region 46 is 3 mm. The metalized region 46 may include a layer of thick-film ink printed and fired onto the first dielectric plate 32 . Alternatively the metalized region 46 may be built upon a foundation of thin film metal deposited onto the first dielectric plate 32 . If the electronic device 12 is thin enough, for example less than 0.12 mm, then the metalized region 46 may be made sufficiently thick on the first dielectric plate 32 , and a corresponding metalized region (not shown) may be established on the second dielectric plate 38 so that the first metallic seal 44 can be formed. In one embodiment, the metalized region 46 may have a plating thickness about equal to or slightly greater than (e.g. 1 mil) half of a device thickness of the device so that when the metalized regions are joined, the electronic device 12 is closely coupled to the first dielectric plate 32 and the second dielectric plate 38 .
[0023] FIG. 3 illustrates a non-limiting example of a perimeter frame 48 . If the electronic device 12 is thicker than about 0.12 mm, then it may be preferable to use the perimeter frame 48 sized and shaped to overlay the metalized region 46 in order to provide additional material thickness that properly fills and seals a gap 60 ( FIG. 4 ) between the first dielectric plate 32 and the second dielectric plate 38 . In one embodiment, the lead frame portion of the perimeter frame 48 may have a different or variable thickness relative to the portion of the perimeter frame 48 overlying the metalized region 46 so that the thickness of the lead frame portion is appropriate for a desired stiffness of the leads, and the portion overlying the metalized region is appropriate to allow for single layer printing to dispense material onto the metalized region 46 for forming the first metallic seal 44 .
[0024] It is recognized that other types of seals between the first dielectric plate 32 and the second dielectric plate 38 are possible, for example dipping the assembly of the first dielectric plate 32 , second dielectric plate 38 and electronic device 12 into a polymeric coating material, or spraying a similar material. However, it is believed that such non-metallic seals would not provide sufficiently reliable seals in view of the typical negative forty (−40) to positive one hundred twenty five (+150) degree Celsius (° C.) operating temperatures for automotive applications. Furthermore, any additional coating over the exposed surfaces of the first dielectric plate 32 and/or the second dielectric plate 38 would likely reduce heat transfer from dielectric plates to the coolant 16 . Applying a polymeric or epoxy material into the gap 60 between the first dielectric plate 32 and the second dielectric plate 38 is also considered undesirable as it is considered to be less reliable than a metallic type seal.
[0025] Referring again to FIG. 1 , the housing 18 generally defines an opening 50 through which the device package 14 may be inserted and secured in place by forming a second metallic seal 52 between the device package 14 and the opening 50 . The second metallic seal 52 is preferably formed by soldering, as opposed to using only a polymeric material. Soldering is preferred in order to reliably prevent the coolant 16 from passing out of the cavity 24 through the opening 50 , as described above with regard to the first metallic seal 44 . The second metallic seal 52 may include a metallization layer 54 ( FIG. 2B , FIG. 4 ) applied to the first dielectric plate 32 and the second dielectric plate 38 . Like the metalized region 46 , the metallization layer 54 may be a direct bond metal layer such as copper directly bonded to the dielectric plate, or may be another form of patterned metal suitable for cooperating with other materials to form the second metallic seal 52 .
[0026] In one embodiment, the metallization layer 54 may extend around the edges of the first dielectric plate 32 and the second dielectric plate 38 so that the second metallic seal 52 goes all the way around the device package 14 , including extending over the first metallic seal 44 .
[0027] With this arrangement, an electronic device 12 may be located within the cavity 24 in order to make intimate contact with the coolant 16 , and the lead frame 36 is used to electrically coupled to the electronic device and extend outside the cavity 24 through the opening 50 in the housing 18 so that an electrical connection to the lead frame 36 can be readily made. Preferably, the device package 14 is oriented to protrude into the coolant such that the plane of the device package 14 or electronic device 12 is substantially parallel to a flow direction 56 of the coolant 16 from the inlet 20 to the outlet 22 . By making the device package 14 substantially parallel to the flow direction 56 , it is believed that the electronic device 12 is cooled more uniformly than other orientations.
[0028] Continuing to refer to FIG. 1 , it may be preferable to form most of the housing 18 of one material, a polymeric compound for example, but form the portion of the housing 18 that includes the opening 50 of a solderable material so the second metallic seal 52 is readily formed. As such, the assembly 10 or housing 18 may include a carrier plate 58 that defines the opening 50 , and is coupled to the housing 18 in a manner effective to form a fluidic seal 62 between the carrier plate 58 and the housing 18 . The fluidic seal 62 may include a sealant such as silicone adhesive, or an ethylene propylene diene monomer (EPDM) gasket. The carrier plate 58 may be secured to the housing 18 by the sealant, or may be secured using fasteners such as screws. Alternatively, if the materials used to form the carrier plate 58 and the housing 18 are compatible, the carrier plate 58 may be attached to the housing 18 using the known process of friction stir welding.
[0029] FIG. 5 illustrates a non-limiting example of a carrier plate 58 having several of the device package 14 installed and preferably secured to the carrier plate 58 by the second metallic seal 52 (not specifically shown). The carrier plate 58 is preferably formed of a material having a CTE similar to that of the device package 14 for the same reasons give above with regard to the first metallic seal 44 . By way of example and not limitation, the carrier plate 58 may be formed of nickel iron alloy # 42 .
[0030] FIG. 5 further illustrates an optional feature of a sealant 72 applied to encapsulate the lead frame 36 proximate to where the lead frame 36 protrudes from the device package and proximate to the opening 50 . The sealant 72 may be a room temperature vulcanization (RTV) type material, or it may be a curing epoxy type. Applying the sealing 72 is believed to help protect the lead frame 36 for vibration induced failures, and provide another barrier against coolant leaking.
[0031] FIG. 4 illustrates additional non-limiting features that may be part of the device package 14 . The device package 14 may include complementary metallization 64 on each side of both the first dielectric plate 32 and the second dielectric plate 38 . As used herein, complementary metallization means that a metallization pattern on one side of a particular dielectric plate is generally mirrored on the other side of that dielectric plate. While not subscribing to any particular theory, it is believe that by providing the complementary metallization 64 , the risk or tendency of the particular dielectric plate to warp as temperature varies is reduced. By reducing the tendency to warp, the complementary metallization 64 helps to balance stress in the device package 14 and thereby improve reliability and manufacturability. The same theory may be applied to the attachment of the first dielectric plate 32 and the second dielectric plate 38 to the electronic device 12 . In this case, the first planar side 26 ( FIG. 1 ) defines a first attachment region for the electronic device 12 , and the second planar side 28 defines a second attachment region such that when the electronic device 12 is attached to the first dielectric plate 32 and the second dielectric plate 38 , stress on the electronic device 12 is substantially balanced, meaning that stresses that may try to warp the electronic device 12 are minimized.
[0032] FIG. 6 illustrates additional non-limiting features of the device package 14 . The first dielectric plate 32 and/or the second dielectric plate 38 may include features on an exterior surface 66 of the device package 14 that increase the surface area of the device package 14 , for example micro-channels 68 formed on the dielectric plates. Increasing the surface area of the device package 14 is generally believed to improve heat transfer from the device package 14 to the coolant 16 . The micro-channels 68 may be formed by extrusion of the material used to form the dielectric plate, for example aluminum nitride. the aluminum nitride may be dry pressed and fired using known manufacturing methods of forming various “3D” shapes of ceramic.
[0033] FIG. 7 illustrates additional non-limiting features of the device package 14 . The first dielectric plate 32 and/or the second dielectric plate 38 may include a metal heat sink 70 attached to each dielectric plate. The metal may be copper or other suitable material, and the metal heat sink may be attached by soldering, sintering, gluing, or other methods known to those in the art.
[0034] Accordingly, a liquid cooled power electronics assembly 10 is provided. The assembly 10 makes use of metallic seals ( 44 , 52 ) to provide robust seals suitable for automotive application that prevent the coolant 16 from leaking out of the housing 18 , and/or contacting the electronic device 12 within the device package 14 . The assembly 10 is particularly advantageous because it minimized the thermal path between the heat generating electronic device 12 and the coolant 16 when compared to other arrangements. Testing has demonstrated that the assembly 10 described herein has a power dissipating rating of 0.11 degrees Celsius per Watt (0.11° C./W), while an in-production assembly market by Delphi Inc. of Troy, Mich. under the moniker Viper has a less desirable rating of 0.15° C./W. While well suited for the automotive industry, the teachings set forth herein are applicable to other industries.
[0035] While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow. | A liquid cooled power electronics assembly configured to use electrically conductive coolant to cool power electronic devices that uses dielectric plates sealed with a metallic seal around the perimeter of the dielectric plates to form a device assembly, and then forms another metallic seal between the device assembly and a housing. The configuration allows for more direct contact between the electronic device and the coolant, while protecting the electronic device from contact with potentially electrically conductive coolant. Material used to form the dielectric plates and the housing are selected to have similar coefficients of thermal expansion (CTE) so that the reliability of the seals is maximized. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application under 35 U.S.C. §120 of U.S. application Ser. No. 10/989,013, entitled “AXIS TRANSLATION INSTALLATION MECHANISM FOR OPTOELECTRONICS MODULES”, filed on Nov. 15, 2004 now U.S. Pat. No. 7,255,495, which is hereby incorporated herein in its entirety.
BACKGROUND ART
Optoelectronic modules include circuitry for converting between signal processing/transmission in an optical mode and signal processing/transmission in an electrical mode. The conversion may be in a single direction, but many modules provide bidirectional conversions to enable data exchanges in both modes. Optoelectronic modules are used in telecommunications central offices and in centralized computing facilities, where there is a significant demand for high bandwidth communications. As compared to metal interconnects, such as copper wiring, optical interconnects offer benefits with regard to both bandwidth and performance (e.g., less skew), while satisfying requirements relating to eye safety, electromagnetic compatibility, reliability, manufacturability, and cost.
It is common to couple an array of optoelectronic modules to a single substrate, such as a printed circuit board. Connectivity of a particular module is provided by coupling a module connector to a substrate connector. Edge-card style connectors are often used, but parallel optical links typically require the use of high-density electrical connectors to accommodate the larger number of electrical signals that must be managed. A single optical link may combine twelve optical channels that are separated into twelve electrical signals within the module. It follows that for each such link, there is a need for twelve electrical paths between the module and the substrate. Thus, the edge-card style connectors are sometimes replaced by connectors having pin-and-socket arrangements. The pins are rigid wire strands of electrically conductive material that are received within sockets having a fixed arrangement that corresponds to that of the pins.
A greater degree of flexibility with regard to the maintenance of the telecommunications central office or the centralized computing facility is available if the optoelectronic modules are replaceable. A difficulty is that the openings for inserting and removing optoelectronic modules through the housing of the host system typically allow the greatest degree of freedom for module movement in the Z axis, i.e., the axis that is parallel to the surface of the substrate on which the substrate connectors are mounted. This is shown in FIGS. 1 and 2 . A printed circuit board 10 having an electrical connector 12 is shown as being within the interior of a housing that includes a bezel, or faceplate 14 . The optoelectronic module 16 enters the housing through an opening within the faceplate, as indicated by the arrow 18 along the Z axis. However, the seating of the module must occur along the Y axis, which is represented by arrowed line 20 . The module connector 22 must properly seat onto the substrate connector 12 , but the direction of movement for seating the module is orthogonal to the greatest degree of freedom of module movement. Either before or after the module connector is seated, an optical fiber 29 is joined to the optoelectronic module to input/output optical signals.
One solution is to mount a substrate connector that has a seating direction perpendicular to the printed circuit board 10 (i.e., along the Z axis). The module connector 22 must be relocated to the rear surface of the optoelectronic module 16 , rather than the bottom surface as shown in FIGS. 1 and 2 . This allows the user to merely push the module rearwardly until the two connectors are seated together. This solution has benefits, but may impose restrictions on signal density. An alternative solution is described in U.S. Pat. No. 6,074,228 to Berg et al. Pressure contacts are preferably used for the connectors of Berg et al., rather than insertion contacts which require significantly more force in order to provide proper seating. The pressure contacts may be J-shaped leads which deflect slightly when press fit to contact pads of another connector. Since the required mating forces are reduced, the insertion force requirements are relaxed. The substrate connector of Berg et al. has a body that includes a guide member, which is elongated along the Z axis. The elongated body of the substrate connector is surface mountable on a printed circuit board. The connector body also includes a camming element that is comprised of ramped regions. When the replaceable module is slid along the elongated body of the connector, a cam follower of the module raises and lowers the end of the module because of contact with the ramped regions of the camming element. While the raising and lowering of the module brings the module connector into contact with the leads of the substrate connector, the pressure contact may not be sufficient for some applications. Specifically, there may be concerns that less than all of the leads of the substrate connector have a low resistance connection to the contact pads of the module connector.
SUMMARY OF THE INVENTION
The seating of an optoelectronic module onto a substrate connector includes guiding the module along an initial path portion that is misaligned from the mating direction of the substrate connector and includes providing a positive pressure drive along an end path portion with sufficient force to secure the optoelectronic module to the substrate connector. For applications in which the substrate and module connectors are electrical connectors that are coupled using a pin-and-socket arrangement, the positive pressure drive is enabled to push the main body of the optoelectronic module with sufficient force to ensure entry of the pins into the sockets.
In a system for controlling the coupling of module connectors of a number of optoelectronic modules to an array of substrate connectors on a substrate, such as a printed circuit board, each optoelectronic module is associated with a device having a slide configured to receive the optoelectronic module so as to enable sliding movement of the module and includes a drive mechanism coupled to the slide to displace the slide toward and away from the substrate. In the sliding movement of the module, the module remains non-coplanar with the substrate connector to which it is to be coupled. However, the drive mechanism then displaces the slide toward and away from the substrate, with the displacement being such that the module connector is aligned to couple with the substrate connector.
The method of controlling coupling of a module connector to a substrate connector may be described as including the step of sliding the optoelectronic module along a plane that is parallel to the substrate surface on which the substrate module is fixed. During this sliding movement, the module connector remains at a distance from the substrate surface such that the two connectors remain in a non-coplanar relationship. The method includes mechanically applying a coupling force to push the optoelectronic module toward the substrate in a controlled alignment to securely couple the module and substrate connectors. In a decoupling operation in accordance with the method, a decoupling force that is the reverse of the coupling force is mechanically applied to unseat the module connector from the substrate connector. The optoelectronic module is then slid along the same plane followed during the initial insertion, but in the reverse direction.
As one possibility, the seating device includes a slide that remains stationary as the optoelectronic module is slid into place. The slide has a slide surface which defines the initial path portion for movement of the module. After the sliding action has been completed, a cam is pivoted to press the slide surface toward the substrate. A cam handle remains exposed to provide access by a user. When the cam handle is rotated in one direction, the connector of the optoelectronic module is seated to the substrate module. Rotation of the cam handle in the opposite direction unseats the connectors.
In another embodiment, the seating device includes a sliding cam. The device has a slide that is perpendicular to the mating direction of the connectors. The positive pressure drive of the device includes an actuator and slots that are aligned with the mating direction. In this embodiment, movement of an actuator in the mating direction controls movement of the slide. For applications in which the substrate is mounted horizontally, the slide structure is moved horizontally to a position that aligns the substrate and module connectors and then is moved vertically to bring the two connectors into contact.
In a rocking slide cam embodiment, the angle of the optoelectronic module varies with approach toward a seated condition of the connectors. For example, a number of actuator pins may be received within a corresponding number of grooves configured to determine the variation in module angle. In this embodiment, an actuator and the optoelectronic module may be in a fixed relationship with travel of the module along the initial path portion. However, the actuator is moved relative to the optoelectronic module during the end path portion, when the force is applied for seating the module connector with the substrate connector.
The seating device also has a mechanical toggle switch embodiment. In this embodiment, linkage may be used to translate motion of an actuator along an axis that is perpendicular to the mating direction into motion of the optoelectronic module in the mating direction.
The positive pressure drive may also be provided by a stroke multiplier mechanism in which motion of an actuator in a direction perpendicular to the mating direction is translated to motion in the mating direction by orientations of at least two slots. For example, a first slot in a fixed rail may have an orientation opposing a second slot in a movable slide. Additionally, vertical slots in the rail may be used to constrain the motion of the slide vertically, so that force applied to the actuator is desirably coupled to the slide.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an optoelectronic module to be seated within the interior of a host system.
FIG. 2 is a side view of the optoelectronic module positioned above the connector to which the module is to be seated.
FIG. 3 is a Z axis view of a force latch mechanism as one embodiment for seating an optoelectronic module in accordance with the invention.
FIGS. 4 , 6 , 8 and 10 are front view of different steps in the operation of the force latch mechanism of FIG. 3 .
FIGS. 5 , 7 , 9 and 11 are rear views of the different steps for operating the force latch mechanism of FIG. 3 .
FIG. 12 is a perspective view of a sliding cam mechanism in accordance with a second embodiment of the invention.
FIG. 13 is a side view of the sliding cam mechanism of FIG. 12 with an optoelectronic module in a raised position.
FIG. 14 is a side view of the sliding cam mechanism of FIG. 12 with the module in its seated position.
FIG. 15 is a rocking slide cam mechanism in accordance with a third embodiment of the invention.
FIGS. 16-19 illustrate different steps in the operation of the rocking sliding cam mechanism of FIG. 15 .
FIG. 20 is a toggle switch mechanism in accordance with a fourth embodiment of the invention.
FIGS. 21 and 22 are side views of steps for operating the toggle switch mechanism of FIG. 20 .
FIG. 23 is a side view of a stroke multiplier mechanism in accordance with a sixth embodiment of the invention.
DETAILED DESCRIPTION
The invention is a means for seating an optoelectronic module, such as the module 16 shown in FIGS. 1 and 2 , to a connector 12 on a substrate 10 , such as a printed circuit board. A user is able to insert and withdraw the module through an opening in the faceplate 14 without withdrawing the substrate from the host system. In the embodiments to be described below, the module moves in the Z axis direction 18 before force is applied in the Y axis direction 20 , but the directions are not necessarily horizontal and vertical. While the seated connectors 12 and 22 will be described as being electrical connectors, in some applications the invention may be used to properly seat optical connectors. In such applications, the optical fiber 29 is replaced with electrical input/output members, since the module 16 is one in which conversions between an optical mode and an electrical mode are performed. As will be recognized by a person skilled in the art, the ability to connect and disconnect the fiber 29 may be replaced with a “pigtailed” module in which the fiber is fixed with respect to the module.
A first embodiment of the seating device is shown in FIG. 3 . This embodiment takes the form of a force latch mechanism 24 that is able to simultaneously apply force in two perpendicular directions so as to install or remove the optoelectronic module 16 . The mechanism includes a slide member 26 , a rail 28 , and a slide pin 30 . A recess 32 within the module 16 is aligned to receive the slide 26 . While not shown in FIG. 3 , the module rests on the upper surface of the slide 26 .
The module connector 22 is shown as being positioned above the substrate connector 12 . In operation, the module 16 slides along the top surface of the slide 26 with the two connectors remaining misaligned relative to the distance from the substrate on which the connector 12 resides. In the embodiment of FIG. 3 , the substrate connector 12 includes an array of pins 34 that project upwardly for reception within a corresponding array of sockets within the module connector 22 . Alternatively, the socket-and-pin arrangement may be reversed.
FIGS. 4 and 5 respectively show front and rear views of the force latch mechanism 24 , but without a module. For purposes of illustration, the slide 26 has been removed from the mechanism 24 in FIG. 5 . A cam 36 is attached to the rail 28 at a sliding cam pin 38 . The cam includes a cam handle 40 that is accessible to a user during a seating or unseating operation.
In a seating operation, the module is slid along the surface of the slide 26 to the position shown in FIG. 3 . After the module is fully inserted, the user pushes the cam handle 40 in the direction indicated by arrows 42 and 44 . The initial movement of the module may be considered to be along the Z axis, but the orientation of movement is not critical to the invention.
The force applied to the cam handle 40 causes the cam pin 38 to slide along the first path portion of a slot 46 within the rail 28 . When the cam pin reaches the end of the first path portion, the cam handle 40 may be pivoted upwardly such that the cam pin follows an arcuate second path portion of the slot 46 .
The front and rear views of FIGS. 6 and 7 , respectively, show the condition of the force latch mechanism 24 when the cam pin 38 has reached the end of the first path portion of the slot 46 . Because a fixed rail pin 48 engages a slot 50 within the cam 36 , the movement of the cam pin along the first path portion induces some pivoting, as indicated by arrow 52 . That is, the combination of the cam pin within the rail slot and the rail pin within the cam slot determines movement of the cam as the user applies pressure to the cam handle 40 of FIG. 4 . The cam pin reaches the end of the first path portion simultaneously with the rail pin reaching the end of the cam slot. At this point, the cam contacts the slide pin 30 that is entrapped within a vertical opening 56 .
FIGS. 8 and 9 illustrate the next step in the seating operation. Here, the cam is rotated as the user applies pressure to the cam handle (not shown). The cam rotates about the rail pin 48 . This forces the slide pin 30 to move downwardly within the vertical opening 56 , thereby displacing the slide 26 downwardly. Since the module is mounted to the slide, the module also moves downwardly.
In FIGS. 10 and 11 , the cam handle has been fully rotated. Consequently, the slide and module have been forced downwardly to achieve mating with the substrate connector 12 of FIG. 3 . Sufficient force is provided to ensure that the pin-and-socket arrangement of the two connectors 12 and 22 provides low resistance coupling of the pins 34 with the optoelectronic module 16 .
The steps for removing the optoelectronic module 16 of FIG. 3 are the reverse of those described with reference to FIGS. 4-11 . The cam handle 40 is rotated in a counterclockwise direction and is pulled rearwardly to the position shown in FIG. 4 . This allows the module to be easily removed from the slide 26 . While the manipulation of the cam handle has been described as being manual, the force latch mechanism 24 may be adapted to hydraulic, pneumatic or electromechanical systems.
FIG. 12 illustrates a second embodiment of the invention. In this embodiment, the seating device is a sliding cam mechanism 58 . The mechanism couples perpendicular motion by use of a slide 60 having diagonal slots 62 and 64 . A rail system is composed of the slide 60 , an actuator 66 , and a rail 68 . In this embodiment, the optoelectronic module 16 travels in the Z axis and engages the slide by means of a groove. The slide may be considered to be a sliding cam. The rail may be connected to the substrate by screws or other fasteners which pass through a pair of openings 70 and 72 within a bracket 74 .
FIG. 13 shows the optoelectronic module 16 in a raised position, while FIG. 14 shows the module in a fully seated position. Once the module is inserted, the actuator 66 accomplishes the Y axis (vertical) motion of the module by coupling the paths of various slots with the module. As best seen in FIG. 13 , the actuator extends to a sliding member 76 that lies within a rail slot 78 of the rail 68 . The sliding member 76 has projections which extend into the diagonal slots 62 and 64 on the slide 60 . Since the slots extend diagonally upward, horizontal motion of the sliding member 76 and its projections is translated into vertical motion of the slide 60 and the module that is coupled to the slide. A pair of pins 80 and 82 extending from the slide project into vertical slots 84 and 86 within the rail 68 . As represented by arrow 88 , motion of the slide 60 is confined to the vertical by the use of the pins 80 and 82 within the vertical slots 84 and 86 . The vertical slide-rail constraint can be achieved in other manners, such as by the use of dovetail joints or folded edges that capture the slide.
The operational steps of a third embodiment are illustrated in FIGS. 15-19 . Here, the seating device is a rocking slide cam mechanism 98 . In this embodiment, the number of components is reduced, but the complexity of individual components is increased. A rail 90 receives the optoelectronic module 16 . The slots 92 and 94 within the rail are configured to cause the module to rock as pressure is applied to an actuator 96 . That is, rocking motion occurs as opposed to the straight vertical descent of the embodiment of FIGS. 12-14 . The illustrated embodiment operates well with the MEG array connector known in the art.
In FIG. 15 , the optoelectronic module is inserted into the rocking slide cam mechanism 98 . A user can apply pressure directly to the module or to the actuator 96 . A rigid protrusion 100 extends beyond the module and initially rides within a slot groove 102 .
The arrow 104 in FIG. 15 represents the movement of the module 16 relative to the actuator 96 and the rail system 90 . After the module has been properly seated, the actuator is pressed inwardly, as represented by arrow 106 in FIG. 16 . Within each slot 92 and 94 resides an actuator pin 108 and 110 . Immediately prior to the application of force to the actuator 96 , the actuator pins are at the ends of the slots, as shown in FIG. 16 . As the module is pushed rearwardly, the two actuator pins 108 and 110 follow their respective grooves, but the grooves have different geometries such that the pins follow different paths.
Referring now to FIG. 17 , when the protrusion 100 at the end of the module 16 clears the slot groove 102 , the rear of the module is no longer supported by the rail system 90 . However, the two actuator pins 108 and 110 control the position of the module by means of their engagement with the respective slots 92 and 94 . The slots in the rail system are designed such that the module exhibits a slight tilt, which is intended to accommodate the high mating force required for high density electrical connectors.
The rearward movement of the module 16 causes the protrusion 100 to abut a hard stop 112 . The contact of the protrusion with the hard stop prevents any further movement of the module along the Z axis (arrow 106 ). In this embodiment, the actuator is able to release from its neutral position, so as to be movable relative to the module. As the user continues to push the actuator 96 , the actuator moves relative to the module, as represented by arrow 114 in FIG. 18 . Movement of the module tracks the geometries of the slots 92 and 94 . The module is forced downwardly to mate with the electrical connector (not shown). In FIG. 19 , the actuator 96 has reached its final position. In this position, the module 16 is locked into its seated position with no tilting. An unseating operation follows the reverse of the seating operation.
The geometry of the slots 92 and 94 can be designed to accommodate any type of connector. Thus, the principle may be modified for any particular application.
FIG. 20 illustrates a toggle switch mechanism 116 in accordance with another embodiment of the invention. The mechanism includes an actuator 118 , a rail 120 , and a slide 122 . The cooperation of components converts the Z axis motion of the actuator 118 into Y axis translation of the module 16 by means of links 124 and 126 . Each link has a first end that is pivotally connected to the actuator, such that the first ends move linearly with the actuator, but are able to rotate. The opposite end of each link is coupled to a vertical slot 128 and 130 within the rail. A bracket 132 may be used to mount the mechanism to a substrate, such as a printed circuit board.
As best seen in FIG. 21 , the rail 120 includes a second pair of vertical slots 134 and 136 . Engaging each slot is a projection 138 and 140 that is fixed to the slide 122 that supports the module 16 . The engagement of the projections with the vertical slots limits the movement of the slide 122 to vertical movement. The mechanism is shown in the raised position in FIG. 21 . In this position, the projections 138 and 140 are at the upper extents of the slots 134 and 136 . Also, the links 124 and 126 are at only a slight decline.
The slide 122 has a pair of diagonal grooves 142 and 144 . The movement of the actuator 118 is coupled to the slide 122 by means of the grooves. For example, the pivoting ends of the links 124 and 126 may be secured by pivot pins having ends that extend into the diagonal grooves. Thus, as the actuator is pushed inwardly, the links will pivot at their upper ends and will ride along the respective slots 128 and 130 at the their lower ends. Simultaneously, the pivot pins through the upper ends of the links will travel along the diagonal grooves 142 and 144 to apply downward pressure on the slide 122 . This causes the projections 138 and 140 from the slide to travel downwardly along the second pair of vertical slots 134 and 136 within the rail 120 . Eventually, the mechanism will reach its lowered position shown in FIG. 22 , with the connector of the module 16 properly seated to the substrate connector (not shown).
Yet another embodiment is shown in FIG. 23 . The stroke multiplier mechanism 146 includes an actuator 148 , a slide 150 , and a rail 152 . The optoelectronic module 16 is shown as resting in position on the slide. In this figure, the coupler 154 for receiving an input/output optical fiber is included. A pair of opposing diagonal slots 156 and 158 multiply the motion of the input actuator 148 . The first of the diagonal slots 156 is in the fixed rail 152 , while the second slot 158 is in the movable slide 150 . Vertical slots 160 and 162 constrain the motion of the slide vertically. The vertical slots may be either in the rail or the slide. After the module has been engaged to the slide, it is also restricted to vertical movement.
By modifying the angle of the opposing diagonal slots 156 and 158 , it is possible to adjust the stroke multiplication to the degree required for a particular connector. The sliding cam mechanism 58 of FIG. 12 may be considered to be a specific embodiment of a stroke multiplier, if one of the “opposing slots” is identified as the horizontal rail slot 78 .
While a number of mechanisms have been described and illustrated for converting the direction of motion orthogonally so as to seat an optoelectronic module, the invention extends beyond the illustrated embodiments. Moreover, the conversion need not be directly orthogonal, as can be seen by the rocking slide cam mechanism of FIGS. 15-19 , which takes advantage of module tilting to provide the force necessary to properly mate the module connector to the substrate connector. | An optoelectronic module is seated onto a substrate connector by guiding the module along an initial path portion that is misaligned with respect to the mating direction defined by the substrate connector and further includes providing a positive pressure drive along an end path portion with sufficient force to secure the optoelectronic module to the substrate connector. Where the mating is via a pin-and-socket arrangement, the positive pressure drive requires sufficient force to push the main body of the module to ensure entry of the pins into the sockets. Typically, there is a conversion from force applied in one direction to module motion in the orthogonal direction. However, a rocking cam embodiment is also described. | 6 |
RELATED APPLICATIONS
[0001] This application is a continuation in part to application 13/927.252 filed Jun. 26, 2013 which in turn claims priority to U.S. patent application Ser. No. 61/666, 283 filed Jun. 29, 2012, all incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] a. Field of Invention
[0003] This invention pertains to a lamp assembly formed of base an upright leg and cantilevered arm terminating at the free end with a light source. The leg and the arm include compression springs adapted to balance the arm and the light source so that the light source can be moved to any position and stay at the position when released without tipping in any direction. Alternatively, the leg is omitted and the arm mounted directly on a base.
[0004] b. Description of the Prior Art
[0005] Cantilevered lamp assemblies generally included an articulated arm with a light source at the free end and a mounting element used to mount the lamp to a desk, a wall or a stanchion extending to the floor or other flat service. These types of assemblies are used in residential, commercial or industrial settings, including, schools and universities, medical and dental offices, etc.
[0006] Typically, the articulated arm for these lamp assemblies consists of two or more sections joined by complex hinges and other similar interconnecting components. The lamp assemblies are arranged and constructed to allow a user to move the light source in three different directions to direct light from a light source at a particular zone of a surface or work area. The combined weight of the arm sections, the light source and other elements impose considerable forces and twisting torques on the various interconnecting components of the system. It is difficult to make a cantilevered lamp that can resist these forces so that the light source can be moved to virtually any arbitrary position and left there without the light source tipping in any direction.
[0007] In order to resolve this problem, lamps have been devices with various combinations of strain and force relieving means including various cables, strings, pulleys, springs, and arms arranged in a parallelogram etc. Of course, all these relieving means added more parts and complexity to the lamp resulting in increased costs and assembling difficulties. Moreover, external springs and other elements are undesirable since they are exposed to the elements, dust and corrosion and are esthetically unpleasing.
[0008] The present invention provides a lamp assembly in which the above described problems are eliminated, or at least substantially reduced.
SUMMARY OF THE INVENTION
[0009] A lamp constructed in accordance with this invention includes an upright member having a lower end and an upper end defining an upright member longitudinal axis; an arm having a first arm end and a second arm end; a light source attached to said second arm; a first pivot hingedly supporting said lower end; a second pivot hingedly supporting said first arm end at said upper end; said upright member including a support element preventing said arm and upright member from moving once said upright member and said arm have been pivoted to position said light source at a desired location, said support element including a rod having a first and a second rod end and being pivotably supported on a stationary member at said first end, and being pivotably connected to said upright member at said second end, a fixed block, and a first spring coupled between said second rod end and said block, said support element being configured to cause said first spring to compress against said block thereby generating a support force for said arm and said upright member.
[0010] In one embodiment, the upright member includes a sleeve extending between said upper and lower ends, said block being attached to said sleeve, and a first slider attached to said second rod end and reciprocated within said sleeve as said upright member is pivoted, said first spring being compressed between said slider and said block. Preferably, the upright member further includes a second slider slidably disposed in said sleeve near said upper end and connected to said first slider, said first and second slider being moved simultaneously. A second spring is disposed between said second slider and said block, said second spring providing supporting force,
[0011] In one embodiment, the lamp also includes a base, said first pivot being attached to said base. Preferably, the first pivot is adapted to pivot said upright member about a vertical axis and a horizontal axis.
[0012] In one embodiment, the arm includes an arm block and an arm spring, said spring being configured to provide further support forces depending on the position of said upright member.
[0013] In one embodiment, the lamp also includes an arm slider, said arm spring being selectively compressed between said arm slider and arm block an interconnecting member transmitting the movement of said first slider to said arm slider. The second pivot includes a hinge interconnecting said upper and said first arm ends and a cam linkage coupled to said first slider and said arm slider.
[0014] In one embodiment, the upright member includes a second slider slidably disposed in said sleeve near said upper end, said second slider being connected to said first slider and said arm slider, said first slider, second slider and said arm slider being moved simultaneously, and a second spring disposed between said second slider and said block.
[0015] In one embodiment, the leg is mounted in a socket incorporated into a horizontal surface. In another embodiment, a wall mount is provided with its own socket receiving the leg.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows an orthogonal view of the lamp constructed in accordance with this invention;
[0017] FIG. 1A shows an orthogonal enlarged view of the lamp head;
[0018] FIG. 1B shows an orthogonal enlarged exploded view of the lamp head;
[0019] FIG. 2 shows an orthogonal view of the lamp without sleeves;
[0020] FIG. 3 shows left view of the lamp of FIG. 1 ;
[0021] FIG. 3A shows an enlarged view of the elbow as seen from the left;
[0022] FIG. 4 shows a right view of the lamp of FIG. 1 ;
[0023] FIG. 4A shows an enlarged view of the elbow as seen from the right;
[0024] FIG. 5 shows an orthogonal view of the lamp being removed from its base; and
[0025] FIG. 5A shows an enlarged view of the lamp and its base;
[0026] FIG. 6 shows an orthogonal view of another embodiment of the lamp with an arm;
[0027] FIG. 7A shows an orthogonal view of the lamp support for wall mounting;
[0028] FIG. 7B shows two parts of the lamp support separated;
[0029] FIG. 8 shows an orthogonal view of the lamp of FIG. 1 on the lamp support of FIGS. 7A , 7 B; and
[0030] FIG. 9 shows an orthogonal view of the embodiment of FIG. 6 mounted on the lamp support of FIGS. 7A , 7 B.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] Lamp 10 constructed in accordance with this invention includes a leg 12 attached to a base 14 by a hinge or pivot 15 and an arm 16 having a lamp head 18 at one end and attached to the leg 12 by a hinge or pivot 20 .
[0032] The leg 12 includes a sleeve 120 preferably having a rectangular cross section with various internal elements of the lamp(described in detail below and in FIG. 2 ) being disposed in this sleeve. Similarly arm 16 includes a sleeve 160 . A multiconductor wire (not shown) is threaded through the sleeves and extends from the base to the lamp head 18 to provide electricity.
[0033] As shown in FIG. 2 , leg 12 further includes, starting from the bottom, a first slider 122 , two compression springs 124 , a bearing block 126 , two more compression springs 128 , 130 and a second slider 132 . The two sliders 122 , 132 are connected by a pair of parallel rods extending through the bearing block 127 so that the two sliders 122 , 132 always move together longitudinally within sleeve 120 (The springs 124 , 126 , 128 , 130 are wrapped around these rods so that they are not visible in FIG. 2 ). The block 126 is fixed in the sleeve and has holes for the rods interconnecting sliders 122 , 132 .
[0034] Arm 16 has a somewhat similar structure to leg 12 and it includes a slider 162 , two parallel compression springs 164 , 166 ,a fixed bearing block 168 and two rods 170 172 slidably passing through block 168 . In this case, one end of the rods 170 , 172 is secured to the slider 162 and the other end to the end block 174 .
[0035] Wherever two parallel compression springs are shown, it is possible to use a single spring, however two parallel springs provide a smoother motion and insure that sliders attached thereto do not jam.
[0036] Referring now to FIGS. 3 , 3 A, 4 , 4 A, the hinge 20 is provided between the leg 12 and arm 16 to allow the arm 16 to be rotated with respect to the leg 12 as desired. The hinge includes a pin 200 with a cam linkage 202 and a first rod 204 connected between the top end 132 A of slider 130 and the cam linkage 202 . Another rod 206 extends between the cam linkage 202 and an end 162 A of slider 162 . The cam linkage 202 is generally triangular and is pivotably mounted on pin 200 . The rods 204 and 206 are also pivotably connected to the cam linkage 202 and the respective sliders 132 , 162 . As mentioned above, the arm 16 and leg 12 can be be pivoted with respect to each other through hinge 20 .
[0037] Referring to FIGS. 5 and 5A , hinge 15 includes a hinging mechanism 150 arranged to hingedly a couple disc-shaped element 152 with leg 12 . In addition, a rod 154 is hingedly connected at one end with base 152 and at the other end with the lower end 122 A of slider 122 .
[0038] Base 14 is provided with a round hole 142 having a bottom plate 144 . The round hole 142 is sized and shaped to element 152 . The element 152 (and therefore the rest of the lamp) is rotatably attached to the base 14 by screw 146 . The element 152 has an extension (not shown) that engages the plate 144 such that the rotational movement of the element 152 is limited to a predetermined angle, about a vertical axis (not shown) passing through hole 142 such as 90 degrees.
[0039] Referring to FIGS. 1 , 1 A and 1 B, head 18 includes a generally square housing 180 holding a light source, such as an LED panel (not shown). The lighting panel is powered from a wire snaking through from the base 14 , through leg 12 and arm 16 and controlled by a switch 194 . In one embodiment, switch 194 is a multi-position proximity switch that senses when a person's hand is hovers over the switch 194 and operates the LED panel by setting off or turning on at one or more intensities.
[0040] The head 18 is attached to arm 16 by a hinge 17 including a sleeve 182 extending into the end 174 of arm 16 . A corner piece 184 is formed with two pins 186 , 188 . A second sleeve 190 is captured within a hole 190 in housing 180 as shown. The pins 186 , 188 are inserted into, and are captured by sleeves 182 , 190 respectively.
[0041] As discussed above, the hinges 15 , 17 , 20 provide several degrees of freedom of rotation for head 18 . More particularly, leg 12 can be rotated with respect to base 14 about a horizontal axis X 1 -X 1 and a vertical axis Z-Z. Arm 16 can rotate about a horizontal axis X 2 -X 2 with respect to leg 12 . Head 18 can rotate about a horizontal axis X- 3 , X- 3 and another axis Y-Y with respect to arm 16 .
[0042] Of course without any further restraints, once the head 18 is positioned to any arbitrary location with respect to the base 14 and is then released, the head 18 would either flop down or the hinges 15 , 20 , 17 would have to be so tight as to render essentially unusable. Thus the head 18 , as well as the arm 16 and leg 12 are provided support by the members within the sleeves 120 , 160 as follows. Pivoting the leg 12 backward, away from the base 14 , causes the sliders 122 , 132 to slide up. Since block 127 is fixed in position, this motion of the sliders 122 , 132 causes springs 124 , 126 to compress. In addition, when slider 132 moves upward, the rod 204 causes the cam linkage 202 to rotate counterclockwise (as viewed in FIG. 2 or 3 A) thereby pushing the slider 162 to the right via rod 206 , and thereby compressing springs 164 , 166 against block 168 and causing the arm 14 to rotate counterclockwise.
[0043] Moving the leg 12 for causes reverses the action just described. When the leg 12 is pivoted beyond 90 degrees with respect to the base, springs 128 , 130 are compressed against block 127 .
[0044] When the leg 12 , arm 16 or lamp 18 are released, the force of the springs that are compressed retains the leg 12 and arm 16 in their last respective positions. In this manner, the need for cumbersome and expensive arrangements with parallelograms, or other external means such as springs, cables, pulleys, etc., as used in previous mechanisms is eliminated.
[0045] The arrangement of springs blocks and sliders disclosed herein may be used in other types of devices as well, not just lamps.
[0046] FIG. 6 shows another embodiment of the invention. In this embodiment, a lamp 210 includes a base 214 , an arm 216 and a light source 218 . The base 214 is identical to the base 14 in FIG. 1 , the light source 218 is identical to light source 18 and is mounted to arm 216 by a hinge 217 that is identical to hinge 17 . The arm 216 is connected to the base 214 by a hinge 215 that is identical to hinge 215 . Arm 216 is formed of a hollow sleeve 260 which houses includes slider 162 , the two parallel compression springs 164 , 166 , fixed bearing block 168 and the two rods 170 172 slidably passing through block 168 . One end of each of the rods 170 , 172 is secured to the slider 162 and the other end to the end block 174 forming hinge 217 .
[0047] However end 162 A of slider 162 is now connected one end of rod 154 (see ( FIG. 6 ). The sleeve 260 is connected to hinge 150 . The hinge 150 and the rod 154 are connected to cylindrical element 152 which fits in a matching hole in base 214 . The element 152 can rotate about a vertical axis with respect to the base 214 thereby rotating light source 218 . The arm 216 can pivot by about 85-110 degrees with respect to a horizontal axis defined by hinge 150 .
[0048] In another embodiment of the invention, the lamps described above can be provided in a wall-mounted version. For this embodiment, a wall mount 300 is provided instead of base 14 or 214 . As shown in FIGS. 7A and 7B wall mount 300 includes an L-shaped support 302 and a sleeve 304 . The support 302 includes a horizontal portion 310 formed with a hole 342 similar to hole 142 in FIG. 5A . Hole 342 is sized and shaped to receive cylindrical element 152 . The support 302 further includes a vertical wall 310 that is generally flat and is made with several mounting holes 312 for securing the wall support to a vertical surface. The wall 310 is formed with two side wings 314 that are offset from the rest of the wall 310 . An L-shaped bar 316 reinforces the support 302 and may be hollow to accommodate electrical wiring for the lamp.
[0049] Sleeve 304 is sized and shaped to fit over the wall 310 and cover it, as shown in FIG. 7B .
[0050] FIG. 8 shows a wall mounted lamp similar to the one shown in FIGS. 1-5 but being mounted on support 300 .
[0051] FIG. 9 shows a wall mounted lamp similar to the one shown in FIG. 6 but being mounted on support 300 .
[0052] Numerous modifications may be made to this invention without departing from its scope as defined in the appended claims. | A lamp suitable for desk tops and the like includes a leg or upright resting on a base or other stationary element. An arm is secured to the leg and has a light source at its end. The arm and upright can be pivoted about various axes to allow the light source to be positioned arbitrarily to various positions. A support mechanism is provided inside the upright and the arm. The mechanism includes coil springs that are selectively compressed as the arm and upright are moved to generate supporting forces. The arm and upright does maintain their position and do not fall over after the light source has been positioned to the desired location. In another embodiment, the leg is omitted. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to organopolysiloxane compositions which are hardenable to elastomers at ambient temperature, and, more especially, to such compositions comprising acyloxy radicals bonded to silicon atoms and further including hardening accelerators which comprise hydroxides of the alkali and alkaline earth metals.
The subject compositions, in contrast to the known one-component compositions also comprising acyloxy radicals bonded to silicon atoms (described, in particular, in French Pat. Nos. 1,198,749, 1,220,348 and 2,429,811, U.S. Pat. No. 3,133,891, and published French Application No. 82/13,505, filed on July 30, 1982), are not stable upon storage, but the time required for the cross-linking thereof is much shorter, for example, on the order of a few minutes up to 60 minutes. They must therefore be directly prepared as and when required.
The subject compositions are also capable of being employed in fields of application which require a short cross-linking time regardless of the degree of humidity of the surrounding atmosphere, such as the production of an "in situ" seal in the automobile industry.
2. Description of the Prior Art
Organopolysiloxane compositions comprising acyloxy radicals bonded to silicon atoms, whose cross-linking time is independent of the humidity of the ambient air are known to this art; compare, for example, British Patent Specification No. 1,308,985. More precisely, this patent relates to a process of hardening consisting of adding to the above compositions from 3 to 15% of a sodium silico-aluminate having from 5 to 15% by weight of adsorbed water.
This prior art process makes it possible to manufacture silicone elastomer molded shaped articles by low pressure injection. However, British Patent Specification No. 1,308,985 teaches that it is necessary to attain relatively short hardening times, for example, on the order of 30 minutes, to introduce large amounts of sodium silico-aluminate (15% in the table on page 2); this has the disadvantage of impairing the mechanical properties of the elastomers produced from the compositions. Furthermore, the patent does not mention the means required to obtain cross-linking times less than 30 minutes. Cf. British Patent Specification Nos. 640,067 and 1,181,346.
Consequently, serious need exists in this art for organopolysiloxane compositions comprising acyloxy radicals bonded to silicon atoms, rapidly hardening at ambient temperature, regardless of air humidity, and still providing elastomers having good mechanical properties.
This combination of properties would make it possible, among other things, to employ such compositions for the gluing or sealing of components;
(1) moving on industrial assembly lines, or
(2) for which no storage areas are available to ensure their complete hardening.
SUMMARY OF THE INVENTION
Accordingly, a major object of the present invention is the provision of an improved organopolysiloxane composition comprising acyloxy radicals bonded to silicon atoms, which improved composition has all of the aforenoted required properties.
Briefly, the subject improved organopolysiloxane compositions comprise a polyhydroxylated polysiloxane, a polyacyloxysilane and a hardening accelerator, said hardening accelerator comprising a hydroxide of an alkali metal or of an alkaline earth metal.
DETAILED DESCRIPTION OF THE INVENTION
More particularly according to the present invention, the subject organopolysiloxane compositions which cross-link to elastomers at ambient temperature, advantageously comprise at least:
(A) 100 parts of by weight polymers which are essentially α,ω-di(hydroxy)diorganopolysiloxanes, having a viscosity of 700 to 1,000,000 mPa.s at 25° C., each consisting of a sequence of recurring diorganosiloxy units of the formula R 2 SiO in which the symbols R, which may be identical or different, represent hydrocarbon radicals having from 1 to 8 carbon atoms, optionally substituted by halogen atoms or cyano groups;
(B) 2 to 20 parts by weight of cross-linking agents of the general formula:
R.sub.p Si(OCOR').sub.4-p
in which the symbol R has the meaning given under (A), the symbol R' denotes a hydrocarbon radical free from aliphatic unsaturation, having from 1 to 15 carbon atoms, and the symbol p is zero or one;
(C) 0 to 150 parts by weight of inorganic fillers; and
(D) 0.01 to 7 parts by weight, per 100 parts by weight of (A)+(B)+(C), of hardening accelerators, said accelerators (D) comprising the hydroxides of alkali metals or alkaline earth metals.
The hydroxides of alkali metals or alkaline earth metals may either be anhydrous or hydrated. In a preferred embodiment of the present invention, the hydroxides of lithium, barium, strontium or calcium are used, either in an anhydrous or hydrated form.
The polymers (A) having a viscosity of 700 to 1,000,000 mPa.s at 25° C., preferably 1,000 to 700,000 mPa.s at 25° C., are essentially linear polymers, basically consisting of diorganosiloxy units of the aforesaid formula R 2 SiO, and blocked with a hydroxyl group at each end of their chain; nevertheless, the presence of monoorganosiloxy units of the formula RSiO 1 .5 and/or of siloxy units of the formula SiO 2 is not excluded in a proportion of at most 2% relative to the number of diorganosiloxy units.
The hydrocarbon radicals having from 1 to 8 carbon atoms, optionally substituted by halogen atoms or cyano groups and denoted by the symbols R, are advantageously:
(i) alkyl and haloalkyl radicals having from 1 to 8 carbon atoms, such as the methyl, ethyl, n-propyl, isopropyl, n-butyl, n-pentyl, n-hexyl, 2-ethylhexyl, n-octyl, 3,3,3-trifluoropropyl, 4,4,4-trifluorobutyl or 4,4,4,3,3-pentafluorobutyl radicals,
(ii) cycloalkyl and halocycloalkyl radicals having from 4 to 8 carbon atoms, such as the cyclopentyl, cyclohexyl, methylcyclohexyl, 2,3-difluorocyclobutyl or 3,4-difluoro-5-methylcycloheptyl radicals,
(iii) alkenyl radicals having from 2 to 4 carbon atoms, such as the vinyl, allyl or 2-butenyl radicals, aryl and haloaryl radicals having from 6 to 8 carbon atoms, such as the phenyl, tolyl, xylyl, chlorophenyl, dichlorophenyl or trichlorophenyl radicals,
(iv) cyanoalkyl radicals, the alkyl moieties of which have from 2 to 3 carbon atoms, such as the β-cyanoethyl and γ-cyanopropyl radicals.
Exemplary of units denoted by the formula R 2 SiO, the following are representative:
(CH.sub.3).sub.2 SiO
CH.sub.3 (CH.sub.2 ═CH)SiO
CH.sub.3 (C.sub.6 H.sub.5)SiO
(C.sub.6 H.sub.5).sub.2 SiO
CF.sub.3 CH.sub.2 CH.sub.2 (CH.sub.3)SiO
NC-CH.sub.2 CH.sub.2 (CH.sub.3)SiO
NC-CH(CH.sub.3)CH.sub.2 (CH.sub.2 ═CH)SiO
NC-CH.sub.2 CH.sub.2 CH.sub.2 (C.sub.6 H.sub.5)SiO
It will be appreciated that, in another embodiment of the invention, it is possible to employ as polymers (A) α,ω-di(hydroxy)diorganopolysiloxane copolymers, or a mixture consisting of α,ω-di(hydroxy)diorganopolysiloxane polymers which differ from each other in molecular weight and/or the nature of the groups bonded to the silicon atoms.
Such α,ω-di(hydroxy)diorganopolysiloxane copolymers (A) are readily commercially available; moreover, they can be easily prepared. One of the most widely employed methods of preparation consists, in a first step, of polymerizing diorganocyclopolysiloxanes with the aid of catalytic amounts of alkaline or acid agents and then treating the polymerizates with calculated amounts of water (French Pat. Nos. 1,134,005, 1,198,749 and 1,226,745); this addition of water, which is inversely proportional to the viscosity of the polymers to be prepared, can be wholly or partly replaced with α,ω-di(hydroxy)diorganopolysiloxane oils of a low viscosity, for example, ranging from 5 to 200 mPa.s at 25° C., having a high proportion of hydroxyl radicals, for example, from 3 to 14%.
The cross-linking agents (B) are used in an amount of 2 to 20 parts by weight, preferably of 3 to 15 parts by weight, per 100 parts by weight of the α,ω-di(hydroxy)diorganopolysiloxane polymers (A). They conform to the aforesaid formula:
R.sub.p Si(OCOR').sub.4-p
in which, as heretofore mentioned, the symbol R has the meaning given under (A), the symbol R' denotes a hydrocarbon radical free from aliphatic unsaturation, having from 1 to 15 carbon atoms, and the symbol p is zero or 1.
Precise details have already been given regarding the nature of the radicals denoted by the symbol R. As for the symbol R', this denotes a radical selected from among:
(1) alkyl radicals having from 1 to 15 carbon atoms, such as the methyl, ethyl, n-propyl, n-butyl, n-pentyl, 1-ethylpentyl, n-hexyl, 2-ethylhexyl, n-octyl, neodecyl, n-decyl, n-dodecyl or n-pentadecyl radicals;
(2) cycloalkyl radicals having from 5 to 6 ring carbon atoms, such as the cyclopentyl and cyclohexyl radicals;
(3) aryl radicals having from 6 to 8 carbon atoms, such as the phenyl, tolyl or xylyl radicals.
As examples of cross-linking agents (B), representative are those corresponding to the following formulae:
CH.sub.3 Si(OCOCH.sub.3).sub.3
C.sub.2 H.sub.5 Si-(OCOCH.sub.3).sub.3
CH.sub.2 ═CHSi(OCOCH.sub.3).sub.3
C.sub.6 H.sub.5 Si-(OCOCH.sub.3).sub.3
CH.sub.3 Si[OCOCH (C.sub.2 H.sub.5)(CH.sub.2).sub.3 -CH.sub.3 ].sub.3
CF.sub.3 CH.sub.2 CH.sub.2 Si(OCOC.sub.6 H.sub.5).sub.3
CH.sub.3 Si(OCOC.sub.6 H.sub.5).sub.3 ##STR1##
It is clear that in the compositions of the invention the components (A) and (B) can be replaced with the devolatilized products emanating from the stoichiometric reaction of (A) with (B) according to the process described in French Pat. No. 1,200,348.
If a cross-linking agent (B) whose acyloxy radicals are of low molecular weight is employed, for example, methyltriacetoxysilane, there is formed, during the cross-linking, an organic acid of low molecular weight, which is generally volatile at the typical cross-linking temperatures and which is removed from the elastomer by evaporation and can then possibly be a source of corrosion phenomena and of loss of adhesion, particularly when the composition is deposited on metallic substrates. On the other hand, if use is made of a cross-linking agent (B) whose acyloxy radicals have a higher molecular weight, for example, methyltris(2-ethylhexanoyloxy)silane, 2-ethylhexanoic acid is formed, which is not volatile at the typical cross-linking temperatures and which remains in the elastomer; this represents a serious disadvantage, since the elastomer then has poor heat resistance and, in particular, a poor CS (compression set).
Furthermore, the acid remaining in the elastomer is also a source of corrosion phenomena and of loss of adhesion, particularly when the composition is deposited on metallic substrates.
One of the highly significant advantages of the use of the accelerators (D) according to the invention is precisely that, on account of their basicity, they neutralize the acids formed over the course of the cross-linking, eliminating the disadvantages inherently associated with the presence of these acids.
It is therefore particularly advantageous to use the accelerator (D) in an amount which is at least stoichiometric relative to the amount of acid which can form during the hardening of the composition.
With these cross-linking agents (B) there may be associated silanes, each of which has only two hydrolyzable groups; these silanes correspond to the formula:
R".sub.2 Si(OCOR').sub.2
in which the symbols R' have the meaning of the symbol R' in the formula
R.sub.p Si(OCOR').sub.4-p
and the symbols R" have the meaning of the symbol R in this same formula, or denote a tertiary butoxy radical of the formula (CH 3 ) 3 C--O--.
As examples of these silanes, representative are those of the following formulae:
(CH.sub.3).sub.2 Si(OCOCH.sub.3).sub.2
CH.sub.2 ═CH(CH.sub.3)Si(OCOCH.sub.3).sub.2
(C.sub.6 H.sub.5).sub.2 Si(OCOCH.sub.3).sub.2
[(CH.sub.3).sub.3 C-O].sub.2 Si(OCOCH.sub.3).sub.2
(CH.sub.3).sub.2 Si[OCOCH(C.sub.2 H.sub.5)(CH.sub.2).sub.3 CH.sub.3 ].sub.2
[(CH.sub.3).sub.3 CO].sub.2 Si[OCOCH(C.sub.2 H.sub.5)(CH.sub.2).sub.3 CH.sub.3 ].sub.2
The molar quantity which is employed of the silanes of the formula
R".sub.2 Si(OCOR').sub.2
relative to the quantity employed of the cross-linking silanes (B) of the formula R p Si(OCOR') 4-p is not narrowly defined, but it is necessary that it has an upper limit such that the mixture of both types of silanes always contains on average at least 2.5 -OCOR' groups per silicon atom.
Thus, when taking, for example, 1 mol of cross-linking silane (B) of the formula RSi(OCOR') 3 (with p=1), there must be associated with it at most 1 mol of the silane R" 2 Si(OCOR') 2 ; similarly, when taking 1 mol of the cross-linking silane (B) of the formula Si(OCOR') 4 (with p=0), there must be associated with it at most 3 mol of silane R" 2 Si(OCOR') 2 .
The main function of the silanes of the formula R" 2 Si(OCOR') 2 is to link the chains of the α,ω-di(hydroxy)diorganopolysiloxane polymers (A), which makes it possible to obtain elastomers having good physical characteristics starting from compositions containing polymers (A) whose viscosity is relatively low, for example, ranging from 700 to 5,000 mPa.s at 25° C.
The inorganic fillers (C) are employed in an amount of 0 to 150 parts by weight, preferably 5 to 120 parts by weight, per 100 parts by weight of α,ω-di(hydroxy)diorganopolysiloxane polymers (A). These fillers can be in the form of very finely divided particles whose mean particle diameter is less than 0.1 μm. Representative of such fillers are pyrogenic silicas and precipitated silicas; their specific surface is generally greater than 40 m 2 /g, and is most frequently in the range 150-200 m 2/ g.
These fillers can also be in the form of more coarsely divided particles, with a mean particle diameter greater than 0.1 μm. Representative of such fillers are ground quartz, diatomaceous silicas, calcium carbonate, calcined clay, rutile-type titanium oxide, the oxides of iron, zinc, chromium, zirconium or magnesium, the various forms of alumina (hydrated or not), boron nitride, lithopone or barium metaborate; their specific surface is generally below 30 m 2/ g.
The fillers (C) may have been surface-modified by treatment with the various organosilicon compounds conventionally employed for this application. Thus, these organosilicon compounds may be organochlorosilanes, diorganocyclopolysiloxanes, hexaorganodisiloxanes, hexaorganodisilazanes or diorganocyclopolysilazanes (French Pat. Nos. 1,126,884, 1,136,885 and 1,236,505, British Patent Specification No. 1,024,234). The modified fillers contain, in the majority of cases, from 3 to 30% of their weight of organosilicon compounds.
The fillers (C) may consist of a mixture of several types of fillers with different particle size distributions; thus, for example, they may consist of 30 to 70% of finely divided silicas having a specific surface greater than 40 m 2/ g and of 70 to 30% of more coarsely divided silicas having a specific surface below 30 m 2 /g.
The hydroxides of alkali metals or alkaline earth metals, which are employed as accelerators (D), are used in an amount of 0.01 to 7 parts by weight, preferably 0.05 to 5 parts by weight, per 100 parts by weight of the sum of the constituents (A), (B) and (C). They are preferably selected from among the hydroxides of lithium, barium, strontium and calcium, in anhydrous or hydrated form. In the anhydrous state these hydroxides correspond to the formulae:
LiOH, Ba(OH).sub.2, Sr(OH).sub.2, Ca(OH).sub.2
The hydrated hydroxides are represented more especially by the formulae:
LiOH·H.sub.2 O
Ba(OH).sub.2 ·H.sub.2 O
Ba(OH).sub.2 ·8H.sub.2 O
Sr(OH).sub.2 ·H.sub.2 O
Sr(OH).sub.2 ·8H.sub.2 O
It should be understood that the amounts of the hydroxides which are employed are based on the weight of the hydroxides proper, no account being taken of any water of crystallization. These hydroxides may be added as such or in the form of pastes, which facilitates their mixing with the other constituents. These pastes may consist of a silicone oil, such as an α,ω-bis(trimethylsiloxy)dimethylpolysiloxane polymer with a variable viscosity ranging, for example, from 500 to 100,000 mPa.s at 25° C. and, if appropriate, one or more inorganic fillers corresponding to at most 15% of the weight of the oil.
To increase the activity of the anhydrous or hydrated hydroxides, water or a compound which releases or evolves water during the cross-linking is preferably added, the water being present at the time of the cross-linking in an amount of at least 0.05% and preferably at least 0.10% relative to the weight of the hydroxides proper; the upper limit is not narrowly defined, but there is no advantage in exceeding 35% of the weight of the hydroxides proper because the excess water could produce, by accelerating the hardening too abruptly, harmful effects on the mechanical properties of the elastomers which are produced. Furthermore, such compositions which harden too quickly would be almost impossible to utilize.
The water may be added at any time during the preparation of the compositions according to the invention; in particular, it may be mixed directly with the hydroxides or with the pastes containing them. If care is taken, or if it is possible to heat the pastes containing, in particular, the hydroxides of lithium, barium or strontium, in the hydrated form, to a temperature above 100° C., for example, ranging from 100° to 180° C., for at least 30 minutes, then, very often, a part or all of the water of hydration is released. This water, dispersed in the paste, behaves like added water and further addition may therefore be found unnecessary.
The organopolysiloxane compositions according to the invention may contain, in addition to the constituents (A), (B), (C) and (D), hardening catalysts which are typically selected from among:
(i) metal salts of carboxylic acids, preferably organotin salts of carboxylic acids, such as dibutyltin diacetate and dilaurate,
(ii) products of reaction of organotin salts of carboxylic acids with titanic acid esters (U.S. Pat. No. 3,409,753),
(iii) organic derivatives of titanium and of zirconium, such as the titanic and zirconic acid esters (published French Application No. 82/13,505, filed July 30, 1982).
These catalysts for hardening are typically employed in a proportion from 0.0004 to 6 parts by weight, preferably from 0.0008 to 5 parts by weight, per 100 parts by weight of α,ω-di(hydroxy)diorganopolysiloxane polymers (A).
The organopolysiloxane compositions may also contain the usual adjuvants and additives, including, in particular, heat stabilizers. These latter materials, which, through their presence, improve the heat resistance of the silicone elastomers, may be selected from the salts, oxides and hydroxides of rare earths (and more especially from the ceric oxides and hydroxides) or from the oxides of titanium and of iron obtained, preferably, by combustion.
Advantageously, the compositions according to the invention contain from 0.1 to 15 parts by weight, and preferably from 0.15 to 12 parts by weight, of heat stabilizers per 100 parts by weight of α,ω-di(hydroxy)diorganopolysiloxane polymers (A).
As other additives, exemplary are compounds improving flame resistance; these are preferably selected from among organic phosphorus derivatives, organic halogen compounds, and organic and inorganic platinum derivatives.
In addition to the main constituents (A), (B), (C) and (D) and the above-mentioned additives, particular organopolysiloxane compounds may be introduced with the intention of influencing the physical characteristics of the compositions according to the invention and/or the mechanical properties of the elastomers produced by the hardening of these compositions.
These organopolysiloxane compounds are well known; they include, more especially:
(1f) α,ω-bis(triorganosiloxy)diorganopolysiloxane and/or α-(hydroxy)-ω-(triorganosiloxy)diorganopolysiloxane polymers, having viscosities of at least 10 mPa.s at 25° C., consisting essentially of diorganosiloxy units and at most 1% of monoorganosiloxy and/or siloxy units, the organic radicals bonded to the silicon atoms comprising methyl, vinyl or phenyl radicals, at least 60% of these organic radicals being methyl radicals and at most 10% being vinyl radicals. The viscosity of these polymers may reach several tens of millions of mPa.s at 25° C.; they therefore include oils with a fluid to viscous appearance and soft to hard gums. They are prepared according to the conventional techniques described in greater detail in French Pat. Nos. 978,058, 1,025,150, 1,108,764 and 1,370,884. Preferably use is made of α,ω-bis(trimethylxiloxy)dimethylpolysiloxane oils having a viscosity ranging from 10 mPa.s to 1,000 mPa.s at 25° C. These polymers, which act as plasticizers, may be added in an amount of at most 150 parts by weight, preferably of 5 to 120 parts by weight, per 100 parts by weight of α,ω-di(hydroxy)diorganopolysiloxane polymers (A).
(2f) branched, liquid methylpolysiloxane polymers having from 1.4 to 1.9 methyl radicals per silicon atom, consisting of a combination of units of the formulae:
(CH.sub.3).sub.3 SiO.sub.0.5
(CH.sub.3).sub.2 SiO and
CH.sub.3 SiO.sub.1.5
and containing from 0.1 to 8% of hydroxyl groups. Same can be obtained by hydrolysis of the corresponding chlorosilanes as taught by French Pat. Nos. 1,408,662 and 2,429,811. Preferably, use is made of branched polymers whose units are distributed according to the following ratios:
(CH.sub.3).sub.3 SiO.sub.0.5 /(CH.sub.3).sub.2 SiO=0.01 to 0.15
and
CH.sub.3 SiO.sub.1.5 /(CH.sub.3).sub.2 SiO=0.1 to 1.5.
These polymers may be added in an amount of at most 70 parts by weight, preferably of 3 to 50 parts by weight, per 100 parts by weight of α,ω-di(hydroxy)diorganopolysiloxane polymers (A). They confer thixotropic properties, particularly with the modified silicas.
(3f) diorganopolysiloxane oils blocked with hydroxyl groups and/or lower alkoxy groups having from 1 to 4 carbon atoms, having a low viscosity generally in the range 2 mPa.s to 4,000 mPa.s at 25° C. (if these oils are blocked only with hydroxyl groups, their viscosity is below 700 mPa.s at 25° C.); the organic radicals bonded to the silicon atoms of these oils are, as before, selected from among the methyl, vinyl or phenyl radicals, at least 40% of these radicals being methyl radicals and at most 10% being vinyl radicals. As chain-blocking lower alkoxy groups, exemplary are the methoxy, ethoxy, isopropoxy, n-propoxy, n-butoxy, isobutoxy and tertiary butoxy groups. The contents of hydroxyl and/or alkoxy groups generally range from 0.5 to 20%. These oils are prepared according to conventional techniques described in greater detail in French Pat. Nos. 938,292, 1,104,674, 1,116,196, 1,278,281 and 1,276,619. Preferably, α,ω-dihydroxydimethylpolysiloxane oils are used, having a viscosity of 10 to 300 mPa.s at 25° C., or α,ω-dihydroxymethylphenylpolysiloxane oils are used, having a viscosity of 200 to 600 mPa.s at 25° C., or α,ω-dimethoxy(or diethoxy)dimethylpolysiloxane oils are used, having a viscosity of 30 to 2,000 mPa.s at 25° C. They may be added in a proportion of at most 50 parts by weight, preferably of 2 to 40 parts by weight, per 100 parts by weight of α,ω-di(hydroxy)diorganopolysiloxane polymers (A). These oils make it possible to reduce the overall viscosity and are considered, according to the conventional term, as process aids.
(4f) hydroxylated organosilicon compounds selected from among compounds corresponding to the general formula:
Z'SiZ.sub.2 (OSiZ.sub.2).sub.w OH,
which are solid at ambient temperature. In this formula, the symbols Z, which may be identical or different, denote methyl, ethyl, n-propyl, vinyl or phenyl radicals; the symbol Z' denotes a hydroxyl radical or Z, and the symbol w is zero, 1 or 2. As specific examples of these compounds, representative are: diphenylsilanediol, methylphenylsilanediol, dimethylphenylsilanol, 1,1,3,3-tetramethyldisiloxanediol, 1,3-dimethyl-1,3-diphenyldisiloxanediol or 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxanediol. They may be added in a proportion of at most 30 parts by weight, preferably 0.5 to 20 parts by weight, per 100 parts by weight of α,ω-di(hydroxy)diorganopolysiloxane polymers (A). Same confer thixotropic properties on the medium, which generally is slightly gelled by their action. The α,ω-bis(triorganosiloxy)diorganopolysiloxane and/or α-(hydroxy)-ω-(triorganosiloxy)diorganopolysiloxane polymers described under (1f) may be replaced, wholly or partially, with organic compounds which are unreactive towards the constituents (A), (B), (C) and (D) and which are miscible at least with the α,ω-di(hydroxy)diorganopolysiloxane polymers (A). Exemplary of such organic compounds, representative are the polyalkylbenzenes obtained by alkylation of benzene with long-chain olefins, particularly olefins with 12 carbon atoms emanating from the polymerization of propylene. Organic compounds of this type appear, for example, in French Pat. Nos. 2,392,476 and 2,446,849.
The compositions according to the invention may, if appropriate, be used after dilution with liquid organic compounds, the diluents preferably being conventional commercially available materials selected from among:
(i) optionally halogenated, aliphatic, cycloaliphatic or aromatic hydrocarbons, such as n-heptane, n-octane, cyclohexane, methylcyclohexane, toluene, xylene, mesitylene, cumene, tetralin, perchloroethylene, trichloroethane, tetrachloroethane, chlorobenzene or ortho-dichlorobenzene;
(ii) aliphatic and cycloaliphatic ketones, such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone or isophorone;
(iii) esters, such as ethyl acetate, butyl acetate or ethylglycol acetate.
The amount of diluent is generally of little significance, generally being below 50%.
The preparation of the compositions according to the invention can take place in a single step, by mixing in a suitable reactor the combination of the components (A), (B), (C) and (D) and, if appropriate, the above-mentioned additives and adjuvants. These compounds may be added to the reactor in any order but it is, nevertheless, preferable to add the accelerators (D) after adding all of the other compounds such as to avoid a premature hardening of the mixture.
The preparation of the compositions can also take place in 2 steps. According to this technique, which is another object of the present invention, one-component compositions are first prepared by mixing, in the absence of moisture, the constituents (A), (B) and (C) and, if appropriate, the conventional additives and adjuvants. Same are stable on storage and harden only on exposure to moist air. Naturally, such compositions could, if appropriate, be employed alone and their hardening or cross-linking would then develop commencing from the surfaces in contact with the surrounding air and proceed progressively towards the interior of the mixture. The time for their complete hardening would be relatively long and would depend chiefly on the thickness of the deposited layers and on the humidity of the atmosphere surrounding the compositions. Generally, a period of 24 hours would thus be required at ambient temperature, with a humidity of 60%, to cross-link properly a layer 4 mm in thickness.
In a second step, the hardening accelerators (D) are added to these one-component compositions, and homogenized therewith, at the time of use. The compositions obtained, according to the invention, must be used quickly, since their hardening, in contrast to that of one-component compositions, develops essentially uniformly throughout the mixture. The time for their complete hardening is very variable, given that it depends on the nature and on the quantities of the accelerators (D) employed, on the presence or absence of water and on the form in which this water is introduced. By varying these various parameters it is possible to obtain hardening times ranging from a few minutes to 60 minutes or longer. The temperature is also an important parameter; in fact, variations in the temperature level have a very marked effect on the rate of hardening. If the temperature increases (the variations are positive) the hardening time is shortened; in the reverse case, such time is lengthened.
Thus, reductions in hardening time of one half, and sometimes much more, may be obtained by exposing the compositions to temperatures ranging, for example, from 50° to 200° C. instead of maintaining them at ambient temperature, namely, in the range of 15°-25° C.
Another object of the present invention is the use of the compositions with rapid hardening to produce seals.
The compositions according to the invention may be employed for many applications such as sealing in the building industry, the assembly of the most diverse materials (metals, plastics, natural and synthetic rubbers, wood, cardboard, crockery, brick, ceramics, glass, stone, concrete, masonry components), the insulation of electrical conductors, the coating of electronic circuits, or the preparation of molds employed in the manufacture of objects from synthetic resins or foams.
Furthermore, they are more especially suitable for the production of "in situ" seals employed in the automobile industry. These "in situ" seals encompass several types, namely, "crushed" seals, "formed" seals and "injected" seals.
The "crushed" seals are formed following the application of a pasty ribbon of the compositions to the zone of contact between 2 metal components to be assembled. The pasty ribbon is first deposited on one of the components and then the other component is immediately applied to the first; this results in a crushing of the ribbon before it is converted into elastomer. This type of seal is applicable to assemblies which usually do not need to be taken apart (oil sump seals, engine front end cover seals, etc.).
The "formed" seals are also obtained following the application of a pasty ribbon of the compositions to the zone of contact between 2 components to be assembled. However, after the deposition of the pasty ribbon on one of the components it is necessary to wait for the complete hardening of the ribbon to elastomer and the second component is applied to the first only after this time. As a result such an assembly can be easily taken apart since the component which is applied to that which has received the seal does not adhere to this seal. Furthermore, the seal, by virtue of its rubbery nature, adapts to all the irregularities of the surfaces to be sealed and, for this reason, there is no need (1) to machine carefully the metal surfaces which are to be placed in contact with each other and (2) to clamp under pressure the assemblies which are obtained; these factors make it possible to eliminate, to some extent, fixing seals, spacers, or ribs which are usually intended to stiffen and strengthen the components of the assemblies.
Since the compositions according to the invention harden quickly at ambient temperature, in the presence or the absence of moisture, in an enclosed environment or in free air, it follows that the "formed" seals (and also the other "in situ" seals) resulting from the hardening of these compositions can be produced under highly restricting conditions. They may, for example, be produced on the conventional assembly lines in the automobile industry which are equipped with an automatic apparatus for depositing the compositions. This automatic apparatus very frequently has a mixer head equipped with a deposition nozzle, the latter moving along the outline of the seals to be produced. The mixing head can receive the one-component polysiloxane composition and the accelerator, and can also have a third inlet allowing the introduction of a solvent for washing the equipment after use (cyclohexane, etc.).
The compositions produced and distributed by means of this apparatus must have a closely controlled hardening time, on the one hand to avoid solidification in the mixer head and on the other hand to obtain a complete cross-linking after the application of the pasty ribbon to the parts to be sealed. These "formed" seals are more especially suitable for the seals of rocker covers, gearbox covers, timing covers and even oil sumps, etc.
The injected seals are formed in an enclosed environment, often in cavities which are completely closed; the compositions placed in these cavities are rapidly converted into elastomers whose properties are identical to those of elastomers resulting from hardening of the compositions in free air. These seals can ensure, for example, the sealing of crankshaft bearings.
The compositions according to the invention are also suitable for the production of quick-hardening seals in areas other than automotive. They can thus serve to glue and to seal electrical switch boxes made of plastic, and to produce seals for vacuum cleaners and for steam irons.
The elastomers formed by the hardening of the compositions according to the invention have mechanical properties which are identical to those of elastomers produced from known one-component compositions, namely, the compositions formed by simple mixing of the constituents (A), (B) and (C) and, if appropriate, of conventional additives without the addition of accelerators (D). In particular, the compression sets are relatively low, for example, on the order of 8 to 35%; furthermore, the complete cross-linking measured by the Shore A hardness is obtained immediately following the cross-linking times mentioned earlier, which generally last from a few minutes to 60 minutes, sometimes longer but never more than 3 hours. In the case of one-component compositions, the complete cross-linking requires, under the most favorable of conditions, at least 10 hours or thereabouts. Furthermore, straightforward addition of water to the one-component compositions, while accelerating the hardening process appreciably, does not permit same to be cross-linked properly; in general, the final Shore A hardness is from 15 to 40% lower than that obtained without water or with the accelerator (D).
In order to further illustrate the present invention and the advantages thereof, the following specific examples are given, it being understood that same are intended only as illustrative and in nowise limitative.
EXAMPLE 1
A composition C 1 which hardens to an elastomer at ambient temperature was prepared by mixing the following constituents:
(1) 100 parts by weight of an α,ω-di(hydroxy)dimethylpolysiloxane oil having a viscosity of 4,000 mPa.s at 25° C.;
(2) 20 parts by weight of a pyrogenic silica having a specific surface of 200 m 2 /g;
(3) 20 parts by weight of ground quartz having a mean particle diameter of 5 microns;
(4) 20 parts by weight of rutile-type titanium dioxide having a mean particle diameter of 8 microns;
(5) 1 part by weight of an α,ω-di(hydroxy)methylphenylpolysiloxane oil having a viscosity of 350 mPa.s at 25° C.; and
(6) 6 parts by weight of methyl(triacetoxy)silane.
This composition C 1 was dispersed in 72 parts of anhydrous cyclohexane. A homogeneous dispersion D 1 was thus obtained, containing approximately 70% of the composition C 1 . This dispersion was stored in moistureproof aluminum containers; it displayed no change in appearance after 6 months storage.
In addition, 7 pastes were prepared, each containing a hardening accelerator for the composition C 1 . The nature of the components, together with the quantities employed, expressed in % by weight, of these pastes, are reported in the following Table I:
TABLE I__________________________________________________________________________CONSTITUENTS OF EACH PASTE A.sub.1 A.sub.2 A.sub.3 A.sub.4 A.sub.5 A.sub.6 A.sub.7__________________________________________________________________________α,ω-bis(trimethylsiloxy)- 69.8 79.7 71.8 68.9 64.3 78.1 89.4dimethylpolysiloxane oilhaving a viscosity of30,000 mPa · s at 25° C.Pyrogenic silica having 0.8 0.9 0.8 0.8 0.7 3.1 5.3a specific surface of200 m.sup.2 /gCa(OH).sub.2 (accelerator) 28.8 19.1 27.1 30.1 35LiOH.H.sub.2 O (accelerator) 5 (or 2.85 of LiOH)Ba(OH).sub.2.8H.sub.2 O (accelerator) 18.8 (or 0.2 of Ba(OH).sub.2)Added water 0.60 0.3 0.3 0.2 0 0 0.3__________________________________________________________________________
10 g of one of the 7 pastes were first introduced into a cylindrical plastic container, 500 cm 3 in volume, followed by 200 g of the dispersion D 1 ; the contents of the container were immediately mixed with a spatula and this mixing was continued for approximately 1 minute, 15 seconds; the mixture was then quickly poured into a cylindrical glass flask, 125 cm 3 in volume, equipped with a cover pierced by 2 holes, one of the holes allowing the passage of a stream of dry nitrogen, the other serving for the passage of a No. 7 spindle of a Brookfield viscometer.
After closing the cover, installing the viscometer spindle and connecting the supply for a stream of dry nitrogen, the viscometer spindle was started and rotated at the rate of 2.5 rpm. The time interval between the start of mixing with the spatula and the start of the rotation of the viscometer spindle was 2 minutes.
The change in the viscosity of the mixture contained in the glass flask was traced as a function of time and the rotation of the spindle was terminated when the viscometer still showed a reading indicating a viscosity of 16.10 5 mPa.s at 25° C.
TABLE II__________________________________________________________________________PASTES ADDED TO THEDISPERSION D.sub.1 A.sub.1 A.sub.2 A.sub.3 A.sub.4 A.sub.5 A.sub.6 A.sub.7__________________________________________________________________________Quantity of the accelerator 2.05 1.36 1.93 2.15 2.5 0.73 0.20in % of the composition C.sub.1Quantity of added water in 2.08 1.57 1.1 0.66 0 0 10.52% of the acceleratorTime to reach 16 · 10.sup.5 19 min 45 min 20 min 45 min 85 min 10 min 11 minmPa · s at 25° C. 30 sec 30 sec__________________________________________________________________________
It was found that the change in the viscosity in the body of the mixture was distinct in all cases. It varied, however, as a function of the nature of the accelerator and of the quantity which was used, as well as of the quantity of water added.
EXAMPLE 2
A paste was prepared by mixing:
(i) 100 parts by weight of an α,ω-bis(trimethylsiloxy)dimethylpolysiloxane oil having a viscosity of 30,000 mPa.s at 25° C.;
(ii) 2 parts by weight of a pyrogenic silica having a specific surface of200 m 2 /g; and
(iii) 17.6 parts by weight of lime of the formula Ca(OH) 2 having a mean particle diameter of 6 μm.
5 parts of this paste (corresponding to 0.73 part of lime) were blended into 100 parts of the composition C 2 , itself obtained by mixing the following constituents:
(1) 100 parts by weight of an α,ω-di(hydroxy)dimethylpolysiloxane oil having a viscosity of 7,000 mPa.s at 25° C.;
(2) 10 parts by weight of a pyrogenic silica having a specific surface of 150 m 2 /g;
(3) 85 parts by weight of a diatomaceous silica having a mean particle diameter of 5 microns;
(4) 4 parts by weight of an α,ω-di(hydroxy)dimethylpolysiloxane oil having a viscosity of 50 mPa.s at 25° C.;
(5) 5 parts by weight of methyltriacetoxysilane; and
(6) 0.004 part by weight of butyl titanate.
The period of blending of the paste with the composition C 2 was approximately 2 minutes. The composition obtained was immediately spread out in the form of a layer 4 mm thick on polyethylene plates arranged in 3 batches.
One batch of plates was placed in an enclosure heated to a temperature of 25° C., another batch in an enclosure heated to a temperature of 50° C. and the third batch in an enclosure heated to a temperature of 100° C.
The layer of the composition deposited on each plate was converted into a rubbery strip whose Shore A hardness was determined as a function of time. The time was measured from the moment when the plates were placed into the heated enclosures. The results are as follows:
Plates exposed to a temperature of 25° C.
The Shore A hardness was measurable after 25 minutes and reached its maximum value of approximately 50 after 90 minutes.
Plates exposed to a temperature of 50° C.
The Shore A hardness was measurable after 10 minutes and reached its maximum value after 60 minutes.
Plates exposed to a temperature of 100° C.
The Shore A hardness was measurable after 5 minutes and reached its maximum value after 20 minutes.
These results evidence that, for a specified composition, a wide range of vulcanization times is available depending on the temperature.
Furthermore, the composition C 2 was stored in a moistureproof container. It displayed no signs of change after 1 year's storage.
EXAMPLE 3
A composition which hardens at ambient temperature was prepared by mixing the following constituents:
(1) 100 parts by weight of an α,ω-di(hhydroxy)dimethylpolysiloxane oil having a viscosity of 3,500 mPa.s at 25° C.;
(2) 14 parts by weight of a pyrogenic silica having a specific surface of 200 m 2 /g;
(3) 14 parts by weight of diatomaceous silica having a mean particle diameter of 5 microns; and
(4) 1.65 parts by weight of rutile-type titanium dioxide having a particle diameter of 8 microns.
The traces of water were removed by heating at 120° C. under slightly reduced pressure and, after cooling, 10 parts by weight of methyltris(2-ethylhexanoyloxy)silane were added thereto.
To this composition were added:
(5) 30 parts by weight of an α,ω-bis(trimethylsiloxy)dimethylpolysiloxane oil having a viscosity of 20 mPa.s at 25° C., and the composition was divided into 4 portions of 100 g. 2.40, 3.60 and 4.80 g of lime of the formula Ca(OH) 2 having a mean particle diameter of 6 μm were added, respectively, to three of these portions. 3 compositions designated D 1 , D 2 and D 3 were thus obtained and the fourth portion without lime was designated C 2 .
The compositions C 2 , D 1 , D 2 and D 3 were immediately spread out in the form of a layer 2 mm in thickness on polyethylene plates and the time required to permit manual separation and complete removal of the layer of elastomer from the polyethylene plate was then measured. After the elastomer had been permitted to cross-link for 5 days under ambient conditions and once it had hardened, the 2-ethylhexanoic acid contained in the elastomer and formed by hydrolysis of the methyltris(2-ethylhexanoyloxy)silane employed as cross-linking agent was extracted with toluene. n-Butanol was added to the extract to give a 50/50 mixture by volume of toluene and butanol, and then a colored indicator reflecting the presence of acidity was added.
A determination of the number of millimoles of 2-ethylhexanoic acid extracted with the toluene per 100 g of elastomer C 2 , D 1 , D 2 and D 3 can be carried out by titration with alcoholic potassium hydroxide. The results obtained for the separation times and the quantity of acid remaining in the elastomer are reported in the following Table III:
TABLE III__________________________________________________________________________ Quantity of 2-ethylhexanoicNature of the composition Speed of cross- Time to separate acid in millimoles in 100 gconverted to elastomer linking the elastomer layer of elastomer__________________________________________________________________________C.sub.2 with 0 g Ca(OH).sub.2 Slow setting 24 hours 39 starting from the surfaceD.sub.1 with 2.4 g of Ca(OH).sub.2 Fast setting 30 minutes 7.7per 100 g of D.sub.1 throughout the massD.sub.2 with 3.60 g of Fast setting 15 minutes TracesCa(OH).sub.2 per 100 g of D.sub.2 throughout the massD.sub.3 with 4.80 g of Fast setting 15 minutes 0Ca(OH).sub.2 per 100 g of D.sub.3 throughout the mass__________________________________________________________________________
The above Table evidences that the presence of lime makes it possible to obtain a very fast setting of the composition and to neutralize the 2-ethylhexanoic acid.
While the invention has been described in terms of various preferred embodiments, the skilled artisan will appreciate that various modifications, substitutions, omissions, and changes may be made without departing from the spirit thereof. Accordingly, it is intended that the scope of the present invention be limited solely by the scope of the following claims. | Organopolysiloxane compositions which rapidly harden to the elastomeric state, even at ambient temperatures, are comprised of (i) a polyhydroxylated polysiloxane, (ii) a polyacyloxysilane cross-linking agent therefor, and (iii) a hardening accelerator comprising an alkali or alkaline earth metal hydroxide. The subject compositions are useful, inter alia, for providing elastomeric seals. | 2 |
REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part of U.S. patent application Ser. No. 08/201,682, entitled "Anti-inflammatory and Infection Protective Effects of Sesamin-Based Lignans", filed Feb. 25, 1994, on an application of the presents inventors, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to dietary manipulation for the treatment of disease. More particularly, the present invention relates to the use saponins in an enteral formulation for treatment of infection and inflammation.
The last decade has seen an explosion in the exploration of the interaction between diet and disease. In particular, the effects of various amino acids and lipids in the diet on a variety of conditions including heart disease, hypercatabolic states, liver disease, immunosupresssion, and infection treatment have been uncovered. Often, the effects are far removed from the norm and as such are unexpected. One of the most important developments of this type has been the discovery that by changing the dietary lipid content, positive effects in health treatment beyond plasma fat modification could be achieved. While the early work in modifying lipid content and type in diet came from an understanding that saturated fats cause particular problems in heart disease, later work determined that not just the use of polyunsaturated fats but also the type of polyunsaturated fat was important.
There are three major families of polyunsaturated fatty acids: ω3, ω6 and ω9. The names are based on location of the closest double bonds to the methyl end of the fatty acid; that is, if the closest double bond is between the third and fourth carbon atoms from the methyl group, the molecule is classified as an ω3 fatty acid while if the double bond is between the 6th and 7th carbon atoms, it is classified as an ω6 fatty acid. Mammals can desaturate or elongate fatty acid chains but cannot interconvert fatty acids from one family to another. The most important dietary fatty acids are the C 18 and C 20 fatty acids, primarily linoleic (C18:2ω6), linolenic acid (C18:3ω3), γ-linolenic acid (C18:3ω6) and dihomo-γlinolenic acid (C20:3ω6). Manipulation of the content of these fatty acids changes the ratio of arachidonic, eicosapentanoic, and decahexanoic acids (C20:4ω6, C20:5ω3, and C22:6ωreceptively) and can cause far reaching effects in terms of immunosuppression, response to hypercatabolic states, and infection. For example, U.S. Pat. No. 4,752,618, issued Jun. 21, 1988 on an application of Mascioli et al., the disclosure of which is incorporated herein by reference, discloses the beneficial effects of ω3 fatty acids in the treatment of infection. In U.S. Pat. No. 5,260,336, issued Nov. 3, 1993 on an application of Forse et al., the disclosure of which is also incorporated herein by reference, concerns a method of minimizing the effect of catabolic illness or infection using an oil such as olive oil which is rich in ω9 fatty acids. Other similar patents and articles, such as U.S. Pat. No. 4,810,726, issued. Mar. 7, 1989 on an application of Bistrian et al., the disclosure of which is also incorporated herein by reference, disclose other means of treating illness using fatty acid dietary manipulation.
The "culprit" in many diets appears to be the high level of ω6 fatty acids, primarily linoleic acid, a precursor for the formation of arachidonic acid which is a substrate for the production of pro inflammatory dienoic eicosanoids including PGE 2 and TxA 2 which can lead to elevated levels of thromboxane A 2 and related prostanoids. Elevation of these prostanoids has been linked to problems in response to endotoxin challenge and other infection states. Accordingly, the new wave in diets has been to minimize the ω6 fatty acid content (which, although an essential fatty acid, is not needed in the quantities found in most commercial oils) while maximizing the ω3 fatty acids (e.g., fish oil) and ω9 fatty acids (e.g., olive oil). Similarly, although sesame oil has long been promoted as having medicinal benefits, it is only recently that the effects have been traced to sesamin (and its related lignans) in the sesame oil. In fact, U.S. patent application Ser. No. 08/201,682, filed Feb. 25, 1994, on an application of the same inventors, discloses that sesamin can promote resistance to infection and reduce inflammation. Thus, materials which modify lipid content in the diet may have important and surprising health effects.
The present invention uses saponins to treat infection and reduce inflammation. It has also been found that these saponins can work in concert with other agents such as fish oils to provide quicker (and consequently better) protection against infection.
Saponins are surface active triterpene or sterol glycosides. Although the saponins are found mainly in plants, they have also been found in certain marine animals such as echinoderms like starfish and sea cucumbers. Most saponins are non-toxic when taken orally, but many are toxic upon i.m. or i.v. injection. Saponins are most often ingested by man in legumes such as chick peas and soy beans. In fact, it has been theorized that legumes rich in saponins may reduce the threat of heart disease based, in part, on the finding that saponins can reduce plasma cholesterol levels in animals. See, e.g., Newman et al., Poultry Science 37 42-45(1957).
However, the main medicinal use for saponins appears to be their properties as immunostimulating substances or adjuvants. Reports of immunopotentiating advantages using saponins go back over fifty years (see, e.g., Thibault and Richou, C.R. Soc. Biol. 121 718-721 (1936)). While saponins are available from many sources, much of the work on immunostimulation has used saponins derived from the inner bark of the South American soaptree, Quillaja saponaria Molina. These saponins, normally designated as the Quill A saponins, remain the principal medicinal saponins in use today.
Although many other medicinal uses have been hypothesized for saponins, there has been no systematic proof that any effects other than use as an adjuvant is medicinally feasible. However, saponins have been found in some plants used in traditional or folk remedies. For example, saponins are present in ginseng which has long been used in Asia for treatment of a variety of conditions. Similarly, other homeopathic remedies also may contain saponins. The recent interest in homeopathic remedies has lead to a further exploration of the properties of materials such as saponins.
Accordingly, an object of the invention is to provide an enteral dietary supplement containing saponins.
Another object of the invention is to provide a means of treating infection and/or inflammation using saponins.
A further object of the invention is to provide a dietary supplement useful in improving the effects of ω3 fatty acids on treatment of infection.
An additional object of the invention is to provide a dietary supplement useful in improving the uptake of polyunsaturated fatty acids (e.g., EPA and DHA) in tissue.
A still further object of the invention is to provide a method of treating infection and/or inflammation using dietary manipulation.
These and other objects and features of the invention will be apparent from the following description and the claims.
SUMMARY OF THE INVENTION
The present invention features enteral formulations for treatment of inflammation and infections, as well as methods of treatment itself. These formulations are based on the surprising properties of saponins, a material that is often used as an adjuvant but not as the medicament itself. The saponins are effective with standard enteral formulations such as safflower oil dietary supplements and appear to have additive, or even synergistic, effects with ω3 fatty acid formulations such as those derived from fish oil or linseed oil. The saponins can also be used with sesamin and related lignans from sesame oil to provide particularly advantageous diets. These saponins could also be included in other food products such as margarines and butter as well as dietary supplements. Such other food products and dietary supplements are included in the enteral formulations herein.
More particularly, the present invention features an enteral formulation adapted for treatment of infection or inflammation in a patient which includes an effective amount of a saponin as an active ingredient. The term "effective amount" means a sufficient amount of the saponin to cause the clinical effect in terms of anti-inflammation and/or anti-infection properties. This effective amount can vary due to a number of factors including type of saponin and personal metabolism. For Quill A, one of the most readily available saponins, this effective amount appears to be about 0.1% -1.0% by weight of the enteral diet, with a 0.25% amount being preferred. For other saponins, with different purification and potency, different effective amounts may easily be determined.
The enteral formulation useful in the invention may include particular fatty acids or other materials which have similar anti-inflammatory properties. For example, the previously cited U.S. Pat. No. 4,752,618 discloses that ω3 fatty acids may have anti-infection properties. An enteral formulation which includes these ω3 fatty acids in conjunction with the saponins is, therefore, advantageous. Preferred sources of ω3 are the fish oils, and linseed (flax) oil, most preferably the oils derived from cold water fish which have at least 10% of their lipid content in ω3 fatty acids and flax oil which contains approximately 55% linolenic acid (18:3 ω3). Examples of the useful cold water fish include menhaden and sardine. In fact, as is shown later in the examples, the addition of saponins to an enteral formulation containing ω3 fatty acids causes less lagtime until the beneficial effects of the ω3 fatty acids occur and increased uptake of ω3 fatty acids into tissue. These saponins may also yield beneficial effects with other dietary oils such as borage oil, black currant seed oil, canola oil, and rapeseed oil.
Another additive useful in an enteral formulation is a lignan of the sesamin family. Previously cited U.S. patent application Ser. No. 08/201,682 discloses the anti-infection and anti-inflammatory properties of these lignans. The lignans preferred include sesamin, episesamin, sesaminol, espisemsaminol, and sesamolin. A combination therapy including these lignans and the saponins may be particularly advantageous.
Any enteral formulation preferably includes essential amino acids, essential fatty acids, and/or essential vitamins and minerals. The enteral formulations of the present invention may be in the form of a dietary supplement or used as a total enteral feeding regimen. If the later, these essential nutrients are required while even in a supplement, the addition insures that the patient is obtaining these nutrients.
The enteral formulation such as is previously described are particularly useful in treating infection and inflammation. In fact, these formulations may be used in at risk patients to prevent possible infection or inflammation. Further, when used with the other formulations such as the ω3 fatty acids, the time to effective action may be reduced.
The following description and non-limiting examples further elucidate the invention.
DETAILED DESCRIPTION
The present invention provides an enteral formulation useful in treating inflammation and/or infection. This enteral formulation includes an effective amount of a saponin such as Quill A, possible in conjunction with a diet rich in ω3 fatty acids or a diet containing a lignan such as sesamin. As such, saponins show remarkable promise as additives in treating infection states, particularly acute infections e.g., sepsis.
The following examples, which all use saponins in enteral diets, further explain the invention.
EXAMPLE 1
This example explains the procedure used to create the diets used for test purposes. The two diets basic diets were made, a safflower oil diet (SO) which had large quantities of ω6 fatty acids, primarily in the form of linoleic acid, and a fish oil (FO) diet which had a large percentage of ω3 fatty acids. The oil portion of the safflower oil diet was made by taking 52 g of safflower oil (SVO Specialty Products, Culberton, Mont.) and mixing it with 88 g of palm oil and 10 g of Trisum, a high oleic sunflower oil. The fish oil diet used menhaden oil, which has 32% ω3 polyunsaturated fats, primarily in the form of eicosapentanoic acid (EPA) and docosahexaenoic acid (DHA), as the fish oil. The fish oil portion of the fish oil diet was made by blending 8 g safflower oil, 125 g of fish oil, 35 g of palm oil and 10 g of Trisum. These physical mixtures of oils were prepared to maintain the saturated, monounsaturated, and polyunsaturated fat contents identical in both experimental diets. However, the polyunsaturated fatty acids in the former is ω6 type and in the latter is ω3. One hundred fifty grams of each oil mixture was added to 850 g of AIN-76, a fat-free basal diet which contained essential minerals and vitamins. For each 1000 g of either enteral diet, 15% by weight was in form of fat with the fat calories being approximately 30% of the total (as recommended by the Surgeon General).
The combination of the fat and the AIN-76 fat-free basal diet had 0.05% t-butyl hydroxy tolulene added as an antioxidant, and the diets were stored in individual daily rations, flushed with nitrogen to minimize oxidation, at 4° C. The animals were fed ad libium every day before dusk.
Separate groups of Balb/c mice were maintained on the safflower oil diet, the fish oil diet, and the two diets supplemented with saponins. Plasma was sampled at 4, 7 and 10 days and the fatty acid compositions of phospholipids in the plasma were determined by gas chromatography following a thin layer of chromatography.
The relative mole percent of individual fatty acids (including linoleic acid and arachidonic acid) incorporated into the plasma phospholipids and the tissues were determined. There was substantially no difference in the fatty acid pattern for the safflower oil diet vs. the safflower oil with saponin diet but the fish oil diet vs. fish oil with saponin diet was another matter. At day 4, the relative percentages of eicosapentanoid acid and decahexenoic acid (DHA) were twice as high in the plasma phospholipids of mice consuming the fish oil with saponins diet as compared with the fish oil alone. By day 7, the differences disappeared. However, the levels of tissue polyunsaturated ω3 fatty acids increased at day 7 and remained elevated until day 10.
EXAMPLE 2
In this example, Balb/C mice were maintained ad libium on one of the diets described in Example 1, the safflower oil diet, for three weeks. Safflower oil diets are commonly used for enteral nutrition. A first group received just the safflower oil diet (SO) while the second group had the safflower oil diet supplemented with 0.25% saponins (SO+). There were twenty animals in the first group and seventeen in the second group.
At the end of three weeks, all the animals in both groups underwent cecal ligation and puncture. To perform this procedure, the mice were anaesthetized and then shaved over the anterior abdominal wall. A midline incision, approximately 2 cm long, was made, sufficient to expose the cecum and adjacent intestine. With a 3-0 silk suture, the cecum was tightly ligated at its base without causing bowel obstruction. The cecum was then punctured twice with a 22 gauge needle, gently squeezed to exude feces and to insure that the two puncture holes did not close. The abdominal incision was then closed and 1 ml of saline was administered subcutaneously for fluid resuscitation. This cecal ligation and puncture is a widely accepted form of infection model to resemble abdominal sepsis. See, e.g., C. Baker et al., "Evaluation of factors affecting mortality rate after sepsis in a murine cecal ligation and puncture model," Surgery (August 1983), pp. 331-335. Survival of the mice is the normal measure of treatment effectiveness.
In addition, ten animals were fed each diet to serve as controls and were a sham operated; this means, that the abdominal operation was performed but cecal ligation and puncture was not carried out.
TABLE 1______________________________________Diets 24 hours 48 hours 72 hours 96 hours______________________________________SAFFLOWER 20 (100) 14 (70) 6 (30)* 4 (20)*OIL (SO)SAFFLOWER 17 (100) 16 (94) 15 (88)** 15 (88)**OIL +SAPONINS(SO+)______________________________________
Table 1 shows the survival on the SO diet vs. the SO+ diet. While all the animals in each group were alive at 24 hours, the number of animals alive at 48, 72 and 96 hours decreases rapidly for the safflower oil group while the group being treated with the safflower plus saponin diet shows very little mortality. The first number is the number of animals remaining alive while the second is a percent remaining alive. At 72 hours, the number of animals surviving is statistically significant (p<0.05 using a student t test) while at 96 hours, the data are even better (p<0.01). The groups of animals consuming the diets supplemented with saponins showed no mortality.
Accordingly, this shows that adding the saponins to a safflower oil diet has significant anti-infection effects.
EXAMPLE 3
The beneficial effects of feeding diets enriched with safflower oil (15 wt %=30% total calories) supplemented with or without saponins (0.25%) was tested in an infection model. Groups of 10 female Balb/c mice, 6-8 weeks old, were fed the two diets for 3 weeks. The plasma levels of thrombxane B 2 (TBX2), tumor necrosis factor (TNF)-α and other proinflammatory mediators were determined in plasma 90 minutes after an interperitonial injection of lipopolysacchride (LPS) (20mg/kg).
TABLE 2______________________________________SAFFLOWER OIL (SO) SO + SAPONINS______________________________________TXB.sub.2 466 ± 98 257 ± 48#(pg/ml*)TNF-α 380 ± 100 100 ± 40#(pg/ml*)______________________________________ *means ± S.D of determinations following LPS i.p injection in mice (n 10 in each group.) #p < 0.05.
The increase in survival of animals in Example 2 were associated with significantly lower concentrations (45%) of the LPS-induced TBX 2 and TNF-α in the circulation while the AA content, a 5precursor for the formation of dienoic eicosanoids (such as TBX 2 ), was unchanged for the groups of mice fed safflower oil diets containing saponins as described in Example 1. These data suggest that saponins possess anti-inflammatory properties which may include inhibiting the activities of phospholipase A 2 or cyclooxygenase enzymes. Further, the ability of saponins to markedly lower (74%) the LPS-induced in vivo production of TNF-α suggests a possible mechanism by which dietary saponins confer protection against infection irrespective of the type of polyunsaturated fatty acid in the diet. These data indicate that inclusion of saponins in an enteral formulation containing different types of polyunsaturated fatty acids (ω3, ω6, or ω9) could benefit critically ill patients.
EXAMPLE 4
In this experiment, Balb/c mice were again maintained on either the safflower oil diet alone or the safflower oil diet supplemented with 0.25% of the saponin Quill A. Spleens were isolated aseptically at 1, 2 and 3 weeks and single cell suspensions were prepared. One million spleen cells were stimulated with either concanavalin A (Con A-1 mg/ml) or lyopopolysacchride (lps-10 μg/ml) for twenty-four hours, both of which are known to induce the production of proinflammatory mediators. Cell free supernatants were collected and the amounts of prostaglandin E 2 (PGE2) were determined by immunoassay. The PGE 2 levels in the supernatants from the spleen cells of the animals treated with the saponins were significantly lower (see Table 2) than those with the safflower oil diet alone on day 7 (p<0.05). After two or three weeks of feeding, the mean concentrations of the PGE 2 were not significantly different. These data suggest the saponins exhibited anti-inflammatory properties and that feeding safflower oil diets with saponins may have selected a cell population which participated in defending the host against infection.
TABLE 3______________________________________ Con A LPS______________________________________SAFFLOWER OIL 114 ± 20 248 ± 32(SO)SAFFLOWER OIL + 70 ± 13 153 ± 11SAPONINS (SO+)______________________________________
All valves in pg/ml at day 7.
Since it is known that fish oil diets will provide anti-infection properties, the ability of the saponin addition to provide a more rapid incorporation of ω3 fatty acids in the fatty acid profiles of the phospholipids in the plasma and in the tissues suggest that this may speed the action of the fish oil. If so, this effect may be important in treating infection, particularly with post-operative patients.
The foregoing examples are merely exemplary and one skilled in the art may determine other enteral diets and methods of treatment using such an enteral diet which falls within the scope of the present invention. The invention is defined not by these examples but rather by the following claims. | The present invention features saponin containing enteral formulations for treatment of infection and inflammation. These saponin containing formulations are particularly useful in conjunction with oils rich in ω3 polyunsaturated fatty acids such as fish oils and flax oil but also show benefits with ω6 rich oils such as borage oil, black currant seed oil, canola oil and rapeseed oil. These formulations may also contain a lignan from the sesamin family. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of International application No. PCT/JP2013/062558, filed Apr. 30, 2013, which claims priority to Japanese Patent Application No. 2012-176863, filed Aug. 9, 2012, the entire contents of each of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a laminated ceramic capacitor and a manufacturing method therefore, and more particularly, relates to a laminated ceramic capacitor including: a laminated body including a plurality of dielectric ceramic layers stacked and a plurality of internal electrodes provided at a plurality of interfaces between the dielectric ceramic layers; and an external electrode formed on the outer surface of the laminated body and electrically connected to the internal electrodes, and a manufacturing method therefore.
BACKGROUND OF THE INVENTION
In recent years, with the reduction in size and weight for electronic devices, laminated ceramic capacitors have been used widely which are small in size and capable of acquiring high capacitance. These laminated ceramic capacitors have, for example, as shown in FIG. 2 , a structure including: a laminated body 10 including a plurality of dielectric ceramic layers 11 stacked, and a plurality of internal electrodes 12 provided at a plurality of interfaces between the dielectric ceramic layers 11 ; and a pair of external electrodes 13 a , 13 b provided on both end surfaces of the laminated body 10 so as to be brought into electrical continuity with the internal electrodes 12 alternately exposed at the opposite end surfaces.
Furthermore, in these laminated ceramic capacitors, dielectric ceramic materials which have a high dielectric constant and contain, as their main constituent, a perovskite-type compound containing Ba, Ti, etc. have been used widely as the material constituting the dielectric ceramic layers.
Furthermore, dielectric ceramic compositions as described in Patent Document 1 have been proposed as such dielectric ceramic materials.
This dielectric ceramic composition contains, as its main constituent, a composition represented by a general formula: n(BaO x —SrO y —CaO z ) (Zr m Ti 1-m )O 2 (where x+y+z=1, x, y, z, m, and n represent molar ratios) in which x, y, and z are, in terms of molar ratio, in the composition ranges shown in Table 1 of Patent Document 1 where a, b, c, d, and e are surrounded by straight lines, and m and n are in the ranges of m≧0.95 and 0.8≧n≧1.04, and contains as additives, 0.1 to 0.7 wt % of Mn 3 O 4 , 0.5 to 3.0 wt % of BaSiO 3 , 0.01 to 0.07 wt % of V 2 O 5 , and further 0.05 to 0.30 wt % of Al 2 O 3 added with respect to 100 wt % of the main constituent.
However, in the case of the conventional dielectric ceramic composition mentioned above, because grain growth of crystal grains by firing is likely to be promoted rapidly, there is a problem that in particular, in such a thin-layer region having a thickness of the dielectric ceramic layer (the thickness of a dielectric ceramic layer sandwiched between internal electrodes for the formation of capacitance) of 3 μm or less, the grain sizes (grain sizes) of crystal grains with respect to the thickness of the dielectric ceramic layer are excessively increased to not only increase the initial short circuit ratio, but also increase the time degradation in insulation resistance in a high-temperature load test, thereby shortening the high-temperature load life.
Patent Document 1: Japanese Patent Application Laid-Open No. 2001-294481
SUMMARY OF THE INVENTION
The present invention is intended to solve the problem mentioned above, and an object of the present invention is to provide a highly reliable laminated ceramic capacitor which undergoes a small change in insulation resistance with time in a high-temperature load test, and has excellent resistance to insulation degradation.
In order to solve the problem mentioned above, a laminated ceramic capacitor according to the present invention is:
a laminated ceramic capacitor including:
a laminated body including a plurality of dielectric ceramic layers stacked, and a plurality of internal electrodes provided at more than one interface of the interfaces between the dielectric ceramic layers; and
an external electrode formed on the outer surface of the laminated body and electrically connected to the internal electrodes,
and characterized in that:
the laminated body contains:
Si, Mn, Al, V and a perovskite-type compound containing Sr, Ba, Zr, Ti, and optionally containing Ca;
when the total content of Zr and Ti is regarded as 100 parts by mol,
(a) the total content m (parts by mol) of Sr, Ba, and Ca meets 100≦m≦105;
(b) the Si content a (parts by mol) meets 0.1≦a≦4.0;
(c) the Mn content b (parts by mol) meets 0.1≦b≦≦4.0;
(d) the Al content c (parts by mol) meets 0.01≦c≦3.0;
(e) the V content d (parts by mol) meets 0.01≦d≦0.3;
(f) the molar ratio w (Sr/(Sr+Ba+Ca)) of the total of Sr, Ba, and Ca to Sr meets 0.60≦w≦0.95;
(g) the molar ratio y (Ca/(Sr+Ba+Ca)) of the total of Sr, Ba, and Ca to Ca meets 0≦y≦0.35;
(h) the molar ratio z (Zr/(Zr+Ti)) of the total of Zr and Ti to Zr meets 0.92≦z≦0.98;
the total of the value of the w and the value of the y meets the relationship of 0.6≦w+y≦0.95; and
the plurality of dielectric ceramic layers each have crystal grains; and the crystal grains are 1.2 μm or less in average grain size.
It is to be noted that a dielectric ceramic composition in a composition range containing a lot of Sr and Ba (in particular, Sr) at the A site of the perovskite-type compound represented by the general formula ABO 3 as mentioned above, with a low Ca content or without any Ca contained, is used as the dielectric ceramic constituting the laminated ceramic capacitor, the sintered dielectric ceramic layers are likely to undergo an increase in linear expansion coefficient, and brought closer to the linear expansion coefficient of the internal electrodes, and there is thus a tendency to suppress internal stress, and improve, in particular, the moisture-resistance load life (insulation degradation life in a moisture-resistance load test), for example, when the composition is applied to a laminated ceramic capacitor including Ni internal electrodes.
Furthermore, the laminated ceramic capacitor according to the present invention is:
a laminated ceramic capacitor including:
a laminated body including a plurality of dielectric ceramic layers stacked, and a plurality of internal electrodes provided at more than one interface of the interfaces between the dielectric ceramic layers; and
an external electrode formed on the outer surface of the laminated body and electrically connected to the internal electrodes,
and characterized in that:
the laminated body contains:
Si, Mn, Al, V and a perovskite-type compound containing Sr, Ba, Zr, Ti, and optionally containing Ca,
when the total content of Zr and Ti is regarded as 100 parts by mol in a case of the laminated body subjected to dissolution treatment to be made into a solution,
(a) the total content m (parts by mol) of Sr, Ba, and Ca meets 100≦m≦105;
(b) the Si content a (parts by mol) meets 0.1≦a≦4.0;
(c) the Mn content b (parts by mol) meets 0.1≦b≦4.0;
(d) the Al content c (parts by mol) meets 0.01≦c≦3.0;
(e) the V content d (parts by mol) meets 0.01≦d≦0.3;
(f) the molar ratio w (Sr/(Sr+Ba+Ca)) of the total of Sr, Ba, and Ca to Sr meets 0.60≦w≦0.95;
(g) the molar ratio y (Ca/(Sr+Ba+Ca)) of the total of Sr, Ba, and Ca to Ca meets 0≦y≦0.35;
(h) the molar ratio z (Zr/(Zr+Ti)) of the total of Zr and Ti to Zr meets 0.92≦z≦0.98;
the total of the value of the w and the value of the y meets the relationship of 0.6≦w+y≦0.95; and
the plurality of dielectric ceramic layers each have crystal grains; and the crystal grains are 1.2 μm or less in average grain size.
It is to be noted that the phrase “the case of the laminated body subjected to dissolution treatment to be made into a solution” in the present invention refers to a concept that means a case of the laminated body dissolved with an acid to be made into a solution, a case of the laminated body subjected to alkali fusion, and then dissolved in an acid to be made into a solution, etc., and the method for subjecting the laminated body to the dissolution treatment to be made into a solution is not specially restricted.
Furthermore, a laminated ceramic capacitor according to the present invention is:
a laminated ceramic capacitor including:
a laminated body including a plurality of dielectric ceramic layers stacked, and a plurality of internal electrodes provided at more than one interface of the interfaces between the dielectric ceramic layers; and
an external electrode formed on the outer surface of the laminated body and electrically connected to the internal electrodes,
and characterized in that:
the dielectric ceramic layers contain:
Si, Mn, Al, V and a perovskite-type compound containing Sr, Ba, Zr, Ti, and optionally containing Ca,
when the total content of Zr and Ti is regarded as 100 parts by mol,
(a) the total content m (parts by mol) of Sr, Ba, and Ca meets 100≦m≦105;
(b) the Si content a (parts by mol) meets 0.1≦a≦4.0;
(c) the Mn content b (parts by mol) meets 0.1≦b≦4.0;
(d) the Al content c (parts by mol) meets 0.01≦c≦3.0;
(e) the V content d (parts by mol) meets 0.01≦d≦0.3;
(f) the molar ratio w (Sr/(Sr+Ba+Ca)) of the total of Sr, Ba, and Ca to Sr meets 0.60≦w≦0.95;
(g) the molar ratio y (Ca/(Sr+Ba+Ca)) of the total of Sr, Ba, and Ca to Ca meets 0≦y≦0.35;
(h) the molar ratio z (Zr/(Zr+Ti)) of the total of Zr and Ti to Zr meets 0.92≦z≦0.98;
the total of the value of the w and the value of the y meets the relationship of 0.6≦w+y≦0.95; and
the plurality of dielectric ceramic layers each have crystal grains; and the crystal grains are 1.2 μm or less in average grain size.
In the laminated ceramic capacitor according to the present invention, the crystal grains are preferably 1.0 μm or less in average grain size.
The crystal grains adjusted to 1.0 μm or less in average grain size can provide a laminated ceramic capacitor which further has a low initial short circuit ratio, and excellent insulation degradation life and moisture-resistance load life.
Furthermore, the internal electrodes preferably contain Ni or a Ni alloy.
The use of, as the internal electrodes, internal electrodes containing Ni or a Ni alloy makes it possible to provide a highly reliable laminated ceramic capacitor while reducing the material cost.
Furthermore, a method for manufacturing a laminated ceramic capacitor according to the present invention is characterized in that it includes the steps of:
(1) preparing ceramic slurry by mixing a powder including a Si compound, a Mn compound, an Al compound, a V compound, and a perovskite-type compound containing Sr, Ba, Zr, Ti and optionally containing Ca, and making the mixture into slurry, where in the ceramic slurry, when the total content of Zr and Ti is regarded as 100 parts by mol,
a) the total content m (parts by mol) of Sr, Ba, and Ca meets the requirement of 100≦m≦105,
b) the Si content a (parts by mol) meets the requirement of 0.1≦a≦4.0,
c) the Mn content b (parts by mol) meets the requirement of 0.1≦b≦4.0,
d) the Al content c (parts by mol) meets the requirement of 0.01≦c≦3.0,
e) the V content d (parts by mol) meets the requirement of 0.01≦d≦0.3,
f) the molar ratio w (Sr/(Sr+Ba+Ca)) of the total of Sr, Ba, and Ca to Sr meets the requirement of 0.60≦w≦0.95,
g) the molar ratio y (Ca/(Sr+Ba+Ca)) of the total of Sr, Ba, and Ca to Ca meets the requirement of 0≦y≦0.35,
h) the molar ratio z (Zr/(Zr+Ti)) of the total of Zr and Ti to Zr meets the requirement of 0.92≦z≦0.98, and
the total of the value of the w and the value of the y meets the requirement of 0.6≦w+y≦0.95;
(2) forming the ceramic slurry into a sheet shape to obtain ceramic green sheets;
(3) forming an unfired laminated body obtained by stacking the ceramic green sheets and conductor patterns to serve as internal electrodes after being subjected to firing; and
(4) firing the unfired laminated body to obtain a laminated body that has a structure with internal electrodes provided at more than one interface of the interfaces between the plurality of dielectric ceramic layers stacked, and has crystal grains of 1.2 μm or less in average grain size included in the dielectric ceramic layers.
Furthermore, a method for manufacturing a laminated ceramic capacitor according to the present invention is characterized in that it includes the steps of:
(1) preparing ceramic slurry by weighing and mixing a Si compound, a Mn compound, an Al compound, a V compound, and a powder including a perovskite-type compound containing Sr, Ba, Zr, Ti and optionally containing Ca, and making the mixture into slurry, where in the mixture, when the total content of Zr and Ti is regarded as 100 parts by mol,
a) the total content m (parts by mol) of Sr, Ba, and Ca meets the requirement of 100≦m≦105,
b) the Si content a (parts by mol) meets the requirement of 0.1≦a≦4.0,
c) the Mn content b (parts by mol) meets the requirement of 0.1≦b≦4.0,
d) the Al content c (parts by mol) meets the requirement of 0.01≦c≦3.0,
e) the V content d (parts by mol) meets the requirement of 0.01≦d≦0.3,
f) the molar ratio w (Sr/(Sr+Ba+Ca)) of the total of Sr, Ba, and Ca to Sr meets the requirement of 0.60≦w≦0.95,
g) the molar ratio y (Ca/(Sr+Ba+Ca)) of the total of Sr, Ba, and Ca to Ca meets the requirement of 0≦y≦0.35,
h) the molar ratio z (Zr/(Zr+Ti)) of the total of Zr and Ti to Zr meets the requirement of 0.92≦z≦0.98, and
the total of the value of the w and the value of the y meets the requirement of 0.6≦w+y≦0.95;
(2) forming the ceramic slurry into a sheet shape to obtain ceramic green sheets;
(3) forming an unfired laminated body obtained by stacking the ceramic green sheets and conductor patterns to serve as internal electrodes after being subjected to firing; and
(4) firing the unfired laminated body to obtain a laminated body that has a structure with internal electrodes provided at more than one interface of the interfaces between the plurality of dielectric ceramic layers stacked, and has crystal grains of 1.2 μm or less in average grain size included in the dielectric ceramic layers.
Moreover, in the invention of the method for manufacturing a laminated ceramic capacitor according to the present invention, the powder is preferably a powder prepared by calcining and loosening a material containing a Sr compound, a Ba compound, a Ti compound, and a Zr compound, and a powder that has a (202) diffraction peak obtained by powder X-ray diffraction with an integral width of 0.4° or less.
The composition mentioned above makes it possible to reduce the average grain size for the crystal grains to 1.2 μm or less, and makes it possible to keep down the initial short circuit ratio, and to achieve excellent high-temperature load life and moisture-resistance load life, even when the thickness of the dielectric ceramic layer (the thickness of the dielectric ceramic layer sandwiched between the internal electrodes for the formation of capacitance) is adjusted down to 3.0 μm or less.
Furthermore, the integral width is more preferably 0.3° or less.
The integral width adjusted down to 0.3° or less makes it possible to reduce the average grain size for the crystal grains down to 1.0 μm or less, and makes it possible to keep down the initial short circuit ratio, and to achieve excellent high-temperature load life and moisture-resistance load life, even when the thickness of the dielectric ceramic layer (the thickness of the dielectric ceramic layer sandwiched between the internal electrodes for the formation of capacitance) is adjusted down to 1.5 μm or less.
In the laminated ceramic capacitor according to the present invention, the “laminated body” including the plurality of dielectric ceramic layers stacked and the plurality of internal electrodes provided at more than one interface of the interfaces between the dielectric ceramic layers contains:
Si, Mn, Al, V and the perovskite-type compound containing Sr, Ba, Zr, and Ti, and optionally containing Ca, and
when the total content of Zr and Ti is regarded as 100 parts by mol,
(a) the total content m (parts by mol) of Sr, Ba, and Ca meets the condition of 100≦m≦105,
(b) the Si content a (parts by mol) meets the condition of 0.1≦a≦4.0,
(c) the Mn content b (parts by mol) meets the condition of 0.1≦b≦4.0,
(d) the Al content c (parts by mol) meets the condition of 0.01≦c≦3.0,
(e) the V content d (parts by mol) meets the condition of 0.01≦d≦0.3,
(f) the molar ratio w (Sr/(Sr+Ba+Ca)) of the total of Sr, Ba, and Ca to Sr meets the condition of 0.60≦w≦0.95,
(g) the molar ratio y (Ca/(Sr+Ba+Ca)) of the total of Sr, Ba, and Ca to Ca meets the condition of 0≦y≦0.35,
(h) the molar ratio z (Zr/(Zr+Ti)) of the total of Zr and Ti to Zr meets the condition of 0.92≦z≦0.98,
the total of the value of the w and the value of the y meets condition of 0.6≦w+y≦0.95, and
the crystal grains are 1.2 μm or less in average grain size. Thus, a highly reliable laminated ceramic capacitor can be achieved which has a low initial short circuit ratio, and has excellent moisture-resistance load life and high-temperature load life.
More specifically, according to the present invention, even when the thickness of the dielectric ceramic layer is reduced even down to 3.0 μm or less, a laminated ceramic capacitor can be provided which allows the initial short circuit ratio to be kept down, and has excellent high-temperature load life and moisture-resistance load life.
Moreover, also when the “dielectric ceramic layers” constituting the laminated body are brought within the composition range mentioned above, and composed so as to meet the requirement of crystal grains of 1.2 μm or less in average grain size, a highly reliable laminated ceramic capacitor can be achieved which has a low initial short circuit ratio, and has excellent moisture-resistance load life and high-temperature load life.
In addition, the method for manufacturing a laminated ceramic capacitor according to the present invention is adapted to prepare the ceramic slurry that meets the composition requirements as mentioned above, form the unfired laminated body of stacked the ceramic green sheets obtained by shape forming of the ceramic slurry and conductor patterns to serve as internal electrodes after being subjected to firing, and then fire the unfired laminated body to obtain the laminated body that has a structure with internal electrodes provided between the dielectric ceramic layers, and has crystal grains of 1.2 μm or less in average grain size included in the dielectric ceramic layers, and thus laminated ceramic capacitors can be efficiently manufactured that meet the requirements of the present invention as mentioned above.
Alternatively, also in the case of meeting the predetermined composition requirements as mentioned above at the stage of a mixture (weighed material mixture) of weighed materials obtained by weighing the respective raw materials, preparing the ceramic slurry from the weighed material mixture, forming the unfired laminated body of stacked ceramic green sheets obtained by shape forming of the ceramic slurry and conductor patterns to serve as internal electrodes after being subjected to firing, and then firing the unfired laminated body to obtain the laminate body that has a structure with internal electrodes provided between the dielectric ceramic layers, and has crystal grains of 1.2 μm or less in average grain size included in the dielectric ceramic layers, a laminated ceramic capacitor can be efficiently manufactured which meets the above-mentioned requirements of the present invention.
BRIEF EXPLANATION OF THE DRAWINGS
FIG. 1 is a perspective view of a laminated ceramic capacitor according to an embodiment of the present invention.
FIG. 2 is a front cross-sectional view of the laminated ceramic capacitor according to an embodiment of the present invention.
FIG. 3 is a diagram for explaining a method for measuring the thickness of dielectric ceramic layers of the laminated ceramic capacitor according to an embodiment of the present invention.
FIG. 4 is a diagram for explaining a method for measuring the average grain size for crystal grains per dielectric ceramic layer in the laminated ceramic capacitor according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference to an embodiment of the present invention, features of the present invention will be described below in details.
<Preparation of Laminated Ceramic Capacitor>
For the preparation of a laminated ceramic capacitor, first, respective powders of CaCO 3 , SrCO 3 , BaCO 3 , TiO 2 , and ZrO 2 of 99 weight % or more in purity were prepared as materials constituting the dielectric ceramic layers.
Then, the respective powders (main constituent materials) mentioned above were weighed so that the total content of Sr, Ba, and Ca was m parts by mol with respect to 100 parts by mol of the total content of Zr and Ti, the molar ratio Sr/(Sr+Ba+Ca) of Sr to the total of Sr, Ba, and Ca was w, the molar ratio Ca/(Sr+Ba+Ca) of Ca to the total of Sr, Ba, and Ca was y, and the molar ratio Zr/(Zr+Ti) of Zr to the total of Zr and Ti was z, then mixed in a wet way with a ball mill, dried, and then loosened. Tables 1A and 1B show the values of m, w, y, z, and w+y in the respective samples.
This powder was subjected to calcination for 2 h at 1100 to 1300° C. to synthesize a perovskite-type compound containing Sr, Ba, Zr, and Ti, and optionally containing Ca, and then loosened to obtain a powder (main constituent powder) as a main constituent constituting dielectric ceramic layers. It is to be noted that the production method (synthesis method) for this powder (main constituent powder) is not particularly limited, but it is possible to use a solid-phase method, a hydrothermal method, and various other known methods. In addition, the materials are also not particularly limited, but it is possible to use various forms of carbonates, oxides, hydroxides, chlorides, etc. In addition, inevitable impurities such as HfO 2 may be contained.
Then, for this powder (main constituent powder), the integral width of a (202) diffraction peak was measured by XRD. It is to be noted that the integral width is a value obtained in such a way that the area surrounded by the curve representing the peak shape is divided by the height of the peak top. The measurement result of the integral width is shown together in Tables 1A and 1B.
It is to be noted that the average grain size for crystal grains in the dielectric ceramic layers constituting the laminated ceramic capacitor was controlled mainly by the integral width of the main constituent powder in this embodiment.
Next, respective powders of SiO 2 , MnCO 3 , Al 2 O 3 , and V 2 O 5 were prepared as additive materials. These powders were weighed so that the Si content, Mn content, Al content, and V content were a parts by mol, b parts by mol, c parts by mol, and d parts by mol, respectively, with respect to 100 parts by mol of the total content of Zr and Ti in the main constituent powder, and blended with the main constituent powder to obtain a blended product. Then, this blended product was mixed in a wet way with a ball mill, then dried, and loosened into a dielectric raw material powder. Tables 1A and 1B show the values of a, b, c, and d in the respective samples.
It is to be noted that it is also possible to add materials such as CaCO 3 , SrCO 3 , BaCO 3 , TiO 2 , and ZrO 2 for the adjustment of the molar ratios at the stage of adding the additive materials.
In addition, zirconia may be mixed in some cases from materials other than the weighed materials, such as in the case of using YSZ (yttria stabilized zirconia) balls as media in the process of mixing in a wet way, and in such cases, the proportions of the materials blended are adjusted in consideration of the mixed amount so as to provide the compositions in Tables 1A and 1B.
Then, the dielectric raw material powder obtained in the way described above was, with the addition of a polyvinyl butyral-based binder and an organic solvent such as ethanol thereto, mixed in a wet way with a ball mill to prepare ceramic slurry.
The dielectric raw material powder in the ceramic slurry prepared was dissolved with an acid, and subjected to ICP atomic emission spectroscopy analysis to confirm that the powder had almost the same composition as the compositions shown in Tables 1A and 1B.
TABLE 1A
Average Grain Size (μm)
m
a
b
c
d
Thickness of
Thickness of
w
y
z
(parts
(parts
(parts
(parts
(parts
Calcination
Integral
Dielectric
Dielectric
Sample
(Molar
(Molar
(Molar
by
by
by
by
by
Temperature
Width
Ceramic Layer
Ceramic Layer
Number
Ratio)
Ratio)
w + y
Ratio)
mol)
mol)
mol)
mol)
mol)
(° C.)
(°)
of 3.0 μm
of 1.5 μm
1
0.75
0.05
0.80
0.96
102
1.00
1.00
0.80
0.10
1300
0.25
0.65
0.68
2
0.75
0.05
0.80
0.96
103
1.00
1.00
0.80
0.10
1250
0.28
0.80
0.83
3
0.75
0.05
0.80
0.96
102
1.00
1.00
0.80
0.10
1220
0.30
1.00
1.02
4
0.75
0.05
0.80
0.96
102
1.00
1.00
0.80
0.10
1200
0.34
1.05
1.07
5
0.75
0.05
0.80
0.96
102
1.00
1.00
0.80
0.10
1150
0.38
1.10
1.02
6
0.75
0.05
0.80
0.96
102
1.00
1.00
0.80
0.10
1120
0.40
1.20
1.20
7*
0.75
0.05
0.80
0.96
102
1.00
1.00
0.80
0.10
1100
0.42
1.50
1.40
8
0.60
0.20
0.80
0.94
102
1.00
1.00
0.80
0.10
1300
0.25
0.65
0.72
9*
0.97
0.00
0.97
0.96
103
0.50
1.00
0.40
0.20
1250
0.25
0.26
0.25
10
0.95
0.00
0.95
0.92
104
1.00
1.00
0.80
0.10
1300
0.26
0.68
0.62
11
0.60
0.00
0.60
0.96
103
1.00
1.00
0.80
0.10
1300
0.25
0.65
0.59
12*
0.58
0.00
0.58
0.96
103
1.00
0.50
0.40
0.10
1250
0.26
0.30
0.31
13
0.60
0.35
0.95
0.98
102
1.00
1.00
0.80
0.10
1300
0.25
0.65
0.57
14
0.75
0.05
0.80
0.96
100
1.00
1.00
0.80
0.10
1250
0.28
0.96
0.91
15
0.75
0.05
0.80
0.96
103
1.00
1.00
0.80
0.10
1250
0.28
0.90
0.96
16
0.75
0.05
0.80
0.96
101
1.00
1.00
0.40
0.10
1250
0.28
0.83
0.78
17*
0.58
0.37
0.95
0.96
105
1.00
1.00
0.40
0.10
1250
0.28
0.30
0.26
18*
0.63
0.35
0.98
0.96
104
1.00
1.00
0.40
0.10
1250
0.30
0.29
0.33
19*
0.80
0.10
0.90
0.90
104
0.80
0.80
0.60
0.10
1250
0.26
0.30
0.28
20*
0.80
0.10
0.90
1.00
104
0.80
0.80
0.60
0.10
1250
0.26
0.26
0.25
21*
0.60
0.35
0.95
0.96
107
0.20
0.20
0.80
0.10
1250
0.28
0.28
0.26
22*
0.95
0.00
0.95
0.96
98
0.10
0.10
0.01
0.10
1250
0.25
0.26
0.23
TABLE 1B
Average Grain Size (μm)
m
a
b
c
d
Thickness of
Thickness of
w
y
z
(parts
(parts
(parts
(parts
(parts
Calcination
Integral
Dielectric
Dielectric
Sample
(Molar
(Molar
(Molar
by
by
by
by
by
Temperature
Width
Ceramic Layer
Ceramic Layer
Number
Ratio)
Ratio)
w + y
Ratio)
mol)
mol)
mol)
mol)
mol)
(° C.)
(°)
of 3.0 μm
of 1.5 μm
23*
0.75
0.05
0.80
0.96
104
0.00
0.10
0.10
0.10
1250
0.28
0.25
0.26
24*
0.75
0.05
0.80
0.96
104
0.10
0.00
0.10
0.10
1250
0.28
0.28
0.25
25
0.75
0.05
0.80
0.96
102
0.10
0.10
3.00
0.10
1250
0.28
0.80
0.86
26
0.75
0.05
0.80
0.96
102
0.30
0.30
1.50
0.10
1250
0.28
0.82
0.83
27
0.75
0.05
0.80
0.96
102
0.50
0.50
1.00
0.10
1250
0.28
0.72
0.76
28
0.75
0.05
0.80
0.96
102
0.80
0.80
0.80
0.10
1250
0.28
0.75
0.79
29*
0.75
0.05
0.80
0.96
102
1.20
1.00
0.50
0.10
1100
0.42
1.60
1.51
30
0.75
0.05
0.80
0.96
102
1.50
1.20
0.20
0.10
1250
0.28
0.83
0.88
31
0.75
0.05
0.80
0.96
102
2.00
2.00
0.05
0.10
1250
0.28
0.79
0.75
32
0.75
0.05
0.80
0.96
102
4.00
4.00
0.01
0.10
1250
0.28
0.90
0.93
33*
0.75
0.05
0.80
0.96
102
4.20
1.00
0.50
0.20
1250
0.28
1.00
1.02
34*
0.75
0.05
0.80
0.96
102
1.20
4.20
0.50
0.20
1250
0.28
0.60
0.65
35*
0.75
0.05
0.80
0.96
102
0.10
0.20
0.00
0.10
1250
0.28
0.28
0.27
36*
0.75
0.05
0.80
0.96
102
4.00
4.00
3.20
0.10
1250
0.28
1.20
1.15
37*
0.75
0.05
0.80
0.96
102
0.10
0.20
0.01
0.00
1250
0.28
0.28
0.26
38*
0.75
0.05
0.80
0.96
102
1.50
2.00
0.60
0.32
1250
0.28
0.96
1.00
39
0.75
0.05
0.80
0.96
102
1.00
1.00
0.80
0.01
1250
0.28
0.78
0.73
40
0.75
0.05
0.80
0.96
102
1.00
1.00
0.80
0.05
1250
0.28
0.80
0.75
41
0.75
0.05
0.80
0.96
102
1.00
1.00
0.80
0.08
1250
0.28
0.80
0.83
42
0.75
0.05
0.80
0.96
102
1.00
0.40
0.80
0.14
1250
0.28
0.82
0.86
43
0.75
0.05
0.80
0.96
102
1.00
0.30
0.80
0.18
1250
0.28
0.76
0.78
44
0.75
0.05
0.80
0.96
102
1.00
0.10
0.80
0.30
1250
0.28
0.68
0.70
It is to be noted that in Tables 1A and 1B, the samples marked with * are samples that fail to meet the requirements of the present invention, whereas the other samples are samples that meet the requirements of the present invention.
Then, this ceramic slurry was subjected to sheet forming in accordance with a doctor blade method, and cut to obtain rectangular ceramic green sheets of 15 cm×15 cm in planar dimension. Next, a conductive paste containing Ni as a conductive component was printed onto the ceramic green sheets to form conductor patterns (internal electrode patterns) to serve as internal electrodes after being subjected to firing. It is to be noted that a paste containing 100 parts by weight of Ni powder as a metallic powder, 7 parts by weight of ethyl cellulose as an organic vehicle, and terpineol as a solvent was used as the conductive paste in this embodiment.
Then, a plurality of ceramic green sheets with the conductor patterns (internal electrode patterns) formed were stacked so that the conductor patterns were alternately extracted to the opposite sides, thereby providing an unfired laminated body. Then, this unfired laminated body was heated to 250° C. in the atmosphere to remove the binder.
Then, the laminated body subjected to the binder removal was subjected to firing under the conditions of rate of temperature increase: 3.33° C./min; maximum temperature: 1200 to 1300° C.; and oxygen partial pressure (log PO 2 )=−10.0 MPa, to obtain a sintered laminated body.
Next, the sintered laminated body obtained was subjected to barrel polishing to expose the internal electrodes from end surfaces, and a Cu electrode paste for the formation of external electrodes was applied onto the end surfaces of the laminated body with the internal electrodes exposed, dried, and then baked at a maximum temperature of 800° C. in a reducing atmosphere to form external electrodes.
Thereafter, by barrel plating, Ni plated layers were formed on the surface of the external electrodes, and Sn plated layers were further formed on the Ni plated layers. Thus, the laminated ceramic capacitor (sample) was obtained as shown in the perspective view of FIG. 1 and the front cross-sectional view of FIG. 2 .
As shown in FIGS. 1 and 2 , this laminated ceramic capacitor is structured to have the pair of external electrodes (Cu electrodes)) 13 a , 13 b provided so as to be brought into electrical continuity with the internal electrodes 12 alternately exposed at the opposite end surfaces, on the both end surfaces of the laminated body (laminated ceramic element) 10 including the plurality of dielectric ceramic layers 11 stacked, and the plurality of internal electrodes 12 provided at the plurality of interfaces between the dielectric ceramic layers 11 .
It is to be noted that the dimensions of the laminated ceramic capacitor prepared in the way described above were 1.2 mm in width (W), 2.0 mm in length (L), and 0.6 mm in thickness (T), and the dielectric ceramic layer 11 interposed between the internal electrodes was 3.0 μm or 1.5 μm in thickness. In addition, the total number of effective dielectric ceramic layers was 80, excluding the outer layer section.
<In regard to Thickness of Dielectric Ceramic Layer>
(1) Preparation of Sample
Three pieces of samples were prepared for each of the samples (laminated ceramic capacitors) of sample numbers 1 to 44 prepared in the way described above.
(2) Observation of LT Cross Section
1) Polishing
Each sample was held in such a posture as the width (W) direction in a vertical direction, the sample was encased in resin, and the LT surface defined by the length (L) and thickness (T) of the sample was exposed from the resin.
Then, the LT surfaces of the respective samples were polished by a polishing machine, and polished to a depth on the order of ½ in the width (W) directions of the respective samples. Then, in order to eliminate shear drop of the internal electrodes, which is caused by the polishing, the polished surfaces were processed by ion milling after the completion of the polishing.
2) Measurement of Thickness of Dielectric Ceramic Layer
Then, as shown in FIG. 3 , a line (orthogonal line) L orthogonal to the internal electrodes 12 was drawn in a position on the order of ½ of the LT cross section in the L direction. Next, a region of the sample with the internal electrodes 12 stacked was divided into three equal parts in the thickness (T) direction, i.e., three regions of: upper region; central region; and lower region. Then, excluding the outermost dielectric layers and two or more dielectric ceramic layers observed as being joined due to missing internal electrodes, the thicknesses for ten layers of the dielectric ceramic layers on the orthogonal line L were measured in a central portion for each region to obtain the average value (the number of data pieces: 10 layers×3 regions×3 (the number of samples)=90 pieces of data).
It is to be noted that the thickness for the dielectric ceramic layers was measured with the use of a scanning electron microscope.
<Confirmation of Composition of Laminated Body>
For each of the samples (laminated ceramic capacitors) prepared, the laminated body (ceramic sintered body) with the external electrodes removed therefrom was dissolved with an acid, and subjected to ICP atomic emission spectroscopy analysis. As a result, it has been confirmed that the body has almost the same composition as the compositions shown in Tables 1A and 1B, except for Ni as an internal electrode constituent.
<Characteristic Evaluation for Each Sample>
The following evaluations were made for each of samples (laminated ceramic capacitors) prepared in the way described above.
(1) Average Grain Size
Each sample (laminated ceramic capacitor) was fractured so as to expose the WT cross section at a depth on the order of ½ in the length (L) direction of the sample. Next, the sample was subjected to heat treatment in order to define the boundaries (grain boundaries) between crystal grains in the dielectric ceramic layers. The temperature for the heat treatment was adjusted to a temperature for keeping away from grain growth and defining the grain boundaries, and in this embodiment, the treatment was carried out at 1000° C.
Then, as shown in FIG. 4 , a region near the position on the order of ½ in each of the W and T directions (that is, a substantially central region of the fracture section) at the fracture section (WT cross section) of the laminated body 10 , which was fractured in the way described above, was observed as a measurement region ( FIG. 4 ) at 10000-fold magnification with a scanning electron microscope (SEM).
Then, forty crystal grains were extracted in a random manner from the SEM image obtained, and subjected to image analysis to calculate the area of the portion inside the grain boundary for each crystal grain, and calculate the equivalent circle diameter, and the diameter was regarded as the grain size for each crystal grain. This grain size measurement for each crystal grain was made for three pieces of samples of respective conditions (the number of data pieces: 40 crystal grains×3 (the number of samples)=120 pieces of data).
Furthermore, assuming that the shape of each crystal grain was a sphere with, as a diameter, the grain size calculated in the way described above, the volume of each crystal grain was calculated as the volume of the sphere. Then, from the grain size and volume calculated in the way described above, the volume average grain sizes of the samples of respective conditions were calculated, and regarded as the average grain sizes of respective conditions. The thus obtained average grain sizes are shown together in Tables 1A and 1B.
(2) Initial Short Circuit Ratio
For each sample of sample numbers 1 to 44, 100 pieces (n=100) were checked on the initial short circuit ratio. In this case, the sample with the initial value of log IR down to 6 or less was counted as a defective short-circuited sample. The results are shown in Tables 2A and 2B.
(3) Accelerated Moisture-Resistance Load Test (PCBT)
Under the conditions of temperature: 120° C., humidity: 100% RH, atmospheric pressure: 0.122 MPa (1.2 atm), applied voltage: 50 V, the number of samples: 100 (samples without initial short circuit recognized), an accelerated moisture-resistance load test (PCBT) was carried out to count the number of samples with the value of log IR down to 6 or less after a lapse of 250 h. The results are shown together in Tables 2A and 2B.
(4) High-Temperature Load Life
Under the conditions of:
(a) 170° C. and 200 V (200/3 kV/mm in terms of electric field intensity) in the case of thickness of the dielectric ceramic layer (the thickness of the dielectric ceramic layer sandwiched between internal electrodes for the formation of capacitance) of 3.0 μm; and
(b) 150° C. and 100 V (100/1.5 kV/mm in terms of electric field intensity) in the case of thickness of the dielectric ceramic layer of 1.5 μm,
the measurement was made for n=100 (samples without initial short circuit recognized) to count the number of samples with IR below 10 6 Ω after a lapse of 250 h. The results are shown together in Tables 2A and 2B.
It is to be noted that as for the samples with the initial short circuit ratio of 100/100 (the sample of sample number 9 with a thickness of the dielectric ceramic layer of 1.5 μm, the sample of sample number 22 with a thickness of the dielectric ceramic layer of 1.5 μm, the samples of sample number 38 with thicknesses of the dielectric ceramic layer of 3.0 μm and 1.5 μm) in Tables 2A and 2B, meaningful samples for the accelerated moisture-resistance load test and the high-temperature load life test, that is, samples without initial short circuit recognized are unable to be obtained, and thus have not been subjected to the accelerated moisture-resistance load test and the high-temperature load life test.
TABLE 2A
Initial Short Circuit
Moisture-Resistance
High-Temperature
Thickness of
Load Life
Load Life
Dielectric Ceramic
Thickness of Dielectric
Thickness of Dielectric
Sample
Layer
Ceramic Layer
Ceramic Layer
Number
3.0 μm
1.5 μm
3.0 μm
1.5 μm
3.0 μm
1.5 μm
1
0/100
0/100
0/100
0/100
0/100
0/100
2
0/100
0/100
0/100
0/100
0/100
0/100
3
0/100
0/100
0/100
0/100
0/100
0/100
4
0/100
1/100
0/100
0/100
0/100
7/100
5
0/100
2/100
0/100
0/100
0/100
12/100
6
0/100
3/100
0/100
0/100
0/100
13/100
7*
3/100
90/100
22/100
100/100
46/100
98/100
8
0/100
0/100
0/100
0/100
0/100
0/100
9*
90/100
100/100
100/100
—
100/100
—
10
0/100
0/100
0/100
0/100
0/100
0/100
11
0/100
0/100
0/100
0/100
0/100
0/100
12*
93/100
88/100
100/100
100/100
100/100
100/100
13
0/100
0/100
0/100
0/100
0/100
0/100
14
1/100
2/100
0/100
2/100
1/100
2/100
15
0/100
0/100
0/100
0/100
0/100
0/100
16
0/100
0/100
0/100
0/100
0/100
0/100
17*
80/100
85/100
100/100
100/100
100/100
100/100
18*
90/100
90/100
100/100
100/100
100/100
100/100
19*
83/100
88/100
100/100
100/100
100/100
100/100
20*
95/100
96/100
100/100
100/100
100/100
100/100
21*
93/100
90/100
100/100
100/100
100/100
100/100
22*
96/100
100/100
100/100
—
100/100
—
TABLE 2B
Initial Short Circuit
Moisture-Resistance
High-Temperature
Thickness of
Load Life
Load Life
Dielectric Ceramic
Thickness of Dielectric
Thickness of Dielectric
Sample
Layer
Ceramic Layer
Ceramic Layer
Number
3.0 μm
1.5 μm
3.0 μm
1.5 μm
3.0 μm
1.5 μm
23*
60/100
70/100
100/100
100/100
100/100
100/100
24*
65/100
77/100
100/100
100/100
100/100
100/100
25
1/100
1/100
0/100
2/100
1/100
3/100
26
0/100
1/100
0/100
1/100
0/100
0/100
27
0/100
0/100
0/100
0/100
0/100
0/100
28
0/100
0/100
0/100
0/100
0/100
0/100
29*
3/100
83/100
19/100
100/100
45/100
100/100
30
0/100
0/100
0/100
0/100
0/100
0/100
31
0/100
0/100
0/100
0/100
0/100
0/100
32
0/100
1/100
0/100
0/100
0/100
0/100
33*
88/100
92/100
100/100
100/100
100/100
100/100
34*
78/100
96/100
98/100
100/100
100/100
100/100
35*
97/100
96/100
100/100
100/100
100/100
100/100
36*
5/100
90/100
100/100
100/100
93/100
100/100
37*
95/100
90/100
100/100
100/100
100/100
100/100
38*
100/100
100/100
—
—
—
—
39
0/100
0/100
0/100
0/100
0/100
0/100
40
0/100
0/100
0/100
0/100
0/100
0/100
41
0/100
0/100
0/100
0/100
0/100
0/100
42
0/100
0/100
0/100
0/100
0/100
0/100
43
0/100
0/100
0/100
0/100
0/100
0/100
44
0/100
0/100
0/100
0/100
1/100
1/100
It is to be noted that in Tables 2A and 2B, the samples marked with * are samples that fail to meet the requirements of the present invention, whereas the other samples are samples that meet the requirements of the present invention.
As shown in Tables 2A and 2B, it has been confirmed that each of the samples that meet the requirements for the composition specified by the present invention, and meet the requirement (1.2 μm or less) for the average grain size among crystal grains has a low initial short circuit ratio in the case of the thickness of the dielectric ceramic layer of 3.0 μm, and provides a laminated ceramic capacitor which has favorable insulation degradation life and moisture-resistance load life.
In addition, it has been confirmed that the samples that meet the requirements for the composition specified by the present invention, and have an average grain size of 1.0 μm or less for crystal grains have a low initial short circuit ratio even in the case of the thickness of the dielectric ceramic layer adjusted to 1.5 μm, and provide laminated ceramic capacitors which have excellent insulation degradation life and moisture-resistance load life.
In contrast, it has been confirmed that the samples which fail to meet at least one of the requirements for the composition specified by the present invention and the requirement for the average grain size among crystal grains provide unfavorable results for at least any of initial short circuit, moisture-resistance load life, and high-temperature load life.
While the dielectric raw material powder in the ceramic slurry was dissolved with an acid, and subjected to ICP atomic emission spectroscopy analysis, or the laminated body (ceramic sintered body) after removing the external electrodes of the laminated ceramic capacitor (sample) was dissolved with an acid, and subjected to ICP atomic emission spectroscopy analysis in the embodiment described above, it is also possible to carry out a composition analysis for the dielectric ceramic layers constituting the laminated body.
It is to be noted that the present invention is not to be considered limited to the embodiment described above, but various applications and modifications can be made within the scope of the invention in regard to the numbers of the dielectric ceramic layers and internal electrodes constituting the laminated body, the composition of the dielectric ceramic layers, etc.
DESCRIPTION OF REFERENCE SYMBOLS
10 laminated body (laminated ceramic element)
11 dielectric ceramic layer
12 internal electrode
13 a , 13 b external electrode
L length
T thickness
W width | A laminated body that contains a perovskite-type compound containing Sr, Ba, Zr, and Ti and containing; Si; Mn; Al; and V. When the total content of Zr and Ti is 100 parts by mol, the total content m of Sr and Ba meets 100≦m≦105, the Si content a meets 0.1≦a≦4.0, the Mn content b meets 0.1≦b≦4.0, the Al content c meets 0.01≦c≦3.0, the V content d meets 0.01≦d≦0.3, the molar ratio w of Sr and Ba to Sr meets 0.60≦w≦0.95, the molar ratio z of the total of Zr and Ti to Zr meets 0.92≦z≦0.98, w and y meets and the crystal grains are 1.2 μm or less in average grain size. | 2 |
[0001] This application is a continuation-in-part of U.S. Ser. Nos. 08/176,541 and 08/441,252.
FIELD OF THE INVENTION
[0002] The invention relates to a laundry, warewashing, CIP, hard surface, etc. detergent composition that can take the form of a powder, pellet, brick or solid block detergent. Each physical embodiment of the detergent can be packaged in an appropriate packaging system for distribution and sale. Typically, the detergent composition contains a source of alkalinity and an improved surfactant package that substantially improves soil removal and particularly improves soil removal of waxy/fatty soils common-in a number of soil locations.
[0003] The invention also relates to an alkaline warewashing detergent composition in the form of a flake, powder, pellet, block, etc., using a blend of surfactants to enhance cleaning properties. More specifically, the invention relates to an alkaline cleaning system that contains a source of alkalinity, a cooperating blend of surfactants and other cleaning materials that can substantially increase the cleaning capacity, relating to specific fatty or waxy soils. The detergent can also contain a variety of other chemical agents including water softening agents, sanitizers, sequestrants, anti-redeposition agents, defoaming agents, etc. useful in detergent compositions useful in many applications.
BACKGROUND OF THE INVENTION
[0004] Detergent compositions comprising a source of alkalinity, a surfactant or surfactant package combined with other general washing chemicals have been known for many years. Such materials have been used in laundry products, warewashing compositions, CIP cleaners, hard surface cleaners etc. Virtually any cleaner containing a source of alkalinity that is designed or formulated for dilution into an aqueous based composition can be used within this broad general concept. The powder dishwasher detergents are disclosed in, for example, in Dos et al., U.S. Pat. No. 3,956,199, Dos et al., U.S. Pat. No. 3,963,635. Further, Macmullen et al., U.S. Pat. No. 3,032,578 teach alkaline dishwashing detergents containing a chlorine source, an organic phosphonate, a surfactant composition and a water treating agent. Similarly, Almsted et al., U.S. Pat. No. 3,351,557, Davis et al, U.S. Pat. No. 3,341,459, Zimmerman et al., U.S. Pat. Nos. 3,202,714 and 3,281,368 teach built liquid laundry detergent comprising a source of alkalinity and nonionic surfactant materials.
[0005] Powdered general purpose, warewashing and laundry detergents have been used for many years. The manufacture and use of solid block cleaning compositions were pioneered in technology disclosed in Fernholz et al., U.S. Reissue Pat. Nos. 32,763 and 32,818 and in Heile et al., U.S. Pat. Nos. 4,595,520 and 4,680,134. Gansser, U.S. Pat. No. 4,753,441, presents a solid detergent technology in a cast solid form using a nitrilotriacetate sequestrant. The solid block detergents move quickly replaced a large proportion of conventional powder and liquid forms of warewashing detergents and other products in commercial, institutional and industrial laundry, warewashing etc. washing and cleaning markets for safety convenience and other reasons. The development of these solid block cleaning compositions revolutionized the manner in which many cleaning and sanitizing compositions including warewashing detergent compositions are manufactured and used in commercial, institutional and industrial cleaning locations. Solid block compositions offer certain advantages over conventional liquids, powders, granules, pastes, pellets and other forms of detergents. Such advantages include safety, improved economy, improved handling, etc.
[0006] In the manufacture of powdered detergents, powdered ingredients are typically dry blended or agglomerated in known manufacturing facilities to produce a physically and segregation stable powder composition that can be packaged, distributed and sold without substantial changes in product uniformity. Liquid materials are commonly blended in aqueous or nonaqueous solvent materials, diluted with a proportion of water to produce an aqueous based liquid concentrate which is then packaged, distributed and sold. Solid block detergent compositions are commonly manufactured and formed into a solid often using a hardening mechanism.
[0007] In the manufacture of solid detergents, various hardening mechanisms have been used in the manufacture of cleaning and sanitizing compositions for the manufacture of the solid block. Active ingredients have been combined with a hardening agent under conditions that convert the hardening agent from a liquid to a solid rendering the solid material into a mechanically stable block format. One type of such hardening systems is a molten process disclosed in the Fernholz patents. In the Fernholz patents, a sodium hydroxide hydrate, having a melting point of about 55°-60° C., acts as a hardening agent. In the manufacturing process, a molten sodium hydroxide hydrate liquid melt is formed into which is introduced solid particulate materials. A suspension or solution of the solid particulate materials in the molten caustic is formed and is introduced into plastic bottles called capsules, also called container shaped molds for solidification. The material cools, solidifies and is ready for use. The suspended or solubilized materials are evenly dispersed throughout the solid and are dispensed with the caustic cleaner.
[0008] Similarly, in Heile et al., an anhydrous carbonate or an anhydrous sulfate salt is hydrated in the process forming a hydrate, having a melting point about 55° C., that comprises proportions of monohydrate, heptahydrate and decahydrate solid. The carbonate hydrate is used similarly to the caustic hydrate of Fernholz et al to make a solid block multicomponent detergent. Other examples of such molten processes include Morganson, U.S. Pat. No. 4,861,518 which discloses a solid cleaning concentrate formed by heating an ionic and nonionic surfactant system with the hardening agent such as polyethylene glycol, at temperatures that range greater than about 38° C. to form a melt. Such a melt is combined with other ingredients to form a homogeneous dispersion which is then poured into a mold to harden. Morganson et al, U.S. Pat. No. 5,080,819 teaches a highly alkaline cast solid composition adapted for use at low temperature warewashing temperatures using effective cleaning amounts of a nonionic surfactant to enhance soil removal. Gladfelter, U.S. Pat. No. 5,316,688 teaches a solid block alkaline detergent composition wrapped in a water soluble or water dispersible film packaging.
[0009] Solid pelletized materials are shown in Gladfelter, U.S. Pat. Nos. 5,078,301, 5,198,198 and 5,234,615 and in Gansser U.S. Pat. Nos. 4,823,441 and 4,931,202. Such pelletized materials are typically made by extruding a molten liquid or by compressing a powder into a tablet or pellet. Extruded nonmolten alkaline detergent materials are disclosed in Gladfelter et al., U.S. Pat. No. 5,316,688.
[0010] These powdered, pellet, liquid and solid block detergent compositions have acceptable cleaning properties for most commercial purposes. Materials introduced into customer based testing or sold in the market place have achieved commercially acceptable and uniformly passing cleaning results. However, we have found, under certain conditions of fabric, ware, substrate, water hardness, machine type, soil type and load, etc., some stains have resisted removal during the cleaning process. We have found a number of waxy-fatty soils that appear to harden on the surface of ware and resist even highly alkaline cleaning detergents under certain conditions. Such soils are common in the cleaning environment and are typically hydrophobic materials that can form thin films on the surface of a variety of items. We have found that lipsticks soils can act as a soil model for this broad hydrophobic waxy-fatty soil genus. Lipsticks typically contain a large proportion of lipid, fatty and wax-like materials in a relatively complex mixture including waxy compositions, fatty materials, inorganic components, pigments, etc. The wax-like materials typically include waxes such as candelilla wax, paraffin wax, carnuba wax, etc. Fatty ingredients typically include lanolin derivatives, isopropyl isostearate, octyl hydroxy stearate, castor oil, cetyl alcohol, cetyl lactate, and other materials. Such lipid materials are typically difficult to remove under the best of circumstances. More importantly, we believe the castor oil component of lipstick formulations are unsaturated materials that can act like drying oils and can oxidatively crosslink in thin films to form crosslinked or pseudocrosslinked soil layers that are highly resistant to detergents. The formation of lipstick soils and other similar thin film, fatty or waxy, soils resistant to removal has been a stubborn soil requiring attention for many years. Under certain circumstances such waxy-fatty soils can remain on glassware, cups, flatware, dishware, etc.
[0011] A substantial need exists to improve the cleaning properties of solid block detergent materials and particularly as it relates to hydrophobic (fatty, crosslinked fatty or waxy) soils for which lipstick stains are a good model.
[0012] A number of avenues can and have been explored in such an improvement attempt. Examples of research areas can include experimentation in the effects of water temperature, sequestrants that reduce water hardness, the effect of various alkaline sources, the effects of sequestrant types and blends, solvents effects and surfactant choice. The surfactants that can be used in the cast solid materials are vast. There are large numbers of anionic, nonionic, cationic, amphoteric or zwitterionic, etc. surfactants that can be used singly or in combinations of similar or diverse types. Even after substantial experimentation, waxy-fatty soils continue to pose a serious problem.
BRIEF DESCRIPTION OF THE INVENTION
[0013] The invention relates to a detergent composition having a blend of surfactants that substantially enhance cleaning properties of a detergent composition for removal of stubborn hydrophobic soils including waxy-fatty soils for which lipstick stains are a good soil model. The detergent compositions of the invention can be formulated in a variety of product formats including liquid, powder, pellet, solid block, agglomerate powder etc. The detergent composition comprises a source of alkalinity with a first nonionic surfactant and a second nonionic substituted silicone surfactant. The combination of a first nonionic surfactant and a second nonionic silicone surfactant, produces surprisingly effective removal of hydrophobic waxy-fatty soil from the surface of ware. The second nonionic silicone surfactant and the nonionic surfactant cooperate to reduce surface tension to a surprising degree. The surface tension reduction appears to be roughly related to soil removal. The combination of surfactants also appears to affect the interface between the soil and the ceramic or siliceous surface of glassware or tableware.
[0014] For the purpose of this patent application, the term “nonionic surfactant” typically indicates a surfactant having a hydrophobic group and at least one hydrophilic group comprising a (EO) x group wherein x is a number that can range from about 1 to about 100. The combination of a generic hydrophobic group and such a hydrophilic group provides substantial surfactancy to such a composition. The nonionic silicone surfactant is typically a surfactant having a hydrophobic silicone (polydimethyl siloxane) group with at least one pendent hydrophilic group or groups that can comprise (EO) x wherein x is a number of about 1 to about 100 in a surfactant molecule. The first nonionic surfactant can comprise any nonionic surfactant such as a silicone free nonionic surfactant or a nonionic silicone surfactant, however, the second nonionic substituted silicone surfactant cannot comprise a nonionic free of a hydrophobic silicone group.
BRIEF DESCRIPTION OF THE DRAWING
[0015] [0015]FIG. 1 is a drawing of a current embodiment of the solid block detergent of the invention. The solid block having a mass of about 3.0 kilograms is made in an extrusion process in which individual or selected mixed components are introduced serially through material introduction ports into an extruder, the extruded block is formed with a useful profile at the extruder exit die and is divided into useful 3.0 kg blocks after extrusion. Once hardened, the material can be packaged (e.g.) in a shrink wrap that can be removed before use or dissolved during use.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] The detergent composition of the invention combines a source of alkalinity, a first nonionic surfactant and a second nonionic silicone surfactant in an alkaline detergent composition. Optionally, the compositions of the invention can also include a solidifying agent, sequestrants, sanitizing and disinfectant agents, additional surfactants and any variety of other formulatory and application adjuvants. The term detergent composition should be interpreted broadly to include any cleaning, soil conditioning, antimicrobial, soil preparatory, etc. chemical or other liquid, powder, solid, etc. composition which has an alkaline pH and the surfactant blend of the invention in the different physical formats discussed above.
[0017] The first nonionic surfactants useful in the present invention may be solid or liquid. The nonionic surfactant is used in the compositions of the present invention in an amount from about 0.5% to about 50% by weight, preferably from about 1.0% to about 40% by weight, and most preferably from about 2.0% to about 30% by weight.
[0018] Most commonly, nonionic surfactants are compounds produced by the condensation of an ethylene oxide (forming groups that are hydrophilic in nature) with an organic hydrophobic compound which can be aliphatic, alkyl or alkyl aromatic (hydrophobic) in nature. The length of the hydrophilic polyoxyethylene moiety which can be condensed with another particular hydrophobic compound can be readily adjusted, in size or combined with (PO) propylene oxide, other alkylene oxides or other substituents such as benzyl caps to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.
[0019] Examples of suitable types of nonionic surfactant include the polyethylene oxide condensates of alkyl phenols. These compounds include the condensation products of alkyl phenols having an alkyl group containing from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide. Ethylene oxide being present in amounts equal to 5 to 20 moles of ethylene oxide per mole of alkyl phenol. Examples of compounds of this type include nonyl phenol condensed with an average of about 9.5 moles of ethylene oxide per mole of nonyl phenol, dodecyl phenol condensed with about 12 moles of ethylene oxide per mole of phenol, dinonyl phenol condensed with about 15 moles of ethylene oxide per mole of phenol, diisoctylphenol condensed with about 15 moles of ethylene oxide per mole of phenol. Commercially available nonionic surfactants of this type include Igepal CO-610 marketed by the GAF Corporation; and Triton CF-12, X-45, X-114, X-100 and X-102, all marketed by the Rohm and Haas Company.
[0020] The condensation products of aliphatic alcohols with ethylene oxide can also exhibit useful surfactant properties. The alkyl chain of the aliphatic alcohol may either be straight or branched and generally contains from about 3 to about 22 carbon atoms. Preferably, there are from about 3 to about 18 moles of ethylene oxide per mole of alcohol. The polyether can be conventionally end capped with acyl groups including methyl, benzyl, etc. groups. Examples of such ethoxylated alcohols include the condensation product of about 6 moles of ethylene oxide with 1 mole of tridecanol, myristyl alcohol condensed with about 10 moles of ethylene oxide per mole of myristyl alcohol, the condensation product of ethylene oxide with coconut fatty alcohol wherein the coconut alcohol is a mixture of fatty alcohols with alkyl chains varying from 10 to 14 carbon atoms and wherein the condensate contains about 6 moles of ethylene oxide per mole of alcohol, and the condensation product of about 9 moles of ethylene oxide with the above-described coconut alcohol. Examples of commercially available nonionic surfactants of this type include Tergitol 15-S-9 marketed by the Union Carbide Corporation. PLURAFAC® RA-40 marketed by BASF Corp. Neodol 23-6.5 marketed by the Shell Chemical Company and Kyro EOB marketed by the Procter & Gamble Company.
[0021] The condensation products of ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol can be used. The hydrophobic portion of these compounds has a molecular weight of from about 1,500 to 1,800 and of course exhibits water insolubility. The addition of polyoxyethylene moieties to this hydrophobic portion tends to increase the water solubility of the molecule as a whole, and the liquid character of the product is retained up to the point where the polyoxyethylene content is about 50% of the total weight of the condensation product. Examples of compounds of this type include certain of the commercially available Pluronic surfactants marketed by the Wyandotte Chemicals Corporation.
[0022] The condensation products of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine can be used. The hydrophobic base of these products consists of the reaction product of ethylene diamine and excess propylene oxide, said base having a molecular weight of from about 2,500 to about 3,000. This base is condensed with ethylene oxide to the extent that the condensation product contains from about 40 to about 80 percent by weight of polyoxyethylene and has a molecular weight of from about 5,000 to about 11,000. Examples of this type of nonionic surfactant include certain of the commercially available Tetronic compounds marketed by the Wyandotte Chemical Corporation. Mixtures of the above surfactants are also useful in the present invention.
[0023] Preferred nonionic surfactants used herein are the ethoxylated nonionics, both from the standpoint of availability and cleaning performance. Specific examples of alkoxylated nonionic surfactants include, but are not limited to a benzyl ether of a C 6-24 linear alcohol 5-15 mole ethoxylate, PLURAFAC® RA-40, a straight chain alcohol ethoxylate, Triton CF-21 an alkyl aryl polyether, Triton CF-54, a modified polyethoxy adduct, and others.
[0024] The second nonionic can comprise a silicon surfactant of the invention that comprises a modified dialkyl, preferably a dimethyl polysiloxane. The polysiloxane hydrophobic group is modified with one or more pendent hydrophilic polyalkylene oxide group or groups. Such surfactants provide low surface tension, high wetting, antifoaming and excellent stain removal. We have found that the silicone nonionic surfactants of the invention, in a detergent composition with another nonionic surfactant can reduce the surface tension of the aqueous solutions, made by dispensing the detergent with an aqueous spray, to between about 35 and 15 dynes/centimeter, preferably between 30 and 15 dynes/centimeter. The silicone surfactants of the invention comprise a polydialkyl siloxane, preferably a polydimethyl siloxane to which polyether, typically polyethylene oxide, groups have been grafted through a hydrosilation reaction. The process results in an alkyl pendent (AP type) copolymer, in which the polyalkylene oxide groups are attached along the siloxane backbone through a series of hydrolytically stable Si—C bond.
[0025] These nonionic substituted poly dialkyl siloxane products have the following generic formula:
[0026] wherein PE represents a nonionic group, preferably —CH 2 —(CH 2 ) p —O-(EO) m (PO) n -Z, EO representing ethylene oxide, PO representing propylene oxide, x is a number that ranges from about 0 to about 100, y is a number that ranges from about 1 to 100, m, n and p are numbers that range from about 0 to about 50, m+n≧1 and Z represents hydrogen or R wherein each R independently represents a lower (C 1-6 ) straight or branched alkyl.
[0027] Preferred silicone nonionic surfactants have the formula:
[0028] wherein x represent a number that ranges from about 0 to about 100, y represent a number that ranges from about 1 to about 100, a and b represent numbers that independently range from about 0 to about 60, a+b≧1, and each R is independently H or a lower straight or branched (C 1-6 ) alkyl.
[0029] A second class of nonionic silicone surfactants is an alkoxy-end-blocked (AEB type) that are less preferred because the Si—O— bond offers limited resistance to hydrolysis under neutral or slightly alkaline conditions, but breaks down quickly in acidic environments.
[0030] Preferred surfactants are sold under the SILWET® trademark or under the ABIL® B trademark. One preferred surfactant, SILWET® L77, has the formula:
(CH 3 ) 3 Si—O(CH 3 )Si(R 1 )O—Si(CH 3 ) 3
[0031] wherein R 1 =—CH 2 CH 2 CH 2 —O—[CH 2 CH 2 O] z CH 3 ; wherein z is 4 to 16 preferably 4 to 12, most preferably 7-9.
[0032] To provide an alkaline pH, the composition comprises an alkalinity source. Generally, the alkalinity source raises the pH of the composition to at least 10.0 in a 1 wt-% aqueous solutions and preferably to a range of from about 10.5 to 14. Such pH is sufficient for soil removal and sediment breakdown when the chemical is placed in use and further facilitates the rapid dispersion of soils. The general character of the alkalinity source is limited only to those chemical compositions which have a substantial aqueous solubility. Exemplary alkalinity sources include an alkali metal silicate, hydroxide, phosphate, or carbonate.
[0033] The alkalinity source can include an alkali metal hydroxide including sodium hydroxide, potassium hydroxide, lithium hydroxide, etc. Mixtures of these hydroxide species can also be used. Alkaline metal silicates can also act as a source of alkalinity for the detergents of the invention. Useful alkaline metal silicates correspond with the general formula (M 2 O:SiO 2 ) wherein for each mole of M 2 O there is less than one mole of SiO 2 . Preferably for each mole of SiO 2 there is from about 1 to about 100 moles of M 2 O wherein M comprises sodium or potassium. Preferred sources of alkalinity are alkaline metal orthosilicate, alkaline metal metasilicate, and other well known detergent silicate materials.
[0034] The alkalinity source can include an alkali metal carbonate. Alkali metal carbonates which may be used in the invention include sodium carbonate, potassium carbonate, sodium or potassium bicarbonate or sesquicarbonate, among others. Preferred carbonates include sodium and potassium carbonates. These sources of alkalinity can be used the detergents of the invention at concentrations about 5 wt-% to 70 wt-%, preferably from about 15 wt-% to 65 wt-%, and most preferably from about 30 wt-% to 55 wt-%.
[0035] In order to soften or treat water, prevent the formation of precipitates or other salts, the composition of the present invention generally comprises components known as chelating agents, builders or sequestrants. Generally, sequestrants are those molecules capable of complexing or coordinating the metal ions commonly found in service water and thereby preventing the metal ions from interfering with the functioning of detersive components within the composition. The number of covalent bonds capable of being formed by a sequestrant upon a single hardness ion is reflected by labeling the sequestrant as bidentate (2), tridentate (3), tetradendate (4), etc. Any number of sequestrants may be used in accordance with the invention. Representative sequestrants include salts of amino carboxylic acids, phosphonic acid salts, water soluble acrylic polymers, among others.
[0036] Suitable amino carboxylic acid chelating agents include N-hydroxyethyliminodiacetic acid, nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), N-hydroxyethyl-ethylenediaminetriacetic acid (HEDTA), and diethylenetriaminepentaacetic acid (DTPA). When used, these amino carboxylic acids are generally present in concentrations ranging from about 1 wt-% to 50 wt-%, preferably from about 2 wt-% to 45 wt-%, and most preferably from about 3 wt-% to 40 wt-%.
[0037] Other suitable sequestrants include water soluble acrylic polymers used to condition the wash solutions under end use conditions. Such polymers include polyacrylic acid, polymethacrylic acid, acrylic acid-methacrylic acid copolymers, hydrolyzed polyacrylamide, hydrolyzed methacrylamide, hydrolyzed acrylamide-methacrylamide copolymers, hydrolyzed polyacrylonitrile, hydrolyzed polymethacrylonitrile, hydrolyzed acrylonitrile methacrylonitrile copolymers, or mixtures thereof. Water soluble salts or partial salts of these polymers such as their respective alkali metal (for example, sodium or potassium) or ammonium salts can also be used. The weight average molecular weight of the polymers is from about 4000 to about 12,000. Preferred polymers include polyacrylic acid, the partial sodium salts of polyacrylic acid or sodium polyacrylate having an average molecular weight within the range of 4000 to 8000. These acrylic polymers are generally useful in concentrations ranging from about 0.5 wt-% to 20 wt-%, preferably from about 1 to 10, and most preferably from about 1 to 5.
[0038] Also useful as sequestrants are alkali metal phosphates, condensed and cyclic phosphates, phosphonic acids and phosphonic acid salts. Useful phosphates include alkali metal pyrophosphate, an alkali metal polyphosphate such a sodium tripolyphosphate (STPP) available in a variety of particle sizes. Such useful phosphonic acids include, mono, di, tri and tetra-phosphonic acids which can also contain groups capable of forming anions under alkaline conditions such as carboxy, hydroxy, thio and the like. Among these are phosphonic acids having the generic formula motif R 1 N[CH 2 PO 3 H 2 ] 2 or R 2 C(PO 3 H 2 ) 2 OH, wherein R 1 may be -[(lower C 1-6 )alkylene]-N—[CH 2 PO 3 H 2 ] 2 or a third —(CH 2 PO 3 H 2 ) moiety; and wherein R 2 is selected from the group consisting of a lower (C 1 -C 6 ) alkyl. The phosphonic acid may also comprise a low molecular weight phosphonopolycarboxylic acid such as one having about 2-4 carboxylic acid moieties and about 1-3 phosphonic acid groups. Such acids include 1-hydroxyethane-1,1-diphosphonic acid CH 3 C(OH)[PO(OH) 2 ] 2 ; aminotri(methylenephosphonic acid) N[CH 2 PO(OH) 2 ] 3 ; aminotri(methylenephosphonate), sodium salt
[0039] 2-hydroxyethyliminobis(methylenephosphonic acid) HOCH 2 CH 2 N[CH 2 PO(OH) 2 ] 2 ; diethylenetriaminepenta(methylenephosphonic acid) (HO) 2 POCH 2 N[CH 2 CH 2 N[CH 2 PO(OH) 2 ] 2 ] 2 ; diethylenetriaminepenta(methylenephosphonate), sodium salt C 9 H (28-x) N 3 Na x O 15 P 5 (x=7); hexamethylenediamine(tetramethylenephosphonate), potassium salt C 10 H (28-x) N 2 K x O 12 P 4 (x=6); bis(hexamethylene)triamine(pentamethylenephosphonic acid) (HO 2 )POCH 2 N[(CH 2 ) 6 N[CH 2 PO(OH) 2 ] 2 ] 2 ; and phosphorus acid H 3 PO 3 . The preferred phosphonate is aminotrimethylenephosphonic acid or salts thereof combined optionally with diethylenetriaminepenta(methylenephosphonic acid). When used as a sequestrant in the invention, phosphonic acids or salts are present in a concentration ranging from about 0.25 to 25 wt %, preferably from about 1 to 20 wt %, and most preferably from about 1 to 18 wt % based on the solid detergent.
[0040] The invention may also comprise a solidifying agent to create a solid detergent mass from a blend of chemical components. Generally, any agent or combination of agents which provides a requisite degree-of solidification and aqueous solubility may be used with the invention. A solidification agent may be selected from any organic or inorganic compound which imparts a solid character and/or controls the soluble character of the present composition when placed in an aqueous environment. The solidifying agent may provide for controlled dispensing by using solidification agents which have a relative increase in aqueous solubility. For systems which require less aqueous solubility or a slower rate of dissolution an organic nonionic or amide hardening agent may be appropriate. For a higher degree of aqueous solubility, an inorganic solidification agent or a more soluble organic agent such as urea. Compositions which may be used with the present invention to vary hardness and solubility include amides such as stearic monoethanolamide, lauric diethanolamide, and stearic diethanolamide. Nonionic surfactants have also been found to impart varying degrees of hardness and solubility when combined with a coupler such as propylene glycol or polyethylene glycol. Nonionics useful in this invention include nonylphenol ethoxylates, linear alkyl alcohol ethoxylates, ethylene oxide/propylene oxide block copolymers such as the Pluronic™ surfactants commercially available from BASF Wyandotte.
[0041] Nonionic surfactants particularly desirable as hardeners are those which are solid at room temperature and have an inherently reduced aqueous solubility as a result of the combination with the coupling agent.
[0042] Other surfactants which may be used as solidifying agents include anionic surfactants which have high melting points to provide a solid at the temperature of application. Anionic surfactants which have been found most useful include linear alkyl benzene sulfonate surfactants, alcohol sulfates, alcohol ether sulfates, and alpha olefin sulfonates. Generally, linear alkyl benzene sulfonates are preferred for reasons of cost and efficiency.
[0043] Amphoteric or zwitterionic surfactants are also useful in providing detergency, emulsification, wetting and conditioning properties. Representative amphoteric surfactants include N-coco-3-aminopropionic acid and acid salts, N-tallow-3-iminodiproprionate salts. As well as N-lauryl-3-iminodiproprionate disodium salt, N-carboxymethyl-N-cocoalkyl-N-dimethylammonium hydroxide, N-carboxymethyl-N-dimethyl-N-(9-octadecenyl)ammonium hydroxide, (1-carboxyheptadecyl)trimethylammonium hydroxide, (1-carboxyundecyl)trimethylammonium hydroxide, N-cocoamidoethyl-N-hydroxyethylglycine sodium salt, N-hydroxyethyl-N-stearamidoglycine sodium salt, N-hydroxyethyl-N-lauramido-β-alanine sodium salt, N-cocoamido-N-hydroxyethyl-β-alanine sodium salt, as well as mixed alicyclic amines, and their ethoxylated and sulfated sodium salts, 2-alkyl-1-carboxymethyl-l-hydroxyethyl-2-imidazolinium hydroxide sodium salt or free acid wherein the alkyl group may be nonyl, undecyl, or heptadecyl. Also useful are 1,1-bis(carboxymethyl)-2-undecyl-2-imidazolinium hydroxide disodium salt and oleic acid-ethylenediamine condensate, propoxylated and sulfated sodium salt. Amine oxide amphoteric surfactants are also useful. This list is by no means exclusive or limiting.
[0044] Other compositions which may be used as hardening agents with the composition of the invention include urea, also known as carbamide, and starches which have been made water soluble through an acid or alkaline treatment. Also useful are various inorganics which either impart solidifying properties to the present composition and can be processed into pressed tablets for carrying the alkaline agent. Such inorganic agents include calcium carbonate, sodium sulfate, sodium bisulfate, alkali metal phosphates, anhydrous sodium acetate and other known hydratable compounds. We have also found a novel hardening or binding agent for alkaline metal carbonate detergent compositions. We believe the binding agent comprises an amorphous complex of an organic phosphonate compound, sodium carbonate, and water. The proportions of this binding hardening agent is disclosed in copending U.S. Ser. No. _______ which is expressly incorporated by reference herein. This carbonate phosphate water binding agent can be used in conjunction with other hardening agents such as a nonionic, etc.
[0045] The solidifying agents can be used in concentrations which promote solubility and the requisite structural integrity for the given application. Generally, the concentration of solidifying agent ranges from about 5 wt-% to 35 wt, preferably from about 10 wt-% to 25 wt-%, and most preferably from about 15 wt-% to 20 wt-%.
[0046] The detergent composition of the invention may also comprise a bleaching source. Bleaches suitable for use in the detergent composition include any of the well known bleaching agents capable of removing stains from such substrates as dishes, flatware, pots and pans, textiles, countertops, appliances, flooring, etc. without significantly damaging the substrate. These compounds are also capable of providing disinfecting and sanitizing antimicrobial efficacy in certain applications. A nonlimiting list of bleaches include hypochlorites, chlorites, chlorinated phosphates, chloroisocyanates, chloroamines, etc.; and peroxide compounds such as hydrogen peroxide, perborates, percarbonates, etc.
[0047] Preferred bleaches include those bleaches which liberate an active halogen species such as Cl 2 , Br 2 , OCl − , or OBr − under conditions normally encountered in typical cleaning processes. Most preferably, the bleaching agent releases Cl 2 or OCl − . A nonlimiting list of useful chlorine releasing bleaches includes calcium hypochloride, lithium hypochloride, chlorinated trisodium phosphate, sodium dichloroisocyanaurate, chlorinated trisodium phosphate, sodium dichloroisocyanurate, potassium dichloroisocyanurate, pentaisocyanurate, trichloromelamine, sulfondichloro-amide, 1,3-dichloro 5,5-dimethyl hydantoin, N-chlorosuccinimide, N,N′-dichloroazodicarbonimide, N,N′-chloroacetylurea, N,N′-dichlorobiuret, trichlorocyanuric acid and hydrates thereof. Because of their higher activity and higher bleaching efficacies the most preferred bleaching agents are the alkaline metal salts of dichloroisocyanurates and the hydrates thereof. Generally, when present, the actual concentration of bleach source or agent (in wt-% active) may comprise about 0.5 to 20 wt-%, preferably about 1 to 10 wt-%, and most preferably from about 2 to 8 wt-% of the solid detergent composition.
[0048] The composition of the invention may also comprise a defoaming surfactant useful in warewashing compositions. A defoamer is a chemical compound with a hydrophobe-hydrophile balance suitable for reducing the stability of protein foam. The hydrophobicity can be provided by an oleophilic portion of the molecule. For example, an aromatic alkyl or alkyl group, an oxypropylene unit or oxypropylene chain, or other oxyalkylene functional groups other than oxyethylene provide this hydrophobic character. The hydrophilicity can be provided by oxyethylene units, chains, blocks and/or ester groups. For example, organophosphate esters, salt type groups or salt forming groups all provide hydrophilicity within a defoaming agent. Typically, defoamers are nonionic organic surface active polymers having hydrophobic groups, blocks or chains and hydrophilic ester groups, blocks, units or chains. However, anionic, cationic and amphoteric defoamers are also known. Phosphate esters are also suitable for use as defoaming agents. For example, esters of the formula RO—(PO 3 M) n -R wherein n is a number ranging from 1 to about 60, typically less than 10 for cyclic phosphates, M is an alkali metal and R is an organic group or M, with at least one R being an organic group such as an oxyalkylene chain. Suitable defoaming surfactants include ethylene oxide/propylene oxide blocked nonionic surfactants, fluorocarbons and alkylated phosphate esters. When present defoaming agents may be present in a concentration ranging from about 0.1 wt-% to 10 wt-%, preferably from about 0.5 wt-% to 6 wt-% and most preferably from about 1 wt-% to 4 wt-% of the composition.
DETAILED DESCRIPTION OF THE DRAWINGS
[0049] [0049]FIG. 1 is a drawing of a preferred embodiment of the packaged solid block detergent 10 of the invention. The detergent has a unique elliptical profile with a pinched waist. This profile ensures that this block with its particular profile can fit only spray on dispensers that have a correspondingly shaped pinch waisted elliptical profile location for the solid block detergent. We are unaware of any solid block detergent having this shape in the market place. The shape of the solid block ensures that no unsuitable substitute for this material can easily be placed into the dispenser for use in a warewashing machine. In FIG. 1 the overall solid block product 10 is shown having a cast solid block 11 (revealed by the removal of packaging 12 ). The packaging includes a label 13 adhered to the packaging 12 . The film wrapping can easily be removed using a weakened tear line 15 or fracture line or 15 a incorporated in the wrapping.
[0050] The foregoing description of the invention provides an understanding of the individual components that can be used in formulating the solid block detergents of the invention. The following examples illustrate the preferred embodiments of the invention, the aqueous surface tension and waxy soil cleaning properties of the invention and contain a best mode.
[0051] In the manufacture of the detergent, a dry bend powder can be made by blending powdered components into a complete formulation. Liquid ingredients can be pre-adsorbed onto dry components or encapsulated prior to mixing. Agglomerated materials can be made using known techniques and equipment. In manufacture of the solid detergent of the invention, the ingredients are mixed together at high shear to form a substantially homogenous consistency wherein the ingredients are distributed substantially evenly throughout the mass. The mixture is then discharged from the mixing system by casting into a mold or other container, by extruding the mixture, and the like. Preferably, the mixture is cast or extruded into a mold or other packaging system, that can optionally, but preferably, be used as a dispenser for the composition. The temperature of the mixture when discharged from the mixing system is maintained sufficiently low to enable the mixture to be cast or extruded directly into a packaging system without first cooling the mixture. Preferably, the mixture at the point of discharge is at about ambient temperature, about 30-50° C., preferably about 35-45° C. The composition is then allowed to harden to a solid form that may range from a low density, sponge-like, malleable, caulky consistency to a high density, fused solid, concrete-like block.
[0052] In a preferred method according to the invention, the mixing system is a twin-screw extruder which houses two adjacent parallel or counter rotating screws designed to co-rotate and intermesh, the extruder having multiple ingredient inlets, barrel sections and a discharge port through which the mixture is extruded. The extruder may include, for example, one or more feed or conveying sections for receiving and moving the ingredients, a compression section, mixing sections with varying temperature, pressure and shear, a die section to shape the detergent solid, and the like. Suitable twin-screw extruders can be obtained commercially and include for example, Buhler Miag Model No. 62 mm, Buhler Miag, Plymouth, Minn. USA.
[0053] Extrusion conditions such as screw configuration, screw pitch, screw speed, temperature and pressure of the barrel sections, shear, throughput rate of the mixture, water content, die hole diameter, ingredient feed rate, and the like, may be varied as desired in a barrel section to achieve effective processing of ingredients to form a substantially homogeneous liquid or semi-solid mixture in which the ingredients are distributed evenly throughout. To facilitate processing of the mixture within the extruder, it is preferred that the viscosity of the mixture is maintained at about 1,000-1,000,000 cP, more preferably about 5,000-200,000 cP.
[0054] The extruder comprises a high shear screw configuration and screw conditions such as pitch, flight (forward or reverse) and speed effective to achieve high shear processing of the ingredients to a homogenous mixture. Preferably, the screw comprises a series of elements for conveying, mixing, kneading, compressing, discharging, and the like, arranged to mix the ingredients at high shear and convey the mixture through the extruder by the action of the screw within the barrel section. The screw element may be a conveyor-type screw, a paddle design, a metering screw, and the like. A preferred screw speed is about 20-250 rpm, preferably about 40-150 rpm.
[0055] Optionally, heating and cooling devices may be mounted adjacent the extruder to apply or remove heat in order to obtain a desired temperature profile in the extruder. For example, an external source of heat may be applied to one or more barrel sections of the extruder, such as the ingredient inlet section, the final outlet section, and the like, to increase fluidity of the mixture during processing through a section or from one section to another, or at the final barrel section through the discharge port. Preferably, the temperature of the mixture during processing including at the discharge port, is maintained at or below the melting temperature of the ingredients, preferably at about 50-200° C.
[0056] In the extruder, the action of the rotating screw or screws will mix the ingredients and force the mixture through the sections of the extruder with considerable pressure. Pressure may be increased up to about 6,000 psig, preferably between about 5-150 psig, in one or more barrel sections to maintain the mixture at a desired viscosity level or at the die to facilitate discharge of the mixture from the extruder.
[0057] The flow rate of the mixture through the extruder will vary according to the type of machine used. In general, a flow rate is maintained to achieve a residence time of the mixture within the extruder effective to provide substantially complete mixing of the ingredients to a homogenous mixture, and to maintain the mixture at a fluid consistency effective for continuous mixing and eventual extrusion from the mixture without premature hardening.
[0058] When processing of the ingredients is complete, the mixture may be discharged from the extruder through the discharge port, preferably a shaping die for the product outside profile. The pressure may also be increased at the discharge port to facilitate extrusion of the mixture, to alter the appearance of the extrudate, for example, to alter the appearance of the extrudate, for example, to expand it, to make it smoother or grainier in texture as desired, and the like.
[0059] The cast or extruded composition eventually hardens due, at least in part, to cooling and/or the chemical reaction of the ingredients. The solidification process may last from one minute to about 2-3 hours, depending, for example, on the size of the cast or extruded composition, the ingredients of the composition, the temperature of the composition, and other like factors. Preferably, the cast or extruded composition “sets up” or begins to harden to a solid form within about 1 minute to about 2 hours, preferably about 5 minutes to about 1 hour, preferably about 1 minute to about 20 minutes.
[0060] The above specification provides a basis for understanding the broad meets and bounds of the invention.
[0061] The following examples and test data provide an understanding of the specific embodiments of the invention and contain a best mode. These examples are not meant to limit the scope of the invention that has been set forth in the foregoing description. Variation within the concepts of the invention are apparent to those skilled in the art.
EXAMPLE I
[0062] [0062] PROTOTYPE FOR TABLE 1 The following formula: 12.40% Water 2.5% A nonionic comprising a Benzyl capped, linear C 10-14 alcohol 12.4 mole ethoxylate 0.5% ABIL ® B 8852 1.572% Defoamer 4.5% Spray-dried aminotrimethylene phosphonic acid, pentasodium salt 48.528% Dense Ash (anhydrous Na 2 CO 3 ) 30% Sodium tripolyphosphate
[0063] was extruded from an extruder at a temperature of about 55° C. forming a solid block detergent having a mass of about 3.0 kilograms. The extruder had 2 ingredient ports. In the first port, the dry ingredients including the anhydrous sodium carbonate, the ABIL surfactant, sodium tripolyphosphate, the amino triethylene phosphonic acid sequestrants and ⅔ of the nonionic defoamer material were introduced. In port 2 , the liquid ingredients including water, the nonionic, and ⅓ of the nonionic defoamer composition were added. The extruder blended the components into a uniform mass. After exiting the machine the blended mass hardened into a solid block detergent.
EXAMPLE II
[0064] [0064] 3.208% Water 2% A Benzyl capped, linear C 10-14 alcohol 12.4 mole ethoxylate 2% PLURAFAC ® RA-40 0.5% Silicone (SILWET ® L-7602) 1.572% Defoamer 4.390% 2-phosphono-butane 1,2,4- tricarboxylic acid 3.250% NaOH, 50% 43.28% Sodium Carbonate (anhy.) 33.5% Sodium tripolyphosphate 6.3% hydroxy propylcellulose- coated (10%) chlorinated isocyanaurate encapsulate
[0065] Example I was made as a cast solid. Example II and each of the detergents in Table 1 were prepared as a solid block as a prototype by combining the ingredients in the dishwasher without forming a solid. This method simulates the dispensing of a cast solid into the dish machine. The formulation in Example I was used as a basis for the prototypes in Table 1. Example I was repeated as a Prototype I. Prototype II was made by increasing the concentration of the Table 1 listed surfactants. Prototype III was developed by substituting the listed surfactants for the surfactants at the concentration listed in Prototype I, etc. Each test sample was prepared by adding a measured quantity of either the solid block or each individual ingredient to a measured quantity of water in the test wash tank to model a cleaning solution derived from contacting a formulated detergent of the invention with water.
[0066] The soil removal properties of a blend of a first nonionic surfactant and a second nonionic silicone containing surfactant were measured using solid block materials and prototype detergent solutions prepared as shown in Examples I and II. The block detergents and the prototype solutions were used in cleaning ware containing lipstick soil. The test was conducted using the following protocol.
[0067] Test Procedures
[0068] A 10-cycle spot, film, protein, and lipstick removal test was used to compare formulas 1 and 2 and other similar formulae under different test conditions. In this test procedure, clean, clean-lipstick stained and milk-coated, Libbey glasses were washed in an institutional dish machine (a Hobart C-44) together with a lab soil and the test detergent formula. Milk coating were created by dipping clean glasses in whole milk and conditioning the glasses for an hour at 100° F. and 65% RH. The concentrations of each detergent were maintained constant throughout the 10-cycle test.
[0069] The lab soil used is a 50/50 combination of beef stew and hot point soil. The hot point soil is a greasy, hydrophobic soil made of 4 parts Blue Bonnet all vegetable margarine and 1 part Carnation Instant Non-Fat milk powder.
[0070] In the test, the milk-coated, stained glasses are used to test the soil removal ability of the detergent formula, while the initially clean glasses are used to test the anti-redeposition ability of the detergent formula. At the end of the test, the glasses are rated for spots, film, protein, and lipstick removal. The rating scale is from 1 to 5 with 1 being the best and 5 being the worst results.
[0071] The data produced by this experiment is displayed below in Table 1. In the table, surfactants in the detergent formula at particular use concentrations and soil load were tested for surface tension at room temperature and 160° F. and lipstick removal protocols using a one cycle and a two to ten cycle test sequence.
TABLE 1 Correlation of Surface Tension Results to 10-Cycle Warewash Test Results Surface Prototype Surfactants used in Total Tension at Based on Detergent Formula Detergent Surfactant Soil Load, Surface Tension 160° F., Lipstick** Lipstick** Example I from Example II Conc., ppm Conc., ppm ppm at RT, dynes/cm dynes/cm Cycle 2-10 Cycle 1 I 2.5% LF-428 800 24 2000 33.14 26.11 1 1 0.5% Abil B 8852 2.5% LF-428 1000 30 2000 32.60 25.69 1 1 0.5% Abil B 8852 II 2% LF-428 800 36 2000 30.81 30.76* 5 5 2% RA-40 0.5% SILWET ® L-7602 III 2% LF-428 800 36 2000 30.76 29.95 1 1 2% RA-40 0.5% Abil B 8852 IV 2% LF-428 800 36 2000 31.70 30.26 1 1 2% RA-40 0.5% Abil B 8847 V 0.875% FC-170-C 800 17.5 2000 <20 <20 1 1 1.313% SILWET ® L-77 VI 0.5% Tegopren 5840 800 24 2000 30.6 26.5 1 1 2.5% Tegin L-90 VII 2% LF-428 800 41.6 2000 31.8 28.5 2 1 2% RA-40 1.2% MT-70 VIII 1.2% MT-70 800 9.6 2000 27.0 24.0 1 2 IX 2% LF-428 800 41.6 2000 31.0 29.2 1 2.5 2% RA-40 0.6% MT-70 0.6% JAQ Quat X 2% LF-428 800 36 2000 31.36 30.98* 1.3 1 2% RA-40 0.5% SILWET ® L-7210 XI 0.5% Tegopren 5840 800 4 2000 34.5 28.7 2.5 1 XII 0.5% Tegopren 5840 800 24 2000 29.8 26.3 1.3 1.5 2.5% Triton CF-21 XIII 0.5% Tegopren 5840 800 24 2000 31.2 27.1 2.25 1 2.5% Triton CF-54 XIV 2% LF-428 800 36 2000 32.27 30.81* 1.5 4 2% RA-40 0.5% Abil B 8878 XV 3.5% LF-428 1000 35 2000 32.85 32.73 3.75 3.75 XVI 2% LF-428 800 36.7 2000 32.0 30.37 3 3 2% RA-40 0.583% LP-300 XVII 1.75% LF-428 1000 35 2000 31.61 34 5 5 1.75% RA-40 XVIII 2% LF-428 800 36 2000 30.22 29.73* 4 5 2% RA-40 0.5% Abil B 8873
[0072] Descriptions of the Surfactants Used and Their Manufacturers
[0073] LF-428: Benzyl ether of a C 10-14 linear alcohol 12.4 mole ethoxylate (Ecolab); Plurafac RA-40: Modified ethoxylated straight chain alcohol (BASF Corp.); Surfadone LP-300: N-dodecyl pyrrolidone (International Specialty Products); Monawet MT-70: Di-tridecyl sodium sulfosuccinate, 70% (Mona Industries Inc.); JAQ Quat: N-alkyl (3% C 12 , 95% C 14 , 2% C 16 ) dimethyl benzyl ammonium chloride dihydrate (Huntington); Abil B 8852, 8847, 8878, 8873; Tegopren 5840: Polysiloxane polyether copolymers (Goldschmidt Chemical Corporation); Silwet L-7602, L-7210, L-77: Polyalkylene oxide-modified dimethylpolysiloxanes (Union Carbide Corporation); Triton CF-21: Alkylaryl polyether (Union Carbide Corporation); Triton CF-54: Modified polyethoxy adduct (Union Carbide Corporation); Fluorad FC-170-C: Fluorinated alkyl polyoxyethylene ethanols (3M Company) Tegin L-90: Glyceryl monolaurate (Goldschmidt Chemical Corporation)
[0074] Table 1 indicates a rough correlation between a low surface tension and improved waxy soil cleaning properties. We have found that when the surfactant blend achieves a surface tension that measures less than about 30 dynes/cm at 160° F., and that the surfactant blend in an alkaline detergent block can remove lipstick soil with other soils without redeposition in a single cycle.
[0075] The foregoing specification, examples and data provide a sound basis for understanding the technical advantages of the invention. However, since the invention can comprise a variety of embodiments, the invention resides in the claims hereinafter appended. | The invention relates to a highly alkaline or mildly alkaline detergent composition having enhanced cleaning properties. The detergent combines a source of alkalinity and a blend of nonionic surfactants that enhances cleaning waxy-fatty soils. | 2 |
This application is a divisional of U.S. Utility patent application Ser. No. 11/240,726, filed on Sep. 30, 2005, which is currently pending.
FIELD OF THE INVENTION
The present invention relates to an absorbent surface cleaning pad, such as a floor cleaning pad, and to a method for fabricating the surface cleaning pad in such a way as to provide zoned absorbency.
BACKGROUND OF THE INVENTION
Conventional floor mops comprise a handle rotatably connected to a mop head and a disposable absorbent cleaning sheet coupled to the mop head. One side of the disposable absorbent cleaning sheet is placed in direct contact with a surface to be cleaned and the opposing side of the cleaning sheet is coupled to the mop head. The cleaning sheet absorbs and retains fluids, and loosens and traps dirt particles on the cleaning surface.
The cleaning sheet may comprise an absorbent portion that includes superabsorbent polymer (SAP) particles. The SAP particles can escape from the absorbent portion during manufacture, shipment, and normal use conditions. This phenomenon is commonly referred to as particle shake-out. A reduction in the amount or volume of SAP particles within the cleaning sheet hinders the performance and decreases the absorbency rating of the cleaning sheet.
Attempts have been made to overcome this problem in other fields such as the field of baby diapers, adult incontinence products, sanitary napkins and the like. For example, an absorbent structure for such products is disclosed in U.S. Pat. No. 6,562,742, which illustrates a diaper absorbent body with SAP particles placed in discrete locations or zones within the structure. According to the disclosure of U.S. Pat. No. 6,562,742, which is incorporated herein by reference in its entirety, superabsorbent polymer particles are placed in at least one strata of an upper ply in longitudinal discrete lanes along the length of the core, and the lanes are separated by adjacent lanes including fibers and a binder. Such a discrete placement of SAP particles is disclosed to allow for better containment of the particles, facilitate flow of liquid in the Z-direction because of the presence of areas with little or no SAP, and allow for easier flow and wicking of the fluid along the length of the core (x-direction). The areas with little or no SAP particles may be additionally densified to improve integrity and create higher capillary tension within smaller pores.
Nevertheless, there continues to be a need for an improved absorbent cleaning pad, such as a floor cleaning pad, and an improved method for fabricating the cleaning pad in such a way as to provide zoned absorbency.
SUMMARY OF THE INVENTION
According to one aspect of the invention, a surface cleaning pad is provided having a pad body with a cleansing surface configured for contact with a surface to be cleaned and an opposed surface configured to be coupled to a cleaning implement. The cleansing surface and the opposed surface together define a thickness of the pad body. The surface cleaning pad also has superabsorbent polymer particles maintained within a zone of the pad body. The zone of the pad body occupies the thickness of the pad body and an area that is contiguous yet less than that of the cleansing surface.
According to another aspect of the invention, a method is provided for forming a surface cleaning pad body having a matrix web of binder fibers and superabsorbent polymer particles. The method includes depositing a mass of binder fibers onto a conveyor. All but a selected area of the mass of binder fibers is shielded, and superabsorbent polymer particles are deposited onto the selected area of the mass of binder fibers so as to disburse superabsorbent polymer particles throughout a thickness of the mass of binder fibers. The mass of binder fibers is formed into a web structure that substantially contains the superabsorbent polymer particles, thereby providing a cleaning pad body with superabsorbent polymer particles substantially contained in a zone of the mass of binder fibers that occupies the thickness of the mass of binder fibers and the selected area. An attachment device is applied to the cleaning pad body, thereby configuring the pad body for attachment to a cleaning implement.
According to yet another aspect of the invention, a method is provided for forming cleaning pad bodies. The method includes forming a substrate of fibers. Superabsorbent polymer particles are applied to the substrate in zones extending along the substrate separated by a gap extending along the substrate. The substrate is parted along the gap to form substrate portions each having an edge portion substantially devoid of superabsorbent polymer particles. The substrate is parted substantially perpendicular to the gap to form cleaning pad bodies.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention will be described with reference to the drawings, of which:
FIG. 1 is a bottom view of an absorbent cleaning pad in accordance with an exemplary embodiment of the present invention;
FIG. 2 is a right side view of the absorbent cleaning pad illustrated in FIG. 1 ;
FIG. 3 is an end view of the absorbent cleaning pad illustrated in FIG. 1 ;
FIG. 4 is a top view of the absorbent cleaning pad illustrated in FIG. 1 , including a cut-away portion of the cleaning pad;
FIG. 5 a is a bottom view of an absorbent cleaning pad in accordance with another exemplary embodiment of the present invention;
FIG. 5 b is a bottom view of an absorbent cleaning pad in accordance with yet another exemplary embodiment of the present invention;
FIG. 5 c is a bottom view of an absorbent cleaning pad in accordance with still another exemplary embodiment of the present invention;
FIG. 6 is a schematic, perspective view of a system that can be used to form an absorbent cleaning pad according to an embodiment of this invention;
FIG. 7 is a schematic, sectional side view of the system illustrated in FIG. 6 ; and
FIG. 8 is a flow chart illustrating exemplary steps of a process for forming an absorbent cleaning pad according to another exemplary embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention. Also, the embodiments selected for illustration in the figures are not shown to scale and are not limited to the proportions shown.
As used herein, the term “superabsorbent polymer (SAP) particle” refers to any absorbent material having a g/g capacity for water of at least about 20 g/g, when measured under a confining pressure of 0.3 psi. Non-limiting examples of suitable superabsorbent materials include water insoluble, water-swellable superabsorbent gelling polymers which are described in U.S. application Ser. No. 09/831,480, the disclosure of which is incorporated herein by reference in its entirety.
Referring to the overall structure of one exemplary embodiment, FIGS. 1-4 illustrate an absorbent cleaning pad designated generally by the numeral “ 110 ”. Generally, the absorbent cleaning pad 110 has a pad body formed from an airlaid composite and having a cleansing surface configured for cleansing contact with a surface to be cleaned and an opposite surface configured to be positioned facing, or attached to, a cleaning implement. The surface cleaning pad also has a barrier adhered to and substantially covering the opposite surface of the pad body and a pair of scrubbing members adhered to the cleansing surface of the pad body.
More specifically, the exemplary absorbent cleaning pad (or sheet) 110 is provided with an airlaid composite 120 . Two folded dirt entrapment members 125 are adhered to a cleaning side 152 of the airlaid composite 120 by an adhesive 130 and extend along the length of the airlaid composite 120 . A barrier layer 140 is adhered to an opposing attachment side 155 of the airlaid composite 120 and is folded around the width-wise sides 124 of the airlaid composite 120 , thereby enclosing the width-wise sides 124 of the airlaid composite 120 . Two attachment members 145 are adhered to the barrier layer 140 by an adhesive 130 .
The airlaid composite 120 of the exemplary embodiment absorbs and retains fluids and/or other matter residing on a cleaning surface. The cleaning side 152 of the cleaning pad 110 is in direct contact with the floor surface, and the opposing attachment side 155 of the absorbent cleaning pad 110 is in contact with a cleaning implement such as a mop head (not shown). The dirt entrapment members 125 serve to facilitate the removal of soils from the surface being cleaned by contacting and trapping larger soil particles. The barrier layer 140 substantially prevents fluid from passing from the airlaid composite 120 to the cleaning implement, to keep the cleaning implement substantially free of fluid. The barrier layer 140 also substantially prevents absorbent particles within the airlaid composite 120 from escaping out of the exposed width-wise sides 124 of the airlaid composite 120 .
The attachment members 145 provide a single attachment mechanism that can be used to temporarily couple the absorbent cleaning pad 110 to a cleaning implement such as a mop head. In this exemplary embodiment, the attachment members 145 are composed of loop fastening material available from Velcro USA Inc. of Manchester, N.H., USA. Additional benefits and features of attachment mechanisms are disclosed in U.S. application Ser. No. 11/241,138. The disclosure of U.S. application Ser. No. 11/241,138 is incorporated herein by reference in its entirety. Also, benefits and features of additional optional components, such as cuff components, are disclosed in U.S. application Ser. No. 11/240,949 and U.S. application Ser. No. 11/241,437, which are incorporated herein by reference in their entirety.
The exemplary embodiment of the absorbent cleaning pad 110 comprises a unitized airlaid composite 120 having an absorbent core composed of at least binder fibers, absorbent fibers and superabsorbent polymer (SAP) particles 150 . The absorbent core should be of sufficient integrity to ensure that the absorbent core does not deform and exhibit discontinuities during its normal use in cleansing a surface. The SAP particles 150 provide the airlaid composite 120 with increased absorbency, while the binder and absorbent fibers form the overall structure of the airlaid composite 120 . In this embodiment, the binder fibers are optionally bi-component fibers and the absorbent fibers are optionally cellulosic fibers.
The absorbency portion of the airlaid composite 120 may optionally be composed of pulp fibers, rayon fibers, superabsorbent fibers, a combination of superabsorbent and pulp fibers, a combination of superabsorbent and rayon fibers, a combination of pulp, superabsorbent and rayon fibers, a non-woven web and a in-situ (liquid) superabsorbent, a tissue and in-situ (liquid) superabsorbent, a pulp and in-situ (liquid) superabsorbent, rayon fibers and a in-situ (liquid) superabsorbent, pulp, rayon fibers and a in-situ (liquid) superabsorbent, or a combination thereof of any of the above. The absorbent core component is an essentially hydrophilic material capable of absorbing and retaining fluids. The absorbent component may be composed of fibers, powders, and polymeric binders, any of which may be natural or synthetic.
The exposed sides of the airlaid composite 120 may be sealed or covered to substantially limit the SAP particles 150 from escaping out of the exposed sides of the airlaid composite 120 . According to exemplary embodiments of this invention, however, to prevent the escapement of the SAP particles 150 , the SAP particles may be concentrated or zoned an adequate distance away from one or more of the exposed sides of the airlaid composite 120 . The matrix web of binder fibers would substantially inhibit the zoned SAP particles from migrating a significant distance toward the exposed sides of the airlaid composite 120 . An example of a zoned SAP region is illustrated in FIG. 1 .
Additional benefits and features of an airlaid composite construction are disclosed in U.S. application Ser. No. 11/240,929. The disclosure of U.S. application Ser. No. 11/240,929 is incorporated herein by reference in its entirety.
In addition to airlaid composites, other absorbent pad body materials, structures and/or processes are contemplated as well. For example, in another exemplary embodiment an absorbent core prepared by expanding a polymer tow, disclosed in International Publication No. WO 2004/017883, is also contemplated for use as an absorbent pad. The disclosure of International Publication No. WO 2004/017883 is incorporated herein by reference in its entirety. In this exemplary embodiment, the absorbent core comprises a plurality of filaments in the form of an expanded tow, and a layer comprising a liquid superabsorbent material on surfaces of the filaments. The liquid superabsorbent polymer may be applied to the expanded tow, for example, by spraying or by application using a gravure roller. In this embodiment, the liquid superabsorbent polymer is applied to a portion(s) of the width and/or the length of the expanded tow.
Referring now to FIGS. 1-4 , specifically FIG. 1 , the SAP particles 150 are dispersed in a discrete zone of the airlaid composite 120 . The SAP particles 150 are substantially concentrated in the center of the width of the airlaid composite 120 to substantially limit the SAP from escaping out of the open length-wise sides 123 of the airlaid composite 120 . The discrete SAP zone 150 comprises the width “C”, the length “B” and the thickness of the airlaid composite 120 . Although the SAP particle 150 zone is contiguous with the exposed width-wise sides 124 of the airlaid composite, the portion of the barrier layer folded over the width-wise sides 124 substantially prevents the escapement of SAP 150 out of the exposed width-wise sides 124 .
The SAP particles 150 are also substantially prevented from escaping through the cleaning side 152 and the attachment side 155 of the airlaid composite. The dense web of binder fibers at the cleaning side 152 and the attachment side 155 of the airlaid composite substantially prevents the SAP particles 150 from escaping. In addition, the barrier layer 140 substantially prevents the SAP particles 150 from escaping out of the attachment side 155 of the airlaid composite 120 , as illustrated in FIG. 4 .
The exemplary embodiment provides several advantages. The zoned SAP particles reduce particle shake out, gel blocking, and manufacturing costs and promote efficient fluid absorption throughout the airlaid composite. SAP particle shake-out hinders the performance of the cleaning pad and degrades the cleaning pad's absorbency rating. By virtue of the zoned SAP, the exemplary cleaning pad 110 can retain a greater number of SAP particles within the airlaid composite.
The discrete placement of SAP particles also facilitates the flow of fluid along the regions of the cleaning pad devoid of SAP particles. The regions without SAP particles promote flow and wicking of fluid along the entire length and width of the exemplary airlaid composite. Therefore, the discrete placement of SAP particles promotes the utilization of the entire airlaid composite for absorption.
The discrete placement of SAP particles also substantially reduces gel blocking within the airlaid composite, thereby improving the cleaning pad's ability to absorb and retain fluid. Gel blocking leads to the inhibition of fluid flow throughout the entire airlaid composite, thereby reducing the absorbency rating of the cleaning pad. In other words, the airlaid composite cannot efficiently absorb fluid if too many SAP particles are positioned or concentrated on the cleaning surface of the airlaid composite, as the swelled SAP particles prevent the fluid from traveling in the z-direction (i.e., along the thickness of the airlaid composite). The discrete placement of SAP particles promotes uniform fluid absorption throughout the exemplary airlaid composite.
From the manufacturing perspective, by virtue of the SAP zone 150 illustrated in FIGS. 1-4 , the barrier layer 140 does not have to be folded over the length-wise sides 123 of the airlaid composite 120 , as there is no need to prevent SAP particles 150 from escaping out of the length-wise sides 123 . The cleaning pad 110 therefore utilizes less barrier layer material and does not require the additional operation of folding the barrier layer over the length-wise sides 123 of the airlaid composite 120 . This represents a cost savings to the manufacturer by way of reduced barrier layer material expense and labor or equipment expense.
Another exemplary embodiment of a cleaning pad 510 is illustrated in is FIG. 5 a . The SAP particle zone 550 is provided in a central region of the airlaid composite 520 , remote from the entire periphery of the airlaid composite 520 . The SAP particle zone 550 may adopt any form, e.g. square as shown, circular, rectangular, semicircular, etc. The outline of the airlaid composite 520 is shown in dotted line form to indicate that the airlaid composite 520 has no boundaries and that the zone 550 can be provided in any desired shape or configuration. In other words, the length and width of the airlaid composite may be any dimension larger than the length “D” and width “E” of the superabsorbent particle 550 zone. For example, the airlaid composite 520 of the exemplary embodiment may be an individual cleaning pad or a continuous cleaning sheet composed of a plurality of cleaning pads.
By virtue of the zoned SAP 550 , the barrier layer (not shown) of the exemplary embodiment illustrated in FIG. 5 a does not have to conceal or otherwise cover the exposed length-wise and width-wise sides of the airlaid composite 520 to prevent shake-out of SAP. The zoned SAP particles 550 cannot migrate to the periphery of the airlaid composite, assuming that there is an adequate gap between the SAP particle zone 550 and the periphery of the airlaid composite 520 . By zoning the SAP particles away from the periphery of the airlaid composite 520 , a material and assembly cost reduction may be realized, as additional barrier layer material does not have to cover the sides of the airlaid composite 520 and the barrier layer folding operations are eliminated.
Another exemplary embodiment of a cleaning pad 510 is illustrated in FIG. 5 b . Similar to the exemplary embodiment illustrated in FIG. 1 , the SAP particle zone 550 extends along the entire length of the airlaid composite 520 . The width-wise sides of the airlaid composite 520 are shown in dotted form to indicate that the length of the airlaid composite 520 is optionally continuous. This exemplary embodiment may optionally represent a continuous airlaid sheet that can be divided, by width-wise cutting or other parting operation, into a plurality of individual airlaid pads.
Another exemplary embodiment of a cleaning pad 510 is illustrated in FIG. 5 c . Similar to the exemplary embodiment illustrated in FIG. 5 b , the SAP zone 550 extends along the entire length of the airlaid composite 520 . This exemplary embodiment provides multiple zones of SAP particle 550 of width “G”. However, the width of the multiple zones of SAP may vary as well, depending upon the fluid distribution and fluid management. The discrete placement of the SAP particle zones 550 facilitates the flow of fluid along the regions of the cleaning pad devoid of SAP particles. The regions without SAP particles promote flow and wicking of the fluid along the length and width of the cleaning pad and limit gel blocking.
Alternatively, the cleaning pad embodiment shown in FIG. 5 c is provided as an interim substrate or step in forming an absorbent cleaning pad. For example, a method of forming cleaning pad bodies can include forming a substrate of fibers, and then depositing superabsorbent polymer particles to the substrate in zones extending along the substrate separated by one or more gaps extending along the substrate to form the interim cleaning pad substrate 510 . The substrate 510 can then be cut or otherwise parted along one or more of the gaps to form substrate portions each having an edge portion substantially devoid of superabsorbent polymer particles. Such an interim substrate 510 can then be parted in a direction substantially perpendicular to the gaps to form cleaning pad bodies. In other words, the substrate 510 can be divided along the gaps between adjacent zones and then cut or parted in a direction substantially perpendicular to the gaps to form shorter lengths, thereby forming a structure corresponding to the absorbent composite 120 used in the absorbent cleaning pad 110 shown in FIGS. 1-4 .
FIGS. 6 and 7 schematically show an example of an airlaid composite forming system 600 that can be used to form an absorbent cleaning pad according to one aspect of the invention if the pad includes an airlaid composite. It is also contemplated that the absorbent cleaning pad is formed with an alternative structure, including any fibrous or non-fibrous material capable of defining a substrate.
Although only one example of an airlaid composite forming system is illustrated, this invention is not limited to the particular airlaid composite forming system selected for illustration in the Figures, and this invention is not limited to an absorbent pad having an airlaid structure. Other airlaid forming systems and other pad-producing processes are contemplated as well.
The airlaid composite forming system 600 comprises a moving perforated forming wire 602 , which acts as a conveyor, with forming head equipment mounted thereabove. In the orientation illustrated in FIGS. 6 and 7 , the upper surface of the wire 602 moves from right to left at a rate appropriate for proper distribution of materials on the wire 602 . Alternatively, the wire 602 can remain stationary while other equipment (e.g., forming heads) move respect to the wire 602 . Nevertheless, a continuous conveyer process such as that illustrated in FIGS. 6 and 7 is advantageous.
Forming heads 604 and 606 each receives a flow of an air fluidized fiber material (e.g., binder fibers, wood pulp, other fibrous materials, or combination thereof) via supply channels 608 . A suction source 614 mounted beneath the perforated moving wire 602 , draws air downwardly through the perforated moving wire 602 . In one embodiment, the binder fiber material is distributed and compacted (by the air flow) over the width of the wire 602 to form an light web layer on the surface of the wire 602 . A second forming head (not shown) is provided to distribute a second web layer 616 composed of a mixture of binder fibers and cellulosic fibers onto the light web layer.
The SAP particles are introduced into the particle dispenser 620 through a tube 618 . The particle dispenser 620 is configured to direct (e.g., spray, sprinkle, release, etc.) the SAP particles onto the perforated moving wire 602 above the web layer 616 . The SAP particles are either distributed over a portion of the width and/or length of the web layer 616 or distributed over the entire web layer 616 . The SAP particles blend and disseminate through the web layer 616 and are thereby maintained throughout the entire thickness of the airlaid composite.
A third forming head 606 is provided to distribute another web layer 622 of binder and/or cellulosic fibers over the SAP particles. Although only two forming heads are illustrated, more forming heads may be required to distribute additional layers of binder fiber or cellulosic fiber. Thereafter, the web layers are heated for a period of time until the binder fibers melt together to form a web-like structure, i.e., an airlaid composite.
In functional terms, the first light web layer including binder fibers is oriented toward the cleaning surface and provides structure to the airlaid composite. The second web layer 616 including binder fibers and cellulosic fibers is maintained over the first light web layer and provides structure and absorbency to the airlaid composite. The SAP particles are maintained over the second web layer 616 to provide additional absorbency to the airlaid composite. The third web layer 622 including binder fibers and cellulosic fibers are maintained over the SAP particles and is oriented toward the cleaning implement. The third web layer 622 provides structure and absorbency to the airlaid composite. The web layers collectively form an airlaid composite according to one embodiment.
Although not shown, in yet another exemplary embodiment, a preformed sheet comprising SAP particles may be positioned above the light web layer 616 , as an alternative to using the particle dispenser 620 . The preformed sheet may be of any size equal to or smaller than the light web layer 616 .
Still referring to the airlaid composite forming system illustrated in FIGS. 6 and 7 , to form the airlaid composite illustrated in FIG. 5 a , the SAP particles are distributed above a portion of the length and the width of the web layer 616 . The particle dispenser 620 is configured to distribute a volume of SAP particles to a zone of length “D” and width “E” above the web layer 616 to form a single airlaid composite. To form a continuous sheet composed of multiple airlaid composites 520 , the particle dispenser 620 is configured to periodically distribute the SAP in zones onto the moving web layer 616 . A processing unit (not shown) controls the operation of the particle dispenser 620 and the duration of each SAP distribution period. The duration of each SAP distribution period is dependent upon the speed of the moving wire 602 , the length of each individual airlaid composite and the length of the SAP particle zone.
In still another exemplary embodiment and still referring to FIGS. 5 a , 6 , and 7 , SAP particles and binder fibers are both introduced into tube 618 of the particle dispenser 620 . The particle dispenser 620 therefore distributes both SAP particles and binder fibers over a zone of length “D” and width “E” over the web layer 616 . However, it should be understood that the particle dispenser 620 and the forming heads 604 and 606 can distribute any type of fiber or particle or combination thereof, as the dispenser and forming heads are not limited to merely distributing binder fibers and SAP particles.
Still referring to the airlaid composite forming system illustrated in FIGS. 6 and 7 , to form the cleaning pad 520 illustrated in FIG. 5 b the SAP particles 550 are distributed above a segment “F” (as illustrated in FIG. 5 b ) of the web layer 616 . The particle dispenser 620 is configured to limit the distribution of the SAP particles 550 over a segment “F” of the web layer 616 . In other words, the particle dispenser 620 only sprays, sprinkles, or releases the SAP particles 550 in segment “F”.
As an alternative to configuring the particle dispenser 620 to distribute the SAP particles over the segment “F” of the web layer 616 , a screen may be positioned above the web layer 616 to limit the placement of the SAP particle zone 550 to a segment “F” of the web layer 616 . In this exemplary embodiment, the particle dispenser 620 is configured to distribute the SAP particles over the entire web layer 616 , although the screen limits the distribution of the SAP particles to the segment “F” above the web layer 616 .
FIG. 8 is a flow chart 800 of exemplary steps for fabricating an airlaid composite in accordance with the present invention. Block 802 illustrates the step of depositing binder fibers onto a moving perforated wire so as to define a cleaning surface of the pad body. Block 803 illustrates the step of depositing both binder and cellulosic fibers above the binder fibers. Block 804 illustrates the step of depositing superabsorbent polymer particles above the binder and cellulosic fibers, wherein an area of the superabsorbent polymer particles is less than an area of binder and cellulosic fibers. Block 808 illustrates the optional step of depositing additional binder fibers above the layer of binder and cellulosic fibers. Block 806 illustrates the final step of bonding the binder fibers with the cellulosic fibers and superabsorbent polymer particles to form a web-like airlaid structure.
While preferred embodiments of the invention have been shown and described herein, it will be understood that such embodiments are provided by way of example only. Numerous variations, changes and substitutions will occur to those skilled in the art without departing from the spirit of the invention. Accordingly, it is intended that the appended claims cover all such variations as fall within the spirit and scope of the invention. Also, the embodiments selected for illustration in the figures are not shown to scale and are not limited to the proportions shown. | A method of forming a surface cleaning pad body comprising a matrix web of binder fibers and superabsorbent polymer particles is provided. The method comprises the steps of depositing a mass of binder fibers onto a conveyor, shielding all but a selected area of the mass of binder fibers, depositing superabsorbent polymer particles onto the selected area of the mass of binder fibers so as to disburse superabsorbent polymer particles throughout a thickness of the mass of binder fibers, and bonding the mass of binder fibers to form a web structure and to substantially contain the superabsorbent polymer particles, thereby providing a cleaning pad body with superabsorbent polymer particles substantially contained in a zone of the mass of binder fibers that occupies at least a portion of the thickness of the mass of binder fibers and the selected area. The method further comprises the step of applying an attachment device to the cleaning pad body, thereby configuring the pad body for attachment to a cleaning implement. | 3 |
TECHANICAL FIELD
This invention is in the field of telephone line equipment, and more particularly, telephone line equipment that can detect valid ringing signals and pass them on to other equipment.
BACKGROUND OF THE INVENTION
In the telephone art, several different electrical signals are transmitted over the pair of wires that connects each telephone instrument to the central office. In addition to the audio voice signal, there is the off-hook signal which indicates that the telephone instrument is in use, the dialing signal which transmits the telephone number dialed, and the ringing signal which causes an alerting device to operate. Since the original alerting devices were bells, that signal is known as a ringing signal. In order to distinguish it from the various other signals, the ringing signal is a high voltage alternating current signal with a frequency of approximately 20 Hz. Various circuits have been devised which reliably distinguish valid ringing signals from among the other signals and the many types of noise that can exist on a telephone line. A relatively recent development, however, is what is known as distinctive ringing in which short bursts of ringing signal are applied to the alerting device to indicate the source of the call. For example, ringing in single bursts might indicate that a call has originated from a long distance line, while groups of two bursts may indicate that the call has originated within the local system. This distinctive ringing has been available within the confines of a private branch exchange (PBX) which serves a single location. Because the pre-existing ringing detectors could not reliably detect these distinctive ringing signals, a new detector was devised which operated very well within the confines of a PBX system. U.S. Pat. No. 4,491,691 which issued to Embree et al. on Jan. 1, 1985 describes such a ringing detecting system.
According to the Embree et al. distinctive ringing detector, a digital magnitude comparator produces a binary output indicative of whether the tip-ring voltage, that is, the telephone line voltage, exceeds a predetermined magnitude. The integrator generates a time integral of the digital output; when the time integral exceeds a predetermined value, ringing is indicated.
Because of the success of the distinctive ringing feature with PBX's, a demand has arisen to provide the same service with off premise stations. Unfortunately, the environment for off-premise telephone plant is much harsher, rendering even the Embree ringer unsatisfactory for this purpose. The inductance associated with long lines together with much greater interference pickup make both dial pulses and interferences such as switching transients and lightning resemble much more closely the short bursts of distinctive ringing. In addition, the Embree circuit requires a power dissipating bridge which lowers the tip-ring impedance to an undesirable level.
Our invention provides much more accurate detection of ringing signals in the off-premise environment and eliminates the need for a low impedance power dissipating bridge.
SUMMARY OF THE INVENTION
A magnitude comparator coupled to the input signal produces a binary signal indicative of whether the instantaneous magnitude of the input signal exceeds a predetermined magnitude. An integrator produces a time integral of the binary signal, and a timer controls the interval of time over which the binary signal is integrated. Integral comparison means responsive to the integrator indicates the presence of a valid ringing signal if, at the end of the integrating interval the integral exceeds a predetermined integral value. The proper setting of the integrating interval can greatly enhance the accuracy of the detector.
The timer may also control the minimum lengths of time that the presence and absence of a valid ringing signal are indicated for distinctive ringing applications.
Further improvement can be made by the extension of the integrating interval until the integral is outside a range where the presence of ringing signal may be indeterminate. Still further improvement can be made with the addition of a bandpass filter between the telephone line and the ringing detector to attenuate signal frequencies outside the range of valid ringing signals.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block diagram illustrating one application of the invention.
FIG. 2 is a block diagram of one embodiment of the invention.
FIG. 3 is a timing diagram useful in explaining the operation of the embodiment of FIG. 2.
DETAILED DESCRIPTION
FIG. 1 shows a typical application of the ringing detector of the invention. A telephone line circuit has two conductors T and R, commonly designated as tip and ring, respectively. A lightning protection circuit 2 and a high impedance attenuator 4 may be connected across the tip and ring terminals to provide a protected analog output signal of suitable voltage with minimum disturbance of the telephone line circuit. A band pass filter 6 may have its input connected to the output of attenuator 4 and its output connected to the input of a ringing detector 10. The band pass characteristic of filter 6 is not critical; its main purpose is to block dc and interference from power frequencies (50 Hz and 60 Hz) and to pass frequencies in the broad vicinity of ringing signals. As such, it may easily be implemented in any of a number of well known technologies including discrete or integrated components in analog or digital form. In fact, while useful to improve the accuracy of detector 10 of the invention, it is not necessary. Ringing detector 10 may have one or more binary outputs for indicating ringing and no ringing.
A particularly useful embodiment of the ringing detector 10 of the invention is shown in FIG. 2. In this embodiment a magnitude comparator 12 receives its analog input signal Δ TR indirectly from the telephone line circuit. Its output signal PK is a binary signal which may, for example, be high only when the input voltage magnitude is above a convenient predetermined level. That level may correspond to approximately 20 V RMS across the tip-ring pair.
The binary signal PK is fed to a negative transition detector 14, the "RESET" input of a no-ring flip flop 17 and the input of an integrator 18. In this embodiment, integrator 18 is a digital -1 to 31 up/down counter that samples the input at a 1 KHz rate, counts up if the input is high, and counts down if it is low. Integrator 18 holds its count at either limit without resetting. Combinational logic within integrator 18 provides outputs that indicate when the count, therefore the time integral, is at -1, less than 5, less than 8, and less than 16, respectively. A "SET TO ZERO" input momentarily resets the count to zero when it goes high. The invention is not limited to the digital integrator shown; other integrators, both analog and digital can be used to generate a time integral of the PK binary signal.
No-ring flip flop 17 has "Q" output connected to the "SET TO ZERO" input of integrator 18. The "Q" output of flip flop 17 goes high when its "RESET" input goes high, and goes low when its "SET" input goes high. Negative transition detector 14 puts out a pulse on its "TRANS" output when its input goes high to low.
A zero-to-99 millisecond timer 20 has a "CLEAR" input, a "DISABLE" input, a "72" output and a "99" output. When the "CLEAR" input goes low, timer 20 begins counting in milliseconds from zero. Its outputs go high for their respective millisecond count. When the "DISABLE" input is high, the timer stops wherever it happens to be.
A 72-to-99-count latch 22 has inputs connected to the "72" and "99" outputs respectively of timer 20, and a "HOLD" output. The "HOLD" output of latch 22 is high whenever the time count is above 72 milliseconds and below 99 milliseconds. An AND gate 24 has an inverting input connected to the "<5" output of integrator 18 and non-inverting inputs connected to the "72" output of timer 20 and the "<16" output of integrator 18, respectively. The output of AND gate 24 is connected to the "DISABLE" input of timer 20. An AND gate 26 has an input connected to the "72" output of timer 20, an inverting input connected to the "<16" output of integrator 18, and an output "RNGP".
A no-ringing logic circuit 28 has a "NRNG" input, a "72" input connected to the "72" output of timer 20, "<5" and "-1" inputs, connected to the "<5" and "-1" outputs respectively, of integrator 18 and a "NRNGP" output. The "NRNGP" output puts out a pulse whenever inputs "72" and "<5" are both high or inputs "NRNG" and "-1" are both high. A ringing detector output latch 31 has a "SET" input connected to the "NRNGP" output of logic circuit 28, a "RESET" input connected to the "RNGP" output of AND gate 26, and a "Q" output, which goes high when the "SET" input goes high. The "Q" output provides the "NRNG" output signal of this ringing detector embodiment of the invention, and is connected to the "NRNG" input of no-ringing logic circuit 28. A flip flop 34 has a "SET" input connected to the "<8" output of integrator 18, a "RESET" input connected to the output of AND gate 26, and a "Q" output.
As a final part to the embodiment of FIG. 2, a timer control logic circuit 36 has a "CLEAR" output connected to the "CLEAR" input of timer 20 and four inputs. A "TRANS" input is connected to the output of negative transition detecting latch 14, a "NLOAD" input is connected to the "Q" output of flip flop 17, an "INH" input is connected to the "Q" output of flip flop 34, and a "HOLD" input is connected to the "HOLD" output of latch 22.
The "CLEAR" output of logic circuit 36 goes high whenever the "HOLD" input is low in combination with either the "NLOAD" input being low or both the "INH" and "TRANS" inputs being low.
The operation of the embodiment of FIG. 2 will be explained with reference to FIG. 3, which is a timing diagram that shows signals that may exist simultaneously at various locations throughout the circuit. Each signal is labeled according to its physical location in the diagram of FIG. 2.
Δ TR, the signal on the first line of FIG. 3 is the attenuated and filtered version of the differential tip-ring voltage of the telephone line circuit, and the only analog signal in this diagram. Dotted lines 36 and 38 represent the voltage levels that correspond to the switching levels of magnitude comparator 12. When the circuit is first turned on, an initializing pulse is fed to the "INIT" inputs of flip-flops 17 and 34 and latches 22 and 31. As a result, NLOAD is low, INH is high, NRNG is high, and the logic in latch 22 is cleared. Its "HOLD" output is therefore low.
When Δ TR first exceeds level 36, therefore, PK goes high; flip-flop 17 is reset, driving NLOAD high and resetting integrator 18 to zero; and integrator 18 starts counting up at a rate of one count per millisecond. At the same time, HOLD being low, when NLOAD goes high, the "CLEAR" output of timer control logic 36 goes low, and millisecond timer 20 starts at zero.
Integrator 18 counts up when PK is high and down when PK is low. Signals <5, <8 and <16 go low after 5, 8 and 16 milliseconds, respectively. When Δ TR drops below level 36, PK goes low and integrator 18 begins to count down. At the same time, negative transition detector 14 momentarily goes low. The <16 signal may go high for a short interval as the count of integrator 18 dips back below 16 during a "count-down" period. Since Δ TR soon drops below level 38, however, the PK signal from magnitude comparator 12 again goes high, and integrator 18 soon counts above 16 again to its maximum count, 31. The count remains near 31 as long as the strong ac signal continues across the TIP-RING pair, lowering periodically during the short count-down intervals and rising right back to 31 during the longer count-up intervals.
When timer 20 reaches 72 milliseconds, signal 72 goes high, causing HOLD to go high. This prevents timer 20 from resetting. At the same time, <16 being low, AND gate 26 is enabled for 1 msec. The resulting RNGP high signal resets latch 31, indicating that valid ringing is present, and latch 34, causing INH to go low. Had the count in integrator 18 at this 72 millisecond point been less than 5, signals <16 and <5 and would both be high, and NR logic circuit 28 would have been enabled instead of AND gate 26. As a result, signal NRNGP would go high for one millisecond, reaffirming no valid ringing signal present and setting flip-flop 17. In the event, when timer 20 reaches 72 msec the count in integrator 18 is between five and sixteen, signal <5 is low, but <16 high. This combination enables AND gate 24 to disable timer 20 at 72 msec, where it remains until <5 goes high or <16 goes low. Thus if the presence of valid ringing is not determined at 72 msec, the circuit waits until it can be determined. A series of transients or a transient coincident with valid ringing can cause this condition.
Since HOLD signal remains high, timer 20 continues to count. At 99 msec, the HOLD signal goes low, and timer 20 recycles through zero. About 8 milliseconds later, the TRANS signal from transition detector 14 momentarily goes low in response to the PK transition from high to low. Since both HOLD and INH are also low, CLEAR goes high, and timer 20 restarts at zero. This continues to happen each time TRANS goes low until the ringing signal disappears and the integral count drops below 8, causing INH to go high again. In this manner, the end of each ringing pulse is accurately timed. The NRNG output signal, however, does not change at this point. It is only when timer 20 has reached 72 msec, again, and the count in integrator 18 has dropped below 5, that logic circuit 28 is enabled to set latch 31 and indicate NO RINGING . At 72 msec, HOLD again goes high to prevent clearing of timer 20, and the NRNGP pulse sets flip-flop 17 to drive NLOAD low.
Since the indication of RINGING was delayed 72 msec from when the input waveform first exceeded threshold 36, the length of the ringing pulse is accurately reproduced by the NRNG binary output signal, no matter how long. Since the NRNG output signal, however, can only be changed via a pulse from gate 26 or logic circuit 28, caused by a timer count of 72, and restarting is prevented until the timer reaches 99, its full cycle, the minimum time for either a RINGING or NO RINGING output indication is the full cycle time of counter 20,100 msec. This is a requirement for a known distinctive ringing application. This minimum time can readily be changed by simply changing the full cycle time of timer 20, and output "99" to match. Similarly, if different minimum RINGING and NO RINGING indication times are desired, different timer counts should enable gate 26 and logic 28, respectively.
When timer 20 reaches 99 msec again, the HOLD signal goes low. In the absence of Δ TR voltage high enough to exceed the switching level of comparator 12, NLOAD remains low, and the CLEAR signal from logic circuit 36 keeps timer 20 cleared at zero.
When a transient pulse appears on Δ TR, at the right side of FIG. 3, it can be seen that integrator 18 counts up briefly, but counts down to -1 before timer 20 reaches 72 msec. The combination of NRNG and <1 enable logic circuit 28; the resulting pulse on NRNGP sets flip-flop 17, and timer 20 is again cleared. The transient pulse does not result in ringing detection. The embodiment of FIG. 2, therefore, discriminates between valid ringing and transients by timing the integral of PK for 72 msec; this specific time interval is obviously not critical to the invention. A person of ordinary skill in the art can alter it to suit the conditions of any particular application.
The embodiment of FIG. 2 can be readily assembled by persons skilled in the art from available components. Latches 22 and 31, negative transition detector 14, and logic circuits 38 and 36, for example, can be made from a combination of simple logic gates. Timer 20 and integrator 18 each might include a source of 1 msec clock pulses, a counter, and decoding logic to provide the necessary output values. The 1 msec clock can, of course, be shared. Flip-flops 17 and 34 can be of the variety in which the data is clocked in (using a higher frequency clock such as 128 KHz, eg.) to prevent race conditions. Finally, magnitude comparator 12 can be implemented by a full wave rectifier, a differential amplifier and and a reference voltage source. The particular combination of logic gates and counters used to implement either the embodiment of FIG. 2 or other embodiments of the invention are not critical. In fact, skilled designers can readily design other circuits that determine the percentage of time an input waveform exceeds a predetermined magnitude over a predetermined minimum time interval in order to distinguish among various signals without departing from the spirit and scope of our invention. | To accurately detect the short bursts of distinctive ringing signals within 100 milliseconds, a magnitude comparator produces a binary signal indicative of whether the instantaneous tip-ring voltage exceeds a predetermined magnitude. The binary signal is integrated over a predetermined period of time controlled by a timer. If the time integral is below a first predetermined value, the absence of ringing is detected; if above a second predetermined value, ringing is detected; if in between, the integrating interval is extended until the integral falls outside the two values. | 7 |
This invention relates to a docking system for handheld electronic communication devices such as cellular telephones or the like, for use with structures or vehicles This application is a division of Ser. No. 12/378,452, filed Feb. 13, 2009 now U.S. Pat. No. 7,904,124, which is a continuation of Ser. No. 12/218,324, filed Jul. 14, 2008, now Patented as U.S. Pat. No. 7,881,664, which is a continuation of Ser. No. 11/728,487, filed Mar. 26, 2007, now Patented as U.S. Pat. No. 7,421,253, which is a continuation of Ser. No. 11/115,020, filed Apr. 26, 2005, now Patented as U.S. Pat. No. 7,580,733, which is a continuation of Ser. No. 11/020,450, filed Dec. 22, 2004, now Patented as U.S. Pat. No. 7,400,858, which is a continuation of Ser. No. 10/619,770, filed Jul. 15, 2003, now Patented as U.S. Pat. No. 7,197,285, which is a continuation of Ser. No. 09/634,140, filed Aug. 08, 2000, now Patented as U.S. Pat. No. 6,885,845, which is a Continuation-in-part of Ser. No. 09/009,220, filed Jan. 20, 1998, now Patented as U.S. Pat. No. 6,112,106, which is a continuation of Ser. No. 08/604,105, filed Feb. 20, 1996, now Patented as U.S. Pat. No 6,594,471; and this application is also a continuation of U.S. patent application Ser. no. 12/218,324, filed Jul. 14, 2008, now U.S. Pat. No. 7,881,664, issued Feb. 01, 2011, which is a continuation of U.S. patent application Ser. No. 11/020,450, filed Dec. 22, 2004, issued on Jul. 15, 2008 as U.S. Pat. No. 7,400,858, and patent application Ser. No. 11/728,487, which is a continuation of Ser. No. 10/619,770, now U.S. Pat. No. 7,197,285, which are each a continuation applications of Ser. No. 09/634,140, filed Aug. 08, 2000, now U.S. Pat. No. 6,885,845, which is a continuation of Ser. No. 08/604,105, filed Feb. 20, 1996, now U.S. Pat. No. 6,594,471, each of which, and their U.S. Patent Office file histories, are all incorporated herein by reference in their entirety, and is a Continuation-In-Part Application of U.S. patent application Ser. No. 08/581,065, filed Dec. 29, 1995, which is a Continuation-In-Part Application of our allowed U.S. patent application Ser. No. 08/042,879, filed Apr. 5, 1993, each being incorporated herein by reference, in their entirety.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
(2) Prior Art
Extraneous radio frequency emission has become a serious concern of hand-held electronic communication devices such as portable facsimile machines, ground position indicators, and cellular telephone manufacturers and users alike. RF radiation is considered a potential carcinogen.
The proliferation of these hand-held devices is evident everywhere. A single hand-held device however, should able to travel with its owner and be easily transferably usable in automobiles, planes, cabs or buildings (including hospitals) as well as at offices and at desks with no restrictions on their use. And without causing concern with regard to the radiation therefrom. The hand-held devices should be portable for a user to carry in his pocket, yet be able to use that same cellular unit in such vehicle or building while minimizing such radiational effect therein.
It is an object of the present invention to permit a user of a portable hand-held electronic communication device such as a cellular telephone or the like, to conveniently use that same hand-held device/cellular phone in an automobile, plane or building, office/desk, or anywhere signal transmission is needed, and to permit such signal to reach its intended destination such as a communications network or satellite, without interfering with other electrical equipment and in spite of interfering walls of buildings or structure and/or other electrical equipment.
It is a further object of the present invention to minimize any radiation from such a portable device, such as a cellular telephone or the like, while such use occurs in an automobile, a building or an elevator, an airplane, a cab, or other public facility in which the user wishes to minimize his own exposure to stray radiation, and also to permit re-transmission of his signal, to avoid the necessity of connecting and disconnecting cables, and to permit a wide variety of cellular telephones such as would be utilized in a rental car where various manufactures' phones would be used, and to permit control of such re-transmission of signals where desired, so as to allow user/customer billing and monitoring thereof.
BRIEF SUMMARY OF THE INVENTION
The present invention comprises a docking system adaptable to an automobile, plane, building or desk for receipt of an electronic communication device such as a cellular telephone, portable computer, facsimile machine, pager or the like, to permit a user safe, environmentally safe, non-touching, radiationally communicative mating of the antenna of that device to a further transmission line through a juxtaposed pick-up probe, the signal coming in or going out through a communications network or further remote antenna.
The docking system may comprise a “zone” or “focal area” as a generally rectilinear area/volume on/in a desk or work surface on/in which the electronic communication device may be placed, such a surface or space being possible on a desk, or in a plane. That focal area may also, in a further embodiment, be comprised of one or more rooms in a building, such focal area having a pick-up probe thereat, in conjunction with a shield placed on/in the desk, room, vehicle or building to prevent the radiation from that communication device from traveling in any undesired directions within the desk, room, vehicle or building.
The focal area may be defined by a metal walled structure within or on which a broadband probe is arranged. The metal walled structure acts as a shield to minimize radiation from the communication device from passing therethrough. In a first embodiment, the shield may be comprised of a partial housing disposed within the upper work surface of a desk. The probe would be elongatively disposed within the partial housing and be in electrical communication with a transmission line such as coax cable, waveguide, or the like. The partial housing may have a planar dielectric layer thereover, which would also be co-planar with the surface of the desk. The communication device would be placed within the pickup zone of the focal area, and would be able to transmit and receive signals through the dielectric layer. The partial housing would act as the shield in the desk, to minimize radiation by the worker at the desk. In a further embodiment, the housing may be comprised of a thin, generally planar mat of conductive material, which mat may be flexible and distortable, for conformance to a particular work surface and for ease of storage capabilities. The mat has an upper layer of dielectric material (for example, plastic, foam or the like). A thin, flat, conformable coupling probe may be embedded into or printed onto the upper surface of the dielectric material. The mat may be utilized as a portable focal area for placement of a communication device thereon, or wrapped up in an enveloping manner therein.
A yet further embodiment of the present invention includes a control unit in the transmission line from the pickup probe to the further remote antenna. The control unit may comprise a filter or switch connected to a computer. The computer may accumulate billing information, control system functions, or act as a regulator for multiple users of the antenna coupling system.
The invention thus comprises a docking system for connecting a portable communication device to a further signal transmission line, the portable communication device having an externally radiative antenna, the system comprising a shield for restricting at least a portion of any radiation from the externally radiative antenna of said portable communication device, and a coupling probe mounted adjacent to the shield for radiatively coupling between the externally radiative antenna of the portable communication device and the further signal transmission line via radio frequency energy therebetween. The shield may be comprised of an electrically conductive material, or an attenuative material capable of blocking at least part of the radiofrequency radiation energy coming from the communication device(s) connected thereto. The shield defines a focal area for receipt and transmission of a radio frequency signal, when a communication device is placed within the focal area. The focal area or zone, may be selected from the group of structures consisting of a desk, a room in a building, or a tray or the like in a vehicle. The further signal transmission line may be connected to a further communication network and/or a further antenna connected to the transmission line, yet positioned at a location remote from the shield. The transmission line may have a control unit therein, the control unit being arranged to permit regulation of signals being transmitted through the transmission line. The control unit may comprise a computer arranged to monitor time or use of the docking system. The shield and the probe may be spaced apart by a dielectric material. The shield, the probe and the dielectric material may be flexible. The communication device may include at least two cellular telephones (or other portable communication devices) simultaneously connected to the remote antenna.
The invention also includes a method of coupling a portable communication device having an externally radiative antenna, to a signal transmission line having a further remote antenna thereon, for the purpose of effecting radio signal transmission therebetween, the method comprising the steps of arranging a radiation shield in juxtaposition with at least a portion of said radiative antenna of the portable communication device, mounting a coupling probe adjacent the shield and in communication with the signal transmission line, and placing the externally radiative antenna of the portable communication device close to the probe and the shield so as to permit radiative communication between the externally radiative antenna and the signal transmission line via the coupling probe. The method may include arranging the shield in or on a generally planar work surface so as to restrict the propagation of at least a portion of the radiation emanating from the communication device primarily only to the vicinity of the probe. The method may include attaching a control unit to the transmission line to permit regulation of electric signals therethrough, and adding a further communication device in juxtaposition with a further probe, the further probe also being in electronic communication with that control unit, so as to permit multiple simultaneous use of the transmission line and communication system and/or remote antenna therewith. The method of coupling the portable communication device to the signal transmission line, may also include the step of billing any users of the communication and/or remote antenna by monitoring and tabulating any signals received by and sent through the control unit.
It is an object of the present invention to provide a shielded antenna docking arrangement, which itself may be portable, for use with a portable communication device such as a cellular telephone, facsimile machine or ground position indicator or the like, such use occurring in a vehicle such as a plane, an automobile or a cab or in a public or private building, office desk or elevator.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and advantages of the present invention will become more apparent when viewed in conjunction with the following drawings in which:
FIG. 1 a is a perspective view of a focal area docking arrangement, as may be utilized with a desk;
FIG. 1 b is a partial view taken along the lines A-A of FIG. 1 a;
FIG. 2 a is a perspective view of a portable focal area docking system for portable communication devices;
FIG. 2 b is a view taken along the lines B-B of FIG. 2 a;
FIG. 3 a is a block diagram of a docking system having a sensor unit arranged therewith;
FIG. 3 b is a block diagram of a further embodiment of that shown in FIG. 3 a ; and
FIG. 4 is a side elevational view of a docking system, as it may be utilized in a vehicle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings in detail, and particularly to FIG. 1 a , there is shown a portable communication device docking arrangement 10 , to permit a portable communication device such as a hand-held cellular telephone 12 to be utilized thereon, such as on a desk 14 or adjacent to it, and as a personal communicator (i.e. cellular telephone, facsimile machine, pager or the like) which may also be carried on an individual.
Such a docking system 10 of the present invention may also be adaptable to an automobile, plane, or building for providing radiationally restrictive communication between a portable electronic communication device 12 such as a cellular telephone, portable computer, facsimile machine, pager, or the like, while allowing communicative mating of the radiative antenna of that device to a further transmission line and communication system and/or a more remote antenna, as recited and shown in our aforementioned patent applications, incorporated herein by reference in their entirety.
The docking system 10 may comprise a “zone” or “focal area” 16 as a rectilinear area/volume on/in a desk 14 or work surface on/in which the electronic communication device 12 may be placed, such a surface or space being in a structure such as an airplane. That focal area 16 has a pick-up coupling probe 22 thereat, as shown for example in FIG. 1 b , in conjunction with a shield 24 placed on/in the desk 14 , (or room, vehicle or building, as shown in FIGS. 3 a and 3 b ), to prevent the radiation (electromagnetic/microwave) emanating from that communication device 12 from traveling in any undesired directions within the desk, room, vehicle or building.
The focal area 16 may be defined by a metal walled housing structure 30 within which a broadband probe 22 is arranged, as shown in FIG. 1 b . The metal walled structure 30 acts as a shield to minimize undesired radiation from the communication device 12 from passing therethrough. In a first embodiment, the shield may be comprised of a partial housing 34 disposed within the upper work surface 36 of a desk 14 , as may be seen in FIG. 1 b . The pick-up probe 22 would be elongatively disposed within the partial housing structure 30 and be in electrical communication with a transmission line 32 such as coaxial cable, waveguide, or the like. The transmission line 32 would be in electrical communication with an electric communications network or distribution system 38 , and/or to a further remote antenna 40 , such as may be seen in FIGS. 1 b , 3 a and 3 b . The partial housing 30 may have a planar dielectric layer 42 thereover, which would also be co-planar with the surface of the desk 14 . The communication device 12 would be placed within the pickup zone of the focal area 16 , and would be able to transmit and receive signals through the dielectric layer 42 . The partial housing 30 would act as the shield in the desk, to minimize radiation directed towards the worker(s) at the desk.
In a further embodiment as shown in FIG. 2 a , the shield or housing may be comprised of a thin, generally planar mat 50 of conductive material, which mat 50 may be flexible and distortable, for conformance to any surface (human or otherwise), and may be folded or rolled up to minimize storage requirements. The mat 50 has an upper layer 52 made of a dielectric material (plastic, foam or the like). A thin, flat, conformable coupling probe 54 is embedded into or printed onto the upper surface of the layer of dielectric material 52 . The mat 50 may be utilized as a portable focal area for placement of a communication device thereon, or wrapped-up in an enveloping manner therein. The probe 54 is connected to a transmission line 56 , in electrical contact with a network or remote antenna, not shown in this figure.
A yet further embodiment of the present invention includes a control unit 60 , connected into the transmission line 62 from the pickup probe 64 to the further remote antenna 66 shown in FIGS. 3 a and 3 b . The control unit 60 may comprise a filter, switch, amplifier, attenuator, combiner, splitter, or other type of frequency converter, connected to a computer 68 . The computer 68 may be arranged to accumulate customer or billing information by functioning with a processor to print out use-data 69 , to maintain frequency control functions, or to act as a regulator for multiple users of the antenna coupling system 10 . There may be a plurality of pickup coupling probes 64 each connected to the control unit 60 and the transmission line 62 . one probe 64 in each of a plurality of shielded rooms 65 , each wall or work area (desk) having a shield, the rooms 65 , each wall or work area (desk) having a shield, the rooms 65 shown in a building 67 , in FIG. 3 b.
The view shown in FIG. 4 , displays a portable communication device such as a facsimile machine or computer 70 supported on a tray 72 articulably mounted on the back of an airplane seat 74 . The tray 72 has a “focal area” 75 therewithin, as represented by the dashed lines 76 . The focal area 75 includes a conductive (preferably metallic) shield arranged beneath and partially surrounding a broadband probe 77 . The probe 77 transmits electrical signals radiated to and from a radiative antenna on or in the base of the portable communication device 70 . A transmission line 78 which may be comprised of coaxial cable, waveguide, or optical fibers, extends the probe within the focal area, to a further remote antenna 80 mounted outside of the structure, which here, is identified as an airplane.
A control unit 82 , such as attenuators, heterodyne converters, amplifiers, bandpass filters, switches, or the like, may be arranged in communication with the transmission line 78 to monitor or control the time in the vehicle in which the communication device may be utilized, for example, to limit certain times when such devices may be utilized in an airplane, or to modulate the signal being transmitted or received by the remote antenna, and/or to monitor usage of the docking system for subsequent billing of those users.
Thus what has been shown is a unique system for minimizing the detrimental effects of radiation from common portable communication devices to their users, while improving the transmission capabilities and customer usage of such devices, overcoming the barriers such as, buildings and vehicles in which such devices might otherwise be utilized, that would interfere with the flow of signals transmitted. | The present invention comprises a docking system for connecting a portable communication device to a further signal transmission line. The docking system may be arranged within a workstation such as a desk or a tray. The system may also envelope a room in a building or be located in a vehicle, to control and restrict the radiative emission from the communication device and to direct such radiation to a further remote antenna and or signal distribution system connected to the transmission line. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
Priority is claimed with respect to European Patent Application No. 00810430.9-2304 filed on May 17, 2000, in the European Patent Office, the disclosure of which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
The invention relates to a device for delivering a printing plate to a plate cylinder of a printing press in a position ready for exchange where one printing plate edge can be transferred to a holding fixture on the plate cylinder.
A known device of this type, disclosed in EP 0 714 771 A2, comprises a linear drive for gripping devices arranged on the printing press machine frame near the plate cylinder. These gripping devices can be advanced tangentially toward the plate cylinder. A suspension bar supported on pivoting arms extends parallel to the axis of rotation of the plate cylinder. The front edge of the printing plate to be secured is suspended from the suspension bar in a position where it can be pivoted for transferring the printing plate. The suspension bar is subsequently pivoted in the direction of the plate cylinder, thus moving it into the movement path of the gripping devices. The gripping devices guide the printing plate with its angled, front edge to an axial plate channel of the holding fixture, formed in the outer periphery of the plate cylinder. As a result, the printing plate with its angled edge can be secured tightly in the plate channel. The plate cylinder with the secured front edge of the printing plate is then rotated. The printing plate is consequently wound onto the printing cylinder until its rear edge, which is also angled, engages and is secured either in the same plate channel of the front edge or in a different one.
Another known device, disclosed in EP 0 567 754 A1, is provided with a roller and, at a distance thereto, a suction cup is arranged on a section of a printing mechanism guard on the printing press, which can be tilted upward. The printing plate to be secured is supported on the roller and held in place by the suction cup. When the hinged-on printing mechanism guard is in the tilted-up position, the section that supports the roller and the suction cup is positioned in such a way, relative to the plate cylinder, that the printing plate held by the roller and the suction cup is aligned tangential to the plate cylinder and can be supplied correctly positioned to its holding fixture.
A known method of storing the printing plate to be secured inside a magazine, disclosed in DE 195 08 844 A1, is provided with transporting means for pushing out the printing plate. Relative to the plate cylinder, this magazine is arranged on the printing press in such a way that the printing plate, which is pushed out by the transporting means, is placed with its front edge into the correct position for securing it in the holding fixture of the plate cylinder.
All of these conventional devices require that the position for exchange, in which the front edge of the printing plate to be secured is transferred to the holding fixture of the plate cylinder, is clearly determined. The conventional devices are therefore designed only for a single printing plate format and size. Plate cylinders for different printing plate formats, however, have different diameters. As a result, the holding fixtures for the plate cylinders with different diameters occupy correspondingly different positions in the printing press.
SUMMARY OF THE INVENTION
It is an object of the invention to create a device of the aforementioned type, which permits the operation with different formats.
The above and other objects are solved according to the invention by assigning a number of exchangeable format slide-in units to the printing press. These units can be inserted optionally into the printing press and accommodate the respective plate cylinder with a diameter corresponding to the selected format. The delivery mechanism is provided with a number of settings that correspond to the number of format slide-in units and determine the position of exchange that corresponds to the respectively inserted format slide-in unit.
The format slide-in units are designed to fit into a specially provided receptacle on the printing press and are driven by the latter, independent of the format dependent diameter of the plate cylinder. The plate cylinder, the rubber cylinder engaged therewith and, if necessary, a counter pressure cylinder that meshes with the rubber cylinder are respectively positioned inside the format slide-in units. The rotational axes for these cylinders and their cylinder jackets occupy different positions in the various format slide-in units because of the format dependent different radii. According to the invention, the different settings of the delivery mechanism take into account the correct changing position for the respective printing plate to be secured for each inserted format slide-in unit.
According to a particular embodiment of the device according to the invention, a positioning element determines the setting on each format slide-in unit for an opposing element. The opposing element, which can be made to engage in the positioning element, is provided on a printing plate guide element that aligns the outer edge of the printing plate to be secured. During a format change, only the printing plate guide element must be released from the engagement between its counter element and the positioning element for the format slide-in unit to be exchanged. Following the insertion of the new format slide-in unit, it must again be made to engage with its positioning element. For this, the printing plate guide element can be suspended freely moving on a suitable support device, so that its inherent weight is essentially supported during this operation and is available within grasping distance of the printing press, even in the state where it is not engaged with the positioning element.
The positioning element for the aforementioned embodiment of the format slide-in unit delivers the necessary position information for the respective setting of the delivery mechanism. In contrast, a holding fixture 28 (FIG. 2) can be provided according to an alternative embodiment, which is supported on a stationary section accommodating the format slide-in unit, in particular on the printing press. This holding fixture is connected with one free end to a printing plate guide element that aligns the edge of the printing plate to be secured and has an adjusting mechanism 30 (FIG. 2) for the number of settings for the free end that correspond to the positions for exchange. In that case, the adjusting mechanism for the holding fixture contains the information necessary to determine the appropriate positions of exchange for the various format slide-in units. This adjusting mechanism could be an articulated mechanism, for example, which snaps into various angular positions that correspond to the positions for exchange.
In that case, a manual selection of the appropriate setting on the adjusting mechanism by an operator exchanging the respective format slide-in unit does not result in a special expenditure. However, the embodiment can conceivably be modified in such a way that the printing press is provided with a sensor 32 (FIG. 2) for detecting the respectively used format slide-in unit, as well as an actuator for the automatic selection of the respective setting in response to the detection signal from the sensor.
The printing plate guide elements for the aforementioned embodiments, which may include one or several guide rollers on a support frame that can change position, function to correctly align the edges of the printing plates to be secured. In another modification of the invention, this guide element is designed such that it can be moved from the respective position of exchange to a stand-by position. The guide element is removed from the printing press in this stand-by position relative to the changing position. This permits good access during the format exchange, an unobstructed course for the printed pages during the printing operation and, at the same time, an easier loading of a new printing plate.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional features, details and advantages of the invention follow from the description below, as well as the following figures.
FIG. 1 shows a side view of a printing press with a slide-in unit and a mechanism for delivering a printing plate in the position for exchange in accordance with the present invention.
FIG. 2 shows the printing press in FIG. 1 with the delivery mechanism in a stand-by position.
FIG. 3 shows a side view of a printing press with an alternative embodiment of the invention with a mechanism for delivery corresponding to printing plate cylinders of a smaller format.
FIG. 4 shows the printing press of FIG. 3 with the delivery mechanism in a stand-by position.
DETAILED DESCRIPTION OF THE INVENTION
A printing press 1 , shown in FIGS. 1 and 2, is provided in a known manner with a plate cylinder 2 , a rubber cylinder 3 and a counter-pressure cylinder 4 . The rotational axes 5 , 6 , 7 of these cylinders extend perpendicular to the drawing plane and are positioned with their ends in the axially spaced apart side parts 8 of a format slide-in unit 9 , which extend parallel to the drawing plane.
Two axially spaced apart side parts 10 of the printing press 1 extend parallel to the side parts 8 of the format slide-in unit 9 , into which the format slide-in unit 9 is inserted such that it can be exchanged. The rotational axes 5 , 6 , 7 in this case are positioned in the side parts 8 of the format slide-in unit 9 in such a way that the joint operation in the correct position with the non-replaceable remaining elements of printing press 1 , particularly the elements for driving the format slide-in unit 9 , is ensured once the format slide-in unit 9 is inserted.
The plate cylinder 2 is provided with a plate channel 12 , which extends in axial direction and is open toward its cylinder jacket 11 . In order to secure a printing plate 13 on the plate cylinder 2 , the front edge 14 of the printing plate 13 is angled in such a way that it can be inserted in an approximately radial direction into the plate channel 12 . The printing plate 13 can be secured with clamping means that are not shown in FIGS. 1 and 2. Following this, the plate cylinder 2 in FIG. 1 is turned in clockwise direction. As a result, the printing plate 13 is pulled through the cylinder gap, formed between the plate cylinder 2 and the rubber cylinder 3 , and is fitted against the cylinder jacket 11 of plate cylinder 2 . The format of printing plate 13 and the diameter of plate cylinder 2 are matched to each other in such a way that in the end, the equally angled rear edge 15 of printing plate 13 enters the plate channel 12 as well and is secured there.
Since the printing plate 13 must be exchanged relatively frequently, a mechanism 16 for delivering the printing plates 13 to the position for exchange at the plate cylinder 2 is provided to facilitate this operation. The delivery mechanism 16 , shown in FIG. 2 in a stand-by position that is somewhat removed from the printing press 1 , is provided for the embodiment shown with a suspension element 17 , which can be displaced locally, relative to the printing press 1 . The delivery mechanism 16 furthermore is provided with a hinged-on frame element 18 , which is attached such that it can pivot. The free end of this frame element, which is located opposite the suspension element 17 , has an angled section 19 that matches the angled front edge 14 of the printing plates 13 . Near this angled section 19 , a printing plate guide element 20 and at a distance thereto at least one support roller element 21 are arranged on the frame element 18 . The printing plate guide element 20 supports at least one guide roller 22 , which can be displaced essentially crosswise to the plane for frame element 18 and a thereon arranged printing plate 13 . The printing plate guide element can also be provided with a pneumatic actuator.
The stand-by position for the delivery mechanism 16 , shown in FIG. 2, is suited for fitting a printing plate 13 in such a way that it strikes with its angled front edge 14 against the angled section 19 of the frame element 18 and that it rests with its planar surface on the support roller element 21 and the guide roller 22 . To keep the inserted printing plate 13 securely in the inserted position, guides, holders, or counter-rollers can be provided, which hold the printing plate 13 in the contacting position against the printing plate guide element 20 . Furthermore, the support roller elements 21 as well as the guide rollers 22 are preferably arranged in pairs for supporting the two edge regions of printing plate 13 .
Respectively one positioning element 23 is provided according to FIGS. 1 and 2 on both side parts 10 of the format slide-in unit 9 . In the exemplary embodiment shown here, the positioning element 23 takes the form of a guide groove that is open toward the free edge 24 of the side parts 10 and is closed on the opposite end 25 . The guide groove serves as positioning element for the front area 26 of frame element 18 with complementary design, which holds the printing plate guide element 20 . The mechanism 16 is moved from the stand-by position, shown in FIG. 2, to the position for exchange, shown in FIG. 1, by inserting the front area 26 of the frame element 18 , designed as a counter element 26 a , into the guide groove forming the positioning element 23 with the aid of a translatory displacement of the suspension element 17 and by pivoting the frame element 18 . In the process, the closed end 25 and the inclination of the positioning element 23 determine the position and orientation of the delivery mechanism 16 for the respective format slide-in unit 9 required for the position of exchange. FIG. 1 shows that, for example, through a pneumatic displacement of the guide roller 22 toward the cylinder jacket 11 of plate cylinder 2 , the angled front edge 14 can be inserted in this position into the plate channel 12 , which is turned toward the position for exchange. The previously described clamping operation can then be carried out.
The representations in FIGS. 3 and 4 differ from the representations in FIGS. 1 and 2 only in that a different format slide-in unit 9 ′ for a different format is inserted into the printing press 1 . All other elements are the same.
The format slide-in unit 9 ′ differs from the format slide-in unit 9 only with respect to the position of the rotational axes 5 ′, 6 ′, 7 ′ of the plate cylinder 2 ′, the rubber cylinder 3 ′ or the counter-pressure cylinder 4 ′, as well as the cylinder diameter. In accordance with the smaller format used in FIGS. 3 and 4, these diameters are smaller than in FIGS. 1 and 2. This difference in the design, relative to FIG. 1, which results from the change in the position for exchange, is taken into account through the difference in the guide groove design relative to its slant and the position of closed end 25 ′. This guide groove functions as positioning element 23 ′ on the side parts 10 ′ of format slide-in unit 9 ′. Thus, if the delivery mechanism is inserted, as described with the aid of FIG. 1, with its frontal area 26 that functions as counter element into the guide groove 23 ′, the delivery mechanism assumes the position of exchange that is appropriate for the exchanged format slide-in unit 9 ′, as shown in FIG. 3 .
As an alternative to the illustrated and described embodiment, an adjusting mechanism could be provided for the translatory movement of the suspension element 17 and the pivoting movement of frame element 18 instead of the positioning elements 23 , 23 ′ and the counter elements in the frontal area 26 . The number of settings of this adjusting mechanism corresponds to the number of positions for exchange and the device thus assumes the correct position for exchange for each format slide-in unit 9 . Instead of selecting these settings by hand, the printing press 1 could be provided with a sensor for the respective format slide-in unit 9 , 9 ′, the output signal of which is used for an automatic selection of the corresponding settings.
The invention has been described in detail with respect to preferred embodiments, and it will now be apparent from the foregoing to those skilled in the art, that changes and modifications may be made without departing from the invention in its broader aspects, and the invention, therefore, as defined in the appended claims, is intended to cover all such changes and modifications that fall within the true spirit of the invention. | A device for delivering a printing plate having at least one edge to a plate cylinder of a printing press in a position for exchange is provided. The device includes at least one selectable exchangeable format slide-in unit insertable into the printing press. The format slide-in unit is selected to accommodate the plate cylinder. The device also includes a delivery mechanism with a number of settings corresponding to the selected format slide-in unit. The delivery mechanism determines the position of exchange that corresponds to the selected format slide-in unit. | 1 |
This is a continuation of patent application Ser. No. 220,445 filed Dec. 12, 1980, now abandoned, which is a continuation of application Ser. No. 55,609, filed July 9, 1979, now abandoned.
BACKGROUND OF THE INVENTION
The ever-increasing need for high quality mineral crystals, particularly as the building blocks for electronic components, has resulted in substantial progress in the development of techniques for growing synthethic crystals. One of the most successful techniques is the Czochralski or pulling methods. The pulling method is useful for growing crystals from the melt, when the crystal melts congruently, when the melt is of a low volatility, and when vessels which are non-reactive with the melt are available. The pulling method involves contacting a seed crystal with the surface of a nutrient melt and drawing the seed crystal away from the melt as the crystal grows at the interface. One drawback however, is that the resulting crystal is normally circular in cross-section. Because a circular cross-section is not the most economic from a processing point of view, it is desirable to somehow change this charcteristic of the system. One approach might be to isolate a certain area of the surface of the melt using a solid mask. The problem with a mask is that it would be very difficult to keep it from deteriorating due to the high temperature and reactivity of the nutrient melt for the period of time necessary to grow the crystals. This deterioration problem results in two unfavorable effects: first, the cross-sectional shape of the mask will change with time and thus cause an inconsistent crystal product and, second, the deteriorating mask will add impurities to the melt whose composition must be controlled within critical limits. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a system for growing crystals of a desired cross-section and, more specifically, crystals in sheet form.
Another object of this invention is the provision of a masking technique for use in the crystal pulling method.
A further object of the present invention is the provision of a masking technique for use in high temperature melts which does not contaminate the melt.
It is another object of the instant invention to provide a simple and relatively inexpensive method for providing electronic quality crystals of a shape which is optimum for subsequent processing.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.
SUMMARY OF THE INVENTION
This invention involves a system for formation of mineral crystals having a regular cross-sectional shape, this system comprising a crucible, a mass of nutrient melt within the crucible, a heater for maintaining the melt at a first temperature, and a cooling element at the surface of the melt. Pulling apparatus is provided for contacting a seed crystal with the growing zone and then drawing the seed crystal away from the growing zone as the melt crystalizes on the seed crystal. A cooling fluid passes through the cooling element at a rate which controls the cooling effect of the element. The cooling effect is adjusted to allow a layer of solid nutrient melt to form around the cooling element and to protect it from the melt temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated by the accompany drawings, in which:
FIG. 1 is a perspective view of apparatus embodying the principles of the present invention,
FIG. 2 is a cross-sectional view of the apparatus of the present invention taken along line II--II of FIG. 1, and
FIG. 3 is a vertical sectional view of a modified form of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, in which are shown the general features of the present invention, the crystal growing system, indicated generally by the numeral 10, is shown to include a nutrient source 11, a masking system 12, and a pulling system 13. The nutrient source 11 includes a crucible 14 for containing a body of nutrient melt 15. The crucible material will be chosen to be non-reactive with the nutrient at the temperature of the melt. The nutrient in the preferred embodiment would be ultra-pure silicone. The nutrient would be melted using ratio frequency heaters 16.
The masking system 12 consists primarily of cooling tubes 17 which are partially submerged in the surface of the nutrient melt 15 to divide the surface into a growing zone 18 and a non-growing zone 19. The cooling tubes in the preferred embodiment would be made of copper, but might also be formed of a material, such as quartz, that is resistant to high temperature. Through the tubes is passed a cooling fluid 21. The cooling fluid 21 is fed to the cooling tubes 17 from a cooling fluid source 22 and through valves 23 and 24. The cooling fluid 21 passes from the tubes at exits 25 and 26. The rate of flow of the cooling fluid 21 through the cooling tube 17 is controlled by valves 23 and 24. This rate is selected at such a value as to carry away heat in sufficient amounts to allow a layer of solidified nutrient 27 to form around the outside of the cooling tubes 17. This layer of solid nutrient 27 formed around the cooling tubes has three functions. First, it physically isolates the material of the cooling tubes from the nutrient melt to avoid contamination of the ultra pure nutrient melt. Second it thoroughly insulates the cooling tubes from the melt which would normally be at a temperature far in excess of the melting point of the material from which the tubes are made. The flow of coolng fluid in the masking system would be adjusted so that the melting temperature of the material from which the cooling tubes are made occurs somewhere within the solid nutrient layer rather than within the cooling tubes. Third, by adjusting the flow of cooling fluid through the masking system, the thickness of the solid nutrient layer can be adjusted and is this way, the dimension of the growing zone 18 can be precisely adjusted.
The pulling system 13 includes apparatus for bringing a seed crystal 28 into contact with the growing zone 18 and then precisely drawing the seed crystal from the growing zone at a rate precisely equal to the optimum growing rate of the melt-seed crystal interface 29. The pulling system 13 also includes various oscillating devices and control devices well known in the art of pulling crystals.
FIG. 2 is a cross-sectional view of the system. It shows clearly the concept that the thickness of the solid nutrient layers 27 on each cooling tube 17 control the thickness dimension of the growing zone 18. As shown in FIG. 2, the dimensions of the growing zone 18 are normally such that the zone is a meniscus between the cooling rods.
The operation of the present invention will now be readily understood in view of the above description. The apparatus is first set up as generally shown in FIG. 1 without the seed crystal 28 in place. The flow of the cooling fluid 21 is set at a high value to protect the material of the cooling tubes 17. The cooling tubes are adjusted so that they define a growing area 18 slightly larger than desired in the final product. The crucible 14 is then filled with solid nutrient and the radio-frequency or induction-type heaters 16 are turned on. As the nutrient melts, it forms a solid layer 27 between the melt and the cooling tubes 17. The flow of the cooling fluid 21 is then adjusted by valves 23 and 24 to set the thickness of the solid nutrient layer 27 around the cooling tubes at a desired dimension. The seed crystal 28 is then lowered into the growing zone to form the growing interface 29 and the pulling system 13 is activated to draw the seed crystal from the growing zone as the growing takes place at the interface.
Although this technique can be used to grow crystals of various cross-sections depending on how the cooling tubes are arranged to form the growing zone 18, the cost effective shape is a cross-section which is long in the dimension parallel to the cooling tubes and very small in the dimension perpendicular to the cooling tubes. Thus, a sheet of crystalline material can be formed with a precisely controlled thickness.
Referring next to FIG. 3, which shows a modified form of the invention, the crystal growing system, indicated generally by the reference numeral 110, is shown as including a nutrient source 111 feeding particulate nutrient material to a masking system 112. The pulling system 113 allows the finished crystal to be withdrawn from the system. The crucible 114 is shown as having a complete enclosure and providing for a melt 115 between two heaters 116. Within the heaters are cooling tubes or passages 117 and between the heaters is a growing zone 118. Cooling fluid 121 passes through the passages 117 to regulate the temperature of the heater. The fluid originates in a fluid source 122, the flow of the passages being regulated by valves 123 and 124. The seed crystal 128 is formed below the growing zone 118.
A pressurized gas source 119 is connected to the interior of the crucible enclosure with a neutral gas, such as nitrogen. The heaters 116 consist of two electrodes formed of the same semi-conductor material as the crystal to be grown and they have spaced, parallel, cylindrical surfaces 125 and 126, defining a gap of the cross-sectional shape desirable in the finished crystal. The cooling passages 117 are closed to the surfaces 125 and 126 and in the preferred embodiment are concentric with them. The nutrient source 111 is shown as consisting of a feeder for introducing particulate into the interior of the crystal without loss of the gaseous atmosphere and includes a rotor 127 driven by an electric motor 129. The pulling system 113 includes a pair of seals 120 through which the formed crystal 128 can slide without loss of the atmosphere within the crucible. A control 130 is provided to control the electrical flow across the electrodes. The current originates in an electrical source 131 which, in the preferred embodiment, is 110 volts A/C 60 HZ. The control is connected to a rheostat 132 to control the heating and to the motor 129 to control the feed rate.
It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed. | System for formation of a mineral crystal having a regular cross-sectional shape, including a crucible, a mass of crystal nutrient melt in the crucible, and a cooling element which defines a growing zone on the surface of the nutrient melt. | 8 |
RELATED APPLICATIONS
This application claims priority, under 35 U.S.C. §102(3) as a Continuation-In-Part Application, to U.S. patent application, Apparatus and Method for Testing RAMBUS Drams, Ser. No. 09/454,808, filed in the United States on Dec. 3, 1999, now U.S. Pat. No. 6,530,045, issued Mar. 4, 2003.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to semiconductor wafer testing and more particularly to an apparatus and method for reducing the pin count necessary to test Rambus dynamic random access memory (RDRAM).
2. Description of the Related Technology
Rambus DRAM (RDRAM) is a general-purpose, high-performance, packet-oriented dynamic random-access memory (DRAM) device suitable for use in a broad range of applications, including computer memory, graphics, video, and other applications. FIG. 1 schematically illustrates an RDRAM device 10 interconnected with a central processing unit (CPU) 11 as part of a typical computer system. The RDRAM device 10 receives clock signals 12 , control logic signal 14 and address information 16 from the CPU 11 via a controller 20 . Data 17 is written to and read from the RDRAM 10 .
FIG. 2 is a block diagram illustrating one 144 Mbit RDRAM configuration in the normal mode. The RDRAM comprises two major blocks: a “core” block 18 comprising banks 22 , sense amps 24 and I/O gating 26 similar to those found in other types of DRAM devices, and a control logic block in normal mode 19 which permits an external controller 20 to access the core 18 . The RDRAM core 18 is internally configured as 32 banks 22 . Each bank 22 has 32,768 144-bit storage locations.
FIG. 3 is a diagram indicating that each of the banks 22 is organized as 512 rows 28 by 64 columns 30 by 144 bits 32 . The 144 bits 32 in each column 30 are serially multiplexed onto the RDRAM's I/O pins as eight 18-words 34 . The most significant bits 17 - 9 are communicated on I/O pins DQA < 8 : 0 >, and the least significant bits 8 - 0 are communicated on the I/O pins DBQ < 8 : 0 >. The nine bits on each set of pins are output or input on successive clock edges so that the bits in the eight words are transferred on eight clock edges.
The control logic block 19 in FIG. 2 receives the CMD, SCK, SIO 0 , and SIO 1 strobes that supply the RDRAM configuration information to the controller 10 , and that select the operating modes of the RDRAM device 10 . The CFM, CFMN, CTM and CTMN pins generate the internal clocks used to transmit read data, receive write data, and receive the row and column pins used to manage the transfer of data between the banks 22 and the sense amps 24 of the RDRAM 10 .
Address information 16 is passed to the RDRAM device 10 from the CPU 11 via eight RQ pins 36 illustrated in FIG. 4 . The RQ pins 36 are divided into two groups. Three ROW pins 38 are de-multiplexed into row packets 40 that manage the transfer of data between the banks 22 and the sense amps 24 . Five COL pins 42 are de-multiplexed into column packets 44 and manage the transfer of data between the data pins and the sense amps 24 of the RDRAM 10 . More detailed information on the operation of RDRAM can be found in Reference A, Direct RDRAM Preliminary Information, Document DL0059 Version 0.9 by Rambus Inc. which is incorporated herein by reference.
Semiconductor chips, such as an RDRAM device 10 , contain circuit elements formed in the semiconductor layers which make up the integrated circuits. FIGS. 5A and 5B illustrate a semiconductor chip with exposed bonding pads 46 made of metal, such as aluminum or the like that are formed as terminals of integrated circuits. In normal operation, the control signals 14 , the address signals 16 , and the data 17 are exchanged with the CPU 11 through connections at these bonding pads 46 .
In the manufacturing process, a large number of semiconductor chips, each having a predetermined circuit pattern, are formed on a semiconductor wafer 48 such as that shown in FIG. 6 . FIG. 6 illustrates the semiconductor wafer 48 prior to being diced into individual semiconductor chips. Although FIG. 6 only shows a relatively small number of semiconductor chips on the wafer, one skilled in the art will appreciate that many semiconductor chips can be cut from a single wafer. The semiconductor chips 10 are subjected to electrical characteristic tests while they are on the wafer 48 through the use of a testing apparatus, e.g., a wafer probe 50 having a plurality of pins 52 . Note that only the head of the wafer probe 50 is shown in FIG. 6 . Wafer probe testing is commonly used to quality sort individual semiconductor chips before they are diced from the wafer 48 . The primary goal of wafer probe testing is to identify and mark for easy discrimination defective chips early in the manufacturing process. Wafer testing significantly improves manufacturing efficiency and product quality by detecting defects at the earliest possible stages in the manufacturing and assembly process. In some circumstances, wafer probe testing provides information to enable certain defects to be corrected.
FIG. 7 shows a plurality of the conductive pins 52 of the wafer probe 50 of FIG. 6 . The pins have respective tip ends 54 positionally adjusted to align with the bonding pads 48 of the RDRAM device 10 to be tested. A wafer probe 50 has a limited number of pins 52 (e.g., 100 pins) available to supply the test signals to the RDRAM device 10 in the wafer 48 . The RDRAM devices 10 could be tested in their normal mode, but this would require in excess of 40 pins 52 on the wafer probe 50 to test each chip 10 . Others have recognized the benefits of creating a special test mode that enables a semiconductor chip such as the RDRAM device 10 to be tested with fewer pins. Therefore, one skilled in the art will recognize that it is not required to have a pin 52 for every bonding pad 48 on the chip 10 . However, prior testing methodology for RDRAM devices 10 requires at least 34 pins 52 on the wafer probe 50 to test each RDRAM device 10 . Consequently, the 100 pin wafer probe is restricted to test, at most, two semiconductor chips at one time. As a result, the production time and chip costs are negatively impacted by this limitation.
As set forth above, the prior art method of wafer testing RDRAM chips requires 34 pins 52 to test each RDRAM device 10 , of which 18 pins are address and data pins. Following this method, the first operation in selecting the address on the RDRAM core entails precharging the bank 22 . Precharging is necessary because adjacent banks 22 share the same sense amps 24 and cannot, therefore be simultaneously activated. Precharging a particular bank 22 deactivates the particular bank and prepares that bank 22 and the sense amps 24 for subsequent activation. For example, when the row 28 in the particular bank 22 is activated, the two adjacent sense amps 24 are connected to or associated with that bank 22 , and therefore are not available for use by the two adjacent banks. Precharging the bank 22 also automatically causes the two adjacent banks to be precharged, thereby ensuring that adjacent banks are not activated at the same time.
Selecting one of the 32 banks 22 to precharge requires five address bits to specify the bank address. These address bits are provided in a first control signal. The next operation in selecting an address is activating a row 28 in a selected bank using a second control signal. This operation requires nine address bits to select one of the 512 rows 28 , and five address bits to select one of the 32 banks 22 , for a total of 14 address bits. The next operation reads a column 30 in an open bank using a third control signal. This operation requires five bank bits. This operation also requires six column bits to select one of the 64 columns 30 .
Reducing the number of address bits required to specify the address location to be tested reduces the number of pin connections 52 required on the wafer probe 50 to test each individual RDRAM device 10 . Reducing the required number of pin connections 52 therefore allows more devices 10 to be tested at the same time, thus permitting an important reduction in production time and chip costs. As chip sizes continue to decrease, there is a corresponding increase in the number of chips on each semiconductor wafer to be tested. Therefore, the ability to test an increased number of devices at the same time grows in importance.
SUMMARY OF THE INVENTION
The invention comprises a method of testing computer memory devices, such as Rambus DRAM. The method requires fewer pin connections to test each chip on a semiconductor wafer than previously known methods. The test is performed on a semiconductor wafer using a wafer probe. The number of pins required is reduced by using a trailing edge of a precharge clock to latch the bank address, thus eliminating the need to perform this function on a later step. In combination with such use of the precharge clock's trailing edge, the number of pins required is further reduced by dividing the chip to be tested into a plurality of array cores and compressing the output data so that only one data pin per array core is required. By reducing the pin count, more DRAMs can be tested at the same time, thus reducing the overall test cost and time for testing a complete wafer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating a RDRAM device as part of a computer system.
FIG. 2 is a functional block diagram illustrating the RDRAM chip configuration in the normal mode.
FIG. 3 is a conceptual drawing illustrating the RDRAM bank configured in rows, columns, words, and bits in the normal mode.
FIG. 4 is a conceptual drawing illustrating RQ pins developing the address information of FIGS. 1 and 2 .
FIG. 5A is a top plan view of a RDRAM chip illustrating the bonding pads.
FIG. 5B is a side elevation of the RDRAM of FIG. 5 A.
FIG. 6 is a perspective view of a RDRAM semiconductor wafer comprising a plurality of chips with a wafer probe.
FIG. 7 is a top plan view of the bonding pads of a RDRAM chip aligned with the conductive pins which are connected to a wafer probe.
FIG. 8 is a functional block diagram illustrating the RDRAM chip configuration in the DFT mode.
FIGS. 9A and 9B are conceptual drawings, illustrating the RDRAM bank configured in rows, columns, words, and bits and being further divided so that the data from two rows can be compressed for 2X row compression and output compressed into a single DQ for DQ compression.
FIG. 10 is a block diagram illustrating the RDRAM core divided up into four quadrants with a single DQ output after DQ compression.
FIG. 11 is a timing diagram illustrating a typical write cycle in the DFT mode.
FIG. 12 is a timing diagram illustrating a typical read cycle in the DFT mode.
FIG. 13 is a timing diagram illustrating the compressed data output for a DQ in a window manner showing a fault detection.
DETAILED DESCRIPTION OF THE INVENTION
The RDRAM in accordance with the invention has two modes of operation: (1) a high speed packet mode for normal operation; and (2) a low speed asynchronous mode for testing, which bypasses the packetizing hardware, often called “design for test” circuits or DFT. This second mode, shown as a block diagram in FIG. 8 is realized by including DFT mode control logic 58 and data compression logic 59 in the RDRAM device 10 to facilitate testing. In one embodiment of the invention, in the DFT test mode, the RDRAM behaves similar to an asynchronous DRAM, although data is still input/output in bursts of eight.
As shown in FIG. 8 , the RDRAM comprises three major blocks: a “core” block 18 , the control logic block in DFT mode 58 and the Data Compression/Expansion Logic box 59 . As shown in FIGS. 9A and 9B , the core 18 is internally configured as 32 banks 22 organized at 512 rows 28 by 64 columns 30 by 144-bit storage locations. The 144 bits are multiplexed as eight 18-bit words. The core is further divided for testing purposes as will be discussed below.
The DFT control logic 58 receives a number of signals from the wafer probes 50 , including, TestBSENSE, TestPRECH, TestWRITE, TestCOLLAT, TestCLK_R/W, SIO 0 , SIO 1 , CMD, SCK, and Burn PRECH_EN. The Data Compression/Expansion Logic 59 compresses data so that only four data pins are required, as will be discussed below.
The pins required for the DFT mode of operation are a subset of the pins used in the normal mode of operation. Many of the functions of the normal mode pins are redefined (as discussed below) for the DFT mode. The mapping of the normal mode pins to the DFT mode function is illustrated below in Table 1.
TABLE 1
DFT Pin Mapping
Pin
DFT Function
SCK
SCK
CMD
CMD
SIO<1:0>
SIO<1:0>
CFM/CTM
TestClkR/W
RQ<0>
TestBSENSE
RQ<1>
TestPRECH
RQ<2>
TestWrite
RQ<3>
TestCOLLAT
DQB<2:0>
ADR<2:0>
DQA<3:0>
ADR<6:3>
DQB<3>
ADR<7>
DQB<6>
ADR<8>
DQB<8>
Burn PRECH_EN
DQA<5:4>
DQ<1:0>
DQB<5:4>
DQ<3:2>
CFMN/CTMN
VCC/2
VCMOS
VCMOS
To test a specific location in the core block 18 of the RDRAM device 10 , the location must be referenced by its bank address, row address, and column address. In the normal configuration of a 144 Mbit RDRAM device as illustrated in FIG. 3 , selecting the bank address of one of the 32 banks requires five address bits, selecting a row address of one of the 512 rows in a bank requires nine address bits, and selecting a column address of one of the 64 columns in a bank requires six address bits. In accordance with the present invention, the 144 Mbit RDRAM device is wafer tested using DQ compression and 2X row compression.
In a further embodiment, a 288 Mbit RDRAM device can be tested according to the invention as well. In the normal configuration of a 288 Mbit RDRAM device, the RDRAM core block 18 is internally configured as 32 banks 22 . Each bank 22 is organized as 512 rows 28 by 128 columns 30 by 144 bits 32 . Selecting the bank address of one of the 32 banks requires five address bits, selecting a row address of one of the 512 rows in a bank requires nine address bits, and selecting a column address of one of the 128 columns in a bank requires seven address bits. In accordance with the present invention, the 288 Mbit RDRAM device can be wafer tested using either DQ compression or DQ compression and 2X row compression.
In DQ compression, the RDRAM device 10 is divided into four quadrants, 60 A, 60 B, 60 C, and 60 D, as illustrated in FIG. 10 , with each quadrant corresponding to a respective 36 megabit array core 61 A, 61 B, 61 C, and 61 D. Each array core 61 A, 61 B, 61 C, and 61 D is an independent repair region. The lower two quadrants, 60 A and 60 B, comprise banks 0 - 15 . The upper two quadrants, 60 C and 60 D, comprise banks 16 - 31 . This division is based on physical design parameters of the RDRAM device 10 . The lower left quadrant 60 A comprises bits 9 - 17 of banks 0 - 15 . The lower right quadrant 60 B comprises bits 0 - 8 of banks 0 - 15 . The upper left quadrant 60 C comprises bits 9 - 17 of banks 16 - 31 . The upper right quadrant 60 D comprises bits 0 - 8 of banks 16 - 31 . As discussed below, for testing, only a single bit of data is transferred into and out of each quadrant 60 A, 60 B, 60 C, and 60 D. In particular, as will be discussed below, a data bit DQ 0 is used to test the upper left quadrant 60 C. A data bit DQ 1 is used to test the upper right quadrant 60 D. A data bit DQ 2 is used to test the lower left quadrant 60 A. A data bit DQ 3 is used to test the lower right quadrant 60 B. Therefore, only four data bits are required to test the entire memory. Note further that the upper banks ( 16 - 31 ) and the lower banks ( 0 - 15 ) have separate data connections in the DFT mode. Thus, the most significant bank bit that distinguishes the upper and lower sets of banks is not required, and the number of bank bits is reduced from five bits to four bits.
In one embodiment of the invention using DQ compression and 2X row compression, the 2X row compression further reduces the number of bank address bits required. In particular, the data from corresponding rows in two alternating banks (e.g., bank n with bank n+2 and bank n+16 with bank n+18) are combined as shown in FIGS. 9A and 9B so that the data are transferred to and from belt rows using a common DQ bit. This reduces the number of selectable banks in each quadrant from sixteen to eight. Thus, only three bank bits are required to select one of the eight banks in each quadrant.
The data from the two rows of the alternating banks are transferred (either written to the memory or read from the memory) one byte at a time, as in the normal mode. However, because only one data pin is available for each quadrant 60 A, 60 B, 60 C, and 60 D, the nine bits of data from each of the two rows (18 bits of data in all) in each quadrant are combined into a respective single bit (i.e., DQ 0 , DQ 1 , DQ 2 , or DQ 3 ). Thus, for each quadrant the data from a column in the two rows are output as a sequence of eight single data bits.
The compression of the data bits is performed by the data compression/expansion logic 59 . Each quadrant 60 A, 60 B, 60 C, and 60 D can have an associated data compression/expansion logic 59 A, 59 B, 59 C, and 59 D as illustrated in FIGS. 9A and 9B . Data are written to the memory by applying a data bit to each of the compressed data pins (i.e., to DQ 0 , DQ 1 , DQ 2 , DQ 3 ). On each clock edge the data compression/expansion logic 59 fans out the single data bit to the eighteen data locations addressed by the bank, row and column bits. Thus, the same data are written into all eighteen locations. Thereafter, when the memory locations are read to test the integrity of the memory, the data from the eighteen locations read during each clock edge are compared to determine if any location has a different data output. If the data are the same, the output on the DQ line has a first constant state (e.g., a logic one or a logic zero in accordance with the data written during the write operation) to indicate pass. If any bit of the eighteen locations is different, the data output on the DQ line is forced to have a transition to indicate a failure.
In one embodiment for testing a 288 Mbit RDRAM device, the result of the DQ compression and the 2X row compression is that the array cores 61 A, 61 B, 61 C and 61 D are configured as 8 banks by 512 rows by 128 columns by eight four-bit bytes. Therefore, only three bank select bits, nine row address bits, and seven column address bits are required to identify a particular location in the array core. This results in the ability to test each RDRAM device 10 using only nine pins on the wafer probe 50 for defining a specific address location. When the row is activated, nine row address bits identify one of the 512 rows. When a column in an open bank is read, the seven column bits identify the column in the bank to be written to or read from.
FIG. 11 is a timing diagram that illustrates a typical write cycle that is used to select the bank for row access and the bank for column access, row address, column address, and strobe in the data. FIG. 12 is a timing diagram that similarly illustrates a typical read cycle. In FIGS. 11 and 12 , address pins 64 , 68 , and 70 refer to subdivisions of the nine address pins used to identify a particular location in the array core. Address pins 64 represent Addr< 8 : 6 > (three address pins 8 , 7 and 6 ). Address pins 68 represent Addr< 5 : 1 > (five address pins 5 , 4 , 3 , 2 , and 1 ). Address pins 70 represent Addr< 0 > (one address pin 0 ).
In the write and read cycles depicted in FIGS. 11 and 12 , respectively, a precharge clock, TestPRECH 62 , is used to select the bank address. The leading edge of TestPRECH 62 is used to precharge the bank designated by the bank address present on the address pins 64 . Precharging the bank prepares the bank and the sense amps for activation. Since adjacent inner banks share the same sense amps, adjacent banks cannot be activated at the same time. Precharging any bank automatically causes adjacent banks to be precharged also, thereby ensuring that adjacent banks are not open at the same time. This happens in all modes of operation, not just the DFT mode.
On the falling edge of TestPRECH 62 , the bank corresponding to the bank address on the address pins 64 is latched. This latched bank address represents the bank that will be activated the next time TestBSENSE is presented. Multiple banks can be active at any one time. That is, banks previously activated and not subsequently deactivated by precharging remain active in addition to the newly activated bank. Precharging banks and latching banks are accomplished using different edges of the same TestPRECH signal 62 . Thus, the present invention eliminates the need to provide separate control signals for the precharge function and the latching function.
Next, a row address is selected using address pins and a row sense clock, TestBSENSE 66 . TestBSENSE 66 causes the selected row of the latched (i.e., active) bank to be sensed. The row address to be sensed is the address present on the address pins 64 , 68 and 70 at the falling edge of TestBSENSE 66 . Because there are 512 rows, nine address pins are required to select the row to be tested. Because the bank was latched using the other edge of the TestPRECH 62 , it is not required to select a bank in this operation. Thus, unlike other known methods, the bank select bits do not have to be applied at this time and only the nine address bits need to be applied.
Data are then either read from or written to the column in accordance with the address present on the address pins at the rising edge of a column latch clock, TestCOLLAT 72 . The row address of the bank to be opened is presented on the falling edge of TestBSENSE 66 . The address of the column to be accessed is presented on the rising edge of TestCOLLAT 72 . In one embodiment of the invention, if a new bank is to be opened, then the address of that bank must be the same as the bank of the column to be accessed. As a result, nine address bits are sufficient to provide the necessary address bits to identify any location in the array core.
In a further embodiment, the bank must be one of the banks that was active when TestBSENSE 66 was applied. A TestWrite clock 74 determines whether the operation performed at TestCOLLAT 72 time is a read or a write function. If TestWrite=1 at the rising edge of TestCOLLAT 72 , then the data present in a write buffer are written to the RDRAM core. If TestWrite=0 at the rising edge of TestCOLLAT 72 , then the data are read from the RDRAM core to a read buffer.
FIGS. 11 and 12 show a TestClkR/W clock 76 strobing data into the write buffer or out of the read buffer depending on the state of TestWrite 74 . If TestWrite=1, then data are input into the write buffer from the tester on sequential edges of TestClkR/W 76 , beginning with the first falling edge. Eight clock edges transfer data. It takes a total of six TestClkR/W 76 cycles to completely load the write buffer. Additional clock cycles will initiate another load sequence. A load sequence is not terminated until the exact number of clock cycles are provided. If TestWrite=0, then data are read from the read buffer to the external bus on each edge of TestClkR/W 76 , beginning with the second falling edge. Eight clock edges transfer the data. It takes a total of six TestClkR/W 76 cycles to completely empty the read buffer. The chip under test remains in the output mode until the data are read out of the read buffer. Any additional clock cycles initiates a new read sequence. Note that any transition on TestClkR/W 76 initiates a read or write sequence depending on the state of TestWrite 74 .
FIG. 13 is a timing diagram that illustrates the compressed data being output in a window manner when reading the compressed DQs. If the expected data is a “0”, then the DQ will be low during the entire window. A failure is indicated if the wrong data is present, or if a data transition is detected during the window. If the expected data is “1”, then the DQ should remain high throughout the window.
If a fault is indicated, it is not necessary to determine which bit failed, it is sufficient to localize the fault to a row. The tester has the capability to reconfigure the chip so that a spare row is used to replace the row with the fault. The technology for such reconfiguration is well known in the field.
Note that by reducing the required address bits to three and by using both edges of the TestPRECH control signal, the maximum number of address bits required is nine, which with the addition of the four data bits, totals thirteen. This is significantly fewer than the eighteen data and address bits used in other known test methods.
Although specific implementations and operation of the invention have been described above with reference to specific embodiments, the invention may be embodied in other forms without departing from the spirit or central characteristics of the invention. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning of equivalency of the claims are to be embraced within their scope. | An apparatus and a method are disclosed for reducing the pin driver count required for testing computer memory devices, specifically Rambus DRAM, while a die is on a semiconductor wafer. By reducing the pin count, more DRAMs can be tested at the same time, thereby reducing test cost and time. One preferred embodiment utilizes a trailing edge of a precharge clock to select a new active bank address, so that the address line required to select a new active address does not have to be accessed at the same time as the row lines. | 6 |
FIELD OF THE INVENTION
The present invention relates generally to fabrics, and more particularly to electric heating fabrics such as warming blankets.
BACKGROUND OF THE INVENTION
In general, a warming blanket, also called an “electric blanket,” or an “electric heating blanket,” is a blanket or another fabric material having an insulated electric heating element. The heating element is typically provided as one or more metallic wires threaded in a serpentine pattern throughout the blanket or arranged as a collection of parallel wires. The shape and size of the metallic wires varies, and in some cases the wires can actually be small metallic threads.
A warming blanket is typically plugged into a power outlet so that power may be supplied to the heating element, causing the production of heat. In this manner, the warming blanket may be a warm, comfortable cover used to warm a bed or may be wrapped around an individual as a heated, comfortable throw blanket, for example. A separate category of electrically heated bedding includes mattress pads. Mattress pads are typically placed under the warming blanket are utilized to warm the bed before use or to provide comfortable heat in the event the user does not wish to be covered with a fabric.
Contemporary warming blankets usually include a user control, such as a dial, that permits a user to set the amount of heat output of the blanket. This feature allows the consumer to set the blanket to a setting that offers the desired amount of heat for a particular temperature and in accordance with the comfort level of the individual.
SUMMARY OF THE INVENTION
The present invention provides a warming blanket having a temperature sensing wire threaded through the warming blanket to sense the temperature of the warming blanket. The warming blanket may alternatively be any type of warming fabric, such as a heated throw, mattress pad, heating pad, car seat heater, as examples. In accordance with one aspect of the present invention, the temperature sensor is a positive temperature coefficient (PTC) device that is threaded throughout the blanket fabric.
In accordance with one embodiment of the present invention, the temperature sensing wire runs transverse to the heating wires in the warming blanket. This feature permits the temperature sensing wire to measure an average blanket temperature, because the temperature sensing elements cross portions of the blanket that have heating wires, and portions that do not have heating wires.
In accordance with another embodiment of the present invention, the heating element is supplied as a pair of buss wires extending along opposite sides of the warming blanket and having a number of heating wires extending therebetween. In this embodiment, the temperature sensing elements may run either parallel to or transverse to the heating elements.
Information from temperature changes in the temperature sensing element of the present invention may be provided to a microcomputer so that the microcomputer may adjust the heat output of the heating element in the warming blanket. In this manner, the temperature sensing wire and the microcomputer behave similar to a thermostat. If PTC is used as the heat-sensing material for the temperature sensing element, in one example a reference voltage (e.g., 5 volts) is applied to a length of the PTC element. Because resistance of the PTC material changes with changes in temperature, the current flowing through the PTC sensing element will increase or decrease as a result of temperature changes. The current change may be measured, and correlates with temperature changes in the PTC element, either locally or over long lengths of the sensing element.
In one embodiment of the invention, the end of the PTC sensing element opposite the end where voltage is applied is connected to a fixed resistor, which in turn is connected to ground. A voltage signal is tapped from a point between the PTC sensing element and the fixed resistor, and information about the voltage is sent to the microcomputer. As the temperature of the PTC sensing element increases, its resistance increases and in turn the voltage signal to the microcomputer decreases. The microcomputer may then, for example, decrease the amount of power supplied to the heating elements, or may cut the power to the heating elements altogether.
In accordance with one aspect of the present invention, the PTC sensing element is formed by extruding a PTC compound onto a nonmetallic core or carrier. As an example, the nonmetallic carrier is a polymeric material, such as a polyester core.
Because the core of the PTC temperature sensing wire is nonmetallic, the sensing element is flexible and has a thin profile. In addition, the sensing element is lightweight, and thus does not add significant bulk to a warming blanket. Moreover, since the temperature sensing elements cover the warming blanket, it is possible to detect localized overheating in the warming blanket, no matter where the localized heating may occur in the blanket.
The fixed resistor requires very little additional PC board area and may be added to existing warming blanket controls with little effort or cost. As such, adding the resistor and microcomputer to conventional warming blanket controls requires very little modification.
Other advantages will become apparent from the following detailed description when taken in conjunction with the drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram representation of a warming blanket incorporating the present invention;
FIG. 2 is a block diagram representation showing detail of controls for the warming blanket of FIG. 1;
FIG. 3 is a diagrammatic representation of an arrangement for electric heating element wires and temperature sensor elements for a warming blanket in accordance with one aspect of the present invention;
FIG. 4 is a diagrammatic representation of a another arrangement for electric heating element wires and temperature sensor elements for an alternative embodiment of a warming blanket in accordance with another aspect of the present invention;
FIG. 5 is a diagrammatic representation of yet another arrangement for electric heating element wires and temperature sensor elements for another embodiment of a warming blanket in accordance with another aspect of the present invention;
FIG. 6 is a flow diagram generally representing steps of operation of the controls of the warming blanket of FIG. 1 in accordance with one aspect of the present invention; and
FIG. 7 is a cross section of a temperature sensing element formed in accordance with one aspect of the present invention.
DETAILED DESCRIPTION
In the following description, various aspects of the present invention will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without the specific details. Furthermore, well-known features may be omitted or simplified in order to not obscure the present invention.
Referring now to the drawings, in which like reference numerals represent like parts throughout the several views, FIG. 1 shows a warming blanket 20 incorporating the present invention. The warming blanket 20 includes a blanket 22 , made of a natural or synthetic material, such as a polyester/acrylic blend, or another suitable blanket or blend of material. Although a blanket is described with respect to the embodiment shown, the blanket 22 may alternatively be a throw or mattress pad, heating pad, a heated car seat or any other type of fabric that is to be heated.
An electric heating element 24 is included in the blanket 22 , the construction and operation of which is known in the art. In general, a heating element is any device or structure that may produce heat using electrical power. For example, the heating element may be formed of resistive wires. A reference DC or AC voltage is applied across the resistive wires to cause them to increase in temperature. Although the drawings show DC voltages, an AC voltage may be used depending upon the design of the control.
A temperature sensing element 28 is also included in the warming blanket 20 . In general, as is further described below, the temperature sensing element 28 is a device whose resistance varies with temperature. While the warming blanket 20 is described as having one temperature sensing element, an embodiment in accordance with the present invention may include two or more temperature sensing elements.
As an example, the temperature sensing element may be a wire extruded from positive temperature coefficient (PTC) material, such as a conductive, plastic, PTC compound. Example PTC temperature sensing elements are further discussed below.
The warming blanket 20 includes controls 26 connected to the temperature sensing element 28 and the electric heating element 24 . A first power cord 30 leads from the controls 26 to the electric heating element 24 , and a second power cord 32 leads to the temperature sensing element 28 . A power source 34 is connected to the controls 26 , and may be provided, for example, via a DC converter connected to an AC outlet, or via another DC source.
One or more user controls 36 , 38 are provided, and are attached to the controls 26 via wires 40 , 42 , although a wireless connection may be used. The user controls 36 , 38 may be mounted on the outside of a box for the controls, for example, and may be any type of configuration that permits a user to input a desired setting for the warming blanket 20 , e.g., dials, slide bars, push-button indexing units with digital or LED displays, and so forth. In the embodiment shown in FIG. 1, two user controls 36 , 38 are shown, which may be used, for example, on a blanket having two different heating zones. However, if a single zone blanket is used, then only one user control (e.g., 36 ) is needed, along with the corresponding wire (e.g., 40 ), or wireless connection, if relevant. Various other combinations may be configured by a person of skill in the art.
Briefly described, in accordance with one aspect of the present invention, the controls 26 and the temperature sensing element 28 are configured such that the temperature sensing element 28 supplies temperature information regarding the temperature of the blanket 22 to the controls 26 , and the controls adjust the heat output of the blanket 22 according to the temperature information.
FIG. 2 shows an embodiment of a warming blanket 120 utilizing a single user control 136 with a blanket 122 . The controls 126 for the shown embodiment are attached to a DC power source 134 and include a heat output component 50 , a look-up table or algorithm 52 , and a microcomputer 53 . The microcomputer 53 is a standard control (i.e., a device or mechanism used to regulate or guide the operation of a machine, apparatus, or system) or other device that can execute computer-executable instructions, such as program modules. Generally, program modules include routines, programs, objects, components, data structures and the like that perform particular tasks or implement particular abstract data types.
The temperature sensing element 28 is attached at one end to a positive terminal of the power source 134 . The opposite end of the temperature sensing element 28 is attached to a fixed series resistor 56 . A wire 58 connects to the junction 60 of the resistor 56 and the temperature sensing element 28 , and an A/D converter 62 is connected to the wire 58 . The A/D converter 62 , in turn, is arranged to send signals to the microcomputer 53 , either through a hard-wired connection or via a wireless transmission. Alternatively, the A/D converter 62 may be a contained within the microcomputer 53 in a manner known in the art.
The fixed series resistor 56 may be, for example, a 100K ohm resistor. The A/D converter 62 is configured to convert an analog voltage reading from the juncture 60 to a digital value representing the voltage at the juncture. Because the temperature sensing element's resistance varies with temperature, the voltage at the juncture 60 also varies with temperature. As further described below, the change in voltage information may be used to adjust the heat output of the electric heating element 24 in accordance with temperature changes in the blanket 122 .
In accordance with one aspect of the present invention, the digital information generated by the A/D converter 62 is used to represent temperature information. The digital voltage information changes with changes in temperature, because, as described above, the resistance of the temperature sensing element 28 varies with changes in the temperature of the blanket 22 . The digital voltage information may therefore be used to represent the temperature of the blanket 22 . This digital voltage information is used by the microcomputer 53 to determine the amount of adjustment to the heat output of the heating element 24 that is needed to offset variations in temperature of the blanket.
The microcomputer 53 , the A/D converter 62 , and the resistor 56 may be mounted on a conventional PC board, which in turn may be mounted in a control box for the warming blanket 120 . As such, the components used in conjunction with the temperature sensing element 28 use little space and may be added to the controls for conventional warming blankets with very little modification.
The temperature sensing element 28 may be arranged relative to the blanket 22 and the electric heating element 24 in a variety of different ways. However, preferably the temperature sensing element 28 covers a large portion of the blanket so that local overheating conditions may be sensed. In one embodiment of the present invention shown in FIG. 3, the electric heating element 24 forms a sinusoidal path, with the elongate portions of the path arranged parallel to one another and aligned in a particular direction (e.g., from the head to the foot of the blanket 22 ). The electric heating element 24 is connected to a power source 210 , and the wattage supplied by the power source is controlled by the heat output component 50 , which in turn is set by the microcomputer 53 .
In the embodiment shown in FIG. 3, the temperature sensing element 28 also loops back and forth across the blanket 22 in a sinusoidal pattern, with elongate portions of the element arranged parallel to one another and aligned transverse to the electric heating element 24 (e.g., from the side edge to side edge of the blanket 22 ). In the embodiment shown, the temperature sensing element 28 is aligned perpendicular to the electric heating element 24 , but the temperature sensing element 28 may be otherwise transverse to the electric heating element (e.g., aligned at an acute angle to the electric heating element). A power source 212 applies a voltage across the temperature sensing element 28 , such as 5 volts DC, and, as described above, the opposite end of the PTC sensor is connected to a resistor 56 (not shown in FIG. 3 ).
The embodiment shown in FIG. 3 is particularly advantageous in that the temperature sensing element 28 covers most of the blanket. Moreover, because the temperature sensing element 28 is arranged transversely to the electric heating element 24 , it may be used to sense various areas of the blanket 22 relative to the electric heating element 24 . For example, some portions of the temperature sensing element 28 run across the electric heating element 24 , and others are spaced from the electric heating element. This configuration thus gives an advantage in that it permits the temperature sensing element 28 to represent an average temperature of the blanket 22 .
Two more embodiments are shown in FIGS. 4 and 5. For each of these embodiments, a pair of bus wires 302 , 304 (FIG. 4 ), or 402 , 404 (FIG. 5) are connected to a power source 310 (FIG. 4) or 410 (FIG. 5 ). Heat element wires 324 or 424 extend between the two bus wires 302 , 304 or 402 , 404 , and extend parallel to one another. In the embodiment shown in FIG. 4, the temperature sensing element 328 extends transversely across the heat element wires 324 , and in FIG. 5 the temperature sensing element 428 extends parallel to the heating element wires 424 . Both embodiments provide the benefit of temperature sensing of most of the blanket, and the former provides the temperature sensing element aligned transversely with the heating element wires, the benefit of which is described above.
FIG. 6 shows a general overview of operation of the temperature compensation controls of the warming blanket 20 in accordance with one aspect of the present invention. For ease of understanding, the flow process is described as shown in FIG. 6 . It can be understood that the steps shown may be combined, performed in different orders, or one or more of the steps may be skipped and the process may still fall under the present invention as defined in the claims below.
Beginning at step 600 , a user enters a desired setting (e.g., via the user control 36 ). The setting represents a comfort level chosen by the user, and is stored in the microcomputer 53 . As an example, the user control 36 may include settings 1 to 10, with 10 being the warmest setting, and 1 being the least warm. These settings represent the heat setting of the warming blanket, and the user's selection determines the amount of power supplied to the electric heating element 24 , and therefore the temperature of the blanket 22 . That is, the amount of power that is supplied to the heating element 24 determines the heat output of the warming blanket 20 .
As one example, the settings may represent the amount of time (the “duty cycle”) that power is supplied to the electric heating element 24 during a fixed time period, such as 90 seconds. For a setting of 10, the time that power is supplied to the heating elements during the time period is longer than a setting of 9, 9 is longer than 8, and so forth. As one example, at the setting 10, the power may be supplied to the blanket for the entire time period. For a low setting, such as 1, the power may be supplied for only 10% (i.e., in the example above, 9 seconds) of the duty cycle. The remaining settings may increase the duty cycle linearly as the setting increases (e.g., 20% at 2, 30% at 3, and so forth). The microcomputer 53 may be programmed by a programmer of skill in the art to provide the heat output settings and other functions described herein.
Operating a warming blanket at different heat output settings is known, and other ways of modifying the power to the heating elements may be used, and the above is given as an example only. For example, the amount of power cycled to the heating element may be reduced, instead of the time the power is supplied to the heating element. In addition, more than one heating element or alternate arrangements for one or more heating elements may be used, and lower settings may use a first heating element, intermediate settings the second, and higher settings a combination of the two.
In any event, at step 602 , the temperature of the blanket 22 is sensed by the temperature sensing element 28 . If desired, power may be supplied intermittently to the temperature sensing element 28 to provide a voltage reading at the juncture 60 so that temperature readings may be provided at intervals. Alternatively, voltage (and therefore temperature) may be sensed constantly, by constantly supplying power to the temperature sensing element 28 during operation so that as long as the warming blanket 20 is operating, a voltage is supplied to the juncture 60 . If necessary, the temperature information is converted to digital in step 604 (e.g., by the A/D converter 62 ).
At step 606 , a determination is made whether the temperature is normal. That is, based upon the temperature data (i.e., in the example given, the voltage reading) provided by the temperature sensing element 28 , the microcomputer determines whether the temperature falls within a normal range for the selected user setting, and, based upon that determination, decides whether an adjustment needs to be made to the heat output of the blanket 22 to compensate for the temperature at the time of the sensing the temperature. If desired, temperature readings may be taken only after the blanket is expected to reach normal operating temperatures (e.g., beginning 5 minutes after the warming blanket is turned on).
If PTC material is used for the temperature sensing element 28 , then the voltage at the juncture 60 will decrease as the temperature increases. The allowed normal temperature may then be, for example, a minimum voltage for the juncture 60 . The minimum voltage reading for a particular blanket setting may be determined by empirical data, and may be stored as data in a lookup table 52 (FIG. 2) or as an algorithm.
If the temperature is normal, i.e., falls within the normal range, then step 606 branches to step 608 , where the heat output of the blanket is set to the normal (i.e., non-temperature adjusted) output that corresponds to the user's setting. As one example, the user may have set the user control 36 to the setting “5,” and the temperature of the blanket is 70 degrees, which for this example is within the normal temperature range of the blanket 22 at that setting. As such, using the example of operation of the controls of the warming blanket 20 described above, the heat output of the warming blanket is set to the normal setting for a “5,” wherein power is cycled to the blanket 50% of the time. Such instructions are sent by the microcomputer 53 to the heat output component 50 , which performs the heat output functions of the microcomputer's instructions.
If the temperature is not normal, i.e., falls outside the normal range, then step 606 branches to steps 610 and 612 , where the heat output of the blanket is adjusted to account for the amount the temperature is varied from normal. As an example, beginning at step 610 , an adjustment factor is calculated by the microcomputer 53 for the heat output of the warming blanket 22 . The adjustment factor may use one of many mechanisms used by the microcomputer 53 to calculate an appropriate adjustment to the heat output. The adjustment factor may, for example, be stored in a look-up table 52 by the microcomputer 53 using the voltage values from the A/D converter 62 .
As one example, as a result of an abnormal low voltage (i.e., high temperature) reading, the microcomputer 53 may adjust the power output downward to the blankets lowest setting. As another example, the microcomputer 53 may cut power to the electric heating element 24 . In still another example, the microcomputer 53 may adjust the wattage supplied to the electric heating element 24 based upon exactly how low the temperature (i.e., voltage reading) is below normal. Using the example given above, if the user has set the control to “5,” and the temperature of the blanket 22 has risen to cause the voltage reading to be slightly below normal, the microcomputer 53 may adjust the power supplied to the electric heating element 24 slightly downward (for example, to cycle 40% of the time instead of 50%). The adjustment downward may be increased as the voltage drops even more.
The amount that the output to the electric heating element 24 is adjusted may be determined empirically, and may be stored as an appropriate algorithm so that the microcomputer 53 may calculate the appropriate adjustment on the fly, or the adjustment values may be stored and accessed via a look-up table (e.g., by comparing the voltage values from the A/D converter 62 and the users settings to ranges of values stored in the lookup table, and adjusting according to the difference between normal values and the measured value). In accordance with one aspect of the present invention, when the user sets the user control 136 to the lowest setting, and the voltage drops below the normal range for that setting, the adjustment factor does not adjust the heat output downward, but instead cuts all power to the heating element. Power may be restored when the voltage is restored above the minimum value.
There are a number of different situations that may cause the temperature sensed by the temperature sensing element 28 to be higher, and therefore the voltage to drop. For example, the blanket 22 may be folded over too many times, causing a local overheating. Such a situation would cause the temperature to rise locally. However, because the temperature sensing element 28 extends through most of the blanket, the local rise in temperature would cause a corresponding rise in the resistance of the temperature sensing element at that location, resulting in a lower voltage reading. As another example, if too much bedding is piled onto the blanket 22 , heat dissipation may be limited, and a large portion of the blanket temperature may rise. In this example, the voltage reading would also drop, because the temperature of the temperature sensing element 28 would rise throughout the blanket. Because the temperature rises over much of the blanket in the second example, the temperature may not have to rise as much for the voltage to drop below “normal.”
At step 612 , the heat output is adjusted according to the adjustment factor by lowering the heat output according to the algorithm or information in the lookup table. Using the example described above, if the user sets the user control 36 to the setting “5” and the voltage reading for the blanket at that temperature corresponds to adjusting power supply to the blanket from a 50% to a 40% duty cycle, the heat output component 50 would therefore operate the blanket 122 so that power is supplied to the heating element 24 for 40% of the time. Thus, the microcomputer 53 may be programmed to cause the blanket 22 to operate at a lower heat output at the higher temperatures to provide less warming. This lower heat output causes the blanket to remain at a comfortable temperature for the user.
Adjusting the heat output to compensate for temperatures is preferably invisible to a user for the case where a large portion of the blanket is overheated. The blanket remains at the same temperature, but with less power supplied to the heating element 24 . In the case of local hot spots, however, the blanket temperature may have to drop to an uncomfortably low level or may even be turned off to avoid overheating. By doing so, the blanket temperature may be warning the user that excessive folding or unsafe conditions exist, so that the user may rearrange the blanket or adjust the blanket as necessary. If desired, an alarm may sound, the warming blanket 20 may be shut off, or the microcomputer 53 may otherwise handle an overheating situation.
After heat output is set by the microcomputer 53 (either at step 608 or step 612 ), then the process branches to step 614 , where a determination is made whether it is time to check the temperature again. If so, the process branches back to step 602 , where the temperature is sensed again. In this manner, the temperature compensation features of the present invention may be used in real time, so that adjustments may be made to heat output as the temperature changes. Additional temperature sensings may be made in set intervals, or by firing of events, in manners known in the art.
In accordance with one aspect of the present invention, as shown in FIG. 7, to form a temperature sensing element 728 , a PTC compound 700 is extruded onto a nonmetallic core 702 . By being nonmetallic, the core 702 is more flexible, and the entire PTC sensor 728 may be extruded in a thinner profile than can be produced with a metal core. The PTC temperature sensing element 728 is lighter than would be the case if the PTC material was extruded onto a metallic core, and the core 702 of the PTC temperature sensing element does not have to be insulated from the PTC compound 700 . The core material preferably is flexible and has sufficient tensile strength to not be broken within the blanket 22 . As one example, the core 702 may be a polymeric material, such as a yarn made from polyester, nylon, polyethylene, polypropylene, cotton, polyacrylic/cotton blends, etc. as examples. The polymeric yarn may optionally be coated with an electro-conductive adhesive or coating such as Electrodag 154 from Acheson Colloids. In addition, an optional insulating layer 706 may be added on the outer surface of the PTC compound.
In a more specific embodiment, the core 702 is a 1100 to 1200 denier polyester yarn that is extruded with a carbon black loaded polyolefinic PTC compound. It should be recognized that other suitable semi-crystalline polymers in combination with carbon black may also be suitable for temperature sensing means. These include blends of polyolefinic materials with amorphous polymers as well as homopolymers of polytetrafluroethylene and copolymers of vinylidene fluoride. The PTC compound may include 10-55% carbon black by weight of the total polymeric matrix to modify the electrical resistance. An electro-conductive adhesive is applied to the outer surface of the yarn before applying the PTC compound.
In one embodiment, the temperature sensing element has a resistance of approximately 200,000-575,000 ohms/100 feet at 75 degrees Fahrenheit, a higher resistance at higher temperatures (e.g., 240,000-725,000 ohms/100 feet at 90 degrees Fahrenheit), and a much higher resistance at higher temperatures (e.g., 360,000 ohms-1,200,000 ohms/100 ft. at 104 degrees Fahrenheit). (Above values are listed for example purposes only and may not represent the full range of the temperature sensing element's capabilities.) While the resistance of the temperature sensing element typically does not vary linearly with changes in temperature, its variation is predictable.
The present invention provides a warming blanket 20 that is capable of altering heat output to compensate for changes in the temperature of the blanket. The result is a warming blanket that provides safety from local hot spots. In addition, the warming blanket 20 adjusts accordingly to avoid overheating of an entire blanket, so that the blanket feels approximately the same warmth at the same setting regardless of a possible blanket overheating situation.
Many variations are possible. For example, as described above, the microcomputer 53 may use different ways of setting the amount of heat output. Although a preferred embodiment is described, many subsets of the components in the preferred embodiment may be used without the other components. For example, a warming blanket may utilize the temperature sensing and compensation components of the present invention, but not have user controls. In such an embodiment, a user does not have the option to change settings for the blanket (e.g., a single setting is fixed), but the heat output changes with changes in temperature. Moreover, although the various components are shown and described herein as separate components because of certain benefits resulting from separated functionality, it can be readily appreciated that some or all of the components may be combined into more complex components, and/or may be separated even further into additional components. As one example, more than one microcomputer may be used for the various functions described herein. However, that being said, one of the salient features of this invention is the fact that the microcomputer 53 and the resistor 56 may be incorporated in a printed circuit board with conventional controls for a warming blanket, thus minimizing additional costs and space needed for controls.
Other variations are within the spirit of the present invention. Thus, while the invention is susceptible to various modifications and alternative constructions, a certain illustrated embodiment thereof is shown in the drawings and has been described above in detail. It should be understood, however, that there is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims. | A warming blanket having a temperature sensing element for sensing the temperature of the warming blanket. The temperature sensor may be a positive temperature coefficient (PTC) element that is threaded throughout the blanket. In one embodiment, the temperature sensing element runs perpendicular or transverse to the heating wires in the warming blanket, permitting the temperature sensing element to measure an average blanket temperature. In another embodiment, the heating element is supplied as a pair of buss wires extending along opposite sides of the warming blanket and having a number of heating wires extending therebetween. In this embodiment, the temperature sensing elements may run either parallel to or transverse to the heating elements. Temperature changes/signals in the temperature sensing element are sent to a microprocessor, which in turn changes the wattage of the heating elements to prevent overheating of the warming blanket. | 7 |
BACKGROUND
An aircraft, such as a rotorcraft, may be used to transport cargo or a payload to a destination. Slung load cargo may often contain sensitive equipment or may be subject to a maximum drop rate or impact force at the time of drop off. The cargo, or equipment contained therein, might not withstand excessive impact associated with gravitational forces. In autonomous cargo applications, such as in unmanned aerial vehicle (UAV) applications, the cargo is delivered and dropped autonomously by a UAV vertical takeoff and landing (VTOL) platform. In such a case, the UAV needs to sense the event of the cargo making contact with the ground in order to perform a safe and controlled detachment operation with respect to the cargo.
Management of these transitions has traditionally been approached by additional sling load sensors, camera optical aids, and other sensors. These solutions entail higher cost and multiple points of failure. Soft-weight-on-wheels algorithms have been suggested, however, such algorithms do not apply to slung load situations.
BRIEF SUMMARY
An embodiment is directed to a method comprising: obtaining data associated with at least one aircraft flight parameter when an aircraft is being operated in flight; processing the data to determine that the at least one aircraft flight parameter indicates a change in value in an amount greater than a threshold; and decoupling a load from the aircraft based on determining that the at least one aircraft flight parameter indicates the change in value in the amount greater than the threshold.
An embodiment is directed to an apparatus comprising: at least one processor; and memory having instructions stored thereon that, when executed by the at least one processor, cause the apparatus to: obtain data associated with at least one aircraft flight parameter when an aircraft is being operated in flight; process the data to determine that the at least one aircraft flight parameter indicates a change in value in an amount greater than a threshold; and cause a load to be decoupled from the aircraft based on determining that the at least one aircraft flight parameter indicates the change in value in the amount greater than the threshold.
An embodiment is directed to an aircraft comprising: a plurality of sensors configured to provide data pertaining to collective input, engine power, and shaft torque; and a control computer configured to: process the data to determine that at a weighted combination of the collective input, engine power, and shaft torque indicates a step change in value in an amount greater than a threshold magnitude as a function of time during flight; and cause a load to be decoupled from the aircraft based at least in part on determining that the weighted combination of the collective input, engine power, and shaft torque indicates the step change in value.
Additional embodiments are described below.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements.
FIG. 1A is a general perspective side view of an exemplary rotary wing aircraft;
FIG. 1B is a schematic block diagram illustrating an exemplary computing system;
FIG. 2 is a block diagram of an exemplary system environment;
FIG. 3 is a block diagram of an exemplary system environment; and
FIG. 4 illustrates a flow chart of an exemplary method.
DETAILED DESCRIPTION
It is noted that various connections are set forth between elements in the following description and in the drawings (the contents of which are included in this disclosure by way of reference). It is noted that these connections in general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. In this respect, a coupling between entities may refer to either a direct or an indirect connection.
Exemplary embodiments of apparatuses, systems, and methods are described for detecting a load touchdown event. Detection of a load touchdown event may enable a safe transition to a stable load-detachment operation, wherein the load-detachment operation may be based on one or more autonomous or manual operations. Detection of a load touchdown event may occur without requiring the inclusion of additional or dedicated sensors. Existing flight control computer (FCC) parameters may be monitored to detect a touchdown event. Embodiments of the disclosure may provide for autonomous drop-off of cargo without a need for ground personnel to direct the aircraft descent till the touchdown event occurs.
FIG. 1A illustrates an exemplary vertical takeoff and landing (VTOL) rotary wing aircraft 10 . The aircraft 10 is shown as having a dual, counter-rotating main rotor system 12 , which rotates about a rotating main rotor shaft 14 U, and a counter-rotating main rotor shaft 14 L, both about an axis of rotation 16 . Other types of configurations may be used in some embodiments, such as a single rotor system 12 .
The aircraft 10 includes an airframe 18 which supports the main rotor system 12 as well as an optional translational thrust system 24 which provides translational thrust during high speed forward flight, generally parallel to an aircraft longitudinal axis 26 .
A main gearbox 28 located above the aircraft cabin drives the rotor system 12 . The translational thrust system 24 may be driven by the same main gearbox 28 which drives the rotor system 12 . The main gearbox 28 is driven by one or more engines 30 . As shown, the main gearbox 28 may be interposed between the engines 30 , the rotor system 12 , and the translational thrust system 24 .
The aircraft may be configured to deliver a load or payload, such as cargo 20 . The cargo 20 may be coupled to the aircraft 10 via a sling 22 . When touchdown of the cargo 20 has occurred, or is imminent within a threshold distance of the ground or an object, the cargo 20 may be decoupled or detached from the sling 22 .
Although a particular counter-rotating, coaxial rotor system aircraft configuration is illustrated in the embodiment of FIG. 1A , other rotor systems and other aircraft types such as tilt-wing and tilt-rotor aircrafts may benefit from the present disclosure.
Referring to FIG. 1B , an exemplary computing system 100 is shown. Computing system 100 may be part of a flight control system of the aircraft 10 . The system 100 is shown as including a memory 102 . The memory 102 may store executable instructions. The executable instructions may be stored or organized in any manner and at any level of abstraction, such as in connection with one or more applications, processes, routines, procedures, methods, etc. As an example, at least a portion of the instructions are shown in FIG. 1B as being associated with a first program 104 a and a second program 104 b.
The instructions stored in the memory 102 may be executed by one or more processors, such as a processor 106 . The processor 106 may be coupled to one or more input/output (I/O) devices 108 . In some embodiments, the I/O device(s) 108 may include one or more of a keyboard or keypad, a touchscreen or touch panel, a display screen, a microphone, a speaker, a mouse, a button, a remote control, a control stick, a joystick, a printer, a telephone or mobile device (e.g., a smartphone), a sensor, etc. The I/O device(s) 108 may be configured to provide an interface to allow a user to interact with the system 100 .
As shown, the processor 106 may be coupled to a number ‘n’ of databases, 110 - 1 , 110 - 2 , . . . 110 - n . The databases 110 may be used to store data, such as data obtained from one or more sensors (e.g., accelerometers). In some embodiments, the data may pertain to an aircraft's measured altitude and sink rate.
The system 100 is illustrative. In some embodiments, one or more of the entities may be optional. In some embodiments, additional entities not shown may be included. In some embodiments, the entities may be arranged or organized in a manner different from what is shown in FIG. 1B . For example, in some embodiments, the memory 102 may be coupled to or combined with one or more of the databases 110 .
Embodiments of the disclosure may be used in connection with a mission phase when a VTOL aircraft is in a controlled descent to drop or deposit slung-load cargo on the ground. Referring to FIG. 2 , a block diagram of a system 200 in accordance with one or more embodiments is shown. The system 200 may be used to detect a touchdown event and command a decoupling or detachment of a payload.
The system 200 includes a trigger device 202 and a detection device 204 . The detection device 204 may monitor various parameters associated with an aircraft (e.g., a helicopter), such as collective input, engine power, and shaft torque, to detect the event or instances when the payload contacts the ground. The collective input, engine power, and shaft torque may demonstrate a step drop or change in value in the event of touchdown when an aircraft is being operated under controlled descent for vertical velocity or altitude. The step drop in value may be observed in an event another heavy payload—such as fuel tanks, heavy equipment, or several onboard personnel—departs the aircraft. In lieu of the use of the trigger device 202 , these events may also be detected if the detection device 204 is enabled. In this regard, the trigger device 202 may be configured to signal or enable the detection device 204 in only particular instances or under specified conditions.
The step drop in value described above may occur because the aircraft may require less power and torque to maintain constant vertical velocity or altitude at lower gross weight. In case of additional sensors that provide load position and location information, such as load force sensors, cameras, a laser-based sensor, etc., these sensors can be included in the detection device 204 to augment the detection.
The trigger device 202 may accept input from altitude or pressure sensors that indicate a location of the aircraft above ground with respect to sling length and payload height. If one or more sensors indicate that the bottom of the payload is within a threshold of the ground, the trigger device 202 may set an output trigger to enable the operation of the detection device 204 .
The trigger device 202 may include enable inputs from a mission management state machine or operator input so as to prevent a trigger in unwanted situations. For example, the trigger device 202 might not enable the detection device 204 in some instances to account for events in flight that could cause a change in one or more parameters measured by the detection device that might otherwise seem to indicate that a touchdown event has occurred. Such events could include a vibration associated with the collective, paratroopers exiting the aircraft, etc.
The detection device 204 may compute an event indicator function that is a combination of collective, engine power, and torque parameters. The function may be computed by scaling and weighing these parameters through a set of nonlinear gains and dynamic weights. Filters may be selected to reflect parameter dynamics.
Referring to FIG. 3 , a system environment 300 for detecting a touchdown event is shown. The system 300 may be implemented as part of the system 200 . For example, the system 300 may be implemented in connection with the detection device 204 . One or more gains (e.g., nonlinear gains) 302 a , 302 b , and 302 c , and/or transfer functions/filters 304 a , 304 b , 304 c , may be applied with respect to vertical performance variables or parameters, such as collective, engine power, and shaft torque, to generate an indication 306 of a touchdown event. In case of additional sensors that provide load position and location information, such as load force sensors, cameras, a laser-based sensor, etc., these sensors can be included in the detection device 204 to augment the detection.
The nonlinear gains 302 a , 302 b , and 302 c may be selected to incorporate deadbands and nonlinearities in the underlying parameters. Scaling and filtering may be performed to non-dimensionalize and time-align a step-change event in all parameters so that the event can be detected robustly. Filters and nonlinear gains might not be needed if the parameters do not have nonlinearities and occur in similar time-scale. There are many ways of designing these filters and tuning them as would be known to one of skill in the art—the system 300 captures all such instances and embodiments.
During a slung payload touchdown event, the output of the detection device 204 or the indicator 306 may undergo a step change from an airborne-regime to a ground-contact-regime. One or more thresholds may be selected, in terms of magnitude and/or time, to distinguish between the two regimes. In the event that the aircraft lifts off with the payload attached, the detection device 204 or the indicator 306 may experience a change in value corresponding to the airborne-regime. A detachment device 206 may process the output of the detection device 204 (or the indicator 306 ) to trigger detachment or disengagement of the payload.
The detachment device 206 may receive one or more inputs from an operator input data bus that may serve as an override. The operator may be a pilot, a remote pilot, an onboard operator, or a remote operator. The override may be used to selectively detach or retain a payload, potentially irrespective of the output of the detection device 204 . In some instances, the input driving the operator input data bus may be remotely located from the detachment device 206 or an aircraft.
In embodiments where load sensors are available in the sling system (e.g., sling 22 ), signals from the load sensors may serve as inputs to the detection device 204 or the indicator 306 . The signals from the load sensors may be weighted in proportion to the reliability of the load sensors. Incorporating the signals from the load sensors may enhance the robustness of payload touchdown detection.
Turning now to FIG. 4 , a flow chart of an exemplary method 400 is shown. The method 400 may be executed by one or more systems, components, or devices, such as those described herein (e.g., the system 100 , the system 200 , and/or the system 300 ). The method 400 may be used to robustly and accurately detect a touchdown event in connection with a payload of an aircraft.
In block 402 , data associated with the operation of the aircraft may be obtained. For example, the data may pertain to operator input data, mission data, and/or data from one or more sensors.
In block 404 , the data of block 402 may be processed. As part of block 404 , the data may be filtered to remove extraneous data, to reduce the impact of noise on one or more measurements, or to obtain a data profile that more closely mirrors or resembles the physical world.
In block 406 , a determination may be made whether, based on the processed data of block 404 , a touchdown detection event should be enabled. A touchdown detection event might be enabled when a mission phase associated with the aircraft indicates as such and the aircraft is within a threshold distance of the ground or an object. If a touchdown detection event should be enabled (e.g., the “yes” path is taken out of block 406 ), flow may proceed from block 406 to block 408 . Otherwise (e.g., the “no” path is taken out of block 406 ), flow may proceed from block 406 to block 402 .
In block 408 , a determination may be made whether, based on the processed data of block 404 , a touchdown event has occurred. If so (e.g., the “yes” path is taken out of block 408 , flow may proceed from block 408 to block 410 ). Otherwise (e.g., the “no” path is taken out of block 408 ), flow may proceed from block 408 to block 402 .
In block 410 , a load or payload may be detached or decoupled from the aircraft.
The method 400 is illustrative. In some embodiments, one or more of the blocks or operations (or a portion thereof) may be optional. In some embodiments, the blocks or operations may execute in an order or sequence different from what is shown in FIG. 4 . In some embodiments, one or more blocks or operations not shown may be included. For example, and as described above, an operator input may serve as an override to selectively detach or retain a load or payload.
Aspects of the disclosure may be applied in connection with a controlled vertical flight (phase). In some embodiments, controlled vertical flight may include descent at a fixed velocity or a stable altitude hold. Stable altitude hold may correspond to a controlled mode where a control algorithm or device may change a value to hold or maintain a particular value in the event of, e.g., payload detachment or alleviation. Controlled vertical flight may be used in connection with one or more of the examples described herein for selectively detaching or decoupling a payload.
In some embodiments, an estimate of gross weight changes associated with an aircraft may be provided. Such changes may be brought about by, e.g., load or fuel tank jettison events. Embodiments of the disclosure may be applied in connection with any “cause-effect” system that demonstrates a change in “effect” to detect a change in “cause” under constant velocity or position control. For example, aspects of the disclosure may be applied in connection with elevator or escalator load and motor torque.
As described herein, in some embodiments various functions or acts may take place at a given location and/or in connection with the operation of one or more apparatuses, systems, or devices. For example, in some embodiments, a portion of a given function or act may be performed at a first device or location, and the remainder of the function or act may be performed at one or more additional devices or locations.
Embodiments may be implemented using one or more technologies. In some embodiments, an apparatus or system may include one or more processors, and memory storing instructions that, when executed by the one or more processors, cause the apparatus or system to perform one or more methodological acts as described herein. Various mechanical components known to those of skill in the art may be used in some embodiments.
Embodiments may be implemented as one or more apparatuses, systems, and/or methods. In some embodiments, instructions may be stored on one or more computer-readable media, such as a transitory and/or non-transitory computer-readable medium. The instructions, when executed, may cause an entity (e.g., an apparatus or system) to perform one or more methodological acts as described herein.
Aspects of the disclosure have been described in terms of illustrative embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure. For example, one of ordinary skill in the art will appreciate that the steps described in conjunction with the illustrative figures may be performed in other than the recited order, and that one or more steps illustrated may be optional. | Embodiments are directed to obtaining data associated with at least one aircraft flight parameter when an aircraft is being operated in flight; processing the data to determine that the at least one aircraft flight parameter indicates a change in value in an amount greater than a threshold; and decoupling a load from the aircraft based on determining that the at least one aircraft flight parameter indicates the change in value in the amount greater than the threshold. | 1 |
REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of U.S. Provisional Patent Application Serial No. 60/364,150, filed on Mar. 15, 2002, and U.S. Provisional Patent Application Serial No. 60/414,345, filed on Sep. 30, 2002. The contents of the provisional applications are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to network devices, including switches, routers and bridges, which allow for data to be routed and moved in computing networks. More specifically, the present invention provides for a scalable packet filter for filtering packet data in network devices.
[0004] 2. Description of Related Art
[0005] In computer networks, each element of the network performs functions that allow for the network as a whole to perform the tasks required of the network. One such type of element used in computer networks is referred to, generally, as a switch. Switches, as they relate to computer networking and to Ethernet, are hardware-based devices which control the flow of data packets or cells based upon destination address information which is available in each packet. A properly designed and implemented switch should be capable of receiving a packet and switching the packet to an appropriate output port at what is referred to wirespeed or linespeed, which is the maximum speed capability of the particular network.
[0006] Basic Ethernet wirespeed is up to 10 megabits per second, and Fast Ethernet is up to 100 megabits per second. Another type of Ethernet is referred to as 10 gigabit Ethernet, and is capable of transmitting data over a network at a rate of up to 10,000 megabits per second. As speed has increased, design constraints and design requirements have become more and more complex with respect to following appropriate design and protocol rules and providing a low cost, commercially viable solution.
[0007] This is similarly important with respect to filtering by a network device. Filtering by a network device may be as simple as classification of data passing through the network device to allow an administrator to determine the type and quantity of data flowing through the network device. Additionally, filtering may also include management of flows through the network device and allow for the specific handling of certain data based on fields within the packet. These fields contain data about the source, destination, protocol and other properties of the packet.
[0008] In many network devices, such filtering is often simplistic and filters packets through “brute force” methods. Many such filtering systems are similar to the filtering processes described in U.S. Pat. No. 6,335,935, which is hereby incorporated by reference, that provide filtering results but require that a significant portion of the network device be utilized in the filtering process. The filtering processes are generally not expandable, often take a great number of cycles to process and increase the latency periods for address resolution lookup (ARL) and ingress processes.
[0009] As such, there is a need for an efficient filtering method and a scalable filtering mechanism for data passing through network devices. In addition, there is a need for a method that allows for fewer cycles to process the filtering and decreases the latency for other processes performed by the network device. Such a filter should allow for the incoming packet to be parsed and for relevant packet fields of interest to users to be identified.
SUMMARY OF THE INVENTION
[0010] It is an object of this invention to overcome the drawbacks of the above-described conventional network devices and methods. The present invention provides for a scalable packet filter for data packets passing through network devices.
[0011] According to one aspect of this invention, a network device for network communications is disclosed. The device includes at least one data port interface, the at least one data port interface supporting at least one data port transmitting and receiving data and a CPU interface, the CPU interface configured to communicate with a CPU. The network device also includes a memory communicating with the at least one data port interface, a memory management unit, the memory management unit including a memory interface for communicating data from the at least one data port interface and the memory and a communication channel, the communication channel for communicating data and messaging information between the at least one data port interface, the CPU interface, the memory, and the memory management unit. The network device also includes a fast filtering processor, the fast filtering processor filtering packets coming into the at least one data port interface, and taking selective filter action on a particular packet of the packets based upon specified packet field values. The specified packet field values are obtained by applying a filter mask, obtained from a field table, to the particular packet and the selective filter action is obtained from a policy table based on the specified packet field values.
[0012] Alternatively, the network device fast filtering processor may be programmable by inputs from the CPU through the CPU interface. The at least one data port interface may include a flow table interface and a flow table thereupon, wherein the specified packet field values are used to obtain a policy value from the flow table and the selective filter action is obtained from a policy table based on the policy value. Additionally, the at least one data port interface, CPU interface, memory, memory management unit, communications channel, fast filtering processor, and the flow table may be implemented on a common semiconductor substrate.
[0013] Also, the specified packet field values may be selected based upon flows of data packets through the network device. The flows of data packets may be defined by at least one of a source internet protocol address, a destination internet protocol address, a source media access controller address, a destination media access controller address and a protocol for the particular packet. The fast filtering processor may also include a priority assignment unit for assigning a weighted priority value to untagged packets entering the at least one data port interface. The fast filtering processor may filter the packets independent of the CPU interface, and therefore without communicating with the CPU. The network switch may also include a tagging unit which applies an IEEE defined tag to incoming packets, the IEEE defined tag identifying packet parameters, including class-of-service.
[0014] According to another aspect of this invention, a method of handling data packets in a network device is disclosed. An incoming packets is placed into an input queue and the input data packets are applied to an address resolution logic engine. A lookup is performed to determine whether certain packet fields are stored in a lookup table and the incoming packet is filtered through a fast filtering processor based on specified packet field values obtained from the incoming packets to obtain a selective filter action. The packet is discarded, forwarded, or modified based upon the filtering. The selective filter action is obtained from a policy table based on the specified packet field values.
[0015] The method may include obtaining a policy value from a flow table based on the specified packet field values and obtaining the selective filter action from a policy table based on the policy value. Additionally, the steps of performing a lookup and filtering the incoming packet through a fast filtering processor may be performed concurrently. Also, the filtering of the incoming packet may be based on specified packet field values selected based upon flows of data packets through the network device. The incoming packet may be tagged with an IEEE defined tag, including class-of-service (COS) priority.
[0016] These and other objects of the present invention will be described in or be apparent from the following description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] For the present invention to be easily understood and readily practiced, preferred embodiments will now be described, for purposes of illustration and not limitation, in conjunction with the following figures:
[0018] [0018]FIG. 1 is a general block diagram of elements of an example of the present invention;
[0019] [0019]FIG. 2 is a data flow diagram of a packet on ingress to the switch; and
[0020] [0020]FIG. 3 is a flow chart illustrating a process of filtering packets, according to one embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] [0021]FIG. 1 illustrates a configuration wherein a switch-on-chip (SOC) 10 , in accordance with one embodiment of the present invention, is illustrated. The following are the major blocks in the chip: Gigabit Port Interface Controller (GPIC) 30 ; Interconnect Port Interface Controller (IPIC) 60 ; CPU Management Interface Controller (CMIC) 40 ; Common Buffer Pool (CBP)/Common Buffer Manager (CBM) 50 ; Pipelined Memory Management Unit (PMU) 70 ; and Cell Protocol Sideband (CPS) Channel 80 . The above components are discussed below. In addition, a Central Processing Unit (CPU) (not shown) can be used as necessary to program the SOC 10 with rules which are appropriate to control packet processing. However, once SOC 10 is appropriately programmed or configured, SOC 10 operates, as much as possible, in a free running manner without communicating with CPU.
[0022] The Gigabit Port Interface Controller (GPIC) module interfaces to the Gigabit port 31 . On the medium side it interfaces to the TBI/GMII or MII from {fraction (10/100)} and on the chip fabric side it interfaces to the CPS channel 80 . Each GPIC supports a 1 Gigabit port or a {fraction (10/100)} Mbps port. Each GPIC performs both the ingress and egress functions.
[0023] On the Ingress, the GPIC supports the following functions: 1) L2 Learning (both self and CPU initiated); 2) L2 Management (Table maintenance including Address Aging); 3) L2 Switching (Complete Address Resolution: Unicast, Broadcast/Multicast, Port Mirroring, 802.1Q/802.1p); 4) FFP (Fast Filtering Processor), including the IRULES Table); 5) a Packet Slicer; and 6) a Channel Dispatch Unit.
[0024] On the Egress the GPIC supports the following functions: 1) Packet pooling on a per Egress Manager (EgM)/COS basis; 2) Scheduling; 3) HOL notification; 4) Packet Aging; 5) CBM control; 6) Cell Reassembly; 7) Cell release to FAP (Free Address Pool); 8) a MAC TX interface; and 9) Adds Tag Header if required.
[0025] It should be noted that any number of gigabit Ethernet ports 31 can be provided. In one embodiment, 12 gigabit ports 31 can be provided. Similarly, additional interconnect links to additional external devices and/or CPUs may be provided as necessary. In addition, while the present filtering process is discussed with respect to the network device disclosed herein, the use of the scalable packet filter of the present invention is not limited to such a network device.
[0026] The Interconnect Port Interface Controller (IPIC) 60 module interfaces to CPS Channel 80 on one side and a high speed interface, such as a HiGig™ interface, on the other side. The HigGig is a XAUI interface, providing a total bandwidth of 10 Gbps.
[0027] The CPU Management Interface Controller (CMIC) 40 block is the gateway to the host CPU. In it's simplest form it provides sequential direct mapped accesses between the CPU and the network device. The CPU has access to the following resources on chip: all MIB counters; all programmable registers; Status and Control registers; Configuration registers; ARL tables; 802.1Q VLAN tables; IP Tables (Layer-3); Port Based VLAN tables; IRULES Tables; and CBP Address and Data memory.
[0028] The bus interface is a 66 MHz PCI. In addition, an 12C (2-wire serial) bus interface is supported by the CMIC, to accommodate low-cost embedded designs where space and cost are a premium. CMIC also supports: both Master and Target PCI (32 bits at 66 MHz); DMA support; Scatter Gather support; Counter DMA; and ARL DMA.
[0029] The Common Buffer Pool (CBP) 50 is the on-chip data memory. Frames are stored in the packet buffer before they are transmitted out. The on-chip memory size is 1.5 Mbytes. The actual size of the on-chip memory is determined after studying performance simulations and taking into cost considerations. All packets in the CBP are stored as cells. The Common Buffer Manager (CBM) does all the queue management. It is responsible for: assigning cell pointers to incoming cells; assigning PIDs (Packet ID) once the packet is fully written into the CBP; management of the on-chip Free Address Pointer pool (FAP); actual data transfers to/from data pool; and memory budget management.
[0030] The Cell Protocol Sideband (CPS) Channel 80 is a channel that “glues” the various modules together as shown in FIG. 1. The CPS channel actually consists of 3 channels:
[0031] a Cell (C) Channel: All packet transfers between ports occur on this channel;
[0032] a Protocol (P) Channel: This is a synchronous to the C-channel and is locked to it. During cell transfers the message header is sent via the P-channel by the Initiator (Ingress/PMMU); and
[0033] a Sideband (S) Channel: its functions are CPU management, MAC counters, register accesses, memory accesses etc; chip internal flow control, Link updates, out queue full etc; and chip inter-module messaging, ARL updates, PID exchanges, Data requests etc. The side band channel is 32 bits wide and is used for conveying Port Link Status, Receive Port Full, Port Statistics, ARL Table synchronization, Memory and Register access to CPU and Global Memory Full and Common Memory Full notification.
[0034] When the packet comes in from the ingress port the decision to accept the frame for learning and forwarding is done based on several ingress rules. These ingress rules are based on the Protocols and Filtering Mechanisms supported in the switch. The protocols which decide these rules could include, for example, IEEE 802.1d (Spanning Tree Protocol), 802.1p and 802.1q. Extensive Filtering Mechanism with inclusive and exclusive Filters is supported. These Filters are applied on the ingress side, and depending on the filtering result, different actions are taken. Some of the actions may involve changing the 802.1p priority in the packet Tag header, changing the Type Of Service (TOS) Precedence field in the IP Header or changing the egress port.
[0035] The data flow on the ingress into the switch will now be discussed with respect to FIG. 2. As the packet comes in, it is put in the Input FIFO, as shown in step 1 . An Address Resolution Request is sent to the ARL Engine as soon as first 16 bytes arrive in the Input FIFO at 2 a . If the packet has 802.1q Tag then the ARL Engine does the lookup based on 802.1q Tag in the TAG BASED VLAN TABLE. If the packet does not contain 802.1q Tag then ARL Engine gets the VLAN based on the ingress port from the PORT BASED VLAN TABLE. Once the VLAN is identified for the incoming packet, ARL Engine does the ARL Table search based on Source Mac Address and Destination Mac Address. The key used in this search is Mac Address+VLAN Id. If the result of the ARL search is one of the L3 Interface Mac Address, then it does the L3 search to get the Route Entry. If an L3 search is successful then it modifies the packet as per Packet Routing Rules.
[0036] At step 2 b , a Filtering Request is sent to Fast Filtering Processor (FFP) as soon as first 64 bytes arrive in the Input FIFO. The outcome of the ARL search, step 3 a , is the egress port/ports, the Class Of Service (COS), Untagged Port Bitmap and also in step 3 b the modified packet in terms of Tag Header, or L3 header and L2 Header as per Routing Rules. The FFP applies all the configured Filters and results are obtained from the RULES TABLE.
[0037] The outcome of the Filtering Logic, at 3 c , decides if the packet has to be discarded, sent to the CPU or, in 3 d , the packet has to be modified in terms of 802.1q header or the TOS Precedence field in the IP Header. If the TOS Precedence field is modified in the IP Header then the IP Checksum needs to be recalculated and modified in the IP Header.
[0038] The outcome of FFP and ARL Engine, in 4 a , are applied to modify the packet in the Buffer Slicer. Based on the outcome of ARL Engine and FFP, 4 b , the Message Header is formed ready to go on the Protocol Channel. The Dispatch Unit sends the modified packet over the cell Channel, in 5 a , and at the same time, in 5 b , sends the control Message on the Protocol Channel. The Control Message contains the information such as source port number, COS, Flags, Time Stamp and the bitmap of all the ports on which the packet should go out and Untagged Bitmap.
[0039] In prior art implementations of filtering, in some cases, a filter database was employed that contained filters to be applied to the packets and associated rules table for each filter that matched the packet data. For the fields, which are of interest, the mask could be set to all 1's and for other fields the mask could be set to zero. The filter logic then goes through all the masks and applies the mask portion of the filter to portions of the packet. The result of this operation generates a search key, the search key being used to search for the match in the rules table. A Metering table is also provided, where this table is used to determine if the packet is in-profile or out-profile. The index to this table is the Meter ID Table, where the meter id is obtained when there is a Full Match in the rules table for a given filter mask. The counters are implemented as a token bucket.
[0040] If the packet is in-profile, then the packet is sent out as in-profile and actions associated with in-profile are taken. At the end of the packet, the packet length is subtracted from the BucketCount. If the BucketCount is less than or equal to the threshold, measured in tokens, then the associated status bit is changed to be out-profile otherwise there is no change in the status bit. If the packet is out-profile, the BucketCount is left unchanged. The threshold value is hard coded to a certain number of tokens for all port speeds. When the refresh timer expires, new tokens are added to the token bucket and if the BucketCount is greater than or equal to the threshold, the status bit is set to in-profile; otherwise it is out-profile. The status bit can change in this example at two points in time: 1) When the packet is done from in-profile to out-profile and 2) when the refresh tokens are added (from out-profile to in-profile).
[0041] In contrast to the prior art processes and filters, the present invention makes many improvements. The present scalable packet filter allows for classification based on IP fields: Source IP, Destination IP, Protocol, User Datagram Protocol/Transmission Control Protocol (UDP/TCP), Source (UDP/TCP) Port and Destination (UDP/TCP) Port or based on Source and Destination IP subnets. The present scalable packet filter allows for classification based on L2 fields, such as destination Media Access Controller (MAC) Address, source MAC Address and Virtual Local Area Network (VLAN). The present scalable packet filter also allows for flow based metering in order to be able to restrict either Individual flows or Subnets. The present scalable packet filter allows for a single unified design for the chip, has a scalable number of Flows, and is designed with issues like routing and latency in mind.
[0042] The present scalable packet filtering mechanism parses fields of interest that need to be parsed from the packet. These fields include Ethernet and IPv4 fields, as well as IPv6 field, which are parsed. Also, while more than a 100 IP Protocol are defined, the ones of real interest may be only TCP and UDP and the only Layer 4 protocols parsed may be TCP and UDP. Some possible fields that may be parsed are: destination MAC address (48 bits); source MAC Address (48 bits); VLAN tag (VLAN ID and Priority) (16 bits); destination IP Address (32 bits); source IP Address (32 bits); Protocol—encoded in 3 bits as below; IP Protocol (8)—encoded in 2 bits as below; Destination TCP/UDP Port (16 bits); Source TCP/UDP (16 bits); Ingress Port (4-5 bits depending on the number of ports on chip); TOS (3 bits); and DSCP (6 bits).
[0043] Prior network devices have not generally parsed Layer 4 protocols on ingress. It may be necessary to enhance the ingress to add this parsing ability. The IP Header in the packet may carry options that make the IP Header of variable length. Also, in the need to conserve space, the Protocol and IP Protocol field will be encoded. Encoding for 3 bit Protocol Field:
TABLE 1 Value Meaning 000 Ipv4 Packet 001 Ipv6 Packet 011-111 Reserved
[0044] Encoding for 2 bit Protocol Field:
TABLE 2 Value Meaning 00 TCP Packet 01 UDP Packet 10-11 Reserved
[0045] While it is possible for a user to filter on all of the above fields—230 bits (and more) at the same time, in reality, it is likely that fewer are actually needed. In order to simplify the design and to support a larger number of flows, the total number of fields that need to be compared at one time is limited. The combinations likely to be used include the following:
[0046] L2 Flow Specification—Source MAC Address, Destination MAC Address and VLAN ID and Source Port is a total of 48+48+12+5=113 bits.
[0047] IP Flow Specification—Source IP Address, Destination IP Address, Source TCP/UDP Port, Destination TCP/UDP Port, Protocol, IP Protocol, TOS and Ingress Port is a total of 32+32+16+16+2+3+8+5=114 bits.
[0048] Source/Destination Only—MAC Address, IP Address, TCP/UDP Port, Ingress Port is a total of 48+12+32+5=111 bits.
[0049] IP Address range specification via Subnets—Source IP Subnet and Destination IP Subnet, TCP/UDP Port and Ingress Port is total of 32+32+16+5=85.
[0050] There is also a need to support filtering on various fields like VLAN, Ingress Port, etc. Finally, as a catchall, this embodiment of the present filtering process supports an arbitrary 16 bit field in the packet that is selected in the ingress.
[0051] The Field Table specifies the fields of interest for this filter and is described below. For each valid entry in the Field Table, a search is made in the flow table. The number of field table entries that can supported is thus dependent on the number of cycles available to process each packet. It should be possible to support 8-16 entries for Gigabit ports and, for example, 4 entries for 10 Gigabit Ethernet ports.
[0052] The user may specify Fields in three portions. The first two portions are of 48 bits each and the third of 16 bits. The portion sizes have been selected in this way to make it easy for the user to specify either MAC addresses or IP Address/L4 Ports combination in the 48 bit portions and the VLAN ID and other fields in the 16 bit portion. There is also an option to have the user specify an arbitrary 16 bits of the packet (only up to 80 bytes into the packet). The offset for this field is specified in the Ingress and parsed there before it is passed to the SPF logic. A description of the Field Table is provided in TABLE 3:
TABLE 3 Field Size Description F1 3 This selects the first 48 bits of the Filter. 000—Source MAC Address 001—Destination MAC Address 010—Source IP Address & L4 Source Port 011—Destination IP Address & L4 Port 100—Use User Defined 16 bit field F2 3 This is used to select the second 48 bits to filter on 000—Source MAC Address 001—Destination MAC Address 010—Source IP Address & L4 Source Port 011—Destination IP Address & L4 Port 100—Use User Defined 16 bit field L2L3 2 This is used to select a 16 bit field to filter on. 00—Use VLAN ID/CFI/PRIORITY 01—Use encoded Protocol, Encoded IP Protocol and 8 bit TOS fields. 10—Use User Defined 16 bit field VALID 1 Indicates valid mask MASK 118 Mask to mask out the unnecessary bits TOTAL 127
[0053] The source port is included in the search key, but a port bitmap may be used instead. Any of the fields not to be used in the search may be masked out using the Mask. The Mask may further be used to specify IP Subnets for both in the Source and Destination IP addresses. The DSCP Field is not used as part of the search key.
[0054] With respect to flows, IP Flows may be completely specified by the Source IP, Destination IP, Source L4 Port, Destination L4 Port, Ingress Port, IP Protocol and TOS. In addition, Address ranges and Port ranges are supported usually only with the mask.
[0055] The Flow Table identifies the flows that the user wants to classify and prioritize. In order to be able to support a large number of flows, this table can be hashed to improve access thereto. The question that arises is when in the packet processing the Flow Identification needs to be performed and when the actions should be taken. Performing this after the ARL lookups increases the time needed in the ARL to process the packet and hence may not be an option for the 10 Gig ports. The recommendation is that this be performed in parallel with the ARL lookup. The results of the Flow Lookup are applied to the result of the ARL lookup to obtain the final results. The flow table is provided below:
TABLE 4 Field Size Description VALID 1 Indicates a valid Flow Entry MASKNUM 4 Mask Number for which this entry was made. KEY 118 The Search Key obtained as a result of applying the Field Table fields METERID 8 The ID of the Meter to be applied if the Key matches. (More Meters would be good) COUNTER 8 Counter to be incremented POLICY 8 In Profile Policy OOP POLICY 8 Out of Profile Policy TOTAL 156
[0056] A Flow Policy Table specifies the actions to be taken on the packet. A different policy may be specified for packet that are in-profile and for packet out-of-profile. It is expected that initially 256 policies will be supported. An example of the Flow Policy Table is provided below:
TABLE 5 Field Size Description VALID 1 Indicates a valid Flow Entry CHANGE_PRI 2 00—NO CHANGE 01—NEW PRI 10—FROM TOS 11—DO NOT CHANGE CHANGE_IPRI 2 00—NO CHANGE 01—NEW IPRI 10—FROM TOS 11—DO NOT CHANGE CHANGE_TOS 2 00—NO CHANGE 01—NEW TOS 10—FROM PRI 11—DO NOT CHANGE CHANGE_DSCP 2 00—NO CHANGE 01—NEW DSCP 10—DO NOT CHANGE 11—RESERVED CHANGE_VLAN 2 00—NO CHANGE 01—NEW VLAN 10—DO NOT CHANGE 11—RESERVED PKTH 3 000—NO ACTION 001—DROP 010—DO NOT DROP 011—REDIRECT 100—DO NOT REDIRECT 101—COPY TO CPU 110—EGRESS MASK PRI 3 Priority to be used if meter not specified or packet in profile IPRI 3 Internal Priority TOS 3 TOS Field in packet DSCP 6 DSCP Field in packet DSTPORT 8 Destination Port DSTMOD 8 Destination Module VLAN 12 New VLAN TOTAL 45
[0057] With respect to the above table, the DSTPORT & DSTMOD are concatenated to form the EGRESS_MASK. Also included in the filtering mechanism of the present invention, a Meter Table is provided to meter the fields and a counter table to provide a count of the number of packets. Details of both tables are given below:
TABLE 6 Field Size Description BUCKETCOUNT 19 The BUCKETSIZE is configurable to one of the following 8 sizes: 16K, 20K, 28K, 40K, 76K, 140K, 268K or 524K tokens. Effectively, this varies the number of bits in the BUCKETCOUNT REFRESHCOUNT 10 The number of tokens that are added to the bucket each 8 microsecond refresh interval. The values are from 0 to 1023 tokens. 1 means 1 token and 1023 means 1023 tokens. BUCKETSIZE 3 The current count of tokens in the bucket. The count is reduced with incoming packets and is increased by REFRESHCOUNT tokens every 8 microsecond refresh interval. TOTAL 32
[0058] [0058] TABLE 7 Field Size Description COUNT 32 Count of number of packets TOTAL 32
[0059] The FFP logic process is illustrated in FIG. 3. In step 301 , for each filter to be applied, the Field Table is accessed to determine the fields of the packet to be examined. The Field Table also provides a mask to be applied to the packet to obtain the field values, in Step 302 . The Flow Table is then searched, in Step 303 , for every valid entry of the Field Table and an In-Profile Policy or an Out-Of-Profile Policy is obtained from the Field Table, Step 304 . An action is then taken based on the search of the Flow Policy Table. If the packet is an untagged packet, then the ingress must tag the packet with information got from ARL Logic, before going through the filtering process.
[0060] The above process and scalable packet filter provide a more elegant filtering process. The above process is expandable because the tables can be altered easily and the filtering can be accomplished with greater precision with respect to certain fields that a user desires to filter. The above described process also has greater applicability to the control and characterization of flows than the prior art filtering processes.
[0061] The above-discussed configuration of the invention is, in one embodiment, embodied on a semiconductor substrate, such as silicon, with appropriate semiconductor manufacturing techniques and based upon a circuit layout which would, based upon the embodiments discussed above, be apparent to those skilled in the art. A person of skill in the art with respect to semiconductor design and manufacturing would be able to implement the various modules, interfaces, and components, etc. of the present invention onto a single semiconductor substrate, based upon the architectural description discussed above. It would also be within the scope of the invention to implement the disclosed elements of the invention in discrete electronic components, thereby taking advantage of the functional aspects of the invention without maximizing the advantages through the use of a single semiconductor substrate.
[0062] Although the invention has been described based upon these preferred embodiments, it would be apparent to those of skilled in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of the invention. In order to determine the metes and bounds of the invention, therefore, reference should be made to the appended claims. | A network device for network communications is disclosed. The device includes at least one data port interface, the at least one data port interface supporting at least one data port transmitting and receiving data and a CPU interface, the CPU interface configured to communicate with a CPU. The network device also includes a memory communicating with the at least one data port interface, a memory management unit, the memory management unit including a memory interface for communicating data from the at least one data port interface and the memory and a communication channel, the communication channel for communicating data and messaging information between the at least one data port interface, the CPU interface, the memory, and the memory management unit. The network device also includes a fast filtering processor, the fast filtering processor filtering packets coming into the at least one data port interface, and taking selective filter action on a particular packet of the packets based upon specified packet field values. The specified packet field values are obtained by applying a filter mask, obtained from a field table, to the particular packet and the selective filter action is obtained from a policy table based on the specified packet field values. | 7 |
FIELD AND BACKGROUND OF INVENTION
Strand materials such as textile yarns, filaments and the like frequently are guided or transported along predetermined paths of travel by entrainment of the strand materials about at least portions of circumferential strand receiving grooves of sheaves or pulleys. In certain strand handling operations, such pulleys or sheaves are driven or braked in order to control movement of or tension in the strand material while in other strand handling applications the rotation of such a sheave or pulley is used to measure lengths of strand material or rates of movement of strand material. Examples of such operations may be found in White U.S. Pat. No. 3,797,775 and White et al U.S. Pat. No. 3,858,416.
As will be appreciated, slippage of a strand material relative to an engaged sheave or pulley may present no difficulty where the only function for the sheave or pulley is to guide strand material along a desired path of travel. However, slippage can introduce significant inaccuracies in circumstances where strand material tension is being controlled or some characteristic of strand movement is being controlled or measured.
It has been proposed heretofore that the coordination of sheave rotation with strand movement may be improved by more positively gripping a strand which engages a sheave. In certain prior structures designed for such a purpose, an annular member or ring defining a circumferential groove has been mounted on a central hub which is affixed, by suitable means to a central shaft. While such arrangements have achieved some success, difficulty has on occasion been encountered due to high rates of change of rotational speeds such as occur on rapid acceleration or braking of strand movement. Relatively high torques arising under such circumstances may cause slippage of the elastomeric ring member relative to the hub, leading to loss of control and inaccuracy in measurements.
BRIEF DESCRIPTION OF INVENTION
It is an object of the present invention to improve coordination of sheave rotation with strand movement by accomplishing positive gripping of a strand which engages a sheave while accommodating high rates of change in torque applied. In realizing this object of the present invention, possibilities are opened for more accurately achieving strand feeding or supply and for more accurately determining characteristics of strand movement such as speed or quantity delivered.
Yet a further object of the present invention is to accommodate torque variations while more positively gripping a strand received within a circumferential groove of a sheave. In realizing this object of the present invention, a strand is passed in a tortuous, cusp-like strand engaging zone defined between opposing inner surfaces of outwardly diverging sidewall portions of an annular body.
BRIEF DESCRIPTION OF DRAWINGS
Some of the objects of the invention having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings, in which
FIG. 1 is a perspective view of a sheave in accordance with the present invention partly broken away to clarify certain constructional features;
FIG. 2 is an enlarged vertical section view through portions of the sheave of FIG. 1;
FIG. 3 is an exploded perspective view of components making up the sheave of FIGS. 1 and 2;
FIG. 4 is a plan view of the sheave of FIGS. 1 through 3, illustrating certain characteristics of a circumferential strand receiving groove thereof; and
FIG. 5 is an elevation view, in section, through a portion of the sheave of FIGS. 1 through 4, taken generally along the line 5--5 in FIG. 4.
DETAILED DESCRIPTION OF INVENTION
The present invention will be described hereinafter with particular reference to the accompanying drawings in which one practical embodiment of the present invention is illustrated. However, it is to be understood at the outset of the description which follows that it is contemplated that persons skilled in the applicable art may modify specific constructional details of the sheave of this invention while achieving the desirable results accomplished by this invention. Accordingly, the description is to be understood as a broad teaching directed to persons skilled in the art and not as restrictive on the scope of this invention.
Referring now more particularly to the accompanying drawings, FIG. 1 illustrates the sheave of the present invention, generally indicated at 10, as comprising a hub member 11 formed of any suitable material such as metal and constructed for attachment to a shaft 12 which will define an axis about which the sheave 10 rotates. It is contemplated that the shaft 12 will be connected to some appropriate device (not shown) which may, in accordance with the present invention, either be a motive means such as an electrical motor, a brake means such as a magnetic particle brake, or a signalling means such as a shaft position transducer. In instances where the device is a motive means such as an electrical motor, the sheave 10 functions as a strand advancing or feeding device. In instances where the device is a brake, the sheave 10 functions as a tension control. In instances where the device is a shaft angle transducer or the like, the sheave 10 functions to signal desired information such as the velocity at which strand material is being moved along a predetermined path of travel or the length of strand material which has been moved within a measured time interval. It is believed that such usages of the sheave 10 of the present invention will be readily comprehended by persons skilled in the applicable arts, and it is further contemplated that the sheave 10 of the present invention may have utility in all such applications.
Mounted on the hub 11 is a planar body 14 of a suitable material such as a filled plastic and which performs the function of a carrier for spacing an annular member 15 from the hub 11. The body 14 and hub 11 are fixed to the shaft 12 by appropriate means such as a set screw. As best seen in FIGS. 2 and 3, the spacer 14 and annular member 15 are provided with mating circumferential shoulders.
In accordance with important characteristics of the sheave 10 of the present invention, the sheave comprises a plurality of resilient spoke members 16. The spoke members 16 are collectively disposed in a star-like configuration, with adjacent ones of the members 16 being inclined at equal and opposite angles with respect to a radius bisecting the angle included therebetween. As indicated, a total of eight spoke members 16 are provided on either side of the planar spacer member 14. Due to this number of spoke members 16 having been provided, the direction of the spoke members 16 in such that they are subjected to compression and tension loading in response to gripping engagement with a strand as described more fully hereinafter. Such compression and tension loading is to be distinguished from the essentially flexural loading which occurs with a radially extending spike as is found in a traditional bicycle wheel construction, for example.
In accordance with other characterizing features of the present invention, an annular body 18 having outwardly diverging sidewall portions 18A and 18B is mounted on the annular member 15. The sidewall portions 18A, 18B define between opposing inner surfaces thereof a circumferential strand receiving groove of predetermined radial depth. Forces arising from engagement of a strand with the annular body 18 are transmitted to and from the shaft 12 through the hub 11, pins 20 connecting the spacer member 14 with the spoke members 16, pins 21 connecting the spoke members 16 with the annular member 15, and thence to or from the annular body 18. A plurality of strand gripping abutments 22 project inwardly into the groove from the opposing sidewall portions 18A, 18B. Each of the projecting abutments 22 has a predetermined dimension circumferentially of the annular body 18 and a predetermined radial dimension relative to the depth of the groove. Adjacent ones of the projecting abutments 22 project inwardly from alternate ones of the opposing sidewall surfaces and are spaced circumferentially one from another at predetermined circumferential distances.
In the form illustrated, the projecting abutments 22 form two series, with one series being formed integrally with each of the two sidewall portions 18A, 18AB. Each series of projecting abutments may comprise a predetermined number of abutments, with each abutment spanning a predetermined portion of the circumference of the strand receiving groove. In certain forms of sheaves in accordance with the present invention which have been proposed, each abutment spans from about three to about six degrees of the circumference of the strand receiving groove and adjacent abutments in a common series are spaced at radial center line distances of from about seven and one-half to about fifteen degrees. In such a sheave, the two series of abutments 18 are radially displaced one from another by one-half that arcuate distance, or from about three and three-quarters to about seven and one-half degrees. The circumferential extent and spacing of projecting abutments 22 one from another, in such a sheave, is such that each abutment has radially directed sidewalls spaced at approximately one and one-half circumferential degrees from the next adjacent abutment. Experience thus far demonstrates that such geometry of a strand engaging groove may be varied depending upon the specific characteristics of the strand being engaged and the function being performed by the sheave. Accordingly, the specific numerical examples here given will be understood as illustrative only and as being subject to adaptation for specific uses of the sheave 10.
The projecting abutments 22 are contained entirely within the radial depth of the strand receiving groove, having radial dimensions less than the radial depth of the groove. Further, each of the projecting abutments 22 preferably has an abutment surface facing an opposing sidewall surface, which abutment surface is arcuate about a center spaced further from the opposing sidewall surface than from the sidewall surface from which the abutment projects. Thus, when viewed in an enlarged section, the abutment surfaces of adjacent abutments would be seen to define a cusp-like strand engaging zone (FIG. 2). By reason of the circumferential spacing of adjacent abutments, the strand engaging zone is of a tortuous configuration (FIG. 4).
In use, strand material entering into the strand receiving groove defined between the outwardly diverging sidewall portions 18A, 18B engages the surfaces of the projecting abutments 22 and is directed into a tortuous path. By means of such a tortuous path, the strand is more positively gripped by the sheave 10 of the present invention. Torque transmitted to or from the annular body 18 moves through the spoke members 16 which are loaded under compression or tension, depending upon the particular direction of torque imposed.
It is contemplated that the strand gripping characteristics of the sheave 10 of the present invention may be enhanced, particularly for textile strand materials, where the material of the annular body 18 is an elastomeric material such as a polyurethane having a minimum durometer hardness of 49D. It is anticipated that the ability of the sheave 10 to maintain accuracy and to transmit sharp variations in torque loading will be enhanced where the spoke members 16 similarly provide some flexibility in compression and tension loading, as opposed to being essentially rigid. That is, the spoke members 16 may preferably be elastomeric. When so formed the members may be stamped or cast or molded as an integral body.
In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation. | A sheave for engaging strand materials such as textile fabric yarns and the like. The sheave has spoke members transferring torques to and from a hub under compression and tension loading. The sheave also has an annular strand engaging groove with abutments for enhancing gripping engagement with a strand. | 8 |
RELATED APPLICATION DATA
This application is a continuation of Ser. No. 12/116,117, filed May 6, 2008 (now U.S. Pat. No. 7,756,290) which is a continuation of Ser. No. 11/452,662, filed Jun. 13, 2006 (now U.S. Pat. No. 7,369,678) which is a continuation of Ser. No. 10/819,716, filed Apr. 6, 2004 (now U.S. Pat. No. 7,062,069), which is a continuation of Ser. No. 10/215,389, filed Aug. 7, 2002 (now U.S. Pat. No. 6,718,047), which is a continuation of Ser. No. 09/503,881, filed Feb. 14, 2000 (now U.S. Pat. No. 6,614,914), which is a continuation in part of application Ser. No. 09/482,749, filed Jan. 13, 2000 (now abandoned). These prior applications and patents are incorporated herein by reference.
TECHNICAL FIELD
The present disclosures relates to encoding media content, such as images, audio and video.
BACKGROUND AND SUMMARY
Digital watermarking is a process for modifying media content to embed a machine-readable code into the data content. The data may be modified such that the embedded code is imperceptible or nearly imperceptible to the user, yet may be detected through an automated detection process. Most commonly, digital watermarking is applied to media such as images, audio signals, and video signals. However, it may also be applied to other types of data, including documents (e.g., through line, word or character shifting), software, multi-dimensional graphics models, and surface textures of objects.
Digital watermarking systems have two primary components: an embedding component that embeds the watermark in the media content, and a reading component that detects and reads the embedded watermark. The embedding component embeds a watermark pattern by altering data samples of the media content. The reading component analyzes content to detect whether a watermark pattern is present. In applications where the watermark encodes information, the reader extracts this information from the detected watermark.
One challenge to the developers of watermark embedding and reading systems is to ensure that the watermark is detectable even if the watermarked media content is transformed in some fashion. The watermark may be corrupted intentionally, so as to bypass its copy protection or anti-counterfeiting functions, or unintentionally through various transformations that result from routine manipulation of the content. In the case of watermarked images, such manipulation of the image may distort the watermark pattern embedded in the image.
This document describes watermark structures, and related embedders, detectors, and readers for processing the watermark structures. In addition, it provides a variety of methods and applications associated with the watermark structures, embedders, detectors and readers. While adapted for images, the watermark system applies to other electronic and physical media. For example, it can be applied to electronic objects, including image, audio and video signals. It can be applied to mark blank paper, film and other substrates, and it can be applied by texturing object surfaces for a variety of applications, such as identification, authentication, etc. The detector and reader can operate on a signal captured from a physical object, even if that captured signal is distorted.
The watermark structure can have multiple components, each having different attributes. To name a few, these attributes include function, signal intensity, transform domain of watermark definition (e.g., temporal, spatial, frequency, etc.), location or orientation in host signal, redundancy, level of security (e.g., encrypted or scrambled). When describing a watermark signal in the context of this document, intensity refers to an embedding level while strength describes reading level (though the terms are sometimes used interchangeably). The components of the watermark structure may perform the same or different functions. For example, one component may carry a message, while another component may serve to identify the location or orientation of the watermark in a combined signal. Moreover, different messages may be encoded in different temporal or spatial portions of the host signal, such as different locations in an image or different time frames of audio or video.
Watermark components may have different signal intensities. For example, one component may carry a longer message, yet have smaller signal intensity than another component, or vice-versa. The embedder may adjust the signal intensity by encoding one component more redundantly than others, or by applying a different gain to the components. Additionally, watermark components may be defined in different transform domains. One may be defined in a frequency domain, while another may be defined in a spatial or temporal domain.
The watermark components may be located in different spatial or temporal locations in the host signal. In images, for example, different components may be located in different parts of the image. Each component may carry a different message or perform a different function. In audio or video, different components may be located in different time frames of the signal.
The watermark components may be defined, embedded and extracted in different domains. Examples of domains include spatial, temporal and frequency domains. A watermark may be defined in a domain by specifying how it alters the host signal in that domain to effect the encoding of the watermark component. A frequency domain component alters the signal in the frequency domain, while a spatial domain component alters the signal in the spatial domain. Of course, such alterations may have an impact that extends across many transform domains.
While described here as watermark components, one can also construe the components to be different watermarks. This enables the watermark technology described throughout this document to be used in applications using two or more watermarks. For example, some copy protection applications of the watermark structure may use two or more watermarks, each performing similar or different function. One mark may be more fragile than another, and thus, disappear when the combined signal is corrupted or transformed in some fashion. The presence or lack of a watermark or watermark component conveys information to the detector to initiate or prohibit some action, such as playback, copying or recording of the marked signal.
A watermark system may include an embedder, detector, and reader. The watermark embedder encodes a watermark signal in a host signal to create a combined signal. The detector looks for the watermark signal in a potentially corrupted version of the combined signal, and computes its orientation. Finally, a reader extracts a message in the watermark signal from the combined signal using the orientation to approximate the original state of the combined signal.
There are a variety of alternative embodiments of the embedder and detector. One embodiment of the embedder performs error correction coding of a binary message, and then combines the binary message with a carrier signal to create a component of a watermark signal. It then combines the watermark signal with a host signal. To facilitate detection, it may also add a detection component to form a composite watermark signal having a message and detection component. The message component includes known or signature bits to facilitate detection, and thus, serves a dual function of identifying the mark and conveying a message. The detection component is designed to identify the orientation of the watermark in the combined signal, but may carry an information signal as well. For example, the signal values at selected locations in the detection component can be altered to encode a message.
One embodiment of the detector estimates an initial orientation of a watermark signal in the multidimensional signal, and refines the initial orientation to compute a refined orientation. As part of the process of refining the orientation, this detector computes at least one orientation parameter that increases correlation between the watermark signal and the multidimensional signal when the watermark or multidimensional signal is adjusted with the refined orientation.
Another detector embodiment computes orientation parameter candidates of a watermark signal in different portions of the target signal, and compares the similarity of orientation parameter candidates from the different portions. Based on this comparison, it determines which candidates are more likely to correspond to a valid watermark signal.
Yet another detector embodiment estimates orientation of the watermark in a target signal suspected of having a watermark. The detector then uses the orientation to extract a measure of the watermark in the target. It uses the measure of the watermark to assess merits of the estimated orientation. In one implementation, the measure of the watermark is the extent to which message bits read from the target signal match with expected bits. Another measure is the extent to which values of the target signal are consistent with the watermark signal. The measure of the watermark signal provides information about the merits of a given orientation that can be used to find a better estimate of the orientation.
One aspect of the disclosure is a method of detecting an embedded signal in a media signal. The method comprises receiving blocks of the media signal and computing a detection metric for the blocks. The detection metric comprises a measure of coincidence of detection parameters of different blocks. The method performs subsequent detection operations based on the measure of coincidence of the detection parameters.
Embodiments may be implemented in machine executable instructions, in hardware, firmware, or combinations thereof.
Further advantages and features of the embodiments will become apparent with reference to the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating an image watermark system.
FIG. 2 is a block diagram illustrating an image watermark embedder.
FIG. 3 is a spatial frequency domain plot of a detection watermark signal.
FIG. 4 is a flow diagram of a process for detecting a watermark signal in an image and computing its orientation within the image.
FIG. 5 is a flow diagram of a process reading a message encoded in a watermark.
FIG. 6 is a diagram depicting an example of a watermark detection process.
FIG. 7 is a diagram depicting the orientation of a transformed image superimposed over the original orientation of the image at the time of watermark encoding.
FIG. 8 is a diagram illustrating an implementation of a watermark embedder.
FIG. 9 is a diagram depicting an assignment map used to map raw bits in a message to locations within a host image.
FIG. 10 illustrates an example of a watermark orientation signal in a spatial frequency domain.
FIG. 11 illustrates the orientation signal shown in FIG. 10 in the spatial domain.
FIG. 12 is a diagram illustrating an overview of a watermark detector implementation.
FIG. 13 is a diagram illustrating an implementation of the detector pre-processor depicted generally in FIG. 12 .
FIG. 14 is a diagram illustrating a process for estimating rotation and scale vectors of a detection watermark signal.
FIG. 15 is a diagram illustrating a process for refining the rotation and scale vectors, and for estimating differential scale parameters of the detection watermark signal.
FIG. 16 is a diagram illustrating a process for aggregating evidence of the orientation signal and orientation parameter candidates from two or more frames.
FIG. 17 is a diagram illustrating a process for estimating translation parameters of the detection watermark signal.
FIG. 18 is a diagram illustrating a process for refining orientation parameters using known message bits in the watermark message.
FIG. 19 is a diagram illustrating a process for reading a watermark message from an image, after re-orienting the image data using an orientation vector.
FIG. 20 is a diagram of a computer system that serves as an operating environment for software implementations of a watermark embedder, detector and reader.
DETAILED DESCRIPTION
1.0 Introduction
A watermark can be viewed as an information signal that is embedded in a host signal, such as an image, audio, or some other media content. Watermarking systems based on the following detailed description may include the following components: 1) An embedder that inserts a watermark signal in the host signal to form a combined signal; 2) A detector that determines the presence and orientation of a watermark in a potentially corrupted version of the combined signal; and 3) A reader that extracts a watermark message from the combined signal. In some implementations, the detector and reader are combined.
The structure and complexity of the watermark signal can vary significantly, depending on the application. For example, the watermark may be comprised of one or more signal components, each defined in the same or different domains. Each component may perform one or more functions. Two primary functions include acting as an identifier to facilitate detection and acting as an information carrier to convey a message. In addition, components may be located in different spatial or temporal portions of the host signal, and may carry the same or different messages.
The host signal can vary as well. The host is typically some form of multi-dimensional media signal, such as an image, audio sequence or video sequence. In the digital domain, each of these media types is represented as a multi-dimensional array of discrete samples. For example, a color image has spatial dimensions (e.g., its horizontal and vertical components), and color space dimensions (e.g., YUV or RGB). Some signals, like video, have spatial and temporal dimensions. Depending on the needs of a particular application, the embedder may insert a watermark signal that exists in one or more of these dimensions.
In the design of the watermark and its components, developers are faced with several design issues such as: the extent to which the mark is impervious to jamming and manipulation (either intentional or unintentional); the extent of imperceptibility; the quantity of information content; the extent to which the mark facilitates detection and recovery, and the extent to which the information content can be recovered accurately.
For certain applications, such as copy protection or authentication, the watermark should be difficult to tamper with or remove by those seeking to circumvent it. To be robust, the watermark must withstand routine manipulation, such as data compression, copying, linear transformation, flipping, inversion, etc., and intentional manipulation intended to remove the mark or make it undetectable. Some applications require the watermark signal to remain robust through digital to analog conversion (e.g., printing an image or playing music), and analog to digital conversion (e.g., scanning the image or digitally sampling the music). In some cases, it is beneficial for the watermarking technique to withstand repeated watermarking.
A variety of signal processing techniques may be applied to address some or all of these design considerations. One such technique is referred to as spreading. Sometimes categorized as a spread spectrum technique, spreading is a way to distribute a message into a number of components (chips), which together make up the entire message. Spreading makes the mark more impervious to jamming and manipulation, and makes it less perceptible.
Another category of signal processing technique is error correction and detection coding. Error correction coding is useful to reconstruct the message accurately from the watermark signal. Error detection coding enables the decoder to determine when the extracted message has an error.
Another signal processing technique that is useful in watermark coding is called scattering. Scattering is a method of distributing the message or its components among an array of locations in a particular transform domain, such as a spatial domain or a spatial frequency domain. Like spreading, scattering makes the watermark less perceptible and more impervious to manipulation.
Yet another signal processing technique is gain control. Gain control is used to adjust the intensity of the watermark signal. The intensity of the signal impacts a number of aspects of watermark coding, including its perceptibility to the ordinary observer, and the ability to detect the mark and accurately recover the message from it.
Gain control can impact the various functions and components of the watermark differently. Thus, in some cases, it is useful to control the gain while taking into account its impact on the message and orientation functions of the watermark or its components. For example, in a watermark system described below, the embedder calculates a different gain for orientation and message components of an image watermark.
Another useful tool in watermark embedding and reading is perceptual analysis. Perceptual analysis refers generally to techniques for evaluating signal properties based on the extent to which those properties are (or are likely to be) perceptible to humans (e.g., listeners or viewers of the media content). A watermark embedder can take advantage of a Human Visual System (HVS) model to determine where to place a watermark and how to control the intensity of the watermark so that chances of accurately recovering the watermark are enhanced, resistance to tampering is increased, and perceptibility of the watermark is reduced. Such perceptual analysis can play an integral role in gain control because it helps indicate how the gain can be adjusted relative to the impact on the perceptibility of the mark. Perceptual analysis can also play an integral role in locating the watermark in a host signal. For example, one might design the embedder to hide a watermark in portions of a host signal that are more likely to mask the mark from human perception.
Various forms of statistical analyses may be performed on a signal to identify places to locate the watermark, and to identify places where to extract the watermark. For example, a statistical analysis can identify portions of a host image that have noise-like properties that are likely to make recovery of the watermark signal difficult. Similarly, statistical analyses may be used to characterize the host signal to determine where to locate the watermark.
Each of the techniques may be used alone, in various combinations, and in combination with other signal processing techniques.
In addition to selecting the appropriate signal processing techniques, the developer is faced with other design considerations. One consideration is the nature and format of the media content. In the case of digital images, for example, the image data is typically represented as an array of image samples. Color images are represented as an array of color vectors in a color space, such as RGB or YUV. The watermark may be embedded in one or more of the color components of an image. In some implementations, the embedder may transform the input image into a target color space, and then proceed with the embedding process in that color space.
2.0 Digital Watermark Embedder and Reader Overview
The following sections describe implementations of a watermark embedder and reader that operate on digital signals. The embedder encodes a message into a digital signal by modifying its sample values such that the message is imperceptible to the ordinary observer in output form. To extract the message, the reader captures a representation of the signal suspected of containing a watermark and then processes it to detect the watermark and decode the message.
FIG. 1 is a block diagram summarizing signal processing operations involved in embedding and reading a watermark. There are three primary inputs to the embedding process: the original, digitized signal 100 , the message 102 , and a series of control parameters 104 . The control parameters may include one or more keys. One key or set of keys may be used to encrypt the message. Another key or set of keys may be used to control the generation of a watermark carrier signal or a mapping of information bits in the message to positions in a watermark information signal.
The carrier signal or mapping of the message to the host signal may be encrypted as well. Such encryption may increase security by varying the carrier or mapping for different components of the watermark or watermark message. Similarly, if the watermark or watermark message is redundantly encoded throughout the host signal, one or more encryption keys can be used to scramble the carrier or signal mapping for each instance of the redundantly encoded watermark. This use of encryption provides one way to vary the encoding of each instance of the redundantly encoded message in the host signal. Other parameters may include control bits added to the message, and watermark signal attributes (e.g., orientation or other detection patterns) used to assist in the detection of the watermark.
Apart from encrypting or scrambling the carrier and mapping information, the embedder may apply different, and possibly unique carrier or mapping for different components of a message, for different messages, or from different watermarks or watermark components to be embedded in the host signal. For example, one watermark may be encoded in a block of samples with one carrier, while another, possibly different watermark, is encoded in a different block with a different carrier. A similar approach is to use different mappings in different blocks of the host signal.
The watermark embedding process 106 converts the message to a watermark information signal. It then combines this signal with the input signal and possibly another signal (e.g., an orientation pattern) to create a watermarked signal 108 . The process of combining the watermark with the input signal may be a linear or non-linear function. Examples of watermarking functions include: S*=S+gX; S*=S(1+gX); and S*=Se gX ; where S* is the watermarked signal vector, S is the input signal vector, and g is a function controlling watermark intensity. The watermark may be applied by modulating signal samples S in the spatial, temporal or some other transform domain.
To encode a message, the watermark encoder analyzes and selectively adjusts the host signal to give it attributes that correspond to the desired message symbol or symbols to be encoded. There are many signal attributes that may encode a message symbol, such as a positive or negative polarity of signal samples or a set of samples, a given parity (odd or even), a given difference value or polarity of the difference between signal samples (e.g., a difference between selected spatial intensity values or transform coefficients), a given distance value between watermarks, a given phase or phase offset between different watermark components, a modulation of the phase of the host signal, a modulation of frequency coefficients of the host signal, a given frequency pattern, a given quantizer (e.g., in Quantization Index Modulation) etc.
Some processes for combining the watermark with the input signal are termed non-linear, such as processes that employ dither modulation, modify least significant bits, or apply quantization index modulation. One type of non-linear modulation is where the embedder sets signal values so that they have some desired value or characteristic corresponding to a message symbol. For example, the embedder may designate that a portion of the host signal is to encode a given bit value. It then evaluates a signal value or set of values in that portion to determine whether they have the attribute corresponding to the message bit to be encoded. Some examples of attributes include a positive or negative polarity, a value that is odd or even, a checksum, etc. For example, a bit value may be encoded as a one or zero by quantizing the value of a selected sample to be even or odd. As another example, the embedder might compute a checksum or parity of an N bit pixel value or transform coefficient and then set the least significant bit to the value of the checksum or parity. Of course, if the signal already corresponds to the desired message bit value, it need not be altered. The same approach can be extended to a set of signal samples where some attribute of the set is adjusted as necessary to encode a desired message symbol. These techniques can be applied to signal samples in a transform domain (e.g., transform coefficients) or samples in the temporal or spatial domains.
Quantization index modulation techniques employ a set of quantizers. In these techniques, the message to be transmitted is used as an index for quantizer selection. In the decoding process, a distance metric is evaluated for all quantizers and the index with the smallest distance identifies the message value.
The watermark detector 110 operates on a digitized signal suspected of containing a watermark. As depicted generally in FIG. 1 , the suspect signal may undergo various transformations 112 , such as conversion to and from an analog domain, cropping, copying, editing, compression/decompression, transmission etc. Using parameters 114 from the embedder (e.g., orientation pattern, control bits, key(s)), it performs a series of correlation or other operations on the captured image to detect the presence of a watermark. If it finds a watermark, it determines its orientation within the suspect signal.
Using the orientation, if necessary, the reader 116 extracts the message. Some implementations do not perform correlation, but instead, use some other detection process or proceed directly to extract the watermark signal. For instance in some applications, a reader may be invoked one or more times at various temporal or spatial locations in an attempt to read the watermark, without a separate pre-processing stage to detect the watermark's orientation.
Some implementations require the original, un-watermarked signal to decode a watermark message, while others do not. In those approaches where the original signal is not necessary, the original un-watermarked signal can still be used to improve the accuracy of message recovery. For example, the original signal can be removed, leaving a residual signal from which the watermark message is recovered. If the decoder does not have the original signal, it can still attempt to remove portions of it (e.g., by filtering) that are expected not to contain the watermark signal.
Watermark decoder implementations use known relationships between a watermark signal and a message symbol to extract estimates of message symbol values from a signal suspected of containing a watermark. The decoder has knowledge of the properties of message symbols and how and where they are encoded into the host signal to encode a message. For example, it knows how message bit values of one and a zero are encoded and it knows where these message bits are originally encoded. Based on this information, it can look for the message properties in the watermarked signal. For example, it can test the watermarked signal to see if it has attributes of each message symbol (e.g., a one or zero) at a particular location and generate a probability measure as an indicator of the likelihood that a message symbol has been encoded. Knowing the approximate location of the watermark in the watermarked signal, the reader implementation may compare known message properties with the properties of the watermarked signal to estimate message values, even if the original signal is unavailable. Distortions to the watermarked signal and the host signal itself make the watermark difficult to recover, but accurate recovery of the message can be enhanced using a variety of techniques, such as error correction coding, watermark signal prediction, redundant message encoding, etc.
One way to recover a message value from a watermarked signal is to perform correlation between the known message property of each message symbol and the watermarked signal. If the amount of correlation exceeds a threshold, for example, then the watermarked signal may be assumed to contain the message symbol. The same process can be repeated for different symbols at various locations to extract a message. A symbol (e.g., a binary value of one or zero) or set of symbols may be encoded redundantly to enhance message recovery.
In some cases, it is useful to filter the watermarked signal to remove aspects of the signal that are unlikely to be helpful in recovering the message and/or are likely to interfere with the watermark message. For example, the decoder can filter out portions of the original signal and another watermark signal or signals. In addition, when the original signal is unavailable, the reader can estimate or predict the original signal based on properties of the watermarked signal. The original or predicted version of the original signal can then be used to recover an estimate of the watermark message. One way to use the predicted version to recover the watermark is to remove the predicted version before reading the desired watermark. Similarly, the decoder can predict and remove un-wanted watermarks or watermark components before reading the desired watermark in a signal having two or more watermarks.
2.1 Image Watermark Embedder
FIG. 2 is a block diagram illustrating an implementation of an exemplary embedder in more detail. The embedding process begins with the message 200 . As noted above, the message is binary number suitable for conversion to a watermark signal. For additional security, the message, its carrier, and the mapping of the watermark to the host signal may be encrypted with an encryption key 202 . In addition to the information conveyed in the message, the embedder may also add control bit values (“signature bits”) to the message to assist in verifying the accuracy of a read operation. These control bits, along with the bits representing the message, are input to an error correction coding process 204 designed to increase the likelihood that the message can be recovered accurately in the reader.
There are several alternative error correction coding schemes that may be employed. Some examples include BCH, convolution, Reed Solomon and turbo codes. These forms of error correction coding are sometimes used in communication applications where data is encoded in a carrier signal that transfers the encoded data from one place to another. In the digital watermarking application discussed here, the raw bit data is encoded in a fundamental carrier signal.
In addition to the error correction coding schemes mentioned above, the embedder and reader may also use a Cyclic Redundancy Check (CRC) to facilitate detection of errors in the decoded message data.
The error correction coding function 204 produces a string of bits, termed raw bits 206 , that are embedded into a watermark information signal. Using a carrier signal 208 and an assignment map 210 , the illustrated embedder encodes the raw bits in a watermark information signal 212 , 214 . In some applications, the embedder may encode a different message in different locations of the signal. The carrier signal may be a noise image. For each raw bit, the assignment map specifies the corresponding image sample or samples that will be modified to encode that bit.
The embedder depicted in FIG. 2 operates on blocks of image data (referred to as ‘tiles’) and replicates a watermark in each of these blocks. As such, the carrier signal and assignment map both correspond to an image block of a pre-determined size, namely, the size of the tile. To encode each bit, the embedder applies the assignment map to determine the corresponding image samples in the block to be modified to encode that bit. Using the map, it finds the corresponding image samples in the carrier signal. For each bit, the embedder computes the value of image samples in the watermark information signal as a function of the raw bit value and the value(s) of the corresponding samples in the carrier signal.
To illustrate the embedding process further, it is helpful to consider an example. First, consider the following background. Digital watermarking processes are sometimes described in terms of the transform domain in which the watermark signal is defined. The watermark may be defined in the spatial or temporal domain, or some other transform domain such as a wavelet transform, Discrete Cosine Transform (DCT), Discrete Fourier Transform (DFT), Hadamard transform, Hartley transform, Karhunen-Loeve transform (KLT) domain, etc.
Consider an example where the watermark is defined in a transform domain (e.g., a frequency domain such as DCT, wavelet or DFT). The embedder segments the image in the spatial domain into rectangular tiles and transforms the image samples in each tile into the transform domain. For example in the DCT domain, the embedder segments the image into N by N blocks and transforms each block into an N by N block of DCT coefficients. In this example, the assignment map specifies the corresponding sample location or locations in the frequency domain of the tile that correspond to a bit position in the raw bits. In the frequency domain, the carrier signal looks like a noise pattern. Each image sample in the frequency domain of the carrier signal is used together with a selected raw bit value to compute the value of the image sample at the location in the watermark information signal.
Now consider an example where the watermark is defined in the spatial domain. The embedder segments the image in the spatial domain into rectangular tiles of image samples (i.e. pixels). In this example, the assignment map specifies the corresponding sample location or locations in the tile that correspond to each bit position in the raw bits. In the spatial domain, the carrier signal looks like a noise pattern extending throughout the tile. Each image sample in the spatial domain of the carrier signal is used together with a selected raw bit value to compute the value of the image sample at the same location in the watermark information signal.
With this background, the embedder proceeds to encode each raw bit in the selected transform domain as follows. It uses the assignment map to look up the position of the corresponding image sample (or samples) in the carrier signal. The image sample value at that position in the carrier controls the value of the corresponding position in the watermark information signal. In particular, the carrier sample value indicates whether to invert the corresponding watermark sample value. The raw bit value is either a one or zero. Disregarding for a moment the impact of the carrier signal, the embedder adjusts the corresponding watermark sample upward to represent a one, or downward to represent a zero. Now, if the carrier signal indicates that the corresponding sample should be inverted, the embedder adjusts the watermark sample downward to represent a one, and upward to represent a zero. In this manner, the embedder computes the value of the watermark samples for a raw bit using the assignment map to find the spatial location of those samples within the block.
From this example, a number of points can be made. First, the embedder may perform a similar approach in any other transform domain. Second, for each raw bit, the corresponding watermark sample or samples are some function of the raw bit value and the carrier signal value. The specific mathematical relationship between the watermark sample, on one hand, and the raw bit value and carrier signal, on the other, may vary with the implementation. For example, the message may be convolved with the carrier, multiplied with the carrier, added to the carrier, or applied based on another non-linear function. Third, the carrier signal may remain constant for a particular application, or it may vary from one message to another. For example, a secret key may be used to generate the carrier signal. For each raw bit, the assignment map may define a pattern of watermark samples in the transform domain in which the watermark is defined. An assignment map that maps a raw bit to a sample location or set of locations (i.e. a map to locations in a frequency or spatial domain) is just one special case of an assignment map for a transform domain. Fourth, the assignment map may remain constant, or it may vary from one message to another. In addition, the carrier signal and map may vary depending on the nature of the underlying image. In sum, there many possible design choices within the implementation framework described above.
The embedder depicted in FIG. 2 combines another watermark component, shown as the detection watermark 216 , with the watermark information signal to compute the final watermark signal. The detection watermark is specifically chosen to assist in identifying the watermark and computing its orientation in a detection operation.
FIG. 3 is a spatial frequency plot illustrating one quadrant of a detection watermark. The points in the plot represent impulse functions indicating signal content of the detection watermark signal. The pattern of impulse functions for the illustrated quadrant is replicated in all four quadrants. There are a number of properties of the detection pattern that impact its effectiveness for a particular application. The selection of these properties is highly dependent on the application. One property is the extent to which the pattern is symmetric about one or more axes. For example, if the detection pattern is symmetrical about the horizontal and vertical axes, it is referred to as being quad symmetric. If it is further symmetrical about diagonal axes at an angle of 45 degrees, it is referred to as being octally symmetric (repeated in a symmetric pattern 8 times about the origin). Such symmetry aids in identifying the watermark in an image, and aids in extracting the rotation angle. However, in the case of an octally symmetric pattern, the detector includes an additional step of testing which of the four quadrants the orientation angle falls into.
Another criterion is the position of the impulse functions and the frequency range that they reside in. Preferably, the impulse functions fall in a mid frequency range. If they are located in a low frequency range, they may be noticeable in the watermarked image. If they are located in the high frequency range, they are more difficult to recover. Also, they should be selected so that scaling, rotation, and other manipulations of the watermarked signal do not push the impulse functions outside the range of the detector. Finally, the impulse functions should preferably not fall on the vertical or horizontal axes, and each impulse function should have a unique horizontal and vertical location. While the example depicted in FIG. 3 shows that some of the impulse functions fall on the same horizontal axis, it is trivial to alter the position of the impulse functions such that each has a unique vertical or horizontal coordinate.
Returning to FIG. 2 , the embedder makes a perceptual analysis 218 of the input image 220 to identify portions of the image that can withstand more watermark signal content without substantially impacting image fidelity. Generally, the perceptual analysis employs a HVS model to identify signal frequency bands and/or spatial areas to increase or decrease watermark signal intensity to make the watermark imperceptible to an ordinary observer. One type of model is to increase watermark intensity in frequency bands and spatial areas where there is more image activity. In these areas, the sample values are changing more than other areas and have more signal strength. The output of the perceptual analysis is a perceptual mask 222 . The mask may be implemented as an array of functions, which selectively increase the signal strength of the watermark signal based on a HVS model analysis of the input image. The mask may selectively increase or decrease the signal strength of the watermark signal in areas of greater signal activity.
The embedder combines ( 224 ) the watermark information, the detection signal and the perceptual mask to yield the watermark signal 226 . Finally, it combines ( 228 ) the input image 220 and the watermark signal 226 to create the watermarked image 230 . In the frequency domain watermark example above, the embedder combines the transform domain coefficients in the watermark signal to the corresponding coefficients in the input image to create a frequency domain representation of the watermarked image. It then transforms the image into the spatial domain. As an alternative, the embedder may be designed to convert the watermark into the spatial domain, and then add it to the image.
In the spatial watermark example above, the embedder combines the image samples in the watermark signal to the corresponding samples in the input image to create the watermarked image 230 .
The embedder may employ an invertible or non-invertible, and linear or non-linear function to combine the watermark signal and the input image (e.g., linear functions such as S*=S+gX; or S*=S(1+gX), convolution, quantization index modulation). The net effect is that some image samples in the input image are adjusted upward, while others are adjusted downward. The extent of the adjustment is greater in areas or subbands of the image having greater signal activity.
2.2. Overview of a Detector and Reader
FIG. 4 is a flow diagram illustrating an overview of a watermark detection process. This process analyzes image data 400 to search for an orientation pattern of a watermark in an image suspected of containing the watermark (the target image). First, the detector transforms the image data to another domain 402 , namely the spatial frequency domain, and then performs a series of correlation or other detection operations 404 . The correlation operations match the orientation pattern with the target image data to detect the presence of the watermark and its orientation parameters 406 (e.g., translation, scale, rotation, and differential scale relative to its original orientation). Finally, it re-orients the image data based on one or more of the orientation parameters 408 .
If the orientation of the watermark is recovered, the reader extracts the watermark information signal from the image data (optionally by first re-orienting the data based on the orientation parameters). FIG. 5 is flow diagram illustrating a process of extracting a message from re-oriented image data 500 . The reader scans the image samples (e.g., pixels or transform domain coefficients) of the re-oriented image ( 502 ), and uses known attributes of the watermark signal to estimate watermark signal values 504 . Recall that in one example implementation described above, the embedder adjusted sample values (e.g., frequency coefficients, color values, etc.) up or down to embed a watermark information signal. The reader uses this attribute of the watermark information signal to estimate its value from the target image. Prior to making these estimates, the reader may filter the image to remove portions of the image signal that may interfere with the estimating process. For example, if the watermark signal is expected to reside in low or medium frequency bands, then high frequencies may be filtered out.
In addition, the reader may predict the value of the original un-watermarked image to enhance message recovery. One form of prediction uses temporal or spatial neighbors to estimate a sample value in the original image. In the frequency domain, frequency coefficients of the original signal can be predicted from neighboring frequency coefficients in the same frequency subband. In video applications for example, a frequency coefficient in a frame can be predicted from spatially neighboring coefficients within the same frame, or temporally neighboring coefficients in adjacent frames or fields. In the spatial domain, intensity values of a pixel can be estimated from intensity values of neighboring pixels. Having predicted the value of a signal in the original, un-watermarked image, the reader then estimates the watermark signal by calculating an inverse of the watermarking function used to combine the watermark signal with the original signal.
For such watermark signal estimates, the reader uses the assignment map to find the corresponding raw bit position and image sample in the carrier signal ( 506 ). The value of the raw bit is a function of the watermark signal estimate, and the carrier signal at the corresponding location in the carrier. To estimate the raw bit value, the reader solves for its value based on the carrier signal and the watermark signal estimate. As reflected generally in FIG. 5 ( 508 ), the result of this computation represents only one estimate to be analyzed along with other estimates impacting the value of the corresponding raw bit. Some estimates may indicate that the raw bit is likely to be a one, while others may indicate that it is a zero. After the reader completes its scan, it compiles the estimates for each bit position in the raw bit string, and makes a determination of the value of each bit at that position ( 510 ). Finally, it performs the inverse of the error correction coding scheme to construct the message ( 512 ). In some implementations, probabilistic models may be employed to determine the likelihood that a particular pattern of raw bits is just a random occurrence rather than a watermark.
2.2.1 Example Illustrating Detector Process
FIG. 6 is a diagram depicting an example of a watermark detection process. The detector segments the target image into blocks (e.g., 600 , 602 ) and then performs a 2-dimensional fast fourier transform (2D FFT) on several blocks. This process yields 2D transforms of the magnitudes of the image contents of the blocks in the spatial frequency domain as depicted in the plot 604 shown in FIG. 6 .
Next, the detector process performs a log polar remapping of each transformed block. The detector may add some of the blocks together to increase the watermark signal to noise ratio. The type of remapping in this implementation is referred to as a Fourier Mellin transform. The Fourier Mellin transform is a geometric transform that warps the image data from a frequency domain to a log polar coordinate system. As depicted in the plot 606 shown in FIG. 6 , this transform sweeps through the transformed image data along a line at angle θ, mapping the data to a log polar coordinate system shown in the next plot 608 . The log polar coordinate system has a rotation axis, representing the angle θ, and a scale axis. Inspecting the transformed data at this stage, one can see the orientation pattern of the watermark begin to be distinguishable from the noise component (i.e., the image signal).
Next, the detector performs a correlation 610 between the transformed image block and the transformed orientation pattern 612 . At a high level, the correlation process slides the orientation pattern over the transformed image (in a selected transform domain, such as a spatial frequency domain) and measures the correlation at an array of discrete positions. Each such position has a corresponding scale and rotation parameter associated with it. Ideally, there is a position that clearly has the highest correlation relative to all of the others. In practice, there may be several candidates with a promising measure of correlation. As explained further below, these candidates may be subjected to one or more additional correlation stages to select the one that provides the best match.
There are a variety of ways to implement the correlation process. Any number of generalized matching filters may be implemented for this purpose. One such filter performs an FFT on the target and the orientation pattern, and multiplies the resulting arrays together to yield a multiplied FFT. Finally, it performs an inverse FFT on the multiplied FFT to return the data into its original log-polar domain. The position or positions within this resulting array with the highest magnitude represent the candidates with the highest correlation.
When there are several viable candidates, the detector can select a set of the top candidates and apply an additional correlation stage. Each candidate has a corresponding rotation and scale parameter. The correlation stage rotates and scales the FFT of the orientation pattern and performs a matching operation with the rotated and scaled pattern on the FFT of the target image. The matching operation multiplies the values of the transformed pattern with sample values at corresponding positions in the target image and accumulates the result to yield a measure of the correlation. The detector repeats this process for each of the candidates and picks the one with the highest measure of correlation. As shown in FIG. 6 , the rotation and scale parameters ( 614 ) of the selected candidate are then used to find additional parameters that describe the orientation of the watermark in the target image.
The detector applies the scale and rotation to the target data block 616 and then performs another correlation process between the orientation pattern 618 and the scaled and rotated data block 616 . The correlation process 620 is a generalized matching filter operation. It provides a measure of correlation for an array of positions that each has an associated translation parameter (e.g., an x, y position). Again, the detector may repeat the process of identifying promising candidates (i.e. those that reflect better correlation relative to others) and using those in an additional search for a parameter or set of orientation parameters that provide a better measure of correlation.
At this point, the detector has recovered the following orientation parameters: rotation, scale and translation. For many applications, these parameters may be sufficient to enable accurate reading of the watermark. In the read operation, the reader applies the orientation parameters to re-orient the target image and then proceeds to extract the watermark signal.
In some applications, the watermarked image may be stretched more in one spatial dimension than another. This type of distortion is sometimes referred to as differential scale or shear. Consider that the original image blocks are square. As a result of differential scale, each square may be warped into a parallelogram with unequal sides. Differential scale parameters define the nature and extent of this stretching.
There are several alternative ways to recover the differential scale parameters. One general class of techniques is to use the known parameters (e.g., the computed scale, rotation, and translation) as a starting point to find the differential scale parameters. Assuming the known parameters to be valid, this approach warps either the orientation pattern or the target image with selected amounts of differential scale and picks the differential scale parameters that yield the best correlation.
Another approach to determination of differential scale is set forth in application Ser. No. 09/452,022 (filed Nov. 30, 1999, now U.S. Pat. No. 6,959,098).
2.2.2 Example Illustrating Reader Process
FIG. 7 is a diagram illustrating a re-oriented image 700 superimposed onto the original watermarked image 702 . The difference in orientation and scale shows how the image was transformed and edited after the embedding process. The original watermarked image is sub-divided into tiles (e.g., pixel blocks 704 , 706 , etc.). When superimposed on the coordinate system of the original image 702 shown in FIG. 7 , the target image blocks typically do not match the orientation of the original blocks.
The reader scans samples of the re-oriented image data, estimating the watermark information signal. It estimates the watermark information signal, in part, by predicting original sample values of the un-watermarked image. The reader then uses an inverted form of the watermarking function to estimate the watermark information signal from the watermarked signal and the predicted signal. This inverted watermarking function expresses the estimate of the watermark signal as a function of the predicted signal and the watermarked signal. Having an estimate of the watermark signal, it then uses the known relationship among the carrier signal, the watermark signal, and the raw bit to compute an estimate of the raw bit. Recall that samples in the watermark information signal are a function of the carrier signal and the raw bit value. Thus, the reader may invert this function to solve for an estimate of the raw bit value.
Recall that the embedder implementation discussed in connection with FIG. 2 redundantly encodes the watermark information signal in blocks of the input signal. Each raw bit may map to several samples within a block. In addition, the embedder repeats a mapping process for each of the blocks. As such, the reader generates several estimates of the raw bit value as it scans the watermarked image.
The information encoded in the raw bit string can be used to increase the accuracy of read operations. For instance, some of the raw bits act as signature bits that perform a validity checking function. Unlike unknown message bits, the reader knows the expected values of these signature bits. The reader can assess the validity of a read operation based on the extent to which the extracted signature bit values match the expected signature bit values. The estimates for a given raw bit value can then be given a higher weight depending on whether they are derived from a tile with a greater measure of validity.
3.0 Embedder Implementation
The following sections describe an implementation of the digital image watermark embedder depicted in FIG. 8 . The embedder inserts two watermark components into the host image: a message component and a detection component (called the orientation pattern). The message component is defined in a spatial domain or other transform domain, while the orientation pattern is defined in a frequency domain. As explained later, the message component serves a dual function of conveying a message and helping to identify the watermark location in the image.
The embedder inserts the watermark message and orientation pattern in blocks of a selected color plane or planes (e.g., luminance or chrominance plane) of the host image. The message payload varies from one application to another, and can range from a single bit to the number of image samples in the domain in which it is embedded. The blocks may be blocks of samples in a spatial domain or some other transform domain.
3.1 Encoding the Message
The embedder converts binary message bits into a series of binary raw bits that it hides in the host image. As part of this process, a message encoder 800 appends certain known bits to the message bits 802 . It performs an error detection process (e.g., parity, Cyclic Redundancy Check (CRC), etc.) to generate error detection bits and adds the error detection bits to the message. An error correction coding operation then generates raw bits from the combined known and message bit string.
For the error correction operation, the embedder may employ any of a variety of error correction codes such as Reed Solomon, BCH, convolution or turbo codes. The encoder may perform an M-ary modulation process on the message bits that maps groups of message bits to a message signal based on an M-ary symbol alphabet.
In one application of the embedder, the component of the message representing the known bits is encoded more redundantly than the other message bits. This is an example of a shorter message component having greater signal strength than a longer, weaker message component. The embedder gives priority to the known bits in this scheme because the reader uses them to verify that it has found the watermark in a potentially corrupted image, rather than a signal masquerading as the watermark.
3.2 Spread Spectrum Modulation
The embedder uses spread spectrum modulation as part of the process of creating a watermark signal from the raw bits. A spread spectrum modulator 804 spreads each raw bit into a number of “chips.” The embedder generates a pseudo random number that acts as the carrier signal of the message. To spread each raw bit, the modulator performs an exclusive OR (XOR) operation between the raw bit and each bit of a pseudo random binary number of a pre-determined length. The length of the pseudo random number depends, in part, on the size of the message and the image.
Preferably, the pseudo random number should contain roughly the same number of zeros and ones, so that the net effect of the raw bit on the host image block is zero. If a bit value in the pseudo random number is a one, the value of the raw bit is inverted. Conversely, if the bit value is a zero, then the value of the raw bit remains the same.
The length of the pseudorandom number may vary from one message bit or symbol to another. By varying the length of the number, some message bits can be spread more than others.
3.3 Scattering the Watermark Message
The embedder scatters each of the chips corresponding to a raw bit throughout an image block. An assignment map 806 assigns locations in the block to the chips of each raw bit. Each raw bit is spread over several chips. As noted above, an image block may represent a block of transform domain coefficients or samples in a spatial domain. The assignment map may be used to encode some message bits or symbols (e.g., groups of bits) more redundantly than others by mapping selected bits to more locations in the host signal than other message bits. In addition, it may be used to map different messages, or different components of the same message, to different locations in the host signal.
FIG. 9 depicts an example of the assignment map. Each of the blocks in FIG. 9 correspond to an image block and depict a pattern of chips corresponding to a single raw bit. FIG. 9 depicts a total of 32 example blocks. The pattern within a block is represented as black dots on a white background. Each of the patterns is mutually exclusive such that each raw bit maps to a pattern of unique locations relative to the patterns of every other raw bit. Though not a requirement, the combined patterns, when overlapped, cover every location within the image block.
3.4 Gain Control and Perceptual Analysis
To insert the information carried in a chip to the host image, the embedder alters the corresponding sample value in the host image. In particular, for a chip having a value of one, it adds to the corresponding sample value, and for a chip having a value of zero, it subtracts from the corresponding sample value. A gain controller in the embedder adjusts the extent to which each chip adds or subtracts from the corresponding sample value.
The gain controller takes into account the orientation pattern when determining the gain. It applies a different gain to the orientation pattern than to the message component of the watermark. After applying the gain, the embedder combines the orientation pattern and message components together to form the composite watermark signal, and combines the composite watermark with the image block. One way to combine these signal components is to add them, but other linear or non-linear functions may be used as well.
The orientation pattern is comprised of a pattern of quad symmetric impulse functions in the spatial frequency domain. In the spatial domain, these impulse functions look like cosine waves. An example of the orientation pattern is depicted in FIGS. 10 and 11 . FIG. 10 shows the impulse functions as points in the spatial frequency domain, while FIG. 11 shows the orientation pattern in the spatial domain. Before adding the orientation pattern component to the message component, the embedder may transform the watermark components to a common domain. For example, if the message component is in a spatial domain and the orientation component is in a frequency domain, the embedder transforms the orientation component to a common spatial domain before combining them together.
FIG. 8 depicts the gain controller used in the embedder. Note that the gain controller operates on the blocks of image samples 808 , the message watermark signal, and a global gain input 810 , which may be specified by the user. A perceptual analyzer component 812 of the gain controller performs a perceptual analysis on the block to identify samples that can tolerate a stronger watermark signal without substantially impacting visibility. In places where the naked eye is less likely to notice the watermark, the perceptual analyzer increases the strength of the watermark. Conversely, it decreases the watermark strength where the eye is more likely to notice the watermark.
The perceptual analyzer shown in FIG. 8 performs a series of filtering operations on the image block to compute an array of gain values. There are a variety of filters suitable for this task. These filters include an edge detector filter that identifies edges of objects in the image, a non-linear filter to map gain values into a desired range, and averaging or median filters to smooth the gain values. Each of these filters may be implemented as a series of one-dimensional filters (one operating on rows and the other on columns) or two-dimensional filters. The size of the filters (i.e. the number of samples processed to compute a value for a given location) may vary (e.g., 3 by 3, 5 by 5, etc.). The shape of the filters may vary as well (e.g., square, cross-shaped, etc.). The perceptual analyzer process produces a detailed gain multiplier. The multiplier is a vector with elements corresponding to samples in a block.
Another component 818 of the gain controller computes an asymmetric gain based on the output of the image sample values and message watermark signal. This component analyzes the samples of the block to determine whether they are consistent with the message signal. The embedder reduces the gain for samples whose values relative to neighboring values are consistent with the message signal.
The embedder applies the asymmetric gain to increase the chances of an accurate read in the watermark reader. To understand the effect of the asymmetric gain, it is helpful to explain the operation of the reader. The reader extracts the watermark message signal from the watermarked signal using a predicted version of the original signal. It estimates the watermark message signal value based on values of the predicted signal and the watermarked signal at locations of the watermarked signal suspected of containing a watermark signal. There are several ways to predict the original signal. One way is to compute a local average of samples around the sample of interest. The average may be computed by taking the average of vertically adjacent samples, horizontally adjacent samples, an average of samples in a cross-shaped filter (both vertical and horizontal neighbors, an average of samples in a square-shaped filter, etc. The estimate may be computed one time based on a single predicted value from one of these averaging computations. Alternatively, several estimates may be computed based on two or more of these averaging computations (e.g., one estimate for vertically adjacent samples and another for horizontally adjacent samples). In the latter case, the reader may keep estimates if they satisfy a similarity metric. In other words, the estimates are deemed valid if they within a predetermined value or have the same polarity.
Knowing this behavior of the reader, the embedder computes the asymmetric gain as follows. For samples that have values relative to their neighbors that are consistent with the watermark signal, the embedder reduces the asymmetric gain. Conversely, for samples that are inconsistent with the watermark signal, the embedder increases the asymmetric gain. For example, if the chip value is a one, then the sample is consistent with the watermark signal if its value is greater than its neighbors. Alternatively, if the chip value is a zero, then the sample is consistent with the watermark signal if its value is less than its neighbors.
Another component 820 of the gain controller computes a differential gain, which represents an adjustment in the message vs. orientation pattern gains. As the global gain increases, the embedder emphasizes the message gain over the orientation pattern gain by adjusting the global gain by an adjustment factor. The inputs to this process 820 include the global gain 810 and a message differential gain 822 . When the global gain is below a lower threshold, the adjustment factor is one. When the global gain is above an upper threshold, the adjustment factor is set to an upper limit greater than one. For global gains falling within the two thresholds, the adjustment factor increases linearly between one and the upper limit. The message differential gain is the product of the adjustment factor and the global gain.
At this point, there are four sources of gain: the detailed gain, the global gain, the asymmetric gain, and the message dependent gain. The embedder applies the first two gain quantities to both the message and orientation watermark signals. It only applies the latter two to the message watermark signal. FIG. 8 depicts how the embedder applies the gain to the two watermark components. First, it multiplies the detailed gain with the global gain to compute the orientation pattern gain. It then multiplies the orientation pattern gain with the adjusted message differential gain and asymmetric gain to form the composite message gain.
Finally, the embedder forms the composite watermark signal. It multiplies the composite message gain with the message signal, and multiplies the orientation pattern gain with the orientation pattern signal. It then combines the result in a common transform domain to get the composite watermark. The embedder applies a watermarking function to combine the composite watermark to the block to create a watermarked image block. The message and orientation components of the watermark may be combined by mapping the message bits to samples of the orientation signal, and modulating the samples of the orientation signal to encode the message.
The embedder computes the watermark message signal by converting the output of the assignment map 806 to delta values, indicating the extent to which the watermark signal changes the host signal. As noted above, a chip value of one corresponds to an upward adjustment of the corresponding sample, while a chip value of zero corresponds to a downward adjustment. The embedder specifies the specific amount of adjustment by assigning a delta value to each of the watermark message samples ( 830 ).
4.0 Detector Implementation
FIG. 12 illustrates an overview of a watermark detector that detects the presence of a detection watermark in a host image and its orientation. Using the orientation pattern and the known bits inserted in the watermark message, the detector determines whether a potentially corrupted image contains a watermark, and if so, its orientation in the image.
Recall that the composite watermark is replicated in blocks of the original image. After an embedder places the watermark in the original digital image, the watermarked image is likely to undergo several transformations, either from routine processing or from intentional tampering. Some of these transformations include: compression, decompression, color space conversion, digital to analog conversion, printing, scanning, analog to digital conversion, scaling, rotation, inversion, flipping differential scale, and lens distortion. In addition to these transformations, various noise sources can corrupt the watermark signal, such as fixed pattern noise, thermal noise, etc.
When building a detector implementation for a particular application, the developer may implement counter-measures to mitigate the impact of the types of transformations, distortions and noise expected for that application. Some applications may require more counter-measures than others. The detector described below is designed to recover a watermark from a watermarked image after the image has been printed, and scanned. The following sections describe the counter-measures to mitigate the impact of various forms of corruption. The developer can select from among these counter-measures when implementing a detector for a particular application.
For some applications, the detector will operate in a system that provides multiple image frames of a watermarked object. One typical example of such a system is a computer equipped with a digital camera. In such a configuration, the digital camera can capture a temporal sequence of images as the user or some device presents the watermarked image to the camera.
As shown in FIG. 12 , the principal components of the detector are: 1) pre-processor 900 ; 2) rotation and scale estimator 902 ; 3) orientation parameter refiner 904 ; 4) translation estimator 906 ; 5) translation refiner 908 ; and reader 910 .
The preprocessor 900 takes one or more frames of image data 912 and produces a set of image blocks 914 prepared for further analysis. The rotation-scale estimator 902 computes rotation-scale vectors 916 that estimate the orientation of the orientation signal in the image blocks. The parameter refiner 904 collects additional evidence of the orientation signal and further refines the rotation scale vector candidates by estimating differential scale parameters. The result of this refining stage is a set of 4D vectors candidates 918 (rotation, scale, and two differential scale parameters). The translation estimator 906 uses the 4D vector candidates to re-orient image blocks with promising evidence of the orientation signal. It then finds estimates of translation parameters 920 . The translation refiner 908 invokes the reader 910 to assess the merits of an orientation vector. When invoked by the detector, the reader uses the orientation vector to approximate the original orientation of the host image and then extracts values for the known bits in the watermark message. The detector uses this information to assess the merits of and refine orientation vector candidates.
By comparing the extracted values of the known bits with the expected values, the reader provides a figure of merit for an orientation vector candidate. The translation refiner then picks a 6D vector, including rotation, scale, differential scale and translation, that appears likely produce a valid read of the watermark message 922 . The following sections describe implementations of these components in more detail.
4.1 Detector Pre-Processing
FIG. 13 is a flow diagram illustrating preprocessing operations in the detector shown in FIG. 12 . The detector performs a series of pre-processing operations on the native image 930 to prepare the image data for further analysis. It begins by filling memory with one or more frames of native image data ( 932 ), and selecting sets of pixel blocks 934 from the native image data for further analysis ( 936 ). While the detector can detect a watermark using a single image frame, it also has support for detecting the watermark using additional image frames. As explained below, the use of multiple frames has the potential for increasing the chances of an accurate detection and read.
In applications where a camera captures an input image of a watermarked object, the detector may be optimized to address problems resulting from movement of the object. Typical PC cameras, for example, are capable of capturing images at a rate of at least 10 frames a second. A frustrated user might attempt to move the object in an attempt to improve detection. Rather than improving the chances of detection, the movement of the object changes the orientation of the watermark from one frame to the next, potentially making the watermark more difficult to detect. One way to address this problem is to buffer one or more frames, and then screen the frame or frames to determine if they are likely to contain a valid watermark signal. If such screening indicates that a frame is not likely to contain a valid signal, the detector can discard it and proceed to the next frame in the buffer, or buffer a new frame. Another enhancement is to isolate portions of a frame that are most likely to have a valid watermark signal, and then perform more detailed detection of the isolated portions.
After loading the image into the memory, the detector selects image blocks 934 for further analysis. It is not necessary to load or examine each block in a frame because it is possible to extract the watermark using only a portion of an image. The detector looks at only a subset of the samples in an image, and preferably analyzes samples that are more likely to have a recoverable watermark signal.
The detector identifies portions of the image that are likely to have the highest watermark signal to noise ratio. It then attempts to detect the watermark signal in the identified portions. In the context of watermark detection, the host image is considered to be a source of noise along with conventional noise sources. While it is typically not practical to compute the signal to noise ratio, the detector can evaluate attributes of the signal that are likely to evince a promising watermark signal to noise ratio. These properties include the signal activity (as measured by sample variance, for example), and a measure of the edges (abrupt changes in image sample values) in an image block. Preferably, the signal activity of a candidate block should fall within an acceptable range, and the block should not have a high concentration of strong edges. One way to quantify the edges in the block is to use an edge detection filter (e.g., a LaPlacian, Sobel, etc.).
In one implementation, the detector divides the input image into blocks, and analyzes each block based on pre-determined metrics. It then ranks the blocks according to these metrics. The detector then operates on the blocks in the order of the ranking The metrics include sample variance in a candidate block and a measure of the edges in the block. The detector combines these metrics for each candidate block to compute a rank representing the probability that it contains a recoverable watermark signal.
In another implementation, the detector selects a pattern of blocks and evaluates each one to try to make the most accurate read from the available data. In either implementation, the block pattern and size may vary. This particular implementation selects a pattern of overlapping blocks (e.g., a row of horizontally aligned, overlapping blocks). One optimization of this approach is to adaptively select a block pattern that increases the signal to noise ratio of the watermark signal. While shown as one of the initial operations in the preparation, the selection of blocks can be postponed until later in the pre-processing stage.
Next, the detector performs a color space conversion on native image data to compute an array of image samples in a selected color space for each block ( 936 ). In the following description, the color space is luminance, but the watermark may be encoded in one or more different color spaces. The objective is to get a block of image samples with lowest noise practical for the application. While the implementation currently performs a row by row conversion of the native image data into 8 bit integer luminance values, it may be preferable to convert to floating-point values for some applications. One optimization is to select a luminance converter that is adapted for the sensor used to capture the digital input image. For example, one might experimentally derive the lowest noise luminance conversion for commercially available sensors, e.g., CCD cameras or scanners, CMOS cameras, etc. Then, the detector could be programmed to select either a default luminance converter, or one tuned to a specific type of sensor.
At one or more stages of the detector, it may be useful to perform operations to mitigate the impact of noise and distortion. In the pre-processing phase, for example, it may be useful to evaluate fixed pattern noise and mitigate its effect ( 938 ). The detector may look for fixed pattern noise in the native input data or the luminance data, and then mitigate it.
One way to mitigate certain types of noise is to combine data from different blocks in the same frame, or corresponding blocks in different frames 940 . This process helps augment the watermark signal present in the blocks, while reducing the noise common to the blocks. For example, merely adding blocks together may mitigate the effects of common noise.
In addition to common noise, other forms of noise may appear in each of the blocks such as noise introduced in the printing or scanning processes. Depending on the nature of the application, it may be advantageous to perform common noise recognition and removal at this stage 942 . The developer may select a filter or series of filters to target certain types of noise that appear during experimentation with images. Certain types of median filters may be effective in mitigating the impact of spectral peaks (e.g., speckles) introduced in printing or scanning operations.
In addition to introducing noise, the printing and image capture processes may transform the color or orientation of the original, watermarked image. As described above, the embedder typically operates on a digital image in a particular color space and at a desired resolution. The watermark embedders normally operate on digital images represented in an RGB or CYMK color space at a desired resolution (e.g., 100 dpi or 300 dpi, the resolution at which the image is printed). The images are then printed on paper with a screen printing process that uses the CYMK subtractive color space at a line per inch (LPI) ranging from 65-200. 133 lines/in is typical for quality magazines and 73 lines/in is typical for newspapers. In order to produce a quality image and avoid pixelization, the rule of thumb is to use digital images with a resolution that is at least twice the press resolution. This is due to the half tone printing for color production. Also, different presses use screens with different patterns and line orientations and have different precision for color registration.
One way to counteract the transforms introduced through the printing process is to develop a model that characterizes these transforms and optimize watermark embedding and detecting based on this characterization. Such a model may be developed by passing watermarked and unwatermarked images through the printing process and observing the changes that occur to these images. The resulting model characterizes the changes introduced due to the printing process. The model may represent a transfer function that approximates the transforms due to the printing process. The detector then implements a pre-processing stage that reverses or at least mitigates the effect of the printing process on watermarked images. The detector may implement a pre-processing stage that performs the inverse of the transfer function for the printing process.
A related challenge is the variety in paper attributes used in different printing processes. Papers of various qualities, thickness and stiffness, absorb ink in various ways. Some papers absorb ink evenly, while others absorb ink at rates that vary with the changes in the paper's texture and thickness. These variations may degrade the embedded watermark signal when a digitally watermarked image is printed. The watermark process can counteract these effects by classifying and characterizing paper so that the embedder and reader can compensate for this printing-related degradation.
Variations in image capture processes also pose a challenge. In some applications, it is necessary to address problems introduced due to interlaced image data. Some video camera produce interlaced fields representing the odd or even scan lines of a frame. Problems arise when the interlaced image data consists of fields from two consecutive frames. To construct an entire frame, the preprocessor may combine the fields from consecutive frames while dealing with the distortion due to motion that occurs from one frame to the next. For example, it may be necessary to shift one field before interleaving it with another field to counteract inter-frame motion. A de-blurring function may be used to mitigate the blurring effect due to the motion between frames.
Another problem associated with cameras in some applications is blurring due to the lack of focus. The preprocessor can mitigate this effect by estimating parameters of a blurring function and applying a de-blurring function to the input image.
Yet another problem associated with cameras is that they tend to have color sensors that utilize different color pattern implementations. As such, a sensor may produce colors slightly different than those represented in the object being captured. Most CCD and CMOS cameras use an array of sensors to produce colored images. The sensors in the array are arranged in clusters of sensitive to three primary colors red, green, and blue according to a specific pattern. Sensors designated for a particular color are dyed with that color to increase their sensitivity to the designated color. Many camera manufacturers use a Bayer color pattern GR/BG. While this pattern produces good image quality, it causes color mis-registration that degrades the watermark signal. Moreover, the color space converter, which maps the signal from the sensors to another color space such as YUV or RGB, may vary from one manufacturer to another. One way to counteract the mis-registration of the camera's color pattern is to account for the distortion due to the pattern in a color transformation process, implemented either within the camera itself, or as a pre-processing function in the detector.
Another challenge in counteracting the effects of the image capture process is dealing with the different types of distortion introduced from various image capture devices. For example, cameras have different sensitivities to light. In addition, their lenses have different spherical distortion, and noise characteristics. Some scanners have poor color reproduction or introduce distortion in the image aspect ratio. Some scanners introduce aliasing and employ interpolation to increase resolution. The detector can counteract these effects in the pre-processor by using an appropriate inverse transfer function. An off-line process first characterizes the distortion of several different image capture devices (e.g., by passing test images through the scanner and deriving a transfer function modeling the scanner distortion). Some detectors may be equipped with a library of such inverse transfer functions from which they select one that corresponds to the particular image capture device
Yet another challenge in applications where the image is printed on paper and later scanned is that the paper deteriorates over time and degrades the watermark. Also, varying lighting conditions make the watermark difficult to detect. Thus, the watermark may be selected so as to be more impervious to expected deterioration, and recoverable over a wider range of lighting conditions.
At the close of the pre-processing stage, the detector has selected a set of blocks for further processing. It then proceeds to gather evidence of the orientation signal in these blocks, and estimate the orientation parameters of promising orientation signal candidates. Since the image may have suffered various forms of corruption, the detector may identify several parts of the image that appear to have attributes similar to the orientation signal. As such, the detector may have to resolve potentially conflicting and ambiguous evidence of the orientation signal. To address this challenge, the detector estimates orientation parameters, and then refines theses estimates to extract the orientation parameters that are more likely to evince a valid signal than other parameter candidates.
4.2 Estimating Initial Orientation Parameters
FIG. 14 is a flow diagram illustrating a process for estimating rotation-scale vectors. The detector loops over each image block ( 950 ), calculating rotation-scale vectors with the best detection values in each block. First, the detector filters the block in a manner that tends to amplify the orientation signal while suppressing noise, including noise from the host image itself ( 952 ). Implemented as a multi-axis LaPlacian filter, the filter highlights edges (e.g., high frequency components of the image) and then suppresses them. The term, “multi-axis,” means that the filter includes a series of stages that each operates on particular axis. First, the filter operates on the rows of luminance samples, then operates on the columns, and adds the results. The filter may be applied along other axes as well. Each pass of the filter produces values at discrete levels. The final result is an array of samples, each having one of five values: {−2, −1, 0, 1, 2}.
Next, the detector performs a windowing operation on the block data to prepare it for an FFT transform ( 954 ). This windowing operation provides signal continuity at the block edges. The detector then performs an FFT ( 956 ) on the block, and retains only the magnitude component ( 958 ).
In an alternative implementation, the detector may use the phase signal produced by the FFT to estimate the translation parameter of the orientation signal. For example, the detector could use the rotation and scale parameters extracted in the process described below, and then compute the phase that provided the highest measure of correlation with the orientation signal using the phase component of the FFT process.
After computing the FFT, the detector applies a Fourier magnitude filter ( 960 ) on the magnitude components. The filter in the implementation slides over each sample in the Fourier magnitude array and filters the sample's eight neighbors in a square neighborhood centered at the sample. The filter boosts values representing a sharp peak with a rapid fall-off, and suppresses the fall-off portion. It also performs a threshold operation to clip peaks to an upper threshold.
Next, the detector performs a log-polar re-sample ( 962 ) of the filtered Fourier magnitude array to produce a log-polar array 964 . This type of operation is sometimes referred to as a Fourier Mellin transform. The detector, or some off-line pre-processor, performs a similar operation on the orientation signal to map it to the log-polar coordinate system. Using matching filters, the detector implementation searches for a orientation signal in a specified window of the log-polar coordinate system. For example, consider that the log-polar coordinate system is a two dimensional space with the scale being the vertical axis and the angle being the horizontal axis. The window ranges from 0 to 90 degrees on the horizontal axis and from approximately 50 to 2400 dpi on the vertical axis. Note that the orientation pattern should be selected so that routine scaling does not push the orientation pattern out of this window. The orientation pattern can be designed to mitigate this problem, as noted above, and as explained in co-pending patent application No. 60/136,572, filed May 28, 1999, by Ammon Gustafson, entitled Watermarking System With Improved Technique for Detecting Scaling and Rotation, filed May 28, 1999.
The detector proceeds to correlate the orientation and the target signal in the log polar coordinate system. As shown in FIG. 14 , the detector uses a generalized matched filter GMF ( 966 ). The GMF performs an FFT on the orientation and target signal, multiplies the resulting Fourier domain entities, and performs an inverse FFT. This process yields a rectangular array of values in log-polar coordinates, each representing a measure of correlation and having a corresponding rotation angle and scale vector. As an optimization, the detector may also perform the same correlation operations for distorted versions ( 968 , 970 , 972 ) of the orientation signal to see if any of the distorted orientation patterns results in a higher measure of correlation. For example, the detector may repeat the correlation operation with some pre-determined amount of horizontal and vertical differential distortion ( 970 , 972 ). The result of this correlation process is an array of correlation values 974 specifying the amount of correlation that each corresponding rotation-scale vector provides.
The detector processes this array to find the top M peaks and their location in the log-polar space 976 . To extract the location more accurately, the detector uses interpolation to provide the inter-sample location of each of the top peaks 978 . The interpolator computes the 2D median of the samples around a peak and provides the location of the peak center to an accuracy of 0.1 sample.
The detector proceeds to rank the top rotation-scale vectors based on yet another correlation process 980 . In particular, the detector performs a correlation between a Fourier magnitude representation for each rotation-scale vector candidate and a Fourier magnitude specification of the orientation signal 982 . Each Fourier magnitude representation is scaled and rotated by an amount reflected by the corresponding rotation-scale vector. This correlation operation sums a point-wise multiplication of the orientation pattern impulse functions in the frequency domain with the Fourier magnitude values of the image at corresponding frequencies to compute a measure of correlation for each peak 984 . The detector then sorts correlation values for the peaks ( 986 ).
Finally, the detector computes a detection value for each peak ( 988 ). It computes the detection value by quantizing the correlation values. Specifically, it computes a ratio of the peak's correlation value and the correlation value of the next largest peak. Alternatively, the detector may compute the ratio of the peak's correlation value and a sum or average of the correlation values of the next n highest peaks, where n is some predetermined number. Then, the detector maps this ratio to a detection value based on a statistical analysis of unmarked images.
The statistical analysis plots a distribution of peak ratio values found in unmarked images. The ratio values are mapped to a detection value based on the probability that the value came from an unmarked image. For example, 90% of the ratio values in unmarked images fall below a first threshold T 1 , and thus, the detection value mapping for a ratio of T 1 is set to 1. Similarly, 99% of the ratio values in unmarked images fall below T 2 , and therefore, the detection value is set to 2. 99.9% of the ratio values in unmarked images fall below T 3 , and the corresponding detection value is set to 3. The threshold values, T 1 , T 2 and T 3 , may be determined by performing a statistical analysis of several images. The mapping of ratios to detection values based on the statistical distribution may be implemented in a look up table.
The statistical analysis may also include a maximum likelihood analysis. In such an analysis, an off-line detector generates detection value statistics for both marked and unmarked images. Based on the probability distributions of marked and unmarked images, it determines the likelihood that a given detection value for an input image originates from a marked and unmarked image.
At the end of these correlation stages, the detector has computed a ranked set of rotation-scale vectors 990 , each with a quantized measure of correlation associated with it. At this point, the detector could simply choose the rotation and scale vectors with the highest rank and proceed to compute other orientation parameters, such as differential scale and translation. Instead, the detector gathers more evidence to refine the rotation-scale vector estimates. FIG. 15 is a flow diagram illustrating a process for refining the orientation parameters using evidence of the orientation signal collected from blocks in the current frame.
Continuing in the current frame, the detector proceeds to compare the rotation and scale parameters from different blocks (e.g., block 0 , block 1 , block 2 ; 1000 , 1002 , and 1004 in FIG. 15 ). In a process referred to as interblock coincidence matching 1006 , it looks for similarities between rotation-scale parameters that yielded the highest correlation in different blocks. To quantify this similarity, it computes the geometric distance between each peak in one block with every other peak in the other blocks. It then computes the probability that peaks will fall within this calculated distance. There are a variety of ways to calculate the probability. In one implementation, the detector computes the geometric distance between two peaks, computes the circular area encompassing the two peaks (π(geometric distance) 2 ), and computes the ratio of this area to the total area of the block. Finally, it quantizes this probability measure for each pair of peaks ( 1008 ) by computing the log (base 10) of the ratio of the total area over the area encompassing the two peaks. At this point, the detector has calculated two detection values: quantized peak value, and the quantized distance metric.
The detector now forms multi-block grouping of rotation-scale vectors and computes a combined detection value for each grouping ( 1010 ). The detector groups vectors based on their relative geometric proximity within their respective blocks. It then computes the combined detection value by combining the detection values of the vectors in the group ( 1012 ). One way to compute a combined detection value is to add the detection values or add a weighted combination of them.
Having calculated the combined detection values, the detector sorts each grouping by its combined detection value ( 1014 ). This process produces a set of the top groupings of unrefined rotation-scale candidates, ranked by detection value 1016 . Next, the detector weeds out rotation-scale vectors that are not promising by excluding those groupings whose combined detection values are below a threshold (the “refine threshold” 1018 ). The detector then refines each individual rotation-scale vector candidate within the remaining groupings.
The detector refines a rotation-scale vector by adjusting the vector and checking to see whether the adjustment results in a better correlation. As noted above, the detector may simply pick the best rotation-scale vector based on the evidence collected thus far, and refine only that vector. An alternative approach is to refine each of the top rotation-scale vector candidates, and continue to gather evidence for each candidate. In this approach, the detector loops over each vector candidate ( 1020 ), refining each one.
One approach of refining the orientation vector is as follows:
fix the orientation signal impulse functions (“points”) within a valid boundary ( 1022 ); pre-refine the rotation-scale vector ( 1024 ); find the major axis and re-fix the orientation points ( 1026 ); and refine each vector with the addition of a differential scale component ( 1028 ).
In this approach, the detector pre-refines a rotation-scale vector by incrementally adjusting one of the parameters (scale, rotation angle), adjusting the orientation points, and then summing a point-wise multiplication of the orientation pattern and the image block in the Fourier magnitude domain. The refiner compares the resulting measure of correlation with previous measures and continues to adjust one of the parameters so long as the correlation increases. After refining the scale and rotation angle parameters, the refiner finds the major axis, and re-fixes the orientation points. It then repeats the refining process with the introduction of differential scale parameters. At the end of this process, the refiner has converted each scale-rotation candidate to a refined 4D vector, including rotation, scale, and two differential scale parameters.
At this stage, the detector can pick a 4D vector or set of 4D vector and proceed to calculate the final remaining parameter, translation. Alternatively, the detector can collect additional evidence about the merits of each 4D vector.
One way to collect additional evidence about each 4D vector is to re-compute the detection value of each orientation vector candidate ( 1030 ). For example, the detector may quantize the correlation value associated with each 4D vector as described above for the rotation-scale vector peaks (see item 988 , FIG. 14 and accompanying text). Another way to collect additional evidence is to repeat the coincidence matching process for the 4D vectors. For this coincidence matching process, the detector computes spatial domain vectors for each candidate ( 1032 ), determines the distance metric between candidates from different blocks, and then groups candidates from different blocks based on the distance metrics ( 1034 ). The detector then re-sorts the groups according to their combined detection values ( 1036 ) to produce a set of the top P groupings 1038 for the frame.
FIG. 16 is a flow diagram illustrating a method for aggregating evidence of the orientation signal from multiple frames. In applications with multiple frames, the detector collects the same information for orientation vectors of the selected blocks in each frame (namely, the top P groupings of orientation vector candidates, e.g., 1050 , 1052 and 1054 ). The detector then repeats coincidence matching between orientation vectors of different frames ( 1056 ). In particular, in this inter-frame mode, the detector quantizes the distance metrics computed between orientation vectors from blocks in different frames ( 1058 ). It then finds inter-frame groupings of orientation vectors (super-groups) using the same approach described above ( 1060 ), except that the orientation vectors are derived from blocks in different frames. After organizing orientation vectors into super-groups, the detector computes a combined detection value for each super-group ( 1062 ) and sorts the super-groups by this detection value ( 1064 ). The detector then evaluates whether to proceed to the next stage ( 1066 ), or repeat the above process of computing orientation vector candidates from another frame ( 1068 ).
If the detection values of one or more super-groups exceed a threshold, then the detector proceeds to the next stage. If not, the detector gathers evidence of the orientation signal from another frame and returns to the inter-frame coincidence matching process. Ultimately, when the detector finds sufficient evidence to proceed to the next stage, it selects the super-group with the highest combined detection value ( 1070 ), and sorts the blocks based on their corresponding detection values ( 1072 ) to produce a ranked set of blocks for the next stage ( 1074 ).
4.3 Estimating Translation Parameters
FIG. 17 is a flow diagram illustrating a method for estimating translation parameters of the orientation signal, using information gathered from the previous stages.
In this stage, the detector estimates translation parameters. These parameters indicate the starting point of a watermarked block in the spatial domain. The translation parameters, along with rotation, scale and differential scale, form a complete 6D orientation vector. The 6D vector enables the reader to extract luminance sample data in approximately the same orientation as in the original watermarked image.
One approach is to use generalized match filtering to find the translation parameters that provide the best correlation. Another approach is to continue to collect evidence about the orientation vector candidates, and provide a more comprehensive ranking of the orientation vectors based on all of the evidence gathered thus far. The following paragraphs describe an example of this type of an approach.
To extract translation parameters, the detector proceeds as follows. In the multi-frame case, the detector selects the frame that produced 4D orientation vectors with the highest detection values ( 1080 ). It then processes the blocks 1082 in that frame in the order of their detection value. For each block ( 1084 ), it applies the 4D vector to the luminance data to generate rectified block data ( 1086 ). The detector then performs dual axis filtering ( 1088 ) and the window function ( 1090 ) on the data. Next, it performs an FFT ( 1092 ) on the image data to generate an array of Fourier data. To make correlation operations more efficient, the detector buffers the fourier values at the orientation points ( 1094 ).
The detector applies a generalized match filter 1096 to correlate a phase specification of the orientation signal ( 1098 ) with the transformed block data. The result of this process is a 2D array of correlation values. The peaks in this array represent the translation parameters with the highest correlation. The detector selects the top peaks and then applies a median filter to determine the center of each of these peaks. The center of the peak has a corresponding correlation value and sub-pixel translation value. This process is one example of getting translation parameters by correlating the Fourier phase specification of the orientation signal and the image data. Other methods of phase locking the image data with a synchronization signal like the orientation signal may also be employed.
Depending on the implementation, the detector may have to resolve additional ambiguities, such as rotation angle and flip ambiguity. The degree of ambiguity in the rotation angle depends on the nature of the orientation signal. If the orientation signal is octally symmetric (symmetric about horizontal, vertical and diagonal axes in the spatial frequency domain), then the detector has to check each quadrant (0-90, 90-180, 180-270, and 270-360 degrees) to find out which one the rotation angle resides in. Similarly, if the orientation signal is quad symmetric, then the detector has to check two cases, 0-180 and 180-270.
The flip ambiguity may exist in some applications where the watermarked image can be flipped. To check for rotation and flip ambiguities, the detector loops through each possible case, and performs the correlation operation for each one ( 1100 ).
At the conclusion of the correlation process, the detector has produced a set of the top translation parameters with associated correlation values for each block. To gather additional evidence, the detector groups similar translation parameters from different blocks ( 1102 ), calculates a group detection value for each set of translation parameters 1104 , and then ranks the top translation groups based on their corresponding group detection values 1106 .
4.4 Refining Translation Parameters
Having gathered translation parameter estimates, the detector proceeds to refine these estimates. FIG. 18 is a flow diagram illustrating a process for refining orientation parameters. At this stage, the detector process has gathered a set of the top translation parameter candidates 1120 for a given frame 1122 . The translation parameters provide an estimate of a reference point that locates the watermark, including both the orientation and message components, in the image frame. In the implementation depicted here, the translation parameters are represented as horizontal and vertical offsets from a reference point in the image block from which they were computed.
Recall that the detector has grouped translation parameters from different blocks based on their geometric proximity to each other. Each pair of translation parameters in a group is associated with a block and a 4D vector (rotation, scale, and 2 differential scale parameters). As shown in FIG. 18 , the detector can now proceed to loop through each group ( 1124 ), and through the blocks within each group ( 1126 ), to refine the orientation parameters associated with each member of the groups.
Alternatively, a simpler version of the detector may evaluate only the group with the highest detection value, or only selected blocks within that group.
Regardless of the number of candidates to be evaluated, the process of refining a given orientation vector candidate may be implemented in a similar fashion. In the refining process, the detector uses a candidate orientation vector to define a mesh of sample blocks for further analysis ( 1128 ). In one implementation, for example, the detector forms a mesh of 32 by 32 sample blocks centered around a seed block whose upper right corner is located at the vertical and horizontal offset specified by the candidate translation parameters. The detector reads samples from each block using the orientation vector to extract luminance samples that approximate the original orientation of the host image at encoding time.
The detector steps through each block of samples ( 1130 ). For each block, it sets the orientation vector ( 1132 ), and then uses the orientation vector to check the validity of the watermark signal in the sample block. It assesses the validity of the watermark signal by calculating a figure of merit for the block ( 1134 ). To further refine the orientation parameters associated with each sample block, the detector adjusts selected parameters (e.g., vertical and horizontal translation) and re-calculates the figure of merit. As depicted in the inner loop in FIG. 18 (block 1136 to 1132 ), the detector repeatedly adjusts the orientation vector and calculates the figure of merit in an attempt to find a refined orientation that yields a higher figure of merit.
The loop ( 1136 ) may be implemented by stepping through a predetermined sequence of adjustments to parameters of the orientation vectors (e.g., adding or subtracting small increments from the horizontal and vertical translation parameters). In this approach, the detector exits the loop after stepping through the sequence of adjustments. Upon exiting, the detector retains the orientation vector with the highest figure of merit.
There are a number of ways to calculate this figure of merit. One figure of merit is the degree of correlation between a known watermark signal attribute and a corresponding attribute in the signal suspected of having a watermark. Another figure of merit is the strength of the watermark signal (or one of its components) in the suspect signal. For example, a figure of merit may be based on a measure of the watermark message signal strength and/or orientation pattern signal strength in the signal, or in a part of the signal from which the detector extracts the orientation parameters. The detector may computes a figure of merit based the strength of the watermark signal in a sample block. It may also compute a figure of merit based on the percentage agreement between the known bits of the message and the message bits extracted from the sample block.
When the figure of merit is computed based on a portion of the suspect signal, the detector and reader can use the figure of merit to assess the accuracy of the watermark signal detected and read from that portion of the signal. This approach enables the detector to assess the merits of orientation parameters and to rank them based on their figure of merit. In addition, the reader can weight estimates of watermark message values based on the figure of merit to recover a message more reliably.
The process of calculating a figure of merit depends on attributes the watermark signal and how the embedder inserted it into the host signal. Consider an example where the watermark signal is added to the host signal. To calculate a figure of merit based on the strength of the orientation signal, the detector checks the value of each sample relative to its neighbors, and compares the result with the corresponding sample in a spatial domain version of the orientation signal. When a sample's value is greater than its neighbors, then one would expect that the corresponding orientation signal sample to be positive. Conversely, when the sample's value is less than its neighbors, then one would expect that the corresponding orientation sample to be negative. By comparing a sample's polarity relative to its neighbors with the corresponding orientation sample's polarity, the detector can assess the strength of the orientation signal in the sample block. In one implementation, the detector makes this polarity comparison twice for each sample in an N by N block (e.g., N=32, 64, etc): once comparing each sample with its horizontally adjacent neighbors and then again comparing each sample with its vertically adjacent neighbors. The detector performs this analysis on samples in the mesh block after re-orienting the data to approximate the original orientation of the host image at encoding time. The result of this process is a number reflecting the portion of the total polarity comparisons that yield a match.
To calculate a figure of merit based on known signature bits in a message, the detector invokes the reader on the sample block, and provides the orientation vector to enable the reader to extract coded message bits from the sample block. The detector compares the extracted message bits with the known bits to determine the extent to which they match. The result of this process is a percentage agreement number reflecting the portion of the extracted message bits that match the known bits. Together the test for the orientation signal and the message signal provide a figure of merit for the block.
As depicted in the loop from blocks 1138 to 1130 , the detector may repeat the process of refining the orientation vector for each sample block around the seed block. In this case, the detector exits the loop ( 1138 ) after analyzing each of the sample blocks in the mesh defined previously ( 1128 ). In addition, the detector may repeat the analysis in the loop through all blocks in a given group ( 1140 ), and in the loop through each group ( 1142 ).
After completing the analysis of the orientation vector candidates, the detector proceeds to compute a combined detection value for the various candidates by compiling the results of the figure of merit calculations. It then proceeds to invoke the reader on the orientation vector candidates in the order of their detection values.
4.5 Reading the Watermark
FIG. 19 is a flow diagram illustrating a process for reading the watermark message. Given an orientation vector and the corresponding image data, the reader extracts the raw bits of a message from the image. The reader may accumulate evidence of the raw bit values from several different blocks. For example, in the process depicted in FIG. 19 , the reader uses refined orientation vectors for each block, and accumulates evidence of the raw bit values extracted from the blocks associated with the refined orientation vectors.
The reading process begins with a set of promising orientation vector candidates 1150 gathered from the detector. In each group of orientation vector candidates, there is a set of orientation vectors, each corresponding to a block in a given frame. The detector invokes the reader for one or more orientation vector groups whose detection values exceed a predetermined threshold. For each such group, the detector loops over the blocks in the group ( 1152 ), and invokes the reader to extract evidence of the raw message bit values.
Recall that previous stages in the detector have refined orientation vectors to be used for the blocks of a group. When it invokes the reader, the detector provides the orientation vector as well as the image block data ( 1154 ). The reader scans samples starting from a location in a block specified by the translation parameters and using the other orientation parameters to approximate the original orientation of the image data ( 1156 ).
As described above, the embedder maps chips of the raw message bits to each of the luminance samples in the original host image. Each sample, therefore, may provide an estimate of a chip's value. The reader reconstructs the value of the chip by first predicting the watermark signal in the sample from the value of the sample relative to its neighbors as described above ( 1158 ). If the deduced value appears valid, then the reader extracts the chip's value using the known value of the pseudo-random carrier signal for that sample and performing the inverse of the modulation function originally used to compute the watermark information signal ( 1160 ). In particular, the reader performs an exclusive OR operation on the deduced value and the known carrier signal bit to get an estimate of the raw bit value. This estimate serves as an estimate for the raw bit value. The reader accumulates these estimates for each raw bit value ( 1162 ).
As noted above, the reader computes an estimate of the watermark signal by predicting the original, un-watermarked signal and deriving an estimate of the watermark signal based on the predicted signal and the watermarked signal. It then computes an estimate of a raw bit value based on the value of the carrier signal, the assignment map that maps a raw bit to the host image, and the relationship among the carrier signal value, the raw bit value, and the watermark signal value. In short, the reader reverses the embedding functions that modulate the message with the carrier and apply the modulated carrier to the host signal. Using the predicted value of the original signal and an estimate of the watermark signal, the reader reverses the embedding functions to estimate a value of the raw bit.
The reader loops over the candidate orientation vectors and associated blocks, accumulating estimates for each raw bit value ( 1164 ). When the loop is complete, the reader calculates a final estimate value for each raw bit from the estimates compiled for it. It then performs the inverse of the error correction coding operation on the final raw bit values ( 1166 ). Next, it performs a CRC to determine whether the read is valid. If no errors are detected, the read operation is complete and the reader returns the message ( 1168 ).
However, if the read is invalid, then the detector may either attempt to refine the orientation vector data further, or start the detection process with a new frame. Preferably, the detector should proceed to refine the orientation vector data when the combined detection value of the top candidates indicates that the current data is likely to contain a strong watermark signal. In the process depicted in FIG. 19 , for example, the detector selects a processing path based on the combined detection value ( 1170 ). The combined detection value may be calculated in a variety of ways. One approach is to compute a combined detection value based on the geometric coincidence of the top orientation vector candidates and a compilation of their figures of merit. The figure of merit may be computed as detailed earlier.
For cases where the read is invalid, the processing paths for the process depicted in FIG. 19 include: 1) refine the top orientation vectors in the spatial domain ( 1172 ); 2) invoke the translation estimator on the frame with the next best orientation vector candidates ( 1174 ); and 3) re-start the detection process on a new frame (assuming an implementation where more than one frame is available) ( 1176 ). These paths are ranked in order from the highest detection value to the lowest. In the first case, the orientation vectors are the most promising. Thus, the detector re-invokes the reader on the same candidates after refining them in the spatial domain ( 1178 ). In the second case, the orientation vectors are less promising, yet the detection value indicates that it is still worthwhile to return to the translation estimation stage and continue from that point. Finally, in the final case, the detection value indicates that the watermark signal is not strong enough to warrant further refinement. In this case, the detector starts over with the next new frame of image data.
In each of the above cases, the detector continues to process the image data until it either makes a valid read, or has failed to make a valid read after repeated passes through the available image data.
5.0 Operating Environment for Computer Implementations
FIG. 20 illustrates an example of a computer system that serves as an operating environment for software implementations of the watermarking systems described above. The embedder and detector implementations are implemented in C/C++ and are portable to many different computer systems. FIG. 20 generally depicts one such system.
The computer system shown in FIG. 20 includes a computer 1220 , including a processing unit 1221 , a system memory 1222 , and a system bus 1223 that interconnects various system components including the system memory to the processing unit 1221 .
The system bus may comprise any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using a bus architecture such as PCI, VESA, Microchannel (MCA), ISA and EISA, to name a few.
The system memory includes read only memory (ROM) 1224 and random access memory (RAM) 1225 . A basic input/output system 1226 (BIOS), containing the basic routines that help to transfer information between elements within the computer 1220 , such as during start-up, is stored in ROM 1224 .
The computer 1220 further includes a hard disk drive 1227 , a magnetic disk drive 1228 , e.g., to read from or write to a removable disk 1229 , and an optical disk drive 1230 , e.g., for reading a CD-ROM or DVD disk 1231 or to read from or write to other optical media. The hard disk drive 1227 , magnetic disk drive 1228 , and optical disk drive 1230 are connected to the system bus 1223 by a hard disk drive interface 1232 , a magnetic disk drive interface 1233 , and an optical drive interface 1234 , respectively. The drives and their associated computer-readable media provide nonvolatile storage of data, data structures, computer-executable instructions (program code such as dynamic link libraries, and executable files), etc. for the computer 1220 .
Although the description of computer-readable media above refers to a hard disk, a removable magnetic disk and an optical disk, it can also include other types of media that are readable by a computer, such as magnetic cassettes, flash memory cards, digital video disks, and the like.
A number of program modules may be stored in the drives and RAM 1225 , including an operating system 1235 , one or more application programs 1236 , other program modules 1237 , and program data 1238 .
A user may enter commands and information into the computer 1220 through a keyboard 1240 and pointing device, such as a mouse 1242 . Other input devices may include a microphone, joystick, game pad, satellite dish, digital camera, scanner, or the like. A digital camera or scanner 43 may be used to capture the target image for the detection process described above. The camera and scanner are each connected to the computer via a standard interface 44 . Currently, there are digital cameras designed to interface with a Universal Serial Bus (USB), Peripheral Component Interconnect (PCI), and parallel port interface. Two emerging standard peripheral interfaces for cameras include USB2 and 1394 (also known as firewire and iLink).
Other input devices may be connected to the processing unit 1221 through a serial port interface 1246 or other port interfaces (e.g., a parallel port, game port or a universal serial bus (USB)) that are coupled to the system bus.
A monitor 1247 or other type of display device is also connected to the system bus 1223 via an interface, such as a video adapter 1248 . In addition to the monitor, computers typically include other peripheral output devices (not shown), such as speakers and printers.
The computer 1220 operates in a networked environment using logical connections to one or more remote computers, such as a remote computer 1249 . The remote computer 1249 may be a server, a router, a peer device or other common network node, and typically includes many or all of the elements described relative to the computer 1220 , although only a memory storage device 1250 has been illustrated in FIG. 20 . The logical connections depicted in FIG. 20 include a local area network (LAN) 1251 and a wide area network (WAN) 1252 . Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet.
When used in a LAN networking environment, the computer 1220 is connected to the local network 1251 through a network interface or adapter 1253 . When used in a WAN networking environment, the computer 1220 typically includes a modem 1254 or other means for establishing communications over the wide area network 1252 , such as the Internet. The modem 1254 , which may be internal or external, is connected to the system bus 1223 via the serial port interface 1246 .
In a networked environment, program modules depicted relative to the computer 1220 , or portions of them, may be stored in the remote memory storage device. The processes detailed above can be implemented in a distributed fashion, and as parallel processes. It will be appreciated that the network connections shown are exemplary and that other means of establishing a communications link between the computers may be used.
While the computer architecture depicted in FIG. 20 is similar to typical personal computer architectures, aspects of the invention may be implemented in other computer architectures, such as hand-held computing devices like Personal Digital Assistants, audio and/video players, network appliances, telephones, etc.
6.0 Concluding Remarks
Having described and illustrated the principles of the technology with reference to specific implementations, it will be recognized that the technology can be implemented in many other, different, forms. The techniques for embedding and detecting a watermark may be applied to various types of watermarks, including those encoded using linear or non-linear functions to apply a watermark message to a host signal. As one example, embedding methods, such as methods for error correction coding, methods for mapping watermark messages to the host signal, and methods for redundantly encoding watermark messages apply whether the watermarking functions are linear or non-linear. In addition, the techniques for determining and refining a watermark's orientation apply to linear and non-linear watermark methods. For example, the methods described above for detecting orientation of a watermark signal in a potentially transformed version of the watermarked signal apply to watermark systems that use different methods for embedding and reading messages, including, but not limited to, techniques that modulate spatial or temporal domain intensity values, that modulate transform coefficients, that employ dither modulation or quantization index modulation.
Some of the detector methods described above invoke a watermark message reader to assess the merits of a given orientation of a watermark signal in a potentially transformed version of the watermarked signal. In particular, some of these techniques assess the merits of an orientation by invoking a reader to determine the extent to which known message bits agree with those read from the watermarked signal using the orientation. These techniques are not specific to the type of message encoding or reading as noted in the previous paragraph. The merits of a given estimate of a watermark signal's orientation may be assessed by selecting an orientation parameter that increases correlation between the watermark signal (or known watermark signal attributes) and the watermarked signal, or that improves recovery of known watermark message bits from the watermark signal.
Some watermark readers extract a message from a watermarked signal by correlating known attributes of a message symbol with the watermarked signal. For example, one symbol might be associated with a first pseudorandom noise pattern, while another symbol is associated with another pseudorandom noise pattern. If the reader determines that a strong correlation between the known attribute and the watermark signal exists, then it is likely that the watermarked signal contains the message symbol.
Other watermark readers analyze the watermarked signal to identify attributes that are associated with a message symbol. Generally speaking, these watermark readers are using a form of correlation, but in a different form. If the reader identifies evidence of watermark signal attributes associated with a message symbol, it notes that the associated message symbol has likely been encoded. For example, readers that employ quantization index modulation analyze the watermarked signal by applying quantizers to the signal to determine which quantizer was most likely used in the embedder to encode a message. Since message symbols are associated with quantizers, the reader extracts a message by estimating the quantizer used to encode the message. In these schemes, the signal attribute associated with a message symbol is the type of quantization applied to the signal. Regardless of the signal attributes used to encode and read a watermark message, the methods described above for determining watermark orientation and refining orientation parameters still apply.
To provide a comprehensive disclosure without unduly lengthening the specification, applicants incorporate by reference the patents and patent applications referenced above. Additional information is provided in a section entitled “Smart Images” Using Digimarc's Watermarking Technology in U.S. Pat. No. 6,614,914 which is also incorporated by reference. This section describes additional embodiments and applications of watermark embedding and detecting technology. For additional information about a detector optimization that looks for a watermark in portions of a signal that are more likely to contain a recoverable watermark signal, see U.S. patent application Ser. No. 09/302,663, filed Apr. 30, 1999, entitled Watermark Detection Utilizing Regions with Higher Probability of Success, by Ammon Gustafson, Geoffrey Rhoads, Adnan Alattar, Ravi Sharma and Clay Davidson (Now U.S. Pat. No. 6,442,284).
The particular combinations of elements and features in the above-detailed embodiments are exemplary only; the interchanging and substitution of these teachings with other teachings in this and the incorporated-by-reference patents/applications are also contemplated. | The present disclosure relates generally to encoding and decoding signals from media signals. One claim recites an apparatus comprising: electronic memory for storing blocks of a media signal; an electronic processor programmed for: determining a detection metric for the blocks, the detection metric comprising a measure of coincidence of detection parameters of different blocks; and performing detection operations based on the measure of coincidence of the detection parameters. Of course, other claims and combinations are provided as well. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of co-pending U.S. application Ser. No. 09/122,285 filed Jul. 24, 1998 and entitled “Controlled-Shaped Solder Reservoirs for Increasing the Volume of Solder Bumps, and Structures Formed Thereby,” which is a continuation-in-part of U.S. application Ser. No. 08/977,258, now U.S. Pat. No. 5,892,179, filed Nov. 24, 1997, which is a file wrapper continuation of U.S. patent application Ser. No. 08/416,619, filed Apr. 4, 1995, now abandonded. In addition, this application claims benefit of U.S. Provisional Application No. 60/053,761, now abandoned entitled “Controlled-Shaped Solder Reservoirs for Increasing the Volume of Solder Structures,” filed Jul. 25, 1997.
FIELD OF THE INVENTION
This invention relates to the field of microelectronic devices, and more particularly to solder bumps for microelectronic devices.
BACKGROUND OF THE INVENTION
High performance microelectronic devices often use solder balls or solder bumps for electrical and mechanical interconnection to other microelectronic devices. For example, a very large scale integration (VLSI) chip may be electrically connected to a circuit board or other next level packaging substrate using solder balls or solder bumps. This connection technology is also referred to as “Controlled Collapse Chip Connection—C4” or “flip-chip” technology, and will be referred to herein as “solder bumps”.
A significant advance in this technology is disclosed in U. S. Pat. No. 5,162,257 to Yung entitled “Solder Bump Fabrication Method” and assigned to the assignee of the present invention. In this patent, an under bump metallurgy is formed on the microelectronic substrate including contact pads, and solder bumps are formed on the under bump metallurgy opposite the contact pads. The under bump metallurgy between the solder bumps and the contact pads is converted to an intermetallic which is resistant to etchants used to etch the under bump metallurgy between solder bumps. Accordingly, the base of the solder bumps is preserved.
In many circumstances, it may be desired to provide a solder bump on the substrate at a location remote from the contact pad and also form an electrical connection between the contact pad and the solder bump. For example, a microelectronic substrate may be initially designed for wire bonding with the contact pads arranged around the outer edge of the substrate. At a later time it may be desired to use the microelectronic substrate in an application requiring solder bumps to be placed in the interior of the substrate. In order to achieve the placement of a solder bump on the interior of the substrate away from the respective contact pad, an interconnection or redistribution routing conductor may be necessary.
U.S. Pat. No. 5,327,013 to Moore et al. entitled “Solder Bumping of Integrated Circuit Die” discloses a method for forming a redistribution routing conductor and solder bump on an integrated circuit die. This method includes forming a terminal of an electrically conductive, solder-wettable composite material. The terminal includes a bond pad overlying the passivation layer remote from a metal contact and a runner that extends from the pad to the metal contact. A body of solder is reflowed onto the bond pad to form a bump bonded to the pad and electrically coupled through the runner.
In this method, however, the solder bump is formed by pressing a microsphere of a solder alloy onto the bond pad. In addition, the spread of solder along the runner during reflow is limited. In the illustrated embodiment, a solder stop formed of a polymeric solder resist material is applied to the runner to confine the solder to the bond pad.
In many circumstances, it is desirable to form relatively tall solder bumps. For example, taller solder bumps provide a larger opening between a microelectronic chip and substrate in a flip-chip module, which facilitates improved cleaning and underfill. In addition, it is generally excepted that taller solder bumps are more reliable because the straining per unit length is proportionally reduced with the increase in bump height.
A known technique for increasing solder bump height is to increase the volume solder with the same diameter solder pad. However, this technique typically requires more space on the substrate for plating or depositing the additional solder, and/or requires additional process steps. As a consequence, the benefit of increasing the bump height is often offset, at least in part, by the increase in surface area required for a single bump, and or, the additional cost associated with providing additional solder. Other methods of decreasing the strain per unit length in the solder includes casting pillars, posts, or beams of high melting point solder and attaching these to the semiconductor using lower temperature solders.
Notwithstanding the above mentioned references, there continues to exist a need in the art for solder bump structures that are relatively tall, do not require additional surface area, and can be fabricated efficiently and at a reduced cost.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved solder bump structure.
It is another object of the present invention to provide solder bump structure with a solder redistribution reservoir for increasing the volume, and thus the height, of the solder bump.
It is another object of the present invention to provide an improved vacuum in a sealed chamber including a microelectronic device.
These and other objects are provided, according to the present invention, by a controlled-shaped solder reservoir which provides additional solder to a bump in the reflow step for increasing the volume of solder forming the solder bump. The controlled shaped reservoirs can be shaped and sized to provide predetermined amounts of solder to the solder bump. Thus, the height of the resulting solder bump can be predetermined, not to mention that the height is greater than that of similar solder bumps without solder redistribution reservoirs because of the additional solder volume added by the reservoirs. To accommodate the stringent space requirement in many microelectronic chip designs, the solder reservoir can be shaped to take a minimum amount of space. Consequently, the solder bumps may have increased height without adding to the space requirements of the solder bump, or without increasing the cost.
Other advantages of the solder structures formed in accordance with the present invention include an increase opening or gap in a flip-chip structure because of the taller solder bumps. This allows for more efficient cleaning of flux and other residues, and more efficient underfilling. The taller solder bumps can also be utilized in conjunction with electrical contact bumps that do not have solder reservoirs so that the contact bumps are elongated by the relatively larger bumps formed with the assistance of the additional solder from the reservoirs. Consequently, the contact bumps are more reliable because the strain is distributed over a greater length (i.e., height) because of the relatively larger volume bumps. Yet another advantage is that the relatively taller solder bumps can be utilized to increase the volume, and thus reduce the pressure, of a sealed chamber in a MEMS vacuum package. This enables a lower pressure vacuum environment to the generated without the equipment typically needed to generate such low pressures vacuums. Further, a single masking step can be used to define both the solder bump structure, including the solder redistribution reservoir, and the under bump metallurgy layer.
In accordance with one embodiment of the present invention, a solder structure on a microelectronic substrate comprises a solder reservoir portion and a solder bump portion, and wherein the solder reservoir portion is non-linear in shape. The solder reservoir portion may wrap around the solder bump portion in order to take up less space. In addition, the solder structure may comprise a plurality of solder reservoir portions extending from the solder bump portion. Preferably, the radially extending solder reservoirs are of substantially equal length, though the reservoirs can be of varying lengths.
Further, the solder reservoir portion may be shaped to create a pressure gradient along the length of the solder reservoir portion during a solder reflow process. Accordingly, the rate of solder flow can be controlled, which may be highly desirable in particular circumstances. The pressure gradient may increase the flow rate of solder to the solder bump portion, or the pressure gradient may decrease the flow rate of solder to the solder bump portion.
In order to reduce the area taken by the solder bump structure, the solder reservoir portion may include a notch for facilitating the removal of the residual solder of the solder reservoir portion subsequent to the solder reflow process. The removal of the residual solder may be further facilitated by the use of high-lead solders which may facilitate the incomplete conversion of copper in the under bump metallurgy. Thus, the remaining copper may be dissolved in the subsequent etch step, thereby allowing the residual solder of the reservoir to break off at the weak point created by the notch, and float away in the etchant.
In accordance with another aspect of the present invention, a solder structure on a microelectronic substrate comprises a solder reservoir portion and a solder bump portion, and wherein the solder reservoir portion has a width which is non-uniform in at least a portion of the reservoir portion. Accordingly, a pressure gradient can be achieved within the solder reservoir to either increase or decrease the flow rate of the solder to the bump structure during the solder flow process. As mentioned above, controlling the flow rate of the solder in the solder flow process may be desirable in certain applications.
In accordance with yet another aspect of the present invention, a microelectromechanical system (MEMS) module comprises a substrate and a lid in spaced apart relationship, a solder ring which bonds the lid to the substrate to define a sealed chamber therebetween, wherein the solder ring includes at least one solder reservoir associated therewith. In addition, the device includes a MEMS device formed in the chamber.
A second solder ring that is concentrically aligned with the first solder ring may be included, wherein the second solder ring also includes at least one solder reservoir associated therewith. The MEMS module may further comprise elongated electrical contacts within the chamber, wherein the elongated electrical contacts electrically connect the lid to the substrate. Preferably, the chamber is a controlled environment maintained at a vacuum.
In accordance with another aspect of the present invention, a flip-chip structure comprises a substrate and a chip in spaced apart relationship, an elongated contact bump which electrically connects the lid to the substrate, and a plurality of mechanical bumps bonding the chip to the substrate, wherein the mechanical bumps include solder reservoirs associated therewith. The solder reservoirs associated with the mechanical bumps may be non-linear, and may have a non-uniform width portion, as discussed above.
A method in accordance with the present invention for forming a solder bump structure on a microelectronic substrate comprises the steps of forming an under bump metallurgy layer on the microelectronic substrate, and forming a solder structure on the under bump metallurgy layer opposite the microelectronic substrate, wherein the solder structure includes a non-linear solder reservoir portion and a solder bump portion. The step of forming the solder structure may include the step of forming a solder structure including a plurality of solder reservoirs. In addition, the step of forming the solder structure may include the step of forming a solder bump portion and a reservoir which at least partially wraps around the solder bump portion. Yet further, the step of forming the solder structure may include the step of forming a solder structure including a solder reservoir shaped to create a pressure gradient along a length of the solder reservoir.
In accordance with another aspect of the present invention, a method of forming a solder bump structure on a microelectronic substrate comprises the steps of forming an under bump metallurgy layer on the microelectronic substrate, and forming a solder structure on the under bump metallurgy layer opposite the microelectronic substrate, wherein the solder structure included a solder bump portion and a plurality of solder reservoir portions extending therefrom.
In accordance with yet another aspect of the present invention, a method for forming a flip-chip module comprises the steps of forming a contact solder bump structure on a microelectronic substrate, forming a plurality of mechanical solder bump structures on the microelectronic substrate, wherein said mechanical solder bump structures have respective solder reservoirs associated therewith. Since the flow of molten solder from the reservoir to the bump takes time, the present invention provides a means for sequencing aspects of the soldering operation. Further, the method includes the steps of mating the microelectronic substrate to a second substrate, and reflowing the solder of the contact solder bumps and the mechanical solder bumps to bond the microelectronic substrate to the second substrate, wherein the contact solder bump becomes elongated due to the relatively larger mechanical solder bumps that will form after a brief delay.
In accordance with another aspect of the present invention, a method of forming a flip-chip module comprises the steps of forming a solder ring on a microelectronic substrate, wherein said solder ring includes at least one solder reservoir associated therewith, mating the microelectronic substrate to a second substrate in a vacuum environment to define a chamber therebetween, and reflowing the solder of the solder ring to seal the microelectronic substrate to the second substrate and to increase the volume of the chamber. Thus, because of the increased volume of the sealed chamber, the chamber is at a relatively lower pressure than the vacuum environment. The method may further include the step of forming a second solder ring substantially concentrically aligned with the solder ring, wherein the second solder ring includes at least one solder reservoir associated therewith.
Other features and advantages of the present invention will become apparent to one that is skilled in the art upon examination of the following drawings and detailed description. It is intended that all such additional features and advantages be included herein within the scope of the present invention, as defined in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-5 are cross sectional side views of a microelectronic substrate at various stages during the manufacture of a redistribution routing conductor according to the present invention.
FIGS. 6-10 are top views of a microelectronic substrate at various stages during the manufacture of a redistribution routing conductor corresponding respectively to FIGS. 1-5.
FIGS. 11-16 are top plan views of various embodiments of controlled shaped solder reservoirs in accordance with the present invention.
FIG. 17 is a graph illustrating the relationship of the reservoir width and the internal pressure of the solder.
FIG. 18 is a cross sectional view of a flip-chip structure incorporating the solder reservoirs of the present invention.
FIG. 19 is a top plan of a substrate including mechanical contact bumps that include solder reservoirs in accordance with the present invention and electrical contact bumps.
FIGS. 20A-20C are cross sectional views of a microelectronic substrate at various stages during the manufacture of a control pressure chamber in accordance with the present invention.
FIG. 21 is a bottom plan of the top substrate in FIGS. 20 A- 20 C.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of layers and regions are exaggerated for clarity. Like numbers refer to like elements throughout.
I. Redistribution Routing Conductors
A microelectronic structure 11 includes a redistribution routing conductor and a raised solder bump, as shown from the side in FIG. 5 and as shown from the top in corresponding FIG. 10 . The microelectronic structure includes a contact pad 14 and passivation layer 12 on a substrate 15 . The redistribution routing conductor 17 and solder bump 21 each include respective portions of under bump metallurgy layer 16 A-B and solder layer 22 A-B.
The redistribution routing conductor 17 includes a relatively elongate solder portion 22 B (also referred to herein as a solder reservoir) on a respective elongate under bump metallurgy portion 16 B. The solder bump 21 includes an enlarged width solder portion 22 A on a respective enlarged width under bump metallurgy portion 16 A. Preferably the elongate solder portion 22 B is relatively thin while the enlarged width solder portion 22 A is raised, as shown in FIG. 5 .
Accordingly, the solder bump 21 can be located at a point on the substrate relatively distant from the contact pad 14 with the redistribution routing conductor 17 providing an electrical connection therebetween. This arrangement provides the advantage that a substrate having a layout with a contact pad 14 at one predetermined location can have an associated solder bump at a second location. This can be particularly useful, for example, when a substrate has a layout with contact pads arranged for wire bonding, and it is desired to use the substrate in a flip-chip application. This solder bump and redistribution routing conductor can be fabricated simultaneously, as described below with regard to FIGS. 1-10.
While the redistribution routing conductor 17 can be straight as shown, it may also include bends and curves. Furthermore, the solder bump 21 may be circular as shown or it can have other shapes such as rectangular.
The solder bump 21 and the redistribution routing conductor 17 are preferably formed simultaneously. FIGS. 1-5 are cross-sectional side views of microelectronic structures at various stages of fabrication, while FIGS. 6-10 are corresponding top views of the same microelectronic structures. The microelectronic structure 11 initially includes a passivation layer 12 and an exposed contact pad 14 on a substrate 15 , as shown in FIGS. 1 and 6.
The substrate 15 can include a layer of a semiconducting material such as silicon, gallium arsenide, silicon carbide, diamond, or other substrate materials known to those having skill in the art. This layer of semiconducting material can in turn include one or more electronic devices such as transistors, resistors, capacitors, and/or inductors. The contact pad 14 may comprise aluminum, copper, titanium, an intermetallic including combinations of the aforementioned metals such as AlCu and AlTi 3 , or other materials known to those having skill in the art. This contact is preferably connected to an electronic device in the substrate.
The passivation layer 12 can include polyimide, silicon dioxide, silicon nitride, or other passivation materials known to those having skill in the art. As shown, the passivation layer 12 may cover top edge portions of the contact pad 14 opposite the substrate 15 , leaving the central portion of the contact pad 14 exposed. As will be understood by those having skill in the art, the term substrate may be defined so as to include the passivation layer 12 and contact pad 14 of FIGS. 1 and 6.
An under bump metallurgy layer 16 is formed on the passivation layer to provide a connection between the solder bump and the contact pad 14 and to provide a plating electrode, as shown in FIGS. 2 and 7. The under bump metallurgy layer 16 also protects the contact pad 14 and passivation layer 12 during subsequent processing steps, and provides a surface to which the solder will adhere. The under bump metallurgy layer preferably includes a chromium layer on the passivation layer 12 and contact pad 14 ; a phased chromium/copper layer on the chromium layer; and a copper layer on the phased layer. This structure adheres to and protects the passivation layer 12 and contact pad 14 , and also provides a base for the plated solder which follows.
The under bump metallurgy layer may also include a titanium barrier layer between the substrate and the chromium layer as disclosed in U. S. Pat. No. 5,767,010 entitled “Solder Bump Fabrication Methods and Structures Including a Titanium Barrier Layer,” and assigned to the assignee of the present invention. This titanium barrier layer protects the passivation layer from etchants used to remove the other components of the under bump metallurgy layer and also prevents the formation of residues on the passivation layer which may lead to shorts between solder bumps and redistribution routing conductors. The titanium layer can be easily removed from the passivation layer without leaving significant residues.
Various under bump metallurgy layers are disclosed, for example, in U.S. Pat. No. 4,950,623 to Dishon entitled “Method of Building Solder Bumps”, U.S. Pat. No. 5,162,257 to Yung entitled “Solder Bump Fabrication Method”, and U.S. Pat. No. 5,767,010 to Mis et al. entitled “Solder Bump Fabrication Methods and Structures Including a Titanium Barrier Layer.” Each of these references is assigned to the assignee of the present invention, and the disclosure of each is hereby incorporated in its entirety herein by reference.
A solder dam 18 can be formed on the under bump metallurgy layer 16 . This solder dam 18 preferably includes a layer of a solder non-wettable material such as titanium or chromium on the under bump metallurgy layer 16 . The solder dam 18 will be used to contain the solder if a reflow step is performed prior to removing the first (exposed) portion of the under bump metallurgy layer 16 not covered by solder, as discussed below. A mask layer 20 is then formed on the solder dam 18 . The mask layer may comprise a photoresist mask or other mask known to those having skill in the art.
The mask layer 20 is patterned to cover the solder dam over the first portion of the under bump metallurgy layer and to uncover areas of the solder dam 18 over a second portion of the under bump metallurgy layer 16 on which the solder bump and redistribution routing conductor will be formed. The uncovered portion of the solder dam is then removed thereby uncovering the second portion of under bump metallurgy layer 16 , as shown in FIGS. 3 and 8. More particularly, the second portion of the under bump metallurgy layer 16 , which is not covered by the solder dam and patterned mask layer, includes an enlarged width portion 16 A and an elongate portion 16 B.
A solder layer 22 is preferably electroplated on the second portion of the under bump metallurgy layer 16 , as shown in FIGS. 4 and 9. The solder can be electroplated by applying an electrical bias to the continuous under bump metallurgy layer 16 and immersing the microelectronic structure in a solution including lead and tin, as will be understood by those having skill in the art. This electroplating process allows solder layers to be formed simultaneously on a plurality of second portions of the under bump metallurgy layer 16 . The solder will not plate on the mask layer 20 . Alternatively, the solder can be applied by screen printing as a paste, by evaporation, by e-beam deposition, by electroless deposition or by other methods known to those having skill in the art. In addition, while lead-ti solder is used for purposes of illustration throughout the specification, other solders such as gold solder, lead-indium solder, or tin solder can be used as will be understood by those having skill in the art.
The solder layer 22 includes an elongate portion 22 B and an enlarged width portion 22 A. After removing the mask layer 20 , the microelectronic structure 11 can be heated causing the solder to flow from the elongate solder portion 22 B to the enlarged width solder portion 22 A thereby forming a raised solder bump at the enlarged width solder portion 22 A. The solder dam 18 prevents the solder from spreading beyond the elongate 16 B and enlarged width 16 A portions of the under bump metallurgy layer 16 , as shown in FIGS. 5 and 10.
The solder will flow when heated above its liquidous temperature (approximately 299° C. for solder having 90% lead and 10% tin), and this process is commonly referred to as solder reflow. During reflow, the surface tension of the solder creates a relatively low internal pressure in the enlarged width solder portion 22 A over the relatively wide geometry provided for the solder bump, and a relatively high internal pressure in the elongate solder portion 22 B over the relatively narrow geometry provided for the redistribution routing conductor.
In order to equalize this internal pressure differential, solder flows from the elongate solder portion 22 B to the enlarged width solder portion 22 A. Accordingly, the solder forms a raised solder bump at the enlarged width solder portion 22 A and a relatively thin layer of solder at the elongate solder portion 22 B over the redistribution routing conductor. When the solder is cooled below its liquidus temperature, it solidifies maintaining its shape including the raised solder bump and the thin layer of solder over the redistribution routing conductor.
It is known in the art of printed circuit board manufacture to apply solder at a uniform level on PCB lands by screen printing, and that the level of solder can be increased locally by enlarging a part of the land. See, Swanson, “PCB Assembly: Assembly Technology in China,” Electronic Packaging & Production, pp. 40, 42, January 1995. To their knowledge, however, Applicants are the first to realize that solder can be electroplated on a microelectronic substrate at a uniform level and then heated to produce a raised solder bump together with a redistribution routing conductor on the substrate.
Furthermore, U.S. Pat. No. 5,327,013 to Moore et al. states that a microsphere of a solder alloy can be pressed onto a pad, and that a stop formed of a polymeric solder resist material can be applied to the runner to confine the solder to the bond pad. While this patent states that the spread of solder along the runner during reflow can be limited by constricting the width of the runner section relative to the bond pad, there is no suggestion that the relative dimensions of the runner section and the bond pad can be used to cause solder to flow from the runner to the bond pad thereby forming a multilevel solder structure. In addition, neither of these references suggest that a solder structure having an elongate portion and an enlarged width portion can be used to mask the under bump metallurgy layer in order to form a redistribution routing conductor together with a raised solder bump using only a single masking step.
The method described herein relies on differences in the surface-tension induced internal pressure of the reflowed (liquid) solder to form a thin layer of solder at the elongate solder portion 22 B and a raised solder bump at the enlarged width solder portion 22 A. The internal pressure P of a liquid drop of solder can be determined according to the formula:
P =2 T/r,
where T is the surface tension of the liquid solder, and r is the radius of the drop.
Where liquid solder is on a flat wettable surface such as the under bump metallurgy layer, the formula becomes:
P =2 T/r′.
In this formula, r′ is the apparent radius of the liquid solder, and the apparent radius is the radius of the of the arc (radius of curvature) defined by the exposed surface of the solder. The apparent radius is dependent on the width of the underlying solder wettable layer such as the second portion of the under bump metallurgy layer which is in contact with the solder. Accordingly, the internal pressure of a reflowed solder structure is inversely proportional to the width of the second portion of the under bump metallurgy in contact with the solder. Stated in other words, a solder portion having on a relatively wide under bump metallurgy portion will have a relatively low internal pressure while a solder portion on an elongate (relative narrow) under bump metallurgy portion will have a relatively high internal pressure. The internal pressures will equalize when the apparent radii of the elongate solder portion 22 B and the enlarged width solder portion 22 A are approximately equal.
Accordingly, when the solder layer 22 with a uniform level illustrated in FIGS. 4 and 9 is heated above its liquidus temperature, solder flows from the elongate solder portion 22 B to the enlarged width solder portion 22 A until each portion has approximately the same apparent radius thereby forming a raised solder bump. If the solder flow step is performed prior to removing the first portion of the under bump metallurgy layer 16 not covered by the solder structure, an intermetallic can be formed between the solder portions 22 A-B and under bump metallurgy portions 16 A-B adjacent the solder wherein the intermetallic is resistant to etchants commonly used to remove the under bump metallurgy. Accordingly, this intermetallic reduces undercutting of the solder during the following step of removing the first portion of the under bump metallurgy not covered by solder, as discussed in U. S. Pat. No. 5,162,257 to Yung entitled “Solder Bump Fabrication Method” and assigned to the assignee of the present invention.
Preferably, the under bump metallurgy layer 16 includes a copper layer adjacent the solder structure and the solder is a lead-tin solder. Accordingly, the step of causing the solder to flow will cause the solder to react with the copper to form an intermetallic region adjacent the solder structure, and this intermetallic will comprise Cu 3 Sn. This intermetallic does not readily react with etchants commonly used to remove under bump metallurgy layers thereby reducing undercutting of the solder structure.
The solder layer 22 is then preferably used as a mask to selectively etch the first portions of the solder dam 18 and under bump metallurgy 16 not covered by solder. A chemical etchant can be used which etches the under bump metallurgy layer 16 preferentially with respect to the solder portions 22 A-B. Accordingly, no additional masking step is required to pattern the under bump metallurgy layer. Stated in other words, the formation of mask layer 20 is the only masking step required to pattern the solder dam 18 (FIGS. 3 and 8 ), selectively expose the second portion of the under bump metallurgy layer 16 during the plating step (FIGS. 3 and 8 ), and remove the first portions of the under bump metallurgy layer not covered by solder after the plating step (FIGS. 5 and 10 ).
Alternately, the first portions of the under bump metallurgy layer 16 not covered by solder portions 22 A and 22 B can be selectively removed prior to causing the solder to flow. In this case, the elongate 22 B and enlarged width 22 A solder portions are respectively supported on only the elongate 16 B and enlarged width 16 A under bump metallurgy portions, and while the liquid solder is wettable to the under bump metallurgy, it is not wettable to the passivation layer 12 . Accordingly, the passivation layer can contain the solder during the solder flow step, and the solder dam 18 can be eliminated.
In another alternative, the solder dam can include a solder non-wettable layer on the under bump metallurgy layer 16 and a solder wettable layer, such as copper, on the solder non-wettable layer opposite the under bump metallurgy layer, as disclosed in U. S. Pat. No. 5,767,010 to Mis et al. entitled “Solder Bump Fabrication Methods and Structures Including a Titanium Barrier Layer”. The solder wettable layer allows solder to be plated on portions of the solder dam as well as the second portion of the under bump metallurgy layer not covered by the solder dam or mask.
Accordingly, the mask layer 20 can uncover portions of the solder dam as well as portions of the under bump metallurgy layer 16 thereby allowing a greater volume of solder to be plated. The mask layer 20 and underlying portions of the solder wettable layer are then removed. When heat is applied to cause the solder to flow, the remaining portion of the solder wettable layer under the solder will be dissolved into the solder exposing the solder to the solder non-wettable layer. Accordingly, the solder will retreat to the second portion of the under bump metallurgy layer which is wettable.
As an example, a first portion of the under bump metallurgy layer 16 is covered by a solder dam 18 and a mask layer 20 . A second portion of the under bump metallurgy layer 16 is uncovered and has an elongate portion 16 B that is 150 micrometers wide and 500 micrometers long, and a circular enlarged width portion 16 A with a 500 micrometers diameter (or width), as shown in FIGS. 3 and 8. A uniform 35 micrometers high solder layer 22 is then electroplated on the second portion of the under bump metallurgy layer 16 including elongate portion 16 A and enlarged width portion 16 B, as shown in FIG. 4 . This solder is 90% lead and 10% tin. After removing the mask layer 20 , the solder is heated above its liquidus temperature (approximately 299° C.) allowing it to flow.
The liquid solder is contained on the second portion 16 A-B of the solder wettable under bump metallurgy layer by the solder dam 18 to which the solder will not wet. Because the solder structure has varying widths, the internal pressure of the solder structure is not consistent when the height is uniform. In particular, the internal pressure of the elongate solder portion 22 B is relatively high (approximately 1.283×10 4 Pa or 1.86 psi) and the internal pressure of the enlarged width solder portion 22 A is relatively low (approximately 3.848×10 3 Pa or 0.558 psi) at the original solder height.
Accordingly, solder flows from the elongate solder portion 22 B to the enlarged width solder portion 22 A until the internal pressures equalize, thereby forming a raised solder bump at the enlarged width solder portion 22 A, as shown in FIGS. 5 and 10. In FIGS. 5 and 10, the solder dam 18 and the first portion of the under bump metallurgy layer 16 not covered by the solder structure have also been removed.
In this example, equilibrium is obtained at an internal pressure of approximately 3.4×10 3 Pa (0.493 psi). At equilibrium, the elongate solder portion 22 B is approximately 10 micrometers high and the enlarged width solder portion 22 A is approximately 130 micrometers high, and both portions have a radius of curvature of approximately 281 micrometers. Accordingly, a two level solder structure can be provided with a single masking step. When cooled, this structure solidifies while maintaining its form. In addition, the elongate solder portion 22 B with a solder height of 10 micrometers is sufficient to mask the respective elongate under bump metallurgy layer portion 16 B when removing the first portion of the under bump metallurgy layer not covered by solder. The enlarged width portion of the solder structure may have a width (or diameter if the enlarged width portion is circular) of at least two times a width of the elongate portion of the solder structure in order to ensure that the solder bump formed by the method described above is sufficiently raised relative to the elongate solder portion to provide an adequate connection to a printed circuit board.
In the drawings and specification, there have been disclosed typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.
II. Controlled-Shaped Solder Reservoirs
As described above, the elongate solder portion 22 B functions as a solder redistribution reservoir for the enlarged with solder portion 22 A. The surface-tension induced pressure differential causes the molten solder in a relatively high pressure elongate solder portion 22 B to flow to the relatively lower pressure enlarged width portion 22 A. The increasing solder volume at the enlarged width portion 22 A forms a raised solder bump. A solder bump so formed generally has a relatively larger height than solder bumps formed without solder redistribution reservoirs when utilizing the same pad diameter and solder plating thickness. Thus, by taking advantage of the surface-tension induced pressure differential between a solder redistribution reservoir and an elongate width portion, such as a solder bump, relatively taller bumps can be advantageously achieved. The following description is of various embodiments of solder structures which take advantage of this pressure differential to produce more efficient and reliable solder structures.
With reference to FIG. 11, a solder structure 30 in accordance with the present invention as illustrated. The solder structure 30 includes a square solder redistribution reservoir 32 , and a channel 34 that connects the solder redistribution reservoir 32 to an enlarged with portion, such as bump 34 . Accordingly, as a solder forming the solder structure is heated to its liquidus state to cause the solder to flow, commonly referred to as solder reflow, the solder flows from the solder redistribution reservoir 32 to the bump 36 via the channel 34 due to the internal pressure differential. The additional solder from the solder redistribution reservoir 32 increases the volume of solder forming the solder bump, thereby forming a relatively taller solder bump. Thus, the space between adjacent bumps in an area array can be utilized to store the solder that flows into the bumps during reflow.
As an example, assume an area array flip chip with 0.125 mm diameter pads on a 0.25 mm pitch, a minimum spacing for features in the plating template of 0.025 mm, and plating solder that is 0.05 mm thick. A solder bump under these circumstances would have a solder volume of 6.4 E-4 mm 3 , and a height of 0.07 mm. However, by providing a solder redistribution reservoir 32 around the solder bump pad, as shown in FIG. 11, that is 0.063 mm wide and 0.25 mm square, the bump volume increases to 1.23 E-3 mm 3 . Accordingly, solder bump height is significantly increased while not affecting the solder bump pitch in the array.
It is noted that the solder structure 30 , and those structures discussed below, is preferably fabricated with the single mask process described above, though it will be recognized by those of ordinary skill in the art that other suitable solid, liquid, vapor, and electromechanical deposition methods may be utilized, as well known in the art. Further, it is noted that while the solder bumps described herein are circular in shape, one having ordinary skill in the art will recognize that the solder bumps may take any geometry, such as square, rectangular or polygonal.
It is further noted that while a solder redistribution reservoir 32 is square, other geometries for the solder redistribution reservoir are within the scope of the present invention. The different geometries and dimensions of the solder redistribution reservoir may be controlled by various design parameters, such as the amount of solder to be added, the speed of flow, the minimum feature spacing, etc. For instance, as illustrated in FIG. 12, a solder structure 38 includes a U-shaped solder redistribution reservoir 40 of the same width as the solder redistribution reservoir 32 may be utilized in order to provide additional solder to the bump. As another example, a solder structure 50 comprises a bump portion 52 in a plurality of regularly extending solder redistribution reservoirs 54 , as illustrated in FIG. 13 . Thus, by engineering the particular dimensions in shape of the solder redistribution reservoir, the volume, height, and area of the solder bump can be precisely controlled.
It is believed that the solder lines forming the solder redistribution reservoirs may reach a critical length where the efficiency of the solder flow begins to decreases. To improve flow at or near this critical length, and/or to better control the flow rate of the solder, a gradient line width may be utilized, as illustrated in FIGS. 14-16. As shown in FIG. 17, the line width and internal pressure are essentially inversely proportional. Thus, by designing the solder redistribution reservoir to have an increasing line width from a distal end to a proximate end adjacent the bump, the flow rate of the solder will be increased. An increase in the flow rate may be desirable with solder having a wide range of plastic flow so that the solder can be moved before it is completely molten. As illustrated in FIGS. 14 and 15, solder structures 60 and 62 , include solder redistribution reservoir 64 and 66 , respectively, which have continuous line width gradients. It is noted, however, that continuous line width gradients are not necessary for the present invention. The line width gradient may be in only a portion of the solder lines forming the solder redistribution reservoir.
Alternatively, the solder redistribution reservoir may have a line width that decreases from a distal end to a proximate end adjacent the solder bump in order to decrease the flow rate, as illustrated by the solder structure 70 having solder redistribution reservoirs 72 . Slowing the flow rate of the solder in the solder redistribution reservoirs may be desirable in various circumstances, such as with eutectic solders where rapid flow produces instabilities and unpredictability. Specifically, the instability and unpredictability with eutectic solders is caused by a variety of factors, such as not all the solder melting simultaneously, grains of higher melting point alloys, etc.
As discussed above, a small amount of solder remains in the solder redistribution reservoir after reflow. Even though the solder redistribution reservoirs described herein can be shaped and sized to take very little space on a substrate, it may still be desirable to remove the solder redistribution reservoirs after the reflow step. In accordance with the present invention, by inhibiting the complete conversion of the copper (or other wettable metal)layer of the under bump metallurgy to an intermetallic, the remaining copper may be removed in the under bump metallurgy etch step. The removal of the copper allows the residual solder of the solder redistribution reservoir to break off and float away in the under bump metallurgy etchant. A small area of the solder redistribution reservoir may have a narrow width or notch 74 (FIG. 16) which creates a weak point at which the solder reservoir will break off, thereby controlling the breaking point.
By way of example, one method of causing incomplete conversion of the copper in the metallurgy layer is to use a high-lead solder. Another technique involves the use of rapid solder flow, as achievable via the techniques described above, so that there is insufficient tin left in the residual solder in the solder redistribution reservoir to complete the conversion of the copper. However, it is noted that other techniques may be utilized to prevent the complete conversion of the copper, thereby creating a sacrificial copper layer that release the solder redistribution reservoir of the substrate.
Advantageously, solder bumps fabricated utilizing the solder redistribution reservoirs in accordance with the present invention are taller than solder bumps without a solder redistribution reservoir given the same pad diameter and plating thickness. This is particularly advantageous in flip chip designs where it is often difficult to adequately clean the flux and other residue from between the chip and substrate following the reflow step. The incomplete removal of flux and other residue may cause poor adhesion of the underfill epoxies, electrical leakage, or corrosion of metals. If the gap is not sufficiently large between the chip and substrate, then the boundary layer of the cleaning solution would prevent or restrict the flow of the cleaning solution between the chip and substrate.
However, the taller solder bump resulting from the use of the solder redistribution reservoirs will improve the effectiveness of the cleaning solution by increasing the gap between the chip substrate.
The underfill process will likewise benefit from the increased gap size. The underfill epoxy is typically of low viscosity and may not flow between the chip and substrate if the gap is too small. The taller solder bumps provide improved clearance, thereby resulting in better underfill. The structure shown in FIG. 11, when scaled to a pitch of 0.250 mm and plated to a height of 0.050 mm, could be expected to increase the gap from 0.07 mm to 0.100 mm.
Furthermore, the taller the solder bump, the more mechanically reliable the solder bump. This is primarily due to the reduction and strain per unit length discussed above. Of special benefit is the reduction of the strain per unit length to below the elastic limit for the solder. This will eliminate the plastic damage which is the cause of solder fatigue failure.
An advantageous application of the present invention is illustrated in FIGS. 18 and 19, whereby the reliability of electrical connections in a flip chip device are improved. In particular, with reference to FIG. 18, a chip 80 may comprise mechanical bumps 82 which have one or more solder reflow reservoirs 84 in accordance with the present invention associated therewith, and one or more contact solder bump 86 for forming electrical contacts between the chip 80 and a substrate 88 (FIG. 19 ). Given substantially uniform plating thickness across chip 80 , the mechanical bumps 82 will have a greater volume that the contact bumps 86 , and therefore, will be taller. It has been determined that the contact bumps 86 should have a contact pad 90 as equal to or larger than the contact pads 92 associated with the mechanical bumps 82 . By using contact pads of the same size or larger with the contact bumps 86 , the mechanical bumps 82 will not grow larger that the contact bumps 86 until the contact bumps 86 have soldered to the substrate 88 . Alternatively, the flow rate of the soldered to the mechanical bumps 86 from the solder redistribution reservoir may be slowed using a solder redistribution reservoir of a suitable dimension and shape, as described above. As shown in FIG. 19, the taller mechanical bumps 82 create a larger gap or opening between the chip 80 and substrate 88 , which stretches the contact bumps 86 . As discussed above, the elongated contact bumps 86 are more reliable because the strain per unit length is reduced. It is noted that the bump designs and configurations of FIGS. 18 and 19 are merely exemplary of a bump and associated solder redistribution reservoir which can be utilized to stretch or elongate a contact bump to improve the reliability of the contact bump.
In yet another advantageous application of the present invention, an improved vacuum may be formed in a sealed chamber, as illustrated in FIGS. 20A-20C, and 21 . In particular, a lid or cap 102 is patterned with a soldered seal ring 104 for bonding with a substrate 106 for creating a sealed chamber 108 . In the embodiment illustrated, a second seal ring 110 is provided for redundancy and improved reliability, though it is not necessary for the present invention, as best illustrated in FIG. 21 . Nonetheless, the second seal ring 110 reduces the pressure differential across the first seal ring 104 . Associated with each seal ring 104 , 110 is at least one solder redistribution reservoir 112 in accordance with the present invention. While the solder redistribution reservoirs 112 are rectangular in the illustrative embodiment, it is recognized that the solder redistribution reservoirs can be shaped and sized as described herein to achieve a desired result.
A microelectromechanical system (MEMS) device 112 , or other device favoring a vacuum environment, is disposed inside the chamber 108 . While the MEMS device 112 is shown fabricated on the substrate 106 , it will be recognized by those of ordinary skill in the art that the MEMS device can be fabricated on either or both the lid 102 and the substrate 106 .
On the substrate, bonding regions 114 are provided in the form of a metalization or other conventional solder wettable material for bonding to the respective solders seal rings 104 , 110 . The fabrication of the bonding regions is well known and need not be described further herein. Alternatively, solder dams may be utilized, as with cap 102 . It is noted that the solder seal rings 104 , 110 may be square as shown, or alternatively, circular, rectangular, polygonal, or any other shape.
With particular reference to FIGS. 20A-20C, the cap 102 is initially plated with solder seal rings 104 , 110 . The cap 102 is then placed on the substrate 106 so that the solder ring aligns with the solder wettable pads on the substrate 106 . This procedure is preferably performed in a vacuum environment so that the resulting chamber 108 is at the pressure of the vacuum environment. Upon reflow, the solder seal rings 104 , 110 increase in size with the additional solder from the solder redistribution reservoirs, thereby expanding the volume of the chamber 108 . The increase in volume decreases the pressure in the chamber 108 . Thus, the pressure in the chamber 108 will be less than that of the vacuum environment in which it was sealed.
As an example, using the increase in gap height given above, the gap volume will increase from 0.070 mm*A, where A is the area enclosed by the seal ring, to 0.1 mm*A, The volume increase is then 10/7 or 1.43 times greater. Since pressure is inversely proportional to volume, the pressure will be 30% lower than without the increased gap.
In the drawings and specification, there have been disclosed typical preferred embodiments of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only, and not for the purposes of limitation; the scope of the invention being set forth in the following claims. | A controlled-shaped solder reservoir provides additional solder to a bump in the step for increasing the volume of solder forming the solder bump. The controlled shaped reservoirs can be shaped and sized to provide predetermined amounts of solder to the solder bump. Thus, the height of the resulting solder bump can be predetermined. The solder reservoirs can be shaped to take a minimum amount of space, such as by at least partially wrapping around the solder bump. Consequently, the solder bumps may have increased height without adding to the space requirements of the solder bump, or without increasing the fabrication cost. In addition, due to the finite time required for solder flow, a means of sequencing events during soldering is provided. | 8 |
DESCRIPTION OF THE RELATED ART
[0001] This application is a continuation of prior U.S. Ser. No. 10/264,298, filed Oct. 2, 2002, now issued as U.S. Pat. No. 6,726,028, which claimed priority from U.S. Provisional Application No. 60/326,805, filed Oct. 2, 2001.
[0002] Disc or roll screens are used in the materials handling industry for screening flows of materials to remove certain items of desired dimensions. Disc screens are particularly suitable for classifying what is normally considered debris or residual materials. This debris may consist of soil, aggregate, asphalt, concrete, wood, biomass, ferrous and nonferrous metal, plastic, ceramic, paper, cardboard, paper products or other materials recognized as debris throughout consumer, commercial and industrial markets. The function of the disc screen is to separate the materials fed into it by size or type of material. The size classification may be adjusted to meet virtually any application.
[0003] Disc screens have a problem effectively separating Office Sized Waste Paper (OWP) since much of the OWP may have similar shapes. For example, it is difficult to effectively separate notebook paper from Old Corrugated Cardboard (OCC) since each is long and relatively flat.
[0004] Accordingly, a need remains for a system that more effectively classifies material.
SUMMARY OF THE INVENTION
[0005] Multiple shafts are aligned along a frame and configured to rotate in a direction causing paper products to move along a separation screen. The shafts are configured with a shape and spacing so that substantially rigid or semi-rigid paper products move along the screen while non-rigid or malleable paper products slide down between adjacent shafts.
[0006] In one embodiment, the screen includes at least one vacuum shaft that has a first set of air input holes configured to suck air and retain the non-rigid paper products. A second set of air output holes are configured to blow out air to dislodge the paper products retained by the input holes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] [0007]FIG. 1 is a schematic showing a single-stage de-inking screen.
[0008] [0008]FIG. 2 is a schematic showing a dual-stage de-inking screen.
[0009] [0009]FIG. 3 is a schematic showing an isolated view of vacuum shafts used in the de-inking screens shown in FIGS. 1 or 2 .
[0010] [0010]FIG. 4 is schematic showing an isolated view of a plenum divider that is inserted inside the vacuum shaft shown in FIG. 3.
[0011] [0011]FIGS. 5A-5C show different discs that can be used with the de-inking screen.
[0012] [0012]FIG. 6 is a plan view showing an alternative embodiment of the de-inking screen.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Referring to FIG. 1, a de-inking screen 12 mechanically separates rigid or semi-rigid paper products constructed from cardboard, such as Old Corrugated Containers (OCC), kraft (small soap containers, macaroni boxes, small cereal boxes, etc.) and large miscellaneous contaminants (printer cartridges, plastic film, strapping, etc.) 14 from malleable or flexible office paper, newsprint, magazines, journals, and junk mail 16 (referred to as de-inking material).
[0014] The de-inking screen 12 creates two material streams from one mixed incoming stream fed into an in feed end 18 . The OCC, kraft, and large contaminants 14 are concentrated in a first material stream 20 , while the de-inking material 16 is simultaneously concentrated in a second material stream 22 . Very small contaminants, such as dirt, grit, paper clips, etc. may also be concentrated with the de-inking material. 16 . Separation efficiency may not be absolute and a percentage of both materials 14 and 16 may be present in each respective material stream 20 and 22 after processing.
[0015] The separation process begins at the in feed end 18 of the screen 12 . An in feed conveyor (not shown) meters the mixed material 14 and 16 onto the de-inking screen 12 . The screen 12 contains multiple shafts 24 mounted on a frame 26 with brackets 28 so as to be aligned parallel with each other. The shafts 24 rotate in a forward manner propelling and conveying the incoming materials 14 and 16 in a forward motion.
[0016] The circumference of some of the shafts 24 may be round along the entire length, forming continuous and constant gaps or openings 30 along the entire width of the screen 12 between each shaft 24 . The shafts 24 in one embodiment are covered with a rough top conveyor belting to provide the necessary forward conveyance at high speeds. Wrappage of film, etc. is negligible due to the uniform texture and round shape of the rollers. Alternatively, some of the shafts 24 may contain discs having single or dual diameter shapes to aide in moving the materials 14 and 16 forward. One disc screen is shown in FIG. 6.
[0017] The distance between each rotating shaft 24 can be mechanically adjusted to increase or decrease the size of gaps 30 . For example, slots 32 in bracket 28 allow adjacent shafts 24 to be spaced apart at variable distances. Only a portion of bracket 28 is shown to more clearly illustrate the shapes, spacings and operation of shafts 24 . Other attachment mechanisms can also be used for rotatably retaining the shafts 24 .
[0018] The rotational speed of the shafts 24 can be adjusted offering processing flexibility. The rotational speed of the shafts 24 can be varied by adjusting the speed of a motor 34 or the ratio of gears 36 used on the motor 34 or on the screen 12 to rotate the shafts 24 . Several motor(s) may also be used to drive different sets of shafts 24 at different rotational speeds.
[0019] Even if the incoming mixed materials 14 and 16 may be similar in physical size, material separation is achieved due to differences in the physical characteristics of the materials. Typically, the de-inking material 16 is more flexible, malleable, and heavier in density than materials 14 . This allows the de-inking material 16 to fold over the rotating shafts 24 A and 24 B, for example, and slip through the open gaps while moving forward over the shafts 24 .
[0020] In contrast, the OCC, kraft, and contaminants 14 are more rigid, forcing these materials to be propelled from the in feed end 18 of screen 12 to a discharge end 40 . Thus, the two material streams 20 and 22 are created by mechanical separation. The de-inking screen 12 can be manufactured to any size, contingent on specific processing capacity requirements.
[0021] [0021]FIG. 2 shows a two-stage de-inking screen 42 that creates three material streams. The first stage 44 releases very small contaminants such as dirt, grit, paper clips, etc. 46 through the screening surface. This is accomplished using a closer spacing between the shafts 24 in first stage 44 . This allows only very small items to be released through the relatively narrow spaces 48 .
[0022] A second stage 50 aligns the shafts 24 at wider spaces 52 compared with the spaces 48 in first stage 48 . This allows de-inking materials 58 to slide through the wider gaps 52 formed in the screening surface of the second stage 50 as described above in FIG. 1.
[0023] The OCC, kraft, and large contaminants 56 are conveyed over a discharge end 54 of screen 42 . The two-stage screen 42 can also vary the shaft spacing and rotational speed for different types of material separation applications and different throughput requirements. Again, some of the shafts 24 may contain single or dual diameter discs to aide in moving the material stream forward along the screen 42 (see FIG. 6).
[0024] The spacing between shafts in stages 44 and 50 is not shown to scale. In one embodiment, the shafts 24 shown in FIGS. 1 and 2 are generally twelve inches in diameter and rotate at about 200-500 feet per minute conveyance rate. The inter-shaft separation distance may be in the order of around 2.5-5 inches. In the two-stage screen shown in FIG. 2, the first stage 44 may have a smaller inter-shaft separation of approximately 0.75-1.5 inches and the second stage 50 may have an inter-shaft separation of around 2.5-5 inches. Of course, other spacing combinations can be used, according to the types of materials that need to be separated.
[0025] Referring to FIGS. 2, 3 and 4 , vacuum shafts 60 may be incorporated into either of the de-inking screens shown in FIG. 1 or FIG. 2. Multiple holes or perforations 61 extend substantially along the entire length of the vacuum shafts 60 . In alternative embodiments, the holes 61 may extend only over a portion of the shafts 60 , such as only over a middle section.
[0026] The vacuum shafts 60 are hollow and include an opening 65 at one end for receiving a plenum divider assembly 70 . The opposite end 74 of the shaft 60 is closed off. The divider 70 includes multiple fins 72 that extend radially out from a center hub 73 . The divider 70 is sized to insert into the opening 65 of vacuum shaft 60 providing a relatively tight abutment of fins 72 against the inside walls of the vacuum shaft 60 . The divider 70 forms multiple chambers 66 , 68 and 69 inside shaft 60 . In one embodiment, the divider 70 is made from a rigid material such as steel, plastic, wood, or stiff cardboard.
[0027] A negative air flow 62 is introduced into one of the chambers 66 formed by the divider 70 . The negative air flow 62 sucks air 76 through the perforations 61 along a top area of the shafts 60 that are exposed to the material stream. The air suction 76 into chamber 66 encourages smaller, flexible fiber, or de-inking material 58 to adhere to the shafts 60 during conveyance across the screening surface.
[0028] In one embodiment, the negative air flow 62 is restricted just to this top area of the vacuum shafts 60 . However, the location of the air suction portion of the vacuum shaft 60 can be repositioned simply by rotating the fins 72 inside shaft 60 . Thus, in some applications, the air suction portion may be moved more toward the top front or more toward the top rear of the shaft 60 . The air suction section can also be alternated from front to rear in adjacent shafts to promote better adherence of the de-inking material to the shafts 60 .
[0029] The negative air flow 62 is recirculated through a vacuum pump 78 (FIG. 3) to create a positive air flow 64 . The positive air flow 64 is fed into another chamber 68 of the vacuum shafts 60 . The positive air flow 64 blows air 80 out through the holes 61 located over chamber 68 . The blown air 80 aides in releasing the de-inking material 58 that has been sucked against the holes of negative air flow chamber 66 . This allows the de-inking material 58 to be released freely as it rotates downward under the screening surface. In one embodiment, the blow holes over chamber 68 are located toward the bottom part of the vacuum shaft 60 .
[0030] The second stage 50 (FIG. 2) releases the de-inking material 58 through the screen surface. The stiffer cardboard, OCC, kraft, etc. material 56 continues over the vacuum shafts 60 and out over the discharge end 54 of the screen 42 . The two-stage de-inking screen 42 can also vary shaft and speed.
[0031] [0031]FIGS. 5A-5C show different shaped discs that can be used in combination with the de-inking screens shown in FIGS. 1 and 2. FIG. 5A shows discs 80 that have perimeters shaped so that space D sp remains constant during rotation. In this example, the perimeter of discs 80 is defined by three sides having substantially the same degree of curvature. The disc perimeter shape rotates moving materials in an up and down and forward motion creating a sifting effect that facilitates classification.
[0032] [0032]FIG. 5B shows an alternative embodiment of a five-sided disc 82 . The perimeter of the five-sided disc 82 has five sides with substantially the same degree of curvature. Alternatively, any combination of three, four, five, or more sided discs can be used.
[0033] [0033]FIG. 5C shows a compound disc 84 that can also be used with the de-inking screens to eliminate the secondary slot D sp that extends between discs on adjacent shafts. The compound disc 84 includes a primary disc 86 having three arched sides. A secondary disc 88 extends from a side face of the primary disk 86 . The secondary disc 88 also has three arched sides that form an outside perimeter smaller than the outside perimeter of the primary disc 86 .
[0034] During rotation, the arched shapes of the primary disc 86 and the secondary disc 88 maintain a substantially constant spacing with similarly shaped dual diameter discs on adjacent shafts. However, the different relative size between the primary discs 86 and the secondary discs 88 eliminate the secondary slot D sp that normally exists between adjacent shafts for single diameter discs. The discs shown in FIGS. 5A-5C can be made from rubber, metal, or any other fairly rigid material.
[0035] [0035]FIG. 6 shows how any of the discs shown in FIGS. 5A-5C can be used in combination with the de-inking shafts previously shown in FIGS. 1 and 2. For example, FIG. 6 shows a top view of a screen 90 that includes set of de-inking shafts 24 along with a vacuum shaft 60 and several dual diameter disc shafts 92 . The different shafts can be arranged in any different combination according to the types of materials that need to be separated.
[0036] The primary discs 86 on the shafts 92 are aligned with the secondary discs 88 on adjacent shafts 92 and maintain a substantially constant spacing during rotation. The alternating alignment of the primary discs 86 with the secondary discs 88 both laterally across each shaft and longitudinally between adjacent shafts eliminate the rectangular shaped secondary slots that normally extended laterally across the entire width of the screen. Since large thin materials can no longer unintentionally pass through the screen, the large materials are carried along the screen and deposited in the correct location with other oversized materials.
[0037] The dual diameter discs 84 , or the other single discs 80 or 82 shown in FIG. 5A and 5B, respectively, can be held in place by spacers 94 . The spacers 94 are of substantially uniform size and are placed between the discs 84 to achieve substantially uniform spacing. The size of the materials that are allowed to pass through openings 96 can be adjusted by employing spacers 94 of various lengths and widths.
[0038] Depending on the character and size of the debris to be classified, the diameter of the discs may vary. Again, depending on the size, character and quantity of the materials, the number of discs per shaft can also vary. In an alternative embodiment, there are no spacers used between the adjacent discs on the shafts.
[0039] It will be understood that variations and modifications may be effected without departing from the spirit and scope of the novel concepts of this invention. | Multiple shafts are aligned along a frame and configured to rotate in a direction causing paper products to move along a separation screen. The shafts are configured with a shape and spacing so that substantially rigid pieces of the paper products move along the screen while non-rigid pieces of the paper products slide down between adjacent shafts. In one embodiment, the screen includes at least one vacuum shaft that has a first set of air input holes configured to suck air and retain the non-rigid paper products. A second set of air output holes are configured to blow out air to dislodge the paper products retained by the input holes. | 3 |
BACKGROUND OF THE INVENTION
Ring travelers are used in the winding of yarn on a bobbin. A spindle carrying the bobbin revolves at a high speed and carries an end of yarn with it. A traveler is mounted on the circular track of a stationary ring surrounding the bobbin. The yarn is threaded through the traveler and causes it to revolve at high speed on the circular track of the ring. The friction generated by the high speed of the traveler causes the traveler to deteriorate and become inoperative and require replacement after a period of use.
The prior art contains many attempts to reduce friction and prolong the life of the traveler. See, for example, the following U.S. Pat. Nos.:
588,817: George O. Draper, Aug. 24, 1897
2,198,636: Louis W. Schoaff, Apr. 30, 1940
2,320,213: Maurice L. Bolton, May 25, 1943
2,756,558: William M. Camp et al., July 31, 1956
3,368,342: Johann Kaiser, Feb. 13, 1968
3,373,557: Chester L. Loveland, Mar. 19, 1968
3,995,419: Robert L. Goerens, Dec. 7, 1976
Many of these structures have enjoyed a measure of success, but friction and wear are inherent in the function of the traveler and there remains room for improvement in the field.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a ring traveler so constructed that it will slide around the ring with minimal friction and which can be reused by repositioning the yarn at a different position on the traveler.
It is a more specific object of the invention to provide a ring traveler having the usual shank and upper and lower hooks extending about respective upper and lower flanges of a vertically reciprocable ring, and said traveler including at least one yarn passageway projecting from the surface of the shank opposite the hooks. The yarn passageway is located midway between the free ends of the hooks of the traveler so that a yarn extending through the yarn passageway equalizes the pressure of the hooks against the ring as the traveler traverse the ring.
There are two yarn passageways on the back of the traveler in one embodiment of the invention, it being intended for the yarn to be positioned in a second passageway after the first one has become undesirably worn. Convenient access to the yarn passageway on the back of the traveler is provided in each embodiment of the present invention without having to remove the traveler from the ring and without having to thread the end of the yarn through the passageway.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary side elevation, partially in section and with parts broken away, of a bobbin, ring rail, ring and traveler, illustrating the environment of the present invention;
FIG. 1A is a fragmentary view similar to FIG. 1 showing the same traveler repositioned on the ring and with the yarn passing through a second position on the traveler;
FIG. 2 is a perspective view looking at the top, back and one side of one embodiment of the invention;
FIG. 3 is a side view of the traveler shown in FIG. 2;
FIG. 4 is an end view of the traveler shown in FIG. 2;
FIG. 5 is a rear view of the traveler shown in FIG. 2;
FIG. 6 is an end view similar to FIG. 4 but illustrating a modified form of the invention;
FIG. 7 is a front view of the traveler shown in FIG. 6;
FIG. 8 is a side view of a third embodiment of the invention;
FIG. 9 is a rear view of the traveler shown in FIG. 8;
FIG. 10 is an environmental view similar to FIG. 1, but illustrating the traveler of FIG. 8 with yarn passing through a first position on the traveler;
FIG. 11 is a view similar to FIG. 10 showing the same traveler continuing in use after the first position has become undesirably worn, and with the yarn passing through a second position on the traveler;
FIG. 12 is another view similar to FIG. 10 showing the same traveler continuing in use after the second position has become undesirably worn, and with the traveler repositioned on the ring and with the yarn passing through a third position on the traveler;
FIG. 13 is a side view of a fourth embodiment of the invention;
FIG. 14 is a rear view of the traveler shown in FIG. 13;
FIG. 15 is an environmental view similar to FIG. 1, but illustrating the traveler of FIG. 13 with yarn passing through a first position on the traveler;
FIG. 16 is a view similar to FIG. 15 showing the same traveler continuing in use after the first position has become undesirably worn, and with the yarn passing through a second position on the traveler; and
FIG. 17 is another view similar to FIG. 15 showing the same traveler continuing in use after the second position has become undesirably worn, and with the traveler repositioned on the ring and with the yarn passing through a third position on the traveler.
DETAILED DESCRIPTION OF THE INVENTION
Referring more specificially to the drawings, a bobbin 10 is mounted for rotation with a spindle 11 and within a vertically reciprocable ring rail 12. A guide or spinning ring 13 is mounted in the ring rail 12 is surrounding relation to the bobbin 10. The guide ring 13 has upper and lower flanges 14 and 15 and a web 18. Yarn 16 extends through an eyelet 17 above the bobbin 10 through an ear-shaped traveler 20, mounted on the ring 13, to the bobbin 10.
The traveler 20 includes a shank 21 extending between rounded ends 22 and 23 terminating in respective horns 24, 25 extending inwardly toward each other and about the flanges 14 and 15 of the ring 13. The traveler 20 slides rapidly around the ring as the bobbin 10 rotates with the spindle 11 to wind the yarn 16 on the bobbin.
The friction generated by the traveler moving along the stationary ring causes the surface of the traveler to become worn after usage, but the amount of friction and consequently the amount of wear, is reduced by initially positioning the yarn of the traveler so that the yarn tension equalizes the pressure of the horns 24 and 25 against respective flanges 14, 15 on the ring 13.
Generally speaking, a traveler's function is to change the vertical direction of an incoming yarn to a horizontal direction as the yarn approaches the bobbin, and to impose on the yarn a certain tension. The amount of tension is important and varies from yarn to yarn, but in all cases it is critical that the tension be uniform. The friction of the traveler on the ring and the friction of the yarn on the traveler changes, causing a change in tension, when the traveler becomes worn and engages the ring at a different attitude, as when the traveler edges or assumes an inclined position relative to the ring. This occurs because different forces act on the traveler as the traveler slides around the ring at high speeds. These are the forces resulting from the tension of the yarn, both horizontally inwardly toward the bobbin at the center of the ring and vertically upwardly from the ring toward the source of the yarn. Additionally, the rapid movement of the traveler around the ring subjects it to centrifugal forces urging the traveler radially outwardly of the ring. Consequently, the traveler has predetermined zones facing the ring which are subject to increased loads and hence, to greater wear. The traveler of this invention equalizes the pressure on the zones of the traveler subject to wear and enables a traveler to be reused by repositioning the traveler and/or the yarn after first zones of wear have undesirably changed the yarn tension, thereby prolonging the useful life of the traveler.
According to the invention, the traveler 20 is made of a synthetic material, nylon for example, and the embodiment of FIGS. 2 through 5 includes a first shoulder 30 merging as at 31 with the back or outer surface 32 of the shank 21. The shoulder 30 curves outwardly and upwardly in FIG. 2 and terminates in a finger portion 33 spaced from the back surface 32 of the shank 21. The shoulder 30 and its finger 33 define a yarn passageway 34 and the space 35 between the finger 33 and shank 21 provides access to the passageway 34 through which a medial portion P of yarn 16 may be readily passed.
A second shoulder 36 merges as at 37 with the back or rear surface 32 of shank 21 and curves outwardly and downwardly therefrom, terminating in a finger portion 38 spaced from the rear surface 32. The shoulder 36 and its finger 38 define a second yarn passageway 40 concentric with the yarn passageway 34. A space 41 between the finger 38 and the back surface 32 provides access to the passageway 40 and a space 42 between the shoulders 30 and 36 (FIGS. 4 and 5) permits free passage of a medial portion P of yarn 16 to the passageway 40 or 34, as desired.
Referring to FIG. 1, the traveler 20 is mounted on the ring 13 with the finger 38 of shoulder 36 pointing downwardly and with the yarn 16 positioned in the passageway 40 between finger 38 and shank 21 of the traveler. The tension on the yarn and the speed of the traveler creates friction between the yarn and the zone of the traveler near the merge line 37 of shoulder 36 so that this zone of the traveler is subjected to wear during use. The yarn passageway 40 located midway between the free ends of the horns 24, 25 tends to equalize the horizontal forces causing frictional resistance between the ring and the wear zones on the horns 24, 25, but the vertical forces on the yarn pulls the bottom portion and horn 25 of the traveler 20 against the bottom flange 15, causing more wear on that zone than is experienced at the top of the traveler.
When these zones of the traveler become sufficiently worn to affect the tension on the yarn, the traveler need not be replaced, as has been the practice, but it can continue in use by removing the yarn from the passageway 40 through the spaces 41 and 42 and repositioning the traveler 20 on the ring with the finger 33 of shoulder 30 pointing downwardly and with the relatively unworn horn 24 extending about the lower flange 15 as in FIG. 1A. The yarn 16 is then repositioned in passageway 34 by passing a medial portion P through the spaces 35 and 42. Operation is then resumed with new wear zones of the traveler 20 engaging the ring and the yarn, and the life of the traveler is thereby increased.
A modified form of the invention is illustrated in FIGS. 6 and 7 wherein like parts of the traveler are represented by the same reference number as heretofor used and the different parts bear the same reference number with the prime notation added. The traveler 20 1 of FIGS. 6 and 7 differs from the embodiment illustrated in FIGS. 1 through 5 in that the fingers 33 1 and 38 1 of respective shoulders 30 1 , 36 1 on traveler 20 1 extend laterally beyond the sides of the traveler to provide spaces 35 1 and 41 1 which facilitate positioning of a medial portion P of the yarn 16 in the passageways 34 and 40 defined by the shoulders and fingers. The traveler 20 1 of FIGS. 6 and 7 is positioned on the ring and may be repositioned on the ring 13 in the same manner as previously described in connection with the traveler of FIGS. 1 through 5.
FIGS. 8 through 12 illustrate a further embodiment of the traveler, broadly indicated at 50. The traveler 50 includes a shank 51 extending between squared ends 52 and 53 terminating in respective horns 54 and 55 extending inwardly toward each other. A shoulder 56 projects from the rear wall 57 of spline 51. A finger 58 curves downwardly and inwardly from the rear portion 59 of shoulder 56, terminating in a free end 60 in closely spaced relation to an abutment 61 extending rearwardly from the back wall 57 of spline 51. The finger 58 and shoulder 59 cooperate with the back wall 57 to define a yarn passageway 62 with the space 63 between the free end 60 of finger 58 and the abutment 61 providing a restricted access for a medial portion P of yarn 16 into the passageway 62.
FIGS. 9, 10 and 11 illustrate an initial position and successively different positions of the yarn 16 on the traveler 50 as the same traveler is reused to guide yarn 16 onto the rotating bobbin 10 after preceding wear zones on the traveler have deteriorated, jeopardizing the uniformity of the tension.
In FIG. 9, the traveler is mounted on the ring 13 in an initial position with the squared end 52 and its horn 54 extending about the upper flange 14 and the squared end 53 and its horn 55 extending about the lower flange 15 of the ring 13. A medial portion P of the yarn 16 has been moved through the space 63 between finger 58 and abutment 61 into the passageway 62. So positioned, the horizontal forces of the tensioned yarn 16 tend to equalize the pressure on the horns 54, 55 against their respective flanges 14 and 15 sufficiently that those wear zones out last the wear zone at the passageway 62 where the yarn rubs against the traveler. The traveler 50 can continue to be used after the wear zone at passageway 62 jeopardizes the uniformity of tension by removing the yarn from the passageway 62 and repositioning the yarn 16 over the horn 54 in engagement with the zone 63 at the upper inner surface of traveler 50 adjacent the juncture of spline 57 with squared end 52 (FIG. 11).
The traveler 50 may be used a third time after the yarn 16 undesirably wears away the zone 63 by repositioning the traveler 50 and the ring 13 so the squared end 53 and its horn 55 extend about the upper flange 14 and the squared end 52 and its horn 54 extend about the lower flange 15 of ring 13 (FIG. 12). The yarn 16 is then passed over horn 55 and into engagement with zone 64 at the inner surface of traveler 50 adjacent the juncture of spline 57 and squared end 53 in FIG. 12. When the zone 64 at squared end 53 becomes undesirably worn, the traveler 50 must be discarded and replaced with a new traveler. The traveler 50 will have, however, lasted longer than the prior art travelers and will have contributed to increased production because of the relative ease of positioning and repositioning the yarn in the passageway 62 and zones 63 and 64.
A further embodiment of the traveler is generally indicated at 70 in FIGS. 12 through 16. Traveler 70 has rounded ends 71 and 72 terminating in respective horns 73 and 74. The rounded end portions 71 and 72 are connected by a spline 75 formed integral therewith and projecting forwardly at 75A and 75B toward the horns 73, 74 from the juncture of the spline 75 with the rounded end portions 71 and 72 (FIG. 13). The inwardly projecting spline 75 is positioned between the flanges 14 and 15 on the ring 13 and in closely spaced relation to or against the web 18 of ring 13. The inner configuration of the spline 75 and the circles 77 and 78 defined by the rounded end portions 71 and 72 generally conform to the cross-sectional configuration of the ring 13 and the proximity of the spline 75 to the web 18 of the ring results in the spline 75 engaging the web as the traveler slides along the ring, thereby stablizing the traveler and limiting the frictional wear at the zones of the horns 73 and 74.
The traveler 70 is specifically designed to be used and re-used with the yarn positioned to engage the traveler at different positions. A finger 79 extending downwardly from the rounded end portion 71 in rearwardly spaced relation to the spline 75 and terminating at 80 in spaced relation to the rounded end portion 72 defines a yarn passageway 81 (FIG. 13). The upper end 82 of the yarn passageway 81 is in the medial portion of the traveler 70 between its horns 73 and 74.
It is intended that the first use of the traveler be with the yarn 16 positioned in the passageway 81 and engaging the traveler at the inner end 82 of the passageway (FIG. 15). As in the previously described forms of the invention, the medial location of the passageway 81 equalizes the pressure on the horns and minimizes excessive frictional wear of one horn over the other. Eventually, however, the friction of the yarn traversing the passageway 81 will undesirably wear that zone of the traveler adjacent the inner end 82 of the passageway. When this happens, the yarn is removed from the passageway 81 moving a medial part of the yarn past the free end 80 of finger 79 and repositioning the yarn on the traveler by drawing a medial portion of the yarn past the horn 73 to engage the zone 83 on the inner surface of the rounded end portion 71 adjacent the spline portion 75A (FIG. 16). In due course, the friction of the yarn moving against the zone 83 will undesirably wear the zone 83 for effective use and at that time the yarn 16 may be repositioned to engage zone 84 on the inner surface of the traveler adjacent the juncture of spline portion 75B and end portion 72, after the traveler has been repositioned on the ring 13 as shown in FIG. 17.
The engagement of the bulbous spline 75 with the web 13 of the ring is effective in the positions of FIGS. 16 and 17 to stablize the traveler and equalize the wear on the zones adjacent horns 73 and 74, and contributes to those zones continuing to be productive as the yarn is positioned in successively usable zones 82, 83 and 84.
There is thus provided an improved traveler which is structured to equalize the wear on the parts of the traveler engaging a ring and which is structured to receive the yarn in different operative positions or zones on the traveler to prolong the useful life of the traveler.
Although specific terms have been used in descriping the invention, they are used in a descriptive and generic sense only and not for purposes of limitation. | A universal traveler is provided for ring spinning machines, the traveler being structured to permit repositioning of the traveler on the ring after a portion of the traveler has been worn. | 3 |
THE FIELD OF THE INVENTION
The present invention relates to sweeping machines and more specifically to what are known in the art as over-the-top sweepers. In such machines, the main sweeping brush throws debris up and over the top of the brush into a debris hopper behind the brush, rather than throwing debris directly forward into a hopper in front of the brush in what is known as a forward throw sweeper. More particularly, the present invention relates to a movable recirculation flap which is positioned between the rear periphery of the brush and the debris hopper.
Conventional over-the-top sweepers have what is known as a recirculation flap which slopes down and forward at about a 45 degree angle and is located immediately behind the main brush and between the rear periphery of the brush and the debris hopper. All sweepers tend to throw some debris over the brush. This debris would drop to the floor behind the brush and be lost, except that the recirculation flap directs it forward into the sweeping zone of the brush, so it will be swept up a second time and loaded into the hopper. A forward throw sweeper throws only a small part of the total debris over the brush, but an over-the-top sweeper throws all of it over the brush, and a percentage of such debris will drop between the brush and the front wall of the hopper. Thus, an effective recirculation flap is very important in an over-the-top sweeper.
Normally, it is important to maintain a small clearance on the order of 1/4" or so between the rear periphery of the brush and the recirculation flap. It is also important to maintain this clearance as the brush wears down to a smaller diameter. brush is considered to be worn down to an extent for replacement when its diameter is 8". As this wear occurs, the clearance between the brush and a fixed recirculation flap will inevitably increase, which will dramatically reduce the sweeping efficiency of the machine. The present invention solves this problem by having a movable recirculation flap, which recirculation flap is moved concurrently with adjustment of the position of the brush relative to a surface to be swept.
The main sweeping brush is mounted between a pair of brush arms which are pivotally mounted on the machine chassis. The brush arms are moved by a control lever accessible to the operator. Thus, the operator can control the position of the brush relative to the surface it is sweeping. Mounted on one of the brush arms is a lever which is in contact, through an intermediate lever, with an arm that extends out from the pivotal recirculation flap. The result of the interconnection described is that movement of the brush toward and away from a surface to be swept provides concurrent movement of the recirculation flap toward and away from the rear periphery of the sweeping brush, to the end that the gap between the brush and the recirculation flap remains essentially constant.
SUMMARY OF THE INVENTION
The present invention relates to sweeping machines of the type known as over-the-top sweepers and more particularly to a movable recirculation flap for such a machine.
A primary purpose of the invention is to provide a recirculation flap for use in the described environment which is moved concurrently with adjustment of brush position relative to the surface being swept.
Another purpose of the invention is to provide an over-the-top sweeper having a movable recirculation flap which moves concurrently with brush adjustment to maintain an essentially constant gap between the flap and the rear of the sweeping brush.
Another purpose is an over-the-top sweeper having a manual control to adjust brush position relative to the surface being swept, which manual control simultaneously moves a recirculation flap immediately behind the brush to maintain a constant flap/brush gap.
Other purposes will appear in the ensuing specification, drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated diagrammatically in the following drawings wherein:
FIG. 1 is a side view, with portions broken away, of an over-the-top sweeping machine;
FIG. 2 is an enlarged partial side view illustrating the main sweeping brush and the mechanisms for moving the front flap and recirculation flap;
FIG. 3 is an enlarged partial side view, similar to FIG. 2, showing the recirculation flap in a second position;
FIG. 4 is an exploded perspective illustrating the foot pedal and its connection to the front flap;
FIG. 5 is an enlarged side view illustrating the foot pedal and the front flap in a partially raised position; and
FIG. 6 is a side view, similar to FIG. 5, illustrating the foot pedal and front flap in a full raised position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention relates to sweeping machines and more specifically to what is known in the art as an over-the-top sweeper in that the debris is moved over the top of the brush as it transfers to the debris hopper which is located behind the brush.
In FIG. 1, the sweeper includes a chassis 10 having a front control module 12 mounting a steering wheel 14 and a control lever 16. There is an operator seat 18 and a control lever 20 for use in changing the position of the sweeping brush relative to the surface being cleaned. A foot pedal 22 is pivotally mounted, as at 24, to the chassis 10, as will be described in more detail hereinafter. The chassis 10 is mounted on wheels 26 and may include front side brushes 28 and a main sweeping brush 30. Directly behind the brush 30 is a debris hopper 32. The brush 30 will have a conventional drive mechanism, not shown herein, but common on machines of this type.
The main sweeping brush 30 is mounted for rotation between a pair of arms, one of which is indicated at 34. Each of the arms 34 will pivot about a pivotal mounting 36. The two arms are joined together in a torsionally rigid manner by a cross bar indicated at 37, and suitable fasteners, not shown. One arm 34 is attached to a link 38 by means of a fastener 40, midway of the link 38, and a fastener 42 at the lower end of the link 38, with the fastener 42 being located in an elongated slot 44. The upper end of link 38 is pivotally attached to an arm 46, which in turn is pivotally attached to the control lever 20. The lever 20 pivotally mounts the arm 46 intermediate its opposite ends, as at 48, and the lever 20 is pivotally attached to the chassis 10, as at 50. Thus, as shown in FIG. 2, pivotal movement of the lever 20 counterclockwise about its pivot point 50 has the effect of rotating the brush arms 34 about pivot point 36 in a counterclockwise direction. This movement is necessary to lower the brush as it becomes worn. Conventionally, sweeping brushes may wear from an 11" new diameter to an 8" worn diameter before the brush is discarded. In order to maintain the brush at the proper orientation relative to the surface to be cleaned, it is periodically lowered by the operator through manipulation of the lever 20. The above-described mechanism controls movement of the brush so that it is maintained in the proper location for sweeping.
Over-the-top sweepers throw all of the debris moved by the brush over the top of the brush and a percentage of such debris will drop between the brush and the front wall of the hopper. This dictates that a recirculation lip or flap be located directly behind the brush and that there be minimal clearance between the brush and the recirculation flap. Such clearance is preferably on the order of 1/4" and must be maintained even when the brush is worn to a smaller diameter. The entrance into the debris hopper 32 is indicated at 52 and it is directly behind the brush 30. The recirculation flap is indicated generally at 54 and is located below and to the rear of the brush 30.
The flap 54 is made of a rubber or rubber-like material and has two side walls, one of which is indicated at 58. Flap 54 is attached to a support plate 60 by bolts and a retainer strip 61. Plate 60 is bolted to a second support plate 63, which has a round rod 62 welded along its upper edge. A "living hinge" 65, made of flexible rubber or rubber-like material, extends along support plate 63 and contributes to sealing the area against dust leakage. Rod 62 is journaled in portions of chassis 10, and the recirculation flap assembly as described here can pivot about it. Rod 62 includes a bent end 64 which extends upwardly and forwardly and is in contact with a T-shaped lever 68. The lever 68 is pivoted, as at 70, to a portion of the chassis 10 and has an upper end 72 in contact with an arm 74 which is bolted, as at 76, to the brush support arm 34.
FIG. 2 illustrates the relationship of the recirculation flap 54 and the brush 30 in a position in which the brush is new and it is at its full unused diameter. As the brush is worn, it will be periodically rotated about pivot point 36 so that it maintains a proper relationship to the surface being swept. FIG. 3 illustrates the brush in such a moved position. As the brush is pivoted about point 36 by movement of control lever 20, the arm 74, which is attached to the brush support arm 34, will also rotate in a counterclockwise direction. Movement of arm 74 will cause lever 68 to rotate in a clockwise direction, with the difference in position of this lever being shown by a comparison of FIGS. 2 and 3. As lever 68 moves in a clockwise direction, a lower portion thereof, indicated at 78, will cause counterclockwise movement of the arm 64 of rod 62. This in turn will pivot the recirculation flap in a counterclockwise direction so that it will maintain its proper orientation relative to the outer circumference of the brush 30. The difference in flap positions between FIGS. 2 and 3, and the difference in brush positions in the same two figures, illustrates the related movement of the brush and the recirculation flap brought about by the combination of arm 74 attached to the brush support arm 34, the pivotal lever 68, and the rod 64 which is attached to the recirculation flap 54.
It is inherent in over-the-top sweepers that the front wall of the brush housing and the sweeping lip must conform quite closely to the brush to enable the brush to efficiently raise debris. The sweeping lip must be flexible to admit debris under it, and it must drag on the floor to prevent the brush from throwing debris forward. However, because it must remain close to the brush, the lip cannot be lifted very high, or large debris passing under it and lifting it up would lift the lip into the brush, which would then whip it up and hold it off the floor. This would block the passageway for debris up and over the brush and create an opening at floor level through which all debris would be thrown forward.
The present invention provides an operator usable foot pedal which lifts the front flap or sweeping lip to two distinct raised positions, a first position in which the front flap is raised approximately 1" above the surface being swept, with further depression of the pedal swinging the flap assembly forward and up to provide a larger opening.
The foot pedal 22 includes a bushing 24 by which it is pivotally mounted between brackets 80 on the underside of floor 82 of the chassis 10. One end of the foot pedal 22 has a foot portion 84 which is accessible to the operator, as is clearly shown in FIG. 1. The opposite or rear end of pedal 22 is pivotally mounted to a link 86. The lower end of link 86 is pivotally mounted to an arm 88 of a front flap bracket 90 which forms a part of a flap assembly indicated generally at 92 and shown in exploded perspective form in FIG. 4.
The front flap assembly 92 includes a front skirt bracket 94 having arms 96 at the ends thereof. The arms 96 are each pivotally attached, as at 97, to downwardly extending brackets 99 which extend from the underneath side of the floor 82 of the chassis 10. Each of the brackets 99 carries a pin 98 which will ride within a hole 100 in the arms 96, with the pins providing a stop to limit movement of the flap assembly 92.
The assembly 92 includes a retainer 102 and a skirt 104 which has a downwardly extending flexible flap 106 which functions as the so-called lip of the front flap. The skirt 104 in turn will be attached to the front flap bracket 90 with fasteners 101. A spring 110 is connected at its opposite ends to the front flap bracket 90 and the front skirt bracket 94, as depicted in FIG. 4. The front flap bracket 90 is pivotally mounted to the front skirt bracket 94 by means of pins 112 which pass through an opening 114 in the skirt bracket 94 and an opening 116 in the front flap bracket 90.
The various positions of the front flap assembly and the foot pedal are illustrated in FIGS. 2, 5 and 6. FIG. 2 illustrates the conventional and normal position of the front flap. It is located in front of the brush, with the flexible flap portion 106 being bent in a rearward direction so as in no way to impede debris from passing beneath the flap and into the zone of the brush 30. Small objects such as sand, pebbles and the like will easily pass under the flap and then be moved by the brush into the debris hopper. Larger items such as beverage cans will not pass under the front flap and may accumulate in front of it. It is to insure that this type of debris will be thrown into the debris hopper that the front flap assembly is movable.
The first movement by the operator is illustrated in FIG. 5. The pedal 84 has been depressed at its front end with the rear end rising. As the rear end rises, link 86 moves upwardly, which will pull the front flap bracket 90 and its attached skirt 104 in an upward direction, with a slight amount of counterclockwise rotation, as shown in FIG. 5. This movement will normally raise the front flap approximately 1", although that is merely illustrative. Note the different positions of the stop 98 within the opening 100 in FIG. 2 and in FIG. 5. The front flap bracket 90 and skirt 104 will pivot relative to the front skirt bracket 94, as these two portions of the flap assembly are relatively movable.
Further depression of the foot pedal 22, as illustrated in FIG. 6, will raise the link 86 to an even higher position which will rotate the front flap bracket and the attached skirt in a counterclockwise direction which both rotates the flap 106 and raises it. This will permit larger debris such as golf balls, beverage cans, etc., to pass beneath the flap and into the area adjacent the brush for movement by the brush into the debris hopper.
The above-described movement of the front flap is reversed when the operator releases the pedal. First, the front flap will return to the FIG. 5 position where it is approximately vertical and is approximately 1" off the floor. A further and final release of the foot pedal will lower it down to the FIG. 2 position and when the flap is so lowered to its normal position, the flexible portion is vertical when it strikes the floor and the forward motion of the machine naturally bends it back, as there is nothing to cause it to bend forward. Thus, the flap will be in its preferred and normal position and will again permit small debris to pass under it, but in no way will it hinder the movement of the brush in normal operation.
Whereas the preferred form of the invention has been shown and described herein, it should be realized that there may be many modifications, substitutions and alterations thereto. | A sweeping machine has a chassis, wheels for supporting the chassis and a brush mounted on the chassis for rotation to throw debris over the brush and into a debris hopper mounted on the chassis behind the brush. There is a control lever on the chassis for raising and lowering the brush relative to a surface to be swept. As the brush wears, a recirculation flap is positioned between the brush and the debris hopper and located closely adjacent a rear portion of the brush to direct debris not reaching the debris hopper forwardly toward the brush sweeping zone. The recirculation flap is moved toward and away from the brush concurrently with movement of the brush toward the surface being swept as the brush wears, whereby the space between the rear portion of the brush and the recirculation flap remains relatively constant. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates a method of reducing levels of TNFα in a mammal and to compounds and compositions useful therein.
TNFα, or tumor necrosis factor α, is a cytokine which is released primarily by mononuclear phagocytes in response to various immunostimulators. When administered to animals or humans it causes inflammation, fever, cardiovascular effects, hemorrhage, coagulation and acute phase responses similar to those seen during acute infections and shock states.
Excessive or unregulated TNFα production has been implicated in a number of disease conditions. These include endotoxemia and/or toxic shock syndrome {Tracey et al., Nature 330, 662-664 (1987) and Hinshaw et al., Circ. Shock 30, 279-292 (1990)}; cachexia {Dezube et al., Lancet, 335(8690), 662 (1990)}; and Adult Respiratory Distress Syndrome where TNFα concentration in excess of 12,000 pg/milliliters have been detected in pulmonary aspirates from ARDS patients {Millar et al., Lancet 2(8665), 712-714 (1989)}. Systemic infusion of recombinant TNFα also resulted in changes typically seen in ARDS {Ferrai-Baliviera et al., Arch. Surg. 124(12), 1400-1405 (1989)}.
TNFα appears to be involved in bone resorption diseases, including arthritis where it has been determined that when activated, leukocytes will produce a bone-resorbing activity, and data suggest that TNFα contributes to this activity. {Bertolini et al., Nature 319, 516-518 (1986) and Johnson et al., Endocrinology 124(3), 1424-1427 (1989).} It has been determined that TNFα stimulates bone resorption and inhibits bone formation in vitro and in vivo through stimulation of osteoclast formation and activation combined with inhibition of osteoblast function. Although TNFα may be involved in many bone resorption diseases, including arthritis, the most compelling link with disease is the association between production of TNFα by tumor or host tissues and malignancy associated hypercalcemia {Calci. Tissue Int. (U.S.) 46(Suppl.), S3-10 (1990)}. In Graft versus Host Reaction, increased serum TNFα levels have been associated with major complication following acute allogenic bone marrow transplants {Holler et al., Blood, 75(4), 1011-1016 (1990)}.
Cerebral malaria is a lethal hyperacute neurological syndrome associated with high blood levels of TNFα and the most severe complication occurring in malaria patients. Levels of serum TNFα correlated directly with the severity of disease and the prognosis in patients with acute malaria attacks {Grau et al., N. Engl. J. Med. 320(24), 1586-1591 (1989)}.
TNFα also plays a role in the area of chronic pulmonary inflammatory diseases. The deposition of silica particles leads to silicosis, a disease of progressive respiratory failure caused by a fibrotic reaction. Antibody to TNFα completely blocked the silica-induced lung fibrosis in mice {Pignet et al., Nature, 344:245-247 (1990)}. High levels of TNFα production (in the serum and in isolated macrophages) have been demonstrated in animal models of silica and asbestos induced fibrosis {Bissonnette et al., Inflammation 13(3), 329-339 (1989)}. Alveolar macrophages from pulmonary sarcoidosis patients have also been found to spontaneously release massive quantities of TNFα as compared with macrophages from normal donors {Baughman et al., J. Lab. Clin. Med. 115(1), 36-42 (1990)}.
TNFα is also implicated in the inflammatory response which follows reperfusion, called reperfusion injury, and is a major cause of tissue damage after loss of blood flow {Vedder et al., PNAS 87, 2643-2646 (1990)}. TNFα also alters the properties of endothelial cells and has various pro-coagulant activities, such as producing an increase in tissue factor pro-coagulant activity and suppression of the anticoagulant protein C pathway as well as down-regulating the expression of thrombomodulin {Sherry et al., J. Cell Biol. 107, 1269-1277 (1988)}. TNFα has pro-inflammatory activities which together with its early production (during the initial stage of an inflammatory event) make it a likely mediator of tissue injury in several important disorders including but not limited to, myocardial infarction, stroke and circulatory shock. Of specific importance may be TNFα-induced expression of adhesion molecules, such as intercellular adhesion molecule (ICAM) or endothelial leukocyte adhesion molecule (ELAM) on endothelial cells {Munro et al., Am. J. Path. 135(1), 121-132 (1989)}.
Moreover, it now is known that TNFα is a potent activator of retrovirus replication including activation of HIV-1. {Duh et al., Proc. Nat. Acad. Sci. 86, 5974-5978 (1989); Poll et al., Proc. Nat. Acad Sci. 87, 782-785 (1990); Monto et al., Blood 79, 2670 (1990); Clouse et al., J. Immunol. 142, 431-438 (1989); Poll et al., AIDS Res. Hum. Retrovirus, 191-197 (1992)}. AIDS results from the infection of T lymphocytes with Human Immunodeficiency Virus (HIV). At least three types or strains of HIV have been identified, i.e., HIV-1, HIV-2 and HIV-3. As a consequence of HIV infection, T-cell mediated immunity is impaired and infected individuals manifest severe opportunistic infections and/or unusual neoplasms. HIV entry into the T lymphocyte requires T lymphocyte activation. Other viruses, such as HIV-1, HIV-2 infect T lymphocytes after T cell activation and such virus protein expression and/or replication is mediated or maintained by such T cell activation. Once an activated T lymphocyte is infected with HIV, the T lymphocyte must continue to be maintained in an activated state to permit HIV gene expression and/or HIV replication. Cytokines, specifically TNFα, are implicated in activated T-cell mediated HIV protein expression and/or virus replication by playing a role in maintaining T lymphocyte activation. Therefore, interference with cytokine activity such as by prevention or inhibition of cytokine production, notably TNFα, in an HIV-infected individual aids in limiting the maintenance of T lymphocyte caused by HIV infection.
Monocytes, macrophages, and related cells, such as kupffer and glial cells, have also been implicated in maintenance of the HIV infection. These cells, like T cells, are targets for viral replication and the level of viral replication is dependent upon the activation state of the cells. {Rosenberg et al., The Immunopathogenesis of HIV Infection, Advances in Immunology, 57 (1989)}. Cytokines, such as TNFα, have been shown to activate HIV replication in monocytes and/or macrophages {Poli et al. Proc. Natl. Acad. Sci., 87, 782-784 (1990)}, therefore, prevention or inhibition of cytokine production or activity aids in limiting HIV progression as stated above for T cells. Additional studies have identified TNFα as a common factor in the activation of HIV in vitro and has provided a clear mechanism of action via a nuclear regulatory protein found in the cytoplasm of cells (Osborn, et al., PNAS 86, 2336-2340). This evidence suggests that a reduction of TNFα synthesis may have an antiviral effect in HIV infections, by reducing the transcription and thus virus production.
AIDS viral replication of latent HIV in T cell and macrophage lines can be induced by TNFα {Folks et al., PNAS 86, 2365-2368 (1989)}. A molecular mechanism for the virus inducing activity is suggested by TNFα's ability to activate a gene regulatory protein (NFκB) found in the cytoplasm of cells, which promotes HIV replication through binding to a viral regulatory gene sequence (LTR) {Osborn et al., PNAS 86, 2336-2340 (1989)}. TNFα in AIDS associated cachexia is suggested by elevated serum TNFα and high levels of spontaneous TNFα production in peripheral blood monocytes from patients {Wright et al. J. Immunol. 141(1), 99-104 (1988)}.
TNFα has been implicated in various roles with other viral infections, such as the cytomegalia virus (CMV), influenza virus, adenovirus, and the herpes family of viruses for similar reasons as those noted.
Preventing or inhibiting the production or action of TNFα is, therefore, predicted to be a potent therapeutic strategy for many inflammatory, infectious, immunological or malignant diseases. These include but are not restricted to septic shock, sepsis, endotoxic shock, hemodynamic shock and sepsis syndrome, post ischemic reperfusion injury, malaria, mycobacterial infection, meningitis, psoriasis, congestive heart failure, fibrotic disease, cachexia, graft rejection, cancer, autoimmune disease, opportunistic infections in AIDS, rheumatoid arthritis, rheumatoid spondylitis, osteoarthritis, other arthritic conditions, Crohn's disease, ulcerative colitis, multiple sclerosis, systemic lupus erythrematosis, ENL in leprosy, radiation damage, and hyperoxic alveolar injury. Efforts directed to the suppression of the effects of TNFα have ranged from the utilization of steroids such as dexamethasone and prednisolone to the use of both polyclonal and monoclonal antibodies {Beutler et al., Science 234, 470-474 (1985); WO 92/11383}.
The nuclear factor κB (NFκB) is a pleiotropic transcriptional activator (Lenardo, et al. Cell 1989, 58, 227-29). NFκB has been implicated as a transcriptional activator in a variety of disease and inflammatory states and is thought to regulate cytokine levels including but not limited to TNFα and also to be an activator of HIV transcription (Dbaibo, et al. J. Biol. Chem. 1993, 17762-66; Duh et al. Proc. Natl. Acad. Sci. 1989, 86, 5974-78; Bachelerie et al. Nature 1991, 350, 709-12; Boswas et al. J.. Acquired Immune Deficiency Syndrome 1993, 6, 778-786; Suzuki et al. Biochem. And Biophys. Res. Comm. 1993, 193, 277-83; Suzuki et al. Biochem. And Biophys. Res Comm. 1992, 189, 1709-15; Suzuki et al. Biochem. Mol. Bio. Int. 1993, 31(4), 693-700; Shakhov et al. 1990, 171, 35-47; and Staal et al. Proc. Natl. Acad. Sci. U.S.A. 1990, 87, 9943-47). Thus, inhibition of NFκB binding can regulate transcription of cytokine gene(s) and through this modulation and other mechanisms be useful in the inhibition of a multitude of disease states. The compounds claimed in this patent can inhibit the action of NFκB in the nucleus and thus are useful in the treatment of a variety of diseases including but not limited to rheumatoid arthritis, rheumatoid spondylitis, osteoarthritis, other arthritic conditions, septic shock, septis, endotoxic shock, graft versus host disease, wasting, Crohn's disease, ulcerative colitis, multiple sclerosis, systemic lupus erythrematosis, ENL in leprosy, HIV, AIDS, and opportunistic infections in AIDS.
TNFα and NFκB levels are influenced by a reciprocal feedback loop. As noted above, the compounds of the present invention affect the levels of both TNFα and NFκB. It is not known at this time, however, how the compounds of the present invention regulate the levels of TNFα, NFκB, or both.
DETAILED DESCRIPTION
The present invention is based on the discovery that a class of non-polypeptide imides more fully described herein appear to inhibit the action of TNFα.
The present invention pertains to compounds of the formula: ##STR1## in which R 2 is (i) straight, branched, or cyclic, unsubstituted alkyl of 1 to 12 carbon atoms; (ii) straight, branched, or cyclic, substituted alkyl of 1 to 12 carbon atoms; (iii) phenyl; (iv) phenyl substituted with one or more substituents each selected independently of the other from the group consisting of nitro, cyano, trifluoromethyl, carbethoxy, carbomethoxy, carbopropoxy, acetyl, carbamoyl, acetoxy, carboxy, hydroxy, amino, substituted amino, alkyl of 1 to 10 carbon atoms, alkoxy of 1 to 10 carbon atoms, or halo; (v) heterocycle; or (vi) heterocycle substituted with one or more substituents each selected independently of the other from nitro, cyano, trifluoromethyl, carbethoxy, carbomethoxy, carboproxy, acetyl, carbamoyl, acetoxy, carboxy, hydroxy, amino, alkyl of 1 to 10 carbon atoms, alkoxy of 1 to 10 carbon atoms, or halo;
R is --H, alkyl of 1 to 10 carbon atoms, CH 2 OH, CH 2 CH 2 OH, or CH 2 COZ where Z is alkoxy of 1 to 10 carbon atoms, benzyloxy, or NHR 1
where R 1 is H or alkyl of 1 to 10 carbon atoms; and,
Y is i) a phenyl or heterocyclic ring, unsubstituted or substituted one or more substituents each selected independently one from the other from nitro, cyano, trifluoromethyl, carbethoxy, carbomethoxy, carbopropoxy, acetyl, carbamoyl, acetoxy, carboxy, hydroxy, amino, alkyl of 1 to 10 carbon atoms, alkoxy of 1 to 10 carbon atoms, or halo or ii) naphthyl.
A first preferred subclass pertains to compounds in which R 2 is phenyl substituted with two methoxy groups;
R is CH 2 CO 2 CH 3 ; and
Y is a phenyl ring, unsubstituted or substituted with one amino group.
Δ3-(N-benzoylamino)-3-(3,4-dimethoxyphenyl)propionamide,
3-(N-benzoylamino)-3-(3,4-diethoxyphenyl)propionamide,
3-(N-benzoylamino)-3-(3,4-diethylphenyl)propionamide,
3-(N-benzoylamino)-3-cyclohexylpropionamide,
3- N-(3-aminobenzoyl)amino!-3-(3,4-diethoxyphenyl)propionamide,
3- N-(3-methoxybenzoyl)amino!-3-(3,4-diethoxyphenyl)propionamide,
3- N-(4-methoxybenzoyl)amino!-3-(3,4-diethoxyphenyl)propionamide,
methyl 3-(N-benzoylamino)-3-(3,4-diethoxyphenyl)propionate,
methyl 3- N-(3-aminobenzoyl)amino!-3-(3,4-diethoxyphenyl)propionate,
methyl 3- N-(3-methoxybenzoyl)amino!-3-(3,4-diethoxyphenyl)propionate,
methyl 3- N-(4-methoxybenzoyl)amino!-3-(3,4-diethoxyphenyl)propionate,
methyl 3-(N-benzoylamino)-3-(4-trifluoromethylphenyl)propionate,
methyl 3-(N-benzoylamino)-3-(4-acetylphenyl)propionate.
The term alkyl as used herein denotes a univalent saturated branched or straight hydrocarbon chain. Unless otherwise stated, such chains can contain from 1 to 18 carbon atoms. Representative of such alkyl groups are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, isohexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, and the like. When qualified by "lower", the alkyl group will contain from 1 to 6 carbon atoms. The same carbon content applies to the parent term "alkane" and to derivative terms such as "alkoxy".
The compounds can be used, under the supervision of qualified professionals, to inhibit the undesirable effects of TNFα. The compounds can be administered orally, rectally, or parenterally, alone or in combination with other therapeutic agents including antibiotics, steroids, etc., to a mammal in need of treatment. Oral dosage forms include tablets, capsules, dragees, and similar shaped, compressed pharmaceutical forms. Isotonic saline solutions containing 20-100 milligrams/milliliter can be used for parenteral administration which includes intramuscular, intrathecal, intravenous and intra-arterial routes of administration. Rectal administration can be effected through the use of suppositories formulated from conventional carriers such as cocoa butter.
Dosage regimens must be titrated to the particular indication, the age, weight, and general physical condition of the patient, and the response desired but generally doses will be from about 1 to about 500 milligrams/day as needed in single or multiple daily administration. In general, an initial treatment regimen can be copied from that known to be effective in interfering with TNFα activity for other TNFα mediated disease states by the compounds of the present invention. Treated individuals will be regularly checked for T cell numbers and T4/T8 ratios and/or measures of viremia such as levels of reverse transcriptase or viral proteins, and/or for progression of cytokine-mediated disease associated problems such as cachexia or muscle degeneration. If no effect is soon following the normal treatment regimen, then the amount of cytokine activity interfering agent administered is increased, e.g., by fifty percent a week.
The compounds of the present invention also can be used topically in the treatment or prophylaxis of topical disease states mediated or exacerbated by excessive TNFα production, respectively, such as viral infections, such as those caused by the herpes viruses, or viral conjunctivitis, etc.
The compounds also can be used in the veterinary treatment of mammals other than humans in need of prevention or inhibition of TNFα production. TNFα mediated diseases for treatment, therapeutically or prophylactically, in animals include disease states such as those noted above, but in particular viral infections. Examples include feline immunodeficiency virus, equine infectious anaemia virus, caprine arthritis virus, visna virus, and maedi virus, as well as other lentiviruses.
Certain of these compounds possess centers of chirality and can exist as optical isomers. Both the racemates of these isomers and the individual isomers themselves, as well as diastereoisomers when there are two chiral centers, are within the scope of the present invention. The racemates can be used as such or can be separated into their individual isomers mechanically as by chromatography using a chiral absorbent. Alternatively, the individual isomers can be prepared in chiral form or separated chemically from a mixture by forming salts with a chiral acid, such as the individual enantiomers of 10-camphorsulfonic acid, camphoric acid, alpha-bromocamphoric acid, methoxyacetic acid, tartaric acid, diacetyltartaric acid, malic acid, pyrrolidone-5-carboxylic acid, and the like, and then freeing one or both of the resolved bases, optionally repeating the process, so as obtain either or both substantially free of the other; i.e., in a form having an optical purity of >95%.
Prevention or inhibition of production of TNFα by these compounds can be conveniently assayed using anti-TNFα antibodies. For example, plates (Nunc Immunoplates, Roskilde, DK) are treated with 5 μg/milliliter of purified rabbit anti-TNFα antibodies at 4° C. for 12 to 14 hours. The plates then are blocked for 2 hours at 25° C. with PBS/0.05% Tween containing 5 milligrams/milliliter BSA. After washing, 100 μL of unknowns as well as controls are applied and the plates incubated at 4° C. for 12 to 14 hours. The plates are washed and assayed with a conjugate of peroxidase (horseradish) and mouse anti-TNFα monoclonal antibodies, and the color developed with o-phenylenediamine in phosphate-citrate buffer containing 0.012% hydrogen peroxide and read at 492 nm.
The compounds can be prepared using methods which are known in general for the preparation of imides. General reaction schemes include the reaction of the substituted amine or ammonium with substituted benzoyl chloride as illustrated by the formulas: ##STR2##
The following examples will serve to further typify the nature of this invention but should not be construed as a limitation in the scope thereof, which scope is defined solely by the appended claims.
EXAMPLE 1
Methyl N-benzoyl-3-amino-3-(3,4-dimethoxyphenyl)propionate. To an ice bath cooled stirred suspension of methyl 3-amino-3-(3,4-dimethoxyphenyl)propionate hydrochloride (0.689 grams, 2.50 mmol) and triethylamine (0.7 milliliters, 5 mmol) in 15 milliliters of tetrahydrofuran was added 0.3 milliliters of benzoyl chloride (2.6 mmol). The cooling bath was removed after 15 minutes and the mixture stirred for an additional 45 minutes. The reaction mixture was then diluted with 15 milliliters of brine and 15 milliliters of water and then partially concentrated in vacuo to remove the tetrahydrofuran. The reaction slurry was filtered, the solid air-dried, then dried in vacuo (60° C., <1 mm) to afford 0.86 g (100%) of the product as a white powder: 1 H NMR (dmso-d 6 , 250 MHz) δ 8.84 (d, J=8.3 Hz, 1 H, NH), 7.83 (m, 2 H, Ar), 7.60-7.35 (m, 3 H, Ar), 7.06 (s, 1 H, Ar), 6.90 (m, 2 H, Ar), 5.50-5.30 (m, 1 H, CHN), 3.75 (s, 3 H, OCH 3 ), 3.72 (s, 3 H, OCH 3 ), 3.46 (s, 3 H, CO 2 CH 3 ), 3.05-2.75 (m, 2 H, CH 2 ); 13 C NMR (dmso-d 6 ) δ 170.8, 165.6, 148.6, 147.9, 134.9, 134.5, 131.2, 128.3, 127.3, 118.5, 111.6, 110.6, 55.5, 55.5, 51.4, 49.7, 40.6. Anal. Calcd for C 19 H 21 NO 5 . Theoretical C, 66.46; H, 6.16; N, 4.08. Found C, 66.22; H, 6.05; N, 3.98.
EXAMPLE 2
Methyl N-(3-nitrobenzoyl)-3-amino-3-(3,4-dimethoxyphenyl)propionate. To an ice bath cooled stirred suspension of methyl 3-amino-3-(3,4-dimethoxyphenyl)propionate hydrochloride (1.38 grams, 5.00 mmol) and triethylamine (1.5 milliliters, 10.8 mmol) in 10 milliliters of tetrahydrofuran was added 3-nitrobenzoyl chloride (0.928 grams, 5.00 mmol) in a single portion. A thick slurry resulted. The cooling bath was removed after 15 minutes, the mixture diluted with 10 milliliters of tetrahydrofuran and the mixture stirred for an additional hour. The reaction mixture was diluted with 50 milliliters of water and then partially concentrated in vacuo to remove the tetrahydrofuran. The reaction slurry was filtered, the solid washed with copious amounts of water, air-dried, and dried in vacuo (60° C., <1 mm) to afford 1.85 grams (95%) of the product as an off white powder: 1 H NMR (CDCl 3 , 250 MHz) δ 8.63 (t, J=1.9 Hz, 1 H), 8.35 (m, 1 H, Ar), 8.20 (m, 1 H, Ar), 7.77 (d, J=8 Hz, 1 H, NH), 7.63 (t, J=8.0 Hz, 1 H), 6.95-6.75 (m, 3 H, Ar), 5.86 (m, 1 H, CHCO), 3.85 (s, 3 H, OCH 3 ), 3.84 (s, 3 H, OCH 3 ), 3.68, (s, 3 H, CO 2 CH 3 ), 3.01 (m, 2 H, CH 2 ); 13 C NMR (CDCl 3 ) δ 172.0, 164.1, 149.1, 148.6, 148.2, 135.8, 133.1, 132.7, 129.8, 126.1, 122.0, 118.2, 111.2, 109.9, 55.9, 55.8, 52.0, 50.2, 39.5.
EXAMPLE 3
Methyl N-(3-aminobenzoyl)-3-amino-3-(3,4-dimethoxyphenyl)propionate. To a solution of methyl N-(3-nitrobenzoyl)-3-amino-3-(3,4-dimethoxyphenyl)propionate (1.25 grams, 3.22 mmol) in a mixture of 150 milliliters of ethyl acetate and 75 milliliters of methanol (mixture gently warmed to dissolve all solid and then allowed to cool to room temperature) was added 0.25 grams of 10% Pd/C. The mixture was then treated with 60 psi of H 2 for 2.5 hours on a Parr Type Shaker. Reaction progress was monitored by TLC (1/9 ethyl acetate/methylene chloride, UV) and was complete after 2.5 hours. The reaction mixture was filtered through celite to remove catalyst. The filtrate was concentrated in vacuo to afford a white solid which was dried in vacuo (60° C., <1 mm) to afford 1.07 grams (93%) of the desired product: 1 H NMR (dmso-d 6 , 250 MHz) δ 8.60 (d, J=8.5 Hz, 1 H, NH), 7.15-6.8 (m, 6 H, Ar), 6.67 (m, 1 H, Ar), 5.40 (m, 1 H, CHCO), 5.24 (m 2 H, ArNH 2 ), 3.75 (s, 3 H, OCH 3 ), 3.72 (s, 3 H, OCH 3 ), 3.56 (s, 3 H, CO 2 CH 3 ), 2.95 (dd, J=8.9, 15.4 Hz, 1 H), 2.81 (dd, J=6.3, 15.4 Hz, 1 H); 13 C NMR (dmso-d 6 ) δ 170.9, 166.4, 148.6, 148.6, 147.8, 135.6, 135.1, 128.6, 118.5, 116.4, 114.4, 112.8, 111.6, 110.6, 55.5, 55.5, 51.4, 49.6, 40.7.
EXAMPLE 4
Methyl N-(4-nitrobenzoyl)-3-amino-3-(3,4-dimethoxyphenyl)propionate. To an ice bath cooled stirred suspension of methyl 3-amino-3-(3,4-dimethoxyphenyl)propionate hydrochloride(1.38 grams, 5.00 mmol) and triethylamine (1.5 milliliters, 10.8 mmol) in 25 milliliters of tetrahydrofuran was added 4-nitrobenzoyl chloride (0.928 grams, 5.00 mmol) in a single portion. After 15 minutes, the cooling bath was removed and the reaction mixture stirred for 45 minutes. The reaction mixture was then diluted with 50 milliliters of water. The reaction slurry was filtered and the solid washed with water, air-dried, and then dried in vacuo (60 C, <1 mm) to afford 1.86 grams (94%) of the product as a yellow powder: 1 H NMR (CDCl 3 /TMS, 250 MHz) δ 8.27 (d, J=8.8 Hz, 2 H), 7.98 (d, J=8.8 Hz, 2 H), 7.77 (d, J=8.1 Hz, 1 H, NH), 6.95-6.75 (m, 3 H, Ar), 5.55 (m, 1 H, CH), 3.86 & 3.85 (2 s, 6 H, 2 OCH 3 ), 3.68 (s, 3 H, CO 2 CH 3 ), 3.00 (m, 2 H, CH 2 ); 13 C NMR (CDCl 3 /TMS) δ 172.2, 164.4, 149.6, 1491, 148.7, 139.7, 132.6, 128.2, 123.8, 118.1, 111.2, 109.9, 55.9, 55.8, 52.0, 50.0, 39.3.
EXAMPLE 5
Methyl N-(4-aminobenzoyl)-3-amino-3-(3,4-dimethoxyphenyl)propionate. To a solution of methyl N-(3-nitrobenzoyl)-3-amino-3-(3,4-dimethoxyphenyl)propionate (1.25 grams, 3.22 mmol) in a mixture of 100 milliliters of ethyl acetate and 50 milliliters of methanol (mixture gently warmed to dissolve all solid and then allowed to cool to room temperature) was added 0.25 grams of 10% Pd/C. The mixture was then treated with 60 psi of H 2 for 2.5 hours on a Parr Type Shaker. Reaction progress was monitored by TLC (1/9 ethyl acetate/methylene chloride, UV) and was complete after 2.5 hours. The reaction mixture was filtered through celite to remove catalyst. The filtrate was concentrated in vacuo to afford a white solid which was dried in vacuo (60° C., <1 mm) to afford 1.10 grams (96%) of the desired product: 1 H NMR (dmso-d 6 , 250 MHz) δ 8.32 (d, J=8.5 Hz, 1 H, NH), 7.57 (d, J=8.6 Hz, 1 H, Ar), 7.03 (s, 1 H, Ar), 6.88 (m, 2 H, Ar), 6.54 (d, J=8.6, 2 H, Ar), 5.62 (s, 2 H, NH 2 ), 5.38 (m, 1 H, CHCO 2 ), 3.74 (s, 3 H, OCH 3 ), 3.71 (s, 3 H, OCH 3 ), 3.56 (s, 3 H, CO 2 CH 3 ), 2.94 (dd, J=8.8, 15.3 H), 2.80 (dd, J=6.5, 15.3, 1 H); 13 C NMR (dmso-d 6 ) δ 170.9, 165.5, 151.7, 148.5, 147.8, 135.4, 128.8, 121.1, 118.5, 112.5, 111.6, 110.6, 55.5, 55.5, 51.3, 49.4, 40.8.
EXAMPLE 6
Methyl N-(3-methoxybenzoyl)-3-amino-3-(3',4'-dimethoxyphenyl)propionate. To an ice bath stirred suspension of methyl 3-amino-3-(3',4'-dimethoxyphenyl)propionate hydrochloride (0.689 grams, 2.50 mmol) and 0.7 milliliters of triethylamine in 20 milliliters of anhydrous tetrahydrofuran was added 3-methoxybenzoyl chloride (2.5 mmol) via syringe. After 30 minutes, the reaction mixture was allowed to warm to room temperature and stirred for 1 hour. The reaction mixture was then treated with 20 milliliters of water. The tetrahydrofuran was removed in vacuo and the resulting mixture extracted with methylene chloride (2 times with 25 milliliters). The combined extracts were dried over sodium sulfate and contracted to afford a thick oil. The crude product was purified by flash chromatography (silica gel, 1.4/8.6 ethyl acetate/hexanes) to afford 0.5 grams (56%) as a pale green solid (wax): mp 123.5°-125° C.; 1 H NMR (CDCl 3 /TMS) δ 8.96 (d, J=7.9, 1 H), 8.19 (m, 1 H), 7.45 (m, 1 H), 7.12-6.68 (m, 5 H), 5.59 (m, 1 H), 4.00 (s, 3 H, OCH 3 ), 3.87 (s, 3 H, OCH 3 ), 3.85 (s, 3 H, OCH 3 ), 3.63 (s, 3 H, OCH 3 ), 2.96 (m, 2 H, CH 2 ); 13 C NMR (CDCl 3 /TMS) δ 171.6, 164.4, 157.6, 148.9, 148.2, 133.8, 132.8, 132.3, 121.3, 121.2, 118.1, 111.3, 111.2, 109.9. 55.8, 55.8, 51.6, 49.7, 40.4; TLC (2/8 ehtyl acetate/hexanes, UV) R f =0.26. Anal. Calcd for C 20 H 23 NO 6 . Theory C, 64.33; H, 6.21; N, 3.75. Found C, 64.31; H, 6.25; N, 3.63.
EXAMPLE 7
Methyl N-nicotinoyl-3-amino-3-(3',4'-dimethoxyphenyl)propionate. To a cooled (0° C.) stirred suspension of 3-amino-3-(3',4'-dimethoxyphenyl)propionate hydrochloride (1.38 grams, 5.0 mmol) and triethylamine (1.5 milliliters, 10.8 mmol) in 20 milliliters of tetrahydrofuran was added nicotinoyl chloride hydrochloride (0.89 grams, 5.0 mmol). The thick slurry was stirred for 15 minutes and then allowed to warm to room temperature and stirring was continued for 2 hours. The reaction mixture was treated with 20 milliliters of water resulting in a brown colored solution. The tetrahydrofuran was removed in vacuo and the aqueous layer was extracted with methylene chloride (3 times, 25 milliliters). The combined extracts were dried over magnesium sulfate and concentrated in vacuo to afford an oil which solidified overnight. The white solid was dried in vacuo (60° C., <1 mm) to afford 0.52 grams (30%) of crude product. The crude product was purified by flash chromatography (silica gel, 5% methanol/methylene chloride) and dried in vacuo (60° C., <1 mm) to afford 0.38 grams (22%) of the product as a white solid: 1 H NMR (CDCl 3 ) δ 9.10-9.00(m, 1 H), 8.80-8.69(m, 1 H), 8.19-8.08(m, 1 H), 7.65-7.31(m, 2 H), 6.96-6.76(m , 3 H), 5.64-5.50(m, 1 H), 3.87(s, 3 H), 3.67(s, 3 H), 3.14-2.37(m, 2 H). 13 C NMR (CDCl 3 ) δ 172.1, 164.6, 152.4, 149.2, 148.7, 148.1, 135.0, 132.8, 129.9, 123.5, 118.1, 111.3, 111.2, 109.9, 109.8, 55.9, 52.0, 49.8, 39.5. HPLC 99.47%.
EXAMPLE 8
Methyl N-acetyl-3-(3,4dimethoxyphenyl)propionate. To an ice bath cooled stirred suspension of methyl 3-amino-3-(3,4-dimethoxyphenyl)propionate hydrochloride (1.97 grams, 7.14 mmol) and triethylamine (2.15 milliliters, 15.43 mmol) in 30 milliliters of tetrahydrofuran was added acetyl chloride (0.51 milliliters, 7.14 mmol). The cooling bath was removed after 15 minutes and the mixture stirred for an additional 2 hours. The reaction mixture was diluted with water (25 milliliters) and was then partially concentrated in vacuo to remove the tetrahydrofuran. The remaining aqueous mixture was extracted with methylene chloride (3 times, 20 milliliters) and the combined organic extracts were dried over magnesium sulfate. The methylene chloride was removed in vacuo to afford 1.40 grams of crude product as an orange oil. The crude product was purified by flash chromatography (silica gel, 5% methanol/methylene chloride) to afford 1.22 grams of product as an oil which later solidified, some minor impurities persisted and the solid was recrystallized from hexane/ethyl acetate. The white solid was dried in vacuo (60° C., <1 mm) to afford 0.81 grams (41%) of product as a white solid: 1 H NMR (CDCl 3 ) δ 6.92-6.79(m, 3 H), 6.56-6.39(m, 1 H), 5.45-5.03(m, 1 H), 3.87(s, 3H), 3.86(s, 3 H), 3.63(s, 3 H), 3.02-2.75(m, 2 H), 2.02(s, 3 H); 13 C NMR (CDCl 3 ) δ 171.7, 169.2, 149.1, 148.5, 133.1, 118.1, 111.2, 110.0, 55.9, 51.8, 49.4, 39.7, 23.4; HPLC 98.63%.
EXAMPLE 9
Tablets, each containing 50 milligrams of active ingredient, can be prepared in the following manner:
______________________________________Constituents (for 1000 tablets)______________________________________active ingredient 50.0 gramslactose 50.7 gramswheat starch 7.5 gramspolyethylene glycol 6000 5.0 gramstalc 5.0 gramsmagnesium stearate 1.8 gramsdemineralized water q.s.______________________________________
The solid ingredients are first forced through a sieve of 0.6 mm mesh width. The active ingredient, the lactose, the talc, the magnesium stearate and half of the starch then are mixed. The other half of the starch is suspended in 40 milliliters of water and this suspension is added to a boiling solution of the polyethylene glycol in 100 milliliters of water. The resulting paste is added to the pulverulent substances and the mixture is granulated, if necessary with the addition of water. The granulate is dried overnight at 35° C., forced through a sieve of 1.2 mm mesh width and compressed to form tablets of approximately 6 mm diameter which are concave on both sides.
EXAMPLE 10
Tablets, each containing 100 milligrams of active ingredient, can be prepared in the following manner:
______________________________________Constituents (for 1000 tablets)______________________________________active ingredient 100.0 gramslactose 100.0 gramswheat starch 47.0 gramsmagnesium stearate 3.0 grams______________________________________
All the solid ingredients are first forced through a sieve of 0.6 mm mesh width. The active ingredient, the lactose, the magnesium stearate and half of the starch then are mixed. The other half of the starch is suspended in 40 milliliters of water and this suspension is added to 100 milliliters of boiling water. The resulting paste is added to the pulverulent substances and the mixture is granulated, if necessary with the addition of water. The granulate is dried overnight at 35° C., forced through a sieve of 1.2 mm mesh width and compressed to form tablets of approximately 6 mm diameter which are concave on both sides.
EXAMPLE 11
Tablets for chewing, each containing 75 milligrams of active ingredient, can be prepared in the following manner:
______________________________________Composition (for 1000 tablets)______________________________________active ingredient 75.0 gramsmannitol 230.0 gramslactose 150.0 gramstalc 21.0 gramsglycine 12.5 gramsstearic acid 10.0 gramssaccharin 1.5 grams5% gelatin solution q.s.______________________________________
All the solid ingredients are first forced through a sieve of 0.25 mm mesh width. The mannitol and the lactose are mixed, granulated with the addition of gelatin solution, forced through a sieve of 2 mm mesh width, dried at 50° C. and again forced through a sieve of 1.7 mm mesh width. The active ingredient, the glycine and the saccharin are carefully mixed, the mannitol, the lactose granulate, the stearic acid and the talc are added and the whole is mixed thoroughly and compressed to form tablets of approximately 10 mm diameter which are concave on both sides and have a breaking groove on the upper side.
EXAMPLE 12
Tablets, each containing 10 milligrams of active ingredient, can be prepared in the following manner:
______________________________________Composition (for 1000 tablets)______________________________________active ingredient 10.0 gramslactose 328.5 gramscorn starch 17.5 gramspolyethylene glycol 6000 5.0 gramstalc 25.0 gramsmagnesium stearate 4.0 gramsdemineralized water q.s.______________________________________
The solid ingredients are first forced through a sieve of 0.6 mm mesh width. Then the active ingredient, lactose, talc, magnesium stearate and half of the starch are intimately mixed. The other half of the starch is suspended in 65 milliliters of water and this suspension is added to a boiling solution of the polyethylene glycol in 260 milliliters of water. The resulting paste is added to the pulverulent substances, and the whole is mixed and granulated, if necessary with the addition of water. The granulate is dried overnight at 35° C., forced through a sieve of 1.2 mm mesh width and compressed to form tablets of approximately 10 mm diameter which are concave on both sides and have a breaking notch on the upper side.
EXAMPLE 13
Gelatin dry-filled capsules, each containing 100 milligrams of active ingredient, can be prepared in the following manner:
______________________________________Composition (for 1000 capsules)______________________________________active ingredient 100.0 gramsmicrocrystalline cellulose 30.0 gramssodium lauryl sulphate 2.0 gramsmagnesium stearate 8.0 grams______________________________________
The sodium lauryl sulphate is sieved into the active ingredient through a sieve of 0.2 mm mesh width and the two components are intimately mixed for 10 minutes. The microcrystalline cellulose is then added through a sieve of 0.9 mm mesh width and the whole is again intimately mixed for 10 minutes. Finally, the magnesium stearate is added through a sieve of 0.8 mm width and, after mixing for a further 3 minutes, the mixture is introduced in portions of 140 milligrams each into size 0 (elongated) gelatin dry-fill capsules.
EXAMPLE 14
A 0.2% injection or infusion solution can be prepared, for example, in the following manner:
______________________________________active ingredient 5.0 gramssodium chloride 22.5 gramsphosphate buffer pH 7.4 300.0 gramsdemineralized water to 2500.0 milliliters______________________________________
The active ingredient is dissolved in 1000 milliliters of water and filtered through a microfilter. The buffer solution is added and the whole is made up to 2500 milliliters with water. To prepare dosage unit forms, portions of 1.0 or 2.5 milliliters each are introduced into glass ampoules (each containing respectively 2.0 or 5.0 milligrams of active ingredient). | Novel aryl amides are inhibitors of tumor necrosis factor α and can be used to combat cachexia, endotoxic shock, and retrovirus replication. A typical embodiment is N-benzoyl-3-amino-3-(3',4'-dimethoxyphenyl)propanamide. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 10/175,883, filed Jun. 21, 2002, now abandoned which is a continuation of International Application No. PCT/AU00/01592, filed on Dec. 22, 2000, which claims the benefit of priority to Australian Application No. AU-PQ4854, filed Dec. 23, 1999, and Australian Application No. AU-PQ7450, filed May 12, 2000, the contents of each of these applications are hereby incorporated by reference in their entireties for all purposes.
FIELD OF THE INVENTION
The present invention relates to improved pharmaceutical compositions of drugs that are practically insoluble in aqueous media. The present invention also relates to a process for preparing the compositions. Furthermore, the present invention relates to improved dosage forms for the administration of the compositions.
BACKGROUND OF THE INVENTION
Drugs that are totally water-insoluble, or are at least poorly water-soluble, are usually characterised by low absorption and poor bioavailability, and present special difficulties when formulating dosage forms therefor. For the purposes of this specification, such drugs will be referred to as being “practically insoluble”.
Indeed, it has been reported that the bioavailability of many practically insoluble drugs is limited by their dissolution rates and solubility, which in turn are understood to be controlled by the surface area that they present for dissolution. As such, attempts to improve the bioavailability of these practically insoluble drugs have often focussed on particle size reduction.
Examples of attempts to improve the bioavailability of such drugs are illustrated in international patent applications PCT/EP93/02327 and PCT/EP98/01773 both to Janssen Pharmaceutica N.V. These applications both relate to dosage forms of azole antifungals, such as itraconazole and sapereonazole, which are said to be only very sparingly soluble in water, and both describe the incorporation of the drug with water-soluble polymers and the subsequent coating of the mixture on small beads. In PCT/EP93/02327 the beads are 600 to 700 micrometer in diameter, whereas in PCT/EP98/01773 the beads are 250 to 355 micrometer in diameter.
The dosage forms in both applications are said to have good bioavailability in a form suitable for oral administration, and are both designed for dissolution in the stomach.
Janssen adopted a different approach in international patent application PCT/EP97/02507, again for azole antifungals such as itraconazole and saperconazole. In this patent application, the proposed solution to the bioavailability problem is to form a solid dispersion of the practically insoluble drug and a water soluble polymer, with ratios of drug to polymer that aim to dissolve the drug to ensure that the required bioavailability is obtained.
Another approach is reported in the article “Oral Absorption Improvement of Poorly Soluble Drug Using Solid Dispersion Technique” by T. Kai et al (Chem. Pharm. Bull. 44(3) 568-571(1996)) in relation to another antifungal agent, again said to be of low solubility and exhibiting poor oral absorption characteristics. In this article, a solid dispersion of the drug is formed with an enteric polymer and the dissolution characteristics of the solid dispersion are tested in suitable media at pH 1.2 and pH 6.8, with a view to determining the dissolution state of the drug. The article verifies that the drug at pH 6.8 is fully dissolved (supersaturated) and is thus bioavailable, whereas at pH 1.2 the enteric polymers had not dissolved, preventing dissolution of the drug. The article thus promotes as important the supersaturation (complete dissolution) of the drug to ensure adequate bioavailability.
A final attempt to be illustrated is that of European patent application 98305960.1 to Pfizer Products Inc. This application is again aimed at improving the bioavailability of low-solubility drugs such as glycogen phosphorylase inhibitors, 5-lipoxygenase inhibitors, corticotropic releasing hormone inhibitors and antipsychotics.
The Pfizer patent application suggests the use of a solid dispersion of an enteric polymer (namely, hydroxypropylmethylcellulose acetate succinate [HPMCAS]) with the low-solubility drug, again to produce a supersaturated solution in vivo to ensure adequate bioavailability. Indeed, this application specifically aims to produce a supersaturated solution of the drug in order to keep the drug dissolved for as long as possible after administration.
Further in relation to practically insoluble dings, it has been reported that many such drugs are formulated into dosage forms that should only be administered with food. For example, a commercially available itraconazole dosage form (Sporanox™) is only prescribed for use with food because of relatively poor bioavailability results when administered under fasted conditions.
It is an aim of the present invention to provide a pharmaceutical composition with improved bioavailability for drugs that are considered to be practically insoluble.
However, before turning to discuss the invention, it should be appreciated that the above discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia or elsewhere before the priority date of each claim of this application.
SUMMARY OF THE INVENTION
The present invention provides a pharmaceutical composition of a practically insoluble drug, wherein the composition may be administered with food or without food. In this form of the invention, the composition may be in the form of a solid dispersion of the practically insoluble drug and a polymer having acidic functional groups, and the composition may in vitro form a suspension.
The present invention also provides a pharmaceutical composition of a practically insoluble drug, the composition having an AUC under fed conditions that is 80% to 125% of the composition's AUC under fasted conditions. In this form of the invention, the composition may be in the form of a solid dispersion of the practically insoluble drug and a polymer having acidic functional groups, and the composition may in vitro form a suspension.
Further, the present invention provides a pharmaceutical composition of a practically insoluble drug, wherein in vitro the composition forms a suspension. In a preferred form, the composition may be in the form of a solid dispersion of the practically insoluble drug and a polymer having acidic functional groups.
Of course, in all forms of the present invention, and as will be explained below, it will be appreciated that the pharmaceutical composition may include other components within it, such as disintegrants, diluents, fillers and the like.
Various terms that will be used throughout this specification have meanings that will be well understood by a skilled addressee. However, for ease of reference, some of these terms will now be defined.
The term “practically insoluble” as used herein applies to drugs that are essentially totally water-insoluble or are at least poorly water-soluble. More specifically, the term is applied to any drug that has a dose (mg) to aqueous solubility (mg/ml) ratio greater than 100 ml, where the drug solubility is that of the neutral (for example, free base or free acid) form in unbuffered water. This meaning is to include, but is not to be limited to, drugs that have essentially no aqueous solubility (less than 1.0 mg/ml).
The term “drug” will be widely understood and denotes a compound having beneficial prophylactic and/or therapeutic properties when administered to, for example, humans. Further, the term “drug per se” is used throughout this specification for the purposes of comparison, and means the drug when in an aqueous solution/suspension without the addition of any excipients.
The term “a solid dispersion” in general means a system in solid state comprising at least two components, wherein one component is dispersed more or less evenly throughout the other component or components. In particular, and with reference to a widely accepted definition from the early 1970's, “solid dispersions” are the dispersion of one or more active ingredients in an inert carrier or matrix at solid state, prepared by the melting, solvent, or melting-solvent methods.
The term “in vivo” in general means in the living body of a plant or animal, whereas the term “in vitro” generally means outside the body and in an artificial environment.
Reference throughout this specification will be made to the administration of a pharmaceutical composition under fed conditions or fasted conditions. It is well understood in the art that the pharmacokinetic performance of some compositions is affected by the presence or not of food in the gastro-intestinal system. Other compositions are not so affected. These references thus relate to the normally accepted administration circumstances that are referred to in the art as ‘fed’ or ‘fasted’.
Reference will also be made to the pharmacokinetic parameter AUC. This is a widely accepted parameter determined from the graphical presentation of actual or theoretical plasma profiles (concentration vs time), and represents the area under the curve (AUC) of such a profile.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plot of the mean itraconazole plasmas levels.
FIG. 2 is a plot of the mean plasma concentrations of itraconazole containing formulations of the present invention in the fed and fasted state.
GENERAL DESCRIPTION OF THE INVENTION
Returning now to a general description of the present invention, in one form of the invention the pharmaceutical composition is such that, upon administration, a suspension is formed in vivo. Preferably, the suspension is a homogeneous dispersion of particles (containing the drug), the particles at least being of a size where, in vitro, they diffract light such that the suspension presents as a cloudy suspension. Thus, evidence of the presence of such a cloudy suspension can be seen during in vitro dissolution testing of the solid dispersion of the inventive composition.
The particles in the cloudy suspension in vitro will generally be particles of a size greater than about 1 nm but less than about 10 micrometer. In vitro dissolution testing of a pharmaceutical composition according to this form of the present invention reveals that particles in this size range are present when tested at a pH in the range of 5.5 to 7.5. Additionally, when pretreated at acidic pH (namely, when suspended in a dissolution medium at a pH of about 1.2 for a period of about 20 minutes), in vitro dissolution testing of a pharmaceutical composition according to this form of the present invention again reveals that particles in this size range are present when subsequently tested at a pH in the range of 5.5 to 7.5. This pre-treatment may be conducted to simulate in vivo conditions.
In one form of the present invention, it may be preferred for a portion of the particles to be present in nanoparticulate form, such as in the range of 1 nm to 450 nm, and a portion to be present in microparticulate form (such as in the range of 0.45 micrometer to 10 micrometer). The presence of such nanoparticles in vivo may be determined by testing for them in vitro, such as by passing the cloudy suspension through a 450 nm filter and having the suspension remain cloudy. Such nanoparticles are preferably present regardless of whether the acidic pre-treatment step described above is utilised in the testing procedure.
Therefore, the present invention additionally provides a pharmaceutical composition of a practically insoluble drug, wherein the composition forms a suspension in vitro at a pH in the range of 5.5 to 7.5, the suspension having particles in the size range of 1 nm to 10 micrometer, with or without a pre-treatment at acidic pH. Preferably, the suspension has at least a portion of its particles in the size range of 1 nm to 450 nm in vitro at a pH in the range of 5.5 to 7.5, again with or without a pre-treatment at acidic pH.
In this preferred form, the pharmaceutical composition may therefore provide for acceptable absorption of the practically insoluble drug (where acceptable absorption is indicated by the extent of the absorption being greater than that of the crystallised form of the drug per se), in the intestines where the pH is expected to be in the range of 5.5 to 7.5.
In another form of the present invention (as mentioned above), the pharmaceutical composition may be administered with food or without food. This is beneficial as many practically insoluble drugs are unable to be formulated in a manner that allows administration without food, particularly those typically formulated as solid dosage forms. This makes administration of these dosage forms cumbersome; and quite inflexible for the patient. Indeed, the pharmaceutical composition of the present invention is preferably bioequivalent when administered under fed conditions compared to administration under fasted conditions. In particular, the AUC for a composition administered under fed conditions is preferably within the range of 80 to 125% of the AUC under fasted conditions, when considering the 90% confidence interval for the ratio of the fed value to the fasted value (using natural log transformed data).
Any practically insoluble drug may be beneficially used in the pharmaceutical composition of the present invention. In this respect, it should be appreciated that while the specification will here list various drugs that are typically considered to be practically insoluble, many drugs (whether considered practically insoluble or not) will have versions (crystalline forms, polymorphs, etc) that are in fact practically insoluble. Also, it is to be appreciated that drugs developed in the future that are also considered to be practically insoluble, are also to be included within the scope of the present invention.
While the specific benefits of the pharmaceutical composition of the present invention have been established by the inventors for azole antifungal drugs, such as itraconazole and saperconazole, similar benefits will be available for other classes of drugs such as anti-hypertensives, immunosuppressants, anti-inflammatories, diuretics, antiepileptics, cholesterol lowering drugs, hormonals, hypoglycemics, antiviral drugs, nasal decongestants, antimicrobials, anti-arrthrytics, analgesics, anti-cancer drugs, anti-parasitics, proteins, peptides, CNS stimulants, CNS depressants, 5 HT inhibitors, anti-schizophrenics, anti-Alzheimer drugs, anti-psoriatics, steroidals, oligonucleotides, anti-ulcer drugs, proton pump inhibitors, anti-asthmatics, thrombolyitics and vitamins.
Indeed, even though the following description will mainly describe embodiments of the invention with respect to azole antifungal drugs, it is to be appreciated that the invention is not to be so limited.
The polymers useful for forming the solid dispersion of the pharmaceutical composition of the present invention are those having acidic functional groups. In a preferred form, such polymers will be polycarboxylic acids. Such polycarboxylic acids may be any polycarboxylic acid which, when in a solid dispersion with a practically insoluble drug, results in the formation of the abovementioned suspension, ideally in the preferred pH ranges, and preferably to provide acceptable absorption in the intestines.
Such polymers may be one or more of the group comprising hydroxypropyl methylcellulose phthalate, polyvinyl acetate phthalate (PVAP), hydroxypropylmethylcellulose acetate succinate (HPMCAS), alginate, carbomer, carboxymethyl cellulose, methacrylic acid copolymer, shellac, cellulose acetate phthalate (CAP), starch glycolate, polacrylin, methyl cellulose acetate phthalate, hydroxypropylcellulose acetate phthalate, cellulose acetate terephthalate, cellulose acetate isophthalate and cellulose acetate trimellitate, and includes the various grades of each polymer such as HPMCAS-LF, HPMCAS-MF and HPMCAS-HG.
In a particularly preferred form of the present invention, the polymer is a polycarboxylic acid such as a hydroxypropyl methylcellulose phthalate such as that available from Shin-Etsu Chemical Industry Co Ltd as HP-50, HP-55 or HP-55S. However, it is envisaged that alternatives such as the use of an aqueous based enteric polymer, such as the dispersion Eudragit L30D, or enteric polymers dissolved in water with the addition of ammonia or alkaline agents, may be useful.
In relation to amounts of drug and the polymer in the solid dispersion, the ratio of drug to polymer may be in the range of from 3:1 to 1:20. However, ratios in the narrower range of 3:1 to 1:5 are preferred. An even more preferred range is 1:1 to 1:3, with the most preferred ratio being about 1:1.5 (or 2:3).
The solid dispersion of the composition of the present invention is preferably formed by spray drying techniques, although it will be understood that suitable solid dispersions may be formed by a skilled addressee utilising other conventional techniques, such as co-grinding, melt extrusion, freeze drying, rotary evaporation or any solvent removal process.
In the preferred spray drying technique, the solid dispersion is formed by dispersing or dissolving the drug and the polymer in a suitable solvent, and subsequently spray drying to form the solid dispersion in the form of a powder. Suitable solvents or dispersion media include methylene chloride, chloroform, ethanol, methanol, propan-2-ol, ethylacetate, acetone, water or mixtures thereof.
Other excipients may then be blended into the powder (with or without milling or grinding) to form a composition suitable for use in dosage forms such as tablets and capsules.
The present invention therefore also provides a process for preparing a pharmaceutical composition of a practically insoluble drug, the process including dispersing in a solvent the drug and a polymer having acidic functional groups, and spray drying the dispersion to form a solid dispersion.
The present invention may thus provide a process for preparing a pharmaceutical composition of a practically insoluble drug, where the process includes the steps of:
(a) adding a polymer having acidic functional groups to a solvent to form a dispersion; (b) adding the drug to the dispersion to form a suspension or solution; and (c) spray drying the suspension or solution to form the pharmaceutical composition in the form of a solid dispersion.
Alternatively, the present invention may provide a process for preparing a pharmaceutical composition of a practically insoluble drug, where the process includes the steps of:
(a) adding the drug to a solvent to form a dispersion; (b) adding a polymer having acidic functional groups drug to the dispersion to form a suspension or solution; and (c) spray drying the suspension or solution to form the pharmaceutical composition in the form of a solid dispersion.
The composition of the present invention may be formulated into pharmaceutical dosage forms comprising a therapeutically effective amount of the composition. Although pharmaceutical dosage forms for oral administration, such as tablets and capsules, are envisaged, the composition of the present invention can also be used to prepare other pharmaceutical dosage forms, such as for rectal, vaginal, ocular or buccal administration, or the like. It should also be appreciated that the solid dispersions of the composition of the invention may be spray coated (or the like) onto cores to produce particles suitable for use in any of these dosage forms.
It will also be appreciated that various of these dosage forms may include a range of traditional excipients such as disintegrants, diluents, fillers, lubricants, glidants, colourants and flavours.
For example, suitable disintegrants may be those that have a large coefficient of expansion, and examples may include crosslinked polymers such as crospovidone (crosslinked polyvinylpyrrolidone), croscarmellose (crosslinked sodium carboxymethylcellulose), and sodium starch glycolate.
Also, it will be appreciated that it may be advantageous to add to a dosage form an inert substance such as a diluent or a filler. A variety of materials may be used as diluents or fillers, and examples may be sucrose, dextrose, mannitol, sorbitol, starch, micro-crystalline cellulose, and others known in the art, and mixtures thereof.
Lubricants and glidants may be employed in the manufacture of certain dosage forms, and will usually be employed when producing tablets. Examples of lubricants and glidants are hydrogenated vegetable oils, magnesium stearate, stearic acid, sodium lauryl sulfate, magnesium lauryl sulfate, colloidal silica, talc, mixtures thereof, and others known in the art. A preferred lubricant is magnesium stearate, or mixtures of magnesium stearate with colloidal silica.
Excipients such as colouring agents and pigments may also be added to dosage forms in accordance with the present invention, and suitable colouring agents and pigments may include titanium dioxide and dyes suitable for food.
Flavours may be chosen from synthetic flavour oils and flavouring aromatics or natural oils, extracts from plants, leaves, flowers, fruits and so forth and combinations thereof. These may include cinnamon oil, oil of wintergreen, peppermint oils, bay oil, anise oil, eucalyptus, thyme oil. Also useful as flavours are vanilla, citrus oil, including lemon, orange, grape, lime and grapefruit, and fruit essences including apple, banana, pear, peach, strawberry, raspberry, cherry, plum, pineapple, apricot and so forth.
With reference to the pharmocokinetic performance of pharmaceutical compositions in accordance with the present invention, it will be appreciated that the parameters that are commonly used in the art to describe the in vivo performance of a formulation (or the bioavailability) are C max (the maximum concentration of the active in the blood) and, as mentioned previously, AUC (area under the curve—a measure of the total amount of drug absorbed by the patient). These are also the parameters Used by regulatory agencies around the world to assess bioequivalence of different formulations. For instance, to be considered bioequivalent, the 90% confidence interval for the ratio of the test to reference product (using natural log-transformed data) for C max and AUC are within the range of 80 to 125%.
By utilising compositions in accordance with the present invention, it has been found that drugs previously considered to present bioavailability problems may be presented in dosage forms with superior bioavailability. For instance, and as will be described in more detail below with respect to two examples, where the drug is itraconazole the inventive compositions have produced formulations that are not considered bioequivalents to, but have at least twice the bioavailability of, a commercially available itraconazole product (Sporanox™). Additionally, and again in comparison with Sporanox™, the inventive compositions have produced formulations that have reduced food effect and thus need not be administered with food (unlike Sporanox™).
Furthermore, the present invention also provides a pharmaceutical composition in the form of a solid dispersion of a polymer with acidic functional groups (preferably a polycarboxylic acid such as a hydroxypropyl methylcellulose phthalate) and an azole antifungal drug (such as itraconazole), wherein in vitro the composition forms a suspension. Preferably, the composition upon administration forms a suspension at a pH in the range of 4.0 to 8.0, but more preferably in the range 5.5 to 7.5, and may provide acceptable absorption in the intestines.
The present invention further provides a pharmaceutical composition in the form of a solid dispersion of a hydroxypropyl methylcellulose phthalate and a practically insoluble drug, wherein the composition forms a suspension in vitro in the pH range of 4.0 to 8.0 (preferably 5.5 to 7.5) and preferably provides acceptable absorption in the intestines.
Finally, in a preferred form the present invention is a pharmaceutical composition in the form of a solid dispersion of itraconazole that provides a mean C max of at least 100 ng/ml when a dose of 100 mg of itraconazole is given in the fasted state. A more preferred form is such a formulation of itraconazole that provides a mean C max of 150 to 250 ng/ml, when a dose of 100 mg of itraconazole is given in the fasted state.
A further form of the present invention is a pharmaceutical composition in the form of a solid dispersion of itraconazole that provides a mean AUC at least 800 ng·h/ml when a dosage of 100 mg of itraconazole is given in the fasted state. A more preferred form is such a solid dispersion of itraconazole that provides a mean AUC of 1300 to 2300 ng·h/ml, when a dose of 100 mg of itraconazole is given in the fasted state.
For formulations in accordance with the present invention containing drugs other than itraconazole it is preferred that the bioavailability of the drug as compared to the drug per se is improved by at least 50% and more preferably 100%, in terms of AUC.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made to examples that embody the above general principles of the present invention. However, it is to be understood that the following description is not to limit the generality of the above description.
Example 1
To produce the solid dispersion, a solution was prepared by dispersing HP-50 (60 g) in methylene chloride (1200 g) and then adding itraconazole (40 g) and stirring to form a pale brown solution. This solution was then spray dried to form a powder.
A portion (38.96 g) of this spray dried powder was then blended with sodium starch glycolate (14.87 g) and colloidal silicon dioxide (Aerosil 200)(0.75 g) in a mortar and pestle for 5 minutes. Magnesium stearate (1.11 g) was added to the blend from the mortar and the mixture tumble blended until uniform.
This powder blend was then filled into size 0 gelatin capsules by hand. Each capsule was filled with 364 to 378 mg of powder, containing nominally 98 to 102 mg of itraconazole.
These capsules were tested in a standard USP type II dissolution bath (paddle method). A capsule was weighted with stainless steel wire and then dropped into 900 ml of dissolution media consisting of 0.05 M phosphate buffer solution adjusted to pH 6.0. Samples of this media were extracted at appropriate time intervals through a 10 micrometer filter and the content of itraconazole in the sample assayed using a HPLC method. Both the media in the dissolution bath and the extracted, filtered samples were cloudy in appearance. This test was also performed using 900 ml of hydrochloric acid acidic media (pH 1.2, 0.06 M HCl). In this case both the media and the samples were clear.
The measured amount of itraconazole present in the samples, as a percentage of the total possible amount, after various times in the test described above is presented in the table below. For comparison the results of the same tests performed on a marketed itraconazole capsule (Sporanox™) are also tabulated. Sporanox™ produced clear solutions in both media.
pH 1.2 media, 75 rpm, paddles
pH 6.0 media, 100 rpm, paddles
Time
Sporanox ™
Test
Time
Sporanox ™
Test
(min)
98P0800E
Example 1
(min)
98P0800E
Example 1
0
0
0
0
0
5
1.9
4
5
1.1
4
10
5.2
6.4
10
1.2
20.2
30
42.3
9.9
30
2.2
58.5
45
56.1
11.6
45
2.8
69.7
60
64
13
60
3.2
76.4
120
76.2
16.6
120
3.7
77.6
180
18.8
180
82.3
240
21.1
240
81.1
Example 2
To produce the solid dispersion, a solution was prepared by dispersing HP-50 (420 g) in methylene chloride (8400 g) and then adding itraconazole (280 g) and stirring to form a pale brown solution. This solution was then spray dried to form a powder.
A portion (292 g) of this spray dried powder was then blended with sodium starch glycolate (93.6 g) and colloidal silicon dioxide (Aerosil 200)(5.6 g) in a Collette mixer at high speed for 5 minutes. Magnesium stearate (8.8 g) was added to the blend from the Collette mixer and the mixture tumble blended until uniform.
This powder blend was then filled into size 0 gelatin capsules by hand. Each capsule was filled with 345 to 359 mg of powder, containing nominally 98 to 102 mg of itraconazole.
These test capsules were utilised in a pharmacokinetic study. 8 male volunteers were dosed with one 100 mg capsule after an overnight (10 hour) fast. The capsules were dosed with 240 ml water. At appropriate time intervals blood samples were taken from the subjects and the concentration of itraconazole in the plasma determined. The study was performed in a randomised 2 way crossover fashion with subjects receiving 100 mg itraconazole as a marketed capsule (Sporanox™) or as the test formulation described in example 2 above. The alternate dose was taken after a 2 week washout period.
A plot of the mean blood levels measured is shown in FIG. 1 .
The data was analysed and the following standard mean pharmacokinetic parameters were obtained.
Sporanox ™ capsule
Parameter
Example capsule
(Lot 98P0800E)
Ratio
C max (ng/ml)
182.6
56.0
326%
T max (h)
2.94
3.44
85.5%
AUC (ng · h/ml)
1776
622
285%
AUC inf (ng · h/ml)
1875
664
282%
It can be seen from these results that significantly higher plasma itraconazole levels are obtained from the formulation described in the example than the marketed capsule form under these conditions.
Indeed, it was expected that the itraconazole formulation of this invention would have a later T max (time, to maximum blood concentration of active) than Sporanox™, due to the use of an enteric polymer, which should not have solublised until after passing through the stomach. This is in comparison to the water-soluble polymers used in Sporanox™ that would solublise in the stomach.
However, it can be seen from the above data that the T max of the formulation of the present invention is at least similar to the T max of Sporanox™, if not shorter than it. Together with the greatly increased C max , this result was surprising.
Example 3
Test capsules from Example 2 containing 100 mg of itraconazole were also utilised in a pharmacokinetic study under fed conditions, primarily for comparison with the pharmacokinetic results of Example 2 to determine whether there was any food effect.
The study was again conducted as a single dose, crossover study in 8 health male adult subjects, but underfed conditions. The subjects commenced eating a standard high fat breakfast 20 minutes prior to dose administration, having fasted for at least 10 hours prior to that.
A two week washout period between administration of the dose for each of the two treatments was again used, and the comparative product was again two 100 mg itraconazole capsules marketed as Sporanox™.
At appropriate time intervals blood samples were taken from the subjects and the concentration of itraconazole in the plasma determined.
A plot of the mean blood levels from the fasted study of example 2 (Fasted Study CM4799) and the fed study of Example 3 (Fed Study CM6000) is shown in FIG. 2 .
The data from the fed study of Example 3 was analysed and the following mean standard pharmacokinetic parameters were obtained:
Example 3 Capsule
Example 2 Capsule
Parameter
(Fed)
(Fasted)
C max (ng/ml)
148.20
182.6
T max (h)
10.25
2.94
AUC (ng · h/ml)
1806
1776
AUC inf (ng · h/ml)
1997
1875
It can be seen from these results that the example formulation produces plasma profiles considered bioequivalent in terms of AUC under fasting and fed conditions, due to the AUC under fed conditions being about 102% of the AUC under fasted conditions, which is well within the range of 80 to 120%. This is an indication that the total amount of drug absorbed over time is essentially equivalent under fed and fasted conditions.
Finally, it will be appreciated that there may be other variations and modifications to the compositions described herein that are also within the scope of the present invention. | The present invention provides a pharmaceutical composition of a practically insoluble drug, wherein the composition may be administered with food or without food. The composition may be in the form of a solid dispersion of the practically insoluble drug and a polymer having acidic functional groups, and the composition may in vitro form a suspension. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to the field of analog integrated circuit design and, more particularly, to oscillator and timer design.
[0003] 2. Description of the Related Art
[0004] Oscillators play a prominent role in the functionality of a large portion of today's analog and digital systems. Typically, oscillators, also referred to as astable multivibrators, are electronic circuits that convert energy from direct-current sources into periodically varying electrical signals, or voltages. In other words, an oscillator typically operates by utilizing the electrical behavior of its circuit elements to convert a steady state input signal into a periodic, time variant output signal. In some implementations the signal produced by an oscillator may be sinusoidal in appearance, such as a sine wave, in other implementations it may appear as a square wave, triangular wave, or a variety of other repeatable signals. Many of today's integrated circuits that require oscillators, such as timer circuits and Phase-Locked Loops (PLLs), need to include the oscillators on-chip in order to meet cost and area requirements. The behavior of such on-chip oscillators is typically affected by the technology used to fabricate the integrated circuit. For example, many widely used fabrication processes today are based on complementary metal-oxide-semiconductor (CMOS) technology, where each specific qualified CMOS process varies slightly from another.
[0005] One common type of oscillator is the relaxation oscillator. Typically a relaxation oscillator achieves its oscillating output by charging a capacitor to some event or switching threshold. The event discharges the capacitor, and its recharge time determines the repetition time of the events or switching. Similarly, an oscillating output could also be achieved by discharging instead of charging the capacitor to reach the event or switching threshold. Typically the capacitor is charged through a resistor, where the values of the resistor and the capacitor, referred to as the RC time constant, determine the rate, or frequency, of the oscillation. For example, decreasing the value of the resistor may increase the oscillation frequency, and increasing the value of the resistor may decrease the oscillation frequency. In the case of a typical relaxation oscillator whose frequency is determined by an RC time constant, any fabrication process variation on any of the parameters (namely R and C) will typically result in a shift in the oscillator frequency.
[0006] One widely used oscillator topology in the art is found in the popular IC555 timer circuit, which has been on the market since the mid-Nineteen Sixties. The IC555 timer is frequently configured in a free-running mode, where a capacitor between an upper threshold, which is determined by a first comparator, and a lower threshold, which is determined by a second comparator, is resistively charged and discharged. The frequency of oscillation of the timer may be affected by various factors, including finite comparator gain and offset voltage, temperature variations, and process shift in silicon processing.
[0007] The IC555 has been widely used in the art, and methods have been developed to minimize changes in the frequency of oscillation resulting from temperature effects. Efforts have also been made to counteract the effects of finite comparator gains and offset voltages, by making the frequency of oscillation a value independent of the supply voltage used by the respective circuits. Typically, these solutions employ discrete precision resistor and capacitor components that are external to the oscillator circuit in order to avoid the problems caused by process shift. As a result, these solutions are generally not ideal for systems or circuits that require an integrated oscillator with reduced pin counts. When working within generally tight operational tolerances, a trim capability of the circuit may be required to make the necessary adjustments needed for achieving proper circuit operation over variations present in silicon processing.
[0008] Trimming is typically accomplished by cutting (or blowing) fuses, which results in a permanent change. The outputs of the fuses are generally a couple of digital bits, also called trim bits. The trim bits are sometimes implemented as a programmable option, where during power-up they are latched to pre-specified levels. For greater flexibility the trimming is many times performed using a combination of both methods. Typically, when performing trimming for an oscillator, the digital bits select different RC time constants to set the correct output frequency regardless of any process shift of the internal integrated components. Generally a bank of capacitors and/or a bank of resistors are employed for selecting the appropriate RC time constant. If the effects of the process shift are diminished, the trim range can be effectively decreased leading to smaller area requirements for the capacitor bank and/or resistor banks.
[0009] Therefore, there exists a need for a system and method for designing an integrated relaxation oscillator that exhibits minimal change in the frequency of oscillation caused by process variation, by improving sensitivity to component variation due to process shift while minimizing the area requirements for capacitor banks and/or resistor banks used during trimming.
SUMMARY OF THE INVENTION
[0010] In one set of embodiments, the invention comprises a system and method for designing an integrated oscillator circuit while minimizing the effect of the resistor variation in the frequency of oscillation caused by a shift in the manufacturing process. In one embodiment, an oscillator is designed using two different structural types of resistors that are comprised in the ‘RC time constant’ of the frequency of oscillation. The structural types may be selected within an available process and may include p-diffusion (p+), n-diffusion (n+), n-well, p-well, pinched n-well, pinched p-well, poly-silicon (p doped or n doped), and metal (layer 1 , 2 , 3 or 4 ) for a given CMOS process technology, for example. The different types of resistors that are selected will have, by type, statistically independent process variations. In one embodiment, the resistor coupled to the oscillator output and comprised in the RC time constant is divided into two equal parts of each structural type. The contribution made to the frequency variation by the process shift of the resistor types can be considered independent events that follow a Gaussian probability distribution. The combined effect may be a distribution with standard deviation equal to the square root of the sum squares of the individual standard deviations. By obtaining standard deviations that are close, the overall standard deviation may decrease by approximately 29% compared to the standard deviation resulting from using only a single type of resistor.
[0011] A typical relaxation oscillator, such as an IC555 type timer, may include a resistor string with equal values to generate two threshold voltages, in one case two-thirds of a supply voltage and one-third of the supply voltage, as inputs to a window comparator. In one embodiment, the comparator outputs are tied to the inputs of an SR-flip-flop, which may drive a charging or discharging of a capacitor in a corresponding RC path external to the resistor string. For proper functioning the capacitor voltage may be regulated to fall within the range of the threshold voltages. The RC time constant may determine the frequency of the pulse at the output of the SR-flip-flop, which may eventually be used as the oscillator output. Any increase in the frequency due to an increase in sheet resistance of the resistor external to the resistor string may partially be compensated by a decrease in the window of threshold voltages. In one embodiment, the resistor outside the resistor string is made of a single type, but the resistor string is broken up into two different types. An improvement of about 34% in standard deviation may thus be obtained. In an alternate embodiment, the resistor string is made of a single type while the resistor external to the resistor string is broken into different types.
[0012] Thus, various embodiments of the invention may provide a means for designing an integrated relaxation oscillator that exhibits minimal change in the frequency of oscillation caused by process variation. Improved sensitivity to component variation due to process shift is achieved by selecting the resistors included in the RC time constant of the oscillator to be of different structural types. Each type will exhibit statistically independent process variations. Thus, improvement in the performance of the oscillator may be achieved with a reduced trim requirement and without using external resistors. The invention utilizes Lyapunov's extension of the Central Limit Theorem for statistically uncorrelated events to desensitize the effect from some possible causes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The foregoing, as well as other objects, features, and advantages of this invention may be more completely understood by reference to the following detailed description when read together with the accompanying drawings in which:
[0014] FIG. 1 illustrates one embodiment of an integrated oscillator circuit proposed by the present invention;
[0015] FIG. 2 illustrates a chart depicting frequency variation with respect to process shift of individual resistor types as pertaining to the embodiment of the integrated oscillator shown in FIG. 1 ;
[0016] FIG. 3 illustrates an alternate embodiment of an integrated oscillator circuit proposed by the present invention;
[0017] FIG. 4 illustrates a chart depicting frequency variation with respect to process shift of individual resistor types as pertaining to the embodiment of the integrated oscillator shown in FIG. 3 .
[0018] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. Note, the headings are for organizational purposes only and are not meant to be used to limit or interpret the description or claims. Furthermore, note that the word “may” is used throughout this application in a permissive sense (i.e., having the potential to, being able to), not a mandatory sense (i.e., must).” The term “include”, and derivations thereof, mean “including, but not limited to”. The term “connected” means “directly or indirectly connected”, and the term “coupled” means “directly or indirectly connected”.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] As used herein, “structure type” refers to the physical structure of an individual resistive element, or resistor implemented on an integrated circuit for a given process. For example, for a given CMOS process a resistor may be implemented to be of one of a variety of structure types, which may include n-diffusion, p-diffusion, n-well, p-well, pinched n-well, pinched p-well, poly-silicon and metal. When configured on an integrated circuit, a single “resistance” may be constructed as a single resistor or as two or more resistors connected together, where each individual resistor may be of a different structure type. When constructed of more than one resistor, the nominal value of the resistance may be equivalent to the sum of the nominal values of the resistors that make up the resistance. A “resistor string” refers to resistances connected in series, with connective taps available at the terminals of the resistances. Similarly, a “capacitance” may be constructed as a single capacitor or as two or more capacitors connected together. When constructed of more than one capacitor, the nominal value of the capacitance may be equal to the sum of the nominal values of the capacitors that make up the capacitance.
[0020] The term “integrated oscillator” refers to an oscillator whose components are configured on one integrated circuit. Furthermore, an integrated oscillator may itself be configured on one integrated circuit together with a system that uses the oscillator. The word “alternately” is meant to imply passing back and forth from one state, action, or place to another state, action, or place, respectively. For example, “alternately charging and discharging a node” would mean charging the node, then discharging the node, then charging the node, then discharging the node, and so on.
[0021] FIG. 1 illustrates one embodiment of an integrated oscillator circuit proposed by the present invention. In this embodiment, comparators COMP 1 104 and COMP 2 106 are coupled to inputs S 132 and R 134 of SR-Flip-Flop (SRFF) 102 , respectively, where output Q of SRFF 102 represents oscillator output (OscOut) 130 . A resistor string including R 1 110 , R 2 112 , and R 3 114 may be connected in a configuration to generate threshold voltages V th1 136 and V th2 138 . In this configuration, R 1 110 couples a supply voltage V dd 150 to an inverting input 162 of COMP 1 104 , while R 2 112 couples node V th1 136 to node V th2 138 itself coupled to a non-inverting input 164 of COMP 2 106 , and R 3 114 couples node Vth 2 138 to a common ground (GND) 152 . Resistors R 4 116 and R 5 118 may couple OscOut 130 to capacitor C 120 , with the other terminal of C 120 connected to GND 152 . In one embodiment, C 120 is also coupled to node VC 140 which connects inverting input 166 of COMP 2 106 and non-inverting input 160 of COMP 1 104 . SRFF 102 operates to drive the charging and discharging of C 120 through R 4 116 and R 5 118 . By keeping the voltage across C 120 within the bounds established by V th1 136 and V th2 138 , stable operation of the oscillator may be achieved.
[0022] Referring again to FIG. 1 , threshold voltages measured at node V th1 136 and node V th2 138 may be expressed as follows:
V th1 = ( R 2 + R 3 ) V dd ( R 1 + R 2 + R 3 ) ( 1 ) V th2 = ( R 3 ) V dd ( R 1 + R 2 + R 3 ) . ( 2 )
For the oscillator shown in FIG. 1 , C 120 is being charged while the voltage value measured at node VC 140 changes from being equivalent to the voltage value measured at node V th2 138 to being equivalent to the voltage value measured at node V th1 136 . A time period (T 1 ) elapsed during charging C 120 may be expressed by the equation:
T 1 = ( R 5 + R 4 ) C ln ( R 1 + R 2 R 1 ) . ( 3 )
Similarly, as the voltage value measured at node V c 140 changes from being equivalent to the voltage value measured at node V th1 136 to being equivalent to the voltage value measured at node V th2 138 , C 120 is discharged. A time period (T 2 ) elapsed during discharging C 120 may be expressed by the equation:
T 2 = ( R 5 + R 4 ) C ln ( R 2 + R 3 R 3 ) . ( 4 )
A resulting total time period of the oscillation (T) may be expressed as:
T = ( R 5 + R 4 ) C ln [ ( R 2 + R 3 R 3 ) ( R 1 + R 2 R 1 ) ] . ( 5 )
[0026] The resistor values as they appear in equation (5) represent nominal values, which are prone to variations resulting from process shifts during manufacturing. The level of variation for a respective resistor will be dependent on the structure type chosen for the respective resistor. While process shifts experienced by each respective structure type may be similar, the process shift for each respective structure type may also depend on variables that do not affect any of the other process shifts. Therefore, if the resistors in equation (5) are selected to be of more than one structure type, changes in nominal values of the different resistors may be considered separately and grouped by structure type. In other words, a process shift associated with a respective structure type may be considered as contributing to a change in value of a resistor of the respective structure type independently from a process shift associated with another structure type contributing to a change in value of a resistor of the other structure type. From equation (5) it follows that a change in nominal resistor value results in a change in the period of oscillation (T).
[0027] As indicated by equations (1) and (2), (and also equations (10) and (11) below) selection of the nominal resistor values for the resistor string may determine threshold voltages V th1 136 and V th2 138 . For example, in a first embodiment, the value of R 2 112 may be chosen to be twice the value of R 1 110 and also twice the value of R 3 114 , resulting in the value of V th1 equaling three-fourths the value of V dd , or ¾*V dd , and the value of V th2 equaling one-fourth the value of V dd , or ¼*V dd , nominally. Similarly, in a second embodiment, an equal value each for R 1 110 , R 2 112 , and R 3 114 may be selected, which would result in the value of V th1 equaling ⅔*V dd , and the value of Vth 2 equaling ⅓*V dd , nominally. In the first embodiment mentioned above, COMP 2 106 has to operate reliably for a lower common mode voltage close to GND 152 than in the second embodiment. Also, since V th1 136 is higher in the first embodiment than in the second embodiment, COMP 1 104 has to operate reliably for a higher common mode voltage close to V dd 150 in the first embodiment than in the second embodiment. For lower values of V dd , considering process corners and supply variations, threshold voltages V th1 136 and V th2 138 may move further, which may result in further constraints on the design of COMP 1 104 and COMP 2 106 . Therefore, the second embodiment cited above may be preferred in some cases, though the first embodiment may also be implemented, and other embodiments may use a variety of different values for R 1 , R 2 , and R 3 .
[0028] In one embodiment, different structure types (Type 1 and Type 2) are selected for resistors R 1 , R 2 , R 3 , R 4 , and R 5 , such that R 1 =R (Type 1), R 2 =R (Type 1), and R 3 =R (Type 1), where ‘R’ represents a nominal value of each resistor in the resistor string, and R 4 =R ext /2 (Type 2) and R 5 =R ext /2 (Type 1), where ‘R ext /2’ represents a nominal value of each resistor outside the resistor string. In other words, R 1 , R 2 , R 3 , and R 5 may be selected to be of structural Type 1, while R 4 may be selected to be of structural Type 2. Considering equation (5), ‘R’ may be substituted for R 1 , R 2 , and R 3 , and similarly, ‘R ext /2’ may be substituted for R 4 and R 5 . Following from equation (5) the resulting oscillation period T may then be nominally written as:
T=R ext C ln[4]. (6)
[0029] In order to describe process variation, a standard deviation term may be needed for each mean value represented by ‘R’ and ‘R ext ’ respectively. The standard deviation term may be referred to as a fractional term or a percentage value with respect to the mean value. It is customary for those skilled in the art to account for a process shift of up to 3 times the standard deviation, which is symbolically specified as “3-sigma”. The fractional 3-sigma process shift of a Type 1 resistor may be designated as Δ l and the fractional 3-sigma process shift of a Type 2 resistor may be designated as A 2 . For example, the actual value for a Type 1 resistor with process shift may now be expressed as R actual =R*(1+Δ 1 ). The oscillation period for Type 1 resistor variation may then be expressed as:
T + Δ T 1 = R ext C ( 1 + Δ 1 2 ) ln [ 4 ] , ( 7 )
and the oscillation period for Type 2 resistor variation may be expressed as:
T + Δ T 2 = R ext C ( 1 + Δ 2 2 ) ln [ 4 ] . ( 8 )
[0031] In equation (8) ΔT 1 and ΔT 2 represent the individual and independent contributions of the process shift of structure Type 1 and the process shift of structure Type 2 to the overall change in oscillation frequency. The overall change in the period of oscillation (ΔT) for both of those events according to an extended central limit theorem for statistically uncorrelated, or independent, events may be expressed as:
Δ T ={square root}{square root over ((Δ T 1 ) 2 +(Δ T 2 ) 2 )}. (9)
[0032] FIG. 2 shows a chart illustrating frequency variation with respect to process shift of individual resistor types as pertaining to the embodiment of the oscillator shown in FIG. 1 . The horizontal axis represents a percent change in resistor value due to the process shift, and the vertical axis represents a percent change in the period of oscillation of the oscillator output. As expressed in the chart, if for example both Type 1 and Type 2 show a 20% process shift, then the corresponding change in period of oscillation for both types is 10%, respectively. The overall change in the period of oscillation may be expressed as the square root of the sum of squares of both shifts, which for the aforementioned values would come to a value of 14.14% when considering both process shifts from FIG. 2 .
[0033] FIG. 3 illustrates another embodiment of an integrated oscillator circuit proposed by the present invention. In this embodiment, comparators COMP 1 304 and COMP 2 306 are coupled to inputs S 332 and R 334 of SRFF 302 , respectively, where output Q of SRFF 302 represents OscOut 330 . A resistor string including R 1 310 , R 2 312 , R 3 314 , and R 4 316 may be connected in a configuration to generate threshold voltages V th1 336 and V th2 338 . In this configuration, R 1 310 couples a supply voltage V dd 350 to an inverting input 362 of COMP 1 304 , while R 2 112 couples node V th1 336 to node V th2 338 itself coupled to a non-inverting input 364 of COMP 2 306 , and R 3 114 couples node V th2 338 to R 4 316 , which is then coupled to GND 352 . Resistor R 5 318 may couple OscOut 330 to capacitor C 320 , with the other terminal of C 320 connected to GND 352 . In one embodiment, C 320 is also coupled to node V c 340 which connects inverting input 366 of COMP 2 306 and non-inverting input 360 of COMP 1 304 . SRFF 302 operates to drive the charging and discharging of C 320 through R 5 318 . By keeping the voltage across C 320 within the bounds established by V th1 336 and V th2 338 , stable operation of the oscillator may be achieved, similar to the operation of the oscillator in the embodiment of FIG. 1 .
[0034] Referring again to FIG. 3 , threshold voltages measured at node V th1 336 and node V th2 338 may be expressed as follows:
V th1 = ( R 2 + R 3 + R 4 ) V dd ( R 1 + R 2 + R 3 + R 4 ) ( 10 ) V th2 = ( R 3 + R 4 ) V dd ( R 1 + R 2 + R 3 + R 4 ) . ( 11 )
As seen from FIG. 3 and equations (10) and (11), R 3 314 and R 4 316 may together functionally represent a single resistor when considering the voltage distribution at nodes V th1 336 and V th2 338 . For the oscillator shown in FIG. 3 , C 320 is being charged in a manner similar as described for C 120 in the oscillator of FIG. 1 . In other words, C 320 is charged while the voltage value measured at node V c 340 changes from being equivalent to the voltage value measured at node V th2 338 to being equivalent to the voltage value measured at node V th1 336 . A time period (T 1 ) elapsed during charging C 320 may be expressed by the equation:
T 1 = R 5 C ln ( R 1 + R 2 R 1 ) . ( 12 )
Similarly, as the voltage value measured at node V c 340 changes from being equivalent to the voltage value measured at node V th1 336 to being equivalent to the voltage value measured at node V th2 338 , C 320 is discharged. A time period (T 2 ) elapsed during discharging C 320 may be expressed by the equation:
T 2 = R 5 C ln ( R 2 + R 3 + R 4 R 3 + R 4 ) . ( 13 )
A resulting total time period of the oscillation (T) may be expressed as:
T = R 5 C ln [ ( R 2 + R 3 + R 4 R 3 + R 4 ) ( R 1 + R 2 R 1 ) ] . ( 14 )
[0038] Performing an analysis similar to that performed for the oscillator in the embodiment shown in FIG. 1 , different structure types (Type 1 and Type 2) may again be selected for resistors R 1 , R 2 , R 3 , R 4 , and R 5 . In one embodiment, R 1 =R (Type 1), R 2 =R (Type 2), R 3 =R/2 (Type 1), and R 4 =R/2 (Type 2) where ‘R’ represents a nominal value of each resistor in the resistor string, and R 5 =R ext (Type 1) where ‘R ext ’ represents a nominal value of the resistor outside the resistor string. As described above, compensating for effects of process shift in the charging/discharging time of C 320 may be accomplished by varying the threshold levels of the comparators through the selection of different types for respective resistors in the resistor string, where, for example, R 3 314 and R 4 316 may together be considered as one functional element divided into two parts, each part being of a different structure type. Therefore, considering equation (14), ‘R’ may be substituted for R 1 and R 2 , ‘R/2’ may be substituted for R 3 and R 4 , and similarly, ‘R ext ’ may be substituted for R 5 . Following from equation (13) the resulting oscillation period T may then be nominally written as:
T=R ext C ln[4] (15)
[0039] Again, in order to describe process variation, a standard deviation term may be needed for each mean value represented by ‘R’, and ‘R ext ’respectively. The fractional 3-sigma process shift of a Type 1 resistor may again be designated as Δ 1 and the fractional 3-sigma process shift of a Type 2 resistor may again be designated as Δ 2 . The oscillation period for Type 1 resistor variation may then be expressed as:
T + Δ T 1 = R ext C ( 1 + Δ 1 ) ln [ ( 2 + Δ 1 / 2 1 + Δ 1 / 2 ) ( 2 + Δ 1 1 + Δ 1 ) ] , ( 16 )
and the oscillation period for Type 2 resistor variation may be expressed as:
T + Δ T 2 = R ext C ln [ ( 2 + 3 Δ 2 / 2 1 + Δ 2 / 2 ) ( 2 + Δ 2 1 ) ] . ( 17 )
The overall change in the period of oscillation (ΔT) for both of those events according to an extended central limit theorem for statistically uncorrelated, or independent, events may again be expressed as:
Δ T ={square root}{square root over ((Δ T 1 ) 2 +(Δ T 2 ) 2 )}. (18)
[0042] FIG. 4 shows a chart illustrating frequency variation with respect to process shift of individual resistor types as pertaining to the oscillator shown in the embodiment of FIG. 3 . The horizontal axis again represents a percent change in resistor value due to the process shift, and the vertical axis again represents a percent change in the period of oscillation of the oscillator output. As expressed in the chart, if both Type 1 and Type 2 show a 20% process shift, the corresponding change in period of oscillation for Type 2 is 10%, and the corresponding change in period of oscillation for Type 1 is 8.44%. Therefore, the shift in oscillation frequency for Type 1 is further reduced when compared to the shift in oscillation frequency for Type 1 in FIG. 2 . The overall change in the period of oscillation may again be expressed as the square root of the sum of squares of both shifts, which for the aforementioned values would come to a value of 13% when considering both process shifts from FIG. 4 . This represents a 1% improvement over the previous compounded percentage value of 14.14% (from FIG. 2 ), and an overall 5% improvement when compared to all resistors being of a single type.
[0043] Thus, various embodiments of the systems and methods described above may facilitate design of an integrated relaxation oscillator that exhibits minimal change in the frequency of oscillation caused by process variation, thereby minimizing the area requirements for capacitor banks and/or resistor banks used during trimming.
[0044] Although the embodiments above have been described in considerable detail, other versions are possible. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications. Note the section headings used herein are for organizational purposes only and are not meant to limit the description provided herein or the claims attached hereto. | A system and method for designing an integrated relaxation oscillator that exhibits reduced change in the frequency of oscillation caused by process variation. Improved sensitivity to component variation due to process shift is achieved through using more than one structure type when implementing the resistors affecting the RC time constant and threshold (trip point) voltages of the oscillator. Structure types are related to the fabrication process and for a CMOS process include, but are not limited to n-diffusion, p-diffusion, n-well, p-well, pinched n-well, pinched p-well, poly-silicon and metal. Each structure type exhibits statistically independent process variations, allowing for application of Lyapunov's extension of the Central Limit Theorem for statistically uncorrelated events to desensitize the effect from different possible causes. Thus, improvement in the performance of the oscillator may be achieved with a reduced trim requirement and without using external precision resistors. | 7 |
FIELD OF THE INVENTION
The invention relates to tools for removing material that has been nailed in place, such as asphalt shingles and roofing materials of all types, and flooring materials such as tile, carpet and wood strips. It is also useful in removing siding, panels, and moldings.
BACKGROUND TO THE INVENTION
When a building, or part of one, is to be taken apart, if material is to be salvaged, nails must be extracted. Some parts of buildings, notably roofing materials, are intended to be replaced many times in the life of the building. Roofing materials, such as shingles, are nailed in place, so removing the shingles for replacement requires extracting the nails. For efficiency, it is normal to lift the roofing material and the nail together, until the nail is fully extracted and the roofing material is detached from the building. The roofing material and the nail can then be discarded, and the wooden roof that has been exposed will be retained, possibly with some repairs, and covered with new roofing material.
This description will mainly speak in terms of lifting shingles, for brevity. That is an important use of the tool, but it must be remembered that the tool is useful for removing many types of building materials held by nails.
Most nails have heads that provide a grip for a pulling tool. Most pulling tools have a slot to grip the nail below the head, and operate as a lever with the fulcrum on the surface in which the nail is embedded, such as the roof. The common claw hammer is an example. Many more elaborate tools have been developed, and patented, but there remains room for improvement in respect of the smoothness of operation in guiding the tool around the nail, and in levering the nail out of the material in which it is embedded.
U.S. Pat. No. 1,218,145 to Whittier discloses, way back in 1917, a shingle stripper that is a blade having V-shaped slots on the front and back edges, and the bottom surface (and top surface, but that is irrelevant) having two dihedral planes creating a single ridge fulcrum where the two planes meet. The present invention improves on the shape of the slots, and provides a continuous fulcrum as a curved rocker.
U.S. Pat. No. 4,203,210 to Hadlick discloses a shingle stripper that is essentially a shovel with V-shaped slots at the front edge, and a separate fulcrum affixed at the rear edge. Again, the present invention improves on the shape of the slots, and provides a continuous fulcrum like a curved rocker.
U.S. Pat. Des. 392,687 to Gracy et al. discloses a multi-purpose wrecking bar that has a flat bottom, so the only fulcrum is the rear edge. Gracy discloses slots with straight sides that taper either continuously, or in two different tapers, and some end the tapering straight side with a round hole.
U.S. Pat. No. 4,466,188 to Svendsgaard discloses a roofing remover that is wedge shaped and has slots that are straight parallel sides ending in a rounded end. The bottom surface is flat, but the tool as a whole is wedge shaped for forcing up the roofing material after the nail has been extracted. Extracting the nail involves lifting the nail by the slots, and the only fulcrum for lifting is the rear edge.
U.S. Pat. No. 5,280,676 to Fieni discloses an apparatus with slots having straight sides that taper in two different degrees, so the slot near the mouth of the slot converges rapidly and the remainder of the slot converges slowly or not at all. The bottom surface is almost all flat, but near the rear of the tool there is a bend that provides a ridge fulcrum before the rear edge comes into play as a fulcrum.
U.S. Pat. No. 6,125,720 to Gohman discloses a tool for removing roofing material that has slots much wider than a nail, and sub-slots within them that could seize a nail. All the slots have straight sides that taper narrower away from the leading edge. The blade is flat on the bottom (and top), but the manner of fastening it to the handle involves a curve that constitutes the rear edge for practical purposes. Most tools of this general type have the handle attached near the middle of the blade, but Gohman bends the blade and attaches the handle at the rear of the working surface of the blade. The bent rear edge of Gohman is not exactly a ridge fulcrum, but it is functionally different from the continuous curved rocker fulcrum of the present invention.
U.S. Design Pat. D439,126 to Gohman shows a thin blade with V-shaped teeth on the leading edge. The blade as a whole is partly flat and partly convex downward. It is quadrangular. The handle is attached at the rear of the blade, and the blade is not adaptable to have teeth on the rear edge. The prying force is delivered indirectly to the blade from the handle through an offset portion of the rear of the blade. As the blade has no reinforcing ribs or gussets, it is vulnerable to bending both along the main blade and in the offset joining the handle. This tool would require remarkably strong metal to operate with flexing.
U.S. Pat. No. 5,836,222 to Harpell discloses a shingle removing tool having slots with parallel sides, and an alternative with V-shaped slots. The bottom surface is flat, so the only fulcrum for lifting nails is the rear edge of the tool. The slots are simply parallel sides with rounded leading edges between them.
U.S. Pat. No. 6,029,545 to Harpell discloses a roofing tool having slots with parallel sides. The largest part of the bottom surface is flat, but blade is thinned near the leading edge so the bottom surface has a small portion near the leading edge that is a flat plane at a small angle to the rest of the bottom surface. Where the two planes meet, there is a ridge across the blade that serves as a fulcrum when the nail is first lifted. After a small advance of the nail, the fulcrum will shift to the rear edge of the blade, so this tool has two fulcrums, rather than the continuous rocker fulcrum of the present invention.
U.S. Pat. No. 6,098,292 to Harpell discloses a demolition tool having either no slots, or slots with parallel sides. The leading edge is designed for cutting, but cutting is often not desired, and rather grabbing and lifting is desired. It has a flat bottom, although with a groove, so its only fulcrum for leveraging nails upward is the rear edge. It has a quadrangular outline, which does not conform to a partially lifted shingle, and its sharp straight edges tend to cut the shingle, which is undesirable.
U.S. Pat. No. 6,339,975 to Harpell discloses long teeth on each side with straight sides, directing nails into slots that are rounded at the bottom and at the end of the finger between slots, but essentially have parallel sides. The bottom surface is flat, so the only fulcrum for lifting nails is the rear edge. The long fingers are very aggressive to the shingle, tending to cut, and pushing the long fingers much farther ahead than the slots where the nail will be lifted is inconvenient and hard work.
Published US application 20070051210 by Harpell discloses a tool blade with slots having two different degrees of taper near the mouth, and parallel sides to complete the slot. The bottom surface is two planes at a small dihedral angle, proving a fulcrum near the middle of the blade. There is also an alternative of a bottom surface that is flat through the middle majority of the surface, with a plane diverging at a small dihedral angle at each end. The present invention will improve on the design of the slots, and will provide a continuous fulcrum as a curved rocker. Harpell also provides an “impact receiving member” which is some distance up the handle above the blade. The present invention provides the equivalent hammer horns at a location that will better deliver the effect of impact to where it is helpful.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the deficiencies noted in the prior art concerning tools for lifting building materials and associated nails. The invention guides itself around nails more smoothly than prior tools. The invention can be inserted under a shingle more smoothly because the envelope of its shape conforms to the shape that the shingle must take. The invention levers the nail more smoothly with a continuous rocking motion, starting with the most powerful prying force and smoothly advancing to the most rapid movement. In this summary, “smoothly” includes the meaning of easily, that is with less work, and it includes the meaning of proceeding without jerks and sudden stops, which is desirable for the comfort of the user.
All of the prior art uses nail gripping slots that do either little or nothing to guide the tool around the nail, or guide the nail with slanted straight edges that resist the movement of the tool. All of the prior art uses a small number of fulcrums, sometimes just the rear edge, and at other times an additional one, two, or three ridge fulcrums. The disadvantage of the rear edge fulcrum is that it is a long way from the nail to be lifted and the long lever arm gives poor leverage. The disadvantage of several added ridge fulcrums is that the shift from one to another as the extraction progresses causes a jerk in the movement of the handle which is tiresome to the user.
All of the prior art discloses essentially rectangular tools. The leading edge and the sides are straight, and typically at right angles. If their top is provided with two or more camming gussets to lift the shingles, they are the same height so the envelope of their lifting edges is planar. However, if the material being lifted is at all flexible, such as an asphalt shingle, the tool will be operating in a space under the lifted material that is semi-conical. The shingle is curved in all places where it is not contacting the roof. The lifted portion is like a bubble. When rectangular tools with straight edges are inserted into that bubble, they meet a lot of resistance and they do a lot of damage to the material being lifted. This is analogous to a square peg in a round hole. The lifting head of the present invention has an envelope that is curved, conforming to the curving bubble.
These and other objects, features, and characteristics of the present invention will be more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiments of the invention will now be described in detail with reference to the following drawings, in which:
FIG. 1 shows the lifting head from above.
FIG. 2 shows the design of slots, made of overlapping holes.
FIG. 3 a shows the forces at work in guiding the lifting head around a nail in the prior art, and FIG. 3 b shows those forces as the operate in the present invention.
FIG. 4 shows a side view of the lifting head.
FIG. 5 shows a side view of the whole tool, comprising the handle and the lifting head.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 , the lifting head has a front portion 1 that is larger than the rear portion 2 . The dividing line between front and rear passes through the handle mounting boss 3 , which is adapted for mounting a handle that is inclined to the rear (downward in the drawing). Each of front portion 1 and rear portion 2 are symmetrical left and right about a line passing through the centre of the handle mounting boss 3 .
The leading edge of the front portion 1 has slots in it, but if the slots are ignored for a moment, the imaginary envelope 8 of the leading edge is slightly curved so that side tips 6 and 7 are not as far forward as the leading edge between them. The sides 4 and 5 are slightly curved so that it is narrowest near the handle mounting boss 3 , widest about two-thirds of the distance from the boss to the leading edge, and less wide at the leading edge.
The curved outline has beneficial effects. Until the last nail in a shingle is reached, the shingle under which the leading edge is slipped will be held close to the roof by one or more nails on at least one side of the lifting head. When the lifting head grips a nail and raises the nail and the shingle together, the shingle will bend down on the side where there is another nail, and in the direction ahead of the tool. The shingle will tend to a semi-conical shape, curved with its highest point at the centre line of the lifting head. The curved front and sides of the lifting head are a better fit to the curving bottom surface of the lifted shingle than straight sides would be. If the leading edge were straight, the lifted shingle would have to lift equally across the width of the lifting head and then fall away at the sides. Such a design tends to encourage breaking of the shingle, which is less efficient because a smaller section is lifted and more broken sections of shingles remain to be dealt with individually. Straight sides and a straight leading edge would tend to cut into and break the shingles more than the curved sides and curved leading edge.
The entire front portion 1 of the lifting head can be imagined surrounded by an envelope which bridges over slots and ridges and is the smooth surface that would neatly encase the lifting head. An aspect of the invention is that such an envelope would have nothing but curved surfaces when viewed from any perspective. There are no straight lines in the envelope, except perhaps the small vertical sidewall that is the thickness of the blade.
Sides 4 and 5 curve outward as they leave side tips 6 and 7 for the reasons just discussed, but after some distance sides 4 and 5 continue curving so that the lifting head becomes narrower near the handle mounting boss 3 than at the leading edge. That narrowing reduces weight and cost, but it is not an essential feature. The narrowing near the mounting boss 3 also allows the hammer horns to project beyond the lifting head and so be more exposed for the purpose of being struck, without being long. A long hammer horn would have the disadvantage that blows on it tend to rotate the lifting head, which is unhelpful. The hammer horns are preferably located as close to the centreline as possible, because that maximizes the transfer of the force of a blow to the leading edge of the lifting head. In some tools known in the prior art, an element intended to receive blows is placed on the hosel or the handle, but that has the disadvantage that the force of the blow is partly dissipated by the resilience of the handle, and also the force has a vertical component that is wasted, and counterproductive, for the purpose of forcing the tool to lift nails and shingles.
The leading edge of the front portion 1 has a number of slots, into which nails will slide when the lifting head is pushed forward. All slots are formed from overlapping round holes. In other words, the sides of slots are all arcs of several circles that overlap, so no circle is complete. In principle, the slots could be formed by drilling a number of round holes, but that is not the practical way to produce the slots. In the embodiment shown, the central slot 11 and the two outer slots 12 and 13 are suitably formed from two overlapping holes, with the outer hole about 3 times the diameter of the inner one. The slots 15 , 16 midway between the centre and the sides are each suitably formed with a pair of inner holes, plus a pair of holes overlapping those inner holes and about three times the diameter of the inner holes, and finally a pair of still larger holes, overlapping the last-mentioned holes and overlapping each other. The use of round holes means that the sides of the slots are a series of arcs. Arcs are well suited for guiding the lifting head past the nail shaft until the end of the slot is reached, or until the slot is smaller than the nail shaft diameter. The nail shaft will be cupped by the arcuate side of the slot, and the head of the nail will extend over the top surface of the lifting head so that when the leading edge of the lifting head rises, the nail is pulled and the shingle is lifted.
FIG. 2 shows the circular nature of the sides of the slots. Circle 60 defines the arcs that are part of the outermost portion of a slot. Circle 61 defines the next portion of a slot, and circle 62 defines the smallest portion and end of a slot. Circles 61 and 62 are shown in separate slots, not overlapping circle 60 , but the shape of slots 15 and 16 is the same as a circle like 62 innermost overlapped by a circle like 61 next outwards, and circle 60 overlapping circle 62 in each of slots 15 and 16 . Circle 63 , defining part of slot 13 , would typically be about the same size as circle 61 , but the exact size of any circle, and so of any slot, is not critical to the invention.
It is common in the prior art to use converging sides of the slots, and when the nail reaches the slot width equal to the shaft diameter, the tool often goes a little farther and bites into the nail. That is undesirable because the nail clings to the tool, and may be cut right through or is at least easily broken where the bite occurred. Straight sides of a slot bite into the nail because they are tangent to the nail surface, and the point of contact is small so the force is concentrated. In the present invention the sides of the slot are not a straight tangent to the nail but approximately concentric with the nail. The contact is not at a point, but along a short arc, so the force is not concentrated at a point and the edge is less likely to bite into the nail.
Other known nail extracting tools of the pry-bar type usually have either slots with converging sides, as with the classic claw hammer, or slots with a change of angle along the sides so the leading portion of the slot is wider than the following portion. A common example of the latter type is a series of slots defined by a series of fingers having leading ends that taper to narrowness at the leading edge, which may be a rounded leading edge of each finger. A tool with multiple slots must have the slots spaced sufficiently apart that the fingers between them have enough material to be strong, keeping in mind that the material is necessarily thin since it must slip under the head of the nail. The tool will more readily slide around the shaft of the nail if the slot has a wide opening to find the nail and guide the tool around the shaft.
FIG. 3 a and FIG. 3 b illustrate the benefit of slots made of overlapping round holes. FIG. 3 a shows the prior art, where the side of the slot 30 is straight but inclined to the direction of motion of the tool, which is vertically upward in the drawing. The force moving the lifting head forward will resolve into a vector 20 moving the tool to the left by pushing on the nail 31 , and vector 21 pushing against the nail. A force equal to vector 21 is felt by the user, as the nail 31 pushes back on the tool 30 . Both vectors 20 and 21 are constant from the moment of first contact of the lifting head with the nail. The forward vector 21 is pushing strongly against the nail 31 , which has the disadvantage of possibly digging into the nail or even cutting through it. Another disadvantage is that the emergence of two vectors happens instantly upon contact with the nail and the user must instantly supply the extra force for vector 21 , which means that the user feels a large shock force upon encountering the nail.
FIG. 3 b shows an aspect of the present invention, where the sideways vector 22 is very small at the moment of first contact, and so is the forward vector 23 . The side of the lifting head surface 32 is sliding almost tangentially against the nail 33 , with little resistance. The user feels almost no shock force and the forward vector 23 is almost undiminished as the tool continues to advance smoothly. As the nail moves along the curve and takes the position of nail 34 , the sideways vector 24 grows and the sideways movement accelerates. There is little or no shock force felt by the user, because vector 25 increases gradually. Of course, there is a shock when the nail 34 settles at the end of the slot and movement stops, but by that time the various sources of friction, namely the lifting head sliding over the roof and under the shingle and against the nail, have gradually lowered the speed of the tool and the shock of stopping when the nail reaches the end is not large.
Although the holes have been described as round, which is a shape easily made, the invention would also achieve the intended benefits if the holes were to have some ellipticity.
The slots in the lifting head will lift nails in a wide range of sizes. The fingers that define the slots will lift staples.
FIG. 1 shows that the top surface of the lifting head has a number of ridges 17 , 18 . As with all aspects of the lifting head, the ridges are symmetrical about the centre line passing through the handle mounting boss 3 and midway between the side tips 6 , 7 . These ridges not only strengthen the lifting head for its nail-pulling purpose, but lift the shingle from the roof and begin to direct it upwards sliding over the handle, in a camming manner.
On each side of the lifting head, on a line passing through the handle mounting position, there is a horn 19 that projects to a distance a little greater than the maximum width of the lifting head. This is useful for striking with a hammer, or kicking, to force the lifting head under particularly resistant shingles. The horns 19 curve up away from the surface on which the lifting head is resting, so that the lifting head can be rocked sideways as part of the nail extraction without a horn 19 becoming a fulcrum.
FIG. 1 shows that the rear portion 2 resembles the front portion 1 , but is smaller. The sides, and the envelope of the leading edge, of the rear portion 2 are curved for the same reason as in the front portion 1 . The construction with ridges is similar. The slots are made of overlapping round holes, with one exception that is optional. The central slot 14 is large enough for a large nail or spike, such as may be encountered sometimes in the course of removing shingles or flooring or siding or any material that was generally attached with smaller nails for which this lifting head as a whole is adapted. Such large nails usually require a claw hammer or pry bar, but if this tool is at hand, slot 14 is convenient for occasional use.
Another optional feature in FIG. 1 is a hole 9 that has a large end and a small end. The head of a nail will pass through the large end, and the tool can then be pulled so the shaft of the nail is passing through the small end. When the tool is rocked or lifted the small end will press on the head of the nail and extract the nail. This is especially useful for large nails that are occasionally encountered, or particularly stubborn nails that would rather bend than move when pried on by the slots at the leading edge of the lifting head.
FIG. 4 shows another important aspect of the invention, the convexity of the bottom surface 40 . The bottom surface of the lifting head is a section of a cylinder. It may be an elliptical cylinder. The radius of curvature may be the same for the entire bottom surface of combined front portion 1 and rear portion 2 , as illustrated, or may change at some point, most likely below the handle mounting position, so that there is a smaller radius of curvature in the rear portion 2 . In that case, the bottom surface would be sections of two cylinders. The leading edge 42 and the rear edge 41 must be thin enough to reach under a nail head while slightly compressing a shingle through which the nail passes. The thinness is achieved by the convergence of the semi-cylindrical bottom surface 40 with the top surface, and the top surface may optionally be thinned as it approaches the leading edge 42 and rear edge 41 .
As the lifting head is rocked to the rear, the bottom surface will be in constant tangential contact with the roof. The point of contact with the roof, the fulcrum, will shift on the roof in the direction towards the rear edge 41 of the lifting head, as the front end 42 rises and brings with it a nail and a shingle. It is advantageous to make such rocking contact, rather than, as in the prior art, having a sharp ridge where two planes of the bottom surface meet at a small dihedral angle. A ridge can dig into the roof surface and cause damage, whereas the convex rocking surface causes no damage. Another advantage is that the rocking motion is smooth through a large angle of the handle, until the point of contact (the fulcrum) reaches the rear edge 41 of the lifting head. In practice, it is often not necessary for the fulcrum to reach the rear edge 41 , as the shingles and nails have been pried from the roof before then. In contrast, the prior art has two types of bottom surfaces—either flat all over, or several flat planes. The fully flat prior tools use the rear edge as the fulcrum for leverage. The multi-plane prior tools use a transverse ridge as a first fulcrum, and then come to another intersecting plane so that the leverage abruptly shifts to the rear edge as the second fulcrum. Some versions have two fulcrum ridges before reaching the rear edge as a fulcrum. The shift of fulcrums subjects the user to an uncomfortable and tiring jerk in every removal. In other words, the prior art for roofing tools has either one fulcrum, that being the rear edge, or two fulcrums, being a ridge near the middle and the rear edge, or rarely three fulcrums of which the last is the rear edge. The convex surface of the present invention has an infinite number of fulcrums. The convex surface is functionally similar to the curved side of a claw hammer, which invariably is a curve not a plane, perhaps with changing curvature but without a ridge where there is a dihedral angle between planes.
FIG. 4 also shows features discussed in connection with FIG. 1 , a couple of ridges 17 , 18 , and one of the horns 19 projecting out of the page. The ridge 18 , which is closer to the centre line than ridge 17 , is higher than ridge 17 . This is an aspect of the overall roundedness of the lifting head. The shingle that is being lifted will usually be attached to the roof in at least the forward direction and one side direction. When it is lifted, the shingle curves down in all directions from the lift point, which is on the centreline of the lifting head. The shingle could be described as having a bubble formed in it. The lifting head disclosed here conforms approximately to the bubble shape, which has the beneficial effect or reduced resistance to advancing the bubble, and less cutting and breaking of the shingle.
The top surface of each of the ridges 17 , 18 is preferably concave upwards, to cammingly move the shingles upwards. It is known in the prior art to have one or two camming elements, which may or may not also serve as strengthening gussets, but a larger number, at least 4, of camming elements provides better lifting and dispersal of the shingles. A single gusset tends to slice the shingles without forcing them upwards, so then the leading edge of the shingles strikes the hosel and stalls progress. A triangular gusset would have a greater tendency than a curved ridge to slice the shingles, because the curved arc makes a gradual attack on the shingle, and benefits further from having a rounded top of the ridge all along the ridge.
FIG. 4 shows a handle 43 attached to the handle mounting boss 3 . The lifting head is most effectively manufactured by hot forging, although the invention is not limited to forged heads. Forging cannot produce a hole suitable for a handle, so a metal handle would typically be attached by a weld 44 to the lifting head. Alternatively a metal hosel could be attached to the handle mounting boss 3 by a weld 44 , and the hosel would stand in the position 43 in the figure. The hosel could be fitted with a handle of wood, fibreglass, or any material suitable for a tool handle.
Forging is not well suited to producing thin portions of the forged article, as required at the leading edge and typically at the rear edge of the lifting head. To obtain the desired thinness of the leading and rear edges, it is generally desirable to finish the bottom surface with a grinding operation. Grinding is well suited to producing a slightly convex surface, tapering to a thin edge comparable to the edge of a dull knife. The slots, in the pattern of a series of overlapping round holes, and any complete holes, will typically be formed by a hot trimming press while the lifting head is still ductile and softened from the hot forging process.
FIG. 5 shows the tool with a handle 51 . The handle 51 , if it is metal, will be welded to the handle mounting boss 3 . Alternatively, if the handle mounting boss 3 is fitted with a hosel (not shown) that is a few inches long, a handle can be inserted in the hosel. Such a handle may be made of wood, fibreglass, steel, or any material known to be suitable for tool handles. The preferred shape of the handle has a bend 52 at about two-thirds of the distance towards the end 53 . That ensures that the end 53 of the handle will touch the roof, in an extreme prying operation, before the user's hand which is near the bend 52 would touch the roof, thus protecting the hand.
Many modifications and variations besides those mentioned herein may be made in the techniques and structures described and depicted herein, resulting in other embodiments of the present invention without departing from the concept of the present invention. The foregoing disclosures should not be construed in any limited sense other than the limits of the claims that follow. Thus the scope of the invention should be determined by the appended claims and their legal equivalents rather than by the examples given. | The invention is a tool for lifting building materials, such as shingles, while extracting nails that fastened those materials. The slots that grip the nails are a concatenation of overlapping holes, for smooth insertion of the tool past the nails, and the envelope of the tool is a surface of curves for smooth insertion of the tool under the building materials. The bottom surface is a rocker that provides a moving fulcrum for prying out the nail, giving maximum force when the nail is first gripped and smoothly moving to maximum speed of extraction as the fulcrum moves back towards the user. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to the field of antimicrobial formulations, and more specifically, to an antimicrobial formulation comprising zinc pyrithione.
BACKGROUND OF THE INVENTION
[0002] Polyvalent metal salts of pyrithione (commonly known as 1-hydroxy-2-pyridinethione; 2-pyridinethiol-1-oxide; 2-pyridinethione; 2-mercaptopyridine-N-oxide; pyridinethione; and pyridinethione-N-oxide) are known to be effective antimicrobial agents and are widely used as fungicides and bactericides in products such as antifouling paints and sealants, building products, plastics and goods made therefrom, polyurethane products, textiles, cosmetics, and in anti-dandruff shampoos.
[0003] The polyvalent metal salts of pyrithione are only sparingly soluble in water and include magnesium pyrithione, strontium pyrithione, barium pyrithione, copper pyrithione, zinc pyrithione, zirconium pyrithione, cadmium pyrithione, and bismuth pyrithione. The most widely used divalent pyrithione salts are zinc pyrithione and copper pyrithione.
[0004] Zinc pyrithione effective is insoluble in water (8 ppm at neutral pH) and sparingly soluble in most organic solvents. Useful organic solvents include alcohols (e.g. methanol, ethanol), amines (e.g. diethanolamine), ether, esters, and the like.
[0005] Even in such systems, however, zinc pyrithione is poorly maintained as a dispersion and readily precipitates. In most industrial applications, therefore, the composition must be agitated, harsh solvents must be used, and/or additional compounds employed to prevent settling. Agitation complicates the manufacturing process and, in some instances, is incompatible or impracticable. Some solvents and surfactant compounds pose complications as human health and environmental hazards, and they also may interfere with the materials into which the final product is composed.
DETAILED DESCRIPTION
[0006] As used herein, the terms “microbe” or “microbial” should be interpreted to refer to any of the microscopic organisms studied by microbiologists or found in the use environment of a treated article. Such organisms include, but are not limited to, bacteria and fungi as well as other single-celled organisms such as mold, mildew and algae. Viral particles and other infectious agents are also included in the term microbe.
[0007] “Antimicrobial” further should be understood to encompass both microbicidal and microbistatic properties. That is, the term comprehends microbe killing, leading to a reduction in number of microbes, as well as a retarding effect of microbial growth, wherein numbers may remain more or less constant (but nonetheless allowing for slight increase/decrease).
[0008] For ease of discussion, this description uses the term antimicrobial to denote a broad spectrum activity (e.g. against bacteria and fungi). When speaking of efficacy against a particular microorganism or taxonomic rank, the more focused term will be used (e.g. antifungal to denote efficacy against fungal growth in particular).
[0009] Using the above example, it should be understood that efficacy against fungi does not in any way preclude the possibility that the same antimicrobial composition may demonstrate efficacy against another class of microbes.
[0010] For example, discussion of the strong bacterial efficacy demonstrated by a disclosed embodiment should not be read to exclude that embodiment from also demonstrating antifungal activity. This method of presentation should not be interpreted as limiting the scope of the invention in any way.
[0011] In an exemplary embodiment, an antimicrobial composition is manufactured, comprising zinc pyrithione, dipropylene glycol, and a polyethylene glycol distearate (e.g. Rewopol PEG 6000DS (Goldschmidt Rewo GmbH, Steinau an der Strasse, Germany)).
[0012] As one method to produce a 1000 gram batch, by way of example, 740 g dipropylene glycol is added to a mixing vessel and gently warmed with agitation to 60° C. To this DPG is added 10 g polyethylene glycol distearate, optionally with gentle agitation, to dissolve it and form a pre-mixture.
[0013] 250 grams of zinc pyrithione then is added, with brisk agitation to ensure a good dispersion. The heat source is removed and agitation discontinued as the batch is allowed to cool to standard temperature (i.e., 25° C.). The antimicrobial composition thus formed has advantageous properties over conventional dispersed zinc pyrithione formulations.
Example 1
Physical Properties
[0014] During cooling in the above method, the antimicrobial composition gelates, acquiring a viscous, gelatinous consistency. Zinc pyrithione advantageously was observed to remain dispersed in the composition, rather than settling out as is commonly seen in conventional zinc pyrithione dispersions.
[0015] Viscosity of the above exemplary composition at room temperature (25° C.) was in the range of 2480-2820 centipoise (viscosity rose over 5 min time period).
[0016] The formulation recipe can be altered without deleterious effect on the properties of the antimicrobial composition. For example, the relative amount of pyrithione in the composition can be reduced to 125 grams and that of polyethylene glycol distearate compensatorily adjusted upward to a value in the range of >10 grams to <20 grams.
[0017] Similarly, the viscosity of the present composition can be altered by controlling the relative amounts of polyethylene glycol distearate and/or polyvalent metal salt of a pyrithione therein.
[0018] When 500 grams of zinc pyrithione and no polyethylene glycol distearate was added to 500 grams of dipropylene glycol in accordance with the above-discussed method, the resulting composition possessed a high thickness and did not flow.
[0019] Conversely, a composition manufactured with 125 grams of zinc pyrithione and no polyethylene glycol distearate had a viscosity of approximately 205 cP. When the same amount of zinc pyrithione was added but 5 grams of polyethylene glycol distearate also was employed, an elevated viscosity of about 685 cP was observed in the finished composition.
[0020] Having set forth the basic parameters of the present antimicrobial composition, one of ordinary skill in the art should be able to vary the amounts of the polyvalent metal salt of a pyrithione, polyethylene glycol distearate, or both as desired to achieve a selected composition viscosity.
[0021] Surprisingly, the composition was observed to remain in a gelatinous state, even if the container housing the composition was casually handled (such as during transport or movement within a facility).
[0022] Upon simple industrial agitation, however, the composition lost its gel-like viscosity and became easily flowable, facilitating its use in conventional manufacturing processes. The zinc pyrithione again was seen to remain dispersed after de-gelating agitation.
[0023] Unexpectedly, it was observed that the agitated (de-gelated) composition did not re-gelate when agitation was ceased. Rather, the composition remained in the flowable liquid state that was attained after post-manufacture agitation.
[0024] Equally unexpectedly, no settling of the zinc pyrithione was observed in the flowable composition after manufacture and de-gelation. This property is advantageous in manufacturing, removing the need for constant or intermittent agitation as is necessary with traditional dispersion formulations.
[0025] The composition as hereinabove described was used in the production of polyurethane foam samples to assess incorporation, integrity of the polymer, and antimicrobial efficacy. Polyurethane foam is a commonly used material in shoe insoles, an application wherein bacterial and fungal contamination are problematic.
[0026] To assess successful incorporation of antimicrobial agent into the polyurethane foam, a series of shoe insole samples were manufactured and assayed.
[0027] Upon manual and visual inspection, the sample outsoles had an outward appearance no different from untreated shoe insoles. Likewise, there was no overt difference in the feel, pliancy or odor of the experimental insoles as compared to untreated controls.
[0000]
TABLE 1
Sample
Analytical (ppm)
#1 - Green
88
#2 - Black
61
#3 - Green
590
#4 - Black
67
#5 - Green
450
#6 - Green (thin)
510
#7 - Green
830
[0000]
TABLE 1a
Sample Description
Zn Response Intensity cps/μA
Untreated Controls
0 (None Detected)
0.4% Composition
0.13
0.8% Composition
0.27
[0028] Chemical analysis was undertaken to determine if the employment of the present antimicrobial composition resulted in successful incorporation of antimicrobially active agent in the finished polyurethane substrate. Foam samples were digested and zinc extracted therefrom.
Example 2
Antimicrobial Efficacy
[0029] The zinc pyrithione formulation disclosed herein possesses tremendous versatility in both polyurethane (PU) (foam and non-foamed varieties) and polyvinyl chloride (PVC) applications. For the PU applications, it affords a rapid way to introduce zinc pyrithione, itself a chemical very difficult to formulate and disperse, into cross linked liquid systems. It does not appear to affect the PU cross-linking process, which is well known to be very sensitive to water.
[0030] In order to evaluate Microban Experimental Product Z01-S4205-250 for use as an antimicrobial in polymer systems, a polyurethane foam (such as commonly used in shoe liners) was chosen for testing. Manufactured for evaluation were a number of samples, in which polyurethane foam was treated with the disclosed zinc pyrithione formulation and incorporated into a foam such as used in shoe insoles. Multiple samples of the additive were employed, made from different batches to further ensure reproducibility in making the disclosed formulation.
[0031] The PU foam samples were tested using the below-described industry standard procedures (detailed description of methods available upon request).
[0032] The AATCC Test Method 90 qualitatively determines the presence of antimicrobial activity in antimicrobial products capable of producing a zone of inhibition but lacking sufficiently flat surfaces to meet the sample requirements for typical zone of inhibition testing. Test materials of this type are partially embedded in inoculated agar to provide full surface contact with the media.
[0033] Staphylococcus aureus ATCC 6538 and Klebsiella pneumoniae ATCC 4352 typically are selected as surrogates for Gram-positive and Gram-negative bacteria, respectively.
[0034] Ideally, a sample should provide a surface area of approximately 400 to 600 mm square for contact with the inoculated media. One milliliter of each challenge organism in Trypicase Soy Broth is pipetted into separate 150 ml portions of sterile, molten Mueller-Hinton Agar maintained in a water bath at a temperature no warmer than 45° C.
[0035] For each organism, a separate 100 mm×15 mm Petri dish is filled with inoculated agar so as to create a 3 millimeter layer (i.e., about 10 ml). The agar is allowed to cool to a semi-gelatinous state, then the sample is gently pressed into the agar.
[0036] An additional amount of inoculated agar containing the same organism is poured into the plate to achieve a total depth of approximately 6 mm and only partially embed the sample.
[0037] The plate is then covered, the agar hardened, and then incubated at 37° C. for 18-24 hours.
[0038] Foam polyurethane insole samples from two batches were tested according to this protocol. Results are shown in Table 2.
[0000]
TABLE 2
Sample
TM90 Kp
TM90 Sa
#1 - Green
No zone
No zone
#2 - Black
No zone
No zone
#3 - Green
Zone
Zone
#4 - Black
No zone
No zone
#5 - Green
Zone
Zone
#6 - Green (thin)
Zone
Zone
#7 - Green
Zone
Zone
[0039] Further testing was in accordance with a modified JIS Z2801:2000 test protocol (available from Japanese Industrial Standards Committee, Tokyo, Japan). The Z2801 protocol is an internationally known standard test to assess quantitative antimicrobial activity and efficacy. The protocol and specific modifications made thereto are briefly summarized below.
[0040] The comparison test for antimicrobial efficacy used Klebsiella pneumoniae , ATCC 4352. The test organism was grown, and a portion of an exponentially growing culture was collected into Japanese Nutrient Broth or Brain-Heart Infusion Broth. An inoculum was prepared at about 10 7 colony-forming units (CFU) per milliliter by dilution with relevant broth.
[0041] Sample pieces were targeted to weigh approximately 1.0±0.2 grams. Sample test pieces were reduced to approximately 38 mm×38 mm dimensions (or as close to these dimensions as practical).
[0042] A sample was placed on moistened laboratory tissue in a culture plate, and 1.0 ml of test inoculum (10 7 CFU) was pipetted onto the sample surface. A cover slip or film was placed over and in contact with the inoculum to ensure uniform and substantially complete coverage of the inoculum over the sample surface. The culture plate then was incubated for 24 hours at 37° with humidity.
[0043] In parallel and for each inoculum used, 1.0 ml of the inoculum was added to 99±0.1 ml of neutralizer broth, then mixed and plated in 1.0 ml of a 1/10 saline dilution in duplicate. This is done to precisely establish the concentration of the each test organism in its inoculum.
[0044] The applied liquids on the plates were allowed to dry, then the plates were inverted and incubated for 18 to 24 hours. Following incubation, the CFU on each plate were enumerated and, taking into account the dilution made, the average number of CFU applied in 1.0 ml of the inoculum calculated and recorded.
[0045] Bacteria on the sample and cover slip/film were recovered, collected into D/E Neutralizing Broth, and counted. The antimicrobial activity of the test samples is expressed herein as a log reduction value in comparison with the bacterial growth of the corresponding untreated (control) sample.
[0046] Samples—negative control and experimental additive samples 1-2—were run in duplicate, with the averaged results presented in TABLE 3.
[0047] Using the values previously calculated and reported for each test organism at a given time interval for each test sample, the percent reduction versus the inoculum was calculated using the following equation:
[0000] [( A−B )/ A ]×100=Percent Reduction vs. Inoculum
[0048] where A=the average CFU of the test organism per 1 ml of inoculum added directly to the neutralizer solution without exposure to the sample, and B=the average value of the test organism recovered from each sample test piece.
[0049] The log (base 10) reduction was calculated for the ratio of the surviving organisms on the test sample versus the inoculum using the following equation:
[0000] log ( C/B )=Log Reduction of Organisms on Test Sample vs. Untreated Control
[0050] where: C=the average cfu of the test organism recovered in the neutralizer-inoculum mixture after the specified contact time with the untreated control.
[0051] The AATCC Test Method 30(III) assay qualitatively evaluates the antifungal efficacy of products containing antimicrobial additives through the use of a single surrogate organism. This test utilizes Aspergillus niger , ATTC 6275, as a surrogate for a number of common fungi. The assay proceeds along these general lines:
[0052] 1. Duplicate test pieces are made from the treated material and untreated control material, each piece approximately 1 to 1.5 inches on a side.
[0053] 2. A fungal inoculum is prepared by adding scrapings from a ripe fruiting culture of Aspergillus niger to 50±1 ml of normal saline. Glass beads are placed therein and the flask shaken to liberate and suspend of the spores.
[0054] 3. In a modification to the international standard test method, 1.0 ml sterile 0.05% aqueous solution of Triton X (a non-ionic surfactant) is added to each sample and blotted with an aseptic wiper prior to inoculation. Using a sterile glass pipette, 1.0±0.1 ml of the prepared inoculum is evenly distributed over the surface of each of four Petri dishes containing solidified Sabouraud Dextrose Agar.
[0055] 4. A test piece or control piece is placed on the agar surface in the dish, over which is evenly distributed 0.2±0.0 ml. The sample then is covered and incubated at 28°±1° C. for 7 days.
[0056] 5. After incubation, the surface of each test piece is visually examined to determine the percentage of surface area covered by the black fungus, Aspergillus niger . Growth is rated using the following rating system:
“0”—Sample exhibits strong antifungal activity A sample earning this rating shall be totally free of fungal growth on the test surface and may exhibit a zone of inhibition against the test organisms applied to the nutritive agar on which the sample is placed. Observations of this type are common to materials treated with appropriate levels of antifungal agents. “1”—Sample is not supportive of fungal growth A sample earning this rating shall exhibit only irregular, unhealthy fungal infestation on the test surface as evidenced by discontinuous fungal mat and the appearance of stressed or weakened sporangiophores. “2”—Sample is susceptible to fungal growth A sample earning this rating shall exhibit regular, healthy fungal infestation on the test surface comparable to that on the nutritive agar surrounding the sample. The rating should include a percent estimate of the total surface so infested.
[0063] 6. If a zone of inhibition is present on the plate, its width is calculated (using the following equation) and reported along with the rating score.
[0000] W =( T−D )/2
[0000] where W is the width of clear zone of inhibition (mm); T is the total diameter of test specimen and clear zone (mm); and D is the diameter of the test specimen (mm).
[0064] As is clear, three of the samples did not pass the bacterial tests: both black samples and the first green sample. None of the samples showed any signs of fungal growth after the 7-day TM30(III) test; however, the samples are visually analyzed and on the black samples, it is possible that there may have been microscopic growth that was missed by the microbiologist (perhaps due to the lack of contrast—the fungus is as black as the sample material).
[0065] The polyurethane foam itself generally is not a fungus-friendly substrate, although some of the previous controls have shown macroscopic fungal growth. This is presumed to be because the TM30(III) protocol adds some nutrients to the system to mimic the oils and skin cells that would collect over time on a shoe insole. The first sample further showed traces of arsenic in an EDX scan; the presence of arsenic may have inhibited the fungal growth to some degree on this sample.
[0000]
TABLE 3
Sample
JIS Z 2801 Kp
JIS Z 2801 Sa
#1 - Green
NR
NR
#2 - Black
NR
NR
#3 - Green
99.9%
99.9%
#4 - Black
NR
NR
#5 - Green
99.9%
99.9%
#6 - Green (thin)
99.9%
99.9%
#7 - Green
99.9%
99.9%
[0000]
TABLE 3a
Log
Recovery
Reduction
Log Reduction
Sample Description
(CFU)
v. control
v. inoculum
Control 1 + Control Average
1450
-baseline-
-NA-
0.4% Set 2 Additive Sample 1
<100
>1.16
>3.22
0.4% Set 2 Additive Sample 2
<100
>1.16
>3.22
0.4% Set 6 Additive Sample 1
<100
>1.16
>3.22
0.4% Set 6 Additive Sample 2
<100
>1.16
>3.22
0.4% Set 10 Additive Sample 1
<100
>1.16
>3.22
0.4% Set 10 Additive Sample 2
<100
>1.16
>3.22
0.8% Set 2 Additive Sample 1
<100
>1.16
>3.22
0.8% Set 2 Additive Sample 2
<100
>1.16
>3.22
0.8% Set 6 Additive Sample 1
<100
>1.16
>3.22
0.8% Set 6 Additive Sample 2
<100
>1.16
>3.22
0.8% Set 10 Additive Sample 1
<100
>1.16
>3.22
0.8% Set 10 Additive Sample 2
<100
>1.16
>3.22
[0066] Taking the analytical results into account, these data clearly demonstrate that samples have been treated with the antimicrobial composition disclosed herein are strongly efficacious against bacteria and fungi.
[0067] All materials treated with the zinc pyrithione composition disclosed herein passed all antibacterial and antifungal test procedures. The materials without the disclosed composition all failed the antibacterial tests. It is bacteria that generally cause the odor issues in shoe applications.
[0000]
TABLE 4
Sample
TM30(iii) A/B
#1 - Green
0/0
#2 - Black
0/0
#3 - Green
0/0
#4 - Black
0/0
#5 - Green
0/0
#6 - Green (thin)
0/0
#7 - Green
0/0
[0000]
TABLE 4a
Sample Description
Rating
Comments
Control 1 + Control Average
1
Growth on side
0.4% Set 2 Additive Sample 1
2
Growth on side,
some on the top
0.4% Set 2 Additive Sample 2
0
Very clean, no growth
0.4% Set 6 Additive Sample 1
0
Very clean, no growth
0.4% Set 6 Additive Sample 2
0
Very clean, no growth
0.4% Set 10 Additive Sample 1
0
Very clean, no growth
0.4% Set 10 Additive Sample 2
0
Very clean, no growth
0.8% Set 2 Additive Sample 1
0
Very clean, no growth
0.8% Set 2 Additive Sample 2
0
Very clean, no growth
0.8% Set 6 Additive Sample 1
0
Very clean, no growth
0.8% Set 6 Additive Sample 2
0
Very clean, no growth
0.8% Set 10 Additive Sample 1
0
Very clean, no growth
0.8% Set 10 Additive Sample 2
0
Very clean, no growth
[0068] Data further demonstrate that the antimicrobial composition and its manufacturing method do not perturb the antimicrobial properties of the antimicrobial active agent (in the above examples, zinc pyrithione) and that the composition is readily compatible with polymeric substrates such as, without limitation, polyurethane foam; flexible polyvinyl chloride; glues, binders and adhesives; rubbers; and latexes.
[0069] It will therefore be readily understood by those persons skilled in the art that the present composition and methods are susceptible of broad utility and application. Many embodiments and adaptations other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested to one of ordinary skill by the present disclosure and the foregoing description thereof, without departing from the substance or scope thereof.
[0070] Accordingly, while the present composition and methods have been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary and is made merely for purposes of providing a full and enabling disclosure.
[0071] The foregoing disclosure is not intended or to be construed to limit or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements. | The present invention relates to the field of antimicrobial formulations, and more specifically, to an antimicrobial formulation comprising zinc pyrithione in a stabilized dispersion. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application no. PCT/EP2005/050074, filed Jan. 10, 2005, which claims the priority of European application no. 04100391.4, Feb. 4, 2004, and which application no. PCT/EP2005/050074 claims the priority of European application no. 04100392.2, filed Feb. 4, 2004, and each of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a wire for external exposure. The wire has a steel core and a double metal coating. The present invention also relates to various uses of such a wire and to a method of manufacturing such a wire.
BACKGROUND OF THE INVENTION
The prior art has provided a steel wire with various metallic coatings in order to add functionalities to the steel wire or in order to enhance its properties. Known metallic coatings on a steel wire are brass for adhesion with rubber, zinc or a zinc-aluminum alloy for corrosion resistance, nickel for a heat resistance.
Zinc coatings are often applied to the steel wire by means of a hot dip process for reasons of economy. Having regard to the time the steel wire is in the zinc bath and to the temperature of the zinc bath, a Fe—Zn interlayer is formed between the steel core and the zinc coating. This interlayer is brittle. Fe—Zn interlayer particles may be spread throughout the zinc coating during further drawing. Due to cracking of the Fe—Zn, sharp crevices are created which are subsequently filled with zinc. This surface damage makes the roughness of the steel wire greater and corrosion of the Fe—Zn interlayer particles at the wire surface leads very fast to red dust spots. Zinc aluminum coatings may have the drawback that the Fe—Al inter-metallic coating grows too fast and is too brittle. The consequence may be the presence of broken particles in the zinc aluminum coating and a fragmentation of the Fe—Al inter-metallic coating.
A nickel coating as such may offer various advantages such as heat resistance, but has the drawback that it deforms not easily and that it may be damaged easily. Hence its processing is difficult and not economical.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to avoid the drawbacks of the prior art.
It is also an object of the present invention to increase the corrosion resistance of steel wires.
It is yet another and particular object of the present invention to provide steel wires with a barrier against hydrogen.
According to a first aspect of the present invention, there is provided a wire for external exposure. The terms “wire for external exposure” typically refer to wires adapted for use either outside any matrix of softer material or inside a matrix of softer material but without any chemical bond between the wire and the matrix material. The wire has a steel core, a nickel sub-coating and a zinc or zinc alloy top coating above the nickel sub-coating. It will be noted that the terms “weight percent” and “percentage by weight” will be referred to as “percent” for brevity throughout. The steel is a high-carbon steel comprising more than 0.20 percent carbon, e.g. more than 0.35 percent, e.g. more than 0.50 percent. The steel is preferably a pearlitic steel. Martensitic or bainitic steels, however, are not excluded.
The nickel sub-coating may have varying thicknesses. However, the greater the thickness of the nickel sub-coating, the better the barrier function of the nickel sub-coating. The thickness of the nickel sub-coating may vary between 0.3 μm and more than 10 μm.
A 0.3 μm nickel sub-coating corresponds to about 2.665 g/m 2 , a 1 μm nickel sub-coating corresponds to about 8.85 g/m 2 , a 2 μm nickel layer corresponds to about 17.70 g/m 2 , a 5 μm nickel sub-coating to about 44.25 g/m 2 and a 10 μm nickel sub-coating corresponds to about 88 g/m 2 .
The function of the nickel sub coating as a “barrier” for hydrogen may be explained as follows. Nickel is supposed to absorb the hydrogen. The absorbed hydrogen in the nickel forms a particular layer which obstructs electrical currents.
In the past attempts were done with amorphous steel cord for rubber reinforcement. The amorphous steel filaments had a nickel sub-coating of less than 1.0 μm and a top coating of zinc. The amorphous steel filaments were twisted into a steel cord and this steel cord was embedded in rubber with chemical adhesion between the steel cord and the rubber. The typical steel cord tests carried out, showed hardly any advantages or differences for these amorphous steel filaments with a nickel sub-coating and a zinc top-coating in comparison with similar steel cord filaments coated with zinc alone.
The invention wire can have a round cross-section or a non-round cross-section such as flattened, rectangular, square, zeta, and so forth.
The steel core coated with both nickel and zinc is further drawn or rolled to its final cross-section in a final work-hardened state. In other terms the steel wire is in a final drawn or rolled work-hardened state. The coatings steps are not the last steps performed on the steel core. By applying a top coating of zinc or a zinc alloy on top of the nickel sub coating, the nickel sub coating is not subjected directly to the work hardening of drawing or rolling. Zinc is now known as being better deformable than nickel, so that the deformation process occurs with the same comfort as the deformation of steel wires with only zinc or zinc alloy coating layers. In this way the invention both profits from the presence of nickel in the sub coating and from the easy deformability of zinc in the top coating.
Depending upon the typical way of manufacturing and of providing the coatings, a wire according to the invention may have following subsequent layers:
i) a steel core; ii) a Fe—Ni alloy interlayer; this is the case if the nickel coated steel wire is subjected to a heat treatment, e.g. by going through a zinc bath; experience and tests have shown that this Fe—Ni alloy interlayer is only present if the time period for the heat treatment is sufficiently long; iii) a nickel (Ni) sub-coating; iv) a Ni—Zn alloy interlayer; this is the case if the zinc top coating is applied via a hot dip process; this Ni—Zn alloy interlayer may provide a good resistance against corrosion in aggressive environments (such as simulated in salt spray tests); v) a zinc or zinc alloy top coating.
If of a sufficient thickness the nickel sub-coating may form a closed layer and prevent a brittle Fe—Zn alloy layer from being formed or prevent brittle Fe—Zn inter-metallics from being present. As a consequence, the invention wire does not have the drawbacks associated with the brittle Fe—Zn alloy layer.
The top-coating of zinc or zinc alloy may be thicker or thinner than the nickel sub-coating.
The top coating may be pure zinc or may be a zinc alloy such as a zinc aluminum alloy comprising between 0.5% and 10% aluminum, e.g. between 1.0% and 8% aluminum, e.g. about 5% aluminum. A Mischmetal such as La or Ce may be present in amounts of about 0.02%.
In a particular embodiment of the first aspect of the present invention, the invention wire comprises chromium which is present in or in contact with the nickel sub-coating. The chromium is present in the form of metallic Cr or in the form of the ion Cr 3+ .
According to a second aspect of the present invention, the invention wire is suitable for various uses or applications where the invention wire has no chemical bond with a surrounding matrix. It particularly concerns applications where hydrogen embrittlement may be a problem. These applications are preferably off-shore applications.
As a first application, a non-bonded flexible pipe may comprise one or more invention wires. The term “non-bonded” refers to wires which are only mechanically anchored and where chemical adhesion is mainly absent. An electrolytic coating of nickel, if of sufficient thickness, provides an excellent barrier against hydrogen and thus avoids, or at least slows down, hydrogen embrittlement. The invention wires for reinforcement in non-bonded flexible pipes may have a round or a non-round cross-section. The non-round cross-section may be a flattened wire, a rectangular wire, a zeta wire etc. . . .
As a second application, a tow leader cable comprises one or more invention wires.
As a third application, a control cable comprises one or more invention wires.
According to a third aspect of the present invention, there is provided a method of manufacturing a wire. The method comprises the steps of:
a) providing a steel core with a carbon content above 0.20 percent; b) coating the steel core with a nickel sub-coating; c) coating a zinc or zinc alloy top coating on top of the nickel sub-coating; d) drawing or rolling the wire with the nickel sub-coating and the zinc or zinc alloy top coating to a final cross-section.
The nickel sub-coating is preferably applied on the steel core by means of an electrolytic method. Electroless deposition methods or vacuum plating of nickel are not excluded.
The zinc or zinc alloy top coating is preferably applied by means of a hot dip bath. Other ways of applying the zinc or zinc alloy top coating are not excluded: e.g. in an electrolytic way. The hot dip method has as consequence that a zinc-nickel interlayer is formed and possibly also an iron-nickel interlayer. This is due to the heating of the wire during the passing through the zinc bath.
As already mentioned, due to the fact that the zinc or zinc alloy forms the top coating, the relatively undeformable nickel sub layer is not subject to the drawing or rolling treatment.
In a particular embodiment of the invention, the method of manufacturing an invention wire comprises a further step of:
e) guiding the wire in a bath of Cr 3+ -salts.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described into more detail with reference to the accompanying drawings wherein
FIG. 1 shows a cross-section of an invention wire
FIG. 2 shows part of a cross-section of a non-bonded flexible pipe.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a cross-section of an invention steel wire 10 . The invention has a pearlitic high-carbon steel core 12 with a carbon content above 0.60%. The steel core 12 has been coated with a nickel sub-coating 14 in an electrolytic way and, on above the nickel sub-coating, with a zinc top-coating 16 by means of a hot dip process.
Going into more detail with the help of the part of FIG. 1 which has been enlarged, the invention wire comprises following different metallic structures:
a steel core 12 ; possibly an Fe—Ni alloy interlayer 18 ; a nickel sub-coating 14 of at least 2 μm; a Ni—Zn alloy interlayer 20 ; a zinc top-layer 16 .
Due to the presence of a fully closed nickel sub-coating 14 , a brittle Fe—Zn alloy interlayer and sharp Fe—Zn inter-metallic particles are not formed. This is advantageous with respect to the fatigue behavior of the invention wire 10 .
The Fe—Ni alloy interlayer 18 and the Ni—Zn alloy interlayer 20 are possibly formed during the hot dip process, during which the invention wire is heating above 400° C. during about 30 seconds. The longer the hot dip process takes, the more chance a Fe—Ni alloy interlayer 18 will be formed.
FIG. 2 shows part of a cross-section of a non-bonded flexible pipe 30 . The flexible pipe 30 has following subsequent layers starting from the radially inner layer:
a collapse resistant layer 32 ; an inner fluid barrier 34 in polymer; a hoop strength layer 36 with zeta martensitic steel wires 37 having a nickel sub-coating and a zinc top-coating; an inner anti-wear layer 38 ; an inner tensile strength layer 40 with flat martensitic steel wires 42 with a nickel sub-coating and a zinc top-coating; an outer anti-wear layer 44 ; an outer tensile strength layer 46 with with flat martensitic steel wires 47 with a nickel sub-coating and a zinc top-coating; an external fluid barrier 48 .
The nickel sub-coating functions as a barrier layer against the hydrogen sulfide ions (HS − ) which may penetrate into the several layers. Without the nickel sub-coating sulfide stress corrosion is quickly started.
EXAMPLE 1
A nickel sub-coating of 3 μm to 4 μm is plated in an electrolytic way on a carbon steel wire. A zinc top coating of about 15 μm to 25 μm is plated above the nickel sub-coating by means of a hot dip process. The thus double-coated steel wire is then drawn to a final diameter of 0.175 mm. In the final product the nickel sub-coating has a thickness of 1.0 μm and the thickness of the pure zinc top-coating is about 2 μm to 5 μm. This invention wire is compared with a prior art steel rope where the individual steel wires are only coated with zinc. A salt spray test carried out according to DIN SS 50021 and ASTM. B 117 and ISO 9227 in 10% relative humidity, at 35° C. and with 5% NaCl has provided following results.
TABLE 1
0-24
24-48
48-72
72-96
hours
hours
hours
hours
1
Spots DBR
DBR (5%)
2
Spots DBR
DBR (5%)
3
DBR (5%)
4
DBR (5%)
Sample 1 is an invention wire not treated with oil.
Sample 2 is an invention wire treated with oil.
Sample 3 is a prior art wire not treated with oil.
Sample 4 is a prior art wire treated with oil.
DBR is the abbreviation for dark brown rust.
EXAMPLE 2
Three different wires have been compared with each other:
1. a prior art wire of 0.10 mm diameter with a zinc top-coating of 2.85 μm (200 g/m 2 ); 2. an invention wire of 0.10 mm diameter with a nickel sub-coating of 0.8 μm (6.86 g/m 2 ) and a top-coating of zinc of 2.85 μm; 3. an invention wire of 0.10 mm diameter with a nickel sub-coating of 0.8 μm (6.86 g/m 2 ) and a top-coating of zinc of 2.85 μm passivated in a bath of chromium (Cr 3+ ) salts.
The corrosion resistance of the three wires has been determined by monitoring the corrosion potential of such a wire in an electrolyte of demi-water. Once the protecting zinc top-coating is corroded away, the monitored potential increases from the potential of zinc to the one of iron or the mixed potential of nickel-iron. The time needed to reach the half wave potential is measured. Table 2 summarizes the results.
TABLE 2
Test 1
Test 2
Test 3
Average
(Hours)
(Hours)
(Hours)
(Hours)
1
17.1
18.4
19.5
18.3
2
21.6
22.8
23.9
22.8
3
50.5
63.4
65.9
59.9
The invention wire 2 with the nickel sub-coating has a better corrosion resistance than a prior art wire 1.
The corrosion resistance of invention wire 3 is unexpectedly high. At present the mechanism is not yet clear. A possible explanation may be that the Cr 3+ will transform into metallic Cr-atoms and that these Cr-atoms form a small stainless steel layer with the available Fe and Ni.
EXAMPLE 3
The corrosion resistance of following wire samples has been determined by means of a salt spray test:
1. prior art high carbon steel wire with 20 μm zinc 2. prior art high carbon steel wire with 20 μm zinc aluminum alloy (5% aluminum) 3. invention high-carbon steel wire with 2 μm nickel and 18 μm zinc aluminum (5% Al) 4. invention high-carbon steel wire with 2 μm nickel and 18 μm zinc 5. invention high-carbon steel wire with 5 μm nickel and 15 μm zinc 6. invention high-carbon steel wire with 10 μm nickel and 10 μm zinc
7. invention high-carbon steel wire with 15 μm nickel and 5 μm zinc
TABLE 3
Wire sample
DRB 5%
#1
12
8
12
#2
12
8
12
#3
24
20
12
#4
24
32
24
#5
28
28
24
#6
44
32
44
#7
28
40
44
Investigation of the wire samples has revealed that the nickel coating is undamaged after wire drawing. The table shows that the more nickel is present, the better the corrosion results.
While this invention has been described as having a preferred design, it is understood that it is capable of further modifications, and uses and/or adaptations of the invention and following in general the principle of the invention and including such departures from the present disclosure as come within the known or customary practice in the art to which the invention pertains, and as may be applied to the central features hereinbefore set forth, and fall within the scope of the invention or limits of the claims appended hereto. | A wire for external exposure, i.e. without chemical binding with a polymer or rubber matrix. The wire has a steel core, a nickel sub-coating and a zinc or zinc alloy top coating above the nickel sub-coating. The steel core has a carbon content exceeding 0.20%. The wire is in a work-hardened state by drawing or rolling. The wire has an excellent corrosion resistance and provides an excellent barrier against hydrogen. Preferable uses are wires in off-shore applications. | 8 |
SUMMARY OF THE INVENTION
Starting from this method of producing a pile wall consisting of spaced, individual or clustered piles and bridging piles which are crossconnected thereto and which are intended for initially free zones which are subsequently closed by the bridging piles, the present invention is characterised in that the bridging piles are suspended from spaced piles constructed as vertical piles, being suspended from those boundary surfaces thereof which are remote from the pressure, and being locked automatically and positively against any further movement.
Accordingly, a pile wall produced by the method, is characterised by the provision of recesses in the spaced piles, which are constructed in the form of vertical piles, in conjunction with brackets which, on that side of the vertical piles which is remote from the pressure, are constructed to be movable through the recesses in the vertical pile and which form a bearing surface for the bridging piles, said bearing surface being situated on the side remote from the pressure, so that when the brackets are in the operative position they are subjected to an anti-clockwise torque.
The present invention is thus based on the finding that it is not necessary for the spaced piles to be driven into the subsoil for civil engineering purposes after the style of the sheet-piles of sheet-pile walls instead, particularly for building construction purposes, it may be quite sufficient for the said spaced piles to be constructed as vertical piles, this term being used in this context to denote any pile assuming a specific position in space irrespective of the nature of the steps maintaining these piles in their respective position to give them stability. The vertical piles can therefore be provided with baseplates which bear them, the vertical piles may be inserted, keyed or screwed into vertical pipes, if bases are used which internally match the section of the vertical piles and which are externally screwthreaded, they can be driven into the soil, they can be poured, pressed, or secured by dowels in concrete or metal block foundations, they can be held by separate bearing structural elements such as scaffolding tubes, bearers projecting beyond fixed building walls, etc, or otherwise be fixed and retained in any required position.
In development of this principle of the invention, the movement for placing and locking the bridging piles is composed of an initial lifting movement with simultaneous abutment of the bridging piles against the vertical piles, the distance between which is to be bridged, the said bridging piles abutting the said vertical piles at those boundary surfaces which are remote from the pressure, the initial movement being followed by a dropping movement on the part of the bridging pile.
Advantageously, each further pile bridging the same zone between the vertical piles is subjected to such a combined movement, disregarding the bridging of other initially free zones between verticl piles.
To enable the wall to take the pressure exerted by the liquids, such as water, or by substances of a behaviour similar to liquids, such as river sand, peat or building materials which have not yet set, such as concrete, mixtures of concrete and gravel, pasty and watery cement, plaster and other synthetic material mixtures etc., the said wall must be sealed, particularly in respect of its recesses, either by providing the pile wall with impenetrable curtains, for example polyethylene sheeting curtains, cap or plug closures for the recesses in the pile wall and/or by sealing the cross-bond between the vertical and bridging piles by means of seals disposed on and between the same, more particularly sealing strips, while in the case of sacrifice formwork iron or steel piles can be welded together for this purpose.
The further construction of a pile wall made by the method from spaced, individual or clustered piles and bridging piles which are cross-connected thereto and which are intended for initially free zones which are subsequently closed by the bridging piles, and with the provision of recesses in the spaced piles, which are constructed in the form of vertical piles, in conjunction with brackets which, on that side the vertical piles which is remote from the pressure, are constructed to be movable through the recesses in the vertical pile and which form a bearing surface for the bridging piles, said bearing surface being situated on the side remote from the pressure, so that when the brackets are in the operative position they are subjected to an anti-clockwise torque, is characterised according to the invention in that the bridging piles have a S-shaped cross-section with edge zones bent hook-fashion and another zone situated between the edge zones and hereinafter referred to as the intermediate zone for short, within which intermediate zone there is a cranked portion which is responsible for the S-shape, followed by zones which extend in plane-parallel relationship to that boundary surface of the vertical piles which is remote from the pressure.
Advantageously, the vertical pile itself has a corrugated cross-sectional shape which corresponds to the pattern of the letter "W" and which has flat zones at the places corresonding to the reversal points of the comparative letter, with the difference that the flat zones of the vertical pile section divided by the central plane of symmetry through the vertical pile section are at a distance from the edge flat zones which is approximately twice the distance of the latter from the edge flanges terminating the section. The advantage of this is that space is available on that boundary surface of the vertical pile which is adjacent the pressure, to accommodate the brackets or suspension means which may alternatively be referred to as suspension hooks because of their shape, and this means that the work is eliminated which would otherwise be required to accommodate in these surroundings, for example the soil, the bracket or suspension hook limbs projecting beyond those boundary surfaces of the vertical pile which are adjacent the pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
One exemplified embodiment of the invention is illustrated in the accompanying drawing. In this exemplified embodiment the vertical piles are constructed as driven piles.
FIG. 1 of the drawing is a plan view of a pile wall constructed according to the invention, which wall may also be termed a sheet-pile wall when sealing means (not shown), more particularly sealing strips, are provided for the joints between the bridging piles.
FIG. 2 is a horizontal section on the line II--II of FIG. 1.
FIG. 3 is a cross-section to an enlarged scale through a bridging pile according to the invention.
FIG. 4 shows a plurality of bridging piles disposed vertically one beneath the other to show more clearly the individual stages of the placing operation.
FIG. 5 is a side view of a steel bracket constructed as a suspension hook.
FIG. 6 is a front view thereof.
FIG. 7 shows the same with sealing means.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 of the drawing, reference 1 denotes the intervals between the driven piles 2, such intervals being provided because the initially free zones 3 between the driven piles 2 are to be bridged by piles 4 which are therefore referred to hereinafter as bridging piles. The advantage of spacing the driven piles 2 from one another and bridging the initially free zones which are subsequently closed by the bridging piles 4 is elimination of the locks otherwise required for the erection of closed pile walls having interlocking driven piles.
FIG. 2 of the drawing shows that the driven piles 2 have a W-shaped section, the driven piles being symmetrical with respect to a central plane 21--21. It will be apparent that a first difference from the comparative letter "W" is that flat zones 22 and 23 are provided instead of the reversal points in the comparative letter, while the second difference is that while the middle limb of the comparative letter has a relatively short height, the height 24 of the flat zone 22 from the flat zone 23 of the generally corrugated section is twice the height 25 between the flat zones 23 and the end flanges 26 which terminate the driven pile section. Since the recesses 27 which are provided in vertical rows in the flanges 26 (see FIG. 1) are intended to receive the suspension hooks 8 for the bridging piles 2 as shown in FIGS. 3 and 4, the result of the proposed construction of the driven pile section is that the limbs 81 of the suspension hooks 8 visible in the said Figures can be accommodated without difficulty because when the piles 2 having the section shown in FIG. 2 are driven, it is inevitable that there will be crumbling of the soil situated beneath the flanges 26 with reference to FIG. 2 with the result that the limbs 81 of the hooks 8 -- insofar as they project beyond the pressure-receiving boundary surface 28 of the driven pile section flanks 26 -- can pass through the recesses 27 in the crumbled surroundings, e.g. soil, as they are pressed in, without further accommodation being required.
FIGS. 3 and 4 show the section of the bridging piles 4. The top and bottom flanks of the bridging piles have edge zones 41, 42 which are bent to be hook-shaped. Extending downwardly, the curved edge zone 41 is followed by a zone 43 over which the bridging piles 4 have a wall zone which extends in plane-parallel relationship to the boundary surface 28 of the driven piles 2 bridged by the piles 4. This zone is followed by a cranked zone 44 which is again followed by a flat zone 45 which merges into the curvature 42. This construction of the bridging piles 4 enables them to be placed by bringing them into the position shown in broken lines in FIG. 3 which enables them to be moved over the limb 82 of the suspension hooks 8 which have already been engaged in the recesses 27. The flat zone 45 enables the bridging pile 4 to be slid downwards along those boundary surfaces 29 of the driven piles 2 which are remote from the pressure, the zones between the driven piles still being free and requiring to be bridged by the pile illustrated in FIG. 3. Lowering of the pile 4 from the broken-line position into the solid-line position does not entail the slightest difficulty therefore. In this position, the curved bottom edge zone 42 automatically engages in the recess 83 formed between the U-shaped limbs 81 and 82 of the suspension hooks 8. FIG. 3 clearly shows that the top curved edge zone 41 is simultaneously received in the same recess 83 and automatic locking of the bridging piles 4 in question is thus obtained both in the bottom and in the top zone.
FIG. 4 shows the general arrangement of a plurality of bridging piles which have already been placed. After the free zones between the driven piles have been closed as illustrated, the screw jacks 9 are used. These have end members 91 which are received in corresponding recesses in the flat zones 22 of the driven piles 2 (see FIG. 2), so that pits, trenches and other spaces produced by the excavation of soil and required for civil engineering purposes can be so braced by pile walls constructed according to the invention that it is impossible for soil to collapse into such spaces, so that labour is ideally protected against any danger of the walls' collapsing, or injury due to breakdown of the formwork.
FIGS. 5 and 6 show the actual steel suspension hook 8 itself. It will be apparent that the basic shape of the hook is that of the Arabic number 4, the U-shaped top part being formed by the side limbs 84 and 86 which are interconnected by the bottom limb 88 and which together define the engagement area 89 for the bridging piles 4, while the bottom surface 81, when viewed perpendicularly to that surface 21 of the driven pile (FIG. 2) which is remote from the pressure, has a depth adequate to support two inter-engaged bridging piles.
Sealing-means in the form of seals having the general reference 0 and consisting of high-elasticity materials, such as rubber or other elastomers, are provided to seal the slots 27. FIG. 7 shows a rubber plate 01 which covers the slot 27 formed in the driven pile wall 26 to receive the bracket 8, the said rubber plate covering the said slot over the entire extent of its zone not occupied by the bracket, in order to seal the slot with respect to the substance concerned and being subject to the pressure of the latter. In the middle, the rubber plate 01 is extended outwardly towards the bridging pile 4. The outwardly extending portion 011 either terminates at the dot-dash line 012 or else merges into the cap 013 which encloses the entire bracket 8, so that the same is protected completely not only against the substance concerned but also against corrosion. A co-acting sealing means in the form of a co-acting plate 02 of rubber is also provided. The limb 45 of the bridging pile 4 provides the counter-pressure for the rubber plate 02. There is not difficulty in covering the bracket 8 with the high-elasticity material of the sealing-means 01, 011, 013 and 02, particularly if lubricants such as talcum powder are used. The consistency and the excess pressure of the material which is to be sealed off will determine whether closed caps or outwardly extending portions terminating in open ends are to be preferred. In similar way there is a possibility for making tight, to seal resp. the bridging piles 4 in relation to each other. A further possibility is given by covering the bridging piles with high elasticity materials.
The invention covers not only each individual one of its indicated features -- even if it has been mentioned only in conjunction with other features -- but also each embodiable partial combination of the features, and also the total combination of all the features, insofar as individual features, partial combinations and/or the total combination are technically rational, practical and usable, even if the respective attainable novel technical effects are not mentioned and described in detail. All the discernible details mentioned in the description and/or the claims and/or illustrated in the drawing and any combinations of these details are covered as such, with their function or functions and with the functional relationship or relationships as described and claimed, provided they occur in partial combinations or in the total combination. | The invention starts from the known method of erecting a pile wall adapted to take compressive forces, from spaced piles and bridging piles cross-connected thereto and intended to close the initially free zones between the spaced piles. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for controlling a warp tension to an appropriate tension value when a loom stops.
2. Description of the Related Art
Japanese Patent Publication No. 36-4029 discloses a technique in which the warp tension is set to be slackened by an electronic control system when a loom stops.
It is effective that the warp tension is slackened when the loom stops for a long period of time. On the contrary, a weaving bar is liable to be generated when the loom stops for a short period of time; hence; the slackening of the warp tension is not an effective means. That is, it is necessary to return the tension value to a normal value when a cloth fell is returned to a regular position in the case of the restarting of the loom after the slackening of the warp. However, inasmuch as a delicate setting of the tension value depends on the kind of texture in consideration of the stretch of the warp during the stoppage of the loom, it is not easy to adjust the warp tension or the position of the cloth fell. If such an adjustment is erroneously made, it causes a new weaving bar.
Thus, even if the warp tension is not slackened when the loom stops for a short period of time, a weaving bar is rarely generated. Accordingly, at this time, it is preferable for the warp tension to not be slackened but kept as it is without generating the cause of the weaving bar due to the slackening of the warp tension.
Particularly, in the recent working or operating mode, the stop time of the loom is largely differentiated depending on the mode of working. That is, when the loom stops during normal working hours, an operator removes the cause of the stoppage in a relatively short time and sets the loom to be restarted so that the stop time is relatively short. On the other hand, when the loom stops once during unmanned operating hours, such as night time or holidays, the loom stops for a continuous long period of time until the succeeding normal working hours occur. Under such circumstances, it is necessary to control the warp tension so as to be an appropriate value depending on the length of the stop page of time of the loom.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to realize a warp tension control apparatus capable of setting the warp tension value to an appropriate value depending on the length of time that the loom is stopped and for setting the warp tension to an appropriate slack.
To achieve the above object, the present invention is provided with a long period stop mode controller whose output is selectively supplied by a selector switch to a warp tension slack means. The warp tension slack means may comprise a take-up control system or a tension roller position control system and the like in addition to a let-off control system and the like.
The long period stop mode controller comprises a first control unit for slackening the warp tension when the loom stops for a long period of time and a second control unit for previously setting the warp tension to a normal tension before the loom starts, if need be. These first and second control units can be driven by a signal to be issued at a given time in addition to a loom stop signal and the like.
When the set switch is selected to a normal stop mode during normal working hours, a long period stop mode control does not operate the warp tension slack means when the loom stops.
Meanwhile, the operator switches the selector switch to the long stop mode before the start of the unmanned operating hours, such as night time or holidays. Accordingly, when the loom stops during the unmanned operating hours, the first control unit in the long period stop mode controller drives the warp tension slack means so that, the warp tension is adjusted to approach a predetermined slack tension. The second control unit in the long period stop controller drives the warp tension control means before the start of the normal working hours so that the warp tension is set to a predetermined normal tension, and thereafter prepares for the next start of the loom.
As mentioned above, the warp tension is set to the appropriate value depending on the length of the stop time. It is therefore possible to prevent the generation of weaving bars caused by the stretch of the warp during the loom stop pages.
Inasmuch as the warp tension is set to the appropriate value depending on each mode of stop page of the loom, i.e. the stop page during normal working hours for a short period of time or during unmanned operating hours for a long period of time, the stretch of the warp or the generation of weaving bars is prevented.
As the warp tension is set to the predetermined slack tension and thereafter returned to a normal tension at the stage of preparation for the restart of the loom, the warp tension is automatically returned to a given value before the fixed time at the time of restart of the loom after the loom stops for a long period of time. As a result, the warp tension is set to substantially the same value as the normal tension during the normal weaving operation so that weaving bars can be prevented with assurance.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevation showing a loom employing a warp tension control apparatus according to a first embodiment of the present invention;
FIG. 2 is a block diagram of the warp tension control apparatus according to the first embodiment of the present invention;
FIG. 3 is a block diagram showing a warp tension control apparatus according to a second embodiment of the present invention;
FIG. 4 is a block diagram showing a main portion of a warp tension control apparatus according to a third embodiment of the present invention; and
FIG. 5 is a block diagram showing a warp tension control apparatus according to a fourth embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A warp tension control apparatus according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.
A plurality of warps 2 are fed from a let-off beam 3 and arranged in a sheet and pass through a tension roller 4 along a warp line and through a stop motion 5 and interlaced with wefts 7 at a cloth fell while forming a shed by the shedding motion of a heddle 6, and thereafter beaten by a reed 8, thereby forming a woven fabric 9. The woven fabric 9 is fed through a take-up roller 10 and taken up by a cloth beam 11. The tension of the warp 2 is detected by a tension detector 12 as an electric tension signal at the tension roller 4 which is displaceable during the let-off operation of the warp. The thus detected electric signal is supplied to an operation mode controller 19 in a warp tension control apparatus 13 for serving as a closed loop control. The operation mode controller 19 compares the detected tension signal with a predetermined tension of the warp 2 of the loom during the weaving operation and supplies a resultant comparison signal through an adding point 14 to a driving circuit 15 for cancelling the deviation therebetween, thereby, controlling the rotation of a let-off motor 16 serving as a warp tension slack means. The rotation of the let-off motor 16 is detected by a pulse generator 17 as a train of pulse signals which are converted by an F/V (frequency to voltage) converter 18 into a voltage proportional to the pulse frequency, and fed back to the adding point 14 as negative feedback signals. The operation mode controller 19 controls the tension of the warp 2 to a predetermined tension during the operation of the loom 10. However, when the loom stops once, the control of the tension of the warp 2 is executed by a long period stop mode controller 21 depending on a condition of selection by a selector switch 22.
FIG. 2 shows an arrangement of the long period stop mode controller 21, the adding point 14 and the selector switch 22 interposed between the long period stop mode controller 21 and the adding point 14.
The long period stop mode controller 21 comprises a first setting unit 23 for setting the warp tension to a predetermined target slack tension, a first comparator 24, a first control unit 25, a relay contact 27 for a first relay 26, a second setting unit 28 for setting the warp tension to a predetermined target normal tension, a second comparator 29, a second control unit 30, a relay contact 32 of a second relay 31, and further comprises a clock 33, a time setting unit 34, a comparator 35 and flip-flops 36 and 37 for driving the first and second relays 26 and 31.
The selector switch 22 is connected to the adding point 14 by a movable contact 220 for supplying the output of the long period stop mode controller 21 i.e. the output of the first control unit 25 or the second control unit 30 to the adding point 14 and is connected to the output of the long period stop mode controller 21 by a fixed contact 221, and is connected to e.g. a ground 38 for setting the loom to a normal stop mode by a fixed contact 222.
The operation mode controller 19 compares, as mentioned above, an actually detected tension by the tension detector 12 and the predetermined target tension and drives the driving circuit 15 depending on the deviation between the actually detected tension and the target tension during the loom 1 operation, thereby controlling the rotation of the let-off motor 16. Accordingly, the warp 2 is always let off by the rotation of the let-off beam 3 so that the tension of the warp 2 always equals the target tension. The operator previously switches the selector switch 22 to the fixed contact 222 for the normal stop mode for the normal operation so that the adding output from the selector switch 22 is always set to 0 V . Accordingly, when the loom stops during the weaving operation, the tension control signal alone is supplied to the adding point 14 from the operation mode controller 19. As a result, the tension of the warp 2 is not set to be slackened. Even if the loom 1 is driven forward or backward by an inching operation during the stop page of the loom 1, the operation mode controller 19 carries out the control of rotation of the let-off motor 16 as usual, thereby setting the tension of the warp 2 to the target tension.
The operator operates the selector switch 22 for switching the movable contact 220 to the fixed contact 221 before the mill enters its unmanned operating hours, such as night time or holidays. Accordingly, when the loom 1 stops, the control signal from the long period stop mode controller 21 is supplied to the adding point 14.
When the loom 1 stops owing to a stoppage caused by a weft stop, for example, during unmanned operating hours, a loom stoppage signal of an H level is supplied to the flip-flop 36 so that the flip-flop 36 is set, thereby rendering the relay contact 27 of the first relay 26 ON. At this time, the first comparator 24 makes a comparison between the target slack tension set by the first setting unit 23 and the actually detected tension of the warp 2 detected by the tension detector 12 and issues a signal representing the difference, i.e. deviation of the resultant comparison. The signal, i.e. a deviation signal, is converted by the first control unit 25 as a slack tension control signal and is supplied to the driving circuit 15 by way of the selector switch 22 and the adding point 14. Accordingly, the left-off motor 16 drives the let-off beam 3 toward the let-off direction, i.e. the forward direction, and thereafter sets the tension of the warp 2 to the target slack tension which is sufficiently lower to cope with the long period of stop page of the loom. At this time, the output from the operation mode controller 19 is cancelled.
On the other hand, the comparator 35 compares the time of the clock 33 with the time set by the setting unit 34 and resets the flop-flop 36 at the time when both the time of the clock 33 and the time set by the setting unit 34 coincide, i.e. at a given time which is close to the start of the normal working hours while setting the flip-flop 37. As a result, the second relay 31 is driven for rendering the relay contact 32 ON and the relay contact 27 OFF. Consequently, the second comparator 29 compares the target normal tension set by the second setting unit 28 with the actually detected tension of the warp 2 detected by the tension controller 12, and issues a signal representing the difference, i.e. the deviation of the resultant comparison. The signal, i.e. a deviation signal, is converted by the second control unit 30 as a normal tension control signal and is supplied to the driving circuit 15 depending on the deviation therebetween by way of the selector switch 22 and the adding point 14. The driving circuit 15 drives the let-off motor 16 in the backward direction so that the tension of the warp 2 is increased to the normal tension value for preparation for the restarting of the loom. Accordingly, the time set by the time setting unit 34 is set to be a first normal working hour after the lapse of the unmanned working hours, such as around 8:20 just before 8:30. If the loom 1 is thereafter set in a starting state, the second flip-flop 37 is reset by an operation signal of the loom 1 so that the relay contact 32 is set to be OFF. It is a matter of course that the operator operates the selector switch 22 for switching the movable contact 220 from the fixed contact 221 to the fixed point 222 for preparation of the normal operation. Inasmuch as the target normal tension set by the second setting unit 28 serves for increasing the tension of the warp 2 to the normal tension value for the preparation of the start of the loom 1, it is possible to omit the setting unit 28 and control the target value during the operation of the loom 1 set inside the operation mode controller 19 as the target normal tension instead of the setting unit 28.
The long period stop mode controller 21 sets the tension of the warp 2 to a slack tension value which is lower than the normal tension for the preparation of the long period of stop page of the loom 1 during the unmanned operating hours and returns the tension to the normal tension during the preparation before the normal operation for the next start, if need be.
The selector switch 22 can be a mere on-off switch by omitting the fixed contact 222. At the normal stop page of the loom 1, the selector switch 22 is set to be OFF so that the long period stop mode controller is separated from the adding point 14. When the long period of stop page of the loom is envisaged, the selector switch is set to be ON so that the long period stop mode controller 21 is connected to the adding point 14.
Although the rotation of the let-off motor 16 is controlled for slacking the tension of the warp 2 according to the first embodiment, it is also controlled by a known warp tension slack means such as means for displacing the tension roller 4 or the means for rotating the take-up motor of the take-up roller 10 the take-up direction.
An arrangement of the warp tension control apparatus according to a second embodiment will be described with reference to FIG. 3.
The arrangement of FIG. 3 is provided with the long period stop mode controller 21 independent of the operation mode controller 19 for forming an open loop control system for controlling an exclusive warp tension slack means 40 without receiving the tension detected by the tension detector 12. According to the exclusive warp tension slack means 40, the tension roller 4 and a holder 39 of the tension detector 12 are slidably movable toward the direction for generating the resultant force of the warp 2 by a pneumatic cylinder 41 for displacing the tension roller 4. A pressure regulating valve 42 of the warp tension slack means 40 regulates the air under pressure supplied from the pressure source 43, thereby setting an internal pressure of the pneumatic cylinder 41 to the target slack tension or the target normal tension.
A warp tension control apparatus according to a third embodiment will be described with reference to FIG. 4.
The warp tension control apparatus according to the first and second embodiments discloses that the long period stop mode controller 21 is operated for slackening the warp tension on the basis of a single target slack tension during the loom 1 stoppage.
However, the warp tension control apparatus can measure the time which has elapsed after the stoppage of the loom 1 and further slacken the warp tension after the passage of a given time. That is, a second target slack tension can be set by a third setting unit 51 in addition to the target slack tension set by the first setting unit 23 as illustrated in FIG. 4. A lapsing time measuring unit 58 receives a loom stop signal and measures the passage of time after the loom has stopped. A comparator 57 compares a predetermined lapsing time set by a time setting unit 59 with an actual passage of time measured by a lapsing time measuring unit 58 and issues a signal when the times coincide for resetting the flip-flop 36 while a flip-flop 55 is set. Consequently, the relay contact 27 of the first relay 26 is OFF while a relay contact 54 of a relay 56 is ON. Accordingly, the second target slack tension set by the third setting unit 51 and the actual tension detected by the tension detector 12 are compared with each other by the third comparator 52. As a result, the third comparator 52 issues a second target slack tension control signal which is supplied to the driving circuit 15 by way of the selector switch 22 and the adding point 14. The driving circuit 15 drives the let-off motor 16 in the backward direction so that the tension of the warp 2 is further slackened.
In the weaving mill provided with a centralized control system, a host computer transmits a mode selection command to each loom by way of a transmission line so that each selector switch of each loom can be remotely automatically switched. That is, the movable contact 220 of the selector switch 22 of each loom can be automatically and simultaneously switched to the fixed contact 221 connected to the output of the long stop period stop mode controller 21 at the start of the unmanned operating hours and to the fixed contact 222 at the start of the normal working hours.
The selector switch 22 can be automatically switched to the fixed contact 221 connected to the output of the long period stop mode controller 21 using the signal issued by the timer. That is, the timer measures the passage of time after the stoppage of the loom 1 and the selector switch 22 can be automatically switched to the fixed contact 221 connected to the output of the long period stop mode controller 21 when the measured time exceeds the predetermined time. If the loom 1 has an automatic mending device for mending a defective weft and the like, the selector switch 22 can be automatically switched to the side of the output of the long period stop mode controller 21 when it receives a mending defective signal.
The operation to switch the selector switch 22 to the fixed contact 222 is interlocked with ON operation of a preliminary switch which is pushed before the start of the loom 1 at the start of the normal working hours. It is a matter of course to use a start switch of the loom instead of the preliminary switch. In short, a signal to be issued involved in the start of the loom may be used.
Such an automatic switching of the selector switch 22 makes it possible to prevent the omission of the switching of the selector switch 22 beforehand. The selector switch may comprise a contact switch or a non-contact switch.
A warp tension control apparatus according to a fourth embodiment will be described with reference to FIG. 5 which shows a modification of the arrangement of FIG. 2.
The selector switch 22 is provided in series with the line where the loom stop signal is supplied to the flip-flop 36, i.e. at the input side of the flip-flop 36. The first relay 26 drives interlocking contacts 271 and 272 while the function of the second control unit 30 is carried out by the operation mode controller 19, thereby omitting the second setting unit 28 and the second control unit 30.
If the loom stop signal is generated when the selector switch 22 is switched to the side to which the loom stop signal is supplied, the flip-flop 36 is set, thereby opening the interlocking contact 271 so that the output of the operation mode controller 19 is cancelled while the output of the first control unit 25 is supplied to the driving circuit 15 by way of the interlocking contact 272.
As the flip-flop is set at the fixed time, the interlocking 272 contact is open while the interlocking contact 271 is closed so that the operation mode controller 19 sets the tension of the warp 2 to the normal tension value in preparation for the restart of the loom. | A warp tension control apparatus includes a tension detector for detecting the tension of a warp and an operation mode controller for generating a control signal to drive a motor so as to minimize the deviation between the detected tension and a normal target tension. A long period stop mode controller is included for controlling the tension so that a target slack tension is set to be less than the normal target tension when a loom stop signal has been issued. A selector switch is provided for selectively switching to a contact connected to an output of the long period stop mode controller before entering a long unmanned operating period of the loom, the switch being disposed in a circuit between an input terminal of the long period stop mode controller which receives a loom stop signal and a warp tension slack device. A switch is provided for stopping the output of the operation mode controller when the long period stop mode controller outputs the slack tension control signal such that the warp tension when the loom is stopped is said to be less than that at the time of normal operation only when the selector switch is selectively switched to a contact connected to the output of the long period stop mode controller. | 3 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a §371 National Phase of PCT/EP2006/007134, filed Jul. 20, 2006 and titled Actuator for Units Comprising a Planetary Gear, the entirety of which is hereby incorporated by reference.
The invention is relative to an actuator for units with a planetary gear.
BACKGROUND
It is generally known that, among other things, planetary gears are used for actuators, so that the speed of a drive is reduced with the aid of this planetary gear to a desired slower speed of an actuator.
In a generally known actuator a motor drives an eccentrically arranged gear via an intermediate gear. A rotatably supported planet wheel is connected to the eccentrically arranged gear and rolls in an internal toothing of a sun gear. Due to the different number of teeth of the two gears a relative speed is created that is transmitted via coupling pins built on the planet wheel onto a driving disk. The driving disk is positively connected by a serration to a shaft. In this manner a relatively compact transmission is produced that, however, requires a relatively large space, viewed radially to the axis of rotation of the planetary gear, on account of the arrangement of the motor and of other components. In addition, the type of connection to the unit to be driven is sharply limited on account of the selected construction of such an actuator.
Furthermore, U.S. Pat. No. 3,391,583 also teaches an actuator with planetary gear for valve control in which a drive is provided that drives a driveshaft of the planetary gear with planet carrier and planet wheels via an appropriate intermediate gear. The driveshaft is almost completely enclosed and encapsulated by a housing element and a formed-on output shaft except for the area of an external toothing that forms a part of the intermediate gear. The rotary motion of the drive is transmitted via the intermediate gear with the appropriate translation onto the driveshaft and the planet wheels that for their part drive the output shaft. Drive, driveshaft and output shaft have no common axis of rotation. The previously cited actuator disadvantageously conditions a spatially extended, areal arrangement of drive and planetary gear. This does not make possible a compact construction of the actuator.
SUMMARY
Starting from this state of the art, the invention has the problem of indicating an actuator with a planetary gear that is constructed as compactly as possible, has a construction that is robust as possible and in addition makes possible the greatest versatility in the arrangement of the individual elements of the actuator.
This problem is solved by the invention with the actuator for units with the features disclosed herein.
The actuator for units in accordance with the invention comprises a planetary gear, in particular a planetary differential transmission, whose radially internal area is designed as a hollow shaft and that comprises an output shaft that cooperates with the unit to be operated. The actuator in accordance with the invention is furthermore provided with a drive. The planetary gear comprises a driveshaft that is connected to the drive and can be driven by it, which driveshaft is designed as a first hollow shaft and the output shaft as a second hollow shaft. The actuator in accordance with the invention is characterized in that a planet carrier is provided that is connected to the first hollow shaft in such a manner that or is designed with its radially internal area as a first hollow shaft in such a manner that upon a rotation of the first hollow shaft the rotary motion is also executed by the planet carrier and, that the drive as well as the first and second hollow shafts are arranged in such a manner that that they have a common axis of rotation and at least the smaller of the two inside diameters of the hollow shafts is adapted to the dimensions in the transverse direction of a drive rod of a unit that can be connected to the output shaft, which drive rod is extended substantially in the longitudinal direction.
In this manner the actuator of the invention avoids that a drive rod, frequently a drive spindle of an actuator, takes up the same spatial area close to the common axis of rotation as the planetary gear itself. In particular, this results in the possibility that the actuator can be arranged totally in the area close to the unit to be driven without the stroke of an adjusting body of the unit and therewith the stroke of the corresponding drive rod being a feature that would hinder the arrangement. In this manner on the one hand the actuator itself becomes more compact and on the other hand the constructive design possibilities for the arrangement of the actuator with a unit are increased.
One advantage of the actuator in accordance with the invention can also be seen in the fact that a penetration of a structural component of the unit through the spatial area of the actuator, namely, through the first and the second hollow shaft, is made possible.
In this manner the axes of rotation of the first and of the second hollow shaft as well as of the drive are combined in a common axis of rotation and the advantage furthermore remains that a drive body for a unit can again be established through the inside area of the hollow shafts. In addition, this makes the construction type of the actuator even more compact. The necessary radial space requirement around the common axis of rotation is correspondingly small.
In addition, it is now possible that the first hollow shaft is directly driven by a drive or, in a constructive variant of the actuator of the invention, forms a part of the drive, in particular the armature of an electromotor or the turbine or the impeller of a hydraulic- or pneumatic drive or -motor, or that the first and the second hollow shafts are designed as a common hollow shaft, and that even the common hollow shaft can be constructed in a constructive modification as part of the drive, in particular as the armature or rotor of an electromotor or as a turbine, rotor or impeller is designed as an armature or rotor of the electromotor or as a turbine, rotor or impeller of a of a hydraulic- or pneumatic drive.
In an alternative embodiment of the actuator of the invention an electromotor, hydraulic- or pneumatic drive is used as drive that comprises another hollow shaft as drive shaft that is connected to the first hollow shaft or is designed as the first hollow shaft and which other hollow shaft is designed as an armature or rotor of the electromotor or as a turbine, rotor or impeller of a hydraulic- or pneumatic drive.
The drive shaft designed as the first hollow shaft and the armature or rotor of the electromotor used as drive or of the hydraulic- or pneumatic drive used as drive are designed in one piece in an advantageous embodiment.
In this arrangement too the axes of rotation of the first hollow shaft, of the second hollow shaft and of the other hollow shaft of the drive are combined in a common axis of rotation and the advantage furthermore continues to remain that a drive body for a unit can again be realized through the inside area of the hollow shafts.
As a result of the above, the number of structural components is further reduced and the actuator rendered more compact.
In an advantageous embodiment the actuator comprises a planetary gear, especially a planetary differential transmission, with a planet carrier that comprises at least one planet wheel, with a drive shaft designed as the first hollow shaft, with an output shaft designed as the second hollow shaft and comprises a first internal toothing that is in engagement with a toothing of the at least one planet wheel, and comprises a support gear comprising a second internal toothing that is also in engagement with the toothing of the at least one planet wheel, and with which support gear the occurring forces or torques can be transferred to a housing with an active connection to the latter and the drive forces can be transferred to the at least one planet wheel or the planet carrier with the first hollow shaft, and an imaginary axis of rotation of the at least one planet wheel is always located outside of the inside diameter of the first hollow shaft.
Since the driveshaft as well as the output shaft are designed as hollow shafts, a free area is produced in the area of the axis of rotation of the hollow shafts which area is formed by the inside diameter of the hollow shafts. This free area can advantageously be utilized for the actuator since driven units usually require a certain adjusting lift as a rule that is usually made available by a spindle with a drive nut driven by the actuator. The adjusting lift can be comparatively large relative to the dimensions of the actuator itself.
A significant advantage of the planetary gear in accordance with the above as well as of the corresponding actuator is that the minimal inside diameter of the first and of the second hollow shaft can be given, namely, in particular for the diameter of a previously described driveshaft of a unit. In this manner such a drive spindle can be readily run through the hollow shaft or the hollow shafts of the planetary gear and/or of the actuator. The construction is correspondingly compact and totally new possibilities result for the arrangement of the planetary gear and/or of the actuator relative to the unit to be driven.
In addition, embodiments of a planetary gear and therewith also of an actuator that are especially favorable for oscillations are possible with planet wheels rotating around the first hollow shaft. The rotating masses are relatively small. An optimum of rotating planet wheels is achieved with three of these gears.
Also, the free end, namely, the end of the first hollow shaft, which end faces away from the second hollow shaft, can be provided in an advantageous further development of the planetary gear of the invention with a connecting element, especially a coupling, for connection to a drive.
An additional advantage results if the inside diameters of the first and of the second hollow shaft and/or of the other hollow shaft of the drive are adapted to each other.
It is achieved in this manner that the inside area of the hollow shaft is substantially without steps or offsets with edges and in this manner possible mechanical hindrances for a drive spindle running through the inside areas are avoided in the construction.
A further advantageous embodiment of the actuator is achieved in that the support gear of the planetary gear comprises an external toothing that is engaged with a toothing with a measuring shaft, that the forces and torques transmitted onto the measuring shaft are received by a spring arrangement connected to the measuring shaft, and that the deflection of the spring arrangement is a measurement for the magnitude of the transmitted force or of the transmitted moment.
In this manner the forces and moments are not simply introduced into the housing and dumped there but rather there is the possibility of directly detecting or indicating the magnitude of the force to be transmitted or of the moment to be transmitted, e.g., via an appropriate display device. Furthermore, this creates an elegant possibility of manually rotating the support gear, e.g., via an appropriate hand wheel. The rotation of the second hollow shaft and takes place directly without the complete reduction of the planetary gear being active.
Further advantageous embodiments of the subject matter of the invention can be gathered from the dependent claims concerning the actuator in accordance with the invention.
The invention, advantageously designed improvements of the invention as well as special advantages of the invention are explained and described in detail using exemplary embodiments represented in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a first actuator
FIG. 1B shows the first actuator including a drive spindle of a unit and
FIG. 2 shows a second actuator for units with a planetary gear.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1A and 1B show a first actuator 10 comprising a first servomotor 12 as well as a first planetary gear 14 designed as a planetary differential transmission. These figures only show the essential mechanical parts necessary for explaining the planet transmission in accordance with the invention and the actuator in accordance with the invention. Thus, e.g., no housing is shown. However, it can be supplemented as needed by the knowledge of an expert in the art so that the customary but not shown structural parts for completing an actuator can be readily completed by an expert in the art.
The first servomotor 12 comprises a first hollow shaft 16 as drive shaft on whose one end a first shaft bearing 18 with a first shaft seal 20 is arranged, which arrangement comprises a recess 22 in the area of the first hollow shaft 16 which recess does not cover the inside area 24 of the first hollow shaft 16 at any position. The inside area 24 has a uniform diameter in its complete longitudinal extension.
The first hollow shaft 16 extends at its other, free end by a certain length over the spatial end of the longitudinal extension of a stator 26 of the first servomotor 12 by a length that ensures that the essential mechanical elements of the first planet transmission 14 can be arranged on this shaft end. Thus, in this arrangement first hollow shaft 16 is designed as the rotor shaft or armature shaft of first servomotor 12 as well as the drive shaft for first planet transmission 14 .
The free end of the first hollow shaft comprises the end area of the first hollow shaft facing away from the planet carrier as well as from the second hollow shaft.
A shoulder is formed on the outer jacket surface of the just described other shaft end on which shoulder a planet carrier 28 is arranged. The connection between planet carrier 28 and first hollow shaft 16 can be positively established in an especially simple manner, e.g., by a spring connection or non-positively, e.g., by a shrinking connection or also by other connection techniques familiar to an expert in the art. In addition, it is ensured that the drive forces pass-through first hollow shaft 16 into in a planet carrier 28 so that upon a rotation of first hollow shaft 16 the rotary motion is also executed by planet carrier 28 .
In the selected example planet carrier 28 carries three planet wheels and in this sectional view of actuator 10 only a first planet wheel 30 is shown. This planet wheel is supported in such a manner that it can rotate about support bolt 32 held in corresponding recesses of planet carrier 28 . According to the invention one planet wheel is sufficient for this. For reasons of oscillation technology a higher number of planet wheels are advantageous. A preferred number is achieved with three planet wheels.
The teeth of an external toothing of the planet wheels, that is, even of first planet wheel 30 , engage into the particular internal toothing of a first 34 as well as of a second gear ring 36 and roll over them in accordance with the toothing ratios. The first gear ring 34 is connected by a first connection pin 38 to a second hollow shaft 40 whereas the second gear ring is connected via a second connection pin 42 to a support gear 44 . Connection pins 38 , 42 establish a secure connection between the particular gear rings 34 , 36 and their carriers, that is, second hollow shaft 40 and support gear 44 .
In addition, support gear 44 also comprises an external toothing 46 that is engaged with a measuring shaft 48 . To this end measuring shaft 48 has a spiral area in its outer jacket surface. Measuring shaft 48 is then supported in a housing that is not shown in this figure so that any occurring forces and moments are reliably conducted away through the measuring shaft into this housing.
Such forces can arise as follows. The first hollow shaft 16 is rotated by first servomotor 12 and thus planet carrier 28 too. In an embodiment of the planetary gear that is favorable from an oscillation technology standpoint three planet wheels are provided, as present here, that are obligatorily moved by the rotation of planet carrier 28 . Forces and moments are transferred onto support gear 44 by the rolling of the planet wheels in the internal toothing of second gear ring 36 , which support gear finally transmits them into measuring shaft 48 . In the view of the measuring shaft as a section through the latter selected in FIG. 1 the just described forces act in its longitudinal direction, so that an appropriate arrangement of springs in its longitudinal direction would be an advantageous possibility for receiving the forces. A possibility is then advantageously achieved for measuring the forces by measuring the deflection of the springs. In addition, the fixing of measuring shaft 48 in the housing brings it about that support gear 44 moves out of its angular position under the influence of the forces and moments only to a minimal extent. The power introduced by the planet wheels into the internal toothing of gear rings 38 , 36 will accordingly only put the first gear ring 34 into a rotary movement. This gear ring is namely rotatably supported together with second hollow shaft 40 via a second shaft support 50 . In this manner the transmission of forces and moments from the drive shaft, namely, the first hollow shaft 16 , onto the output shaft, namely, the second hollow shaft 40 , is ensured.
The difference in the number of teeth of the internal toothing between first gear ring 34 and second gear ring 36 must only be an even multiple of the number of planet wheels present for mechanical reasons. In this manner the reduction ratio of the first planetary gear 14 can be especially readily adjusted in the construction via the number of planet wheels and the design of the internal toothings of the rings 34 , 36 .
Comparable to the situation on first shaft bearing 18 , a second shaft seal 52 is also arranged on second shaft bearing 50 which ensures on the one hand that any dirt particles that may be present in the surroundings of first actuator 10 can not pass in the direction of the planetary gear. Even second shaft bearing 50 is supported in the final analysis in its radially external area on a housing of the planetary gear, which is not, however, shown in this figure. A suitable support of the shaft arrangement of first hollow shaft 16 and second hollow shaft 40 is ensured in that a third shaft support 54 with a third shaft seal 56 is arranged at a suitable location between servomotor 12 and first planetary gear 14 on the first hollow shaft 16 .
Second hollow shaft 40 has different inside diameters along its longitudinal axis corresponding to its function, of which, however, an extremely small inside diameter 58 corresponds to the diameter of inside area 24 . These diameters are adapted to each other. It is ensured in this manner that, e.g. a lift spindle of a unit spindle drive to be driven can be readily run through the two hollow shafts 16 , 40 without there being any mechanical trouble spot. The connection of the first actuating transmission to a unit to be driven or to its lift drive or lift linkage is shown only schematically here. In this embodiment a groove 60 is shown on the side of second hollow shaft 40 facing away from the first servomotor 12 which groove constitutes a positive transfer of force of the forces conducted through second hollow shaft 40 , e.g., onto a drive nut 62 that fits into this groove 60 . In this manner the drive nut is put into a rotary movement but hindered in its spatial progress in the longitudinal direction of the axis of rotation of second hollow shaft 40 . Thus, a drive spindle 64 guided in the drive nut 62 is forced into a movement running in the longitudinal direction of the axis of rotation of second hollow shaft 40 . Thus, in the end the rotary movement of second hollow shaft 40 is converted into a longitudinal movement of a lift spindle 64 of a unit.
It is of course also conceivable that such a drive only has to make a slight rotary movement such as is required, e.g., for opening and closing ball valves, namely, a quarter circular turn. The rotary motion of first hollow shaft 16 is ensured solely via first servomotor 12 . Thus, e.g., an appropriate regulation of the speed of first servomotor 12 can be used in the end to change or regulate the opening speed or the closing speed of the activated unit. In this manner even any desired closing- or opening profiles with changing speeds can be performed. However, it is also a customary case that first servomotor 12 is operated at a constant speed.
The translation of the drive power of first hollow shaft 16 as regards power and torques is ensured by a suitable selection of the translation ratios in the planetary gear, namely, the suitable selection of the number of teeth of the planet wheels as well as of gear rings 34 , 36 . In a simple case the number of teeth of internal toothing of the first gear ring 34 as well as of the second gear ring 36 can differ by only a few teeth, e.g., three teeth in a planetary gear with three planet wheels, especially with a total tooth number of gear rings of 72 and 75 teeth. However, even larger differences of tooth numbers are possible.
Note that second hollow shaft 40 only rotates when the tooth number between gear ring 34 and 36 is different.
The translation ratio of the transmission results from the ratio of the tooth number of the planet wheels and of first gear ring 34 and of second gear ring 36 . First gear ring 34 and second gear ring 36 must have a different number of teeth, as was already explained above.
The described embodiment of the actuator in accordance with the invention has the advantage that an especially small construction volume is achieved, in particular when viewed in the radial direction to the axis of rotation of first hollow shaft 16 and second hollow shaft 40 . In addition, the planetary gear used in accordance with the invention ensures an especially high efficiency and is distinguished by the planet wheels rotating about first hollow shaft 16 with an especially good quietness. An optimum of quietness is achieved if three planet wheels are used
FIG. 2 shows a second actuator 70 comprising a second servomotor 72 and a second planetary gear 74 . Many essential parts of second planetary gear 74 are designed like the corresponding parts of first planetary gear 14 so that the reference numerals from FIG. 1 are used for these parts. Therefore, in the following even the differences between the first actuator 10 and the second actuator 70 will be discussed in particular.
In distinction to the first actuator 10 in the second actuator 70 a third hollow shaft instead of first hollow shaft 16 is the shaft that carries planet carrier 28 and is connected to the latter. Third hollow shaft 76 has a comparable inside area 24 that for its part has a diameter corresponding to the minimal inside diameter 58 . The third hollow shaft 76 has a externally toothed third gear ring 78 on its end facing away from second hollow shaft 40 . This ring engages into the teeth of a fourth gear ring 80 connected to a shaft end of a drive rotor 82 of the second servomotor 72 . The dimensions of the third gear ring 78 as well as of the fourth gear ring 80 are selected in such a manner that on the one hand the translation ratios corresponding to the tooth number of gear rings 78 , 80 are suitable for the technical problem of the second actuator 70 to be solved and in addition the second servomotor 72 is located outside of an imaginary area resulting by a prolongation of the longitudinal extent of the inside area of the third hollow shaft 76 . This ensures in any case that a drive spindle run through second hollow shaft 40 and third hollow shaft 76 can not collide with any other part of second actuator 70 .
This measure brings it about that second servomotor 72 can be an especially economical standard motor. In addition, an increased flexibility in the designing of the translation ratios between second servomotor 72 and second hollow shaft 40 results from the different possibilities for the selection of the third gear ring 78 and of the fourth gear ring 80 .
LIST OF REFERENCE NUMERALS
10 first actuator
12 first servomotor
14 first planetary gear
16 first hollow shaft
18 first shaft support
20 first shaft seal
22 recess
24 inside area
26 stator
28 planet carrier
30 first planet wheel
32 support bolt
34 first gear ring
36 second gear ring
38 first connection pin
40 second hollow shaft
42 second connection pin
44 support gear
46 external toothing
48 measuring shaft
50 second shaft bearing
52 second shaft seal
54 third shaft support
56 third shaft seal
58 minimal inside diameter
60 groove
62 drive nut
64 drive rod or spindle
70 second actuator
72 second servomotor
74 second planetary gear
76 third hollow shaft
78 third gear ring
80 fourth gear ring
82 drive rotor | The invention relates to an actuator ( 10 ) for units comprising a planetary gear ( 14 ), especially a planetary differential gear, whose radially inward region is embodied as a hollow shaft and which is equipped with a drive unit and a driven shaft that cooperates with the unit to be operated. A drive shaft of the planetary gear ( 14 ) is connected to the drive unit and can be driven by the same. Said drive shaft is configured as a first hollow shaft ( 16 ) while the driven shaft is embodied as a second hollow shaft ( 40 ). A planet carrier ( 28 ) is provided that is connected to the first hollow shaft ( 16 ) or is embodied with the radially inward region thereof as a first hollow shaft ( 16 ) in such a way that a rotary movement is also performed by the planet carrier ( 28 ) when the first hollow shaft ( 16 ) rotates while the drive unit as well as the first ( 16 ) and the second hollow shaft ( 40 ) encompass a common axis of rotation. Furthermore, at least the smaller of the two internal diameters of the hollow shafts is adapted to the transversal dimensions of a substantially longitudinally extending drive rod of a unit which can be connected to the driven shaft. | 5 |
FIELD OF THE INVENTION
[0001] The present invention relates to a stepladder safety device. The invention particularly is directed to a safety device for a stepladder which prevents or deters the user of the stepladder from standing on the top step and top platform of the stepladder. The invention also is directed to stepladders having such safety device as an integral part of the stepladder.
BACKGROUND OF THE INVENTION
[0002] Stepladders are widely used in situations where extension ladders, fixed ladders or other single sided ladders will not work or are impractical. Specifically, stepladders are a freestanding A-frame type construction with standard sizes running from about 2 feet to about 16 feet in height and taller. Stepladders tend to be more stable in use than extension ladders due to the base formed by the A-frame construction. Stepladders, however, have a safety drawback in that the top platform and top step of a stepladder are unstable positions and thus not suited for actually standing on, even though the construction and design of the top platform and top step are such that standing on them is possible. OSHA regulations have made it illegal to use the top platform and top step of stepladders in commercial construction situations. All stepladders sold in the United States for commercial or residential use must have a warning on the top step and top platform not to stand upon them. The top platform and top step of a stepladder are cross members positioned for the structural integrity of the stepladder but are normally shaped like steps and indistinguishable from the rest of the steps of a stepladder. These design choices, made by stepladder manufacturers, add to the problems associated with the safety of stepladders. In situations where a little extra height is needed by the user already on a stepladder, it is easy to ignore or just forget the rules, regulations and printed warnings for the stepladder and use what looks like a step, i.e. the top step or top platform, to gain extra height rather than obtain a larger stepladder. This scenario is especially true in commercial situations where workers are judged on the quantity of work they produce per unit of time and therefore safety is often disregarded in favor of ease or speed. Misuse of stepladders has become such a problem with construction workers that an OSHA representative frequently visits construction sites looking for violations of the safety rules relating to stepladders. Citations against construction companies are frequent, as are accidents caused by misuse of the top step and top platform of stepladders.
[0003] Guards for preventing or deterring people from climbing ladders are well known. However, such ladder guards have been limited to extension ladders and single sided non-extending ladders, e.g. on the sides of pools, buildings and the like. Essentially, the guards have been flat members covering a majority of the rungs on the ladder in a manner that the ladder cannot be used at all for its intended purpose. Such guards are designed to prevent unauthorized use of the ladder and need to be removed before any normal use of the ladder can be made. Normally, these types of safety devices are attached to the middle portion of the ladder and do not prevent use of the uppermost rung or step of the ladder. They simply prevent one from getting to them. None of the known guards are specifically directed for use on a stepladder. Further, none of the known guards are designed to be in use at the same time the stepladder is being used.
[0004] It would therefore be useful and the present invention has as its primary object to provide a safety device for a stepladder or provide a stepladder having a safety device as an integral part of the stepladder, to prevent use of the top step and top platform of the stepladder while still allowing normal use of the stepladder. Other objects will become apparent as the description proceeds.
SUMMARY OF THE INVENTION
[0005] In fulfillment of the objects of the invention, a detachable stepladder safety device is provided according to one form of the invention. Also provided, according to another embodiment of the invention, is a stepladder having a safety device made as an integral part of the stepladder. In both embodiments, the safety device prevents use of the top step and top platform of the stepladder.
[0006] Specifically, the present invention, according to the first form referred to above, provides a safety device adapted to fit over the top platform and upper portions of an erect stepladder and comprises: a cap portion formed by an outwardly extending front wall and back wall, and a substantially closed top adapted, when the safety device is installed on the erect stepladder, to position the cap portion immediately above the top platform and position the front and back walls to surround the top platform and selected upper portions of the stepladder. The safety device is shaped in a manner designed to deter and prevent normal use of the top platform and of the top step of the stepladder.
[0007] The cap portion can have a variety of shapes to achieve the goal of the invention. It is the essence of the invention that the shape of the cap portion is such that it prevents or deters normal level standing i.e. normal use of the top platform. The front and back wall essentially come together to form a substantially closed top. So, for example, the cap portion can be shaped to form a peak, a ridge or any shape which makes normal use of the top platform difficult or impossible.
[0008] The front wall of the safety device extends downward from the cap portion such that it blocks or covers the top step of the stepladder in a manner that deters or prevents normal use of the top step of the stepladder. Various shapes may be used. For example, the front wall may be shaped as a flat sheet extending downward from the cap portion wide enough and long enough to extend past the top step.
[0009] While the safety device of the invention is primarily designed to be added to an existing conventional stepladder, it is also contemplated that the stepladder can be constructed with the safety device being an integral part of the stepladder.
[0010] Attaching the safety device of the invention to a stepladder can be achieved by any suitable means. So, for example, it can be attached using screws, clips, hook and loop fasteners, rivets, grommets or the like. In one form of the invention, the safety device cap portion has an open bottom so that the safety device press fits over the top platform of the stepladder. In another form, the safety device is screwed to the stepladder. The safety device of the invention, in still another form, provides a stepladder with such safety device as an integral part thereof.
[0011] The stepladder safety device, of the present invention lends itself to being formed of metal, plastic, wood, plastic impregnated fabric cloth or the like and may be of welded, molded, or other construction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a fragmentary exploded perspective view of a first embodiment of the invention ready to be mounted on a stepladder, the stepladder being shown in dashed lines for purpose of illustration.
[0013] [0013]FIG. 2 is a fragmentary perspective view of the first embodiment of the invention of FIG. 1 mounted on a conventional stepladder.
[0014] [0014]FIG. 3 is a perspective view of the first embodiment of the invention of FIG. 1 illustrating its open bottom.
[0015] [0015]FIG. 4 is a perspective view of a second embodiment of the invention.
[0016] [0016]FIG. 5 is a perspective view of a third embodiment of the invention.
[0017] [0017]FIG. 6 is a fragmentary perspective view of a fourth embodiment of the invention in which the stepladder safety device of the invention is formed to serve as an integral part of a stepladder.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Referring now to the drawings in greater detail. FIG. 1 is a fragmentary, exploded perspective view of the first embodiment of the invention stepladder safety device 7 and a conventional stepladder 9 onto which it is placed. Cap portion 11 has a tapered ridge design that comes to a rounded edge 8 formed by a pair of opposing sides 10 , a downwardly and outwardly inclined front wall 12 and a downwardly and outwardly inclined back wall 24 (FIG. 3). When safety device 7 is placed on stepladder 9 , safety device 7 covers the stepladder top platform 16 and top step 14 , deterring or preventing their normal use. FIG. 2 is a perspective view of safety device 7 showing cap portion 11 appropriately sized and affixed, by means of a press fit, over top platform 16 of stepladder 9 . Front wall 12 of the safety device 7 , once in place, covers top step 14 preventing normal use of both top step 14 and platform 16 of stepladder 9 . Cap portion 11 has a pair of opposing sides 10 which fit correspondingly over the sides 20 of stepladder 9 and top platform 16 .
[0019] [0019]FIG. 3 is a perspective view, looking upward into cap portion 11 , of safety device 7 . Front wall 12 , side walls 10 , and back wall 24 surround opening 22 under cap portion 11 . In this first embodiment, opening 22 is sized to fit over top platform 16 of stepladder 9 for the purpose of installing it and retaining it on stepladder 9 by means of a press fit. Open bottom 22 is thus a useful feature since it can be sized to fit relatively snugly over top platform 16 and yet be easily removed. Nevertheless, it is recognized that cap 11 could be formed with a closed bottom (not shown) joined to the front, side and back walls and adapted to rest on platform 16 .
[0020] [0020]FIG. 4 is a perspective view of a second embodiment of the invention, numbered stepladder safety device 32 . In this embodiment, sloping walls 37 a , 37 b , 37 c , 37 d of cap portion 34 forms a point 35 rather than a tapered ridge as in the first embodiment. Stepladder safety device 32 also includes a front wall 36 , a pair of opposing sidewalls 38 , and a rear wall 40 . Stepladder safety device 32 fits on the top platform of a stepladder in the same manner as stepladder safety device 7 of the first embodiment.
[0021] [0021]FIG. 5 is a fragmentary perspective view of a stepladder safety device 42 of the invention according to a third embodiment. In this third embodiment, stepladder safety device 42 has a curved cap portion 44 but no side walls as in the other embodiments. Stepladder safety device 42 has a front wall 46 which covers the top step of a conventional stepladder. In this third embodiment, stepladder safety device 42 can be mounted on and attached to a conventional stepladder using mounting holes 50 by use of screws, nails, or the like (not shown) that fit through mounting holes 50 and into the conventional stepladder. This is an especially effective attachment method for conventional stepladders made of wood.
[0022] [0022]FIG. 6 is a fragmentary perspective view of a stepladder safety device of the present invention according to a fourth embodiment. In this fourth embodiment, stepladder safety device 62 is formed and welded or molded, dependent on the material being used, as an integral part of stepladder 64 and covers an existing top platform. Stepladder safety device 62 thus replaces or makes unavailable for use the top platform and top step.
[0023] It is clear that there will be variations in the shape of the cap portion, and walls including the front wall, means of attachment, and the like within the scope of the invention. Those skilled in the art, to which this invention pertains, will clearly understand those variations and the claimed scope of the invention. | The present invention relates to a stepladder safety device which fits on the upper portion of a conventional stepladder and is shaped to prevent or deter normal use of the top platform and top step of the stepladder. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for controlling the speed change of a vehicle automatic transmission, and in particular to improved technology related to speed change control at the time of deceleration.
2. Description of the Related Art
In general with a vehicle automatic transmission, speed change is carried out automatically based on a speed change pattern previously set in accordance with vehicle running conditions.
More specifically, a speed change pattern for setting speed change steps in accordance with vehicle speed and engine load (for example throttle valve opening), is stored in a storage device in the control section, and speed change is controlled according to this speed change pattern. Normally under small speed change pattern is set such that if the vehicle speed is the same, there is a tendency to shift up, the smaller engine load.
However, with such a conventional automatic speed change control, since for example, at the time of descent there is an up shift contrary to the deceleration requirements of the driver who fully closes the throttle, then a different or disconcerting sensation inconsistent with the deceleration requirements of the driver is experienced. Moreover, the deceleration effect from engine braking is not realized. The driveability of the vehicle is thus impaired, and excessive loading is applied to the brakes.
In order to solve this problem at the time of descent, there has been proposed, for example as disclosed in Japanese Unexamined Patent Publication No. 4-4351, a speed change device wherein the speed change is controlled to an optimum speed change step so as to obtain a desired acceleration at the time of descent, by computing the engine generated torque based on the throttle valve opening and the engine rotational speed, then computing the vehicle running resistance based on the computed generated torque, the vehicle acceleration, and the vehicle weight, and comparing the vehicle running resistance with set values set beforehand in accordance with the speed change steps.
With this device however, the speed change is controlled to obtain a desired acceleration at the time of descent based on vehicle conditions only, irrespective of the deceleration intention of the driver. This results in a different or disconcerting sensation being experienced by the driver. Moreover, a map (see FIG. 20) is required wherein the speed change timing is set in accordance with the speed change steps, thus necessitating a large memory for storing the map.
SUMMARY OF THE INVENTION
In view of the abovementioned problems with the conventional technology, it is an object of the present invention to provide a method and apparatus for controlling the speed change of a vehicle automatic transmission, which can optimize speed change control at the time of deceleration (for example at the time of descent), to suppress the different sensation experienced by the driver and improve vehicle drivability, while at the same time reducing computer memory capacity and hence cost. Moreover, it is an object of the present invention to significantly increase the accuracy and simplify the construction of such a control method and apparatus.
To achieve the above object, a method and apparatus according to a first aspect of the present invention for controlling the speed change of a vehicle automatic transmission wherein the vehicle automatic transmission is connected to an engine output shaft, comprises;
a vehicle speed detection step or device for detecting vehicle speed,
a vehicle running resistance detection step or device for detecting vehicle running resistance,
an engine load detection step or device for detecting engine load,
a deceleration intention detection step or device for detecting a deceleration intention of a driver based on the engine load,
a first vehicle acceleration estimation step or device for estimating vehicle acceleration in the case of a speed change to a speed change step on a lower speed side of a current speed change step, based on the vehicle speed and vehicle running resistance,
a target acceleration setting step or device for setting a target acceleration,
a first acceleration comparison step or device for comparing the vehicle acceleration estimated by the first vehicle acceleration estimation step or device, with the target acceleration set by the target acceleration setting step or device, and
a first speed change control step or device for controlling speed change by selecting (speed change control), at the time of detecting a deceleration intention of the driver by the deceleration intention detection step or device, a speed change step to give a vehicle acceleration after speed change equal to or above the target acceleration, based on the comparison results of the first acceleration comparison step or device.
With the present invention incorporating such a construction, the vehicle acceleration for the case of down-shift from the current speed change step is estimated by the first vehicle acceleration estimation step or device, and the estimated vehicle acceleration compared with a target acceleration to select a speed change step to give a vehicle acceleration after speed change equal to or above the target value (that is to say so that there is no excessive deceleration). On the other hand, the deceleration intention of the driver is determined, and in the case of no deceleration intention, the speed change control by the first speed change control step or device for the down slope is prohibited in order to respect the will of the driver and avoid giving a different sensation, and speed change control is carried out according to the normal speed change pattern. Speed change to the speed change step selected by the first speed change control step or device is thus limited to the case where there is driver deceleration intention.
As a result, down slope speed change control which respects the deceleration intention of the driver can be carried out, and speed change can be to a speed change step for an acceleration which does not give excessive deceleration (for example a value close to and above 0). It is thus possible to obtain good deceleration characteristics corresponding to the gradient without the driver experiencing a different sensation of an excessive engine braking effect. Hence vehicle driveability on a down slope can be optimized.
The selection of a speed change step to give a vehicle acceleration after speed change equal to or above a target value so that the driver does not experience a different sensation of an excessive engine braking effect, is a very important point. More specifically, if the driver experiences even a slight excess deceleration, since the driver has no effective means to avoid this different sensation, it cannot be easily overcome. However, if a speed change step is selected to give a vehicle acceleration after speed change equal to or above the target value, then for example even if the driver experiences this as a different sensation, since this will be one of excess acceleration, it can very easily overcome by applying the brake.
Moreover, by comparing the vehicle acceleration estimated by computation, with the target acceleration, to thereby select the speed change step, then a map requiring a large memory, as with the conventional arrangement (see FIG. 20) wherein the speed change timing is set in accordance with the speed change steps, is not required. Hence costs can be reduced.
The first vehicle acceleration estimation step or device may be constructed such that the vehicle acceleration is estimated when the throttle valve is fully closed.
More specifically, at the time of descent, the driver desires to travel at with the throttle valve fully closed a constant predetermined acceleration (for example approximately 0). Therefore to correspond to this situation, estimation of the vehicle acceleration by the first vehicle acceleration estimation step or device is carried out with the throttle valve fully closed, to thus enable down slope travelling under conditions wherein the driver does not experience a different sensation. In this way, the requirements of the driver can be met.
The first speed change control step or device may be constructed to control speed change by selecting a speed change step on the lowest speed side of the speed change steps which give a vehicle acceleration after speed change equal to or above the target acceleration.
More specifically, the first speed change control step or device controls speed change by selecting the speed change step on the lowest speed side of the speed change steps which gives the vehicle acceleration estimated by the first vehicle acceleration estimation step or device equal to or above the target acceleration. In this way, a maximum engine braking effect can be applied within a range which is not felt as excessive by the driver.
The construction may be such that at the time of brake operation by the driver, speed change control by the first speed change control step or device is not carried out.
More specifically, since vehicle running resistance detection accuracy is reduced when the driver operates the brake, then good final speed change control is lost. Therefore in the case of brake operation, speed change control by the first speed change control step or device is prohibited to avoid this undesirable situation.
Furthermore, the construction may be such that at the time of brake operation, the vehicle running resistance detected by the vehicle running resistance detection step or device, or the target acceleration set by the target acceleration setting step or device, is corrected.
That is to say, when the driver operates the brake, the vehicle running resistance detected by the vehicle running resistance detection step or device, or the target acceleration set by the target acceleration setting step or device is corrected, so that the speed change control accuracy even with brake operation can be improved. In this way, down slope speed change control can be carried out with a more highly accurate first speed change control step or device.
The invention as described above is arranged with speed change to the down-shift side to enable travelling at a desired acceleration at the time of descent. However an arrangement is also possible as with the invention described below, with speed change to the up-shift side to enable travelling at a desired acceleration at the time of descent. That is to say, to deal with the situation when the down slope gradient is gentle, or when the current speed change step is on the low side, and the driver will experience a different sensation of excess deceleration if up-shift is not carried out.
In this case, a method and apparatus according to a second aspect of the present invention for controlling the speed change of a vehicle automatic transmission which is connected to an engine output shaft comprises;
a vehicle speed detection step or device for detecting vehicle speed,
an engine load detection step or device for detecting engine load,
a deceleration intention detection step or device for detecting a deceleration intention of a driver based on the engine load,
a vehicle acceleration detection step or device for detecting vehicle acceleration,
a target acceleration setting step or device for setting a target acceleration,
a second acceleration comparison step or device for comparing the vehicle acceleration detected by the vehicle acceleration detection step or device, with the target acceleration set by the target acceleration setting step or device, and
a second speed change control step or device for controlling speed change from a current speed change step to a speed change step on the higher side, when a deceleration intention of the driver is detected by the deceleration intention detection step or device, and the comparison results of the second acceleration comparison step or device, give the vehicle acceleration detected by the vehicle acceleration detection step or device as less than the target acceleration.
With such a construction, the current vehicle acceleration and the target acceleration are compared, and when in the current speed change step the deceleration is excessive so that the driver experiences a different sensation, a down slope speed change control is carried out by means of the second speed change control step or device, to shift up to a speed change step on a higher side than the current speed change control step. The deceleration intention of the driver however is determined, and in the case of no deceleration intention, the speed change control by the second speed change step or device for the down slope is prohibited in order to respect the will of the driver and avoid giving a different sensation, and speed change control is carried out according to the normal speed change pattern. Up-shift control by the second speed change control step or device is thus limited to the case where there is driver deceleration intention.
As a result, down slope speed change control which respects the deceleration intention of the driver is carried out, with up-shift to a speed change step for an acceleration which does not give excessive deceleration. It is thus possible to obtain good deceleration characteristics corresponding to the gradient without subjecting the driver to a different sensation such as an excessive engine braking effect. Hence vehicle drivability on a down slope can be optimised. As with the beforementioned invention, the selection of a speed change step to give a vehicle acceleration after speed change equal to or above a target value so that the driver does not experience a different sensation such as an excessive engine braking effect, is a very important point.
Moreover, since up-shift is made by comparing the detected vehicle acceleration with the target acceleration, then construction can be simplified, and a map requiring a large memory, as with the conventional arrangement (see FIG. 20) wherein the speed change timing is set in accordance with the speed change steps, is not required. Hence costs can be reduced.
The construction may be such that at the time of brake operation, speed change control by the second speed change control step or device is not carried out.
More specifically, since vehicle acceleration detection accuracy is reduced when the driver presses the brake, then good final speed change control is lost. Therefore in the case of brake operation, speed change control by the second speed change control step or device is prohibited to avoid this undesirable situation.
Furthermore, the construction may be such that at the time of brake operation, the vehicle acceleration detected by the vehicle acceleration detection step or device, or the target acceleration set by the target acceleration setting step or device, is corrected.
That is to say, when the driver operates the brake, the vehicle acceleration detected by the vehicle acceleration detection step or device, or the target acceleration set by the target acceleration setting step or device is corrected, so that the control accuracy even with brake operation can be improved. In this way, down slope speed change control can be carried out with a more highly accurate second speed change control step or device.
In the case where speed change is to the up-shift side to enable travelling at a desired acceleration at the time of descent, an even greater accuracy is possible with the following construction.
That is to say, a method and apparatus according to a third aspect of the present invention for controlling the speed change of a vehicle automatic transmission which is connected to an engine output shaft comprises;
a vehicle speed detection step or device for detecting vehicle speed,
a vehicle running resistance detection step or device for detecting vehicle running resistance,
an engine load detection step or device for detecting engine load,
a deceleration intention detection step or device for detecting a deceleration intention of a driver based on the engine load,
a second vehicle acceleration estimation step or device for estimating vehicle acceleration in the case of travelling in a speed change step on the high speed side including the current speed change step, based on the vehicle speed and vehicle running resistance,
a target acceleration setting step or device for setting a target acceleration,
a third acceleration comparison step or device for comparing the vehicle acceleration estimated by the second vehicle acceleration estimation step or device, with the target acceleration, and
a third speed change control step or device for controlling speed change by selecting, at the time of detecting a deceleration intention of the driver by the deceleration intention detection step or device, a speed change step to give a vehicle acceleration estimated by the second vehicle acceleration estimation step or device equal to or above the target acceleration, based on the comparison results of the third acceleration comparison step or device.
With such a construction, the vehicle acceleration for the case of an up-shift (also including the case wherein the current speed change step is maintained), estimated by the second acceleration estimation step or device is compared with the target acceleration to select a speed change step to give a vehicle acceleration after speed change equal to or above the target value (that is to say so that there is no excessive deceleration). On the other hand, the deceleration intention of the driver is determined, and in the case of no deceleration intention, the speed change control by the third speed change step or device for the down slope is prohibited in order to respect the will of the driver and avoid giving a different sensation, and speed change control is carried out according to the normal speed change pattern. Speed change to the speed change step selected by the third speed change control step or device is thus limited to the case where there is driver deceleration intention.
As a result, down slope speed change control which respects the deceleration intention of the driver can be carried out, and speed change can be to a speed change step for an acceleration which does not give excessive deceleration (for example a value close to and above 0). It is thus possible to obtain good deceleration characteristics corresponding to the gradient without subjecting the driver to a different sensation such as an excessive engine braking effect. Hence vehicle drivability on a down slope can be optimised. The selection of a speed change step to give a vehicle acceleration after speed change equal to or above a target value so that the driver does not experience a different sensation such as an excessive engine braking effect, is a very important point.
Moreover, by comparing the vehicle acceleration estimated by computation, with the target acceleration, to thereby select the speed change step, then a map requiring a large memory, as with the conventional arrangement (see FIG. 20) wherein the speed change timing is set in accordance with the speed change steps, is not required. Hence costs can be reduced.
The second vehicle acceleration estimation step or device may be constructed such that the vehicle acceleration is estimated when the throttle valve is fully closed.
More specifically, since at the time of descent, the driver desires to travel with the throttle valve fully closed at a constant predetermined acceleration (for example approximately 0), then down slope travelling must be under conditions wherein the driver does not experience a different sensation. Estimation of the vehicle acceleration by the second vehicle acceleration estimation step or device is therefore carried out with the throttle valve fully closed. In this way, the requirements of the driver can be met.
The third speed change control step or device may be constructed to control speed change by selecting a speed change step on the lowest speed side of the speed change steps which gives a vehicle acceleration estimated by the second speed change estimation step or device equal to or above the target acceleration. In this way, a maximum engine braking effect can be applied within a range which is not felt as excessive by the driver.
The construction may be such that at the time of brake operation, speed change control by the third speed change control step or device is not carried out.
More specifically, since vehicle running resistance detection accuracy is reduced when the driver operates the brake, then good final speed change control is lost. Therefore in the case of brake operation, speed change control by the third speed change control step or device is prohibited to avoid this undesirable situation.
Furthermore, the construction may be such that at the time of brake operation, the vehicle running resistance detected by the vehicle running resistance detection step or device, or the target acceleration set by the target acceleration setting step or device, is corrected.
That is to say, when the driver operates the brake, the vehicle running resistance detected by the vehicle running resistance detection step or device, or the target acceleration set by the target acceleration setting step or device is corrected, so that the control accuracy even with brake operation can be improved. In this way, down slope speed change control can be carried out with a more highly accurate third speed change control step or device.
Moreover, the construction may be such that the abovementioned deceleration intention detection step or device detects a situation wherein the engine load is equal to or below a predetermined value, as a deceleration intention of the driver.
That is to say, the operation or condition which can be most quickly detected to reveal the deceleration intention of the driver is the resultant engine load (related for example to the throttle valve opening, amount of accelerator pedal operation, intake air quantity, fuel supply quantity and the like). Hence by detecting the resultant engine load, the deceleration intention of the driver can be most quickly and accurately detected. The down slope speed change control response and accuracy of the first, second, and third speed change control steps or devices can thus be improved.
The construction may be such that the abovementioned target acceleration detection step or device computes a target acceleration based on vehicle conditions.
With this construction wherein the target acceleration is computed based on vehicle conditions, then the target acceleration can be set to a high accuracy corresponding to the vehicle conditions. Hence speed change control for a down slope can be to an even higher accuracy.
The vehicle conditions may include at least one of vehicle speed, vehicle running resistance, and current speed change step. In this way, the target acceleration is set as a parameter which has a large influence on the actual vehicle acceleration. Hence, highly accurate speed change control for a down slope is possible.
Moreover, to cope with the situation wherein the down slope gradient changes along the down slope, then the control for speed change to the down-shift side and the control for speed change to the up-shift side can be combined together to give travelling at the desired acceleration at the time of a down slope.
That is to say, the method and apparatus for controlling the speed change of a vehicle automatic transmission which is connected to an engine output shaft may comprise;
a vehicle speed detection step or device for detecting vehicle speed,
a vehicle running resistance detection step or device for detecting vehicle running resistance,
an engine load detection step or device for detecting engine load,
a deceleration intention detection step or device for detecting a deceleration intention of a driver based on the engine load,
a first vehicle acceleration estimation step or device for estimating vehicle acceleration in the case of a speed change to a speed change step on a lower speed side of a current speed change step, based on the vehicle speed and vehicle running resistance,
a target acceleration setting step or device for setting a target acceleration,
a first acceleration comparison step or device for comparing the vehicle acceleration estimated by the first vehicle acceleration estimation step or device, with the target acceleration set by the target acceleration setting step or device,
a first speed change control step or device for controlling speed change by selecting, at the time of detecting a deceleration intention of the driver by the deceleration intention detection step or device, a speed change step to give a vehicle acceleration after speed change equal to or above the target acceleration, based on the comparison results of the first acceleration comparison step or device,
a vehicle acceleration detection step or device for detecting vehicle acceleration,
a second target acceleration setting step or device for setting a second target acceleration,
a second acceleration comparison step or device for comparing the vehicle acceleration detected by the vehicle acceleration detection step or device, with the second target acceleration set by the second target acceleration setting step or device, and
a second speed change control step or device for controlling speed change from a current speed change step to a speed change step on the higher side, when a deceleration intention of the driver is detected by the deceleration intention detection step or device, and the comparison results of the second acceleration comparison step or device, give the vehicle acceleration detected by the vehicle acceleration detection step or device as less than the second target acceleration.
In this way, even if the down slope gradient changes during down slope speed change control, down-shift control and up-shift control can be carried out to correspond to the gradient change. Therefore good down slope control can be continuously carried out without the driver experiencing any excessive deceleration.
Moreover, in the case of combining together the control for speed change to the down-shift side and the control for speed change to the up-shift side to give travelling at the desired acceleration at the time of a down slope, then the following construction is possible to give an even higher accuracy control.
That is to say, the method and apparatus for controlling the speed change of a vehicle automatic transmission which is connected to an engine output shaft may comprise;
a vehicle speed detection step or device for detecting vehicle speed,
a vehicle running resistance detection step or device for detecting vehicle running resistance,
an engine load detection step or device for detecting engine load,
a deceleration intention detection step or device for detecting a deceleration intention of a driver based on the engine load,
a vehicle acceleration estimation step or device (a combination of the first vehicle acceleration estimation step or device and the second vehicle acceleration estimation step or device) for estimating the current speed change step and vehicle acceleration in the case of speed change, based on the vehicle speed and vehicle running resistance,
a target acceleration setting step or device for setting a target acceleration,
a fourth acceleration comparison step or device for comparing the vehicle acceleration estimated by the vehicle acceleration estimation step or device, with the target acceleration set by the target acceleration setting step or device, and
a fourth speed change control step or device for controlling speed change by selecting, at the time of detecting a deceleration intention of the driver by the deceleration intention detection step or device, a speed change step to give a vehicle acceleration after speed change equal to or above the target acceleration, based on the comparison results of the fourth acceleration comparison step or device.
Accordingly, if the down slope gradient changes during down slope speed change control, then down-shift control and up-shift control can be carried out even more precisely. Therefore exceptionally good down slope control can be continuously carried out without the driver experiencing excessive deceleration.
Further objects and aspects of the present invention will become apparent from the following description of embodiments given in conjunction with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a functional block diagram according to a first aspect of the present invention;
FIG. 2 is a functional block diagram according to a second aspect of the present invention;
FIG. 3 is a functional block diagram according to a third aspect of the present invention;
FIG. 4 is a system diagram according to a first embodiment;
FIG. 5 is a flow chart (first flow chart) for explaining a down slope speed change control routine according to the first embodiment;
FIG. 6 is a flow chart (second flow chart) for explaining the down slope speed change control routine according to the first embodiment;
FIG. 7 is a graph showing an example of an R/L (air resistance plus rolling resistance) table;
FIG. 8 is a graph showing an example of a Tt (turbine torque retrieval) map;
FIG. 9 is a graph showing an example of a TRA table (for computing down-shift or up-shift target acceleration):
FIG. 10 is a graph for explaining a normal speed change pattern;
FIG. 11 is a system diagram according to a second embodiment;
FIG. 12 is a flow chart for explaining a down slope speed change control routine according to the second embodiment;
FIG. 13 is a flow chart (first flow chart) for explaining a down slope speed change control routine according to a third embodiment;
FIG. 14 is a flow chart (second flow chart) for explaining the down slope speed change control routine according to the third embodiment;
FIG. 15 is a flow chart (first flow chart) for explaining a down slope speed change control routine for a case wherein the first embodiment and the second embodiment are combined together;
FIG. 16 is a flow chart (second flow chart) for explaining the down slope speed change control routine for the case wherein the first embodiment and the second embodiment are combined together;
FIG. 17 is a flow chart (first flow chart) for explaining a down slope speed change control routine for a case wherein the first embodiment and the third embodiment are combined together;
FIG. 18 is a flow chart (second flow chart) for explaining the down slope speed change control routine for the case wherein the first embodiment and the third embodiment are combined together;
FIG. 19 is a flow chart (third flow chart) for explaining the down slope speed change control routine for the case wherein the first embodiment and the third embodiment are combined together; and
FIG. 20 is a map for setting speed change timing in accordance with a speed change step, according to a conventional example.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As follows is a description of embodiments of the present invention with reference to the drawings.
With a first embodiment as shown in FIG. 4, an engine 1 is connected to an automatic transmission 2 whereby the generated torque of the engine 1 is transmitted to a vehicle drive wheel (not shown in the figure). The automatic transmission 2 comprises a torque converter 3 into which the torque generated by the engine 1 is input through the medium of a fluid, a multi-step type speed change gear mechanism 4 into which the output of the torque converter 3 is input to give a speed change output, and an oil pressure mechanism (not shown) for driving the speed change gear mechanism 4.
Solenoid valves 6A, 6B are assembled inside the oil pressure mechanism of the speed change gear mechanism 4. By switching open/close combinations of the solenoid valves 6A, 6B, engaged/disengaged combinations of respective clutches incorporated in the speed change gear mechanism 4 are changed, to thereby effect speed change to a desired speed change step.
On/off control of the plurality of solenoid valves is carried out based on control signals from a control unit 50 which comprises a CPU, ROM, RAM, A/D converter, input output interface and so on.
Signals from various sensors are input to the control unit 50. For the various sensors there is provided, a throttle valve sensor 7 serving as an engine load detection device which generates an output signal corresponding to the throttle valve opening TVO, and a vehicle speed sensor 8 serving as a vehicle speed detection device which detects a rotational speed of an output shaft 5 of the automatic transmission 2, and outputs a vehicle speed VSP.
The functions of a vehicle running resistance detection device, deceleration intention detection device, first vehicle acceleration estimation device, target acceleration setting device (first target acceleration setting device), first acceleration comparison device, and first speed change control device, are realized by software stored in the control unit 50. A description of speed change control carried out by the control unit 50 for a down slope is given hereunder with reference to the flow charts of FIGS. 5 and 6. A schematic functional block diagram depiction of the operation of the first embodiment is also given in FIG. 1.
In step 1 (with step indicated by S in the figures), vehicle speed VSP and throttle valve opening TVO are detected.
Then in step 2, a current acceleration resistance (RESI-A) is obtained. The current acceleration resistance (RESI-A) can be obtained from the following equation:
RESI-A=ALF×k α
where: ALF is the current acceleration, and k α is an acceleration resistance computation constant (set according to vehicle weight and the like).
In step 3, RESI-RL (air resistance+rolling resistance) is computed from the vehicle speed VSP and an R/L table (air resistance+rolling resistance computation table; see FIG. 7).
In step 4, a current turbine rotational speed (Nt, ie. torque converter 3 output shaft rotational speed) is obtained. The turbine rotational speed (Nt) may be obtained from the following equation:
Nt=VSP×k Nt (g)
where: kNt (g) is a constant determined from the current speed change step, g being the current speed change step.
The current speed change step may be detected by providing a gear position sensor in the speed change gear mechanism 4, to detect the speed change position. However, determining the speed change step from a current speed change indication signal of the control unit 50 has a cost wise advantage.
In step 5, the current turbine torque (Tt, ie. torque converter 3 output shaft torque) is obtained from a vehicle speed VSP and turbine torque Tt map (a three dimensional map of Nt, TVO, and Tt; see FIG. 8).
In step 6, a current drive force (FCE) is obtained from the following equation:
FCE=Tt×k Tt (g)
where: k Tt (g) is a constant determined from the current speed change step, g being the current speed change step.
In step 7, the running resistance (RESI-I) is obtained from the following equation:
RESI-I=(FCE)-(RESI-RL)-(RESI-A)
In step 8, TGT-RA is computed from the vehicle speed VSP and a TRA table (TGT-RA computation table, see FIG. 9; TGT-RA is the "down-shift target acceleration"). The "down-shift target acceleration", for example with the present embodiment, this is preferably set in relation to step 19 (to be described later) for preventing excessive deceleration, to an acceleration which results in an excessive deceleration. Of course the down-shift target acceleration may be a value such that the desired deceleration characteristics after speed change are finally obtained. Moreover, the down-shift target acceleration may be a fixed value. However if this is set as with the present embodiment, corresponding to vehicle speed (or vehicle running resistance, current speed change step etc.), then the target acceleration can be set to a higher accuracy, resulting in high accuracy speed change control.
Step 8 constitutes the target acceleration setting device.
In step 9, a speed change step i after down-shift (=g-1, g being the current speed change step) is obtained.
In step 10, it is judged if i is zero. If so (0), then control proceeds to step 11, while if not (1), control proceeds to step 12.
In step 11, since the current speed change step is the first speed (speed 1), then further down-shift is not possible. The current instruction to the control unit 50 to select speed 1 is therefore maintained.
In step 12, since the current speed change step is not speed 1, down-shift is possible if required. The turbine rotational speed Nt2 for the case of down-shift is therefore obtained from the following equation:
Nt2=VSP×k Nt (i)
where: k Nt (i) is a constant determined for the speed change step after down-shift.
In step 13, the turbine torque (Tt2) for the case of down-shift is obtained from the vehicle speed VSP and the turbine torque Tt map.
In step 14, a drive force (FCE2) for the case of down-shift is obtained from the following equation:
FCE2=Tt2×k Tt (i)
where: k Tt (i) is a constant determined for the speed change step after down-shift.
In step 15, the acceleration resistance (RESI-A2) for the case of down-shift is obtained from the following equation:
RESI-A2=(FCE2)-(RESI-I)-(RESI-RL)
In step 16, the acceleration resistance (RESI-A2) for the case of down-shift, and the down-shift target acceleration (TGT-RA) are compared.
If the acceleration resistance (RESI-A2) is greater than or equal to the down-shift target acceleration (TGT-RA), then in step 17 the current i is set to g, and control then returns to step 9 to re-compute an acceleration resistance (RESI-A2) for the case of down-shift.
On the other hand, if the acceleration resistance (RESI-A2) is less than the down-shift target acceleration (TGT-RA), then a speed change step which gives an acceleration less than the down-shift target acceleration (for example excessive deceleration) has been found. Control therefore proceeds to step 18 where the deceleration (coasting) intention of the driver is verified, as materials to determine if down shift is to be actually carried out.
In step 18, it is judged if the throttle valve opening TVO is less than or equal to a deceleration intention judgment opening (TVO-cnst). With this deceleration intention judgment opening (TVO-cnst), a setting for example of fully closed is the closest to a deceleration intention of the driver. If engine load can be detected, then the deceleration intention of the driver can be judged from the amount of accelerator operation or the basic fuel injection pulse width Tp and so on. Without using a signal from the throttle valve sensor 7 as in the present embodiment, the presence or absence of a deceleration intention of the driver can be judged from a signal from an idle switch which produces an ON signal in the fully closed condition.
If the judgment of step 18 is YES (TVO≦TVO-cnst), this indicates that the driver intends to decelerate. Control therefore proceeds to step 19 to carry out actual down-shift.
If the judgment of step 18 is NO (TVO>TVO-cnst), this indicates that the driver does not intend to decelerate. Forcible down-shift control for the down slope is therefore not carried out in order to respect the will of the driver and avoid giving a different sensation. The flow control is therefore terminated, and speed change control is carried out according to the normal speed change pattern (FIG. 10).
In step 19, since the driver actually intends to decelerate, then a speed change step (=i+1) with a "1" added to the presently set speed change step i for the case of down-shift is selected to send a speed change instruction to the control unit 50, and the flow control terminated. In this way, down-shift is carried out to a speed change step one step higher than the speed change step for excessive deceleration. It is thus possible to obtain good deceleration characteristics corresponding to the gradient without the driver experiencing a different sensation of an excessive engine braking effect. Hence the vehicle drivability on a down slope can be improved.
In this way, the acceleration resistance (RESI-A2) for the case of down-shift, and the down-shift target acceleration (TGT-RA) are compared in step 16, and when a speed change step wherein an acceleration for the case of down-shift is an excessive deceleration is found, then (in step 19) a speed change step on the higher speed side of the found speed change step is selected. Hence, effectively, a speed change step which gives a vehicle acceleration after speed change equal to or above the down-shift target acceleration (that is to say does not give excessive deceleration) is always selected. Therefore speed change control on a down slope can be reliably carried out without the driver experiencing a different sensation of an excessive engine braking effect.
This point is important since if the driver experiences even a slight excess deceleration, since the driver has no effective means to avoid this different sensation, it cannot be overcome. However, if a speed change step is selected to give a vehicle acceleration after speed change close to and above the target acceleration value, then for example even if the driver experiences this as a different sensation, since this will be one of excess acceleration, it can very easily overcome by applying the brake.
In this way, with the first embodiment, the acceleration resistance (RESI-A) for the case of down-shift, and the down-shift target acceleration (TGT-RA) are compared, and speed change is effected by selecting a speed change step which is one step higher than the speed change step giving excessive deceleration, so that the driver does not experience a difference sensation of excess deceleration. At this time, it is judged if there is a deceleration intention of the driver, based on the throttle valve operation (throttle valve opening TVO). In the case of no deceleration intention, forcible down-shift control for the down slope is prohibited in order to respect the will of the driver and avoid giving a different sensation, and speed change control is carried out according to the normal speed change pattern. Only in the case of a deceleration intention, is speed change to a speed change step one step higher than the speed change step giving excessive deceleration carried out. It is therefore possible to obtain good deceleration characteristics corresponding to the gradient, without the driver experiencing any different sensation of an excessive engine braking effect. Hence the vehicle drivability on a down slope can be optimized.
With the present embodiment, since speed change can be reliably carried out to a speed change step for an acceleration which does not give excessive deceleration (for example a value close to and above 0), the undesirable situation wherein the driver experiences a sensation of excessive deceleration, that is to say a continuing different sensation which cannot be overcome because the driver has no effective means for avoiding this, is not produced. Hence, with the present embodiment for example, even if the driver experiences a different sensation, since this is one of excess acceleration, it can be very easily overcome by applying the brake. The continuing different sensation experienced by the driver can therefore be stopped.
Furthermore, with the present embodiment, since the vehicle acceleration is estimated by computation and compared with the target acceleration to thereby select the speed change step, then a map requiring a large memory, as with the conventional arrangement (see FIG. 20) wherein the speed change timing is set in accordance with the speed change steps, is not required. Hence costs can be reduced.
Furthermore, since at the time of descent, the driver desires to travel with the throttle valve fully closed at a constant predetermined acceleration (for example approximately 0), then to correspond to this situation, estimation of the vehicle acceleration for the case of down-shift is preferably carried out with the throttle valve fully closed. In this way, more accurate down slope speed change control can be carried out to meet the requirements of the driver.
A description of a second embodiment will now be given.
With the first embodiment speed change was carried out to the down-shift side to enable travelling at a desired acceleration at the time of decent. However with the second embodiment speed change is carried out to the up-shift side to enable travelling at a desired acceleration at the time of decent.
That is to say, the second embodiment deals with the situation when the down slope gradient is gentle, or when the current speed change step is on the low side, and the driver will experience a different sensation of excess deceleration if up-shift is not carried out. A schematic functional black diagram depiction of the operation of this embodiment is also given in FIG. 2.
The overall construction (system arrangement) of the second embodiment as shown in FIG. 11, is similar to that of the first embodiment with the exception of a brake switch 10 which sends an ON signal to the control unit 50 when the foot brake is pressed, and hence detailed description is omitted.
The functions of a deceleration intention detection device, vehicle acceleration detection device, target acceleration setting device (second target acceleration setting device), second acceleration comparison device, and second speed change control device, are realized by software stored in the control unit 50. A description of speed change control carried out by the control unit 50 is given hereunder with reference to the flow chart of FIG. 12.
In step 21, vehicle speed VSP and throttle valve opening TVO are detected.
Then in step 22, a current acceleration resistance (RESI-A) is obtained. The current acceleration resistance (RESI-A) can be obtained from the following equation:
RESI-A=ALF×k α
where: ALF is the current acceleration, and k α is an acceleration resistance computation constant (set according to vehicle weight and the like).
In step 23, TGT-RA is computed from the vehicle speed VSP and the TRA table (TGT-RA computation table, see FIG. 9; here TGT-RA means the "up-shift target acceleration"). The "up-shift target acceleration", may be a value such that the desired deceleration characteristics (greater than and close to zero) are obtained. Moreover, the up-shift target acceleration may be a fixed value. However if this is set as with the present embodiment, corresponding to vehicle speed (or vehicle running resistance, current speed change step etc.), then the target acceleration can be set to a higher accuracy, resulting in high accuracy speed change control.
In step 24 it is judged if the brake switch 10 is ON. If so, control proceeds to step 25, while if not, control proceeds to step 26.
In step 25, a correction term β for when the brake is pressed, is added to the obtained up-shift target acceleration TGT-RA (TGT-RA+β→TGT-RA). Alternatively, RESI-A may be corrected.
In step 26, the current acceleration resistance (RESI-A), and the up-shift target acceleration (TGT-RA) are compared.
If the acceleration resistance (RESI-A) is greater than or equal to the up-shift target acceleration (TGT-RA), then the required acceleration has been obtained. The flow control is therefore terminated, and speed change control is carried out according to the normal speed change pattern (FIG. 10).
On the other hand, if the acceleration resistance (RESI-A) is less than the up-shift target acceleration (TGT-RA), then since deceleration will be excessive, it is necessary to up-shift to a speed change step which is one step higher than the current speed change step. However to verify the deceleration (coasting) intention of the driver, as materials to determine if up-shift is to be actually carried out, control proceeds to step 27.
In step 27, it is judged if the throttle valve opening TVO is less than or equal to a deceleration intention judgment opening (TVO-cnst).
If YES (TVO≦TVO-cnst), this indicates that the driver intends to decelerate. Control therefore proceeds to step 28.
If NO (TVO>TVO-cnst), this indicates that the driver does not intend to decelerate. Forcible up-shift control for the down slope is therefore not carried out in order to respect the will of the driver and avoid giving a different sensation. The flow control is therefore terminated, and speed change control is carried out according to the normal speed change pattern (FIG. 10).
In step 28, since the driver intends to decelerate (coast), then a speed change instruction is sent to the control unit 50 to up-shift to a speed change step which is one step higher than the current speed change step, and the flow control terminated. In this way, excessive deceleration with travelling in the current speed change step can be prevented. It is thus possible to obtain good deceleration characteristics corresponding to the gradient without the driver experiencing a different sensation of an excessive engine braking effect. Hence the vehicle drivability on a down slope can be improved. Of course, in the case of a 1-step up-shift when the current speed change step is the highest speed change step, then since further up-shift is not possible, the highest speed change step is maintained.
In this way, with the second embodiment, the current acceleration resistance (RESI-A), and the up-shift target acceleration (TGT-RA) are compared, and if in the current speed change step, the driver will experience excessive deceleration, then before up-shift to a speed change step which is one step higher than the current speed change step, it is judged if there is a deceleration (coasting) intention of the driver, based on the throttle valve operation (throttle valve opening TVO). In the case of no deceleration intention, forcible up-shift control for the down slope is prohibited in order to respect the will of the driver and avoid giving a different sensation, and speed change control is carried out according to the normal speed change pattern. On the other hand, in the case of a deceleration intention, up-shift to a speed change step one step higher than the current speed change step giving excessive deceleration is carried out. It is therefore possible with a simple construction to obtain good deceleration characteristics corresponding to the gradient, without the driver experiencing any different sensation of an excessive engine braking effect. Hence the vehicle drivability on a down slope can be optimized. The point that the driver does not experience excessive deceleration is the same as with the beforementioned first embodiment.
Furthermore, with the present embodiment also, since the speed change step is selected by computation, then a map requiring a large memory, as with the conventional arrangement (see FIG. 20) wherein the speed change timing is set in accordance with the speed change steps, is not required. Hence costs can be reduced.
With the second embodiment, it is judged if the brake is being pressed, and if being pressed, the current acceleration resistance or the target acceleration is corrected. Worsening of the speed change control due to pressing of the brake can thus be prevented. Alternatively, when the driver presses the brake, the down slope speed change control can be prohibited to thus prevent the driver experiencing a different sensation with the worsening of the speed change control due to pressing of the brake. Furthermore, the down slope speed change control can be carried out irrespective of pressing of the brake although there is a slight drop in accuracy. That is to say a construction with steps 24 and 25 omitted is also possible.
A third embodiment will now be described.
The third embodiment, is aimed at increasing the accuracy of the second embodiment, and deals with the situation when the down slope gradient is gentle, or when the current speed change step is on the low side, and the driver will experience a different or disconcerting sensation of excess deceleration if up-shift is not carried out.
The overall construction (system arrangement) of the third embodiment, is similar to that of the first embodiment, and hence description is omitted.
The functions of a deceleration intention detection device, vehicle running resistance detection device, second vehicle acceleration estimation device, target acceleration setting device (third target acceleration setting device), third acceleration comparison device, schematically depicted in functional black diagram form in FIG. 3, and third speed change control device, are realized by software stored in the control unit 50. A description of speed change control carried out by the control unit 50 is given hereunder with reference to the flow charts of FIGS. 13 and 14.
In step 31, vehicle speed VSP and throttle valve opening TVO are detected.
Then in step 32, the current acceleration resistance (RESI-A) is obtained in the same manner as before.
In step 33, RESI-RL (air resistance+rolling resistance) is computed from the vehicle speed VSP and the R/L table (see FIG. 7).
In step 34, the current turbine rotational speed Nt is obtained in the same manner as before.
In step 35, the current turbine torque Tt is obtained from the vehicle speed VSP and the turbine torque Tt map (see FIG. 8).
In step 36, the current drive force FCE (=Tt×k Tt (g)) is obtained in the same manner as before.
In step 37, the running resistance RESI-I (=(FCE)-(RESI-RL)-(RESI-A)) is obtained in the same manner as before.
In step 38, TGT-RA is computed from the vehicle speed VSP and the TRA table (TGT-RA computation table, see FIG. 9; here TGT-RA means the "up-shift target acceleration"). The "up-shift target acceleration", may be a value such that the desired deceleration characteristics (greater than and close to zero) are obtained. Moreover, the up-shift target acceleration may be a fixed value. However if this is set as with the present embodiment, corresponding to vehicle speed (or vehicle running resistance, current speed change step etc.), then the target acceleration can be set to a higher accuracy, resulting in high accuracy speed change control.
Step 38 constitutes the target acceleration setting device or the second target acceleration setting device.
In step 39, the current speed change step is made i.
In step 40 it is judged if the currently set i is "5". If so, then control proceeds to step 41, while if not, control proceeds to step 42. Since the present embodiment is concerned with a fourth speed speed changer, it is not possible to speed change to a fifth speed. Hence in step 40 it is judged if i is a "5". In this respect, the judgment value (upper limit+1) is appropriately modified to correspond to the number of speed change steps of the speed changer in the vehicle.
In step 41, the fourth speed (speed 4) is selected and the flow control then terminated.
In step 42, the turbine rotational speed Nt2 for the currently set step i is obtained from the following equation:
Nt2=VSP×k Nt (i)
where k Nt(i) is a constant determined for the speed change step i.
In step 43, the turbine torque (Tt2) for the speed change step i, is obtained from the vehicle speed VSP and the turbine torque Tt map.
In step 44, a drive force (FCE2) for the speed change step i is obtained from the following equation:
FCE2=Tt2×k Tt (i)
where: k Tt (i) is a constant determined for the speed change step i.
In step 45, the acceleration resistance (RESI-A2) for the currently set speed change step i is obtained from the following equation:
RESI-A2=(FCE2)-(RESI-I)-(RESI-RL)
In step 46, the acceleration resistance (RESI-A2) for the currently set speed change step i, and the up-shift target acceleration (TGT-RA) are compared.
If the acceleration resistance (RESI-A2) is less than the up-shift target acceleration (TGT-RA), the required acceleration is not obtained (excessive deceleration). Control therefore returns to step 40 to give an up-shift, after first setting i to i+1 in step 47.
On the other hand, if the acceleration resistance (RESI-A2) is greater than or equal to the up-shift target acceleration (TGT-RA), then a speed change step which gives an acceleration greater than or equal to the up-shift target acceleration (which does not give excessive deceleration) has been found. Control therefore proceeds to step 48 where the deceleration (coasting) intention of the driver is verified, as materials to determine if down shift is to be actually carried out.
In step 48, it is judged if the throttle valve opening TVO is less than or equal to a deceleration intention judgment opening (TVO-cnst).
If the judgment of step 48 is YES (TVO≦TVO-cnst), this indicates that the driver actually intends to decelerate. Control therefore proceeds to step 49. In step 49, a signal is sent to the control unit 50 to up-shift to the speed change step i set in the beforementioned step so that deceleration is not excessive, and the flow control is terminated.
If the judgment of step 48 is NO (TVO>TVO-cnst), this indicates that the driver does not intend to decelerate. Forcible up-shift control for the down slope is therefore not carried out in order to respect the will of the driver and avoid giving a different sensation. The flow control is therefore terminated, and speed change control is carried out according to the normal speed change pattern (FIG. 10).
In this way, with the third embodiment, speed change is carried out by comparing the acceleration resistance (RESI-A2) for the case of up-shift, with the up-shift target acceleration (TGT-RA) to select a speed change step which gives a desired acceleration without excessive deceleration at the time of down slope coasting. At this time, it is judged if there is a deceleration intention of the driver, based on the throttle valve operation (throttle valve opening TVO). In the case of no deceleration intention, forcible up-shift control for the down slope is prohibited in order to respect the will of the driver and avoid giving a different sensation, and speed change control is carried out according to the normal speed change pattern. Only in the case of a deceleration intention, is the beforementioned speed change control carried out. It is therefore possible to obtain good deceleration characteristics corresponding to the gradient, without the driver experiencing any different sensation of an excessive engine braking effect. Hence the vehicle drivability on a down slope can be optimized.
Furthermore, with the present embodiment also, since the speed change step is selected by computation, then a map requiring a large memory, as with the conventional arrangement (see FIG. 20) wherein the speed change timing is set in accordance with the speed change steps, is not required. Hence costs can be reduced.
Since at the time of descent, the driver desires to travel with the throttle valve fully closed at a constant predetermined acceleration (for example approximately 0), then to correspond to this situation, estimation of the vehicle acceleration for the case of up-shift is preferably carried out with the throttle valve fully closed. In this way, more accurate down slope speed change control can be carried out to meet the requirements of the driver.
The abovementioned respective embodiments, have been described in relation to arrangements wherein down-shift control or up-shift control is carried out separately to obtain a desired acceleration at the time of down slope coasting. However in the case where the gradient of the down slope changes along the down slope, good acceleration control cannot be obtained since with down-shift control there is no up-shift and with up-shift control there is no down-shift. Therefore, to carry out even better control, a construction is preferable wherein the down-shift control and up-shift control are combined together as shown for example in FIGS. 15 and 16 (an example with the first and second embodiments combined) and FIGS. 17 through 19, (an example with the first and third embodiments combined).
Moreover, with the above respective embodiments, the deceleration intention of the driver is detected. The operation or condition which can be most quickly detected to reveal the deceleration intention of the driver is the engine load (related for example to the throttle valve opening, amount of accelerator pedal operation and the like). Hence by detecting the engine load, the deceleration intention of the driver can be most quickly and accurately detected. Therefore, the accuracy of speed change control at the time of a down slope can be increased.
With the first and the third embodiments there is no judgment for pressing of the brake as with the second embodiment. However these embodiments can be modified so that, as with the second embodiment, when the brake is pressed, the vehicle running resistance (RESI-A) or the target acceleration is corrected so as to prevent worsening of the speed change control due to pressing of the brake. Alternatively, when the driver presses the brake, the down slope speed change control can be prohibited to thus prevent the driver experiencing a different sensation with the worsening of the speed change control due to pressing of the brake. | A down-shift acceleration resistance and a down-shift target acceleration are compared, and only when a deceleration intent by the driver is detected, is a down-shift to a gear ratio which is one step higher than a gear ratio which will produce deceleration in excess of that indicated necessary by the comparison, permitted. In the absence of any detected deceleration intent by the driver, a forcible downshifting is inhibited. The shifting is controlled through computation which does not rely on large amounts of prestored table data. | 5 |
BACKGROUND OF THE INVENTION
The invention relates to underground mining in general and more particularly to an arrangement for controlling advancing timbering.
For adapting to the progress of a mine being worked by means of a mining machine, the timbering units, for instance, the timber frames, are equipped with hydraulic cylinders which must fulfill the following functions: Drawing the timbering, pushing the timbering forward, setting the timbering, advancing the conveyer and, optionally, extending the support cars. These functions can be triggered via, for instance, electromagnetically operated valves from a longwalling control room or also at the site. A longwall timbering system comprises a number of timbering units which can be controlled individually or by groups to obtain the advancing process.
An arrangement for controlling advancing timbering in underground mines comprising: a plurality of control units, one assigned to each timbering units, which can be selected individually and each of which contain an electronic evaluation circuit; and a control room (or central control) which is equipped with a system which transmits control data delivered by a computer serially to the control units, is also equipped with a device indicating the state of the timbering, and with an input device for selecting the computer program, is described in DE-OS No. 27 36 365.* In the disclosed system, the control units are built up from electronic components and connected to the computer in the control room via a cable with a multiplicity of conductors, to each of which a task is assigned such as data transmission, power supply, timing, etc. This design of the control units is expensive, and due to the parallel connection to the cable, which is common to all control units, in the case of trouble it is difficult to determine at which control unit or in which cable section the trouble has occurred.
It is an object of the present invention to produce a system for the control for longwall timbering in such a manner that the control data can be transmitted at the lowest possible cost without interference, and operating disturbances can be localized without elaborate measures.
SUMMARY OF THE INVENTION
According to the present invention, this problem is solved by connecting a first receiver which is arranged in each control unit and receives the control data, to the evaluation circuit and to a first transmitter which is connected via a control line to the first receiver of the immediately following control unit. A second transmitter in each control unit, delivers acknowledgment messages and is connected via a further line to a second receiver of the respective, immediately preceding control unit. The second transmitter can be connected via a switch to the evaluation circuit or to the second receiver of the control unit. The first receiver of the first control units is coupled to the central control as is the second transmitter of this first control unit.
With this design, short and uniform line sections between the individual control units are obtained. Since the control data are passed on sequentially from one control unit to the other and similarly, the acknowledgment messages in the opposite direction, trouble occurring on the transmission path can readily be localized.
Advantageously, the evaluation circuit includes a minicomputer, converters connected thereto for the parallel to serial and serial to parallel transmission of the control and acknowledgment data, and control logic. So that transmission of control data from one control unit to the immediately adjacent control units is possible if a disturbance in the control room or in the transmission channel leading to the control room occurs, each control unit contains, according to a further feature of the present invention, a third receiver for initiating data traffic between the control units of two adjacent timbering units, independent of the control room. Two further transmitters which can be connected to the evaluation circuit via a second switch, and two further receivers which can be connected to the evaluation circuit via a third switch, where the further transmitters are connected via a further line each to the corresponding further receiver of the adjacent control unit, form a second transmission path, independent of the control room.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a first embodiment according to the present invention.
FIG. 2 is a block diagram of a second embodiment according to the present invention.
DETAILED DESCRIPTION
As shown in FIG. 1, a control room 1 and control units A1 to An for respective timbering units are provided for remotely controlling a face support. In the control room 1, a computer 2 is arranged, which is connected to an input unit 3, for instance, a keyboard, for calling up one of the control programs stored in the computer. The computer furnishes the control data corresponding to the selected program via a parallel to serial converter 4 to a transmitter 5. A receiver 6 receives the acknowledgment data arriving from the control units and transmits it via a serial to parallel converter 7 to the computer which evaluates this data and feeds signals characterizing the operating state of the timbering and walling to a display device 8.
According to FIG. 1, each of the control units contains five transmitters S1 to S5, five receivers E1 to E5 and one evaluation circuit 9 which comprises a minicomputer 10 with serial to parallel converters 11 and 12, parallel to serial converters 13 and 4, control logic 15 and supervisory logic 16. Switches 17, 18 and 19 are operated by the computer 10 via the control logic 15. The minicomputer 10 further addresses magnetic valves 20, with which the hydraulic drives of the timbering unit for causing the advancing processes, are associates. The advancing processes are monitored by sensors which deliver corresponding signals to the minicomputer. The sensors and a further keyboard for selecting programs at the site are indicated by the block 21.
The control data corresponding to the program selected by means of the keyboard 3, which consists of an address characterizing an individual control unit, an information part and a security part, is transmitted by the computer 2 in the control room to the parallel to serial converter 4 to be passed on to the transmitter 5. Transmitter 5 is connected via a control line 22 to the first receiver E1 of the control unit A1. The receiver E1 transfers the control data via the serial to parallel converter 11 to the minicomputer 10 and simultaneously to the first transmitter S1 of the control unit A1. The transmitter S1 of each of the control units other than the last one, i.e., the nth, is connected to the receiver E1 of the respective following control unit via a further control line 23. The control data delivered by the computer 2 is therefore passed on from one control unit to the next following one. The minicomputer 10 of each control unit examines the control data for its content. The minicomputer 10 of that control unit, the address of which agrees with the address given in the control data, operates its switch 17 via the control logic 15 and sends acknowledgment data to the control room via the transmitter S2. The control units which are not addressed receive the acknowledgement data delivered by the control unit selected from the transmitter S2 via their receiver E2 and pass on the data without further evaluation (with switch 17 in the position shown), via their transmitter S2 and a control line 24, to the receiver E2 of the respective preceding control unit until the first control unit A1 sends it to the control room. For this purpose, the transmitter S2 of the control unit A1 is connected via a control line 25 to the receiver 6 of the control room, which transmits the acknowledgment data to the computer 2 via the serial to parallel converter 7. The acknowledgment data is therefore passed on in the same manner as the control data from one control unit to the other. Thereby, faults occurring on the transmission path can be localized without difficulty and the line sections 23 and 24 always have the same length. The transmitters represent switchable voltage or current sources, while opto-electronic coupling elements are employed as receivers. The relatively short line sections (the distance between two control units is about 3 m) are terminated with low impedance and therefore ensure interference free data transmission.
As already mentioned, the minicomputer 10 of the addressed control unit, for instance, A2, delivers via the parallel to serial converter 13 and the switch 17, now switched to the other position, acknowledgment data to the transmitter S2 which passes on the data via the receiver E2, the switch 17 and the transmitter S2 of the preceding control unit, for instance A1, to the receiver 6 of the control room. The computer 2 in the control room checks the acknowledgment data and, in the event of an error, outputs the original control data again. If the acknowledgment data fails to arrive, the computer decides that there is a fault.
Since the control units A1 to An are called up cyclically in sequence, the number of the individual controls included in the transmission path and of the connecting lines increases in a defined manner. It is thereby possible to simplify troubleshooting in the event of a disturbance. A further possibility for localizing faults is provided by a test facility 29 which monitors the outputs of the receivers E1 and E2 in each control unit and contains, for instance, light-emitting diodes for indicating faults.
The receivers E1 and E2 and the transmitters S1 and S2 of each of the control units are reserved, in FIG. 1, for the exchange of data between the control room and the individual control units. So that the control units can conduct a data exchange with the control units of the respective adjacent timbering units regardless of the cyclic call-up by the control room, each control unit is equipped with further transmitters S3 to S5 and further receivers E3 to E5 as well as with a separate keyboard. If the control units do not receive control data from the control room for an extended period of time, then they switch automatically to operation without the control room. To operate the control units at the site, a program stored in the minicomputer, for instance, is called up via the keyboard. The minicomputer of the selected control unit, for instance, A2, then furnishes a request to receive to the receiver E3 of the control unit preceding in the sequence, via the corresponding transmitter S3 and the connecting line 26, for instance, A1, which in turn switches the minicomputer of the control unit A1 to a state of receiving readiness for receiving from the adjacent timbering (in the example, A2). The minicomputer of the selected control unit, for instance, A2, then feeds, via the parallel to serial converter 14, the switch 19, the transmitter S5 and the line 27, control data to the receiver E5 of the preceding control unit, for instance, A1, the control logic 15 of which has switched over the switch 18 due to the receiving readiness of the minicomputer, so that the received control data arrives via the serial to parallel converter 12 at the minicomputer of the control unit A1. The minicomputer 10 of the control unit A1 feeds back acknowledgement data to the receiver E4 of the control unit A2 via the parallel to serial converter 14, the switch 19 which has likewise been switched over by the control logic, the transmitter S4 and the line 28. The acknowldgment data reaches the minicomputer via the switch 18, which is not switched over, and the serial to parallel converter 12 of the control unit A2. Each control unit grants priority to the reception of control data of the immediately preceding control unit. However, it is also possible to select with the keyboard a program which makes available, via the parallel to serial converter 14, the switch switched over by the control logic, the transmitter S4 and the receiver E4, a transmission path from a preceding control unit to the control unit following in the sequence. In this manner, every control unit can exchange data with the neighbor or neighbors to the left or right without utilizing the data transmission system of the control room. To the control logic 15 of each control unit is added monitoring logic 16 which takes over the security functions in the event of a failure of the minicomputer and ensures that the control data, outputted by the control room, of the right-hand neighbor is passed on, via the transmissions paths 23 and 24.
The control arrangement according to FIG. 2 differs from the one shown in FIG. 1 essentially by the feature that "operation with control room" or "operation without control room" is preselected from the control room and that only the lines 23 and 24 are used for the cyclic call up of the control units A1 to An by the control room as well as for the data exchange of the control units with the respective adjacent control units if the control room fails. For this purpose, the control room contains a further transmitter 36 which is connected via a control line 30 to a receiver E6 in the control unit A1 which is directly connected to the control room. Transmitter 36 transmit the chosen mode of operation to the minicomputer 10 of the control unit A1 through receiver 6. The chosen mode of operation is simultaneously transmitted by the transmitter S6 via the control line 37, to the receiver E6 of the following control unit, etc. The minicomputer 10 of the control units A2 to An then can, as described in connection with the embodiment according to FIG. 1, deliver a receiving request to the receiver E3 of the respective preceding control unit. A further difference is that, in every control unit, the receiver E1 is connected to the serial to parallel converter 11 through a switch 35 and to the transmitter S1 through switches 31 and 32 in series. In an analogous manner, the receiver E2 is connected to the transmitter S2 through switches 33 and 34 in series and to the serial to parallel converter through the switch 35. Control logic 15 controls switch 35. In the rest position of the switches 31 to 35 shown in the drawing, the receiver E1 transmits the arriving control data to the transmitter S1 of the control unit and at the same time it is coupled via the serial to parallel converter 11 to the minicomputer 10 of the control unit. The transmitter S1 of the control unit A1 passes the control data to the receiver E1 of the control unit A2, and so forth, until finally the control data reaches the control unit An.
In each of the control units, the control data is decoded. The control unit, the address of which agrees with the address contained in the control data, sends acknowledgment data to the control room. The control units which are not addressed pass the signals received via the receiver E2 in the respective control unit following in the sequence and its transmitter S2 directly to the control unit preceding in the sequence. To this end, the minicomputer of the addressed control unit switches the switches 33 and 34 via the control logic 15 in such a way that the data to be sent is coupled to the transmitter S2 through the parallel to serial converter 13. The transmitter S2 transmits the data processed by the computer to the receiver E2 of the respective preceding, not addressed, control unit, which passes on the data without examination to the control unit preceding it until, finally, the receiver 6 in the control room accepts the data. If "operation without control room" is set via the transmitter 36, then all control units are switched over to this mode of operation. If the control line 30 is interrupted, the control lines automatically recognize the mode of operation "operation without control room". In this case the transmission from and to the control room is inhibited, and every control unit can start a data exchange with its neighbors via the connecting lines 23 and 24 to the adjoining control units.
After being switched to "operation without control room", the minicomputer in each control unit first operates the switches 31 and 33 in such a manner, via the control logic, that the transmitters S1 and S2 are switched off and deliver only a rest signal. The switches 32 and 34 and 35 retain their rest position shown. Thereby, the minicomputer is ready to receive control data from the respective preceding control unit. If control data arrives from the preceding control unit, the computer of the receiving control unit can connect the transmitter S2 via the switches 33 and 34, which can be operated by the control logic, to the parallel to serial converter 13 and send acknowledgment data.
If a receiving request is delivered by the transmitter S3 to the preceding control unit, then the minicomputer of this control unit couples the receiver E2 via the switch 35 to the serial to parallel converter 11 and is therewith ready to receive. For sending acknowledgement data, the transmitter S1 is connected via the switches 31 and 32 to the parallel to serial converter 13.
For sending control data from one control unit to the next following one, a request to receive is not necessary. The minicomputer of the following control unit receiving the control data establishes, via the control logic and the switches 33 and 34, the connection between the transmitter S2 and the parallel to serial converter 13. | A system for advancing timbering in underground mines comprises a number of longwall supporting timbering units which are pushed forward hydraulically in accordance with the progress of the working obtained by a mining machine, along with a conveyer device. Each timbering unit is equipped with an electronic control device which is connected to a computer in a control room. The control units are connected in series via control lines in such a manner that the control data delivered by the computer and the acknowledgment data delivered by the respective addressed control unit are passed on via first receivers and transmitters and via second transmitters and receivers, respectively, from one control unit to the immediately adjacent one in ascending or descending sequence back to the computer. | 4 |
BACKGROUND OF THE INVENTION
1) Field of the Invention
The present invention relates to a push cart transferable to a back holder or a chair, more particularly to a foldable device to be optionally assembled into a push cart, a back holder or a chair after a series of expansion and combination.
2) Description of the Prior Art
Accordingly, the structure of a prior art push cart can only function as a push cart, a back holder or a chair. In other words, a single chair can't be alternatively used as a back holder or a push cart.
Therefore, how to transfer a push cart into a back holder or a chair through a simple expansion and assembly is the research issue of the present invention.
SUMMARY OF THE INVENTION
The primary objective of the present invention is to provide a push cart transferable to a back holder and a chair for achieving the effect of functioning multiply by transferring one object into a push cart, a back holder or a chair through a simple expansion and assembly.
To enable a further understanding of the effect achieved by the features of the present invention, the brief description of the drawings below is followed by the detailed description of the preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial drawing of a push cart of the present invention.
FIG. 2A is a pictorial and exploded drawing of members of an angle adjusting device of the present invention.
FIG. 2B is a pictorial drawing of the assembly of the angle adjusting device of the present invention.
FIG. 3A is a pictorial drawing of the movement of a rocker arm retaining onto a convex rod on a lateral wall of a brake device.
FIG. 3B is a partial cross-sectional and schematic drawing of the working between the brake device and a turning wheel of the present invention.
FIG. 4 is a pictorial and exploded drawing of a back frame and a bottom frame jointed at a connecting mount of the present invention.
FIG. 5 is a pictorial drawing of the push cart of the present invention loaded with a trunk.
FIG. 6 is a pictorial drawing of the movement of transferring the present invention to a chair.
FIG. 7 is a pictorial drawing of the movement of transferring and positioning the present invention to a chair.
FIG. 8 is a pictorial and of an exemplary embodiment of transferring the present invention to a back holder.
FIG. 9 is a pictorial drawing of the folded present invention.
FIG. 10 is another pictorial drawing of the folded present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a pictorial drawing of a push cart of the present invention. As indicated, the present invention comprises a bottom frame ( 10 ) having two adjoining ends ( 12 ) disposed with transverse through holes ( 121 ) thereon, as shown in FIG. 4 . Two connecting mounts ( 20 ) of a longitudinal through hole ( 21 ), the transverse through hole ( 22 ) and a concave slot ( 23 ) are disposed on the main body thereof; an adjoining end ( 12 ) of the bottom frame ( 10 ) is received inside the concave slot ( 23 ).
A shaft rod ( 30 ) penetrates into the transverse through hole ( 22 ) of the connecting mount ( 20 ) and the transverse through holes ( 121 ) of the adjoining ends ( 12 ) to allow the bottom frame ( 10 ) to rotate by using the shaft rod ( 30 ) as a turning shaft.
Upper retaining convex portions ( 421 , 441 ) and lower retaining convex portions ( 422 , 442 ) are respectively disposed at proper positions on lower segments of two left and right lateral tubes ( 42 , 44 ) of a back frame ( 40 ); the left and right lateral tubes ( 42 , 44 ) located between the upper and the lower retaining convex portions ( 421 , 441 , 422 , 442 ) are movably connected into the longitudinal through holes ( 21 ) of the connecting mounts ( 20 ). A pair of turning wheels ( 50 ) are movably connected at the lower aspects of the left and right lateral tubes ( 42 , 44 ).
Proper positions on lower segments of two left and right lateral tubes ( 62 , 64 ) of an upper frame ( 60 ) are positioned slightly above the upper aspects of the left and right lateral tubes ( 42 , 44 ) of the back frame ( 40 ) respectively through an angle adjusting device ( 70 ).
According to the abovementioned main features, wherein the angle adjusting device ( 70 ), as shown in FIGS. 2A and 2B, comprises a left disk ( 72 ) and a right disk ( 74 ) with surfaces thereof disposed respectively with concavo-convex rim surfaces ( 721 , 741 ); through holes ( 722 , 742 ) are disposed at the circle center of the left and right disks ( 72 , 74 ); outer peripheral rims on the hole walls of the through holes ( 722 , 742 ) are formed as circular concave slots ( 773 , 743 ); two ends of a spring ( 75 ) insert respectively into the circular concave slots ( 773 , 743 ).
A screw rod ( 761 ) penetrates into predetermined through holes ( 444 ) of the left and right lateral tubes ( 42 , 44 ) of the back frame ( 40 ), the central through holes ( 722 , 742 ) of the left and right disks ( 72 , 74 ), the spring ( 75 ) and through holes ( 644 ) on the left and right lateral tubes ( 62 , 64 ) of the upper frame ( 60 ); furthermore, a nut ( 76 ) fixedly screws at the outer end of the screw rod ( 761 ). The optional mesh between the concavo-convex rim surfaces ( 721 , 741 ) on the left and right disks ( 72 , 74 ) adjusts the inclination degree between the upper frame ( 60 ) and the back frame ( 40 ).
According to the abovementioned main features, wherein front and rear rims of a seat cover ( 77 ) respectively connect with the shaft rod ( 30 ) and a front transverse rod ( 11 ) of the bottom frame ( 10 ). A back cover ( 78 ) is sleeved onto the back frame ( 40 ), wherein the backside of the back cover ( 78 ) is disposed with a back strap ( 781 ) and a long strap ( 783 ) having a male button ( 782 ) disposed at the front end thereof. A female button ( 771 ) is disposed on the bottom surface of the seat cover ( 77 ). The buckling of the male and female buttons ( 782 , 771 ) positions the folded upper frame ( 60 ), the back frame ( 40 ) and the seat cover ( 77 ).
According to the abovementioned main features, wherein the position near the front segment at the lower aspect of the bottom frame ( 10 ) is disposed with a pair of foldable and expandable positioning frames ( 13 ). The folded positioning frame ( 13 ) affixes to the bottom surface of the seat cover ( 77 ). The lower aspects on two sides of the bottom frame ( 10 ) are disposed with concave portions ( 15 ) for retaining; the inner sides of the left and right lateral tubes ( 62 , 64 ) of the upper frame ( 60 ) are disposed with convex posts ( 65 , 66 ) to be optionally retained onto the convex portions ( 15 ).
According to the abovementioned main features, wherein a turning shaft ( 52 ), as shown in FIG. 3, is disposed between the pair of turning wheels ( 50 ) to penetrate into a transverse through hole ( 82 ) of a brake device ( 80 ) thereby freely rotating therein. The brake device ( 80 ) is clamped fixedly by a clamp slot ( 83 ) of the main body thereof at the lower end of the left and right tubes ( 42 , 44 ) of the back frame ( 40 ). The outer lateral wall of the brake device ( 80 ) is disposed with a convex rod ( 84 ) which penetrates transversely into the clamp slot ( 83 ) and further fixedly connects with the left and right lateral tubes ( 42 , 44 ) of the back frame ( 40 ), as shown in FIG. 3 .
A rocker arm ( 87 ) has a front end disposed with a concave portion ( 871 ) and a rear end movably connected to a proper position at the lower aspect of the bottom frame ( 10 ) through a shaft portion ( 872 ) to allow the rocker arm ( 87 ) to rotate at a certain angle by using the shaft portion ( 872 ) as a turning shaft thereby making the concave portion ( 871 ) to optionally retain onto the convex rod ( 84 ) at a proper time.
Exemplary Embodiment I:
FIG. 2A shows a pictorial and exploded drawing of the members of the angle adjusting device ( 70 ) connecting with the right lateral tubes ( 44 , 64 ) of the present invention. Through the mesh between two concavo-convex rim surfaces ( 721 , 741 ) and the screwing of the nut ( 76 ), as shown in FIGS. 1 and 2B, the upper frame ( 60 ) is fixed onto the back frame ( 40 ) via the angle adjusting device ( 70 ). When trying to adjust the inclination degree between the upper frame ( 60 ) and the back frame ( 40 ), it's only necessary to slightly rotate the nut ( 76 ) to loosen up such that the tension of the spring ( 75 ) separates the two concavo-convex rim surfaces ( 721 , 741 ). At the meantime, when the left and right lateral tubes ( 62 , 64 ) rotate, the right disk ( 74 ) rotates to a certain degree along with the left and right lateral tubes ( 62 , 64 ). Then the nut ( 76 ) is tightly screwed to make the concavo-convex rim surface ( 741 ) rotate to a certain degree to mesh into the concavo-convex rim surface ( 721 ) of the left disk ( 72 ) so as to enable the upper frame ( 60 ) to position onto the angle adjusting device ( 70 ) at an inclination degree, as shown in an assumed line in FIG. 2 B.
The positioning frame ( 13 ) shown in FIG. 1 expands vertically to the bottom frame ( 10 ) for supporting on the ground surface. Therefore, when the present invention is used as a push cart, it has the effect of making temporary pause. The rocker arm ( 87 ) shown in FIG. 3 rotates downwardly by using the shaft portion ( 872 ) as the shaft center thereby retaining the concave portion ( 871 ) onto the convex rod ( 84 ). The positioning of the rocker arm ( 87 ) enables the bottom frame ( 10 ) to obtain further support in order to increase the strength of force bearing thereof; wherein the penetrating clamp slot ( 83 ) disposed on the brake device ( 80 ) is for receiving and fixing the left and right lateral tubes ( 42 , 44 ); the moving body ( 85 ) disposed on the brake device ( 80 ) is depressed downwardly to displace (as an shown in an assumed line position of the moving body ( 85 ) in FIG. 3B) to effectively brake the tuning wheel ( 50 ) and prevent it from making any movement; wherein the moving body ( 85 ) is movably jointed into the main body of the brake device ( 80 ); the inner wall of the moving body ( 85 ) connects with a transverse rod ( 851 ); the inner wall of the turning wheel ( 50 ) is disposed with a plurality of concave slots ( 53 ). The moving body ( 85 ) is depressed downwardly to rotate by using the shaft portion ( 852 ) as the center so as to retain the transverse rod ( 851 ) into the concave slot ( 53 ) to brake the turning wheel ( 50 ). When the moving body ( 85 ) rotates reversely to ascend, the transverse rod ( 851 ) departs from the concave slot ( 53 ); therefore, the turning wheel ( 50 ) looses the brake effect thereby rotating freely. The two moving bodies ( 85 ) of the brake device ( 80 ) respectively disposed at the lower aspects of the left and right lateral tubes ( 42 , 44 ) connect with an n-shaped rod ( 89 ). When a user directly press down or lift the n-shaped rod ( 89 ), it synchronously drives two moving bodies ( 85 ) to displace up and down thereby synchronously controlling the two turning wheels ( 50 ) to brake or not.
The FIG. 4 shows that the left and right lateral tubes ( 42 , 44 ) slide into the longitudinal through holes ( 21 ) of the connecting mounts ( 20 ) such that the connecting mounts ( 20 ) are forced to slide on the lateral tubes ( 42 , 44 ) between the upper retaining convex portions ( 421 , 441 ) and the lower retaining convex portions ( 422 , 442 ). The upper and lower retaining convex portions ( 421 , 441 , 422 , 442 ) block the retaining to prevent the connecting mountings ( 20 ) from slide beyond the positions up and down. In addition, the bottom frame ( 10 ) rotates by using the shaft rod ( 30 ) as the center. FIG. 5 shows that a trunk ( 90 ) is tied onto the bottom frame ( 10 ) and the positioning frame ( 13 ) supports on the ground surface.
Exemplary Embodiment II of a Chair:
FIG. 6 shows the procedure of transferring the present invention to a chair. First, the nut ( 76 ) is loosened. The tension function of two springs ( 75 ) disconnects the two concavo-convex rim surfaces ( 721 , 741 ), as shown in FIG. 2 A. Moving the upper frame ( 60 ) make it sway downwardly by using the screw rod ( 761 ) as the center to further push the upper frame ( 60 ) against the ground surface. Then the nut ( 76 ) is tightened to fixedly screw the left and right lateral tubes ( 62 , 64 ) to position on the right disk ( 74 ); two adjoining ends ( 12 ) of the bottom frame ( 10 ) use the shaft rod ( 30 ) as the turning shaft to rotate from an upright direction to a horizontal direction inside the concave slot ( 23 ). Therefore, the bottom frame ( 10 ) sways from an upright direction to a horizontal direction. Furthermore, the concave portions ( 15 ) retain into the concave posts ( 65 , 66 ) such that the bottom frame ( 10 ) obtains a supportive positioning at a horizontal position; in addition, the connecting mounts ( 20 ) push against and retain at the upper retaining convex portions ( 421 , 441 ) thereby making the bottom frame ( 10 ) have another supporting and positioning function. Then the moving body ( 85 ) is pressed downwardly to brake or stop the turning wheel ( 50 ). As shown in FIG. 7, at the meantime, the seat cover ( 77 ) is provided for a person's body to sit on and the back cover ( 78 ) is provided for the person's back to lean against. The positioning frame ( 13 ) is folded reversely into a slightly horizontal state.
Exemplary Embodiment III of a Back Holder:
In the embodiment of the chair structure shown in FIG. 7, the nut ( 76 ) is loosened to move the upper frame ( 60 ) to rotate reversely at a certain degree to form a back holder as indicated in FIG. 8 . After the back holder is formed, the nut ( 76 ) is screwed tightly again. At this time, the upper frame ( 60 ) is in a folded state and a fixed object ( 92 ) is tied on the horizontal seat cover ( 77 ). The back strap ( 781 ) is inserted by a person's body for back carrying the entire frame. At the meantime, the positioning frame ( 13 ) is folded adjacent to the lower surface of the seat cover ( 77 ).
Exemplary Embodiment IV of the Present Invention in a Folded Status Not For Application:
As indicated in FIGS. 9 and 10, the bottom frame ( 10 ) is folded at an upright direction to lean tightly to the back frame ( 40 ); the upper frame ( 60 ) is folded to make the left and right lateral tubes ( 62 , 64 ) of the upper frame tightly lean against the lateral sides of the bottom frame ( 10 ) and the back frame ( 40 ); the positioning frame ( 13 ) is folded to tightly affix to the bottom surface of the seat cover ( 77 ). At this time, the male button ( 782 ) at the end portion of the long strap ( 783 ) buckles the female button ( 771 ) pre-disposed on the lower surface of the seat cover ( 77 ). Therefore, the bottom frame ( 10 ) and the back frame ( 40 ) won't sway freely. The nut ( 76 ) is screwed tightly to prevent the upper frame ( 60 ) from swaying freely. At the meantime, the long strap ( 783 ) is provided for a person's hand to grip for carrying the present invention.
It is of course to be understood that the embodiment described herein is merely illustrative of the principles of the invention and that a wide variety of modifications thereto may be effected by persons skilled in the art without departing from the spirit and scope of the invention as set forth in the following claims. | A push cart transferable to a back holder and a chair includes a pair of connecting mounts jointing a bottom frame and a back frame as well an angle adjusting device jointing with an upper frame and the back frame; wherein the angle adjusting device adjusts the rotation angle of the upper frame; the bottom frame displaces and positions vertically or horizontally in a concave slot of the connecting mount; the connecting mounts slide at a limited distance on a left and a right lateral tubes of the back frame so as to fulfill the embodiment of being a push cart, a back holder or a chair. | 1 |
BACKGROUND
This invention relates to a connection for supporting a wood post above the top surface of a concrete foundation and for securing the post to an embedded anchor bolt in the concrete foundation to provide resistance to upward movement of the post relative to the concrete foundation. Forces which could cause upward movement of the wood post include earthquakes, hurricanes, typhoons, high winds and tidal or wave forces. This invention further relates specifically to connections which are installed after the concrete foundation has hardened.
There are several types of sheet metal connectors commercially available for providing the connection described above. None, however, have been found which provide the necessary resistance to uplift and are formed from a single piece of sheet metal.
SUMMARY OF THE INVENTION
The gist of the present connection is that it consists of a single part bent from a single piece of sheet metal yet is capable of providing greater gravity load support while also providing greater resistance to uplift forces.
The present connection as a result of the one piece construction is less expensive to manufacture, less expensive to store in inventory, has no problem of missing parts at the retail distribution level, and is less expensive to install by virtue of the fact that the installer is never looking for a missing part.
An additional advantage of the present invention is the fact that the connection may be inspected even after the installation has been completed to determine whether the nut and washer have been properly installed on the threaded end of the anchor bolt.
Another advantage of the present foundation connector is the fact that the wood post does not rest on a solid plate; instead air can circulate beneath the wood post to prevent dry rot,
BRIEF DESCRIPTION OF THE DRAWINGS
FIG, 1 is a perspective view of the post to foundation connector of the present invention.
FIG. 2 is a front elevation view of the post to foundation connector illustrated in FIG. 1
FIG. 3 is a side elevation view of the post to foundation connector illustrated in FIG. 2 and taken along line 3--3.
FIG. 4 is a top elevation view of the post to foundation connector illustrated in FIG. 3 and taken along line 4--4.
FIG. 5 is a cross sectional view of the post to foundation connector illustrated in FIG. 3 taken along line 5--5.
FIG. 6 is a cross sectional view of the post to foundation connector illustrated in FIG. 4 taken along line 6--6. FIG. 6 also illustrates the post to foundation connection of the present invention illustrating a cross sectional portion of the foundation, a portion of the anchor bolt and washer and a portion of the wood post.
FIG. 7 is a sheet metal blank of the present invention set forth in FIG. 1.
DESCRIPTION OF THE INVENTION
This invention is a post to foundation connection 1 including: a concrete foundation 2 having an upper support surface 3; a wood member 4 mounted in an upright position having first and second sides 5 and 6 and a base 7; a foundation connector 8 having: a base member 9 disposed in registration with the upper support surface 3 of the concrete foundation 2 having first and second side edges 10 and 11 and formed with a bolt opening 12, first and second inner leg members 13 and 14 joined respectively to the first and second sides edges 10 and 11 of the base member 9 and positioned in a generally upright manner providing first and second inner foot edges 15 and 16 in registration with the upper support surface 3 of the concrete foundation 2, first and second post support seat members 17 and 18 joined respectively to the first and second inner leg members 13 and 14 and disposed in registration with the base 7 of the wood member 4, and having first and second end edges 19, 20, 21, and 22, first and second outer leg members 23 and 24 joined respectively to the first and second post support seat members 17 and 18 and having first and second outer foot edges 25 and 26 in contact with the upper support surface 3 of the concrete foundation 2, first and second post connection members 27 and 28 respectively joined to the first and second end edges 19 and 20 of the first post support seat member 17 and disposed upwardly in registration respectively with the first and second sides 5 and 6 of the wood member 4, third and fourth post connection members 29 and 30 respectively joined to the first and second end edges 21 and 22 of the second post support seat member 18 and disposed upwardly in registration respectively with with the first and second sides 5 and 6 of the wood member 4, an anchor bolt 31 embedded in the concrete foundation 2 and having a threaded end 32 inserted through the bolt opening 12 in the base member 9; a threaded nut 33 dimensioned for threadable attachment to the threaded end 32 of the anchor bolt 31 for clamping registration with the base member 9; and fastener means 34 joining the first and second post connection members 27 and 28 and the third and fourth post connection members 29 and 30 to the wood member 4.
The post to foundation connection 1 as previously described may also include: the first outer leg member 23 has first and second end edges 35 and 36; first and second outer leg return members 37 and 38 joined respectively to the first and second end edges 35 and 36 of the first outer leg member 23 at an angle of at least approximately 90°; the first outer leg return member 37 is formed with an upper edge 39 positioned below and in close proximity to the first post support seat member 17 and adjacent the first end edge 19 of the first post support seat member 17, and a lower edge 40 in registration with the upper support surface 3 of the concrete foundation 2; the second outer leg return member 38 is formed with an upper edge 41 positioned below and in close proximity to the first post support seat member 17 and adjacent the second edge 20 of the first support seat member 17, and a lower edge 42 in registration with the upper support surface 3 of the concrete foundation 2; the second outer leg member 24 has first and second end edges 43 and 44; third and fourth outer leg return members 45 and 46 joined respectively to the first and second end edges 43 and 44 of the second outer leg member 24 at an angle of at least approximately 90°; the third outer leg return member 45 is formed with an upper edge 47 positioned below and in close proximity to the second post support seat member 18 and adjacent the first end edge 21 of the second post support seat member 18, and a lower edge 48 in registration with the upper support surface 3 of the concrete foundation 2; and the fourth outer leg return member 46 is formed with an upper edge 49 positioned below and in close proximity to the second post support seat member 18 and adjacent the second end edge 22 of the second post support seat member 18, and a lower edge 50 in registration with the upper support surface 3 of the concrete foundation 2.
Preferably the post to foundation connection 1 as previously described is constructed so that the first and third post connection members 27 and 29 are dimensioned so that they overlap, and the second and fourth post connection members 28 and 30 are dimensioned so that they also overlap. The forgoing may be accomplished by forming first post connection member 27 with an extension 51, second post connection member 28 is formed with an extension 52, third post connection member 29 is formed with an extension 53, and fourth post connection member 30 is formed with an extension 54.
In order for first post connection member 27 and third post connection member 29 to present a coplanar surface to second side 6 of wood member 4 an off set is formed between third post connection member 29 and extension 53 as illustrated in FIG. 1 by bending along bend lines 55 and 56. In like manner in order for fourth post connection member 30 and second post connection member and extension 52 to present a coplariat surface to first side 5 of wood member 4 an off set is formed between fourth post connection member 30 and extension 54 as illustrated in FIG. 1 by bending along bend lines 57 and 58.
A feature of the post to foundation connection 1 as described is that the identical blank 63 may be used to construct a foundation connector 8 which can be used with standard size posts or rough sawn posts which are larger dimensionally. This is achieved by providing a first end edge extension 59 joined to and coplariat with the first post support seat member 17 and extending the first end edge 19 outwardly for receiving a larger cross sectional dimension wood member. This is accomplished simply by bending first post connection member 27 upwardly along bend line 64 instead of the bend line which corresponds to first end edge 19. In like manner, a second end edge extension 60 is joined to and coplanar with the first post support seat member 17. This is achieved by a procedure in which second post connection member 28 is bent upwardly along bend line 65 instead of the bend line which corresponds to second end edge 20. Further, third post connection member 29 is bent upwardly along the bend line 66 instead of the bend line which corresponds to first end edge 21 providing a third end edge extension 61 joined to and coplanar with the second post support seat member 18 and extending first end edge 21 outwardly for receiving wood member 4.
Finally, fourth post connection member 30 is bent upwardly along bend line 67 instead of the bend line which corresponds to second end edge 22 providing fourth end edge extension 62 joined to and coplanar with the second post support seat member 18 and extending the second end edge 22 outwardly for receiving the larger wood member 4.
Further strengthening of the supporting capacity of the foundation connector 8 may be achieved by forming first and second outer leg return members 37 and 38 with extensions 68 and 69 which are joined thereto at acute angles by bending along bend lines 70 and 71 as illustrated in FIG. 7. In like manner third and fourth outer leg return members 45 and 46 are formed with extensions 72 and 73 joined thereto at acute angles along bend lines 74 and 75. Extensions 68, 69, 72, and 73, respectively provide upper edges 83, 84, 85, and 86, and lower edges 87, 88, 89, and 90.
Lateral adjustment of the foundation connector 8 relative to anchor bolt 31 is achieved by forming bolt opening 12 in base member 9 as an obround opening. Thus the foundation connector 8 may be shifted laterally as indicated by double headed arrow 91 before tightening nut 33 on threaded portion 32 of anchor bolt 31, and by rotating the foundation connector 8 360°, the foundation connector 8 may be shifted laterally in a lateral direction over an infinite space within the bounds of the length of the obround opening 12. A standard round washer 76 dimensioned to receive anchor bolt 31 therethrough and to prevent movement of threaded nut 33 through obround opening 12 and is positioned between threaded nut 33 and base member 9.
Automatic nailing guns are capable of piercing the metal and attaching the foundation connector 8 to the wood member 4, but preferably first, second, third, and fourth post connection members 27, 28, 29, and 30, and extensions 53, and 54 are formed with fastener openings 77 for receiving fasteners 34 therethrough. Preferably, openings 78 are enlarged in extensions 51 and 52 to allow for some misalignment between extensions 51 and 52 and overlapped extensions 53 and 54.
The foundation connector 8 may be constructed from a single 16 gauge galvanized piece of sheet metal approximately 71/4×7 3/4". The foundation connector 8 may be formed on an automatic machine and the folding may proceed in an order determined by the tooling. The following description of folding is not necessarily the order used.
First and second inner leg members 13 and 14 are created by bending up 90° along bend lines which are coincident with first and second side edges 10 and 11. First and second support seat members 17 and 18 are formed by bending down 90° along bend lines 79 and 80, and down 90° along bend lines 81 and 82.
To accommodate dimensional lumber, first post connection member 27 is bent up 90° along a bend line which is coincident with first end edge 19, second post connection member 28 is bent up 90° along a bend line which is coincident with second end edge 20, third post connection member 29 is bent up 90° along a bend line which is coincident with second end edge 22, and fourth post connection member 30 is bent up 90° along a bend line which is coincident with second end edge 22.
To accommodate rough sawn lumber which is dimensionally larger than dimensional lumber, the foregoing first, second, third and fourth post connection members 27, 28, 29, and 30 are bent up 90° along bend lines 64-67.
To give extra columnar strength and to shield the base from intrusion of foreign objects beneath the foundation connector 8, first outer leg return member 37 should be bent down 90° along a bend line which is coincident with first end edge 35, and extension 68 may be bent down 90° along bend line 70; second outer leg return member 38 should be bent down 90° along a bend line which is coincident with second end edge 36, and extension 69 may be bent down 90° along bend line 71; third outer leg return member 45 should be bent down 90° along a bend line which is coincident with first end edge 43, and extension 72 may be bent down 90° along bend line 74; and fourth outer leg return member 46 should be bent down 90° along a bend line which is coincident with second end edge 44, and extension 73 may be bent down 90° along bend line 75. | A post to foundation connection for joining a wood post to an anchor bolt embedded in a concrete foundation after the concrete has hardened. The post to foundation connection includes a foundation connector which is formed from a single sheet metal blank which provides post support on a pair of post support seat members raised above the top surface of the foundation and supported by at least four leg members. Uplift resistance is provided by attaching the foundation connector to the embedded anchor bolt by a nut and washer which bears against a base member formed in the foundation connector. Attachment to the post is provided by four post connection members integrally attached to the ends of the post support seat members. | 4 |
This is a continuation-in-part of application Ser. No. 08/733,654, filed Oct. 17, 1996, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the cutting of hardwood flooring, specifically a jig used in combination with a miter saw to cut precise lengths to fit between two headers.
2. Description of the Prior Art
The laying of hardwood floors is a labor intensive manual process. In the past, borders and other interesting features were often included in a hardwood floor design. These designs often involved laying flooring between two fixed headers. Both ends of the flooring pieces are exposed and the pieces must be cut for a tight fit. Many newer hardwood floors have a fit between the headers and the flooring that is uneven and irregular because installers can no longer afford to take the time necessary to achieve a good fit. Flooring is now often laid from wall to wall, with baseboards eventually covering the unevenly cut ends of the flooring. Today's housing market, with its high demand for unique details and for hardwood floors creates a need for a less tedious method to precisely cut flooring to fit between two headers.
The usual process for fitting flooring between two headers begins with the headers fastened in place. The installer begins by butting one end of a piece of flooring against one of the headers and against the previously laid course. The piece is then nailed in place. The installer continues laying flooring in that course, butting each piece against the end of the previous piece, working toward the opposite header. The last piece of flooring in the course must then be accurately cut to length.
Cutting the last piece in a course requires many steps. The installer lays the piece of flooring in place, one end butted against the previous piece and the other end laying on top of the second header. Then, very carefully, the place where the piece should be cut is marked with a pencil. The board is then cut off, often using a miter saw, and tried in place to see how it fits. Due to lack of precision in this method, boards often are cut more than once, in a trial and error process to achieve a precise fit. If a board is cut too short, there is a gap between the board and the header. If a board is left too long and forced into place, it tends to force the headers apart and create a gap at the end of the boards previously laid.
Shortcomings of this process include the following. The flooring strip to be cut lays at an angle to horizontal, making a precise mark difficult. The pencil mark width may change over time as the pencil lead is worn down. The mark is visually aligned with the saw blade to make the cut. The piece is then tried in place and often must be recut. This trial and error method takes a lot of time, as pieces are visually aligned, cut, tried and recut. Small imprecisions result in an imperfect fit. This process is a very labor intensive and therefor costly.
There are a variety of saw guides available that facilitate accurate cutting of building material at a predetermined place. This jig is used to determine the place of the cut to allow for a precise fit, in addition to facilitating an accurate cut.
OBJECTS AND ADVANTAGES
Accordingly, several objects and advantages of the jig for cutting hardwood flooring to exact lengths are:
(a) to provide jig that eliminates the inconsistent fit produced by the prior art;
(b) to provide a jig that eliminates the time-consuming trial and error method, and therefor save time and money;
(c) to provide a jig that eliminates the need for aligning visually the location on the flooring strip where the cut is to be made;
(d) to provide a jig that eliminates the need for marking the flooring with a pencil, which may result in imprecision in the dimension or placement of the mark;
(e) to provide a jig that eliminates the need for visually aligning the location at which the saw blade will cut the flooring strip;
(f) to provide a jig that allows the user to make precise cuts while keeping face and hands at safer distances form the saw blade than may be the case with the prior art;
(g) to provide a jig that allows a precise fit to be made with ease, even by less experienced installers;
Further objects and advantages of my invention will become apparent from a consideration of the drawings and ensuing description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a jig, in accordance with one embodiment of this invention.
FIG. 2 is an exploded view of a jig.
FIG. 3 is a perspective view of a jig base with a flooring strip in place.
FIG. 4 is an end view of a jig with a flooring strip in place.
FIG. 5 is a perspective view of a jig with a flooring strip in place, in use between a previously laid strip and a header.
FIG. 6 is a top view of a jig with a flooring strip in place, in use between a previously laid strip and a header.
FIG. 7 is a rear view of a jig with a flooring strip in place, in use between a previous laid strip and a header.
FIG. 8 is a perspective view of a miter saw base and blade, with stop attached.
FIG. 9 is a perspective view of a jig in place against a stop on a miter saw base.
FIG. 10 is a perspective view of a jig holding a flooring strip in cutting position on a miter saw base.
FIG. 11 is a rear view of a jig holding a flooring strip in cutting position on a miter saw base.
FIG. 12 is a side elevational view of a preferred embodiment of the present invention illustrating how a workpiece is secured within the jig body.
FIG. 13 is a perspective view of the jig body arranged upon the base of a saw, also showing the stop member of the present invention secured to the base of the saw.
REFERENCE NUMERALS IN DRAWINGS
10 Jig
12 Jig Base
14 Jig Top
16 Jig Pin
18 Jig Screw
19 Jig Screw Washer
20 Locating Strip
22 Locating Pin
24 Locating Strip Screws
26 Flooring Strip Being Fit/Cut
28 Header
30 Previous Flooring Strip
32 Area of Flooring already Laid
34 Miter Saw Base
36 Miter Saw Blade
38 Jig Stop
40 Jig Stop Pin
42 Jig Stop Screw
44 Jig Stop Registration Means
46 Jig Body Registration Means
SUMMARY
This jig allows a miter saw to cut each piece of hardwood flooring to a precise length in one cut. A flooring strip, inserted into the clamp body, is butted against the previous strip. The locating strip, attached to the clamp body, butts against the [opposing] header. The clamp top is tightened to hold the flooring strip in place, within the jig. The jig, with the flooring strip clamped inside of it, is placed on the miter saw base and butted against a provided stop. The saw will then cut the flooring strip in the desired location.
DETAILED DESCRIPTION OF THE INVENTION
A typical embodiment of the jig is illustrated in perspective in FIG. 1 and in an exploded view in FIG. 2. A jig consists of a jig base 12 and a jig top 14. A jig pin 16 aligns the jig top with the jig base. A jig screw 18 with washer 19 secures the jig top to the jig base. Locating pins 22 protrude from the jig base. A locating strip 20, made of a wear-resistant, easily cut material such as sheet acrylic, is attached to the jib base with screws 24.
FIG. 3 is a perspective view showing jig base 12 with a flooring strip 26 in place on locating strip 20 and against locating pins 22. FIG. 4 shows an end view of the flooring strip on the jig base with jig top 14 secured in place by jig screw 18.
FIG. 5, FIG. 6 and FIG. 7 are perspective, top and rear views of jig 10 in use to fit flooring strip 26. The flooring strip is next to an area of flooring already laid 32, with one end abutting a previous flooring strip 30. The other end of the flooring strip is resting on a header 28. Locating strip 20 under the flooring strip is against the header.
FIG. 8 shows a generic miter saw base 34 and a miter saw blade 36. A jig stop 38 is attached to the miter saw base with a pair of jig stop screws 42. Two jig stop pins 40 protrude from the jig stop. FIG. 9 shows jig 10 in place on the miter saw base, against the jig stop and the jib pin nearest the saw blade.
FIG. 10 and FIG. 11 show a perspective view and a rear view of jig 10 with flooring strip 26 secured in place. The jig is on miter saw base 34, against jig stop 38 and jig pin 40 nearer saw blade 36. The end of locating strip 20 is aligned with the edge of miter saw blade 36.
FIG. 12 shows a side elevational view of the preferred embodiment of the jig body 10 having a workpiece 26 secured therein by means of a jig screw 18.
FIG. 13 illustrates how the jig body 10 is received upon the saw base 34 in registration with the saw blade 36 as dictated by the position of the jig stop registration means 44 formed in the jig stop member 38. FIG. 13 also shows how the preferred embodiment of the ht jig stop or stop member 38 is typically secured to a saw base 34.
OPERATION OF THE INVENTION
Operation--FIGS. 8, 9
A jig stop 38 is attached to miter saw base 34 in a position such that when a jig 10 is placed against the jig stop and a jig stop pin 40 nearest to a miter saw blade 36, a locating strip 20 extends slightly beyond the cutting plane. The miter saw blade is then brought down to cut off the locating strip, calibrating the jig with the miter saw blade. (The locating strip, made of sheet acrylic in this embodiment, is a replaceable part.)
Operation--FIGS. 4 to 7
The method by which jig 10 is used will now be described. A tongue and groove flooring strip 26 is laid finished side down, with its groove end tight against the end and resting on the tongue of a previous board 30 and its tongue end resting on a header 28. The jig is placed so that the flooring strip rest son locating strip 20 and against the two locating pins 22. The jig is then pushed along the flooring strip so that the locating strip is firmly against the header, above its tongue. A jig screw 18 is tightened to hold a jig top 14 firmly against the flooring strip.
Operation--FIGS. 10, 11
As described above, jig stop 38 has previously been attached to miter saw base 34 and calibrated. Jig 10 holding flooring strip 26 is placed on the miter saw base and pushed firmly against the jig stop and jig stop pin 40 nearest to miter saw blade 36. The miter saw blade is then brought down, cutting the flooring strip precisely at the end of locating strip 20. The flooring strip is then removed from the jig. (A groove must then be cut into the cut end of the flooring strip so that it can be inserted between previous board 30 and header 28.)
An improved and preferred embodiment of the workpiece cutting jig of the present invention is illustrated in FIGS. 12 and 13. The jig body or clamping body 10 of the preferred embodiment is a solid extruded channel. The space or channel between the top 14 and the base 12 of the clamping body is sized to receive variously sized workpieces 26. The extrusion is preferably of an aluminum material, however, steel, plastics or other suitable composite materials may be utilized. Use of an extruded channel simplifies the assembly of the jig body 10.
The locating pins 22 of the above-described alternate embodiment of the present invention are, in this preferred embodiment, replaced with a continuous locating ridge 22. A workpiece 26 is inserted between the base 12 and top 14 of the jig body 10 and is aligned therebetween by the locating ridge 22 which abuts the workpiece 26 along the entire length of the jig body 10. The workpiece 26 is secured within the jig body 10 by use of a workpiece retention means 18, which may be a jig screw as described above. Alternatively, the workpiece retention means 18 may comprise an eccentric clamp or other spring clamp device. A locating strip 20 is secured to the base 12 of the jig body 10 and is used to align a workpiece 26 within the jig body 1 in order to cut a workpiece to a desired length as described above.
The means for registering the jig body 10, and hence the workpiece, with the saw blade 36 have been modified to allow the saw to be utilized for cutting operations unrelated to the installation of flooring. Using the jig stop member 38 illustrated in FIG. 13, a saw that is being used to cut workpieces 26 may also be used to cut other items without first needing to remove the stop member 38 from the saw base 34. As illustrated in FIG. 13, the jig stop member 38 may comprise an auxiliary fence that is secured to the saw base 34 by screws or other fasteners 42.
In this preferred embodiment, the jig body 10 has been provided with jig body registration means 46 which may comprise one or more pins that protrude or project from the rear surface of the jig body 10 (FIG. 13). These jig body registration means 46 are arranged and constructed to mate with the jig stop registration means 44 formed in the jig stop member 38 so as to repeatably and reliably register the jig body 10 with the saw blade 36 in a predetermined manner as described above. The jig stop registration means 4 may comprise one or more apertures or detents formed into the jig stop 38 so as to receive the jig body registration means 46. In some instances, where the saw base 34 itself is provided with apertures, holes, or detents of a type suitable for receiving jig body registration means 46 such as the above described pins, the stop member 38 may be omitted as the saw base 34 itself may act as the stop member 38.
It is to be understood that the jig stop registration means 4 which may variously comprise holes, apertures, detents and the like, and the jig body registration means 46, which may variously comprise pins, protrusions, or similar structures, are interchangeable. Subsequently, pins or protrusions may be formed on the jig stop member 38 and mating holes, apertures, or detents may be formed in the jig body 10 and vice versa. The only structural requirement is that the jig body 10 be repeatably and reliably registratable with the saw blade 36 of a saw so as to be able to cut a workpiece 26 in an accurate and repeatable manner.
It is also to be understood that the present invention may be adapted for use with a number of different types of saws and cutting devices without exceeding the scope of the appended claims. The various embodiments of the present invention may be modified for use with commonly available miter saws (powered and hand operated), radial arm saws, and chop saws. The present invention may also be modified for use with a table saw. Where the workpiece cutting apparatus is to be used with a standard table saw, the jig body registration member 46 would be arranged and constructed to take advantage of the miter gage slots formed into the table saw top 34 so as to register the jig body 10 with the table saw blade 36.
CONCLUSION, RAMIFICATIONS AND SCOPE
Accordingly, the reader will see that the jig of this invention can be used to cut hardwood flooring to fit between two headers easily and conveniently. The ease of use of the invention allows a professional floor installer or a do-it-yourselfer to accurately lay an interesting floor. This highly reliable tool will allow borders and other interesting patterns to be laid in significantly less time than previous methods, reducing the expense and tedium of trial and error methods as well as improving the precision of the fit. Furthermore, the invention has the additional advantages in that
it allows the installer to precisely measure the board without having to mark it with a pencil, therefore saving time and eliminating any variation in the dimension or placement of the mark;
it allows the installer to precisely cut the board while keeping face and hands at safer distances from the saw blade than may be the case if visually aligning a pencil mark on a board;
it eliminates the time-consuming trial and error method, and the inconsistency that can result from repeated cutting of flooring strips using manual marking and cutting methods;
While the description above contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Many other variations are possible. For example, the type of saw or cutting device may vary, and thus the type of jig stop may vary to fit the saw. The jig top may be aligned with the jig base using a method other than an alignment pin. The locating strip may be replaced by another locating element such as a pin, serving the same function. The jig may be applied to precisely cutting other building materials in appropriate applications. | A jig which allows hardwood flooring or other building material to be cut to an exact length to fit with precision between two fixed pieces of building material. The jig includes a marking member which attaches to a workpiece which is positioned with one end abutted to a fixed piece of building material and the other end extending beyond a second fixed piece of building material. The marking member attaches to the workpiece in such a way that it is secured in a precise position relative to the second fixed piece of building material. The jig also includes a receiving member which is affixed to a cutting device. The marking member, when aligned with the receiving member, serves as a saw guide that allows consistent cuts to be made so that the workpiece will fit with precision between the two fixed pieces of building material. | 4 |
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention relates to luggage equipped with a compact player/recorder; the luggage owner records an identifying message which can be played back by a luggage handler for the purpose of locating the luggage owner. Written instructions on the luggage tell the handler to push a button on the luggage to play the message.
2. DESCRIPTION OF THE PRIOR ART
Ever since the beginning of commercial transportation, business and leisure travelers alike are plagued with the fear that their luggage and other belongings will be lost or misshipped. Such belongings are entrusted to the care of sky caps, baggage handlers, bellmen and others who may fail to deliver the luggage and belongings in a timely fashion, or worse yet, direct the luggage and belongings to the wrong destination. While identifying baggage tags and other indicia help, often this data is out of date and/or only gives the owner's home address and telephone number. Such data is unlikely to assist in guiding the handler as to where to deliver the luggage and belongings during the owner's travels, viz., to a hotel or inn where the traveler will be staying. Clearly, then, the need exists for a more reliable means and method for better assuring the accurate and timely delivery of luggage and belongings to a traveler during his travels.
The instant invention provides the answer in the form of a small player/recorder whereby the user may record a message and then update the message periodically during his travels. Only the owner has access to the recorder/player to record and update his or her message. A baggage handler may simply push a single button on the outside of the luggage piece within which the invention is installed to listen to the prerecorded message of the owner. The message may, for example, give the owner's name, date and where the traveler is or may be staying. Simple printed instructions on the exterior surface of the piece of luggage instantly inform the handler what to do, e.g., push a button, and what this will tell him, e.g., owner and location of the owner of the piece of luggage.
Thus, the present invention, by providing a voice message to luggage handlers and others, will make it quite likely that the luggage is sure to be directed to its owner in a timely and accurate manner.
The prior art includes several examples of message recorders and players that deliver an audible message upon the occurrence of an event or events, but these are oblique to both the construction and function of the instant invention.
U.S. Pat. No. 4,117,461, issued on Sept. 26, 1978, to Carol L. Kiebala, discloses a tape recorder that plays a message encouraging dieting, when a door of a food storage compartment is opened and food or a food container is removed from a shelf. The instant invention is distinguishable, no only as to the environment of use, but also in that the message player is activated by pushing a button rather than opening a door, the message can be changed by the owner, and the message gives the name and current location of the owner.
U.S. Pat. No. 4,117,468, issued on Sept. 26, 1978, to Talio Vasquez, discloses a device that sounds an alarm to prevent a briefcase from being stolen. The instant invention is readily distinguishable in that it gives a verbal message, and can be activated by a legitimate luggage handler by simply pushing a button and then directing the luggage according to the message heard.
U.S. Pat. No. 4,400,787, issued on Aug. 23, 1983, to Alan F. Mandel and Kenneth M. Eichler, discloses an elevator system with a speech synthesizer for repetition of messages. The instant invention is distinguishable in that, besides being designed for luggage rather than elevators, the message is played in direct response to the listener pushing a button for that purpose.
U.S. Pat. No. 4,728,937, issued on Mar. 1, 1988, to Chi-Hsueh Hsu, discloses a security system for a suitcase, which gives a buzzing sound as a warning and then an electric shock to someone attempting to steal the suitcase. It does not give a verbal message which a legitimate luggage handler may access, and thus is quite unlike the instant invention.
U.S. Pat. No. 4,804,943, issued on Feb. 14, 1989, to Isaac Soleimani, discloses a remotely controlled briefcase alarm, which does not give a verbal message that may be played by a legitimate handler.
U.S. Pat. No. 4,843,371, issued on Jun. 27, 1989, to Liu C. Kuei, Chen C. Shui and Huang C. Lung, discloses a burglar-alarm system for a briefcase, which relies on electric shock, alarming sounds, flashes of light, and colored smokes, to prevent theft, but does not give a verbal message that may be played by a legitimate handler.
U.S. Pat. No. 4,884,507, issued on Dec. 5, 1989, to Isy R. Levy, discloses a security container or case for the storage of documents, credit cards, or other valuable materials, which will destroy such materials when someone attempts to steal the container. It does not play a message so that a legitimate handler may direct the luggage to its rightful owner.
U.S. Pat. No. 5,145,447, issued on Sept. 8, 1992, to Adolph E. Goldfarb, discloses a multiple choice verbal sound toy, which has a variety of keys to be depressed by a user, each of which cause a song or poem to be played. Unlike the instant invention, it does not allow new messages to be recorded by the owner and is not directed to the lost luggage problems of travelers.
U.S. Pat. No. 5,153,561, issued on Oct. 6, 1992, to Eric S. Johnson, discloses a secured valuable box for beach goers, which sounds an audible alarm, but does not play a message recorded by the owner and identifying the owner and just where he or she is staying or may be found.
U.S. Pat. No. 5,241,307, issued on Aug. 31, 1993, to Gerard Bidault and Dominique Leveque, discloses a sound signaling generation device for pedestrians, in which sound and optical signals are both activated by a single push button. It may be distinguished from the instant invention in that it is not designed to play a message recorded by an individual owner, especially in the context of lost luggage identification and retrieval.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
SUMMARY OF THE INVENTION
The present invention provides the answer to lost luggage and its use allays the fear and concern of travelers that their luggage and other belongings will be lost. Also, common carriers and their insurers will save the costs associated with lost luggage claims, as any piece of luggage equipped with the present invention can be instantly identified and forwarded on to its owner wherever he may be during his travels. Furthermore, inefficiencies of operation associated with lost luggage in the travel industry as well as loss of goodwill and trust can be eliminated. The instant invention provides an uncomplicated little player/recorder that instantly transforms a piece of luggage to "talking luggage" that identifies the owner and his or her location by the mere pressing of a button. The player/recorder is installed into a pouch receiver within the luggage so that only the luggage owner has access to it to record and update an identifying, prerecorded message. During travel, should the luggage piece become lost or mishandled, all a handler has to do is press a button, as directed by indicia instructions readily seen on the outside of the piece of luggage, in order to hear an audible message which informs the handler of the owner's name and location at that point in the owner's journey. However, assuming the piece of luggage is locked, the handler does not have access to the inside of the luggage, and thus the identifying and locating message prerecorded by the owner remains intact until changed by the owner.
Accordingly, it is a principal object of the invention to provide a convenient means of identifying luggage by an audible message, prerecorded by the luggage owner.
It is another object of the invention to provide a means of identifying luggage that may be used by simply following printed instructions, pressing a button, and listening to a prerecorded, identifying message.
It is a further object of the invention to provide an audible luggage identifier, to help prevent luggage from being accidently lost or stolen.
Still another object of the invention is to provide a means of audibly identifying luggage, where the information provided can be easily updated.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is elevational front view of the invention installed within a piece of luggage.
FIG. 2 is a top view of the invention as seen in FIG. 1.
FIG. 3 is an enlarged scale, elevational front view of a portion of the invention.
FIG. 4 is an enlarged scale, top view of the printed instructions portion of the invention.
FIG. 5 is an enlarged scale, top view of the pouch container for housing the player/recorder of the invention.
FIG. 6 is an elevational end view of the pouch of the invention as seen in FIG. 5.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Essentially, the invention is made up of a player/recorder having an irregular polyhedronal case configuration, a pouch container permanently installed within a piece of luggage, so that only the luggage owner has access to the player/recorder to record and update an identifying message, and indicia, perceivable from the exterior of the luggage, directing a luggage handler to simply press a button to hear a prerecorded message which identifies the owner of the luggage and his present or soon to be location during his journey.
FIG. 1 shows a piece of luggage in the form of a suitcase 10, having a handle 12, and the invention 14, including a message recorder and player, or player/recorder 14, installed within the luggage 10. FIG. 2 shows the same from the top of the luggage 10. The invention is innocuously sized and located, so as not to interfere with the regular utility of the luggage 10, yet is easily accessed from inside the luggage, in a manner and for a purpose to be explained hereinbelow, and can be operated from the exterior of the luggage by a luggage handler.
As employed in the context of the instant invention, the term "luggage" is meant to include, without limitation, a broad range of luggage pieces, such as hard sided and soft sided suitcases of any and all sizes, briefcases, ski and ski boot bags, bags, tennis racket cases, musical instrument cases, gun cases, carry-on luggage of any sort and description, overnight bags, sample cases, display cases, golf club bags, lunch bags, and most any other sort of container with or without a handle.
As can be appreciated from an inspection of FIG. 3, the player/recorder 15 of the invention 14 is housed within a pouch container 32, which is permanently installed within the luggage 10 as will be explained below. The player/recorder 15 is battery powered, and includes a pair of replaceable batteries 26, 26, for example. A record button is located at 16 and an activator, message play button is located at 17, beneath an externally accessible activator 18, positioned directly atop the button 17. The player/recorder is of irregular, polyhedronal configuration so that it fits into pouch container 32 in only one disposition, thus to assure that button 17 is always directly beneath activator 18. As can be further appreciated from FIG. 3, the left side 20 of the pouch 32 includes an access door 22, hinged at 24 to be opened, so that the player/recorder 15 may be removed to record a message, and thereafter reinserted into pouch 32 and secured therein. The construction of hinge 24 may be a simple pin hinge, or piano hinge, or a living hinge, particularly when the pouch 32 is cast or molded as an integral unit of suitable plastics material or the like. The door may have a latch construction to keep the door closed, as by provision of a pair of tabs 40, 40 received in friction fit fashion in a pair of slots 42, 42, seen in FIG. 6, formed in a door latch plate 44, formed as an extension of the pouch container 32.
Referring now to FIGS. 3 and 4, the invention includes an exterior mounting and message plate 21 which provides readily perceived, printed instructions for the baggage handler. Once the message is recorded by the user and the recorder 15 installed and latched into pouch 15, the invention is ready for use. Thus, a baggage handler need only depress the activator 18 to hear a message, such as: "I belong to Mr. Jones, staying at the Hyatt Regency Hotel, Chicago O'Hare Airport, Feb. 14 to 18. Please expedite me to that location." Should the baggage handler not remember all the information recorded, he need only press the activator 18 again, since the player/recorder 15 includes a standard reset, wherein once the message is heard, the device automatically rewinds so that the message may be heard again.
It is noted here that the internal electronics of the recorder/player 15 form no part of the instant invention per se. Such devices are readily known and available. As for the instant invention, only the external configuration of the case of the device 15 is novel, so that it fits in pouch 32 in only one manner, thus to assure that the button 17 is beneath the activator 18.
The mounting and message plate 21 is attached permanently to both the luggage 10 and the recorder/player pouch container 32 by any suitable means, such as a number of rivets 33, secured through the plate 21, a wall of the luggage 10, and into and through a mounting flange 35, formed at the top of the pouch 32, as best seen in FIGS. 5 and 6. The plate 21 may be made of a clear plastic material with the instruction message 30 engraved into the bottom or underside thereof, so that it will not be worn off, even by repeated usage of the luggage. Alternatively, the plate may be translucent, or opaque; in the latter instance, of course, the instruction message 30 would be engraved into or printed upon the top surface of the plate 21.
As will be appreciated from FIGS. 2, 3 and 4, message sound from the player/recorder minispeaker 19 may be heard externally by providing a plurality of openings 28 through the plate 21. Alternatively, of course, the speaker 19 could be located immediately beneath the openings 28 (not shown).
By now, it will be fully realized that the baggage handler need only follow instructions and depress button activator 18 in order to hear a prerecorded message as to where to direct the piece of luggage at hand. It will be noted here that, assuming the piece of luggage 10 is closed/locked, the handler will have no access to the player/recorder 15, where he or she could inadvertently or deliberately change or erase the message prerecorded by the luggage owner. Also, the traveller, after completion of a leg of his or her trip, may simply open door 22, remove the player/recorder 15 and record a new message, and then reinstall the player/recorder.
It is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims. | Luggage, having an audio recording and playing device within the luggage, housed in a pouch. The device is removable by the owner so that a message indicating where the owner is in his travels can be recorded on the recorder/player. An external plate includes indicia directing a luggage handler how to play the identifying message. | 0 |
BACKGROUND OF THE INVENTION
In a conventional labeling operation, articles to be labeled are conveyed single file through a labeling station. A label applicator at the labeling station applies a label to each article as such passes through the labeling station.
There are instances in which it is desirable to label articles which are arranged in side-by-side relationship on a conveyor. For example, some packaging equipment provides an output which includes side-by-side packages. There are also instances in which multiple rows of containers in open top cartons must be labeled.
One way to label side-by-side articles is to employ a wide backing strip carrying side-by-side labels and a wide peeling bar to remove the side-by-side labels from the backing strip. Label applicators of this type are known. However, the wide backing strip wastes a large amount of paper especially when the labels are relatively small and the articles to be lableled are relatively large and/or widely spaced. Thus, this approach becomes more impractical as the overall combined width of the side-by-side articles to be labeled increases. In addition, this method of label application cannot utilize the standard single row of labels on a backing strip.
SUMMARY OF THE INVENTION
The present invention provides a label applicator which is particularly adapted for labeling articles arranged in side-by-side relationship. The label applicator of this invention uses labels arranged in a conventional manner in a single row on the backing strip and so no paper is wasted.
The environment in which the present invention is particularly adapted to operate includes a conveyor or other means for conveying articles to be labeled along parallel paths to a labeling station. The articles to be labeled do not pass single file through the labeling station, but rather pass through the labeling station in side-by-side relationship forming sets or columns.
In order to label the column of articles, the present invention provides for moving a plurality of labels arranged in a row along a label path at a labeling station. The axes of the row and the label path are generally parallel to each other and to the column. Thus, the labels and the articles can be brought into registry, and the labels can be transferred to the articles of the column.
Typically, the articles are moved in a first direction through the labeling station in multiple rows. The axes of the rows of labels and the label path are angularly related to the first direction, i.e. nonparallel to the first direction. In other words, the row of labels extends across the multiple rows of the articles, and preferably the axes of the row of labels and the label path are transverse to the first direction.
The labels can be advantageously transported along the label path by a conveyor belt. The labels are deposited in sequence on the belt at a depositing station and the belt moves the labels along the label path. The labels can be retained on the belt by differential fluid pressure. In order to accomplish this, the conveyor belt preferably includes opening means so that a subatmospheric pressure can be applied to the opening means to retain the labels against the belt. The opening means can also be used to enable air under pressure to be blown through the opening means to transfer the labels from the conveyor belt to the articles to be labeled.
Before a label is applied to an article, it must be properly positioned on the belt so that it is in registry with as associated article. This may be accomplished in whole or in part by snychronizing the movement of the article conveyor with the rate at which labels are deposited on the belt. In a preferred embodiment, such synchronization is employed to roughly position the labels on the belt. Fine positioning is obtained by positioning means which is extendible through the opening means of the belt to engage the labels and retain them in the desired position. Once the labels are engaged by the positioning means they slip on the belt while the belt continues to run. One advantage of vacuum retention means for holding the labels on the belt is that such means allows the labels to slip on the belt to allow the labels to be positioned correctly.
The invention, together with further features and advantages thereof, may best be understood by reference to the following description taken in conjunction with accompanying illustrative drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially schematic side elevational view of a label applicator constructed in accordance with the teachings of this invention suitably mounted in position above a conveyor for articles to be labeled.
FIG. 2 is a fragmentary plan view of the construction shown in FIG. 1.
FIG. 3 is a perspective view with parts broken away of a portion of the label applicator and the article conveyor.
FIG. 4 is a somewhat schematic fragmentary sectional view of a portion of the label applicator with the labels being positioned above the articles to be labeled.
FIG. 5 is a sectional view similar to FIG. 3 after the articles have been labeled and with the positioning pins withdrawn to the unactuated position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a label applicator 11 which generally includes a supporting structure 13 and a label transport 15 mounted on the supporting structure. A web or backing strip 17 carrying adhesive labels 19 in the usual manner is wound on a supply reel 21 which in turn is rotatably mounted on the supporting structure 13 or on another structure (not shown), if desired. The backing strip 17 extends over a plurality of guide rollers 23 and between drive rollers 25 to a take-up reel 27. The drive rollers 25 include one pinch roller and one power roller. The drive rollers 25 are driven by an electric motor (not shown) through a clutch and brake as is conventional in the label applicating field. A peeling bar 29 is suitably mounted on the supporting structure 13, and the web 17 extends over the peeling bar.
The label transport 15 includes a housing 31 which is adapted to contain air at less than atmospheric pressure which may be provided by a suitable vacuum source such as a vacuum pump 33. The housing 31 is substantially sealed except for the lower end thereof which is gas pervious. As described more fully hereinbelow, a conveyor belt or label transport belt 35 is mounted for movement along the bottom of the housing 31.
Movement of the web 17 across the peeling bar 29 sequentially removes the labels 19 and deposits them at a depositing station on the conveyor belt 35. The labels are releasably retained on the conveyor belt 35 as described more particularly hereinbelow by the vacuum pressure within the housing 31. As the labels 19 are deposited on the conveyor belt 35, they are moved along a label path in the direction of the arrow A in FIG. 2. The labels 19 on the conveyor belt 35 are arranged in a row, the axis of which coincides with the axis of the label path.
As shown in FIGS. 1 and 2, the label path extends above a conveyor 37 for three rows 39, 41 and 43 of articles 45. The conveyor 37, which may be of any construction suitable for moving articles to be labeled through a labeling station, moves the rows 39, 41 and 43 along spaced parallel paths in the direction of the arrow B in FIG. 2. Although three rows of the articles 45 are shown on the conveyor 37, this is purely illustrative, and any desired number of rows of articles may be labeled with the label applicator 11. In the embodiment illustrated, the direction of movement of the articles is transverse to the direction of movement of the labels 19 on the belt 35.
As shown by way of example in FIG. 2, the articles 45 of the rows 39, 41, and 43 are arranged in side-by-side relationship with the articles 45 beneath the conveyor belt 35, i.e. the articles at the labeling station, forming a set or column of articles. The axis of the column of articles 45 is parallel to the axes of the row of labels 19 on the conveyor belt 35 and to the axis of movement of the labels 19 on the conveyor belt.
As the articles 45 come into registry with the labels 19, the labels 19 on the conveyor belt 35 are transferred to the articles 45, respectively. This transferring can be advantageously carried out utilizing air at greater than atmospheric pressure obtained from suitable pressure source (not shown) through a valve, such as a solenoid valve 47. The articles 45 of a column may be labeled sequentially or simultaneously.
FIGS. 3-5 show a preferred construction for the label transport 15. In some respects the label transport 15 is similar to conventional vacuum belt transports. In FIG. 3, the housing 31 has been broken away to expose the interior of the label transport 15.
In the embodiment illustrated, the conveyor belt 35 is an endless belt and comprises a plurality of endless flexible conveyor strips or belts 49. Adjacent strips 49 are spaced apart to define opening means in the form of elongated slots 51. The conveyor belt 35 has an interior belt surface 53 (FIG. 4) and an exterior belt surface 55 (FIG. 4).
The belt 35 is mounted for movement by a plurality (three being illustrated) of idler rollers 57 and a drive roller 59 each of which is suitably rotatably mounted on the housing 31. The drive roller 59 is driven by a suitable motor 60 through a clutch and brake unit 62. In the embodiment illustrated, the rollers 57 and 59 are arranged at four corners of a trapezoid and this allows the belt 35 to surround other important structure of the label transport 15; however, obviously other configurations can be utilized.
A plate 61 is suitably mounted on the remainder of the housing 31 and forms a bottom wall for the housing. The plate 61 has a plurality of apertures 63 extending therethrough with the apertures being in registry with the slots 51. The plate 61 is continuous and unbroken and is shown broken away in FIG. 3 to expose other portions of the transport 15.
Various different arrangements can be used to selectively provide air under pressure for removing the labels 19 from the conveyor belt 35, and the arrangement shown is merely illustrative. As shown in FIG. 3, two air manifolds 65 are mounted on a back wall 66 of the housing 31. Each of the manifolds 65 is of identical construction and has a plurality of ports 67, each of which is adapted for connection to one end of a flexible tube 69. The other end of each of the flexible tubes 69 is coupled to a rigid tube 71. The other end of the rigid tubes 71 can be slidably received within any of the apertures 63. When the valve 47 (FIG. 1) is opened, fluid under pressure flows from the valve 47 through the manifolds 65, the ports 67, the associated flexible tubes 69, the rigid tubes 71, the apertures 63, and the slots 51 to the exterior of the label transport 15. The pattern of the air blast can be selected by inserting the rigid tube 71 into selected ones of the apertures 63. The manifold and tube construction shown herein may be similar or identical to the construction shown in common assignee's U.S. Pat. No. 3,885,705.
The present invention also provides means for positively and accurately positioning the labels 19 on the conveyor belt 35 so that the labels will be in the correct positions to be applied to the articles 45 therebelow. Although various positioning arrangements and devices can be used, the present invention positions the labels 19 on the conveyor belt 35 in two ways. First, during the time that the labels 19 are being deposited on the belt 51 and being positioned, the movement on the conveyor belt 35 is continuous, and the movement of the backing strip 17 over the peeling bar 29 is intermittent. Intermittent movement of the backing strip 17 can be accomplished by appropriately starting and stopping the drive rollers 25 in a manner well known in the labeling applicating art. By properly relating the speed of movement of the conveyor belt 35 and the length of time that the backing strip 17 is at rest, the labels 19 can be roughly positioned and spaced on the conveyor belt 35.
In fact, if it is desired to employ very accurate controls, the timing of the continuous movement of the conveyor belt 35 and the intermittent movement of the backing strip 17 would alone be sufficient to properly space and position the labels 19 on the conveyor belt 35. However, in the embodiment illustrated, this only provides rough positioning of the label 19 on the conveyor belt 35.
Fine or accurate positioning of the labels 19 is provided for by three pairs of stops in the form of pins 73, 75, and 77. Each of the pins 73, 75, and 77 is adapted to project through a slot 79 in the plate 61 and through one of the slots 51. Each of the pins 73, 75, and 77 is movable between an extended or actuated position in which it projects into the path of movement of the labels 19 on the conveyor belt 35 and a retracted or unactuated position in which it is out of the path of movement of the labels 19 on the conveyor belt 35. Although this motion of the pins can be brought about in different ways, in the embodiment illustrated it is accomplished by air cylinders 81, one of which is provided for each of the pins. The pins are carried by the cylinders 81, respectively. The air cylinders 81 are mounted in groups of two on L-shaped brackets 83 which are in turn suitably mounted on the back wall 66. The brackets 83 are preferably mounted to allow the position of the brackets, the cylinders 81, and the associated pins to be adjusted. This can be accomplished, for example, by a slot 85 in each of the brackets 83 and suitable threaded fasteners 87. The slots 79 in the plate 61 allow the pins 73, 75 and 77 to be moved.
The air cylinders 81 are double acting. Although the air cylinders can be controlled in different ways, in the embodiment illustrated, each of them receives air under pressure from a four-way valve 89 to simultaneously move the pins 73, 75, and 77 between the extended and retracted positions. As each of the pins is individually controlled by one of the cylinders 81, the pins can be extended and retracted according to any desired program.
In operation of the label applicator 11, the drive rollers 25 (FIG. 1) operate intermittently to intermittently move the backing strip 11 over the peeling bar 29. During each period of intermittent motion, the peeling bar 29 removes one of the labels 19 from the backing strip 17 and deposits such removed label at a depositing station at the left end (as viewed in FIG. 3) of the exterior belt surface 55 of the conveyor belt 35. The differential pressure created by the suction force from the vacuum pump 33 acts through the apertures 63 and the slots 51 to hold each of the labels 19 deposited on the belt 35 against the exterior belt surface 55. The belt 35 is driven by the motor 60 through the clutch and brake 62 to advance each of the labels 19 deposited thereon away from the depositing station and along a label path. The pins 73, 75 and 77 are in the retracted position so they do not interfere with movement of the labels 19 along the conveyor belt 35.
After the first label 19 is deposited on the conveyor belt 35, the drive rollers 25 stop the backing strip 17 for a predetermined period of time to allow the first label 19 to advance away from the depositing station. At the end of this predetermined period, the drive rollers 25 are started to move the backing strip 17 to deposit a second label 19 on the belt 35. The operation described above is repeated to deposit a third label on the conveyor belt 35. The intermittent movement of the backing strip 17 and the continuous movement of the belt 35 are synchronized and controlled to roughly space the three labels 19 on the belt 35. This results in the labels 19 on the belt 35 being spaced further apart than when the labels were in the backing strip. The conveyor belt 35 advances the three labels 19 toward their final positions on the belt 35, i.e. the positions from which these labels will be removed from the belt.
Prior to the time that the labels 19 reach their final positions and after the second label 19 has passed by the axis of the pins 73, the air cylinders 81 are actuated by the four-way valve 89 to move the pins 73, 75, and 77 to the extended position shown in FIG. 4. The manner in which the four-way valve 89 may be caused to actuate the cylinder 81 at the proper time will be apparent to those skilled in the art and may be accomplished in a variety of ways. For example, the valve 89 may actuate the cylinders 81 a predetermined period of time after any event in the cycle of operation, such as a predetermined time after the first label 19 is deposited on the belt 35. Alternatively, the valve 89 can actuate the cylinders 81 a predetermined period of time after the third label 19 is deposited on the belt 35.
The pins are moved simultaneously to the extended position, and ultimately the first, second and third labels contact the pins 77, 75 and 73, respectively, whereupon movement of the labels along the conveyor belt 35 is arrested. The belt 35 continues to move for a short period after movement of the three labels 19 is terminated, and the belt and labels slip relative to each other. The clutch and brake 62 may be appropriately automatically controlled so that a predetermined period after the valve 89 causes the pins 73-77 to move to the extended position, the clutch is disengaged and the brake is engaged to stop the belt 51 while allowing the motor 60 to continue running. The belt 51 moves continuously in the sense that its movement is continuous from prior to the time that the first of the labels 19 is deposited thereon until all three labels are correctly positioned. A predetermined period after the belt 51 stops, the valve 89 is operated to cause the cylinders 81 to simultaneously retract the pins 73-77.
When the conveyor 37 brings the three articles 45 beneath the labels 19 on the belt 35, a product signal from a photocell, or other means known in the label applicating art, is provided in accordance with conventional practice. Appropriate control logic, the nature of which is apparent to those skilled in the art, is responsive to the product signal to open the valve 47 to provide a blast of air through the manifolds 65, the tubes 69 and 71, the apertures 63, and the slots 51 of sufficient force to simultaneously blow the three labels 19 from the conveyor belt 35 and onto the articles 45, respectively, to adhesively attach the labels to the articles. The labels 19 can be blown off of the belt 35 according to any program desired.
The drive rollers 25 are driven intermittently in accordance with a predetermined timed program to deposit the three labels on the belt 35 and then stop. This timed program is repeated following each opening of the valve 47 to deposit three additional labels 19 on the belt 35. Similarly, the clutch of the clutch and brake unit 62 is engaged and the brake of that unit is disengaged a predetermined short interval after the valve 47 opens to restart the belt 35. The sequencing of these functions, as well as the other control functions described herein can be readily implemented, either automatically or manually, by those skilled in the art.
Although an exemplary embodiment of the invention has been shown and described, many changes, modifications and substitutions may be made by those with ordinary skill in the art without necessarily departing from the spirit and scope of this invention. | A movable conveyor belt having first and second belt surfaces and an opening extending between the belt surfaces, a mechanism for depositing a label on the first belt surface at a first station, and a pressure source for blowing air under pressure through the opening to transfer the label from the belt at a second station to at least one object. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to an apparatus for detecting arcing faults, and more specifically, to such an apparatus for detecting arcing faults on low-voltage spot networks.
2. Description of the Prior Art
Low-voltage electrical power networks consist of interlaced loops or grid systems. Electrical energy is supplied to the network by two or more power sources, so that the loss of any one source does not result in an interruption of electrical service. These systems provide the highest level of reliability possible with conventional power distribution and are normally used to serve high-density load areas. Primary applications are in central or downtown city areas, large buildings, shopping centers, and some industrial plants. Network systems are of either the grid-type or spot-type. The electrical service is three-phase, three-wire or three-phase, four-wire at 208Y/120V or 480Y/277V.
In a grid system, the loads and sources form a grid pattern. Several sources, each usually employing a dedicated feeder, supply electrical power to the network. The source is connected to the network via a high voltage switch, a three-phase network transformer, and a network protector. The transformer secondary is usually 208Y/120V or 480Y/277V wye-connected, for three-phase, four-wire service to the network through the network protector. The network protector consists of an air circuit breaker, and normally a network master relay. When a source of supply or primary feeder is lost, the load formerly supplied by that feeder is carried by the remaining feeders.
Large concentrated load areas, such as commercial buildings and shopping centers, are frequently served by spot networks. Spot networks consist of two or more network units fed by two or more primary feeders. Typically, the spot network primary cables are tapped from non-dedicated feeders.
Typical low-voltage spot network installations operated at nominal 480Y/277V (line-to-line voltage grounded wye configuration) are not protected against network faults. Normally, a 480V bus is supplied by multiple transformer installations connected to two or more high-voltage primary circuits. Between the transformer and the 480V bus work is a network protector. The network protector isolates the transformer from the bus in the event of a fault in the transformer or the primary circuit feeding it. High reliability is achieved since primary faults are isolated and the network is carried by the other feeders connected to it.
The network protector also opens when a fault in the primary feeder would cause power flow from the network to the feeder, that is, reverse power flow. The network protector is not designed to open for faults on the network itself. In turn, fuses in the network are designed with a long time delay to act as back-up protection for the network protector for primary system faults. In addition, the master relay of the network protector opens the circuit breaker when the primary feeder is disconnected from its source of supply and magnetizing current flows from the secondary network into the network transformer. To summarize, the circuit breaker opens when the network transformer associated with it is not delivering power to the network, and when conditions are such that total three-phase power would flow from the network into the primary feeder. To protect against reverse power flow, the network master relay monitors total three-phase power direction. Typical spot network installations do not contain phase overcurrent or ground overcurrent protective relays or any form of overcurrent protection for the network, other than the fuses.
Phase-to-ground or phase-to-phase faults that start in the 480V bus work due to contamination, human error, etc. normally involve a power arc. The voltage produced across the arc can limit the fault current to values less than the rating of the network fuses in the bus work and can typically be on the order of the load current. Under such conditions, the network fuses will not open. However, these power arcs represent a tremendous concentration of energy at the point of the arc and the heat released represents a hazard and can destroy 480V bus work.
SUMMARY OF THE INVENTION
The present invention is a new protective relay designed to detect power arcs on spot networks and open all network protectors associated with the spot network, thereby extinguishing the power arc. To perform this function, the protective relay analyzes the harmonic distortion of the bus current or voltage. Oscillograms from staged arcing fault tests reveal that significant harmonic distortion of the phase-to-neutral voltage exists during a phase-to-ground power arcing fault. Harmonic distortion of the phase-to-phase and phase-to-neutral voltages also occurs during a phase-to-phase arcing fault. Harmonic distortion of the current in the faulted phase conductors also occurs.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be better understood, and further advantages and uses thereof more readily apparent, when considered in view of the following detail description of exemplary embodiments, taken with the accompanying drawings in which:
FIG. 1 is a block diagram of a low-voltage spot network including a first embodiment of a protective relay constructed according to the teachings of the present invention;
FIG. 2 is a block diagram of a low-voltage spot network including a third embodiment of a protective relay constructed according to the teachings of the present invention; and
FIG. 3 is a block diagram of a low-voltage spot network including a fourth embodiment of a protective relay constructed according to the teachings of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to FIG. 1, there is shown a block diagram of a low-voltage spot network 10 including a protective relay 11 constructed according to the teachings of the present invention. A three-phase high voltage is input to the primary winding (not shown) of a three-phase transformer 12. A secondary winding of the three-phase transformer 12 is connected to phase A, B, and C conductors via a network protector 14 and fuses 24, 26, and 28, respectively. A bus 20 comprises the phase A, B, and C conductors and a neutral conductor 22. The three-phase transformer 12 is connected to the neutral conductor 22; the neutral conductor 22 is grounded at several points. As illustrated, there is a voltage of 480V between the phase A and B conductors, between the phase B and C conductors, and between the phase A and C conductors.
Another high voltage source supplies power to the primary winding (not shown) of a three-phase transformer 16 via phase A, B, and C conductors. The secondary of the three-phase transformer 16 is connected to an input side of the network protector 18; an output side of the network protector 18 is connected to the phase A, B, and C conductors via fuses 30, 32, and 34, respectively. A three-phase transformer 16 is also connected to the neutral conductor 22, which is grounded at several points. The bus 20 is connected to a plurality of loads, as indicated in FIG. 1. The phase A, B, and C conductors are connected to a first load via fuses 36, 38, and 40, respectively. The phase A, B, and C conductors are also connected to a second load via fuses 42, 44, and 46.
The protective relay 11 includes a voltage sensor 48 adapted for connection to the phase A, B, and C conductors and the neutral conductor 22. The voltage sensor 48 produces three voltage signals representative of the voltages between the phase A conductor and the neutral conductor 22, between the phase B conductor and the neutral conductor 22, and between the phase C conductor and the neutral conductor 22. The three signals from the voltage sensor 48 are input to filters 50. The filters 50 represent three individual filters, one each for the three signals from the voltage sensor 48. The filters 50 are of a high-pass nature allowing only the higher harmonics to pass through. These harmonics are present on the voltage signals when there is a phase-to-phase or phase-to-ground power arc on the bus 20. The three signals from the filters 50 are input to harmonic detectors 52. The harmonic detectors 52 represent three independent harmonic detectors for analyzing the harmonics in each of the three signals from the filters 50. When any of the three signals from the filters 50 reaches a predetermined magnitude, as determined by the design of the harmonic detectors 52, the harmonic detectors produce a signal for activating an alarm 54 and for opening the network protectors 14 and 18, thereby removing power from the bus 20 and extinguishing the arc.
The harmonic detectors 52 measure the total harmonic distortion (THD) associated with each of the three signals from the filters 50. Where: ##EQU1## V i =RMS value of the ith harmonic Although no universal standards exist, electric utilities may allow a THD of about 5% on their system. Therefore, in one embodiment of the present invention the harmonic detectors 50 are designed to indicate a fault when the THD is approximately 10% on any one of the three voltage signals developed by the voltage sensor 48. A THD of this magnitude would reveal a power arcing fault on the bus 20.
In a second embodiment (not shown) of the protective relay 11, the voltage sensor 48 can be connected to the phase A, B, and C conductors in such a manner as to provide three signals, representative of the voltage between the phase A and B conductors, between the phase A and C conductors, and between the phase B and C conductors. This embodiment is intended to detect phase-to-phase power arcs. Operation of the filters 50 and the harmonic detectors 52 is the same in both embodiments. For complete bus protection, a protection scheme should include both the first and second embodiments of the protective relay 11.
FIG. 2 is a block diagram of the low-voltage spot network 10 including a third embodiment for the protective relay 11. The components of FIG. 2 are identical in structure and function to the components bearing identical reference characters in FIG. 1. FIG. 2 includes a current transformer 56 for providing a signal representative of the current on the phase A conductor; a current transformer 58 for providing a signal representative of the current on the phase B conductor; and a current transformer 60 for providing a signal representative of the current on the phase C conductor. The signals from the current transformers 56, 58, and 60 are input to the filters 50. As in the FIG. 1 embodiment, the filters 50 represent three individual filters for filtering the signals input thereto. The filtered signals are input to the harmonic detectors 52 for detecting harmonics indicating the presence of a power arc on the bus 20. When a power arc occurs, the harmonic detectors 52 produce a signal to activate the alarm 54 and open the network protectors 14 and 18.
FIG. 3 is another block diagram of the low-voltage spot network 10 illustrating a fourth embodiment for the protective relay 11. The components of FIG. 3 are identical in structure and function to the components bearing identical reference characters in FIG. 1. The FIG. 3 embodiment includes the current transformers 56, 58, and 60, but in this embodiment the current transformers 56, 58, and 60 are connected such that the signals therefrom are input to a zero-sequence network 62 for producing a signal representative of the zero sequence current on the bus 20. The zero sequence current signal is input to the filter 50 for filtering, and then to the harmonic detector 52 for determining whether harmonics indicating the presence of a power arc are present in the current signals. If a power arc is detected, the harmonic detector 52 produces a signal for activating the alarm 54 and opening the network protectors 14 and 18.
In both the embodiments of FIGS. 2 and 3, for complete protection of the low-voltage spot network 10, a protective relay, similar in structure and function to the protective relay 11 (including the current transformers 56, 58 and 60) must be located at the low-voltage terminals of both the three-phase transformers 12 and 16. This avoids the possible occurrence of a fault down stream from the protective relay 11, such that the protective relay 11 could not detect the fault. | A protective relay for detecting power arcing faults on a three-phase electrical power spot network. A phase-to-phase power arc on a spot network produces harmonics on the phase-to-phase voltages, and the phase currents; a phase-to-ground arc produces harmonics on the phase-to-neutral voltages. The protective relay of the present invention monitors one or more of the three phase-to-phase voltages, the three phase-to-neutral voltages, or the three phase currents and indicates a fault based on the harmonic content of those signals. | 7 |
FIELD OF THE INVENTION
The invention generally relates to fluid suction containers and in particular, to locking caps used with the pour spout of such containers.
BACKGROUND OF THE INVENTION
Typically a fluid suction container is used in a medical application such as an operating room environment to draw excess fluids away from a surgical field whether such fluids are medical fluids used to irrigate the surgical fluid or the patient's own excess body fluids.
One form of the suction container is a hard plastic canister having a removable cover thereon, with an air-tight seal between the cover and the canister so as to allow a vacuum to be operable within the canister to facilitate the withdrawal of excess fluids from the surgical field.
Because the canister is rigid and must be of sufficient strength to withstand the vacuum forces operative within the canister during its period of use, the cover is a point of weakness for the canister and must be designed to have sufficient strength and rigidity to prevent it from being drawn into the canister under the vacuum forces in use. Moreover, it is desirable that the cover have means therein to dispose of the fluid collected in the canister during its use in the medical procedure involved.
Because use of a rigid canister required the disposal of medical fluids collected therein, and sterilization after each usage, an alternative configuration for a suction container was proposed. In such alternative configuration a flexible canister liner was attached to a cover to be mounted on a rigid canister with such cover still maintaining sealing means with respect to the canister to assure the integrity of the vacuum provided in the rigid canister. In the alternative container configuration employing a hard cover attached to a flexible liner, such vacuum means is first used to draw the flexible container to its full volume before initiating fluid suction. The vacuum then applies suction to draw excess fluids from the surgical field into the flexible liner during the medical procedure involved, and then the cover and attached liner are removed from the rigid canister for disposal. And, such suction container comprising a rigid cover and a flexible liner can be disposed of after a single usage.
However, whether a suction container cover only is mounted on a rigid canister or the suction cover and its attached flexible liner is mounted on the rigid canister, it may be necessary to dispose of medical fluids after the medical procedure is performed through a pour spout in the cover. In both instances, the pour spout must be positively closed during the medical procedure to enable a vacuum condition for suction within the container and then capable of being opened for pouring of collected fluids from the container for disposal. With PVC cover materials it was possible to use a threaded cap and pour spout to secure the cap on the pour spout in fluid-tight and air-tight engagement. However, for many hospitals it is desirable to use something other than PVC materials for disposable containers, and typically such other materials are incapable of providing a threaded fluid-tight, air-tight connection.
In some instances, it is not necessary to reopen a suction container for disposal of fluids held therein, since many hospitals will incinerate waste containers, fluids and all. However, a substantial number of hospitals prefer to dispose of waste fluids and suction containers separately.
SUMMARY OF THE INVENTION
Accordingly, it would be desirable to provide a pour spout and cap combination which is usable with a preferred manufacturing material for suction containers such as polyethylene. The spout and cap combination are capable of being securely locked in fluid-tight, air-tight engagement for use in waste fluid suction procedures and then capable of being opened to separately dispose of the containers and the waste fluids in the containers.
Accordingly, the present invention provides a cover of sufficient strength to be mounted on a rigid canister, the cover receiving at an inner end a flexible canister liner for waste fluids attached to the cover in air-tight engagement, such cover including a pour spout and cap combination lockable in fluid-tight, air-tight engagement.
The pour spout should include a tubular body, opened at both ends and having at an inner surface thereof a segmented thread, each segment including a ramp and a stop, the segments equally spaced at 90 degree intervals. The complementary engaging cap should have a tubular body which snugly fits into the tubular body of the pour spout with equi-spaced ramps complementary to the locking segments of the pour spout for firmly locking the cap in place on the pour spout. Additional features of the cap would include support vanes or ribs to add structural integrity to the cap, and an oversized gripping surface indented to provide gripping segments for manual or automated gripping to rotate the cap into looking engagement on the pour spout.
A better understanding of the present invention can be obtained by considering the drawings briefly described below with the detailed description of the preferred embodiment which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a flexible container mounted on a rigid shell also showing a first tubing section connecting the flexible container to a vacuum source and a second tubing section connecting the container to a patient;
FIG. 2 is an exploded perspective view showing the flexible container including a portion of the liner as well as a closing cap associated with the pour spout and separated therefrom;
FIG. 3 is a bottom plan view taken along the lines 3--3 of FIG. 3;
FIG. 4 is a sectional view taken along the lines 4--4 of FIG. 3;
FIG. 5 is a sectional view taken along the lines 5--5 of FIG. 3;
FIG. 6 is an exploded sectional elevation taken along the lines 6--6 of FIG. 8 in which the pour spout and the locking cap are separated;
FIG. 7 is a view similar to FIG. 6 in which the locking cap is mounted in place on the pour spout; and
FIG. 8 is a top plan view of the locking cap mounted and closed onto the pour spout.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIGS. 1 and 2 is shown the flexible container 10 used as a receptacle for waste fluid in the operating room. The flexible container 10 comprises a cover 20 and flexible liner 50 received in a rigid shell or canister 60. The liner 50 and rigid canister 60 are discussed in greater detail below.
The cover 20, better seen in FIGS. 3-5, is a one piece molded construction of relatively rigid material such as polyethylene. Typically, polyethylene and similar plastics are not good choices for threaded parts because slippage occurs between joined parts, and it is difficult to achieve an air-tight, fluid-tight connection when polyethylene threaded parts are joined. The cover 20 includes an upper face 22 and lower face 24.
Shown on the lower face 24 (FIGS. 4 and 5) are a pair of annular flanges 25 and 26 which will be described in more detail below. The upper face 22 of the cover 20 includes a central support cylinder 27 closed at its upper face as at 28. The support cylinder 27 is concentric with the center of cover 20 and is 1.50 inches in diameter, slightly larger than one-third the diameter of the cover, which is 4.38 inches in diameter.
The upper face 22 of the cover 20 also includes an outer ring 30 displaced from central cylinder 27. The ring 30 overlies the inner annular flange 25 and outer annular flange 26 on the lower face 24 of the cover. The upper face of the ring 30 is disposed slightly below the upper face 28 of the central cylinder 27. At an outer edge of ring 30 is a downwardly extending outer annular wall 33. Outer annular wall 33 is also disposed adjacent outer flange 26. An annular bead 33a is also provided at the lower edge of the outer wall 33 to provide increased structural integrity under vacuum conditions.
Extending radially from the center of cover 20 to the inner edge of the first lower annular flange 25 are a plurality of equi-spaced ribs or vanes 31. At an edge 32 where the vanes 31 extend through the central cylinder 27, the vanes are the same height as the central cylinder. However, the vanes 31 are triangular in shape, with a base 31a (FIG. 5) engaging the central cylinder 27, and tapering in width as each vane extends from its base engaging the central cylinder to the inner edge of the outer ring 30 of the cover 20 to terminate at a point 34 (FIG. 5) at an inner edge of the ring 30.
Disposed between adjacent vanes 31 are cover segments 35 which begin at the inner edge of outer ring 30 and project inwardly and downwardly to engage the central cylinder 27 at a lower edge thereof.
The central cylinder 27 is also truncated at two sections. At section 36, the first of these truncated sections, a vacuum port 37 is disposed on a widened segment 35a, about midway between the rim 30 and the truncated portion 36. Vacuum port 37 protrudes above the widened segment 35a which has no vane 31 on its upper surface.
The vacuum port 37 extends above the cover 20 to about the height of the central cylinder 27. Port 37 includes a shoulder 37a disposed in the upper plane of segment 35a. On the lower face 24 of the cover 20 opposite the vacuum port 37 is a cylinder or skirt 39 (FIG. 4) which will be described in more detail below. Opposite the vacuum port 37 on the upper face 22 of the cover 20 is a tubular patient port 41, which intersects a vane 31 between adjacent segments 35 and is about 0.30 inches in diameter and extends about 1.00 inches above the outer ring 30 of the cover.
About midway between the vacuum port 37 and the patient port 41 is a second truncation 42 of the central cylinder 27. A widened segment 35b receives a pour spout 43 which is slightly larger than 1.00 inches in diameter and extends above the upper face 22 of the cover 20 about 0.60 inches.
At the lower face 24 of the cover 20, vanes 31 protrude slightly below lower face 24 and terminate at inner flange 25. Flanges 25 and 26, and flange 26 and outer wall 33, respectively, define annular spaces 25a and 26a therebetween. Inner annular space 25a receives the flexible liner 50 which is disposed against an outer face 51 of flange 25 and is fastened against face 51 of flange 25 in fluid-tight, air-tight engagement, as by welding. Annular space 26a, between outer flange 26 and outer wall 33 is provided for a purpose described in detail below.
The cylindrical skirt 39 of vacuum port 37 is slightly larger than 1.00 inches in diameter and is slightly longer than 1.00 inches. An upper extension of skirt 39 truncates central cylinder 27 at section 36. Skirt 39 holds a non-mechanical valve therein which will not be described in detail since it is not the subject of the present invention. The skirt 39 also includes a plurality of spaced structural vertical vanes (not shown) extending downwardly from the lower face 24 of cover 20.
The patient port 41 at its lower end includes a semi-circular splash guard 41a whose outer edge faces the vacuum port 37 and extends about 0.50 inches below the lower face 24 of the cover 20.
The tubular pour spout 43 terminates at the lower face 24 of the cover 20 and its lower edge slopes upwardly continuously with the segment 35b. The pour spout 43 is shown in more detail with its overlying cap 45 in FIGS. 6 through 8.
The tubular pour spout 43 includes a series of locking segments 44a equi-spaced on an inner face 44 of the pour spout 43. There are four locking segments 44a on inner face 44 of the pour spout 43, and they are disposed 90 degrees apart.
Each locking segment 44a includes a ramp 44b and a stop 44c at inner face 44 thereof. Complementary locking elements 46a are disposed on the outer periphery of a tubular body portion 46 of the cap 45. The tubular body portion 46 of the cap 45 fits into the tubular pour spout 43 to assure an air-tight, fluid-tight interface when the locking cap is locked in place on the pour spout. Each locking element 46a is ramp-shaped and in complementary conformance to the ramp 43b of each thread segment.
An outer gripping portion 47 of the cap 45 is fluted to provide multiple grip areas 47a at the outer edge of the cap 45 to enable manual or automated gripping. It would be desirable to use an automated gripping mechanism to engage locking cap 45 on pour spout 43 for closing during manufacture. Cap 45 can also be attached to the cover 20 by a link. A holding ring 49 at the end of link 48 may be attached to the cover 20 as at patient port 41. Actually, it is preferable that the link or holding ring 49 be mounted on elbow 52 inserted in the vacuum port 41, to better retain the link on the cover since the elbow 52 is not removed from the cover once vacuum tubing 63 is in place. However, to better display all of the structural elements of the invention, the link 49 was attached to patient port 41 in FIGS. 1-2.
The cover 20 is installed onto a waste canister 60 as follows. The waste canister 60 (FIG. 1) is a rigid canister body formed of a clear plastic such as a polycarbonate. It is also useful for the waste canister 60 to have volume markings on it to show the amount of fluid collected. Typically, those markings are in milliliters, and thus, satisfies both U.S. and foreign needs.
The flexible suction container 10, comprising the cover 20 and the flexible liner 50, is extended to its full length and fully inserted into the canister 60. The cover 20 is then snapped onto the canister 60, trapping the upper cylindrical edge of the canister 60 in space 26a between cover outer wall 33 and annular flange 26 to mount the cover 20 on the canister in air-tight engagement.
With the cover 20 firmly in place, the canister vacuum source is connected by tubing 65 to the right side of a tee fitting 62. The vacuum source is then activated to cause the flexible liner 50 to be drawn tightly against the inner face of the canister 60. Then the lid liner tubing 63 is attached to the left side of the tee at one end and to elbow 52 at an opposite end. Elbow 52 is then inserted into the vacuum port 37. A proximal end of patient tubing 64 is attached to the patient port 41 for fluid suction. The vacuum generated during fluid suction is typically 20 inches of mercury, but the suction container is operable at a vacuum of 10 inches of mercury.
The process of removing the liner from the canister begins with the vacuum turned on. First, the lid liner tubing 63 is detached from the canister tee fitting 62 with a downward twisting motion. Then the patient tubing 64 is detached from patient port 41. Then the lid liner tubing 63 is re-attached to patient port 41. Then the vacuum is turned off. Then, using thumb pressure on a tab 66 provided at a lower edge of cover 20, the cover 20 is loosened from the canister 60 and removed.
Following removal of the suction container 10 from the canister 60, the collected waste fluids can be disposed of by unlocking the cap 45 from the pour spout 43 to dispose of the waste fluid separately from the suction container, or the suction container and waste fluids may be disposed of together by leaving the system intact.
While the present invention has been disclosed with respect to the preferred embodiment, those of ordinary skill in the art will understand that further modifications may be made within the scope of the claims that follow. Accordingly, it is not intended that the claims be limited by the disclosure of the preferred embodiment, but that the scope of the invention be determined solely by reference to the claims.
The embodiment of the invention in which an exclusive property or privileges is claimed is defined as follows: | A suction container usable to suction fluids from the surgical field in an operating room environment. The container has a rigid cover overlying a flexible body portion attached thereto, the cover including a pour spout having a tubular body portion, a segmented thread disposed on an inner wall as a tubular body, the thread having a plurality of spaced segments, each segment defining a ramp and a stop. A locking cap is provided for mounting on the pour spout, the locking cap having a complementary tubular body for insertion into the pour spout, with complementary spaced ramped locking elements disposed on an outer surface of the tubular body for engaging the thread segments in locking the cap on the pour spout in fluid-tight engagement. | 1 |
Background of the Invention
The present invention relates to thermosettable vinyl ester resinous compositions (e.g. sheet molding compound or SMC) and more particularly to new low profile additives therefor.
Vinyl ester resinous compositions are liquid thermosetting resins which are the reaction product of about equal amounts of a polyepoxide and an unsaturated monocarboxylic acid. These resins often are used in combination with fibrous reinforcement and inert fillers to manufacture composite structures often called sheet molding compound or SMC. One way to make such composite structures is to pre-mix the resin, filler, fibrous reinforcement, and other additives to form the molding compound. The molding compound then can be formed into the desired shape and cured in a heated, matched metal dye. An improvement in the process is chemical thickening of the relatively low viscosity liquid resin, e.g. with a Group II metal oxide or hydroxide and water, to form a high viscosity gel after the resin has been mixed with all other ingredients in the molding compound. This thickening or B-staging has several advantages. Unthickened molding compounds are sticky masses which are difficult to handle. After B-staging, they are firm solids whose surfaces are dry. In this form, they can be handled easily. During the molding operation, the molding compound flows within the dye set to fill the dye cavity. The increased viscosity of B-staged molding compounds inhibits segregation of the various components of the molding compound during flow and promotes compositional uniformity of the composite over the entire volume of the structure.
The advent of low shrink-low profile additives has led to a considerable growth in sheet molding compounds and bulk molding compounds, such as described above. Previous to the development of these additives, reinforced molded parts had rippled or undulating surfaces, which required laborious sanding operations or other corrective measures to obtain painted parts with a metal-like appearance. The low shrink-low profile additives exhibited great benefits to providing exceptionally smooth surfaces.
Polyether polyols have been used as anti-shrink or low profile control additives in unsaturated polyester systems (U.S. Pat. Nos. 4,472,544 and 4,483,963). U.S. Pat. No. 4,472,554 describes the usage of a very high level of acidified polyethertriol as the shrinkage control additive. U.S. Pat. No. 4,483,963 describes the reaction product of oligoester with unsaturated polyester as the low profile additive (LPA) for unsaturated polyester systems. In vinyl ester systems, polyether polyols also have been reported as being useful as low profile additives (U.S. Pat. Nos. 4,151,219, 4,347,343, and 4,824,919). Most of the molecular weights in compositions of prior art polyethers have disadvantages. For example, their molecular weights tend to be too low for good shrink control and most are not compatible with vinyl ester resins. Thus, there is a need in the art for LPAs that are compatible with vinyl ester resin (one phase) and maintain good mechanical properties and shrinkage control.
BROAD STATEMENT OF THE INVENTION
The present invention is directed to a thermosettable vinyl ester resinous composition and low profile additive. The improvement comprises the low profile additive comprising a non-gelling, saturated polyester formed from dibasic acid and an ethylene oxide/propylene oxide polyether polyol having an EO/PO molar ratio ranging from about 0.1 to 0.9. The polyester has an acid value of greater than about 10 and preferably has a molecular weight of greater than about 6,000. The EO/PO polyether polyol can be built on a combination of diol, triol or other compound with active hydrogen groups, so long as the LPA product does not gel.
Advantages of the present invention include LPAs especially adapted for use with vinyl ester resins. The novel LPAs are compatible with the vinyl ester resin as indicated by their exhibiting an ostensibly one-phase system. Yet another advantage is a vinyl ester resin/LPA system which exhibits good mechanical properties and shrinkage control. These and other advantages will be readily apparent to those skilled in the art based upon the disclosure contained herein.
DETAILED DESCRIPTION OF THE INVENTION
Referring initially to the ethylene oxide/propylene oxide (EO/PO) polyether polyol block copolymer component of the low profile additive (LPA) of the present invention, the molar ratio of EO to PO ranges from about 0.1 to about 0.9. Ethylene oxide and propylene oxide can be co-reacted to form the polyether polyol, or the polyether polyol can be built on a di- or tri-functional compound which contains groups reactive with ethylene oxide and propylene oxide. Such suitable groups include, for example, hydroxyl groups, thiol groups, acid groups, and amine groups. Accordingly, diols, triols, dithiols, trithiols, diacids, triacids, diamines, triamines and the like are suitable multi-functional compound which can be reacted with ethylene oxide and propylene oxide for synthesizing the EO/PO block copolymer of the present invention. Suitable such compounds include, for example, alkylene glycols, typically ranging from about 2 to 8 carbon atoms (including cycloalkylene glycols). Illustrative of such diols are ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-propanediol, 1,3-butanediol, 2,3-butanediol, 1,3-pentanediol, 1,2-hexanediol, 3-methyl pentane,1,5-diol, 1,4-cyclohexanedimethanol, and the like, and mixtures thereof. Diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, and the like additionally can be used as necessary, desirable, or convenient. Suitable tri-functional compounds include, for example, glycerin, trimethylol propane, pentaerythritol, and like triols; dithierythritol, dithiothritol, citric acid, trioxypropylene triamine, trioxyethylene triamine, and the like, and mixtures thereof.
In building the EO/BO block copolymer, it is important that the LPA does not gel, but remain a liquid, which requirement places molecular weight and branching restrictions on the block copolymer as those skilled in the art will appreciate. Additionally, the block copolymer should not contain ethylenic unsaturation in the backbone, as the examples will demonstrate.
The block copolymer then is reacted with a dibasic acid, which can be aliphatic or aromatic. Examples of dibasic acids well known in the polyester art include, for example, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebasic acid, dodecanedioic acid, isophthalic acid, orthophthalic acid, terephthalic acid, corresponding anhydrides, and the like, and mixtures thereof. Preferably, such suitable dicarboxylic acids contain from about 4 to 12 carbon atoms.
Generally, the temperature of esterification is maintained in the range of about 150°-230° C. and an esterification catalyst is used. Such catalysts are conventional and include, for example, titanium tetrachloride, zinc acetate, zinc oxide, stannous oxylate, dibutyl tin oxide, and the like. Conventional color stabilizers, e.g. trilauryl phosphite or the like, also can be included in the reaction mixture. The proportion of acid to EO/PO block copolymer is such that the resulting LPA has an acid value of greater than 10 and such value can range on up to about 30. Additionally, the molecular weight of the LPA is preferred to be over 6,000 with a useful range of molecular weight being up to about 60,000.
Referring to the vinyl ester resins, reference is made to the following citations: U.S. Pat. Nos. 3,564,074, 4,151,219, 4,347,343, 4,472,544, 4,483,963, 4,824,919, 3,548,030, and 4,197,390. These resin systems include a terminally unsaturated vinyl ester resin in admixture with at least one copolymerizable monomer. Generally, the resins are mixed with styrene for thermally cured reinforced articles, but for radiation cure other monomers are more preferable, including, for example, alkyl acrylates or hydroxy alkyl acrylates. Terminally unsaturated vinyl ester resins, as taught in the foregoing citations, are prepared by reacting about equivalent proportions of a polyepoxide and an unsaturated monocarboxylic acid wherein the resulting resin has terminal, polymerizable unsaturated groups. For example, two equivalents of methacrylic acid may be reacted with two equivalents of a polyepoxide resin to produce a vinyl ester resin. As stated above, vinyl ester resins are well known in the art as set forth in the citations set forth above. The proportion of inventive LPA incorporated into the vinyl ester resin generally ranges from about 5 to 20 weight parts per 100 weight parts of vinyl ester resin. The compounding of such vinyl ester resinous compositions is well known in the art and little more need be said with respect thereto here.
Additionally, additives incorporated into the vinyl ester resinous composition are conventional in nature. Accordingly, suitable curing agents, accelerating agents, and the like are incorporated. Reinforcement and inert additives and fillers such as glass, metal filings, and inorganic fillers such as sand or clay also are appropriate. Pigments, release agents, plasticizers, and the like also are used as is necessary, desirable, or convenient in conventional fashion.
The following examples show how the present invention has been practiced, but should not be construed as limiting. In this application, all percentages and proportions are by weight and all units are in the metric system, unless otherwise expressly indicated. Also, all citations are expressly incorporated herein by reference.
EXAMPLE 1
In order to prepare the inventive polyester LPA, 800 g of BASF-628 EO/PO block polyether polyol (typical properties: OH no. 24.5 mg KOH/gm, pH apparent 9.1, density @ 25° C. 8.5 lbs/gal, and Brookfield viscosity @ 25° C. 1,100 cps), 50 g of isophthalic acid, and 0.82 g of monobutyl tin oxide were charged into a 2-liter glass reactor. A nitrogen sparge was maintained in the reactor and the contents heated to 215° C. This reaction temperature was held until the acid value was determined to be between about 12 and 15. The reactor contents then were cooled to 150° C. and 13 g of phthalic anhydride were charged into the reactor. The reactor temperature was maintained at 150° C. for two additional hours. The acid value of the resulting polyester LPA was between about 20 and 25.
The reactor contents there were cooled to 140° F. Benzoquinone (0.23 g) was dissolved into 288.6 g of styrene and this mixture charged into the reactor. The resulting acid value of the reactor contents was between about 13 and 18. The resulting product was a 75% solution of the polyester LPA of the present invention in styrene. This solution will be used as the LPA in the remaining examples.
EXAMPLE 2
A thickenable vinyl ester resin suitable for SMC application was prepared in a two-liter resin kettle equipped with a stirrer, temperature controller, oxygen sparge tube, and condenser. Into the reactor was charged: an epoxy resin, 529.5 wt-parts of a glycidyl polyether of 2,2-bis(4-hydroxyphenyl) propane having M n =350 and an equivalent weight of about 170-190, 2,2-bis (4-hydroxyphenyl) propane (157.8 wt-parts), and tetramethylammonium chloride (0.54 wt-parts). This mixture was heated for one hour at 171° C. Thereafter, methacrylic acid (128.8 wt-parts), hydroquinone (0.927 wt-parts), and additional tetramethylammonium chloride (4.36 wt-parts) was added to the reactor and the combined mixture heated for three hours at 115° C. under a nitrogen/air sparge.
After cooling the reaction mixture, 547 wt-parts of styrene was added. The kettle then was heated to 76° C. and 13.6 wt-parts of maleic anhydride and 0.16 wt-parts of benzoquinone were added to the kettle. The reaction temperature then was maintained between about 76° and 80° C. for one-half hour. Thereafter, an additional 20.53 wt-parts of maleic anhydride were added to the kettle and the reaction temperature maintained at about 76°-80° C. for another half hour. The final acid value of the thickenable vinyl ester resin was 30.
EXAMPLE 3
Compositions were compounded from the vinyl ester resin of Example 2 and various LPAs from the prior art and Example 1. Samples were formulated to contain 10 PHR (wt-parts per 100 wt-parts of vinyl ester resin) of the LPA. The compatibility of the various LPAs with the vinyl ester resin were compared and the following results recorded.
TABLE 1______________________________________LPA OBSERVATION______________________________________ComparativeBASF-P-4010 propylene oxide diol 2 layersBASF-P-4040 propylene oxide triol 2 layersBASF-628 (EO/PO - 25/75) miscibleInventiveBASF-628/isophthalic acid polyester miscibleBASF-628/adipic acid polyester miscible______________________________________
The two prior art polyether polyols are unsuitable for use in preparing SMC due to their incompatibility with the vinyl ester resin. Both the isophthalic acid and adipic acid polyester versions of the inventive LPAs, however, were miscible with the vinyl ester resin as was the unmodified EO/PO polyether polyol.
EXAMPLE 4
In this example, various LPAs were compounded with the vinyl ester resin of Example 2 and shrinkage rates determined. The SMC formulation compounded is set forth below.
TABLE 2______________________________________Ingredient Amount (g)______________________________________Vinyl ester resin (60% in styrene) 212.5LPA (60% in styrene) 37.5t-butyl perbenzoate 3.75Zinc stearate 11.25CaCO.sub.3 250______________________________________
The formulations then were compression molded at 300° F. for 2 minutes at 600 psi. This shrinkage data and LPAs evaluated are set forth below.
TABLE 3______________________________________ LPALPA AMT (phr) % Shrinkage______________________________________ComparativeBASF-628 end capped with succinic 9 1.89anhydrideBASF-628 end capped with maleic 9 2.1anhydrideInventiveBASF-628/adipic acid polyester 9 1.1BASF-628/adipic acid polyester 12 0.8BASF-628/isophthalic acid polyester 12 0.88______________________________________
As the above-tabulated results demonstrate, the inventive LPAs provide substantially reduced shrinkage of the molded part compared to the comparative LPAs. Note the improvement at increasing levels of the inventive LPA.
EXAMPLE 5
Lower acid values of the inventive polyester LPAs can cause the separation of the SMC paste prepared from MgO thickened vinyl ester resinous compositions. An LPA formulated from BASF-628 and adipic acid to an acid value of 6 was prepared and mixed with the vinyl ester resin of Example 2 and then thickened with MgO. The thickened SMC paste separated after 1 day. When the same LPA candidate was formulated to have an acid value above 10, however, a stable and homogeneous one-phase SMC paste was obtained. Thus, the preference in the present invention for the inventive polyester LPA to have an acid value of greater than about 10.
EXAMPLE 6
In this Example, the effect of molecular weight of shrinkage control of the inventive LPAs was evaluated. The vinyl ester resin of Example 2 was compounded with 9 PHR of the various LPA candidates and the shrinkage of the resulting compression molded part (See Example 4) was determined.
TABLE 4______________________________________ MolecularLPA Weight % Shrinkage______________________________________ComparativeBASF-628 end capped with succinic 4,026 1.89anhydrideInventiveLPA of Example 1 8,164 1.15LPA of Example 1 13,510 1.05LPA of Example 1 22,100 1.03______________________________________
As the above-tabulated data demonstrates, all of the inventive LPAs provided improved shrinkage control compared to similar LPAs merely end-capped with acid functionality. With respect to the inventive LPAs, increasing molecular weights provided improved shrinkage control. Even at lower molecular weights, however, the inventive LPAs provide improved shrinkage control compared to prior art LPAs.
EXAMPLE 7
In this Example, the effect of both adipate and isophthalate LPAs on shrinkage control of glass reinforced vinyl ester SMC plaques was evaluated. The formulations compounded and the mechanical properties determined are set forth below.
TABLE 5______________________________________ Sample (wt-parts)Formulation A B C D______________________________________Vinyl Ester Resin (II) 97.3 82.7 85.95 82.7(60% solid in styrene)Polyester of polyether polyol 0 14.60 11.35 14.60LPA (I)(60% solids in styrene)Other additives 3.6 3.6 3.6 3.6T-Butyl Perbenzoate 1.5 1.5 1.5 1.5Zinc Stearate 4.5 4.5 4.5 4.5CaCO.sub.3 100 100 100 1001" Glass 113.6 113.6 113.6 113.6MgO thickening agent 4.0 4.0 4.0 4.0______________________________________ The quantities listed on the table above are by parts by weight.
TABLE 6__________________________________________________________________________ Sample (wt-parts) B C D 9 phr 7 phr 7 phr A Example I Example I Example IMechanical Property No LPA Isophthalate Isophthalate (Adipate)__________________________________________________________________________Flex Strength (psi) 33,800 25,987 29,740 30,123Flex Modulus (psi) 1.76 × 10.sup.6 1.38 × 10.sup.6 1.51 × 10.sup.6 1.56 × 10.sup.6Tensile Strength (psi) 16,360 12,838 14,555 14,171Tensile Modulus (psi) 1.96 × 10.sup.6 1.58 × 10.sup.6 1.62 × 10.sup.6 1.59 × 10.sup.6Elongation (%) 1.588 1.503 1.523 1.460H.sub.2 O Absorption 0.254% 0.365% 0.255% 0.214%Cold Mold/Cold Part -12 mil +2 mil -3 mil +1 mil12" × 12" plaque__________________________________________________________________________ += Expansion; -= Shrinkage
The formulations containing the inventive LPAs exhibited better shrinkage control than the comparative sample without any LPA added thereto. It will be observed that good mechanical properties were exhibited by the formulations containing the inventive LPAs.
EXAMPLE 8
This Example, illustrates the extent of the expansion that the inventive LPAs can achieve with various levels thereof. The SMC pastes were prepared and glass reinforced SMC plaques were molded and evaluated.
TABLE 7__________________________________________________________________________(wt-parts) Sample A Sample B Sample C Sample D Sample E 12 phr 18 phr 15 phr 12 phr 15 phrFormulation Adipate LPA Adipate LPA Adipate LPA Isophthalate LPA Isophthalate__________________________________________________________________________ LPAVinyl Ester Resin (II) 77.84 68.11 72.98 77.84 72.98[60% solid in styrene]Ester of Polyether Polyol 19.46 29.19 24.33 19.46 24.33LPA (I) [60% solid in styrene]Other Additives 3.6 3.6 3.6 3.6 3.6T-Butyl Perbenzoate 1.5 1.5 1.5 1.5 1.5Zinc Stearate 6.0 3.0 4.5 4.5 4.5CaCO.sub.3 100 100 100 100 100MgO Thickening Agent 3.0 3.0 3.0 3.0 3.01" Glass 113.6 113.6 113.6 113.6 113.6__________________________________________________________________________
TABLE 8__________________________________________________________________________(wt-parts) Sample A Sample B Sample C Sample D Sample E 12 phr 18 phr 15 phr 12 phr 15 phrFormulation Adipate LPA Adipate LPA Adipate LPA Isophthalate LPA Isophthalate LPA__________________________________________________________________________Flex Strength (psi) 27,510 16,820 22,570 25,540 17,810Flex Modulus (psi) 1.63 × 10.sup.6 0.95 × 10.sup.6 1.53 × 10.sup.6 1.63 × 10.sup.6 1.30 × 10.sup.6Tensile Strength (psi) 13,330 9,478 9,160 11,780 8,828Tensile Modulus (psi) 1.70 × 10.sup.6 1.31 × 10.sup.6 1.31 × 10.sup.6 1.60 × 10.sup.6 1.59 × 10.sup.6Elongation (%) 1.513 1.36 1.31 1.18 1.00Cold Mold/Cold Part +4 mil +10 mil +8 mil +7 mil +7 mil12" × 12" plaques__________________________________________________________________________ "+" = Expansion "-" = Shrinkage
As shown in the above-tabulated data, up to 10 mil expansion of SMC reinforced plaques can be achieved when high levels of LPA are used. | The present invention is directed to a thermosettable vinul ester resinous composition and low profile additive. The improvement comprises the low profile additive comprising a non-gelling, saturated polyester formed from dibasic acid and an ethylene oxide/propylene oxide polyether polyol having an EO/PO molar ratio ranging from about 0.1 to 0.9. The polyester has an acid value of greater than about 10 and preferably has a molecular weight of greater than about 6,000. The EO/PO polyether polyol can be built on a combination of diol, triol or other compound with active hydrogen groups, so long as the LPA product does not gel. | 2 |
FIELD OF THE INVENTION
The present invention relates generally to rotation rate sensors. Specifically, it pertains to rotation rate sensors with closed-ended dual tine tuning forks.
BACKGROUND OF THE INVENTION
Conventional rotation rate sensors typically employ double open ended (or H-shaped) tuning forks or single open ended tuning forks for sensing rotation. There are however a number of problems associated with these types of tuning forks.
Conventional open ended tuning forks have a complex structure in order to mechanically isolate them from the housing of the rotation rate sensor. This makes the associated manufacturing process complex and time consuming. Moreover, the complexity of the structure also increases the size of these tuning forks which in turn affects the number of tuning forks which can be produced per wafer of piezoelectric material.
Moreover, conventional open-ended tuning forks are mounted to the housing of the rotation rate sensor in such a way that strains are imparted on the tuning fork as the ambient temperature varies. These strains are due to the mismatch in coefficients of thermal expansion between the housing material and the piezoelectric material of the tuning fork and cause the drive mode and pickup mode vibration frequencies of the tuning fork to vary substantially from the desired frequencies of these modes.
Additionally, conventional open ended tuning forks have numerous vibrational modes below the drive and pickup modes. These vibrational modes can be easily excited by external vibrations and therefore affect the performance of the rotation rate sensor.
SUMMARY OF THE INVENTION
The foregoing problems are solved by a rotation rate sensor in accordance with the present invention. The rotation rate sensor includes a closed-ended tuning fork which has a drive end base, a pickup end base, and a pair of tines. Each of the tines has a drive end and a pickup end with the drive ends of the tines being integrally joined or connected to the drive end base and the pickup ends of the tines being integrally joined or connected to the pickup end base. The rotation rate sensor also includes a drive circuit for generating a drive signal and a plurality of drive electrodes disposed on the tines for applying the drive signal to the tines. The drive signal causes drive mode vibration of the tines. The drive mode vibration changes orientation when the tuning fork is rotated and causes pickup mode vibration of the tines. The rotation rate sensor further includes means for providing a pickup signal corresponding to the pickup mode vibration of the tines. It also includes a pickup circuit which is responsive to the pickup signal for generating a rate signal corresponding to the rate of rotation of the tuning fork.
BRIEF DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram of a rotation rate sensor having a closed-ended tuning fork in accordance with the present invention.
FIG. 2 is a top view of the closed-ended tuning fork employed by the rotation rate sensor of FIG. 1.
FIG. 3 is a bottom view of the closed-ended tuning fork of FIG. 2.
FIG. 4 provides an illustration of the temperature related pulling forces and counteracting forces distributed over the gimbals of the tuning fork of FIGS. 2 and 3.
FIG. 5 is an exterior side view of the tuning fork of FIGS. 2 and 3 along the line 5a-5b.
FIG. 6 is an interior side view of the tuning fork of FIGS. 2 and 3 along the line 6a-6b.
FIG. 7 is an interior side view of the tuning fork of FIGS. 2 and 3 along the line 7a-7b.
FIG. 8 is an interior side view of the tuning fork of FIGS. 2 and 3 along the line 8a-8b.
FIG. 9 provides an illustration of the shape of the drive mode vibration of the tuning fork of FIGS. 2 and 3.
FIG. 10 provides an illustration of the shape of the pickup mode vibration of the tuning fork of FIGS. 2 and 3.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a rotation rate sensor 10 which includes a closed-ended dual tine tuning fork 11. Referring to FIGS. 2 and 3, the tuning fork 11 is etched or otherwise formed (e.g., laser cut) from a single crystal of a piezoelectric material such as quartz. The orientation of the tuning fork 11 is defined by the X, Y, and Z axes. These axes correspond to the alignment of the molecular structure of the crystal, and in the embodiments of the invention, tuning fork 11 is oriented in the XY plane.
Tuning fork 11 includes a pair of tines 14 and 15, a drive end base 17, a pickup end base 18, a drive end suspension system 19, and a pickup end suspension system 20.
The tines 14 and 15 respectively have drive ends 22 and 23 and pickup ends 24 and 25. The drive ends 22 and 23 are integrally joined or connected to the drive end base 17 while the pickup ends 24 and 25 are integrally joined or connected to the pickup end base 18.
The drive and pickup end suspension systems 19 and 20 are integrally joined or connected to the drive and pickup end bases 17 and 18, respectively, and are affixed to the housing 12. Thus, the suspension systems 19 and 20 together suspendedly mount the tuning fork 11 to the housing 12.
The drive and pickup end suspension systems 19 and 20 each include a thin bridge 27 and a gimbal 28. Each bridge 27 is integrally and substantially perpendicularly joined or connected to one of the gimbals 28 and to one of the drive and pickup end bases 17 and 18.
Referring to FIG. 4, each gimbal 28 includes cross bars 30 and 31, side bars 32 and 33 and a mount 34. The cross bar 30 is integrally and substantially perpendicularly joined or connected to the bridge 27. The side bars 32 and 33 are integrally and substantially perpendicularly joined or connected to the cross bars 30 and 31. The mount 34 is integrally and substantially perpendicularly joined or connected to the cross bar 31 and is affixed to the housing 12.
The gimbals 28 serve to reduce strains imparted on the tuning fork 11 when the ambient temperature changes. This occurs in the following manner.
Referring again to FIGS. 2 and 3, when temperature changes, the suspension systems 19 and 20 are respectively subjected to stress at the portion of the housing 12 to which they are fixed. This is due to the mismatch in coefficients of thermal expansion between the material of the housing 12 and the piezoelectric material of the tuning fork 11. However, the resulting pulling or pushing forces and the forces counteracting the pulling or pushing forces are isolated on and distributed over the gimbals 28.
Specifically, referring to FIG. 4, pulling forces experienced by the drive and pickup end suspension systems 19 and 20 are effectively distributed over the gimbals 28 into two components F p1 and F p2 . The first component F p1 extends from the side bar 32 to the point where the mount 34 and the cross bar 31 are joined. The second component F p2 extends from the side bar 33 also to the point where the mount 34 and the cross bar 31 are joined.
Moreover, the force counteracting the pulling forces experienced by the drive and pickup end suspension systems 19 and 20 are also effectively distributed over the gimbals 28 into two components F c1 and F c2 . The first component F c1 extends from the side bar 32 to the point where the bridge 27 and the cross bar 30 are joined. The second component F c2 extends from the side bar 33 also to the point where the bridge 27 and the cross bar 30 are joined.
Referring again to FIGS. 2 and 3, since the temperature related strains are isolated on the gimbals, the strain on the drive end and pickup end bridges 27 is effectively eliminated. As a result, the tuning fork 11 is isolated from temperature boundary conditions and the drive, pickup, and other vibration modes of the tuning fork remain substantially at their desired resonant frequencies during changes in ambient temperature.
Furthermore, all of the piezoelectric elements of the tuning fork 11 (i.e, tines 14 and 15, end bases 17 and 18, and suspension systems 19 and 20) have the same thickness. Since this thickness is the thickness of the wafer of piezoelectric material from which the tuning fork 11 is formed, the process for forming the tuning fork 11 is greatly simplified. This substantially speeds up the processing time and reduces the cost of forming tuning fork 11.
Respectively located on the top and bottom surfaces 45 and 46 of tine 15 are two drive high electrodes 48 and 49. And, as shown in FIG. 5, located on the exterior side surface 54 of tine 14 is the drive high electrode 50. The electrodes 48 and 50 are connected together by the lead 55. Furthermore, as shown in FIG. 6, located on the interior side surface 56 of tine 14 are the parallel drive high electrodes 51 and 52. The electrodes 49, 51, and 52 are connected together by the lead 58 while electrodes 50-52 are connected together by lead 57. Thus, all of the drive high electrodes 48-52 are coupled together and to the lead 55.
Referring again to FIGS. 2 and 3, respectively located on the top and bottom surfaces 59 and 60 of tine 14 are two drive low electrodes 61 and 62. Turning to FIG. 7, located on the interior side surface 66 of tine 15 are the parallel drive low electrodes 63 and 64. The electrodes 61, 63, and 64 are connected together by the lead 67.
Furthermore, as shown in FIG. 8, located on the exterior side surface 68 of tine 15 is the drive low electrode 65. The electrodes 62 and 65 are connected together by the lead 70 while electrodes 63-65 are connected together by the lead 69. Thus, all of the drive low electrodes 61-65 are coupled together and to the lead 70.
Furthermore, turning to FIGS. 5 and 6, the two pickup high electrodes 72 and 73 are respectively located on the exterior and interior side surfaces 54 and 56 of tine 14. As shown in FIGS. 7 and 8, the other two pickup high electrodes 74 and 75 are respectively located on the interior and exterior side surfaces 66 and 68 of tine 15. The electrodes 72-75 are connected together by the lead 77.
Referring again to FIGS. 5 and 6, the two pickup low electrodes 79 and 80 are respectively located on the exterior and interior side surfaces 54 and 56 of pickup tine 14. The electrodes 79 and 80 are connected together by the lead 83. And, as shown in FIGS. 7 and 8, the other two pickup low electrodes 81 and 82 are respectively located on the interior and exterior side surfaces 66 and 68 of pickup tine 15. The electrodes 81 and 82 are connected together by the lead 84. Thus, the electrodes 7982 are all coupled together and to the lead 85.
As just described, on the interior side surface 56 of tine 14 are the two parallel drive high electrodes 51 and 52 and the parallel pickup high and pickup low electrodes 73 and 80. And, on the interior side surface 66 of tine 15 are the two parallel drive low electrodes 63 and 64 and the parallel pickup high and pickup low electrodes 74 and 81.
This type of split electrode configuration occurs because the close spacing of the tines 14 and 15 allows them to be used to create the necessary shadowing to produce the split electrode configuration during the metalization process. Thus, tuning fork 11 overcomes any metalization difficulties by design and does not require any other structural features or complication of tooling.
Referring back to FIG. 1, the rotation rate sensor circuit 13 of the rotation rate sensor 10 includes a drive circuit 90 and a pickup circuit 91.
The drive circuit 90 includes a current amplifier 93 and an automatic gain control (AGC) loop 94. As is well known in the art, the AGC amplifier 98 of the AGC loop 94 produces an oscillating drive high signal V DH . The drive high signal V DH is provided to the lead 55 and applied to the tines 14 and 15 by the drive high electrodes 48-52.
Furthermore, the current amplifier 93 receives the current signal I DL on lead 70 picked up by the drive low electrodes 61-65 from the tines 14 and 15. At the same time, the current amplifier 93 produces the drive low signal V DL in the form of a virtual ground on the lead 70 since the positive input of the operational amplifier 97 is grounded. The drive low signal V DL is provided to the electrodes 61-65 which apply it to the tines 14 and 15.
The applied drive high signal V DH and the drive low signal V DL cause strains in the piezoelectric material of the tines 14 and 15. These strains induce the tines 14 and 15 to vibrate generally in opposite directions in the XY plane at their resonant frequency in the drive mode, as shown in FIG. 9.
Referring back to FIG. 1, the drive mode vibration of the tines 14 and 15 cause oscillating electric field gradients to be created in the tines 14 and 15. The composite current signal I DL picked up from the tines 14 and 15 with the drive low electrodes 61-65 due to the oscillating field gradients is provided to the current amplifier 93, as was indicated earlier. In response, the current amplifier 93 amplifies the current signal I DL and outputs it to the AGC loop 94. The amplified current signal is proportional to the amplitude of vibration of the tines 14 and 15 in the drive mode.
The amplified current signal is then provided to the amplitude detector 96 and the AGC amplifier 98 of the AGC loop 94. The amplitude detector 96 rectifies the current signal and provides the rectified output to the AGC loop amplifier 99. In response, the AGC loop amplifier 99 outputs a signal which controls the AGC amplifier 98 to generate the drive high signal V DH so as to keep the amplitude of vibration of the tines 14 and 15 fixed. The voltage amplitude of the drive high signal V DH is therefore proportional to the amplitude of the vibration of the tines 14 and 15.
When tuning fork 11 is subjected to an inertial rotation about the Y axis, the tines 14 and 15 have a component of vibration due to this inertial rotation. In this case, the bridges 27 of the suspension systems 19 and 20 enable the tines 14 and 15 to experience generally equal but opposing Coriolis accelerations in planes parallel to the YZ plane. These time-varying Coriolis accelerations cause the drive mode vibration of the tines 14 and 15 to change orientation so that the tines 14 and 15 have vibrational components out of the XY plane and in planes parallel to the YZ plane at the resonant frequency of the drive mode. This is the pickup mode rotation induced vibration component of the tines 14 and 15 and is shown in FIG. 10. As a result, the Coriolis accelerations and displacements of the tines 14 and 15 in the planes parallel to the YZ plane are in phase with the velocity of the tines 14 and 15 in the XY plane and are linearly proportional to the inertial rotation about the Y axis.
Furthermore, partial vibration of the tines 14 and 15 in planes parallel to the YZ plane may be excited by the forced drive mode vibration of the tines 14 and 15. This partial vibration is known as the pickup mode quadrature vibration component of the tines 14 and 15 and is 90° out of phase (i.e., in quadrature) with the pickup mode rotation induced vibration component of the tines 14 and 15.
The quadrature vibration component may occur because tines 14 and 15 may not be perfectly mass balanced because of facets (i.e., unwanted material) left on the tines 14 and 15 from the etching process used in forming the tines 14 and 15. Moreover, the drive high electrodes 48-52 and the drive low electrodes 61-65 may not be perfectly aligned on the tines 14 and 15 which may also contribute to the quadrature vibration component.
As a result, quadrature creating accelerations and displacements of the tines 14 and 15 due to the factors just described exist in the planes parallel to the YZ plane. These accelerations and displacements of the tines 14 and 15 are (1) 90° out of phase (i.e., in quadrature) with the drive mode velocity of the tines 14 and 15 in the XY plane, and (2) 90° out of phase (i.e., in quadrature) with the displacement of the tines 14 and 15 in the YZ plane due to rotation of the tuning fork 11. Thus, as was stated earlier, the pickup mode quadrature vibration component of the tines 14 and 15 and is 90° out of phase (i.e., in quadrature) with the pickup mode rotation induced vibration component of the tines 14 and 15.
The pickup mode for rotation rate sensor 10 occurs anytime that the tines 14 and 15 vibrate in the planes parallel to the YZ plane at the same frequency as the drive mode vibration of these tines. Thus, the pickup mode involves both the quadrature vibration component and the rotation induced vibration component of the tines 14 and 15.
As shown in FIG. 1, a pickup low signal V PL in the form of a ground is provided by the pickup circuit 91 to the pickup low electrodes 79-82 via the lead 85. The pickup low signal V PL is applied to the tines 14 and 15 by the pickup low electrodes 79-82.
When the tines 14 and 15 vibrate in the pickup mode, strains are imposed on the piezoelectric material of the tines 14 and 15. These strains, together with the applied pickup low signal V PL , cause oscillating electric field gradients to be generated in the tines 14 and 15.
In response, the pickup high electrodes 72-75 together pickup a pickup high signal V PH from the tines 14 and 15. The pickup high signal V PH represents the summed together time-varying strain-induced charge created in the pickup tines 14 and 15. Moreover, this signal has a rotation induced component that corresponds to the rotation induced vibration component of tines 14 and 15 and a quadrature component that corresponds to the quadrature vibration component of tines 14 and 15.
The pickup high signal V PH is provided to the pickup circuit 91 via the lead 77. The pickup circuit 91 includes a charge amplifier 110, a bandpass filter 112, a synchronous demodulator 114, a low pass filter 116, and an output amplifier 118.
The charge amplifier 110 receives the pickup high signal V PH . In response, the charge amplifier 110 amplifies the signal and provides it to the bandpass filter/amplifier 112. The bandpass filter/amplifier 112 filters and amplifies this signal and provides it to the synchronous demodulator 114.
The synchronous demodulator 114 uses the signal output by the current amplifier 93 as a reference signal to remove or reject the quadrature component of the signal output by the bandpass filter/amplifier 112. As a result, it outputs a direct current (DC) rate signal that is proportional to the magnitude of the rotation induced component of the pickup high signal V PH . Since the rotation induced component is proportional to the Coriolis accelerations experienced by the drive tines 14 and 15 and therefore proportional to the rate of rotation of the tuning fork 11, the DC rate signal output by the synchronous demodulator 114 is also proportional to the rate of rotation of the tuning fork 11.
The low pass filter 116 receives the DC rate signal from the synchronous demodulator 114. It removes any residual high frequency components and provides the filtered signal to the output amplifier 118.
The output amplifier 118 amplifies the filtered DC rate signal and outputs it as the output rate signal V R . Since the output rate signal V R is proportional to the DC rate signal, the output rate signal V R is proportional to and represents the rate of rotation of the tuning fork 11.
One significant advantage to the employing the closed-ended tuning fork 11 in the rotation rate sensor 10 is that the tuning fork 11 is very insensitive to external vibrations. This insensitivity is due to the mechanical simplicity of the tuning fork 11. As a result, tuning fork 11 has a limited number of vibrational resonances in frequency ranges of practical interest.
For example, analysis reveals only two meachnical resonances below the drive natural frequency, the lowest typically having its resonance frequency greater than 40% of the drive mode natural frequency. Thus, if tuning fork 11 has a drive mode frequency of 12,500 Hz, its lowest frequency mode will be at or above 5,000 Hz, which is far above common externally applied vibrations of 2,000 Hz or less. This lack of low frequency modes means that tuning fork 11 will have negligible vibration sensitivity to typical applied vibration environments.
Another advantage provided by rotation rate sensor 10 is a low feedthrough (i.e., capacitive coupling of input to output) error. This is due to the placement of the drive electrodes 48-52 and 61-65 so that one end of each of these electrodes is located adjacent the drive ends 22 and 23 of the tines 14 and 15 and the placement of the pickup electrodes 72-75 and 79-82 so that one end of each of these electrodes is adjacent the pickup ends 24 and 25 of the tines 14 and 15. In other words, due to the separation of the drive electrodes 48-52 and 61-65 from the pickup electrodes 72-75 and 79-82, electrostatic field flux lines created with the drive electrodes 48-52 and 61-65 will not interfere with the pickup of the pickup high signal V PH , by the pickup electrodes 72-75.
Lastly, the simplicity of the design of tuning fork 11 makes it very compact. As a result, the number of tuning forks 11 that can be produced per wafer of piezoelectric material is maximized.
While the present invention has been described with reference to a few specific embodiments, the description is illustrative of the invention and is not to be construed as limiting the invention. Furthermore, various modifications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims. | A rotation rate sensor that includes a closed-ended tuning fork which has a drive end base, a pickup end base, and a pair of tines. Each of the tines has a drive end and a pickup end with the drive ends of the tines being joined to the drive end base and the pickup ends of the tines being joined to the pickup end base. The rotation rate sensor also includes a drive circuit for generating a drive signal and drive electrodes disposed on each of the tines for applying the drive signal to the tines. The drive signal causes drive mode vibration of the tines. The drive mode vibration changes orientation when the tuning fork is rotated and causes pickup mode vibration of the tines. The rotation rate sensor further includes pickup electrodes disposed on each of the tines for picking up a pickup signal corresponding to the pickup mode vibration of the tines and a pickup circuit which is responsive to the pickup signal for generating a rate signal corresponding to the rate of rotation of the tuning fork. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a U.S. national stage application of PCT/EP03/06786, filed Jun. 26, 2003, which PCT application is incorporated herein by reference in its entirety.
BACKGROUND
The present invention relates to a method for spinning a multifilament thread from a thermoplastic material comprising the steps of extruding the melted material through a spinneret with a plurality of spinneret holes to form a filament bundle comprising a plurality of filaments, winding the filaments as thread after solidifying, and cooling the filament bundle beneath the spinneret.
The present invention also relates to polyester filament yarns and cords which contain polyester filament yarns.
A method of this type is known from EP-A-1 079 008. The movement of freshly extruded filaments is supported during the spinning procedure by a stream of air. Cooling thus takes place essentially through a stream of cooling agent flowing parallel to the thread. Good results are generally achieved with this type of cooling, especially with high drawing-off speeds.
A two-step cooling method for spinning a multifilament thread from a thermoplastic material is disclosed in JP 11061550. In the first cooling zone, the air flow is directed in such a way that it reaches the filaments from one side or circumferentially, and in a second zone compressed air is blown into the upper section of the cooling zone so that there is a downward flow of air parallel to the filaments. The purpose of this is to produce filaments with physical properties that are as uniform as possible.
The cooling behavior of thermoplastic polymers is certainly complicated and dependent upon a series of parameters. Especially during the cooling process, differences in the double refraction might be created over the filament cross-section, since the filament skin cools faster than the inside of the filament, i.e., the filament core. This cooling process also leads to differences in the crystallization behavior of the filaments. The cooling thus determines the crystallization of the polymers in the filament to a large degree, which is noticeable in the later usage of the filaments, for example in drawing. It is desirable for a series of applications that a high degree of cooling is achieved as soon as possible after the extrusion, in order to encourage rapid crystallization.
The cooling processes of the prior art do not fulfill, or incompletely fulfill, these requirements.
SUMMARY
An object of the present invention is to provide a method for the effective cooling of extruded filaments, which thus leads to good crystallization, even at relatively low winding speeds.
The object is achieved with the method described herein in that the method is distinguished in that cooling is performed in two steps, the filament bundle being blown on with a gaseous cooling medium in the first cooling zone in such a way that the gaseous cooling medium flows through the filament bundle transversely and leaves the filament bundle practically completely on the side opposite the inflow side, and in a second cooling zone beneath the first cooling zone the filament bundle being cooled further essentially through self-suction of the gaseous cooling medium surrounding the filament bundle.
DETAILED DESCRIPTION OF EMBODIMENTS
The method thus deals with a two-step cooling procedure. In the first step, a gaseous cooling medium flows through the filament, and the cooling agent leaves the filament bundle practically completely on the side opposite the inflow side. In this step of the cooling process, the cooling medium should thus not be drawn along with the filament if possible. To execute this first cooling step, the gaseous cooling medium may be directed to flow through the filament bundle transversely to the direction in which the filament bundle is moving, so that a so-called transverse air flow is provided. This air flow can be effectively created by sucking off the gaseous cooling medium with a suction device after it has passed through the thread bundle. A well-directed cooling stream is thus achieved and it is ensured that the cooling agent quantitatively leaves the filament bundle. The design can thus be effected in such a way that the filament bundle is guided between a blowing device and a suction device, for example. Another possibility would be to split the filament flow and to place a blowing device mid-way between two filament flows for example, such as through a perforated tube running parallel to and between the filament flows for a certain distance. The gaseous cooling medium can then be blown from the center of the filament bundle through the filament bundle to the outside. Again, it is important to ensure that the cooling medium leaves the bundle practically completely.
Of course, creating the air flow and suction in the other direction is also possible, for example by having the tube running through the center of the filament streams serve as a suction device and the blowing then takes place from outside to inside.
In the method of the invention, it is preferred for the flow speed of the gaseous cooling medium to be between 0.1 and 1 m/s. At these speeds, a uniform cooling mostly without intermingling or creation of skin/core difference during crystallization can be achieved.
Further, it has proven to be completely adequate if the first cooling zone has a length between 0.2 and 1.2 m.
Blowing over these lengths and under the conditions described above, the desired degree of cooling in the first zone or step is reached.
The second step of cooling is carried out using the so-called “self suction yarn cooling” wherein the filament bundle pulls the gaseous cooling medium in its proximity, such as the ambient air, with it and thus cools further. In this case the gaseous cooling medium flows mostly parallel to the direction in which the filament bundle is moving. It is important that the gaseous cooling medium reach the filament bundle from at least two sides.
The self-suction unit can be created with two perforated panels, so-called double-sided panels, running parallel to the filament bundle. The length is at least 10 cm and can be up to several meters. Common lengths for these self-suction distances range from 30 cm to 150 cm.
In the method of the invention, it is preferred that the second cooling step be performed in such a way that by conducting the filaments between perforated materials, such as perforated panels, the gaseous cooling medium can reach the filaments from two sides during the self suction.
Conducting the filament bundle in the second cooling zone through a perforated tube has proven to be advantageous. Such self-suction tubes are known to those skilled in the art. They make it possible to pull the gaseous cooling medium through the filament bundle in such a way that intermingling can be mostly avoided.
It is possible to regulate the temperature of the cooling medium sucked through the filament bundle by using heat exchangers, for example. This embodiment allows a process control independent of the ambient temperature, which is advantageous for the continued stability of the process, in day/night or summer/winter differences for example.
Between the spinneret, or the nozzle plate, and the beginning of the first cooling zone there is usually a so-called “heating tube.” Depending upon the type of filament, the length of this element, which is known to those skilled in the art, is between 10 and 40 cm.
Between the first and second cooling zones, a bundling step can further be advantageously implemented in a form known per se, e.g., using the so-called airmover or airknives. This bundling step can also take place within the second cooling zone.
The process according to the invention of course can include drawing of the filaments in a form known per se after the cooling zones and prior to winding. The term ‘drawing’ here includes all common methods known to those skilled in the art, to draw the filaments. This can be done with a single or double roll, or something similar. It must be explicitly mentioned that drawing refers to drawing ratios greater than 1 as well as ratios less than 1. The latter ratios are known to one skilled in the art under the term relaxation. Drawing ratios greater and less than 1 can occur together within one process.
The entire drawing ratio is usually calculated from the ratio of the drawing speed or, if a relaxation also takes place, the winding speed at the end of the process and the spinning speed of the filaments, i.e., the speed with which the filament bundles pass through the cooling zones. As an example, a spinning speed of 2760 m/min, drawing at 6000 m/min, with additional relaxation after the drawing of 0.5%, i.e., a winding speed of 5970 m/min, results in a total drawing ratio of 2.16.
The preferred winding speeds according to the invention are therefore at least 2000 m/min. In principle there are no top speed restrictions for the process within what is technically possible. In general, however, a top speed for winding of 6000 m/min is preferred. For the common total drawing ratios of 1.5 to 3, the spinning speed thus lies in the range of around 500 to around 4000 m/min, preferably 2000 to 3500 m/min.
Further, a quenching cell can be located upstream of the drawing device and after the cooling zones. This element is also known per se.
For the gaseous cooling medium, air or an inert gas such as nitrogen or argon is preferred.
The method of the invention is in principle not restricted to certain types of polymers and can be applied to all types of polymers that are extrudable to filaments. Polymers, such as polyester, polyamide, polyolefin, or mixtures or copolymers of these polymers, are preferred as thermoplastic material, however.
It is especially preferred that the thermoplastic material consists essentially of polyethylene terephthalate.
The method of the invention allows the production of filaments particularly suitable for technical applications, especially for use in tire cords. Moreover, the method is suitable for the fabrication of technical yarns. The necessary design for spinning technical yarns, in particular the selection of the nozzle and the length of the heating tube, is known to one skilled in the art.
The invention is therefore also directed to filament yarns, in particular polyester filament yarns, which are obtainable with the method described above.
The present invention is particularly directed to polyester filament yarns with a breaking tenacity T in mN/tex and an elongation at rupture E in %, for which the product of the breaking tenacity T and the cube root of the elongation at rupture E (T*E 1/3 ) is at least 1600 mN % 1/3 /tex. It is preferred that this product is between 1600 and 1800 mN % 1/3 /tex.
The measurements of the breaking tenacity T and the elongation at rupture E to determine the parameter T*E 1/3 are performed according to ASTM 885 and are known to one skilled in the art.
In a preferred embodiment, the invention is directed to polyester filament yarns, for which the sum of their elongation in % after applying a specific load EAST (elongation at specific tension) of 410 mN/tex and their hot-air shrinkage at 180° C. (HAS) in %, thus the sum of EAST+HAS, is less than 11%, preferably less than 10.5%.
Measurement of the EAST is performed according to ASTM 885, and the HAS is measured as well according to ASTM 885 on the condition that the measurement is conducted at 180° C., at 5 mN/tex, and for 2 minutes.
Finally, the present invention is directed to tire cords, which contain polyester filament yarns and in which the cord has a retention capacity Rt in %, the tire cords being distinguished in that the quality factor Q f , i.e. the product of T*E 1/3 of the polyester filament yarns and Rt of the cord, is greater than 1350 mN % 1/3 /tex.
The retention capacity is to be understood as the quotient of the breaking tenacity of the cord after dipping and the breaking tenacity of the threads.
It is especially preferred to have a quality factor greater than 1375 mN % 1/3/ tex, and advantageously up to 1800 mN % 1/3 /tex.
The invention will be further explained with the help of the following examples, without being restricted to these examples.
EXAMPLES
Polyethylene terephthalate granules with a relative viscosity of 2.04 (measured with a solution of 1 g polymer in 125 g of a mixture of 2,4,6-trichlorophenol and phenol (TCF/F, 7:10 m/m) at 25° C. in an Ubbelohde viscometer (DIN 51562)) was spun and cooled under the conditions listed in Table 1. The drawing speed was 6000 m/min. An additional relaxation of 0.5% was set, with a winding speed of 5970 m/min.
TABLE 1
Yarn count [dtex]
1440
Filament linear density [dtex]
4.35
Spinneret
331 holes; diameter
of 800 μm each
Length of the heating tube [mm]
150
Temperature in the heating tube [° C.]
200
Length of the first cooling zone [mm]
700
Air flow volume [m 3 /h]
400
Length of the second cooling zone [mm],
700
double-sided panel
Temperature of the cooling air [° C.]
50
Bundling
Airmover
The yarn properties were determined on three samples and are shown in Table 2.
TABLE 2
Example 003
Example 004
Example 005
Spinning speed [m/min]
2791
2759
2727
Breaking tenacity T
688
703
712
[mN/tex]
Elongation at rupture E
13.9
13.7
12.9
[%]
Strength at an
388
341
348
elongation of 5%
TASE5 [mN/tex]
T * E 1/3 [mN % 1/3 /tex]
1654
1682
1670
Finally, the cord properties were determined after dipping and are summarized in Table 3.
The quality factor Qf is calculated as the product of T*E 1/3 and the retention.
TABLE 3
Example 003
Example 004
Example 005
Breaking tenacity T
589
595
604
[mN/tex]
Strength at an elongation
227
223
222
of 5% TASE5 [mN/tex]
T * E 1/3 [mN % 1/3 /tex]
1654
1682
1670
Retention capacity Rt
85.6
84.6
84.8
[%]
Quality factor
1416
1424
1417
[mN % 1/3 /tex]
Elongation under a
5.9
5.8
5.7
specific force of
410 mN/tex EAST [%]
Hot-air shrinkage (HAS)
4.2
4.5
4.3
[%]
EAST + HAS [%]
10.1
10.3
10.0 | A method is provided for spinning a multifilament thread from a thermoplastic material, including the steps of extruding the melted material through a spinneret with a plurality of spinneret holes into a filament bundle with a plurality of filaments, winding the filaments as thread after solidifying, and cooling the filament bundle beneath the spinneret, whereby in a first cooling zone the gaseous cooling medium is directed in such a way that it flows through the filament bundle transversely, the cooling medium leaving the filament bundle practically completely on the side opposite the inflow side, and in a second cooling zone beneath the first cooling zone, the filament bundle being cooled further essentially through self-suction of the gaseous cooling medium surrounding the filament bundle. | 3 |
RELATED APPLICATIONS
This application is a Continuation of International Application No. PCT/IL2007/001317, filed on Oct. 30, 2007, which in turn claims the benefit under 35 USC 119(e) of U.S. Provisional Application No. 60/855,143, filed on Oct. 30, 2006, both of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to a system and method for in vivo measurement of biological parameters of a subject.
BACKGROUND OF THE INVENTION
Near infrared spectroscopy (NIRS) is a well-established non-invasive technique which allows for the determination of tissue and blood analytes conditions based on spectrophotometric measurements in the visible and near-infrared regions of the spectrum of light. According to this technique, incident light penetrates the examined skin, and reflected and/or transmitted light is/are measured. In order to quantify any blood analyte, light of at least two different wavelengths is required. Optical plethysmography, pulse oximetry, and occlusion spectroscopy are the most prominent examples of usage of the NIR spectroscopy in medicine and physiological studies.
Visible or near infrared light is commonly used to track the optical manifestation of some time-dependent physiological processes. Such prolonged measurement of light response as a function of time can provide clinician with valuable information about time-dependent physiological processes.
For example, the measured light response of a natural heart beat pulsation is varied with each pulse. The signal is then measured at one point of the pulse wave and compared with the signal at another point. The difference between the values is due to arterial blood alone. In the pulse-oximetry, this phenomenon is utilized for the determination of oxy-hemoglobin saturation.
In the case of occlusion spectroscopy, the optical time-dependent signal is originated by light scattering changes associated with the red blood cells (RBC) aggregation process. In this case, the optical signal changes are utilized for the hemoglobin or glucose measurement.
Yet another known method enables to generate the required changes is the application of a periodic or non-periodic local pressure variation, resulting in blood volume fluctuations. These fluctuations are used to measure different blood parameters, like hemoglobin or glucose.
The major underlying assumption in the processing of all kind of the time-dependent signals is that the measured optical variation is originated solely by blood related components. In pulse oximetry, for example, it's commonly accepted that arterial blood volume changes are the only responsible factor staying behind the optical signal modulation. However, a more complex physical analysis shows that even if the only changes in the system are ascribed to the blood, the measured optical response of these changes is a convolution of absorption and scattering properties of blood and surrounding media. While carrying out any algorithmic modeling and signal processing procedure of these measured optical signals, the tissue related effects can not be disregarded. Therefore, the common denominator of all time-dependent signal related optical methods relies on the measurement of optical responses originated by the blood dynamics or hemorheological status changes.
It should be noted that the accuracy of time-dependent methods depends on the ability to identify the hemorheological component of the blood. For example, in the particular case of pulse-oximetry, the heart beats modulate the hemorheological status of circulating blood, resulting in the fluctuation of RBC velocity, which is associated with the shear forces changes. The variation of the hemorheological blood parameters enables to optically distinguish the pulse-related changes of the signal. Therefore, the decreased accuracy in the determination of hemorheological properties leads to a lower accuracy in the determination of the sought blood parameter. Among the blood parameters which can be derived from the hemorheological changes are hemoglobin oxygen saturation, carohyhemoglobin (percentage of HbCO out of total hemoglobin), hemoglobin blood concentration and/or glucose.
Moreover, the arterial blood pressure is another physiological parameter, which is commonly derived from the hemorheological related variations. The systolic blood pressure can be determined with assistance of inflating cuff which induces hemorheological variations artificially. When a pressure beyond the systolic pressure is applied, no pulsatile waveform appears at the down-flow. The diastolic point of the pressure is frequently measured by using Korotkoff's sounds. The source of these sounds is associated with abrupt changes in hemorheological properties of blood, occurring due to deflation of cuff from the systolic point. These hemorheological changes, in the vicinity of the diastolic point, result in a very typical pattern of sound, which can be detected by a stethoscope or by other acoustic device. However, the sound related method is very sensitive to different motion artifacts and therefore in automatic blood pressure devices, commonly used for the self-monitoring, the accuracy of blood pressure reading is impaired.
SUMMARY OF THE INVENTION
There is a need in the art in facilitating in vivo measurements of rheological parameters of a subject, by providing a novel measurement technique. This is associated with the two major problems related to time-dependent optical methods for the measurement of hemorheological processes.
Firstly, the method of detecting hemorheological changes optically has a quite restricted sensitivity. Since the currently used method of optical measurement detects only scattering or absorption related changes of the signal, when the aggregation factor not vary, the scattering and absorption remain unchanged and hemorheological fluctuations remain unmeasured. For example, the measured optical signal has few ranges of low sensitivity with respect to the blood velocity changes. The limitation comes into force where the blood flow value is very high and, consequently, RBC aggregation process is prevented by very strong shear forces. Moreover, when the blood flow is very weak and the RBCs have already aggregated, the blood flow changes can not affect the aggregation status.
Secondly, in the currently used technique, there is a problem in the reduction of motion artifacts. Most of the motion artifacts interfering with time-dependent measurements are removed based on fact that the characteristic time constants are different from slow, motion related interferences. When the motion artifacts characteristic appearance is in the close vicinity to the signal appearance (for example, 1 Hz of the heart beat interference with 1.1 Hz of the bounce of the running person), the hemorheological signal is almost undistinguishable from the artifact.
The novel technique of the present invention enables to differentiate clearly between the blood-originated and tissue-related signals, reduce the problem of motion artifacts, determine at least one desired parameter or condition of a subject such as hemorheological (blood rheology) related parameters, for example apparent blood and blood plasma viscosity, red blood cells (RBC) aggregation, blood flow or blood coagulation properties, and based on these rheological parameters to determine chemical parameters of blood, such as oxygen saturation, hemoglobin, or glucose concentrations and physiological system parameters, like blood pressure and blood flow.
Moreover, there is a need in performing an accurate blood pressure measurement by measuring hemorheological properties changes optically, using more robust and noise resistant method.
As indicated above, the conventional techniques remove most of the motion artifacts interfering with pulse measurements, using characteristic time constants of heart beats which are different from slow motion related interferences. However, other types of motion artifacts interfering with pulse measurements, such as patient shivering, can not be removed by such techniques. This type of artifact is indistinguishable from the signal generated by pulse, due to the analogous characteristic time constants shared between pulse frequency and the frequency of the body shivering. Another example of indistinguishable motion artifact is associated with walking or running activities, where the characteristic frequencies of the motion pattern may overlap the heart rate frequency ranges. The last fact is considered as a great obstacle in utilization of the photoplethysmography or like for the heart rate measurements during the sport or walking activities.
The present invention solves the above problems by providing a novel optical technique suitable for the in vivo measurement in a subject utilizing dynamic light scattering (DLS) approach. More specifically, the present invention utilizes the effect of DLS for the measurement of variety of blood related parameters, like viscosity of the blood and blood plasma, blood flow, arterial blood pressure and other blood chemistry and rheology related parameters such as concentration of analyte (e.g. glucose, hemoglobin, etc.), oxygen saturation etc.
DLS is a well-established technique to provide data on the size and shape of particles from temporal speckle analysis. When a coherent light beam (laser beam, for example) is incident on a scattering (rough) surface, a time-dependent fluctuation in the scattering property of the surface and thus in the scattering intensity (transmission and/or reflection) from the surface is observed. These fluctuations are due to the fact that the particles are undergoing Brownian or regular flow motion and so the distance between the particles is constantly changing with time. This scattered light then undergoes either constructive or destructive interference by the surrounding particles and within this intensity fluctuation information is contained about the time scale of movement of the particles. The scattered light is in the form of speckles pattern, being detected in the far diffraction zone. The laser speckle is an interference pattern produced by the light reflected or scattered from different parts of an illuminated surface. When an area is illuminated by laser light and is imaged onto a camera, a granular or speckle pattern is produced. If the scattered particles are moving, a time-varying speckle pattern is generated at each pixel in the image. The intensity variations of this pattern contain information about the scattered particles. The detected signal is amplified and digitized for further analysis by using the autocorrelation function (ACF) technique. The technique is applicable either by heterodyne or by a homodyne DLS setup.
According to one broad aspect of the invention, it provides a system for use in non-invasive determination of at least one desired parameter or condition of a subject having a scattering medium in a target region. The system comprises an illuminating system including at least one source of partially or entirely coherent light to be applied to the target region in said subject to cause a light response signal from the illuminated region; a detection system including at least one light detection unit configured for detecting time-dependent fluctuations of the intensity of the light response and generating data indicative of the a dynamic light scattering (DLS) measurement; and, a control system configured and operable to receive analyze the data indicative of the DLS measurement to determine the at least one desired parameter or condition, and generate output data indicative thereof. The data generated by the detection system is indicative of fluctuation dependent speckle pattern of the light response over a predetermined frequency interval.
In some embodiments, the control system is configured and operable for analyzing the received data by using temporal autocorrelation intensity analyzing or power spectrum analyzing. The control system may be configured and operable analyze the received data, to reject low frequency component of the received data, and process high frequency components of the received data, thereby enabling elimination of motion artifacts. The control system comprises: a data acquisition utility responsive to the generated data coming from the detection system; a modulating utility associated with the illuminating system; a data processing and analyzing utility for analyzing data from the data acquisition utility and determine at least one hemorheological and blood chemical parameter; a memory utility for storing coefficients required to perform predetermined calculation by the data processing and analyzing utility, and an external information exchange utility configured to enable downloading of the processed information to an external user or to display it.
According to some embodiments of the invention, the system comprises a controllably operated pressurizing assembly configured and operable to affect a change in a blow flow, the control system comprising a control utility associated with the pressurizing assembly.
The system may comprise fiber optics for collecting the light response signal and delivering it to the detection system.
According to some embodiments of the invention, the system having at least two light sources operable at different wavelength ranges. The illuminating system is adapted to produce light of red and near infrared spectral regions, enabling assessment of the arterial blood oxygen saturation and/or in blood hemoglobin determination.
The system may be configured and operable to create an intermittent blood stasis state by applying over systolic blood pressure to the subject, thereby enabling the determination of red blood cell (RBC) aggregation.
In some embodiments, at least one light source of the illumination system is coupled with a polarization unit enabling to create polarized electromagnetic signal in one preferable direction. An entrance of at least one of detection units of the detection system is also coupled with a polarization unit, such that the polarization unit enables only certain direction of pre-selected polarized radiation to be detected increasing the signal to noise ratio.
According to another broad aspect of the invention, the present invention provides medical tool for carrying out non-invasive measurement and/or treatment on a patient's body. The medical tool comprises an illuminating system generating partially or entirely coherent light to be focused on a target region in the body, and a detection system configured for detecting time-dependent fluctuations of the intensity of the light response and generating data indicative of a dynamic light scattering (DLS) measurement.
According to yet another aspect of the invention, the present invention provides an optical method for use in determining in vivo hemorheological chemical and physiological parameters of a subject. The method comprises generating a partially or entirely coherent light; applying the light to a target region in the subject; detecting fluctuation dependent speckle pattern of the light response over a predetermined frequency interval and generating data indicative thereof, processing the detected data by using the temporal autocorrelation intensity analyzing or the power spectrum analyzing; and, determining at least one desired parameter or condition of the subject from the time-fluctuation of a dynamic light scattering (DLS) signal.
In some embodiments, the method comprises rejecting low frequency component of the detected DLS signal by using high-pass filters; and processing high frequency components to eliminate motion artifacts.
The chemical parameter comprises at least one of the following: a blood viscosity, an average size of RBC aggregates, and blood coagulation properties.
In some other embodiments, the method comprises creating temporal blood flow cessation at the measurement region to measure a post-occlusion signal. The method comprises analyzing the measured post-occlusion signal to determine blood plasma viscosity and a rate of RBC aggregation.
In some other embodiments, the method comprises illuminating the target region with light of red and near infrared spectra, thereby enabling for measuring simultaneously the DLS signal at two or more wavelengths to determine at least one of the following: arterial blood oxygen saturation, blood hemoglobin concentration, and glucose concentration.
According to yet another aspect of the invention, the present invention provides an optical method for determining in vivo arterial blood pressure of a subject. The method comprises applying partially or entirely coherent light to a target region in the subject to cause a light response signal from the target region; applying a controllable pressure to the subject so as to induce hemorheological variations artificially; detecting fluctuation dependent speckle pattern of the light response signal over a predetermined frequency interval and generating data indicative thereof, processing the detected data by using temporal autocorrelation intensity analyzing or power spectrum analyzing; and, determining systolic and diastolic arterial blood pressure values from the time-fluctuation of the DLS signal.
According to yet another aspect of the invention, the present invention provides an optical method for determining in vivo heart pulse rate of a subject. The method comprises applying a partially or entirely coherent light to a target region in the subject to cause a light response signal from the target region; detecting fluctuation dependent speckle pattern of the light response over a predetermined frequency interval, and generating data indicative thereof; processing the detected data by using temporal autocorrelation intensity analyzing or power spectrum analyzing; and, determining the heart rate pulsation from the heart beat time fluctuation of the DLS related parameter.
The above and other features of the invention including various novel details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular method and device embodying the invention are shown by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles of the invention. Of the drawings:
FIG. 1 is an illustration of a DLS measurement based system according to the teachings of the present invention;
FIG. 2 is a schematic illustration of a simultaneous measurement of the transmission signal using photodetector D 2 and of the reflection signal using photodetector D 1 ;
FIG. 3 is a schematic illustration of the use of an optical fiber-based system;
FIG. 4 is a graphical illustration of a raw data of pulse being collected and measured from the finger tip by the DLS system;
FIG. 5 is a graphical illustration of a change of a normalized function at measurement onset (0.5 sec) and after 20 sec of over systolic occlusion as measured on the finger tip by the DLS;
FIG. 6 is a logarithmic scale graphical presentation of the same;
FIG. 7 is a graphical presentation of the power spectrum used to process the measured signal by using a standard Fast Fourier Transformation (FFT) digital signal processing algorithm;
FIG. 8 is a graphical presentation of the time variation of the full integral of the power spectrum during an 80 sec duration measurement section, which is presented in terms of the energy power spectrum;
FIG. 9 is a graphical presentation of the time variation of the full integral of the power spectrum during the first 10 seconds of the pulsatile signal;
FIG. 10 is a graphical presentation of the power spectrum integral upon the frequency interval [0-550 Hz];
FIG. 11 a - b are graphical presentations of the power spectrum integral upon the frequency interval [2700-10000 Hz];
FIG. 12 is a graphical presentation of the power spectrum integral upon the frequency interval [1-1.6 KHz];
FIG. 13 a is a graphical presentation of the power spectrum integral in the post-occlusion pulsatile sessions (80-86 sec) upon the frequency interval [0-2150 Hz];
FIG. 13 b is a graphical presentation of the power spectrum integral in the post-occlusion pulsatile sessions (80-86 sec) upon the frequency interval [2700-10000 Hz];
FIG. 14 is a graphical presentation of the pulsatile and post occlusion signals presented in terms of A(tn) and B(tn) of polynomial coefficients;
FIG. 15 is a graphical presentation of a DLS related parameter (d(ln(G)/dt)) utilized for the determination of systolic and diastolic blood pressure;
FIG. 16 is an imaging of a laser temporal speckle contrast K t inside occluded blood vessels;
FIG. 17 is an imaging of a laser temporal speckle contrast K t inside occluded blood vessels and laser irradiation;
FIG. 18 is a graphical presentation of a DLS measurement utilized for the determination of the oxygen saturation changes; and,
FIG. 19 is a graphical presentation of the measured pulsatile component of the blood in terms of d(ln(AUT)/dτ.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is made to FIG. 1 illustrating a DLS measurement based system 100 implementing the present invention. System 100 includes a light source unit 10 (e.g. laser) for generating at least partially coherent light; optical arrangement (not shown) including focusing optics and possibly also collecting optics; and a detection unit 16 . A focused beam of light 12 produced by laser 10 (e.g., a He—Ne laser) is used as a localized light source. In a non-limiting example, a light source unit 10 may be a laser diode (650 nm, 5 mW) or VCSEL (vertical cavity surface emitting laser). The light response i.e. the reflected and/or transmitted light returned from the localized region of the subject's surface 14 (patient's finger in the present example) illuminated with the localized light source 10 , can be collected in a determined distance L (in a non-limiting example, L=100 mm) either directly by a detector or via multimode fiber optics. In a non-limiting example, the multimode fiber optics may be a bifurcated randomized optical fiber where one optical entrance is connected to the detector and another one is optically coupled with the laser diode. In particular, as shown in FIG. 1 , system 100 includes at least one laser diode 10 and at least one photodetector (photodiodes) 16 appropriately positioned in the reflection-mode measurement set-up.
As exemplified in FIG. 2 , the system may be operable to implement simultaneous measurement of the transmission signal using photodetector D 2 and reflection signal using photodetector D 1 . This can be used for a relatively transparent (for the respective wavelength range) subject (i.e. like through a subject's finger tip 14 ). It should be noted that generally, the system may be operable in either one of transmission and reflection modes or both of them.
FIG. 3 exemplifies the use of an optical fiber-based system 200 having a somewhat different configuration. One of the advantages of optical fiber-based system 200 lies in the maximum flexibility of such system for non-invasive measurement of subjects. The use of randomized optical fiber secured geometric stability and the small effective distance between light source 10 and detector 16 is responsible for a high signal to noise ratio. It should be noted that the same fiber optic bundle 36 can be used for both the collection of the signal from the measured subject and the delivery of the coherent radiation towards the subject to be measured. Further provided is a control system having an electronic unit 32 and a data processor and analyzer (CPU) 34 . The electronic unit 32 is configured and operable to reject a low frequency component of the detected signal by using high-pass analog filters, and process only high frequency components to strongly amplify them, digitize them, and pass to the control unit (CPU) 34 for further digital processing. This approach enables the required sensitivity and dynamic range to be increased which is essential to account for only DLS related component of the measured signal. In a non-limiting example, the data is collected at 22 KHz sampling rate and 16-bit resolution.
The kinetics of optical manifestations of two kinds of physiological signals is measured in vivo: the pulsatile signal associated with heart beats and the post-occlusion optical signal which is induced by an artificially generated blood flow cessation. The light transmission and/or reflection signals are used as a control of the physiological response. This kind of control measurement can be carried out simultaneously with the DLS reflection measurement. The mutual correspondence between DLS and standard optical signals is subject to a comparison analysis.
The following is an example of analysis of pulsatile and post-occlusion signals. Reference is made to FIG. 4 showing an example of raw data of pulse (AC signal variation with time) which is collected and measured from a finger tip by DLS system 100 . The low frequency components of the signal are rejected by an analog filter of electronic box 32 . Subsequently, the signal is amplified and digitized for further analysis.
Generally, two standard approaches are commonly applicable to an analysis of DLS signals. The first approach uses the temporal autocorrelation of the intensity, and the second approach entails the analysis of the power spectrum P(w) of the detected signal.
According to the first approach, the formula for the correlation function G(τ) of temporal intensity fluctuations of light scattered by moving particles is given by:
G ( τ ) = 〈 I ( t ) · I ( t + τ ) 〉 〈 I ( t ) 〉 2 [ 1 ]
where I(t) is the intensity at time t and < . . . > denotes an ensemble average. It has to be taken into consideration that for preferable configuration of measurement system 100 , the intensity of the signal I(t) already lacks zero and low frequencies components of the signal (0-100 Hz), which are already removed by the high-pass analog filter of the electronic box 32 .
When the measured signal is converted from an analog to digital form, the autocorrelation function is calculated by using a summation, averaging over N sampling points given by the following expression:
〈
G
(
τ
)
〉
=
(
1
/
N
)
∑
i
=
k
k
+
N
I
(
k
)
⋆
I
(
k
+
i
)
/
∑
I
(
k
)
2
[
2
]
FIG. 5 shows a typical example of a normalized function G(τ) change as function of time and over systolic occlusion (20 sec occlusion vs 0.5 sec onset) as measured on the finger tip by DLS system 100 . For the purpose of the present application, the term “over systolic occlusion” refers to an application of over systolic pressure to create a temporary blood flow cessation state at the measurement location. The first measurement onset (T=0.5 sec) displays a more fast decrease of G(t) in initial measurement stage (0-0.001 sec) comparatively to second measurement (T=20 sec) occlusion data. More moderate time-dependent decrease of G(t) is noticed for both experiments in more advanced stage (>0.001 sec)
The logarithmic scale presentation of the same represented in FIG. 6 reveals a quasi-exponential nature of function G(τ).
According to the second approach, the power spectrum presentation is used to process the detected signal. The power spectrum of the measured signal can be constructed by using a standard Fast Fourier Transformation (FFT) digital signal processing algorithm. FIG. 7 shows an example of the FFT of such a signal. The highest spectral frequency in the FFT presentation is defined by the number of the sampling points and the overall measurement time interval. The total energy of a power spectrum PwS[f1,f2] is bounded in the frequencies interval (f1, f2) and can be evaluated by a simple summation. This value can be used as a measure of changes which occurs during any physiological processes during the blood flow or during the blood flow cessation.
FIG. 8 shows the time variation of the full integral of the power spectrum (i.e. energy power spectrum) during an 80 sec duration measurement section of the pulsatile signal. Each point of the power spectrum PwS[f1,f2] is calculated for a pre-set time interval. In this particular example, the interval is 0.0454 sec. The calculated value is normalized:
PwS
[
f
1
,
f
2
]
=
∑
f
1
f
2
PwS
(
f
)
/
∑
0
f
max
PwS
(
f
)
[
3
]
FIG. 9 shows the time variation of the full integral of the power spectrum during the first 10 seconds of the pulsatile signal. The characteristic behavior of the power spectrum PwS depends upon the frequency interval f1,f2. For example, referring to FIGS. 10 and 11 a - b , the function defined by PwS [0,550 Hz] (t) for the frequency window [0,550 Hz], behaves differently as compared to PwS [2700, 10000 Hz] ( FIG. 11 a - b ). Strong dependence of PwS function upon the chosen frequencies parameters is confirmed for the pulsatile phase, as illustrated in FIG. 11 a and FIG. 11 b . At a predetermined a frequency interval, PwS behaves as a very weak function of ongoing physiological scattering changes, as illustrated in FIG. 12 . In this particular example, this interval is identified as being located at approximately the frequency interval [1-1.6 kHz]. This interval is defined as the critical frequency point (CFP), which can be related to the parameters of the autocorrelation function.
According to the statements of the Wiener-Khinchin theorem, PwS density of a wide-sense-stationary random process is the Fourier Transform of the corresponding autocorrelation function. Since the autocorrelation function is an even function, the classic Fourier integral is reduced to:
P
(
ω
,
t
)
≈
∫
0
∞
〈
I
〉
2
2
⋆
π
cos
(
ω
⋆
τ
)
⋆
[
g
2
(
τ
,
t
)
-
1
]
⋆
ⅆ
τ
[
4
]
For a very simple case, the normalized intensity correlation function can be approximated to: g 2 (τ)≈exp(−α*τ), where α is a factor proportional to the diffusion parameter D.
After the integration of the expression, [4] reduces to:
P
≈
α
α
2
+
ω
2
[
5
]
In order to find the minimum point of P, the differentiation of g with respect to α is taken:
d
(
P
)
=
(
-
2
α
2
(
α
2
+
ω
2
)
2
+
1
α
2
+
ω
2
)
⋆
d
α
[
6
]
Therefore,
for P ( t )=0,ω=α [7]
According to this expression, CFP can be used to evaluate the diffusion parameter D.
The post-occlusion pulsatile sessions (80-86 sec) are represented for the frequency window [0, 2150 Hz] in FIG. 13 a , and for the frequency window [2700, 10000 Hz] in FIG. 13 b.
Thus, the invented technique provides for using DLS for measurement of various parameters of a subject, particularly blood analytes. In this connection, it should be noted that the multiple scattering predominates the light propagation through the blood and tissue. This is why the transport approximation is considered to be a more appropriate approach for the invented technique.
In the case of DLS, the measured parameter is autocorrelation function g 1 . For an infinite medium with a point source, this parameter can be approximated by:
g 1 (τ)=exp(−√{square root over ( k 0 2 *<Δr 2 (τ)>+3μ α l )}*( r sd /l ) [8]
where <r 2 (τ)>=6Dτ is the mean squared displacement of the scattered particles, l is mean free path of light and D is the diffusion coefficient given by Stoke-Einstein relation.
D = kT 3 ⋆ πη d [ 9 ]
Substitution of K and D into [8] gives:
g
1
(
τ
,
λ
)
=
exp
(
-
(
2
π
n
/
λ
)
2
⋆
kT
3
⋆
πη
d
+
3
μ
a
⋆
l
⋆
(
r
sd
/
l
)
[
10
]
It should be pointed out that μ α is a function of light absorption dependent on the hemoglobin concentration and blood oxygen saturation level in blood. This expression can be used to process the DLS measurement of aggregation driven post-occlusion measurement where the Brownian motion takes over.
The value g 1 relates to the measured autocorrelation function by the Segert relation:
g 2 (τ)=1+β*| g 1 | 2 [11]
In the case of a free pulsatile signal, the blood flow related phenomena are dominated by fluctuations of blood cells with a major contribution of red blood cells (RBC).
The autocorrelation function decay is governed by the velocity variations measured across the blood vessels. If V(L) is the standard deviation of velocity difference across the source width L, then decay time is defined by:
τ
c
≈
1
dV
(
L
)
[
12
]
The velocity difference of flowing blood is a function of its shear rate. This rate depends on variety of rheological parameters, such as blood viscosity or the actual size of flowing particles. Single RBC tends to form aggregates that can reversibly disaggregate under the influence of shear forces; RBC aggregation is a major determinant of the shear-thinning property of blood.
In a vessel of radius R, axisymmetric velocity profiles v(r,t) can be described in cylindrical coordinates by the empirical relationship:
v ( r,t )≈ v max *(1−( r/R ) ξ )* f ( t ) [13]
where −1<(r/R)<1,f(t) is a periodic function of heart beat frequency, which is driven by systolic pressure wave and it is time phase-shifted with respect to the cardiac cycle, and ξ represents the degree of blunting. For example, in 30 micron arterioles, there is a range of ξ2.4-4 at normal flow rates. If ξ=2, a parabolic velocity distribution is obtained. Blunting would occur even in larger arterioles at low flow rates. By using the expression for d(v(r,t)) the standard deviation d(v) can be calculated by:
rms
(
dV
)
=
v
max
⋆
f
(
t
)
∫
dv
(
r
)
⋆
r
2
⋆
ⅆ
r
∫
dv
(
r
)
⋆
ⅆ
r
=
ξ
⋆
R
2
2
+
ξ
⋆
v
max
⋆
f
(
t
)
[
14
]
For small arterials (around 20 microns), the fluctuation of velocity from systolic to diastolic phases ranges from 1.5 mm/s to 2.5 mm/s. This results in a very significant fluctuation of standard deviation (rms) during the systolic-diastolic cycle. Pulsatile signal, therefore, can be used for calculation of hemorheological parameters. The DLS related pulsatile signal is advantageous over regular pulse measurement where the motion artifacts are prevalent. In addition, it should be noted that hemorheological changes can be extracted optically even if the scattering or absorption related changes are negligible.
Therefore two major benefits are achieved: first, the pulsatile or other hemorheological change can be measured optically by using DLS-related technique; secondly, due to the process of only high frequency components in the DLS approach, low frequency interference is therefore eliminated, also eliminating motion artifacts.
Another hemorheological parameter relates to the blood plasma viscosity. The post-occlusion signal (which is achieved during the stasis stage) can be utilized to evaluate blood plasma viscosity. In this case, the particles are displaced in the blood by Brownian motion according to the Stoke-Einstein equation [9].
It is clear that for the post-occlusion signal, the observed changes in the DLS signal are driven by the growth rate of d(t), following the growth of RBC aggregate size. The rate of RBC aggregate growth can be defined by calculating the change of autocorrelation function occurring during the stage of blood flow cessation (post-occlusion stage). Therefore the rate of RBC aggregation can be measured by using this technique.
If the DLS signal is measured simultaneously at two or more wavelengths, then by using equation [10] or other such equations, the most influential scattering or absorption related parameters, such as oxygen blood saturation, hemoglobin or glucose can be determined since absorption properties of the scattering particles affect the DLS related parameters [10].
If the measurement system (e.g. system 100 ) includes a controllable pressurizing assembly, then the DLS effect can be used for measurement of arterial blood pressure. The point of systolic pressure is easily identified as a point of disappearance of the pulsatile signal, which is monitored either in terms of autocorrelation parameters or in terms of power spectrum. When the arterial pressure exceeds the cuff pressure, blood squirts through the partially occluded artery and creates turbulence, which creates the well-known Korotkoff sounds. Effect of turbulence results in dramatic change in fluctuation dependent speckle pattern which is expressed in an instant change of DLS parameters.
In many applications ln(G(τ)) can be approximated by a polynomial form:
G (τ)= A·τ 2 +B·τ+C [15]
FIG. 14 illustrates how the pulsatile and post occlusion signals can be presented in terms of polynomial coefficients A and B being defined in terms of autocorrelation analysis. In this example, the measurement session includes few physiological stages: a) an initial pulsatile signal session, b) an arterial blood occlusion session, and c) a pulsatile signal session after release of the over systolic (occlusion) session, all over the measurement duration of 80 seconds.
FIG. 15 shows the behavior of a DLS related parameter (d(ln(G)/dt)) utilized for the determination of systolic and diastolic blood pressure. In this experiment, the pressurizing cuff is inflated up to over systolic pressure of 200 mm Hg during the first 5 seconds. Thereafter, for the next 75 seconds, the air pressure in the cuff is gradually reduced. Simultaneously, the DLS measurement is carried out at the area beneath the cuff. It is clearly seen in FIG. 15 , that the parameter d(Ln(G))/dt reaches its minimum point when the pressure measured in the cuff gets equal to the systolic pressure, as was defined previously by doing a standard blood pressure measurement test. Moreover, at the moment where the pressure in the cuff exceeds previously defined systolic pressure point, exactly at this point the value of parameter d(Ln(G))/dt starts to increase gradually. Therefore, by identifying these two extreme points on the curve of d(Ln(G))/dt, both systolic and diastolic blood pressure can be measured optically. Naturally, all other functions mathematically related to autocorrelation parameters, can be used for blood pressure measurement.
This very unique sensitivity of DLS related parameters to the blood flow can be used for identification of blood flow disturbances or even for blood stasis identification and verification. To this end, any kind of a medical tool such as intro-vascular catheter (e.g. used for angioplasty) can be linked with DLS equipped optical fiber. Such a system is very efficient for identification of plugs and blood vessels abnormalities disturbing the normal blood flow.
Moreover, blood circulation parameters measured by DLS technique can by embedded as an inherent part of new emerging technology of biofeedback. Based upon the biofeedback technique, different body parameters including the blood flow that can be beneficial to control emotional status, cardiovascular training, rehabilitation and other purposes can be controlled. For example, such a system can be used for the control of blood flow during recovery from heart failure. In the biofeedback applications, DLS based measurement system can be combined with facilities affecting the mental status of a subject. For example, a method of binaural beats can be used. The binaural beats are resulted from the interaction of two different auditory impulses, originating in opposite ears. The binaural beat is not heard but is perceived as an auditory beat and theoretically can be used to entrain specific neural rhythms through the frequency-following response (FFR), i.e. the tendency for cortical potentials to entrain to or resonate at the frequency of an external stimulus. Thus, a consciousness management technique can be utilized to entrain a specific induction of sympathetic and parasympathetic system. More specifically, biofeedback system based on the methods of binaural beats can be governed by the parameters of flowing blood measured by means of DLS.
There is also provided a method to select appropriate frequencies characteristics of the binaural beats, according to the optimization curve of peripheral blood parameters, which are tightly associated with a stage of maximum relaxation.
EXAMPLES
Various examples were carried out to prove the embodiments claimed in the present invention. Some of these experiments are referred hereinafter. The examples describe the manner and process of the present invention and set forth the best mode contemplated by the inventors for carrying out the invention, but are not to be construed as limiting the invention.
Example 1
To develop an optimized experimental approach for noninvasive visualization of blood clotting in vivo, an experimental protocol which allows visualizing fine changes in RBC motion at high spatial and temporal resolution, deep inside the tissue was established.
The experiments were performed on occluded blood vessels and detection was carried out by modification of DLS described above. Anesthetized animal (nude mice) were placed on the stage of a setup for intravital microscopy. Temporal over systolic occlusion was created by using a mechanical occluder which produces local mechanical pressure on the area of visibly large arteries within the mouse ear. The duration of the occlusion did not exceed 10 minutes.
In the first set of experiments, the illuminated area was imaged via a microscope by a CCD camera. The exposure time T of the CCD was 50 ms. Images were acquired through easy-control software at 20 Hz. The optical design of the system allowed for simultaneous laser irradiation and observation of a process of blood clotting via usage of a short pass optical filter (450 nm) placed in front of the CCD camera.
It was observed that mechanical occlusion of major blood vessels never leads to complete blood flow stasis in microvessels. Even after maximal occlusion, RBCs continued to move and the character of such motions was not stochastic. RBCs were moving for up to 1 hour after animals were euthanatized. Therefore the absence of RBC motion in an occluded vessel can be a sign of blood clotting in vivo since polymerized fibrin can prevent even minimal movements of RBCs.
Example 2
In order to monitor the blood clotting process, as well as to solve the problem of light scattering by skin and tissue, DLS from laser light was used for imaging the fine changes in RBC motion inside occluded vessels through the skin of the mouse ear. Particularly in the second set of experiments, the same animal model and procedures for animal care as described above were used.
A diode laser (670 nm, 10 mW) was coupled with a diffuser, which was adjusted to illuminate the area of a mouse ear. The illuminated area was imaged through a zoom stereo microscope by a CCD camera. The exposure time T of the CCD was 50 ms. Images were acquired through easy-control software at 20 Hz. DLS imaging of RBC motion in occluded microvessels was based on the temporal contrast of intensity fluctuations produced from laser speckles that reflected from mouse tissue.
The temporal statistics of time integrated speckles was utilized in order to obtain a two-dimensional velocity map which represents blood vessels under flow and no-flow conditions. The value of the laser temporal contrast K t at pixel (x,y) was calculated based on the following formula:
K t ( x,y )=σ x,y / I x,y
Where I x,y (n) is the CCD counts at pixel (x,y) in the n th laser speckle image, N is the number of images acquired and I x,y is the mean value of CCD counts at pixel (x,y) over the N images.
Temporal mechanical blood occlusion in the observed area was applied, as described before, to ensure blood flow cessation. Referring to FIG. 16 , the laser temporal speckle contrast K t was higher (intensity scale 0-1 in the right side of the image refers the value of laser speckle temporal contrast) inside occluded blood vessels in which RBC motion can be detected. These vessels are represented by “white” pattern while the darker areas are referred to the blood vessels in which RBC motion was low or negligible.
In addition, two minutes after occlusion, the beam of a Diode Pumped Solid State (DPSS) laser module, (Laser-Glow, Canada, 532 nm, 100 mW) was directed (at an angle of 45 degrees or less) onto the ear of an anesthetized mouse. The laser was focused in order to create a pinpoint injury on the mouse ear (200 μm). The injury was induced with a short high intensity laser burst and laser injury was induced at the area indicated by white arrows in frames 15 s and 20 s . The “white” pattern of blood vessels during DLS imaging, as illustrated in FIG. 17 of occluded blood vessels in the mouse ear can be related to remaining RBC motion. Conversely, relative changes in the intensity of K t upon clotting can be caused by elevation of blood/plasma viscosity as a result of blood clotting.
In the experiments, two elements of Virchow's triad were used to induce the process of clotting in vivo and to assess it optically. Both changes in the vessel wall, as well as in the pattern of blood flow, predispose the area to vascular thrombosis and blood clotting. Thus, DLS images generated by RBC motion inside occluded blood vessels as a marker of the blood clotting process in vivo were used.
Example 3
In order to monitor the change of oxygen saturation, a DLS system having two light sources was used. The light sources have respectively a wavelength of 650 nm and 810 nm. Absorption at these wavelengths differs significantly between oxyhemoglobin and its deoxygenated form, therefore from the ratio of the absorption of the red and infrared light the oxy/deoxyhemoglobin ratio can be calculated. The ratio of the two autocorrelation parameter (R 1 , R 2 ) for each wavelength was measured. The patient was asked to hold hit breath for approximately 30 seconds. As illustrated in FIG. 18 , the oxygen saturation drops. Then, the breath was reactivated, illustrated by a restoration of the oxygen saturation. The graph demonstrates the behavior of ratio of R 1 /R 2 during this experiment and reveals good correspondence between the ratio and the induced change of oxygen saturation.
Example 4
By using the DLS related technique of the present invention, heart rate can also be measured. In this experiment, the method was tested on an upper wrist. This particular area is considered as a hardly available area for the commonly used photoplethysmographic method of pulse measurement. The pulsatile component in the wrist area is very weak and therefore is not used nor for heart rate measurement neither for pulse oximetry.
A special probe including a coherent light source (VCSEL (vertical cavity surface emitting laser) of 820 nm), a detection unit, a laser driver and a preamplifier probe was constructed. The detection unit was located in close vicinity of the light source. All this system was encapsulated in the enclosure having a wristwatch form. This “wristwatch” was closely attached to the wrist and the measurement has been carried out. The DLS signal reflected from the skin area has been detected, amplified and digitized at the rate of 40 KHz. The obtained results have been processed. The auto-correlation function (AUT) was determined and averaged over 0.05 sec and the slope of the logarithm of AUT as a function of τ (sampling rate) was calculated. (d(ln(AUT)/dτ)).
FIG. 19 represents the measured pulsatile component of the blood in terms of d(ln(AUT)/dτ. Heart rate is extracted from the obtained signal by utilizing any of commonly used methods such as FFT method.
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. | A system, method and medical tool are presented for use in non-invasive in vivo determination of at least one desired parameter or condition of a subject having a scattering medium in a target region. The measurement system comprises an illuminating system, a detection system, and a control system. The illumination system comprises at least one light source configured for generating partially or entirely coherent light to be applied to the target region to cause a light response signal from the illuminated region. The detection system comprises at least one light detection unit configured for detecting time-dependent fluctuations of the intensity of the light response and generating data indicative of a dynamic light scattering (DLS) measurement. The control system is configured and operable to receive and analyze the data indicative of the DLS measurement to determine the at least one desired parameter or condition, and generate output data indicative thereof. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of application Ser. No. 10/127,180, filed Apr. 22, 2002, now U.S. Pat. No. 6,846,811.
BACKGROUND OF THE INVENTION
This invention relates to vitamin D compounds, and more particularly to the pro-drugs (20S)-1α-hydroxy-2α-methyl and 2β-methyl-19-nor-vitamin D 3 and their pharmaceutical uses.
The natural hormone, 1α,25-dihydroxyvitamin D 3 and its analog in ergosterol series, i.e. 1α,25-dihydroxyvitamin D 2 are known to be highly potent regulators of calcium homeostasis in animals and humans, and their activity in cellular differentiation has also been established, Ostrem et al., Proc. Natl. Acad. Sci. USA, 84, 2610 (1987). Many structural analogs of these metabolites have been prepared and tested, including 1α-hydroxyvitamin D 3 , 1α-hydroxyvitamin D 2 , various side chain homologated vitamins and fluorinated analogs. Some of these compounds exhibit an interesting separation of activities in cell differentiation and calcium regulation. This difference in activity may be useful in the treatment of a variety of diseases as renal osteodystrophy, vitamin D-resistant rickets, osteoporosis, psoriasis, and certain malignancies.
Recently, a new class of vitamin D analogs has been discovered, i.e. the so called 19-nor-vitamin D compounds, which are characterized by the replacement of the A-ring exocyclic methylene group (carbon 19), typical of the vitamin D system, by two hydrogen atoms. Biological testing of such 19-nor-analogs (e.g., 1α,25-dihydroxy-19-nor-vitamin D 3 ) revealed a selective activity profile with high potency in inducing cellular differentiation, and very low calcium mobilizing activity. Thus, these compounds are potentially useful as therapeutic agents for the treatment of malignancies, or the treatment of various skin disorders. Two different methods of synthesis of such 19-nor-vitamin D analogs have been described (Perlman et al., Tetrahedron Lett. 31, 1823 (1990); Perlman et al., Tetrahedron Lett. 32, 7663 (1991), and DeLuca et al., U.S. Pat. No. 5,086,191).
In U.S. Pat. No. 4,666,634, 2β-hydroxy and alkoxy (e.g., ED-71) analogs of 1α,25-dihydroxyvitamin D 3 have been described and examined by Chugai group as potential drugs for osteoporosis and as antitumor agents. See also Okano et al., Biochem. Biophys. Res. Commun. 163, 1444 (1989). Other 2-substituted (with hydroxyalkyl, e.g., ED-120, and fluoroalkyl groups) A-ring analogs of 1α,25-dihydroxyvitamin D 3 have also been prepared and tested (Miyamoto et al., Chem. Pharm. Bull. 41, 1111 (1993); Nishii et al., Osteoporosis Int. Suppl. 1, 190 (1993); Posner et al., J. Org. Chem. 59, 7855 (1994), and J. Org. Chem. 60, 4617 (1995)).
Recently, 2-substituted analogs of 1α,25-dihydroxy-19-nor-vitamin D 3 have also been synthesized, i.e. compounds substituted at 2-position with hydroxy or alkoxy groups (DeLuca et al., U.S. Pat. No. 5,536,713), with 2-alkyl groups (DeLuca et al U.S. Pat. No. 5,945,410), and with 2-alkylidene groups (DeLuca et al U.S. Pat. No. 5,843,928), which exhibit interesting and selective activity profiles. All these studies indicate that binding sites in vitamin D receptors can accommodate different substituents at C-2 in the synthesized vitamin D analogs.
In a continuing effort to explore the 19-nor class of pharmacologically important vitamin D compounds, two analogs which are characterized by the presence of a methyl substituent at the carbon 2 (C-2) and the absence of a hydroxyl group at carbon 25 (C-25) in the side chain have been synthesized and tested. These two analogs are characterized by a hydroxyl group at carbon 1 and a vitamin D 3 side chain with the methyl group attached to carbon 20 in the unnatural or epi orientation, i.e. (20S)-1α-hydroxy-2α-methyl and 2β-methyl-19-nor-vitamin D 3 . These vitamin D analogs seemed interesting targets because the relatively small methyl group at C-2 should not interfere with the vitamin D receptor. Moreover, molecular mechanics studies seem to indicate that such molecular modification substantially alters the conformation of the cyclohexanediol ring A, shifting its conformational equilibrium toward the chair form with equatorially oriented methyl substituent at C-2.
SUMMARY OF THE INVENTION
The present invention is directed toward the pro-drugs (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 (formula Ia below) and (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 (formula Ib below), their biological activity, and various pharmaceutical uses for these compounds.
Structurally these 2α-methyl and 2β-methyl 19-nor analogs are characterized by formula Ia and Ib, respectively shown below:
The above two compounds exhibit a desired, and highly advantageous, pattern of biological activity. These compounds do not bind or bind poorly to the vitamin D receptor. However, the 2α-methyl compound has greater intestinal calcium transport activity, as compared to that of 1α,25-dihydroxyvitamin D 3 , and has greater ability to mobilize calcium from bone, as compared to 1α,25-dihydroxyvitamin D 3 . The 2β-methyl compound has intestinal calcium transport activity and bone calcium mobilization activity about the same as 1α,25-dihydroxyvitamin D 3 . Hence, these compounds can be characterized as having very potent calcemic activity, and are highly specific in their calcemic activity. Their activity on mobilizing calcium from bone and either high or normal intestinal calcium transport activity allows the in vivo administration of these compounds for the treatment of metabolic bone diseases where bone loss is a major concern. Because of their activity on bone, these compounds would be preferred therapeutic agents for the treatment of diseases where bone formation is desired, such as osteoporosis, especially low bone turnover osteoporosis, steroid induced osteoporosis, senile osteoporosis or postmenopausal osteoporosis, as well as osteomalacia.
The compounds of the invention have also been discovered to be especially suited for treatment and prophylaxis of human disorders which are characterized by an imbalance in the immune system, e.g. in autoimmune diseases, including multiple sclerosis, lupis, diabetes mellitus, host versus graft reaction, and rejection of organ transplants; and additionally for the treatment of inflammatory diseases, such as rheumatoid arthritis, asthma, and inflammatory bowel diseases such as celiac disease and Crohns disease. Acne, alopecia and hypertension are other conditions which may be treated with the compounds of the invention.
The above compounds are also characterized by high or significant cell differentiation activity. Thus, these compounds also provide a therapeutic agent for the treatment of psoriasis, or as an anti-cancer agent, especially against leukemia, colon cancer, breast cancer and prostate cancer. In addition, due to their relatively high cell differentiation activity, these compounds provide a therapeutic agent for the treatment of various skin conditions including wrinkles, lack of adequate dermal hydration, i.e. dry skin, lack of adequate skin firmness, i.e. slack skin, and insufficient sebum secretion. Use of these compounds thus not only results in moisturizing of skin but also improves the barrier function of skin.
The compounds may be present in a composition to treat the above-noted diseases and disorders in an amount from about 0.01 μg/gm to about 100 μg/gm of the composition, and may be administered topically, transdermally, orally or parenterally in dosages of from about 0.01 μg/day to about 100 μg/day.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph illustrating the relative activity of (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 , (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 , and 1α,25-dihydroxyvitamin D 3 to compete for binding of [ 3 H]-1,25-(OH) 2 -D 3 to the vitamin D pig intestinal nuclear receptor; and
FIG. 2 is a graph illustrating the percent HL-60 cell differentiation as a function of the concentration of (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 , (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 , and of 1α,25-dihydroxyvitamin D 3 .
DETAILED DESCRIPTION OF THE INVENTION
(20S)-1α-Hydroxy-2α-methyl-19-nor-vitamin D 3 and (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 were synthesized and tested. Structurally, these 19-nor analogs are characterized by the formula Ia and Ib, respectively, previously illustrated herein.
The preparation of (20S)-1α-hydroxy-2α-methyl- and (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 having structures Ia and Ib can be accomplished by a common general method, i.e. the condensation of a bicyclic Windaus-Grundmann type ketone II with the allylic phosphine oxide III to the corresponding 2-methylene-19-nor-vitamin D analog IV followed by deprotection of hydroxyls at C-1 and C-3 in the latter compound; and then followed by a selective reduction of the exomethylene group at C-2 in compound V to provide the 2α-methyl isomer (Ia) and 2β-methyl isomer (Ib):
In the structures III and IV groups Y 1 and Y 2 are hydroxy-protecting groups, preferably tBuMe 2 Si groups, it being also understood that any functionalities that might be sensitive, or that interfere with the condensation reaction, be suitably protected as is well-known in the art. The process shown above represents an application of the convergent synthesis concept, which has been applied effectively for the preparation of vitamin D compounds [e.g. Lythgoe et al., J. Chem. Soc. Perkin Trans. I, 590 (1978); Lythgoe, Chem. Soc. Rev. 9, 449 (1983); Toh et al., J. Org. Chem. 48, 1414 (1983); Baggiolini et al., J. Org. Chem. 51, 3098 (1986); Sardina et al., J. Org. Chem. 51, 1264 (1986); J. Org. Chem. 51, 1269 (1986); DeLuca et al., U.S. Pat. No. 5,086,191; DeLuca et al., U.S. Pat. No. 5,536,713].
A hydrindanone of the structure II is a new compound that can be prepared from commercial vitamin D 2 by modification of known methods. Thus, the starting alcohol 1 was prepared from commercial vitamin D 2 in 3 steps (Scheme 1). The resulting C-22 alcohol 1 was oxidized to the aldehyde 2, which then was equilibrated at C-20. The mixture of (20R)- and (20S)-aldehydes was reduced and (20R)-alcohol 3 was isolated by chromatography. This, in turn, was tosylated and the tosylate 4 coupled with the Grignard reagent 5 in the presence of dilithium tetrachlorocuprate. The obtained hydrindanol 6 was oxidized to the new (20S)-Grundmann ketone analog II.
For the preparation of the required phosphine oxides of general structure III, a new synthetic route has been developed starting from a methyl quinicate derivative which is easily obtained from commercial (1R,3R,4S,5R)-(−)-quinic acid as described by Perlman et al., Tetrahedron Lett. 32, 7663 (1991) and DeLuca et al., U.S. Pat. No. 5,086,191.
The final step of the process is the selective homogeneous catalytic hydrogenation of the exomethylene unit at carbon 2 in the vitamin V performed efficiently in the presence of tris(triphenylphosphine)rhodium(I) chloride [Wilkinson's catalyst, (Ph 3 P) 3 RhCl]. Such reduction conditions allowed to reduce only C(2)=CH 2 unit leaving C(5)–C(8) butadiene moiety unaffected. The isolated material is an epimeric mixture (ca. 1:1) of 2-methyl-19-nor-vitamins Ia and Ib differing in configuration at C-2. The mixture can be used without separation or, if desired, the individual 2α- and 2β-isomers can be separated by an efficient HPLC system.
The overall process of the synthesis of compounds Ia and Ib is illustrated and described more completely in U.S. Pat. No. 5,945,410 entitled “2-Alkyl-19-Nor-Vitamin D Compounds” the specification of which is specifically incorporated herein by reference.
Specifically, the preparation of hydrindanone II is described hereinafter and illustrated in Scheme I. The final steps of the convergent synthesis, i.e. the coupling of this compound with phosphine oxide 7 followed by hydroxyl deprotection in the vitamin D compound 8 and reduction/hydrogenation of the exomethylene unit in 2-methylene-19-nor-vitamin D compound V is also hereinafter described and illustrated in Scheme 2.
Preparation of (20S)-de-A,B-8β-benzoyloxy-20-(hydroxymethyl)pregnane (1)
The starting alcohol 1 was prepared from commercial vitamin D 2 in 70% yield, according to the procedure published by J. C. Hanekamp, R. B. Rookhuizen, H. J. T. Bos, L. Brandsma Tetrahedron, 1992, 48, 9283–9294.
Ozone was passed through a solution of vitamin D 2 (3 g, 7.6 nmol) in methanol (250 mL) and pyridine (2.44 g, 2.5 mL, 31 mmol) for 50 min at −78° C. The reaction mixture was then flushed with an oxygen for 15 min to remove the residual ozone and the solution was treated with NaBH 4 (0.75 g, 20 mmol). After 20 min the second portion of NaBH 4 (0.75 g, 20 mmol) was added and the mixture was allowed to warm to room temperature. The third portion of NaBH 4 (0.75 g, 20 mmol) was then added and the reaction mixture was stirred for 18 h. The reaction was quenched with water (40 mL) and the solution was concentrated under reduced pressure. The residue was extracted with ethyl acetate (3×80 mL) and the combined organic phase was washed with 1M aq. HCl, saturated aq. NaHCO 3 , dried (Na 2 SO 4 ) and concentrated under reduced pressure. The residue was chromatographed on silica gel with hexane/ethyl acetate (75:25) to give (20S)-de-A,B-20-(hydroxymethyl)pregnan-8β-ol (1.21 g, 75% yield) as white crystals.
Benzoyl chloride (2.4 g, 2 mL, 17 mmol) was added to a solution of the 8β,20-diol (1.2 g, 5.7 mmol) and DMAP (30 mg, 0.2 mmol) in anhydrous pyridine (20 mL) at 0° C. The reaction mixture was stirred at 4° C. for 24 h, diluted with methylene chloride (100 mL), washed with 5% aq. HCl, water, saturated aq. NaHCO 3 , dried (Na 2 SO 4 ) and concentrated under reduced pressure. The residue (3.39 g) was treated with solution of KOH (1 g, 15.5 mmol) in anhydrous ethanol (30 mL) at room temperature. After stirring of the reaction mixture for 3 h, ice and 5% aq. HCl were added until pH=6. The solution was extracted with ethyl acetate (3×50 mL) and the combined organic phase was washed with saturated aq. NaHCO 3 , dried (Na 2 SO 4 ) and concentrated under reduced pressure. The residue was chromatographed on silica gel with hexane/ethyl acetate (75:25) to give the alcohol 1 (1.67 g, 93% yield) as a colorless oil: [α] D +56.0 (c 0.48, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 +TMS) δ 8.08–8.02 (2H, m, o-H Bz ), 7.59–7.53 (1H, m, p-H Bz ), 7.50–7.40 (2H, m, m-H Bz ), 5.42 (1H, d, J=2.4 Hz, 8α-H), 3.65 (1H, dd, J=10.5, 3.2 Hz, 22-H), 3.39 (1H, dd, J=10.5, 6.8 Hz, 22-H), 1.08 (3H, d, J=5.3 Hz, 21-H 3 ), 1.07 (3H, s, 18-H 3 ); 13 C NMR (125 MHz) δ 166.70 (s, C═O), 132.93 (d, p-C Bz ), 131.04 (s, i-C Bz ), 129.75 (d, o-C Bz ), 128.57 (d, m-C Bz ), 72.27 (d, C-8), 67.95 (t, C-22), 52.96 (d), 51.60(d), 42.15 (s, C-13), 39.98 (t), 38.61 (d), 30.73 (t), 26.81 (t), 22.91 (t), 18.20 (t), 16 87 (q, C-21), 13.81 (q, C-18); MS (EI) m/z 316 (5, M + ), 301 (3, M + -Me), 299 (1, M + −OH), 298 (2, M + -H 2 O), 285 (10, M + −CH 2 OH), 257 (6), 230 (9), 194 (80), 135 (84), 105 (100); exact mass calculated for C 20 H 28 O 3 316.2038, found 316.2019.
Preparation of (20S)-de-A,B-8β-benzoyloxy-20-formylpregnane (2)
A mixture of alcohol 1 (1.63 g, 5.2 mmol), pyridinium dichromate (6.05 g, 16.1 mmol) and pyridinium p-toluenesulfonate (100 mg, 0.4 mmol) in anhydrous methylene chloride (30 mL) was stirred at room temperature for 12 h. The resulting suspension was filtered through a short layer of Celite. The adsorbent was washed with ether, solvents were removed under reduced pressure and a residue was purified by column chromatography on silica gel with hexane/ethyl acetate (90:10) to give the aldehyde 2 (1.36 g, 83% yield) as an oil: 1 H NMR (400 MHz, CDCl 3 +TMS) δ 9.60 (1H, d, J=3.1 Hz, CHO), 8.05 (2H, m, o-H Bz ), 7.57 (1H, m, p-H Bz ), 7.45 (2H, m, m-H Bz ), 5.44 (1H, s, 8α-H), 2.39 (1H, m, 20-H), 2.03 (2H, dm, J=11.5 Hz), 1.15 (3H, d, J=6.9 Hz, 21-H 3 ), 1.10 (3H, s, 18-H 3 ); MS (EI) m/z 314 (1, M + ), 299 (0.5, M + -Me), 286 (1, M + −CO), 285 (5, M + −CHO), 257 (1, M + -C 3 H 5 O), 209 (10, M + −PhCO), 192 (38), 134 (60), 105 (100), 77 (50); exact mass calculated for C 20 H 26 O 3 314.1882, found 314.1887.
Preparation of (20R)-de-A,B-8β-benzoyloxy-20-(hydroxymethyl)pregnane (3)
The aldehyde 2 (1.36 g, 4.3 mmol) was dissolved in CH 2 Cl 2 (15 mL) and a 40% aq. n-Bu 4 NOH solution (5.6 mL, 5.57 g, 8.6 mmol) was added. The resulting mixture was stirred at room temperature for 16 h, diluted with methylene chloride (30 mL), washed with water, dried (Na 2 SO 4 ) and concentrated under reduced pressure. A residue was chromatographed on silica gel with hexane/ethyl acetate (95:5) to afford a mixture of aldehyde 2 and its 20-epimer (730 mg, 53% yield) in ca. 1:1.7 ratio (by 1 H NMR).
This mixture of aldehydes (730 mg, 2.3 mmol) was dissolved in THF (5 mL) and NaBH 4 (175 mg, 4.6 mmol) was added, followed by a dropwise addition of ethanol 5 mL). The reaction mixture was stirred at room temperature for 30 min and it was quenched with a saturated aq. NH 4 Cl solution. The mixture was extracted with ether (3×30 mL) and the combined organic phase was washed with with water, dried (Na 2 SO 4 ) and concentrated under reduced pressure. The residue was chromatographed on silica gel with hexane/ethyl acetate (95:5→80:20) to give the desired, pure (20R)-alcohol 3 (366 mg, 52% yield) as an oil and a mixture of 3 and its 20-epimer 1 (325 mg, 45% yield) in ca. 1:4 ratio (by 1 H NMR).
3: [α] D +43.0 (c 0.54, CHCl 3 ); 1 H NMR (500 MHz, CDCl 3 +TMS) δ 8.10–8.00 (2H, m, o-H Bz ), 7.60–7.53 (1H, m, p-H Bz ), 7.48–7.41 (2H, m, m-H Bz ), 5.42 (1H, br s, 8α-H), 3.75 (1H, dd, J=10.6, 3.5 Hz, 22-H), 3.48 (1H, dd, J=10.6, 7.0 Hz, 22-H), 1.069 (3H, s, 18-H 3 ), 0.973 (3H, d, J=6.7 Hz, 21-H 3 ); 13 C NMR (125 MHz) δ 166.70 (s, C═O), 132.94 (d, p-C Bz ), 131.05 (s, i-C Bz ), 129.76 (d, o-C Bz ), 128.59 (d, m-C Bz ), 72.28 (di C-8), 66.95 (t, C-22), 52.94 (d), 51.77 (d), 41.96 (s, C-13), 39.56 (t), 37.78 (d), 30.75 (t), 26.67 (t), 22.71 (t), 18.25 (t), 16.76 (q, C-21), 14.14 (q, C-18); MS (EI) m/z 316 (16, M + ), 301 (5, M + −Me), 299 (2, M + −OH), 298 (3, M + -H 2 O), 285 (9, M + -CH 2 OH), 257 (5), 242 (11), 230 (8), 194 (60), 147 (71), 105 (100); exact mass calculated for C 20 H 28 O 3 316.2038, found 316.2050.
Preparation of (20R)-de-A,B-8-benzoyloxy-20-[(p-toluenesulfonyl)oxymethyl]pregnane (4)
To a stirred solution of the alcohol 3 (393 mg, 1.24 mmol), DMAP (10 mg, 0.08 mmol) and Et 3 N (0.7 mL, 0.51 g, 5.04 mmol) in anhydrous methylene chloride (10 mL) was added p-toluenesulfonyl chloride (320 mg, 1.68 mmol) at 0° C. The reaction mixture was allowed to warm to room temperature (4) and stirring was continued for additional 22 h. Methylene chloride (60 mL) was added and the mixture was washed with a saturated aq. NaHCO 3 solution, dried (Na 2 SO 4 ) and concentrated under reduced pressure. A residue was chromatographed on silica gel with hexane/ethyl acetate (95:5) to afford a tosylate 4 (533 mg, 91% yield) as a colorless oil: [α] D =+15.0 (c 0.54, CHCl 3 ); 1 H NMR (500 MHz, CDCl 3 +TMS) δ 8.02 (2H, m, o-H Bz ), 7.80 (2H, d, J=8.2 Hz, o-H Ts ), 7.55 (1H, m, p-H Bz ), 7.44 (2H, m, m-H Bz ), 7.35 (2H, d, J=8.2 Hz, m-H Ts ), 5.39 (1H, br s, 8α-H), 4.15 (1H, dd, J=9.4, 3.4 Hz, 22-H), 3.83 (1H, dd, J=9.4, 7.1 Hz, 22-H), 2.457 (3H, s, Me Ts ), 1.98 (1H, m), 0.978 (3H, s, 18-H 3 ), 0.898 (3H, d, J=6.6 Hz, 21H 3 ); 13 C NMR (125 MHz) δ 166.60 (s, C═O), 144.87 (s, p-C Ts ), 133.35 (s, i-C Ts ), 132.98 (d, p-C Bz ), 130.94 (s, i-C Bz ), 129.97 (d, m-C Ts ), 129.72 (d, o-C Bz ), 128.58 (d, m-C Bz ), 128.13 (d, o-C Ts ), 74.21 (t, C-22), 72.03 (d, C-8), 52.44 (d), 51.52 (d), 41.82 (s, C-13), 39.30 (t) 35.00 (d), 30.57 (t), 26.56 (t), 22.54 (t), 21.85 (q, Me Ts ), 18.12 (t), 16.85 (q, C-21), 14.09 (q, C-18); MS (EI) m/z 470 (1, M + ), 365 (33, M + −PhCO), 348 (64, M + −PhCOOH), 193 (52), 176 (71), 134 (72), 105 (100); exact mass calculated for C 27 H 34 O 5 S 470.2127, found 470.2091.
Preparation of (20S)-de-A,B-cholestan-8β-ol (6)
Magnesium turnings (1.32 g, 55 mmol), 1-chloro-3-methylbutane (3.3 mL, 2.9 g, 27.2 mmol) and iodine (2 crystals) were refluxed in anhydrous TRF (18 mL) for 10 h. The solution of the formed Grignard reagent 5 was cooled to −78° C. and added dropwise via cannula to a solution of the tosylate 4 (348 mg, 0.74 mmol) in anhydrous THF (5 mL) at −78° C. Then 6 mL of the solution of Li 2 CuCl 4 [prepared by dissolving of a dry LiCl (232 mg, 5.46 mmol) and dry CuCl 2 (368 mg, 2.75 mmol) in anhydrous THF (27 mL)] was added dropwise via cannula to the reaction mixture at −78° C. The cooling bath was removed and the mixture was stirred at room temperature for 20 h and then poured into 1M aq. H 2 SO 4 solution (25 mL) containing ice (ca. 100 g). The mixture was extracted with methylene chloride (3×50 mL) and the combined organic layers were washed with saturated aq. NH 4 Cl, saturated aq. NaHCO 3 , dried (Na 2 SO 4 ) and concentrated under reduced pressure. The residue was chromatographed on silica gel with chloroform to give alcohol 6 (149 mg, 76% yield) as a colorless oil: 1 H NMR (400 MHz, CDCl 3 +TMS) δ 4.07 (1H, d, J=2.2 Hz, 8α-H), 1.98 (1H, dm, J=13.1 Hz), 0.93 (3H, s, 18-H 3 ), 0.86 (6H, d, J=6.6 Hz, 26- and 27-H 3 ), 0.81 (3H, d, J=6.6 Hz, 21-H 3 ); 13 C NMR (125 MHz) δ 69.41 (d, C-8), 56.27 (d), 52.62 (d), 41.84 (s, °C-13), 40.28 (t), 39.38 (t), 35.40 (t), 34.83 (d), 33.51 (t), 28.03 (d), 27.10 (t), 23.93 (t), 22.72 (q, C-26/27), 22.63 (q, C-26/27), 22.40 (t), 18.53 (q, C-21), 17.47(t), 13.73 (q, C-18); MS (EI) m/z 266 (7, M + ), 251 (6, M + −Me), 248 (2, M + -H 2 O), 233 (4, M + −Me —H 2 O), 163 (6), 152 (11), 135 (38), 111(100); exact mass calculated for C 18 H 34 O 266.2610, found 266.2601.
Preparation of (20S)-de-A,B-cholestan-8-one (II)
Pyridinium dichromate (90 mg, 239 μmol) was added to a solution of the alcohol 6 (15 mg, 56 μmol) and pyridinium p-toluenesulfonate (2 mg, 8 μmol) in anhydrous methylene chloride (6 mL). The resulting suspension was stirred at room temperature for 3.5 h. The reaction mixture was filtered through a Waters silica Sep-Pak cartridge (2 g) that was further washed with CHCl 3 . After removal of solvents ketone II (13 mg, 88% yield) was obtained as a colorless oil: 1 H NMR (400 MHz, CDCl 3 +TMS) δ 2.46 (1H, dd, J=11.5, 7.6 Hz), 0.89 (6H, d, J=6.6 Hz, 26- and 27-H 3 ), 0.87 (3H, d, J=6.1 Hz, 21-H 3 ), 0.65 (3H, s, 18-H 3 ); MS (EI) m/z 264 (41, M + ), 249 (37, M + -Me), 246 (3, M + -H 2 O), 231 (3, M + -Me —H 2 O), 221 (50, M + -C 3 H 7 ), 152 (34), 125 (100), 111 (69); exact mass calculated for C 18 H 32 O 264.2453, found 264.2454.
Preparation of (20S)-1α-hydroxy-2-methylene-19-norvitamin D 3 (V)
To a solution of phosphine oxide 7 (34 mg, 58 μmol) in anhydrous THF (450 μL) at −20 C. was slowly added PhLi (1.7 M in cyclohexane-ether, 75 μL, 128 μmol) under argon with stirng. The solution turned deep orange. After 30 min the mixture was cooled to −78° C. and a precooled (−78° C.) solution of ketone II (12 mg, 45 μmol) in anhydrous THF (200+100 μL) was slowly added. The mixture was stirred under argon at −78° C. for 3 h and at 0° C. for 18 h. Ethyl acetate was added, and the organic phase was washed with brine, dried (Na 2 SO 4 ) and evaporated. The residue was dissolved in hexane and applied on a Waters silica Sep-Pak cartridge (2 g). The cartridge was washed with hexane and hexane/ethyl acetate (99.5:0.5) to give 19-norvitamin derivative 8 (12 mg). The Sep-Pak was then washed with hexane/ethyl acetate (96:4) to recover the unchanged C,D-ring ketone II (7 mg), and with ethyl acetate to recover diphenylphosphine oxide 7 (19 mg). The protected vitamin 8 was further purified by HPLC (10×250 mm Zorbax-Silica column, 4 mL/min) using hexane/2-propanol (99.9:0.1) solvent system. Pure compound 8 (10 mg, 36% yield) was eluted at R V =15 mL as a colorless oil: UV (in hexane) λ max 262.5, 252.5, 243.5 nm; 1 H NMR (500 MHz, CDCl 3 ) δ 6.21 and 5.82 (1H and 1H, each d, J=11.1 Hz, 6- and 7-H), 4.95 and 4.90 (1H and 1H, each s, ═CH 2 ), 4.41 (2H, m, 1β-and 3α-H), 2.80 (1H, dd, J=11.9, 3.5 Hz, 9β-H), 2.49 (1H, dd, J=13.2, 6.0 Hz, 10α-H), 2.44 (1H, dd, J=12.7, 4.6 Hz, 4α-H), 2.32 (1H, dd, J=13.2, 3.1 Hz, 10β-H), 2.16 (1H, dd, J=12.7, 8.2 Hz, 4β-H), 1.98 (2H, m), 1.84 (1H, m), 0.876 (9H, s, Si-t-Bu), 0.851 (6H, d, J=6.0 Hz, 26- and 27-H 3 ), 0.845 (9H, s, Si-t-Bu), 0.820 (3H, d, J=6.5 Hz, 21-H 3 ) 0.521 (3H, s, 18-H 3 ), 0.060, 0.046, 0.029 and 0.006 (each 3H, each s, 4×Si—CH 3 ); MS (EI) m/z 628 (3, M + ), 613 (1, M + -Me), 571 (3, M + -t-Bu), 496 (63, M + -t-BuMe 2 SiOH), 383 (4, M + -t-BuMe 2 SiOH−C 8 H 17 ), 366 (21), 234 (20), 129 (41), 75 (100); exact mass calculated for C 39 H 72 O 2 Si 2 628.5071, found 628.5068.
Protected vitamin 8 (10 mg, 16 μmol) was dissolved in anhydrous THF (3 mL) and a solution of tetrabutylammonium fluoride (1 M in THF, 160 μL, 160 μmol) was added, followed by freshly activated molecular sieves 4A (300 mg). The mixture was stirred under argon at room temperature for 2 h, then diluted with 2 mL of hexane/ethyl acetate (6:4) and applied on a Waters silica Sep-Pak cartridge (2 g). Elution with the same solvent system gave the crude product V that was further purified by HPLC (10×250 mm Zorbax-Silica column, 4 mL/min) using hexane/2-propanol (9:1) solvent system. Analytically pure 2-methylene-19-norvitamin V (3.3 mg, 52% yield) was collected at R V =32 mL as a colorless oil: UV (in EtOH) λ max 261.5, 251.5, 243.5 nm; 1 H NMR (500 MHz, CDCl 3 +TMS) δ 6.36 and 5.88 (1H and 1H, each d, J=11.3 Hz, 6- and 7-H), 5.11 and 5.09 (each 1H, each s, ═CH 2 ), 4.47 (2H, m, 1β- and 3α-H), 2.85 (1H, dd, J=13.4, 4.6 Hz, 10β-H), 2.81 (1H, br d, J=13.9 Hz, 9β-H), 2.58 (1H, dd, J=13.2, 3.7 Hz, 4α-H), 2.33 (1H, dd, J=13.2, 6.1 Hz, 4β-H), 2.29 (1H, dd, J=13.4, 8.4 Hz, 10α-H), 1.99 (2H, m), 1.86 (1H, m), 0.867 (6H, d, J=6.6 Hz, 26- and 27-H 3 ), 0.839 (3H, d, J=6.5 Hz, 21-H 3 ), 0.547 (3H, s, 18-H 3 ); MS (EI) m/z 400 (100, M + ), 385 (5, M + −Me), 382 (16, M + -H 2 O), 367 (6, M + -Me —H 2 O), 349 (3, M + -Me-2H 2 O), 315 (46), 287 (56, M + -C 8 H 17 ), 269 (52), 247 (42); exact mass calculated for C 27 H 44 O 2 400.3341, found 400.3346.
Preparation of (20S)-1α-hydroxy-2α-methyl-19-norvitamin D 3 (Ia) and (20S)-1α-hydroxy-2β-methyl-19-norvitamin D 3 (Ib)
Tris(triphenylphosphine)rhodium (I) chloride (3.5 mg, 3.8 μmol) was added to dry benzene (2.5 mL) presaturated with hydrogen. The mixture was stirred at room temperature until a homogeneous solution was formed (ca. 45 min). A solution of vitamin V (1.8 mg, 4.5 μmol) in dry benzene (400+400 μL) was then added and the reaction was allowed to proceed under a continuous stream of hydrogen for 3 h. Benzene was removed under vacuum, the residue was redissolved in hexane/ethyl acetate (1:1) and applied on a Waters silica Sep-Pak cartridge (2 g). A mixture of 2-methyl vitamins was eluted with the same solvent system. The compounds were further purified by HPLC (10×250 mm Zorbax-Silica column, 4 mL/min) using hexane/2-propanol (9:1) solvent system. The mixture of 2-methyl-19-norvitamins Ia and Ib gave a single peak at R V 34 mL. Separation of both epimers was achieved by reversed-phase HPLC (10×250 mm Chromegabond C18 column, 3 mL/min) using methanol/water (9:1) solvent system. 2β-Methyl vitamin Ib (280 μg, 15% yield) was collected at R V =47 mL and its 2α-epimer Ia (382 μg, 21% yield) at R V =51 mL.
Ia: UV (in EtOH) λ max 260.5, 250.5, 242.5 nm; 1 H NMR (500 MHz, CDCl 3 +TMS) δ 6.37 and 5.82 (1H and 1H, each d, J=11.1 Hz, 6- and 7-H), 3.96 (1H, m, w/2=14 Hz, 1β-H), 3.61 (1H, m, w/2=20 Hz, 3, α-H), 2.80 (2H, br m, 9β- and 10α-H), 2.60 (1H, dd, J=13.0, 4.5 Hz, 4α-H), 2.22 (1H, br d, J=12.8 Hz, 10β-H), 2.13 (1H,˜t, J=13.0 Hz, 4β-H), 1.133 (3H, d, J=6.8 Hz, 2α-CH 3 ), 0.866 (6H, d, J=6.6 Hz, 26- and 27-H 3 ), 0.833 (3H, d, J=6.4 Hz, 21-H 3 ), 0.530 (3H, s, 18-H 3 ); MS (EI) m/z 402 (100, M + ), 387 (4, M + -Me), 384 (7, M + -H 2 O), 369 (3, M + -Me —H 2 O), 317 (24), 289 (60, M + -C 8 H 17 ), 271 (33), 259 (40), 247 (63); exact mass calculated for C 27 H 46 O 2 402.3498, found 402.3496.
Ib: UV (in EtOH) λ max 260.5, 250.0, 242.0 nm; 1 H NMR (500 MHz, CDCl 3 +TMS) δ 6.26 and 5.87 (1H and 1H, each d, J=11.3 Hz, 6-H and 7-H), 3.90 (1H, m, w/ 2=14 Hz, 3α-H), 3.50 (1H, m, w/2=26 Hz, 1β-H), 3.08 (1H, dd, J=12.6, 4.3 Hz, 10β-H), 2.80 (1H, dd, J=12.5, 3.8 Hz, 9β-H), 2.43 (1H, br d, J=ca. 14 Hz, 4α-H), 2.34 (1H, dd, J=13.9, 3.0 Hz, 4β-H), 1.143 (3H, d, J=6.8 Hz, 2β—CH 3 ) 0.867 (6H, d, J=6.6 Hz, 26- and 27-H 3 ), 0.839 (3H, d, J=6.5 Hz, 21-H 3 ), 0.543 (3H, s, 18-H 3 ); MS (EI) m/z 402 (100, M + ), 387 (8, M + -Me), 384 (8, M + -H 2 O), 369 (5, M + -Me —H 2 O), 317 (42), 289 (88, M + -C 8 H 17 ), 271 (52), 259 (55), 247 (66); exact mass calculated for C 27 H 46 O 2 402.3498, found 402.3486.
Biological Activity of (20S)-1α-Hydroxy-2α-Methyl and 2β-Methyl-19-Nor-Vitamin D 3
The 2β-methyl-(20S)-1α-hydroxyvitamin D 3 does not bind to the vitamin D receptor, while the 2α-methyl-(20S)-1α-hydroxyvitamin D 3 binds the receptor but at a 100-fold less affinity than 1α,25-dihydroxyvitamin D 3 (1,25-(OH) 2 D 3 ) ( FIG. 1 ). The absence of a 25-hydroxyl group in these compounds is largely responsible (see Eisman, J. A. and H. F. DeLuca, Steroids 30, 245–257,1977) for this diminished activity. Importantly, the 2α-methyl derivative is superior to the 2β-methyl analog in binding to the receptor.
Surprisingly, FIG. 2 illustrates (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 is almost as potent as 1,25-(OH) 2 D 3 on HL-60 differentiation, making it an excellent candidate for the treatment of psoriasis and cancer, especially against leukemia, colon cancer, breast cancer and prostate cancer. In addition, due to its relatively high cell differentiation activity, this compound provides a therapeutic agent for the treatment of various skin conditions including wrinkles, lack of adequate dermal hydration, i.e. dry skin, lack of adequate skin firmness, i.e. slack skin, and insufficient sebum secretion. Use of this compound thus not only results in moisturizing of skin but also improves the barrier function of skin. The 2β derivative is 100 times-less active than 1,25(OH) 2 D 3 making it less effective in these areas.
The data in Table 1 show that (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 has high activity relative to that of 1,25-(OH) 2 D 3 , the natural hormone, in stimulating intestinal calcium transport. Also, (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 has significant activity in stimulating intestinal calcium transport, and its activity is about the same as 1,25-(OH) 2 D 3 .
The data in Table 1 also demonstrate that (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 has higher bone calcium mobilization activity, as compared to 1,25-(OH) 2 D 3 . Also, (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 has significant bone calcium mobilization activity, and its activity is about the same as 1,25-(OH) 2 D 3 .
A very important feature of these analogs is that they bind poorly or not at all to the vitamin D receptor, while having biological activity either higher than or equal to 1,25-(OH) 2 D 3 . This suggests that these analogs are pro drugs. That is, they are probably activated in vivo by being 25-hydroxylated. Once 25-hydroxylated, they are then able to bind the vitamin D receptor and provide activity. These results suggest that these compounds might be preferable to the final drug in that they are slowly activated within the body providing a more controlled and prolonged activity.
The data in Table 1 thus illustrate that (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 may be characterized as having significant and very potent calcemic activity which is greater than 1,25-(OH) 2 D 3 , and that (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 also has significant and very potent calcemic activity that is about the same as 1,25-(OH) 2 D 3 .
Competitive binding of the analogs to the porcine intestinal receptor was carried out by the method described by Dame et al. (Biochemistry 25, 4523–4534,1986).
The differentation of HL-60 promyelocytic into monoctyes was determined as described by Ostrem et al. (J. Boil. Chem. 262, 14164–14171, 1987).
Intestinal calcium transport was determined as described by Perlman et al. (Biochemistry 29, 190–196, 1990).
INTERPRETATION OF DATA
The in vivo tests to determine serum calcium of rats on a low calcium diet provides an insight to osteoblastic or bone activity of (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 and (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 . The data in Table 1 show that (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 is significantly more potent than 1,25(OH) 2 D 3 in raising calcium in the plasma via the stimulation of the osteoblasts. At the same time, the activity of (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 on intestinal calcium transport is also significantly greater than that of 1,25-(OH) 2 D 3 (Table 1). Therefore, these data show (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 to have significant and very potent activity on bone which is higher than 1,25(OH) 2 D 3 .
The data in Table 1 also show that (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 is only slightly less potent than 1,25(OH) 2 D 3 in raising calcium in the plasma calcium via the stimulation of the osteoblasts. At the same time, the activity of (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 on intestinal calcium transport is about the same as that of 1,25-(OH) 2 D 3 (Table 1). Therefore, these data show (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 to have significant and very potent activity on bone about equal to 1,25(OH) 2 D 3 .
The compounds Ia and Ib exhibit a desired, and highly advantageous, pattern of biological activity. These compounds are characterized by relatively high intestinal calcium transport activity, as compared to that of 1α,25-dihydroxyvitamin D 3 , while also exhibiting relatively high activity, as compared to 1α,25-dihydroxyvitamin D 3 , in their ability to mobilize calcium from bone. Hence, these compounds are highly specific in their calcemic activity. Their activity on mobilizing calcium from bone and either high or normal intestinal calcium transport activity allows the in vivo administration of these compounds for the treatment of metabolic bone diseases where bone loss is a major concern. Because of their calcemic activity on bone, these compounds would be preferred therapeutic agents for the treatment of diseases where bone formation is desired, such as osteoporosis, especially low bone turnover osteoporosis, steroid induced osteoporosis, senile osteoporosis or postmenopausal osteoporosis, as well as osteomalacia.
(20S)-1α-Hydroxy-2α-methyl-19-nor-vitamin D 3 and (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 are much less active than 1,25(OH) 2 D 3 in binding to the vitamin D receptor ( FIG. 1 ), and they are both also only slightly less active than 1,25-(OH) 2 D 3 in causing differentiation of the promyelocyte, HL-60, into the monocyte ( FIG. 2 ). This result suggests that both (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 and (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 will be very effective in psoriasis because they have direct cellular activity in causing cell differentiation and in suppressing cell growth. It also indicates that they both will have significant activity as an anti-cancer agent, especially against leukemia, colon cancer, breast cancer and prostate cancer, as well as against skin conditions such as dry skin (lack of dermal hydration), undue skin slackness (insufficient skin firmness), insufficient sebum secretion and wrinkles. These results also illustrate that (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 and (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 are both excellent candidates for numerous human therapies and that they may be useful in a number of circumstances in addition to cancer and psoriasis such as autoimmune diseases.
Male, weanling Sprague-Dawley rats were placed on Diet 11 (0.47% Ca) diet+AEK for 11 days, followed by Diet 11 (0.02% Ca)+AEK for 31 days. Dosing (i.p.) began 7 days prior to sacrifice. Doses were given on a daily basis, 24 hours apart. The first 10 cm of the intestine was collected for gut transport studies and serum was collected for bone Ca mobilization analysis. The results are reported in Table 1.
TABLE 1
Response of Intestinal Calcium Transport and Serum Calcium
(Bone Calcium Mobilization) Activity to Chronic Doses of
1,25-(OH) 2 D 3 and (20S)-1α-Hydroxy-
2α-methyl-19-nor-vitamin D 3 and (20S)-1α-Hydroxy-
2β-methyl-19-nor-vitamin D 3
Amount
Ca transport S/M
Serum Ca
Compound
(pmol/day)
(mean ± SEM)
(mean ± SEM)
none (control)
0
4.5 ± 0.40
4.4 ± 0.07
1α,25-(OH) 2 D 3
130
5.3 ± 0.42
5.0 ± 0.05
260
6.5 ± 0.84
5.5 ± 0.16
(20S)-1α-(OH)-2α-
130
8.6 ± 0.90
10.0 ± 0.20
methyl-19-nor-D 3
260
6.7 ± 0.68
12.7 ± 0.15
(20S)-1α-(OH)-2β-
130
6.8 ± 0.73
4.8 ± 0.04
methyl-19-nor-D 3
260
5.7 ± 0.45
5.1 ± 0.04
*The above data are the average and standard error (SE) from 5 animals.
For treatment purposes, the compounds of this invention defined by formula Ia and Ib may be formulated for pharmaceutical applications as a solution in innocuous solvents, or as an emulsion, suspension or dispersion in suitable solvents or carriers, or as pills, tablets or capsules, together with solid carriers, according to conventional methods known in the art. Any such formulations may also contain other pharmaceutically-acceptable and non-toxic excipients such as stabilizers, anti-oxidants, binders, coloring agents or emulsifying or taste-modifying agents.
The compounds may be administered orally, topically, parenterally or transdermally. The compounds are advantageously administered by injection or by intravenous infusion or suitable sterile solutions, or in the form of liquid or solid doses via the alimentary canal, or in the form of creams, ointments, patches, or similar vehicles suitable for transdermal applications. Doses of from 0.01 μg to 100 μg per day of the compounds are appropriate for treatment purposes, such doses being adjusted according to the disease to be treated, its severity and the response of the subject as is well understood in the art. Since the compounds exhibit specificity of action, each may be suitably administered alone, or together with graded doses of another active vitamin D compound—e.g. 1α-hydroxyvitamin D 2 or D 3 , or 1α,25-dihydroxyvitamin D 3 —in situations where different degrees of bone mineral mobilization and calcium transport stimulation is found to be advantageous.
Compositions for use in the above-mentioned treatments comprise an effective amount of the (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 or (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 as defined by the above formula Ia and Ib as the active ingredient, and a suitable carrier. An effective amount of such compound for use in accordance with this invention is from about 0.01 μg to about 100 μg per gm of composition, and may be administered topically, transdermally, orally or parenterally in dosages of from about 0.01 μg/day to about 100 μg/day.
The compounds may be formulated as creams, lotions, ointments, topical patches, pills, capsules or tablets, or in liquid form as solutions, emulsions, dispersions, or suspensions in pharmaceutically innocuous and acceptable solvent or oils, and such preparations may contain in addition other pharmaceutically innocuous or beneficial components, such as stabilizers, antioxidants, emulsifiers, coloring agents, binders or taste-modifying agents.
The compounds are advantageously administered in amounts sufficient to effect the differentiation of promyelocytes to normal macrophages. Dosages as described above are suitable, it being understood that the amounts given are to be adjusted in accordance with the severity of the disease, and the condition and response of the subject as is well understood in the art.
The formulations of the present invention comprise an active ingredient in association with a pharmaceutically acceptable carrier therefore and optionally other therapeutic ingredients. The carrier must be “acceptable” in the sense of being compatible with the other ingredients of the formulations and not deleterious to the recipient thereof.
Formulations of the present invention suitable for oral administration may be in the form of discrete units as capsules, sachets, tablets or lozenges, each containing a predetermined amount of the active ingredient; in the form of a powder or granules; in the form of a solution or a suspension in an aqueous liquid or non-aqueous liquid; or in the form of an oil-in-water emulsion or a water-in-oil emulsion.
Formulations for rectal administration may be in the form of a suppository incorporating the active ingredient and carrier such as cocoa butter, or in the form of an enema.
Formulations suitable for parenteral administration conveniently comprise a sterile oily or aqueous preparation of the active ingredient which is preferably isotonic with the blood of the recipient.
Formulations suitable for topical administration include liquid or semi-liquid preparations such as liniments, lotions, applicants, oil-in-water or water-in-oil emulsions such as creams, ointments or pastes; or solutions or suspensions such as drops; or as sprays.
For asthma treatment, inhalation of powder, self-propelling or spray formulations, dispensed with a spray can, a nebulizer or an atomizer can be used. The formulations, when dispensed, preferably have a particle size in the range of 10 to 100μ.
The formulations may conveniently be presented in dosage unit form and may be prepared by any of the methods well known in the art of pharmacy. By the term “dosage unit” is meant a unitary, i.e. a single dose which is capable of being administered to a patient as a physically and chemically stable unit dose comprising either the active ingredient as such or a mixture of it with solid or liquid pharmaceutical diluents or carriers. | This invention discloses (20S)-1α-hydroxy-2α-methyl-19-nor-vitamin D 3 and (20S)-1α-hydroxy-2β-methyl-19-nor-vitamin D 3 and pharmaceutical uses therefor. These compounds exhibit pronounced activity in arresting the proliferation of undifferentiated cells and inducing their differentiation to the monocyte thus evidencing use as an anti-cancer agent and for the treatment of skin diseases such as psoriasis as well as skin conditions such as wrinkles, slack skin, dry skin and insufficient sebum secretion. These compounds also have very significant calcemic activity and therefore may be used to treat immune disorders in humans as well as metabolic bone diseases such as osteoporosis. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 60/912,068 filed on Apr. 16, 2007, which is incorporated by reference as if fully set forth.
FIELD OF INVENTION
[0002] The present invention is related to wireless communication systems. More particularly, the present invention is related to methods of optimizing the transmission of multiple public land mobile network identifiers (PLMN-ID)s by compressing one or more PLMN-ID components.
BACKGROUND
[0003] The third generation partnership project (3GPP) has initiated the Long Term Evolution (LTE) program to bring new technology, new network architecture, new configuration and new applications and services to the wireless cellular network in order to provide improved spectral efficiency and faster user experiences. As part of that program, LTE system information on the evolved-Universal Mobile Telecommunications Service (UMTS) Terrestrial Radio Access Network (E-UTRAN) should also support the network sharing feature by publishing multiple Public Land Mobile Network-Identifiers (PLMN-IDs) on the broadcast channels (BCH) on each of the LTE cells, and therefore on the primary-BCH (P-BCH) or dynamic-BCH, often enough so that a wireless transmit/receive unit (WTRU) can receive the PLMN-IDs in time to decide which PLMN it should access.
[0004] A PLMN-ID consists of a mobile country code (MCC) component and a mobile network code (MNC) component. A MCC may range numerically from 0 to 999. Therefore, a 10-bit field is required to represent (store) this 3-digit number. A MNC may also range from 0 to 999. It could be a 2 or 3-digit number. To facilitate network sharing in LTE, as well as other types of networks such as UMTS, a list of PLMN-IDs should be broadcasted to all of the wireless WTRUs in a cell.
[0005] UMTS Release-6 and 3GPP Work Group 2 proposals specify that multiple PLMN-IDs should be transmitted in the system information broadcast in the Master Information Block or the Broadcast Channel (BCH). In UMTS the MCC is marked OPTIONAL. If the PLMN-ID's MCC is the same as a previous PLMN-ID's MCC, then the MCC is not repeated in the message. Consequently, the present/not-present indicator takes one-bit in the formatted message, as shown in Table 1.
[0000]
TABLE 1
Prior Art for multiple PLMN-ID List formatting
MCC field value
MCC field length
Comment
MCC1
10-bit
MCC2
Presence bit (P-bit) exist in
Abstract Syntax Notation.One
(ASN.1) form, if 1,
field length = 10,
if 0, MCC2 == MCC1, MCC-2
is not sent, and field length = 0
MCC3
10-bit
Same as above
;;;
10-bit
;;
MCCn
10-bit
;;
[0006] In LTE, P-BCH bandwidth is very limited. Sending up to a maximum of 6 PLMN-IDs in a system block on the P-BCH is considered very expensive. Therefore, it would be desirable to optimize the use of bandwidth for efficient transmission of multiple PLMN-IDs.
SUMMARY
[0007] This application is related to a method and apparatus for optimizing the transmission of PLMN-IDs in a wireless network. This is accomplished by reducing the amount of bandwidth required to transmit a given set of PLMN-IDs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings wherein:
[0009] FIG. 1 is a flow chart of a method for optimizing PLMN-ID field lengths; and
[0010] FIG. 2A-2B is a flow chart of an alternative method of optimizing PLMN-ID field lengths using deltas.
[0011] FIG. 3 shows one example of an implementation of an embodiment in a WTRU.
[0012] FIG. 4 illustrates an embodiment in wireless network with different WTRUs (mobile device and an evolved Node B).
DETAILED DESCRIPTION
[0013] When referred to hereafter, the terminology “wireless transmit/receive unit (WTRU)” includes but is not limited to a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a personal digital assistant (PDA), a computer, a base station, or any other type of device capable of operating in a wireless environment. When referred to hereafter, the terminology “base station” includes but is not limited to a Node-B, an evolved Node-B, a site controller, an access point (AP), or any other type of interfacing device capable of operating in a wireless environment. When referred to hereafter, the terminology “format” is used interchangeably with the word “store.” When referred to hereafter, the terminology “data” refers to any type of information including but not limited to PLMN-IDs, PLMN-ID components, MNCs, MCCs, numbers, numerical identifiers, numerical values, symbols, symbolic values, etc. Throughout this application, the use of following notation: MCC-n and MCC n , are equivalent and interchangeable.
[0014] A MCC may have a value ranging from 0 to 999. Therefore, the minimum field length required to represent (store) a given MCC is 10-bits. However, not every MCC needs a full 10-bit field to convey its value. For example, a MCC of 111 may be stored in a 7-bit field. By using ┌Log 2 MCC┐ (a ceiling function for rounding up to the next smallest integer, e.g.: 3.23 to 4), the field length required to store a MCC may be reduced to less than 10 bits. Moreover, this technique does not require a field length indicator to be sent to a receiver (WTRU, mobile phone, etc.). A receiver, may predict the actual field length by using the following property: if a≧b≧0 then log 2 a≧log 2 b.
[0015] Since log 2 a≧log 2 b, multiple PLMN-IDs can be sorted into descending order, such that MCC-a is greater than or equal to MCC-b, and so on. When the first PLMN-ID is transmitted, it will contain MCC-a and the MCC-a component of the PLMN-ID will use the largest possible MCC field length (10-bits) and each subsequent PLMN-ID is transmitted containing a different MCC (say MCC-b) using a field length derived from the previous MCC value, ┌Log 2 MCC-a┐-bit field length. Therefore, each of the subsequent MCCs will use a field length derived from the previous MCC that is always less than or equal to the conventional 10-bit fixed field length. As previously noted, this solution also eliminates the need for a separate length indicator when transmitting PLMN-IDs. Thus, the field length of a given PLMN-ID (other than the first PLMN-ID with largest MCC) is reduced, and the aggregate field length and the time required for the transmission of PLMN-IDs is reduced.
[0016] FIG. 1 displays an example of a method in accordance with one embodiment. At step 110 , all PLMN-IDs are sorted based upon their respective MCC into descending numerical order, such that MCC-1>=MCC-2>=. . . >=MCC-n and so on, into a list (e.g.: a table or equivalent structure). This results in a list of PLMN-IDs [MCC-1, . . . MCC-n], where n is less than or equal to six (6) (the value six (6) is based upon existing standards, however, this embodiment works equally well with any value of n), with MCC-1 having the greatest MCC value. At step 120 , the MCC field of the first PLMN-ID (the one containing MCC-1) is formatted (stored) into a 10-bit field. Next, the rest of the PLMN-ID (the MNC) is stored into a corresponding fixed field (since the MNC can be a 2 or 3 digit number, the length of the MNC field will be 7-bits or 10-bits and may also require an additional one or two bit length indicator). At step 130 , the MCC field of the next PLMN-ID (the one containing MCC-2) is stored into a field of length ┌Log 2 MCC-1┐ if Log 2 MCC-1 is not an integer, otherwise the MCC field of the next PLMN-ID (MCC-2) is stored into a field of length ┌Log 2 MCC-1┐+1. Then the corresponding MNC (the rest of the PLMN-ID) is stored into its fixed field. Next, the MCC field of the next PLMN-ID (the one containing MCC-3) is stored into a field of length ┌Log 2 MCC-2┐ if Log 2 MCC-2 is not an integer, otherwise the MCC field of the next PLMN-ID (the one containing MCC-3) is stored into a field of length ┌Log 2 MCC-2┐+1, then the corresponding MNC is stored into its fixed field and so on until the end of the list is reached at step 140 . In general, the MCC field of PLMN-ID-n (the one containing MCC-n) is formatted (stored) into a field of length ┌Log 2 MCC-(n−1)┐ if Log 2 MCC-(n−1) is not an integer, otherwise the MCC field of PLMN-ID-n (the one containing MCC-n) is stored into a field of length ┌Log 2 MCC-(n−1)┐+1. In every case, the full field length of a PLMN-ID will be the sum of the following:
[0017] 1 bit (for the p-bit);
[0018] ┌Log 2 MCC-(n−1)┐ bits if Log 2 MCC-(n−1) is not an integer, or otherwise ┌Log 2 MCC-(n−1)┐+1 bits; and
[0019] the field length, in bits, of the MNC field.
[0000] TABLE 2 Implicit MCC Field Length Reduction illustration (without MNC or p-bit) MCC field value MCC field length Comment MCC-1 10-bit Greatest MCC value MCC-2 ┌Log 2 MCC-1┐ if Presence bit (P-bit) Log 2 MCC-1 ≠ integer, else still exist ┌Log 2 MCC-1┐+1 MCC-3 ┌Log 2 MCC-2┐ if Presence bit (P-bit) Log 2 MCC-2≠ integer, else still exist ┌Log 2 MCC-2┐+1 ; ; ; Presence bit (P-bit) still exist MCC-n ┌Log 2 MCC-(n−1)┐ if Presence bit (P-bit) Log 2 MCC-(n−1)≠ integer, still exist else ┌Log 2 MCC-(n−1)┐+1
After this processing completes the list is transmitted to one or a plurality of mobile devices (WTRU, mobile phone, etc.). In general, for MCC-2, the field length saving is (10−┌Log 2 MCC-1┐), for MCC-3 the field length saving is (10−┌Log 2 MCC-2┐) and for MCC-n the field length saving is (10−┌Log 2 MCC-(n−1)┐). The combined savings achieved by this optimization method can be expressed as
[0000]
[
(
N
-
1
)
×
10
-
∑
m
=
1
n
-
1
Log
2
MCC
m
)
]
.
[0000] Therefore, if the individual MCC values in the multiple PLMN-ID list are numerically small, that is, less than or equal to 255 (7-bits), then this method is very efficient.
[0020] Referring now to FIG. 2 , if the individual values of MCCs in the multiple PLMN-ID List are in the high value range, that is, greater than or equal to 256, while the value differences between them are relatively small (less than or equal to 63), another embodiment shown in FIG. 2 may be used. This embodiment results in a delta/offset field length that will be smaller than the typical field length required to store a MCC value in a PLMN-ID transmission.
[0021] The method 200 begins at step 205 in FIG. 2A , where given a list of PLMN-IDs, the method sets MCC-1 to the MCC value of the PLMN-ID in the list containing the largest MCC (the one with the greatest numerical value). If more than one greatest MCC exists, the one with the largest MNC is chosen. At step 210 , the rest of the PLMN-IDs are sorted in ascending order based upon their respective MCC value such that MCC-2≦MCC-3≦ . . . ≦MCC-n (if any PLMN-IDs have MCCs that are equal, then they are placed in the list in ascending order based upon their respective MNC value). At step 215 , the value differences or deltas δ MCC-1,m (m=2, . . . , n) between MCC-1 and each of the other MCCs (e.g.: δ MCC-1,2 =MCC-1−MCC-2) are calculated and at step 220 , each result is stored into a delta-list (e.g.: a table or equivalent structure) in descending order, such that, δ MCC-1,2 >=δ MCC-1,3 >=, . . . , δ MCC-1,n , where n=2, 3, . . . , N (where N≦6 in LTE). In particular if there are deltas (δ MCC-1,m ) equal to 0, which means that some MCCs are equal to MCC-1, then the zero-delta(s) are placed in the front of the delta-list, such that δ MCC-1,2 =0, δ MCC-1,3 >=δ MCC-1,4 >=, . . . , δ MCC-1,n ; this condition only occurs if one or more sequential delta values, beginning with the second delta value, are zero (one or more MCCs are equal to MCC-1).
[0022] At step 225 , the multiple PLMN-IDs are arranged starting with MCC-1 and the rest according to their order in the delta-list, such that [MCC-1, MCC-2 . . . MCC-n], where n is <=6 (typically, n=5 or 6 in LTE or WCDMA respectively, however, this embodiment will work with any value for n) and that MCC-2=MCC-1−δ MCC-1,2 , MCC-3=MCC-1δ MCC-1,3 , and so on. The aranging procedure may use a new list. In general, MCC-n=MCC-1−δ MCC-1,n ; utilizing this relationship, a receiver is able to derive the MCC values from the transmitted MCC-1 and the transmitted deltas.
[0023] At step 230 , the MCC-1 is formatted (stored) into a 10-bit field and the rest of the PLMN-ID (the MNC component) is stored in a corresponding additional field (the total field length will be 10 bits+the length required to store the MNC component). The p-bit is not in the MCC-1 entry.
[0024] At steps 240 and 244 , any zero-delta, for example, δ MCC-1,2 , MCCs are formatted by setting the presence-bit to 0 (no MCC or delta values are stored in the field (i.e.: a field length=0)), if any zero-delta-MCCs exist, the rest of the PLMN-ID (the MNC component) is stored in a corresponding additional field (thus the total field length for a PLMN-ID in this case is the length required to store the MNC component +1 (for the p-bit));
[0025] At step 242 , the first non-zero delta, say δ MCC-1,3 is formatted into a ┌Log 2 MCC-1┐ length field, if (Log 2 MCC-1) is not an integer, otherwise the first non-zero delta is formatted into a ┌Log 2 MCC-1┐+1 length field, the presence bit (p-bit) is set to 1 and the rest of the PLMN-ID (the MNC component) is stored in a corresponding additional field (the total field length will be ┌Log 2 MCC-1┐ bits if (Log 2 MCC-1) is not an integer, otherwise the total field length will be ΠLog 2 MCC-1┐+1 bits, + the length required to store the MNC component +1 bit (for the p-bit));
[0026] Continuing in FIG. 2B at step 260 , subsequent deltas are formatted (until the end of the list is reached) such that:
[0027] At step 250 , if the δ MCC-1,n equals the previous delta δ MCC-1,(n−1) , at 252 , the presence bit is set to 0, a delta value is not stored (no bits are used to store the delta value, e.g. a 0-bit field length) and the rest of the PLMN-ID (the MNC component) is stored in a corresponding additional field (the total field length in this case is the length required to store the MNC component +1 bit (for the p-bit));
[0028] At step 254 , if the δ MCC-1,n differs from the previous delta δ MCC-1,(n−1) , the presence bit is set to 1, the delta value δ MCC-1,n is stored into a field of length ┌Log 2 δ MCC-1,n−1┐ if ( Log 2 δ MCC-1,(n−) ) is not an integer, otherwise the delta value is stored into a field of length ┌Log 2 δ MCC-1,n− ┐+1 and the rest of the PLMN-ID (the MNC component) is stored in a corresponding additional field (the total field length will be ┌Log 2 ≡ MCC-1,n−1 ┐ bits if (Log 2 δ MCC-1,(n−1) ) is not an integer, otherwise the total field length will be ┌Log 2 δ MCC-1,n−1 ┐+1 bits, + the length required to store the MNC component +1 bit (for the p-bit)). At step 270 , after the entire list has been processed, the PLMN-IDs are transmitted to one or plurality of mobile devices (WTRUs, mobile phones or other mobile devices, etc.).
[0029] Table 3 displays an example of the multiple PLMN-ID list (without the MNC component) when no zero-deltas exist between any MCCs and the MCC-1.
[0000]
TABLE 3
Offset Field Reduction format with no zero-deltas
(without p-bit or MNC)
Field value
Field length
Comment
MCC-1
10-bit
Greatest MCC value (No p-bit is
needed for the first entry)
δ MCC-1, 2
┌Log 2 MCC-1┐ if
Presence bit (p-bit) exists and set
Log 2 MCC-1≠ integer,
(= 1).
else ┌Log 2 MCC-1┐ +1
If p-bit set, then MCC-2 =
MCC-1 − δ MCC-1, 2 ;
δ MCC-1, 3
┌Log 2 δ MCC - 1,2 ┐if
P-bit = 1; MCC-3 = MCC-1 −
Log 2 δ MCC-1, 2 ≠ integer,
δ MCC-1, 3 ;
else ┌Log 2 δ MCC - 1,2 ┐+1
; ; ;
P-bit = 1; MCC-3 = MCC-1 −
δ MCC-1, 3 ;
δ MCC-1, n
┌Log 2 δ MCC - 1,n − 1 ┐ if
MCC-n = MCC-1 − δ MCC-1, n
Log 2 δ MCC-1,(n−1) ≠
integer, else
┌Log 2 δ MCC - 1,n − 1 ┐+1
[0030] The following is an example of multiple PLMN-ID (without the MNC component) list compression when a zero-delta exists between MCC-2 and MCC-1. The virtual representative of MCC-2 (i.e. the P-bit=0, see Table 4) is inserted between the MCC-1 and the MCC with the largest delta to MCC-1 (note the usage of the presence bit P-bit in the example). The p-bit rule for this method is as follows: if the p-bit right after MCC-1 is not set, then MCC-2==MCC-1, and so on, until the first p-bit is set. The field length is now ┌Log 2 MCC-1┐ if Log 2 MCC-1 is not an integer, otherwise the field length is ┌Log 2 MCC-1┐+1, plus the p-bit. Store δ MCC-1,n into a field of length ┌Log 2 δ MCC-1,n−1 ┐ if (Log 2 δ MCC-1,(n−1) ) is not an integer, otherwise store δ MCC-1,n into a field of length ┌Log 2 δ MCC-1,n−1 ┐+1, plus the p-bit.
[0000]
TABLE 4
Offset Field Reduction format with zero-deltas (without MNC or p-bit)
[0031] In Table 4, row 4 demonstrates that when the P-bit=0, MCC-3 and MCC-4 have the same MCC value and therefore the same delta value with respect to MCC-1. An example would be MCC-1=866, MCC-2=866, MCC-3=502, MCC-4=502. So with respect to MCC-1, the δ MCC-1,2 =0, the δ MCC-1,3 =364, the δ MCC-1,4 =364. So both deltas are equal to 384 (not zero). But the two deltas (364 vs. 364) are equal, so we can take advantage of this fact to further reduce multiple (with equal MCCs) PLMN-ID transmission by setting the p-bit=0. This instructs the mobile device (WTRU, mobile phone, etc.) to use the previous delta value, in deriving the MCC for this particular delta value, as shown in Table 5, row 4, below (in actual transmission, only Presence-bit is transmitted to the mobile device; the field length equal to zero (0) is derived by the rules previously set forth above):
[0000]
TABLE 5
[0032] Given that certain methods, as set forth above, are applicable to particular combinations of PLMN-IDs and that the PLMN-IDs for network sharing in LTE are not often changed, the E-UTRAN may pre-test the PLMN-IDs using different compression methods, as set forth above, and publish the PLMN-IDs in the most efficient method appropriate to the given PLMN-IDs combinations. The E-UTRAN could announce the compression method (using a method indicator) in the system information block (SIB) broadcast together with the compressed multiple PLMN-IDs, so that the WTRUs in the cell know how to decode the network sharing PLMN-IDs.
[0033] Given that a MCC is unique, and given that there are less than 256 countries represented in the MCC lists, many values in the 3-digit MCC value range are not used. Therefore the MCC 3-digit value may be remapped into a new-MCC-entry-list of 256 or less, for example, 128, world-wide. Further, if that list can be divided by continent, then for each continent-MCC-entry-list, less that 128 values can be used.
[0000]
TABLE 5
Remap the MCC value to an Entry List
Entry-
Original MCC
Index
Value
Comment
0
MCC value 127
1
MCC value 135
2
MCC value 354
3
MCC value 788
;;
127
MCC value ???
[0034] The MCC values may be remapped to an Entry-List. In the multiple PLMN-ID list transmission, only the relevant Entry-Indexes may be used.
[0035] The same principles as described above equally apply to the MNC component of the PLMN-ID, i.e. the MNC may be similarly remapped into another entry-list and only the relevant MNC entry-index will be used in conjunction with the MCC entry-index for the transmission of multiple PLMN-IDs.
[0036] The aforementioned remapping methods may also be used in conjunction with the field length reduction techniques described above.
[0037] The aforementioned methods may be implemented in a variety of hardware devices. One implementation is in a an evolved Node-B (eNB) 300 shown in FIG. 3 . The eNB 300 contains a compressor 310 and a transmitter 320 . The eNB 300 obtains a list (typically from the network or a component of the network) of PLMN-IDs. The PLMN-IDs are passed to the compressor 310 which compresses one or both of the components of the PLMN-ID (MCC and MNC) according to the aforementioned techniques. The compressor 310 contains a processor 312 , a sorter 314 , a formatter 316 and an arranger 318 . The processor 312 performs a variety of calculations and manipulation of PLMN-ID components and data. The sorter 314 sorts PLMN-ID components and data in ascending or descending order. The formatter 316 stores PLMN-ID components and data, into lists, tables, and any other data structure. These lists, tables, and any other data structures may reside in volatile memory, nonvolatile memory or any other type of storage device. The arranger 318 is configured to arrange PLMN-ID components and data, moving such information around within and among the previously described data structures (or within a new data structure).
[0038] FIG. 4 illustrates an example of a wireless network 400 made up of WTRUs 420 , 430 , 440 , 450 and an evolved Node B (eNB) 460 with the eNB's coverage area 410 being illustrated. WTRUs generally include various components such as a transmitter component 420 T , a receiver component 420 R , a processor component 420 P and a memory component 420 M which are illustrated with respect to WTRU 420 . In this example, eNB 460 processes the PLMN-ID list according to the aforementioned methods and transmits a message containing an indication of the compression method and the compressed PLMN-ID list to any MD that requires the list such as MD 420 . MD 420 receives the message containing the compression method indicator and compressed PLMN-ID list in its receiver 420 R and then the MD 420 processor 420 P stores the compressed PLMN-ID list into its memory 420 M and uses the compression indicator to “decode” the compression list.
[0039] Although the features and elements of the present invention are described in the preferred embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the preferred embodiments or in various combinations with or without other features and elements of the present invention. The methods or flow charts provided in the present invention may be implemented in a computer program, software, or firmware tangibly embodied in a computer-readable storage medium for execution by a general purpose computer or a processor. Examples of computer-readable storage mediums include a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs).
[0040] Suitable processors include, by way of example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), and/or a state machine.
[0041] A processor in association with software may be used to implement a radio frequency transceiver for use in a wireless transmit receive unit (WTRU), user equipment (UE), terminal, base station, radio network controller (RNC), or any host computer. The WTRU may be used in conjunction with modules, implemented in hardware and/or software, such as a camera, a video camera module, a videophone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, a Bluetooth® module, a frequency modulated (FM) radio unit, a liquid crystal display (LCD) display unit, an organic light-emitting diode (OLED) display unit, a digital music player, a media player, a video game player module, an Internet browser, and/or any wireless local area network (WLAN) module. | This application is related to a method and apparatus for optimizing the transmission of PLMN-IDs in a wireless network. This is accomplished by reducing the amount of bandwidth required to transmit a given set of PLMN-IDs. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority, under 35 U.S.C. §119, of German Patent Application DE 10 2012 000 918.6, filed Jan. 18, 2012; the prior application is herewith incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a method for feeding sheets to a printing technology or graphic arts industry machine, which includes conveying the sheets onto a feed table in shingled formation using a first drive, conveying the sheets individually and successively from the feed table to a first processing station of the machine using a second drive and accelerating the drives starting from a base speed to a production speed.
[0004] German Patent DE 44 07 631 C1, corresponding to U.S. Pat. No. 5,584,244, discloses a method for bringing a sheet-fed printing press up to production speed. In accordance with the disclosed method, waste sheets are avoided during the acceleration by ensuring that sheets are separated from a stack and conveyed to a feed table only when a production run speed has been reached. That is done to ensure that no sheets are being printed while the sheet-fed printing press is accelerated to the production run speed. Due to the fact that the separating operation is switched on with a time delay, a relatively long period of time elapses between the moment the start-up of the printing press begins and the printing of the first sheet. The first separated sheet is conveyed onto the feed table at a high speed. That may cause thin sheets, in particular, to flutter at the corners, which may cause disruptions to the sheet-feeding operation.
[0005] In accordance with a method for bringing a printing technology machine up to production speed as disclosed in German Patent DE 196 39 134 C2, corresponding to U.S. Pat. No. 5,870,957, the amount of start-up waste is reduced in that the feeding of sheets is switched on prior to or during the acceleration of a sheet-fed printing press up to the production run speed. The switching-on instant is selected in such a way as to ensure that a first sheet does not reach a predetermined position in the machine until the production run speed has been reached. If the sheet-fed printing press is to be accelerated to a high production run speed, the instant at which the feeding of sheets is switched on is later than the beginning of the start-up operation. The first sheet that is conveyed onto a feed table has a relatively high speed. Again, there is a risk that the corners may flutter and that the feeding operation may be disrupted.
SUMMARY OF THE INVENTION
[0006] It is accordingly an object of the invention to provide a method for feeding sheets to a printing technology machine, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known methods of this general type and which improves reliability of a sheet-feeding operation and shortens a period of time required to accelerate the machine from a base speed to a production speed.
[0007] With the foregoing and other objects in view there is provided, in accordance with the invention, a method for feeding sheets to a printing technology machine. The method comprises conveying the sheets in a conveying direction onto a feed table in shingled formation using a first drive, conveying the sheets individually and successively from the feed table to a first processing station of the machine using a second drive, and accelerating the drives from a base speed to a production speed as follows: conveying the sheets to the feed table before the second drive has reached the production speed, stopping the first drive as soon as the sheets on the feed table assume a predefined position in the conveying direction and are at a predefined distance from each other, and then accelerating the first drive to the production speed after the processing station has reached the production speed.
[0008] In accordance with the invention, during the acceleration of a machine to a production speed, sheets are conveyed onto a feed table in shingled or overlapping, formation preferably at a speed that is lower than the current start-up speed. It is only when a first processing station of the machine has reached production speed that the drive for loading the feed table is accelerated to its production speed. Due to separate drives for the processing stations of the machine and for a conveying device on a feed table for a first processing station, it is possible to shingle the sheets at a low speed. The corners of the thin sheets are no longer in danger of starting to flutter. When the shingling operation on the feed table is completed, the processing operation does not start until the production speed of the machine is reached. The speed at which the sheets are conveyed onto the feed table may be adjusted as a function of the thickness of the sheets. The drive for the shingling of the sheets may temporarily be stopped when the sheets are in a predefined position on the feed table in the conveying direction and are at a predefined distance from each other.
[0009] The invention may be used in all printing technology machines in which sheets are fed in shingled formation. The invention is usable to particular advantage in sheet-fed printing presses, folders, die-cutters, folder-gluers, finishing machines and sheet inspection devices.
[0010] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0011] although the invention is illustrated and described herein as embodied in a method for feeding sheets to a printing technology machine, 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.
[0012] 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 SEVERAL VIEWS OF THE DRAWING
[0013] FIG. 1 is a fragmentary, diagrammatic, longitudinal-sectional view of a sheet-fed printing press having a main drive motor for printing units and a clutch for driving a feeder;
[0014] FIG. 2 is a longitudinal-sectional view of a sheet-fed printing press including a separate drive for a feeder and a main drive motor for the printing units;
[0015] FIG. 3 is a speed/time diagram for a first variant of the invention;
[0016] FIG. 4 is a speed/time diagram for a second variant of the invention; and
[0017] FIG. 5 is a speed/time diagram for a third variant of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] In known sheet-fed printing presses, one drive train is provided for the separation and conveying of sheets in a feeder and a separate drive train is provided for the conveying of the sheets through printing units. Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a diagrammatic representation of a sheet-fed printing press, in which a feeder 1 and two printing units 2 , 3 are shown. A stack 5 of sheets 4 is provided in the feeder 1 . A suction head 40 separates the sheets 4 from the top side of the stack 5 and conveys them to a feed table 6 . Among other elements, a conveying belt 8 guided by deflection rollers 9 , 10 is provided to advance the sheets 4 against front lays 7 . The sheets 4 are made available on the feed table 6 in shingled or overlapping formation before the printing operation starts.
[0019] During the printing operation, a swinging gripper 11 successively transfers individual sheets from the front lays 7 to grippers 12 of a feed drum 13 . The feed drum 13 subsequently transfers the sheets 4 to grippers 14 to 19 of an impression cylinder 20 , of a transfer drum 21 , and of an impression cylinder 22 . A respective color separation is printed onto the sheets 4 in a respective printing nip formed between a blanket cylinder 23 , 24 and an impression cylinder 20 , 22 . Each color separation is created by inking a printing form on a plate cylinder 25 , 26 . The plate cylinders 25 , 26 are in rolling contact with the blanket cylinders 23 , 24 and with inking form rollers of an inking unit 27 , 28 .
[0020] A main drive motor 29 that applies a torque to a transmission 30 is provided to drive the printing press. The transmission 30 is formed of a plurality of transmission components such as a belt drive and gears. Double lines 31 in the illustration indicate a transmission of torque or power between the transmission components and between the rollers 9 , 10 , drums 13 , 21 and cylinders 20 , 22 to 26 that are connected to the transmission components. The rollers 9 , 10 , drums 13 , 26 and cylinders 20 , 22 to 26 revolve in synchronism in the direction indicated by the arrows 32 .
[0021] A transmission 33 that is connectible to a drive train of the printing units 2 , 3 through the use of a clutch 34 is used to drive the sheet-conveying elements in the feeder 1 . Among other functions, the transmission 33 drives the suction head 40 and the conveying belt 8 .
[0022] The motor 29 and the clutch 34 are connected to a control device 35 . The axis of the feed drum 13 is connected to a rotary encoder 36 having a signal output which is connected to the control device 35 . Signals at the output of the rotary encoder 36 indicate a circumferential speed of the feed drum 13 and/or a current printing speed v of the sheet-fed printing press.
[0023] A first variant of the method may be carried out on the sheet-fed printing press described above as follows:
[0024] Before the production run of a print job is started or to restart the sheet-fed printing press after an interruption of the printing operation, the sheets 4 are conveyed onto the feed table 6 in shingled formation. When the clutch 34 is open, the drums 13 , 21 and cylinders 20 , 22 that convey the sheets 4 rotate at an idling speed v 1 of 3000 rpm (revolutions per minute of the feed drum 13 ), for example. If, as shown in FIG. 3 , a command to start up the sheet-fed printing press is issued at a time t 1 , the speed v is increased until a start-up speed v 2 , for example 5000 rpm, is reached at a time t 2 . A curve 37 illustrates the speed progression of the sheets as they are conveyed through the printing units 2 , 3 . A dashed curve 38 illustrates the speed progression of the sheets 4 for elements of the feeder 1 . At a time t 3 , the clutch is actuated so that the transmission 33 causes sheets 4 to be conveyed onto the feed table. Due to the rigid coupling between the transmissions 30 , 33 , the speed for the loading of the feed table 6 follows the speed progression of the drums 13 , 21 and cylinders 20 , 22 that convey the sheets 4 . At a time t 4 , the acceleration of the printing units 2 , 3 starts at a linear speed change. When the first sheet 4 rests against the front lays 7 at a time t 5 , the feed table 6 is fully loaded, so that the clutch 34 is disengaged and the feeder 1 stops conveying sheets. The maximum speed v 3 during the loading of the feed table is low enough for the first sheet to arrive at the front lays 7 without fluttering corners.
[0025] Subsequently, with the feeder 1 at a standstill, the sheet-fed printing press is accelerated to a production speed v 4 . After the drum 13 , 21 and the cylinders 20 , 22 rotate at production speed v 4 at a time t 6 and after a waiting period t W1 =t 5 −t 4 has passed, the clutch 34 is actuated to restart the feeder 1 . From the time t 6 on, individual sheets 4 are successively removed from the front lays 7 by the swinging grippers 11 and are fed to the first printing unit 2 . For this purpose, a pawl on the swinging gripper 11 is closed. When the pawl is open, the swinging gripper 11 is prevented from transporting a sheet. The sheets are transported in the feeder 1 at the same speed v 4 as in the printing units 2 , 3 .
[0026] In the following description, reference numerals or symbols that have already been introduced indicate elements with equivalent functions or symbolic content.
[0027] FIG. 4 illustrates a second variant of the method. The difference between the variant shown in FIG. 4 and the variant shown in FIG. 3 is that in the one shown in FIG. 4 , the waiting time t W2 or rather standstill time t W2 of the feeder 1 after the feed table 6 has been fully loaded is shortened. The clutch 34 is actuated at a time t 7 and an intermediate speed v 5 <v 4 . From the time t 7 on, sheets 4 are fed to the first printing unit 2 . While the speed is increased from the intermediate speed v 5 to production speed v 4 , sheets 4 are already being printed. The normal production run starts at a time t 6 .
[0028] In accordance with a variant shown in FIG. 2 , the sheet-fed printing press is equipped with a separate drive motor 39 for the feeder 1 . Thus, there is no mechanical driving connection between the transmissions 30 , 33 . Like the motor 29 , the motor 39 is controlled by the control device 35 . As a result of this driving configuration, the printing units 2 , 3 and the feeder 1 may be run independently of each other at different speed profiles. This is shown in more detail in FIG. 5 . While the drums 13 , 21 and cylinders 20 , 22 are accelerated form the start-up speed v 2 to production speed v 4 , the feed table 6 is loaded. For this purpose, the motor 39 is actuated at a time t 8 to initiate the loading of the feed table 6 at speed v 6 . This speed v 6 is higher than the respective current speed v 7 or v 8 of the drums 13 , 21 and cylinders 20 , 22 at times t 8 and t 9 , respectively. When the first sheet 4 has reached the front lays 7 , the loading of the feed table 6 is stopped at a time t 9 . A waiting time t W3 =t 6 −t 9 passes until the conveying of sheets in the feeder 1 is restarted. From the time t 6 on, the conveying of sheets in the feeder 1 and in the printing units 2 , 3 are in synchronism and sheets 4 are being printed in the production run.
[0029] The speed at which sheets 4 are conveyed onto the feed table 6 may be adjusted as a function of the properties of the sheets. For instance, the speed may be set as a function of the thickness, stiffness, surface roughness, or friction coefficient of the sheets. For example, the speed at which thin sheets 4 are conveyed onto the feed table 6 may be lower than the speed at which thick sheets 4 are conveyed. If the drives for the feeder 1 and for the printing units 2 , 3 are separately controllable, it is possible to convey sheets 4 of delicate paper onto the feed table 6 at a speed that is lower than the current start-up speed. | A method for feeding sheets to a printing technology machine improves reliability of feeding sheets and reduces an acceleration time from a base speed to a production speed. The sheets are conveyed onto a feed table in shingled formation by a first drive and are individually and successively conveyed from the feed table to a first processing station of the machine by a second drive. The sheets are conveyed onto the feed table before an acceleration of the second drive to production speed is completed and the first drive is accelerated to the production speed when the processing station has reached the production speed. | 1 |
RELATED APPLICATIONS
This application is a divisional of currently pending U.S. patent application Ser. No. 11/413,737 filed Apr. 28, 2006; now U.S. Pat. No. 7,312,965 which is a divisional application of Ser. No. 10/967,482, filed Oct. 18, 2004, U.S. Pat. No. 7,064,941, issued Jun. 20, 2006; which is a continuation of Ser. No. 10/892,051, filed Jul. 15, 2004 (Abandoned); which is a continuation of Ser. No. 10/611,218, filed Jul. 1, 2003, now U.S. Pat. No. 6,788,505, issued Sep. 7, 2004; which is a divisional of Ser. No. 09/954,474, filed Sep. 14, 2001, U.S. Pat. No. 6,618,229, issued Sep. 9, 2003; which is a continuation in part of Ser. No. 09/775,337, filed Feb. 1, 2001, now U.S. Pat. No. 6,583,975, issued Jun. 24, 2003.
BACKGROUND OF THE INVENTION
This invention relates generally to electrical control systems, and more specifically to an aircraft electrical control system which disconnects power to a load when a current imbalance is sensed.
In the electro-mechanical arts, current imbalances are indicative of serious problems that can lead to disastrous results, such as arcing within fuel pumps. Since fuel pumps are often housed within a fuel vessel to directly pump fuel out of the vessel, arcing within a fuel pump can lead to an explosion of fuel-air mixture and a subsequent breach of the fuel vessel, which can be catastrophic. In light of the seriousness of such an event, a device or methodology is needed which can suppress this type of arcing, as well as other associated problems. Presently, a common type of circuit protection device being utilized in aircraft is a thermal circuit breaker. However, arcing typically does not cause thermal circuit breakers to activate. Thus, there has been a long-felt need for the function of current imbalance detection in an aircraft. One very important form of current imbalance is a ground fault in which current is flowing between a circuit or electrical device to ground, when such current flow is not desired. In the prior art, ground fault detection has been addressed by a separate ground fault interruption unit. However, such prior art systems have had limitations, including the necessity of rewiring the aircraft. In addition to the requirement to rewire the aircraft, additional space had to be found to accommodate the ground fault interruption system.
One currently available ground fault interruption unit made by Autronics (model 2326-1) has been used in large commercial aircraft for the purpose of ground fault protection for fuel pumps. The Autronics unit detects a ground fault and outputs a signal indicative of a fault by use of a current transformer and acts by removing power to the fuel pump control relay.
There exists a need for an improved circuit protection device for aircraft. It would further be desirable for the circuit protection device to be included within an existing device in the aircraft, or to be packaged with an existing device, sharing the same connections to existing electrical circuits, since space for avionics is limited in any aircraft and adding wiring to accommodate a new device is very difficult. The present invention addresses these and other concerns.
SUMMARY OF THE INVENTION
Prior art systems for ground fault detection are helpful to reduce arcing in aircraft electrical systems, including aircraft fuel pumps. This issue has become a major concern of the Federal Aviation Administration and recent studies have promulgated a variety of studies and regulations in an attempt to prevent fuel tank ignition. One recent conference on fuel tank ignition prevention hosted by the FAA on the 20 and 21 of Jun. 2001 at the SEATAC Airport Hilton was given in order to better understand the provisions SFAR No. 88 and related certification procedures and airworthiness standards for transport category aircraft. A copy of the materials handed out and discussed at that meeting is attached hereto as Appendix A and incorporated herein by reference. Also attached as Appendix B is a copy of the Federal Register of Monday, May 7, 2001 relating to SFAR No. 88, “Fuel Tank System Fault Tolerance Evaluation Requirements and Related Airworthiness and Certification Standard”. These materials and this conference emphasized the importance of detecting ground faults and operating on the circuit to prevent, to the largest extent possible, arcing within fuel pumps and the like that may be exposed to flammable materials.
In addition to the Autronics Corporation Model No. 2326-1 series ground fault current detector previously discussed (and attached hereto as Appendix C), there also exists a ground fault detection system sold by PRIMEX Aerospace Company as Part No. 437, 437. A brochure for the PRIMEX system is attached as Appendix D. The PRIMEX system uses a current transformer to detect ground fault currents in three phase 400 Hertz motors. However, these prior art systems has serious limitations if they are to be broadly applied to aircraft, either as original equipment or retrofit, and they require separate wiring and space in addition to the currently existing equipment. The present invention offers many operational and functional advantages, in that it fits into the space available on the panel for the existing relays, utilizes the power of the system it is monitoring to operate, and is functionally faster and more efficient in detecting a ground fault and removing power from the system being monitored.
The present invention is a current imbalance detection and circuit interrupter particularly attractive for use in aircraft, for protecting a circuit having a line side and a load side. In a currently preferred embodiment, the present invention incorporates the current imbalance detection and circuit interrupter within the existing aircraft power control relay package. For example, in a fuel system application, the current imbalance detection and circuit interrupter is incorporated within the fuel pump control relay package. Therefore, the invention can be retrofit to existing aircraft, or can be utilized in newly constructed aircraft and new aircraft designs already incorporating the relay system. The current imbalance detection and fault circuit interrupter includes a housing, a power supply, a circuit to be monitored, a sensor, a logic controller, and a power controller (for example: relay, contactor, solid state relay, etc.). In a presently preferred embodiment, the invention can also include a fault indicator, a press to test switch and a reset switch. The power supply is configured to provide power to the sensor, logic controller and the power controller. The sensor is configured to sense a current imbalance in the circuit being monitored. In one presently preferred embodiment, the sensor to monitor current imbalance is a Hall effect sensor. The logic controller is configured to monitor a relay control input signal and to process inputs from the sensor.
In a presently preferred embodiment, the logic controller compares the sensor signal with predetermined limits representing acceptable operation and outputs a signal representing a circuit current imbalance when the sensor signal is outside the acceptable limits. The power controller is configured to receive input from the logic controller and remove power to the load side of the circuit when a current imbalance is sensed. In a presently preferred embodiment, the power removal from the load side of the circuit due to a sensed current imbalance is maintained until the power source to the current imbalance detection and circuit interrupter is cycled. In another presently preferred embodiment, power removal is maintained until a reset switch is activated. In a presently preferred embodiment, the fault indicator provides an indication of whether a current imbalance condition has occurred. A press to test switch may be included to check the operation of the unit during maintenance. In a presently preferred embodiment, the fault reset switch is used to reset the fault indicator.
The present invention also provides for a method for interrupting an electrical circuit for an electrical load, the electrical circuit having a line side and a load side with a ground fault. In summary, the method comprises providing a supply of power, continually monitoring and sensing the line side of the circuit for a current imbalance, continually monitoring the relay control input, receiving input from a logic controller and interrupting the relay control input signal when a current imbalance is sensed, and enabling the fault indicator. In one presently preferred aspect of the method, interrupting of the circuit when a current imbalance is sensed is maintained until the power source is cycled. Typically, the load being supplied with the current being monitored is a motor. In another preferred aspect, the current imbalance detection and circuit interrupter requires no additional signals, inputs, wiring, or sources of power, but takes its power from the circuit being monitored. In one presently preferred use of the method, the load side of the circuit is connected to a fuel pump, and arcing is terminated within the fuel pump.
In one presently preferred embodiment, the present invention is configured to perform ground fault detection and circuit interruption (GFI) and provides important advantages over prior art systems. Since the GFI system of the invention is packaged in the same envelope as an existing relay system, it can be readily retrofit to existing aircraft. Since it is easily operated off of either AC or DC circuits, containing its own power supply powered by the circuit being monitored, it can be used on either AC or DC wired aircraft without further change or rewiring in the aircraft. Furthermore, since the GFI system of the invention operates directly on and is part of the circuit being monitored, it avoids a major issue with prior art systems, which had to be separately connected to the circuit being monitored. Another substantial advantage to the present invention is that it more quickly removes power from the circuit with a fault, since sensing and control is at a single location, thus providing in situ sensing and control.
Most aircraft presently in service utilize circuit breakers with the limitations previously discussed. While the electronic and electromechanical aspects of the present invention impart additional protection to the protection provided by such circuit breakers, it would be desirable to be able to package the invention in a form which would allow ease of retrofit to existing aircraft, newly constructed and new aircraft designs, thus bringing the benefits of the invention to a wider range of applications. Accordingly, in a further presently preferred aspect of the invention, the electronic and electromechanical elements of the current imbalance detection and circuit interrupter are housed within a housing which has a similar form factor to prior art power controllers. The invention connects with the circuit to be monitored and controlled, through the existing power controller electrical connector, and it draws power from the circuit to be controlled. While there are numerous form factors which can impart additional protection to the protection provided by such circuit breakers, the most desirable form factors are related to the power controllers used in aircraft.
Other features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a block diagram of a first embodiment of a control system of the present invention adapted for a Boeing 757 aircraft, for interrupting the circuit when a current imbalance is sensed;
FIG. 2 illustrates a detailed view of the power supply portion of the control system shown in FIG. 1 ;
FIG. 3 illustrates a detailed view of the logic controller portion of the control system shown in FIG. 1 ;
FIG. 4 illustrates a detailed view of a sensor for the control system of FIG. 1 ;
FIG. 5 illustrates a block diagram of a second embodiment of a control system of the present invention adapted for a Boeing 747 aircraft, for interrupting the circuit when a current imbalance is sensed;
FIG. 6 illustrates a detailed view of the power supply portion of the control system shown in FIG. 5 ;
FIG. 7 illustrates a detailed view of the logic controller portion of the control system shown in FIG. 5 ;
FIG. 8 illustrates a detailed view of a sensor for the control system of FIG. 5 ;
FIG. 9 illustrates a block diagram of an alternate preferred embodiment of a control system of the present invention adapted for providing the speed of a DC relay in an AC application for interrupting the circuit when a current imbalance is sensed;
FIG. 10 illustrates a detailed view of a preferred embodiment of one section of the power supply portion of the control system shown in FIG. 9 ;
FIG. 11 illustrates a detailed view of a second section of the power supply portion of the control system shown in FIG. 9 ;
FIG. 12 illustrates a detailed view of the preferred logic controller portion of the control system shown in FIG. 9 ;
FIG. 13 illustrates a detailed view of a sensor for the control system of FIG. 9 ;
FIG. 14 is a side elevational view of an aircraft applicable current imbalance detection and circuit interrupter according to the present invention;
FIG. 15 is a rear view of the aircraft applicable current imbalance detection and circuit interrupter shown in FIG. 14 ;
FIG. 16 is a bottom view of the aircraft applicable current imbalance detection and circuit interrupter shown in FIG. 14 ;
FIG. 17 is a side elevational partial cutaway view of the aircraft applicable current imbalance detection and circuit interrupter shown in FIG. 14 ;
FIG. 18 is a sectional view of the aircraft applicable current imbalance detection and circuit interrupter taken along line 18 - 18 of FIG. 17 ; and
FIG. 19 is a sectional view of the aircraft applicable current imbalance detection and circuit interrupter taken along line 19 - 19 of FIG. 17 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a preferred embodiment of a control system 10 , adapted for a Boeing 757 aircraft, and FIG. 5 illustrates a preferred embodiment of a control system 10 , adapted for a Boeing 747 aircraft, each being constructed in accordance with the present invention for disconnecting power to a load when a current imbalance is sensed. Referring to FIGS. 1 and 5 , the aircraft applicable current imbalance detection and circuit interrupter 10 of the invention interrupts a circuit 20 having a line side 24 and a load side 26 with a ground fault. The load may be a motor, or any electrical device drawing a load, where protection of equipment or personnel is desired. The current imbalance detection and circuit interrupter of the invention includes a power supply 30 , a sensor 40 , a logic controller 50 , a power controller 60 , and a fault indicator and reset 55 . The power supply is configured to provide power to the logic controller, and the sensor is configured to sense a current imbalance in the line side 20 of the circuit 24 , and to output a sensor signal to the logic controller. The logic controller is configured to receive and process the sensor signal input from the sensor and the relay control input signal, and the power controller is configured to receive input from the logic controller and remove power to the load side of the circuit when a current imbalance is sensed.
FIGS. 2 and 6 illustrate a detailed view of a preferred embodiment of the power supply, and FIGS. 3 and 7 illustrate a detailed view of a preferred embodiment of the logic controller. Referring to FIGS. 4 and 8 , showing a sensor for use in the control system of the invention, in a preferred embodiment of the present invention, the sensor, which is an Amploc Pro 5 Hall effect linear current sensor with an output of 233 mV/A when operated at 10V. All three line side wires pass through the sensor core. Kirchoff's current law states that the net current in a node is 0. Considering the wye connection point of the load side pump winding, the net current in the phase windings, when algebraically summed, is 0. If a ground fault exists, that is where the current is supplied through the sensor but does not return through the sensor, the algebraic sum of the currents in the phase wires would be equal to the ground fault current.
Referring to FIGS. 3 and 7 , in a preferred embodiment, the output of the sensor is approximately one-half of the supply voltage, for no measured imbalance. Amplifier U 3 A amplifies the signal by a factor of 10. The gain is set by the ratio of resistors R 5 and R 3 . The 3 db point is where the reactance of capacitor C 4 is equal to the resistance of R 5 . This occurs at 3386 Hz. Resistors R 1 , R 2 , and R 4 bias the amplifier and have been selected so that a maximum value of 1 meg, for resistor R 4 , is required to adjust the amplifier output to mid supply with the sensor at its specified worse case high output. Calibration for the worse case low output of the sensor is easily achieved.
Amplifiers U 3 B and U 3 C, and resistors R 6 , R 7 , and R 8 are set to detect a current imbalance of 1.5±0.5 Arms. A high output from amplifier U 3 B or U 3 C indicates an imbalance is present in excess of the 1.5 Arms threshold. IC U 4 A “OR's” the outputs from amplifiers U 3 B and U 3 C. A logic 0 at its output indicates one or the other failure condition is present. Simultaneous imbalance inputs can be handled but are physically not possible since a positive imbalance cannot exist at the same time as a negative imbalance.
If a fault condition exists, it passes through IC U 5 A presenting a logic 1 to the latch comprised of ICs U 4 B and U 4 C. A logic 1, at pin 5 , forces the output pin 4 low, turning transistor Q 1 off, which removes the drive signal to the power control stage. Pin 9 , the other input to the latch, is normally at logic 0. This will cause pin 10 to go high, setting the latch by presenting a logic 1 to pin 6 .
In a preferred embodiment, the power-up sequence initializes the power control section to the non-operate mode. This is accomplished by presenting a logic 0 to pin 2 of IC U 5 A to mimic a current imbalance condition.
The power-up reset pulse created by IC U 5 B, resistor R 13 , capacitor C 5 and diode CR 8 is typically 7 msec. The reset is determined by the time it takes to charge capacitor C 5 through resistor R 13 to the threshold set by IC U 5 B. Diode CR 8 provides a quick reset.
Referring to FIGS. 2 and 6 , diodes CR 1 , CR 2 , CR 3 , CR 4 , CR 5 , and CR 6 form a full-wave three-phase bridge. Capacitor C 1 acts as the storage device for the 281V peak voltage produced by the bridge. The regulator is a preferably buck-type configuration with the abnormal architecture of having the inductor in the lower side. This is acceptable because the circuit does not have to be referenced to earth ground. In fact, the on-board electrical ground is approximately 270 V above earth ground.
Preferably, the switcher operates in a non-conventional mode. If it senses that output voltage is low, it turns on and remains on until the current through inductor L 1 reaches a pre-determined amount. Otherwise, the cycle is skipped. Energy is stored in inductor L 1 and transferred to output capacitor C 3 through diode CR 7 . Proper regulation is determined by Zener VR 1 and opto-coupler U 2 . Capacitor C 2 serves to store a small amount of energy that the regulator uses to operate its internal circuitry.
Referring to FIGS. 9-13 , illustrating an alternate preferred embodiment of a control system of the present invention adapted for an AC-DC application, to interrupt the circuit when a current imbalance is sensed. As is shown in FIG. 9 , the aircraft applicable current imbalance detection and circuit interrupter 10 of the invention interrupts a circuit 20 having a line side 24 and a load side 26 with a ground fault. The load may be a motor, or any electrical device drawing a load, where protection of equipment or personnel is desired. The current imbalance detection and circuit interrupter of the invention includes a power supply 30 , a sensor 40 , a logic controller 50 , a power controller 60 , and a fault indication and reset 55 . The power supply is configured to provide power to the logic controller, and the sensor is configured to sense a current imbalance in the line side 20 of the circuit 24 , and to output a sensor signal to the logic controller. The logic controller is configured to receive the relay control input signal and to receive and process the sensor signal input from the sensor, and the power controller is configured to receive input from the logic controller and remove power to the load side of the circuit when a current imbalance is sensed.
FIGS. 10 and 11 illustrate a detailed view of a preferred embodiment of the power supply. FIG. 12 illustrates a detailed view of a preferred embodiment of the logic controller. Referring to FIG. 13 , showing a sensor for use in the control system of the invention, in a preferred embodiment of the present invention, the sensor, which is an Amploc Pro 5 Hall effect linear sensor with an output of 233 mV/A when operated at 10V. All three line side wires pass through the sensor core. Kirchoff's current law states that the net current in a node is 0. Considering the wye connection point of the load side pump winding, the net current in the phase windings, when algebraically summed, is 0. If a ground fault exists, that is where the current is supplied through the sensor but does not return through the sensor, the algebraic sum of the currents in the phase wires would be equal to the ground fault current.
Referring to FIG. 12 , in a preferred embodiment, the output of the sensor is approximately one-half of the supply voltage, for no measured imbalance. Amplifier U 3 A amplifies the signal by a factor of 10. The gain is set by the ratio of resistors R 5 and R 3 . The 3 db point is where the reactance of capacitor C 4 is equal to the resistance of R 5 . This occurs at 3386 Hz. Resistors R 1 , R 2 , and R 4 bias the amplifier and have been selected so that a maximum value of 1 meg, for resistor R 4 , is required to adjust the amplifier output to mid supply with the sensor at its specified worse case high output. Calibration for the worse case low output of the sensor is easily achieved.
Amplifiers U 3 B and U 3 C, and resistors R 6 , R 7 , and R 8 are set to detect a current imbalance of 1.5±0.5 Arms. A high output from amplifier U 3 B or U 3 C indicates an imbalance is present in excess of the 1.5 Arms threshold. IC U 4 A “OR's” the outputs from amplifiers U 3 B and U 3 C. A logic 0 at its output indicates one or the other failure condition is present. Simultaneous imbalance inputs can be handled but are physically not possible since a positive imbalance cannot exist at the same time as a negative imbalance.
If a fault condition exists, it passes through IC U 5 A presenting a logic 1 to the latch comprised of ICs U 4 B and U 4 C. A logic 1, at pin 5 , forces the output pin 4 low, turning transistor Q 1 off, which removes the drive signal to the power control stage. Pin 9 , the other input to the latch, is normally at logic 0. This will cause pin 10 to go high, setting the latch by presenting a logic 1 to pin 6 .
In a preferred embodiment, the power-up sequence initializes the power control section to the non-operate mode. This is accomplished by presenting a logic 0 to pin 2 of IC U 5 A to mimic a current imbalance condition.
The power-up reset pulse created by IC U 5 B, resistor R 13 , capacitor C 5 and diode CR 8 is typically 7 msec. The reset is determined by the time it takes to charge capacitor C 5 through resistor R 13 to the threshold set by IC U 5 B. Diode CR 8 provides a quick reset.
Referring to FIGS. 10 and 11 , diodes CR 1 , CR 2 , CR 3 , CR 4 , CR 5 , and CR 6 form a full-wave three-phase bridge. Capacitor C 1 acts as the storage device for the 281V peak voltage produced by the bridge. The regulators are a buck-type configuration with the abnormal architecture of having the inductor in the lower side. This is acceptable because the circuit does not have to be referenced to earth ground. In fact, the on-board electrical ground is approximately 270V and 260V above earth ground for the 10 V and 20V supplies respectively.
Preferably, the switcher operates in a non-conventional mode. If it is sensed that an output voltage is low, the corresponding controller turns on and remains on until the current through inductor L 1 or L 1 A reaches a pre-determined amount. Otherwise, the cycle is skipped. Energy is stored in inductor L 1 or L 1 A and transferred to output capacitor C 3 or C 3 A through diode CR 7 or CR 7 A. Proper regulation is determined by Zener VR 1 or VR 1 A and opto-coupler U 2 or U 2 A. Capacitor C 2 or C 2 A serves to store a small amount of energy that each respective regulator uses to operate its internal circuitry.
Most aircraft presently in service utilize circuit breakers with the limitations previously discussed. While the electronic and electromechanical aspects of the present invention impart additional protection to the protection provided by such circuit breakers, it would be desirable to be able to package the invention in a form which would allow ease of retrofit to existing aircraft, newly constructed and new aircraft designs, thus bringing the benefits of the invention to a wider range of applications. Accordingly, in a further presently preferred aspect of the invention, the electronic and electromechanical elements of the current imbalance detection and circuit interrupter are housed within a housing which has a similar form factor to prior art power controllers. The invention connects with the circuit to be monitored and controlled through the existing power controller electrical connector, and it draws power from the circuit to be controlled. While there are numerous form factors which can impart additional protection to the protection provided by such circuit breakers, one of our form factors is related to the power controllers used in the Boeing 757 aircraft and the like, which have an installed height of approximately 1.78 inches above the mounting surface, a width of approximately 1.53 inches above the mounting surface, and a total height of 3.28 inches from the top to the bottom of the electrical terminals.
With reference to FIG. 14 , in one presently preferred aspect of the invention, each of the above described circuit configurations can be advantageously contained in a corresponding housing 70 , which is typically no more than about 3.28 inches (about 8.33 cm.) from top 72 to bottom 74 , no more than about 1.53 inches (about 3.89 cm.) wide along its front 76 and rear 78 sides, and no more than about 2.51 inches (about 6.38 cm.) from the front side 80 of the front mounting flange 82 to the rear side 84 of the rear mounting flange 86 . The housing also includes a relay 87 . Referring to FIG. 14 , FIG. 15 , and FIG. 16 , an electrical connector means such as the terminal block or connector plate 88 is provided at the bottom of the aircraft applicable current imbalance detection and circuit interrupter housing, typically with eight screw-type electrical connectors, A 1 , A 2 , X 1 , B 1 , B 2 , C 1 , C 2 , and X 2 , although other conventional types of wire connectors may also be suitable. Referring to FIG. 4 , FIG. 8 , FIG. 13 and FIG. 16 , the connectors A 1 and A 2 accommodate a first line and load A; the connectors B 1 and B 2 accommodate a second line and load B, and the connectors C 1 and C 2 will accommodate a third line and load C. As is shown in FIG. 15 and FIG. 16 , the connector plate is mounted to the housing of the aircraft applicable current imbalance detection and circuit interrupter by mounting screws 90 , which extend through sleeves 92 in the housing, illustrated in FIG. 18 and FIG. 19 , as is explained further below.
Referring to FIG. 17 , FIG. 18 and FIG. 19 , one or more circuit boards, such as a first printed circuit board 94 and a second printed circuit board 96 , for mounting the components of the above described circuit configurations, can be mounted within the housing with notches 98 in the printed circuit boards fitting around the sleeves 92 of the mounting screws 90 .
From the above, it may be seen that the present invention provides a method and apparatus for suppressing arcs in electrical equipment in aircraft which may be adapted to a variety of systems and components. As such, it provides additional reliable and rapid disconnect of power to the existing systems, thus reducing damage from ground faults in the circuits. While a particular form of the invention has been illustrated and described it will also be apparent that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited except as by the appended claims. | The aircraft applicable current imbalance detection and circuit interrupter interrupts an electrical circuit when a current imbalance is sensed. The current imbalance detection and circuit interrupter includes a housing, power supplies, a sensor for sensing a current imbalance at the line side of the electrical circuit, a logic controller and a power controller. In a preferred embodiment, the invention can also include a fault indicator, a press to test switch and a reset switch. The power supplies provide power to the sensor, logic controller, and the power controller. The logic controller receives input from the sensor and the relay control signal, and the power controller receives input from the logic controller, and interrupts power to the load side of the electrical circuit when the sensor senses a current imbalance. Power interruption due to a sensed current imbalance is maintained until the line side power source is cycled. The circuit interrupter is preferably autonomous, requiring no additional signals, inputs, wiring or sources of power. The current imbalance detection and circuit interrupter is packaged in a configuration integral with the power controller, thus easing retrofit with the improved aircraft applicable current imbalance detection and circuit interrupter. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application Ser. No. 61/240,061, filed Sep. 4, 2009, hereby incorporated by reference in its entirety for all of its teachings.
ACKNOWLEDGEMENTS
This invention was made with government support under Grant FA8650-07-1-5908 awarded by the United States Air Force. The government has certain rights in the invention.
BACKGROUND
A class of compounds termed N-halamines has been shown to provide excellent antimicrobial properties, particularly for polymers and coatings containing these functional groups. These compounds possess the advantage that their precursors can be chlorinated or brominated in situ to produce biocidal activity and be rehalogenated when the oxidative halogen on the compounds has been exhausted. For example, poly-styrene derivatized with N-chlorinated or N-brominated hydantoinyl functional groups can be used to disinfect potable water (see U.S. Pat. Nos. 5,490,983, 6,548,054 B2, 7,687,072 B2) and, as a matter of fact, is currently being used for water disinfection by low-income families in developing nations such as India. The N-halamine polymer technology can further be applied to produce antimicrobial coatings on surfaces such as textiles (see for example, U.S. Pat. Nos. 6,969,769 B2, 7,335,373 B2, 5,882,357). It has recently been demonstrated that the N-chlorinated hydantoinyl siloxane polymer addressed in U.S. Pat. No. 6,969,769 B2 can also be used in detoxification of chemical agents (Salter, et al., J. Mater. Sci., 44, 2069 (2009)). Any N-halamine coating will be antimicrobial and capable of detoxification since the bound halogen is oxidative upon transfer to receptor sites. Heretofore, two limitations of N-halamine polymer coatings have been their oxidative halogen loading capacities (less than 1% by weight chlorine) and their lack of resistance to ultraviolet photodegradation. Thus, it would be desirable to create an N-halamine polymer coating which could load a higher weight percentage of halogen, so as to increase its biocidal and detoxification efficacies (lower contact times necessary for complete inactivations of pathogens and toxic chemical agents) and which could resist ultraviolet photodegradation in sunlight.
Meta-aramid (poly-m-phenylene isophthalamide), generally sold under the trade name Nomex™, is known to be an excellent fire-resistant polymer. It can be prepared by reaction of isophthaloyl chloride with m-phenylene diamine in a solvent such as tetrahydrofuran (see for example U.S. Pat. No. 3,287,324). It is used in commerce in the form of a fiber or film. It contains an acyclic amide nitrogen atom which can be halogenated by exposure to aqueous free chlorine or bromine (see chemical structure below). It has been shown that Nomex fibers achieve
chlorination with aqueous household bleach with much less decomposition than does its isomer p-aramid, trade name Kevlar, (see Sun and Sun, Ind. Eng. Chem. Res., 43, 5015 (2004)); however, a maximum concentration of only about 0.1 weight percent of oxidative chlorine (expressed as wt % Cl + ) could be loaded onto the Nomex fibers in that work. This loading demonstrated antibacterial activity for the fibers, but the loading decreased substantially over time and under washing conditions, and only 0.1 wt % chlorine would not be able to provide sustained biocidal activity. Sandstrom and Sun extended the Nomex fiber work to a study of thermal and UV stability for chlorinated Nomex in firefighter uniforms (Sandstrom and Sun, RJTA, 10, 13 (2006); Sandstrom et al., Tex. Res. J., 77, 591 (2007)). Again the fibers contained very low chlorine loadings (less than 0.1 wt %), but the authors noted some UV stability over a one hour irradiation period as long as the fibers were maintained in a very dry state. Under controlled humidity tests in a weathering chamber the chlorinated fibers were not thermally or photolytically stable. It has also been shown that the loading of chlorine can be increased for fibers containing a blend of Nomex polymer and cellulose up to almost 1 wt % if Nomex and cellulose are dissolved in an ionic liquid solvent and co-extruded into fibers (see Lee et al., J. Eng. Fib. Fab., 2, 25 (2007)). Upon chlorination, the fibers became bactericidal. However, when the Nomex polymer content in the blended fibers was above 10 weight percent, the tenacities of the fibers were dramatically decreased rendering them impractical for commercial use. A similar study has been recently reported for a Nomex-coated/polyethylene terephthalate prepared by applying a dimethylacetamide solution of Nomex to PET fabric using a pad-dry-curing process (Kim et al., J. Appl. Polym. Sci., 114, 3835 (2009)). The treated Nomex/PET was antibacterial but only could load about 0.4 wt % chlorine which again would not provide sustained antimicrobial activity. The detoxification study mentioned above (Salter, et al., J. Mater. Sci., 44, 2069 (2009)) employed Nomex derivatized with the hydantoinyl siloxane of U.S. Pat. No. 6,969,769 B2. The chlorine loadings in that study were about 0.32 wt % which would be too low for sustained detoxification activity. In summary, loadings of more than 1 wt % chlorine on Nomex fibers or its co-polymer blends and sustainable UV stability under real-world conditions have not been obtained heretofore. The most probable reason for this is that the oxidative chlorine is not able to penetrate the surfaces of the fibers due to lack of porosity and low permeability of the chlorine into the polymer structure. Hence any antimicrobial or detoxification activity of the treated Nomex fibers will be short-lived due to rapid exhaustion of the bound oxidative chlorine on the surfaces of the fibers.
Thus, porous, permeable antimicrobial/detoxification particles of Nomex or its blends with other polymers such as cellulose, cellulose acetate, polyurethane, and the like, would be desirable because they should bind much more oxidative chlorine than do non-porous fibers which would enable extended antimicrobial and detoxification activity and possibly less photodegradation due to the fact that much of the halogen would be less accessible to the UV photons when buried within the pores than those halogens bound on the surface. The N-halamine polymeric biocide as an amorphous solid, which is the subject of U.S. Pat. No. 5,490,983, has been broadcast into nonwoven webs for use in personal care absorbent articles (see US Patent 2003/0144638 A1) and shown to work well for this application. The current invention which involves Nomex particles and its blends should work well in similar applications for providing antimicrobial activity as well as in numerous other applications such as water and air filters, military textiles, health care textiles, paints, and other coatings. A byproduct of antimicrobial activity is the destruction of noxious odors in personal care absorbent articles, textiles, paint coatings in medical facilities, and the like. A distinct advantage of the treated Nomex and Nomex blend particles will be its lower cost relative to other biocidal particles such as that disclosed in U.S. Pat. No. 5,490,983 and 2003/0144638 A1.
Previous work on Nomex and Nomex blends relates to the materials existing as fibers, not porous particles.
SUMMARY OF THE INVENTION
The invention relates to porous microscopic particles of Nomex and its blends with other polymers such as, but not limited to, cellulose, cellulose acetate, polyurethane, and the like. A second aspect of the invention relates to halogenation of the amide nitrogen atoms of the Nomex moieties in porous particle form so as to produce high weight percent loadings of covalently bound oxidative chlorine or bromine for the purpose of inactivating microorganisms and detoxifying chemical agents. A third aspect of the invention relates to substantially increasing the oxidative halogen loading of the Nomex and Nomex/polymer blends relative to previous work involving Nomex fibers. A fourth aspect of the invention relates to providing increased stability toward ultraviolet photodegradation for the halogenated Nomex and Nomex/polymer blends. A fifth aspect of the invention relates to the utility of the halogenated Nomex and Nomex/polymer blends in nonwoven webs, absorbent articles, textiles, health care products, paints, water and air filters, and the like.
The present invention relates to the preparation of the porous Nomex and Nomex/polymer blended particles and to the halogenation thereof with aqueous free chlorine or bromine. It also relates to the broadcasting of the particles into various matrices such as nonwovens, paints, paper, filters, and the like. Additional advantages will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the aspects described below. The advantages described below will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several aspects described below.
FIG. 1A shows an untreated water filter with no particles present on the filter. FIG. 1B shows unchlorinated Nomex porous particles effectively captured in an embedded filter swatch.
DETAILED DESCRIPTION
Before the present compounds, compositions, articles, devices, and/or methods are disclosed and described, it is to be understood that the aspects described below are not limited to specific preparation methods; specific preparation methods may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.
In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings:
It must be noted that, as used in the specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to an “unhalogenated compound” can include two or more such compounds.
Ranges may be expressed as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.
References in the specification and appended claims to weight percent (wt %) of a particular element or component in a composition or article, denote the weight relationship between the particular element or component and the total weight of the formulation or composition in which the element or component is included.
As used herein, the terms “antimicrobial” and “biocidal” means activity which inactivates or kills microorganisms.
As used herein, the terms “detoxify” or “detoxification” mean destruction of toxic chemical agents.
As used herein, the term “photodecomposition” means destruction of an element or component in a composition or article by exposure to ultraviolet (UV) photons.
As used herein, the term “Nomex” means the compound poly-m-phenylene isophthalamide, first registered by DuPont, Inc. as the fiber Nomex™. It is to be understood that the polymer poly-m-phenylene isophthalamide is easily synthesized in the laboratory and is available from several commercial sources under various trade names. For example, the term “Nomex” as used herein refers to the polymer structure below having the chemical name poly-m-phenelene isophthalamide, which can exist as fibers or films, or in a mixture with other polymers.
As used herein, the term “unhalogenated Nomex” means the structure below in which each X is H:
As used herein, the term “halogenated Nomex” means the structure above in which at least one X is Cl or Br.
As used herein, the term “Nomex blend” means a blend of Nomex with any other polymer such as, for example, cellulose, cellulose acetate, polyurethane, and the like.
As used herein, the term “matrix” means material into which particles can be inserted such as nonwovens, textiles, paints, filters, absorbent articles, and the like.
As used herein, the term porous means a structure which allows permeation of halogen (e.g., halogenating agents) throughout the structure, whether by liquid flow into defined openings or pores, or by diffusion through the solid substance of the particle. Not wishing to be bound by theory, both porosity and permeability, or diffusion are likely mechanisms operative in the invention, and the term “porosity” or “porous” is intended to include both.
The present invention may be understood more readily by reference to the following detailed description of specific embodiments and the examples included therein.
Porous particles of Nomex can be produced by dissolving Nomex polymer (e.g., fibers or films) in an ionic liquid like 1-butyl-3-methylimidazolium chloride or an organic solvent such as DMF, followed by rapidly precipitating the dissolved Nomex in a stirred excess non-solvent (for the polymer) such as water or ethanol. Porous particles of Nomex blends can be produced by dissolving a mixture of Nomex polymer and other polymers such as, for example, cellulose, cellulose acetate, polyurethane, and the like in an ionic liquid like 1-butyl-3-methylimidazolium chloride or an organic solvent such as DMF followed by rapidly precipitating the dissolved Nomex blend in a stirred excess solvent such as water or ethanol dependent on the nature of the polymer. Ethanol could be used for cellulose or cellulose acetate. Small amounts of an inorganic salt such as lithium chloride are occasionally needed for complete dissolution when organic solvents are employed. A preferred weight percent of Nomex in the blend should be about 2 to 10. The Nomex blends can also contain superabsorbent polymers such as starch so as to absorb moisture which can enhance their biocidal and detoxification activities. In one aspect, the unhalogenated Nomex porous particles have a diameter from 0.5 μm to 10 μm. In another aspect, the particle diameter is 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm, wherein any value can provide a lower and upper limit of the diameter range.
After producing the unhalogenated Nomex particles using the techniques described above, the unhalogenated Nomex particles can be halogenated by contacting the particles with a suitable halogenating agent. The degree of halogentation can vary depending upon reaction conditions, ranging from partial halogentation to complete halogentation of the unhalogenated Nomex particles. In one aspect, the porous Nomex particles or Nomex particle blends can be chlorinated by soaking the particles at ambient temperature in dilute aqueous solutions of about 10 wt % household bleach (sodium hypochlorite). The pH should be controlled in the range of 7 to 11, with pH 7 preferred for high chlorine loadings (greater than 6 wt % chlorine). Alternative chlorination sources such as calcium hypochlorite, chloroisocyanurates, dichlorohydantoins, and t-butyl hypochlorite, the latter if organic solvents are used, can be employed. In other aspects, bromination of the Nomex particles or Nomex particle blends can be achieved by soaking in aqueous bromine solution (see Example 7). Other bromination reagents which could be used include sodium or potassium bromide in the presence of an oxidizer such as potassium peroxy monosulfate and brominated hydantoins. Halogenation of the Nomex particles or Nomex particle blends can also be effected after the unhalogenated particles are broadcast into a matrix such as a nonwoven, textile, filter, paint, absorbent article, and the like. In one aspect, the halogenated Nomex porous particles have a diameter from 0.5 μm to 10 μm. In another aspect, the particle diameter is 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm, wherein any value can provide a lower and upper limit of the diameter range. In another aspect, the halogen content of the particle is from 0.5% to 20% by weight of the particle. In another aspect, the halogen content of the particle is from 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18, or 20% by weight of the particle. In a further aspect, the halogen content of the particle is from 2-fold, 3-fold, 4-fold, 5-fold, 10-fold, 20-fold, 30-fold, 40-fold, 50-fold, 75-fold, or 100-fold greater when compared to halogenating a commercial Nomex fiber.
Any of the particles and particle blends described herein can be incorporated into a matrix. For example, halogenated Nomex particles or particle blends can be biocidal and capable of detoxification of chemical agents. Since the great majority of the bound chlorine or bromine sites are contained within the pores of the particles, they also become resistant to photodecomposition. Since the weight percent halogen obtainable for the particles is much higher than that possible for Nomex fibers and Nomex fiber blends, the efficacy at disinfection and detoxification will be greater.
The particles can be broadcast into matrices or onto surfaces in a variety of ways including, but not limited to, soaking in solvents, followed by drying at elevated temperatures (up to 50° C. if already halogenated), blowing them into the matrix, or depositing them onto a surface.
One of skill in the art may determine alternative means of producing Nomex particles or Nomex particle blends and alternative means of broadcasting them into matrices.
The present invention is more particularly described in the following examples which are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art.
EXAMPLES
The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compounds, compositions, articles, devices, and/or methods described and claimed herein are prepared and evaluated, and are intended to be purely exemplary, and are not intended to limit the scope of what the inventors regard as their invention. There are numerous variations and combinations of preparation conditions, e.g. component concentrations, desired solvents, solvent mixtures, temperatures, pressures, and other preparation conditions that can be used to optimize the halogen loading obtained from the described process. Only reasonable and routine experimentation will be required to optimize such process conditions.
Example 1
Preparation of Unhalogenated and Chlorinated Porous Nomex Particles
50 grams of an ionic liquid, 1-buthyl-3-methyl-imidazolium chloride (Aldrich Chemicals Inc.) were added to a round bottom flask containing 0.62 gram of Nomex™ (DuPont, Corp.) fibers which were cut into small pieces to improve mixing. The solution was stirred with a mechanic stirrer at 80° C. for 72 hours until the fiber was completely dissolved. The solution was withdrawn with a syringe and precipitated in 200 mL of ethanol accompanied by vigorous agitation using a household blender. A uniform hazy suspension (ethanol, aramid, and ionic liquid) was produced. The cloudy suspension was filtered using a filter paper and then washed with distilled water and dried in air. The diameters of the resulting porous Nomex particles were between 1 and 2 μm.
The particles were then chlorinated using a commercial household hypochlorite bleach solution diluted 9/1 with tap water. The pH was adjusted to 7 using 6 N hydrochloric acid. The particles were placed in the solution for 1 hour at room temperature with mild stirring. The particles were then collected on filter paper, rinsed thoroughly with distilled water, and dried for 1 hour at 45° C. to remove any residual free chlorine.
The particles were analyzed for retained chlorine using a modified iodometric/thiosulfate titration procedure. In a 125 mL conical flask, 0.25 g of potassium iodide was dissolved in 10 mL of 0.1 N acetic acid and 90 mL of absolute ethanol. Weighed particles were added to the flask, and standardized 0.00375 N sodium thiosulfate solution was slowly added to the flask until reaching the endpoint (from yellow to colorless), and the solution remained colorless for 1 min. The amount of sodium thiosulfate solution consumed was recorded. The following equation was used to determine the weight percent Cl + loading on particles.
Cl + wt %=( N×V× 35.45)/(2× W )×100%
where N and V are the normality (eqv/L) and volume (L), respectively, of the sodium thiosulfate consumed in the titration, and W is the weight of the samples in grams. The chlorine content of the chlorinated particles (Nomex-Cl) was measured as 6.72 wt %. The active chlorine loading of the particles was significantly higher compared to Nomex fibers as received, which was only 0.11 wt % at the same chlorination conditions.
Example 2
Preparation of Unhalogenated and Chlorinated Porous Nomex/Cellulose Particles
24 grams of an ionic liquid (1-buthyl-3-methyl-imidazolium chloride), were added to a flask containing 0.5 g Nomex™ aramid fibers which were cut into small pieces to improve mixing. They were stirred in a centrifugal mixer at 2500 rpm for about 20 minutes until the fiber was soaked by the ionic liquid. Then 0.5 grams of ground bleached cotton cellulose was added to the above solution, and mixing was continued for 1 hour. The solution was heated at 80° C. for 1 hour to lower the solution viscosity. Mixing and heating were repeated alternately to complete dissolution. The above solution was subsequently diluted by 3/1 with additional solvent.
The solution then was withdrawn with a syringe and injected into 200 mL of ethanol while undergoing vigorous agitation with a household blender. A uniform hazy suspension (ethanol, aramid, cellulose, and ionic liquid) was observed. Upon standing, a cloudy agglomeration began to settle from the suspension. Before complete agglomeration, the cloudy suspension was centrifuged, and the top clear solution was decanted. The collected aramid/cellulose sample was re-suspended in distilled water and centrifuged twice more, and then re-suspended in 180 mL of distilled water. Commercial household hypochlorite bleach (20 mL) was added, and the pH value was adjusted to 7 using 6 M hydrochloric acid. The chlorination solution was stirred at room temperature for 1 hour. The particles obtained were again centrifuged, washed at least 3 times with water, and then dried in a freeze dryer, followed by drying in air at 45° C. for 1 hour to remove any residual free chlorine.
The Nomex/cellulose porous particles obtained were analyzed for retained chlorine using a standard iodometric/thiosulfate titration procedure. The average chlorine content of the Nomex/cellulose particles was 4.31 wt % for four independent trials.
Example 3
Preparation of Unhalogenated and Chlorinated Permeable Nomex/Cellulose Blended Films from Particles
24 grams of an ionic liquid (1-butyl-3-methylimidazolium chloride) were added to a flask containing 0.5 gram of Nomex™ fibers which were cut into small pieces to improve mixing. The solution was stirred in a centrifugal mixer at 2500 rpm for about 20 minutes until the fiber was well dispersed. Then 0.5 gram of ground bleached cotton cellulose was added to the above solution, and mixing and heating to 80° C. were repeated alternately to complete dissolution. To lower the solution viscosity, it was diluted 3/1 with additional solvent.
The solution was withdrawn with a syringe and injected into 200 mL of ethanol during vigorous agitation effected by a household blender. A uniform hazy suspension (ethanol, aramid, cellulose, and ionic liquid) was produced. Upon standing, a cloudy agglomeration began to settle from the suspension. The cloudy suspension was stirred and filtered through a filter paper and allowed to dry in air. While wet, the particles could be re-suspended from the filter paper into water, but if allowed to dry, the particles adhered to each other on the filter paper and to the filter paper, forming a film. The film could be separated from the filter paper in small pieces.
The pieces of film were chlorinated using commercial household hypochlorite bleach diluted 9/1 with distilled water. Two bleach solutions were prepared, one adjusted to pH 9 with sodium bicarbonate, and a second adjusted to pH 7 using 6 N hydrochloric acid. Film samples were placed in each of the solutions for 1 hour at room temperature with mild stirring. The chlorinated film samples were collected on filter paper, rinsed thoroughly with distilled water, and dried for 1 hour at 45° C. to remove any residual free chlorine.
The samples were analyzed for retained chlorine using a standard iodometric/thiosulfate titration procedure. The chlorine contents of the blended film samples chlorinated at pH 7 and 9 were measured to be 6.08 wt % and 4.7 wt %, respectively. Thus higher chlorine loadings can be obtained at neutral pH, and much higher chlorine loadings can be obtained for porous Nomex/cellulose blended particles than for blended fibers. The adherence of the particles to each other and to paper upon drying suggests that they might adhere to a substrate matrix without binder if applied wet and then subsequently dried.
Example 4
Application of Porous Nomex Particles to a Commercial Filter Medium and Evaluation of its Antimicrobial Performance
0.06 gram of unchlorinated porous Nomex particles, as described in Example 1, were dispersed in 500 mL of distilled water, and the dispersion was filtered through a commercial water filter material (Argonide™, Argonide Corp.) ( FIG. 1A ), which weighed 1.14 grams and was 3 inches in diameter. The particles were effectively captured, and after drying were quite well trapped in the filter ( FIG. 1B ). The same procedure was used to prepare an embedded filter swatch with the chlorinated particles (Nomex-Cl, 6.72 wt % Cl + ) described in Example 1. The chlorine content of the chlorinated particle embedded filter swatch was measured as 0.29 wt % relative to the weight of the whole filter swatch.
Both Nomex and Nomex-Cl particle-embedded filters were subsequently evaluated for antibacterial effects. The treated filter swatches were challenged with Escherichia coli O157:117 (ATCC 43895) bacterial suspensions. 25 μl of the bacterial suspension were added to the center of a 1 inch square filter swatch, and a second identical swatch was laid on the first swatch held in place by a sterile weight. The contact times for the swatches with the bacteria were 15 and 30 minutes. At those contact times the filter swatches were quenched with 0.02 N sodium thiosulfate solution to remove any oxidative chlorine which could cause extended disinfection. Serial dilutions of the solutions contacting the surfaces were plated on Trypticase agar, incubated for 24 hours at 37° C., and colony counts were made to determine the presence of viable bacteria.
As shown in Table 1, the unchlorinated control samples, Nomex, provided 4.37 log reduction, due to the adhesion of bacteria to the filter swatches (wood-pulp), within a 30 minute contact time interval. In general, 4 log reductions for control samples are relatively high; however, nano alumina-grafted microglass fibers in the filter offer bacteria a high surface area for adhesion. The chlorinated filter samples, Nomex-Cl, showed excellent antimicrobial activity. All E. coli bacteria were inactivated by the treated swatches within the contact interval of 30 minutes. The inactivating rates of the chlorinated treated swatches are not sufficient for disinfection applications for flowing potable water; however, they would be sufficient for use in inactivating bacteria trapped in the filters over a period of time, thus making the filters safe for workers who eventually have to handle the filters.
TABLE 1
Biocidal activity of chlorinated Nomex-particle embedded filter.
Contact
Total
Bacterial
time
bacteria
reduction
Sample
(min)
(Log)
(Log)
Inoculum
7.10
Nomex Filter (control)
30
2.73
4.37
Nomex-Cl Filter
15
2.53
4.57
30
0
7.10
Example 5
Stability Toward Irradiation with Ultraviolet Photons
UV light stability of the bound chlorine on the porous Nomex particles was measured by using an Accelerated Weathering Tester (The Q-panel Company, Cleveland, Ohio, USA). The samples were placed in the UV (Type A, 315-400 nm) chamber for times in the range of 3 to 72 hours. After a specific time of exposure to UV irradiation, the samples were removed from the UV chamber and titrated, or rechlorinated and titrated. The temperature in the chamber was 37.6° C., and the relative humidity was 17% during the UVA light irradiation.
The UVA light stability of the N—Cl bond of the particles is summarized in Table 2. The chlorinated porous Nomex particles (Nomex-Cl) lost only 22 wt % of bound chlorine within 24 hours of UVA light exposure. In addition, almost all of the initial chlorine loading was provided upon rechlorination indicating little significant decomposition of the polymer itself in the presence of the UVA irradiation over the entire 24 hours of exposure. Porous Nomex-Cl particles were further investigated through UVA light exposure and rechlorination cycles. The chlorine loss was 37% within 72 hours of UVA light exposure indicating the presence of very stable N—Cl bonds, and/or the N—Cl bonds were protected from UVA exposure by the phenyl moieties or by their submersion in the pores of the particles. Consequently, the stability was quite remarkable given that a time period of exposure in the UV chamber was equivalent to the same time in direct midday summer sunlight.
TABLE 2
Stability toward UV light exposure of porous
Nomex-Cl (Cl + wt % remaining) particles.
Exposure Time
Cl + wt %
% Chlorine Loss
0
6.79
3 hours
6.32
7
24 hours
5.33
22
Rechlorination
6.59
72 additional hours
4.27
37
Rechlorination
6.51
24 additional hours
5.20
23
Rechlorination
6.36
24 additional hours
5.45
20
Rechlorination
6.42
24 additional hours
5.52
19
Rechlorination
6.38
Example 6
Preparation of Unhalogenated and Chlorinated Porous Nomex/Cellulose Acetate Particles
0.1 g Nomex™ aramid fibers, which were cut into small pieces to improve dissolution, and 0.42 g LiCl were added to a flask containing 20 mL of dimethylacetamide (DMAc); the mixture was heated at 120° C. for 2 hours to complete dissolution. The solution was filtered to remove a small amount of residual undissolved material. Then 0.1 g cellulose acetate (Eastman Chemical Company, Degree of Substitution=1.7) was added to the solution, followed by heating at 50° C. for 1.5 hours.
The above solution was transferred to a syringe and injected into 200 mL of distilled water with vigorous agitation by a household blender. A uniform suspension (water, aramid, cellulose acetate, and DMAc) with some foam on the top was observed. After collapsing the foam, 20 mL of commercial household hypochlorite bleach was added to 180 mL of the above suspension so that the concentration of sodium hypochlorite was 0.6 wt % active chlorine. The chlorination was performed at room temperature for 1 hour at pH 7 which was adjusted by adding 6 M hydrochloric acid while mild stirring was applied. In order to separate aramid/cellulose acetate from the chlorination bath, the chlorinated aramid/cellulose acetate suspension was centrifuged, and the clear solvent was decanted. The precipitated porous particles were resuspended and washed in distilled water, followed by centrifgugation three times. Then they were freeze dried and heated in air at 45° C. overnight to remove any residual free chlorine.
The collected particles of blended Nomex polymer/cellulose acetate were analyzed for retained chlorine using a standard iodometric/thiosulfate titration procedure. The chlorine content of the particles was 4.05 wt %.
Example 7
Preparation of Brominated Porous Nomex Particles
Nomex particles as described in Example 1 (0.15 g) were suspended in a 100 mL flask containing 50 mL of 2 N sodium hydroxide. To the stirred suspension was added dropwise bromine (0.3 g) over a period of 10 minutes. After stirring for 5 min, the pH was adjusted to 7 by the addition of 4 N acetic acid, the flask was sealed, and the mixture was stirred at room temperature for 1 hour. The brominated particles were then filtered, rinsed thoroughly with distilled water, and dried for 1 hour at 45° C. to remove any residual free bromine.
The particles were analyzed for retained bromine using a modified iodometric/thiosulfate titration procedure as in Example 1. The following equation was used to determine the weight percent Br + loading on the particles:
Br + wt %=( N×V× 79.90)/(2× W )×100%
where N and V are the normality (eqv/L) and volume (L), respectively, of the sodium thiosulfate consumed in the titration, and W is the weight of the sample in grams. The bromine content of the brominated particles (Nomex-Br) was measured as 4.09 wt %.
Example 8
Preparation of Unhalogenated and Chlorinated Porous Nomex/Polyurethane Particles
0.21 g Nomex™ aramid fibers, which were cut into small pieces to improve dissolution, and 0.84 g LiCl were added to a flask containing 40 mL dimethylformamide (DMF); the mixture was heated at 120° C. for 2 hours to complete dissolution. The solution was filtered to remove a small amount of residual undissolved material. Then 0.21 g polyurethane was added to the solution, followed by heating at 50° C. for 0.5 hours.
The above solution was injected into 200 mL of ethanol with vigorous agitation by a household blender. A uniform suspension (ethanol, aramid, polyurethane and DMF) was centrifuged to collect aramid/polyurethane particles which were re-suspended into water and centrifuged twice more followed by freeze drying. Aramid/polyurethane particles were chlorinated in a solution consisting of 180 mL distilled water and 20 mL commercial household hypochlorite bleach at pH 7 which was adjusted by adding 6 M hydrochloric acid. The chlorination was performed at room temperature for 1 hour while mild stirring was applied. In order to separate the chlorinated aramid/polyurethane from the chlorination bath, the chlorinated aramid/polyurethane suspension was centrifuged, and the clear solvent was decanted. The precipitated porous particles were resuspended and washed in distilled water, followed by centrifugation three times. Then they were freeze dried and heated in air at 45° C. for 1 hour to remove any residual free chlorine.
The collected particles of blended Nomex/polyurethane were analyzed for retained chlorine using a modified iodometric/thiosulfate titration procedure as in Example 1. The chlorine content of the particles was 4.17 wt %.
Throughout this application, various publications are referenced. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the invention.
Various modifications and variations can be made to the compounds, compositions, and methods described herein. Other aspects of the compounds, compositions, and methods described herein will be apparent from consideration of the specification and practice of the compounds, compositions, and methods disclosed herein. It is intended that the specification and examples be considered as exemplary. | Porous, permeable particles of meta-aramid can be chlorinated or brominated to produce antimicrobial and detoxifying particles for use in applications such as, but not limited to, nonwoven webs, paper, textiles, absorbent articles, healthcare products, paints, filter materials, powder coatings, clear coatings, molded plastic articles, binders for fibrous materials, and the like. The particles can be charged with halogen before or after incorporation into the application medium. The particles can contain blends of meta-aramid with other polymers such as, but not limited to, cellulose, cellulose acetate, polyurethane, and the like. The particles will be effective at inactivation of pathogenic and odor-causing microorganisms and toxic chemical agents. The particles, which contain N-halamine units, have unexpected resistance to ultraviolet light degradation. | 3 |
This application is a continuation-in-part of application Ser. No. 08/606,219, now U.S. Pat. No. 5,786,642, dated Jul. 28, 1998, filed Mar. 7, 1996, which is a continuation-in-part of application Ser. No. 08/328,574, filed Oct. 24, 1994, now U.S. Pat. No. 5,500,561 dated Mar. 19, 1996, which was a continuation of application Ser. No. 08/129,375, filed Sep. 30, 1993, now U.S. Pat. No. 5,363,333 dated Nov. 8, 1994, which is a continuation of application Ser. No. 07/944,796, filed Sep. 14, 1992, now abandoned which is a continuation of application Ser. No. 07/638,637, filed Jan. 8, 1991, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to improved cogeneration systems.
Cogeneration systems are capable of producing useful electrical and thermal energy output from a variety of fuel sources. By utilizing both types energy outputs, such systems characteristically achieve higher fuel efficiency. Currently small cogeneration systems are not cost effective because they tend to be capital intensive relative to the energy saving achieved. Their poor economy is a result of conventional system practice that attempts to size these units for peak capacity requirements, resulting in poor capacity factor relative to the load served. In summary, they would prove more cost effective if they could be sized for average electric and thermal power needs.
OBJECTS OF THE INVENTION
An object of the present invention is to permit hardware downsizing while maintaining or improving service thereby enhancing pay-back value.
A further object is to add more application flexibility by permitting the use of more than one power source. For example, public utility grid power, cogenerated power or on-site photovoltaic power can be used together without expensive power conditioning.
Another object is to reduce the control complexity of the cogenerator system.
Yet another object of this invention is to render the cogenerator to be sized for the average power needs for up to a 5 to 1 reduction in effective generator sizing as compared to peak power sizing. Standby losses are reduced thereby contributing to higher electrical efficiency which also contributes to further downsizing. In this way, the present invention contributes to the practicality of smaller sized cogenerators which broadens the range of applicability to single family housing and other smaller building spaces.
Another object of this invention is to create practical small cogeneration systems based on the use of internal combustion engine driven generators, fuel cell generation of electricity and heat, and thermophotovoltaic (TPV) cogeneration systems.
Another object of this invention is the configuration of an emergency power source for single family housing use with exceptional quietness, fuel efficiency and small size.
SUMMARY OF THE INVENTION
In keeping with theses objects and others which may become apparent the power sharing modular DC cogeneration system of the present invention includes a DC power system capable of receiving AC electrical power and DC electrical power from separate first and second sources simultaneously. The DC power system delivers DC electrical power to an output for use by a load requiring DC power.
The DC power system includes a converter to convert AC electrical power to DC electrical power and a power sharing control means to control and distribute the DC electrical power to an output.
The first source of DC electrical power includes a storage battery, which provides standby DC electrical power to the DC power system. It also includes a power sharing means, which maintains the storage battery fully charged for use at peak loads, when the DC output electrical power is insufficient to meet the DC load.
The second source of DC electrical power is a cogenerator such as a fuel cell, a thermophotovoltaic generator or an internal combustion engine and an alternator for generating and delivering DC electrical power to the power sharing means, while producing and delivering waste heat for use of an external load requiring this heat.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can best be understood in conjunction with the accompanying drawings, in which:
FIG. 1 is a block diagram of an engine driven cogeneration system;
FIG. 2 is a block diagram of a fuel cell driven cogeneration system;
FIG. 3 is a block diagram of a thermophotovoltaic (TPV) driven cogeneration system;
FIG. 4 is a block diagram of DC Power System Module; and
FIG. 5 is a block diagram of small emergency power source.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a cogeneration system using an engine driven generator. As opposed to the well established large capacity natural gas or liquid fueled diesel engine or gas turbine driven cogeneration systems, the present invention depicts a system sized for a typical household. Although the engine 4 may be an external combustion Stirling engine, a more typical type would be an internal combustion engine using a diesel cycle or spark ignition. Engine 4 drives a DC generator 3 or an alternator with built-in rectifying diodes, such as is common practice in automotive applications to convert the generated AC to DC right at the source. One or more thermal enclosures 5 capture the heat from the exhaust and cooling jacket of the engine and couple it to a heat exchanger 6, which can convey the thermal energy to do useful work. In some configurations, even the heat of the generator 3 is captured.
In the illustration of FIG. 1, the heat exchanger 6 is a liquid-to-liquid type which is used to heat domestic water in tank 7. Other uses might be space heating or cooling via a heat driven absorption air conditioner. The DC electrical energy from generator 3 is input to the DC power system module 1, which then powers the DC loads. Some examples of household DC loads that are presently available include lighting using DC electronic fluorescent ballasts, water pumps, refrigerators and freezers, entertainment equipment, personal computers, electric ranges and microwave ovens.
FIG. 4 shows a block diagram of DC power system module 1. This includes an AC grid connected input, a storage battery 25 and a DC Electronic Control Unit 20. Power sharing is accomplished via three major sources, grid supplied AC power, storage battery 25 and DC power input (which in this case is an engine driven DC generator 3). The grid supplied AC power is converted to DC power in block 21 which typically contains a bridge rectifier and filter capacitor. This is fed to a DC to DC converter 22 which is of a high efficiency switching mode topology with typical frequencies of 20 to 500 kHz to reduce the voltage to a nominal 26 volts DC, which is managed by the control and distribution block 23. The external DC input is conditioned by block 24 which includes transient suppression and is then input to block 23.
The storage battery 25 is either charged (using grid supplied AC or external DC input as a power source) by block 23 or it feeds power to block 23 as needed. In a cogeneration mode with the grid power not in use, the external DC input (i.e., the DC generator 3) supplies average power to the load at the DC output terminals, but if the load exceeds the capability of this source during a peak demand, block 23 will draw the required current from battery 25 to make up the deficit. The battery 25 is then recharged during low demand periods.
The features and advantages of the present invention compensate for the most significant limitations of previous embodiments of engine driven cogenerators.
First, the high or higher efficiency DC loads reduce the magnitude of the electrical load requirements.
Second, the managed storage (i.e. the battery) eliminates the need to over-size the cogenerator to meet the demand peaks (such as motor starting), since such batteries are capable of delivering very high peak currents. This has the very positive effect of reducing both the size of the engine and generator section of the cogenerator while still supporting the effective load requirements of a given application. Similarly, the increased system duty cycle on-time influenced by the present invention significantly reduces the number of starts and stops normally associated with the requirements of small scale systems. This improves the reliability of the engine subsystem and increases its effectiveness.
Further, the smaller hardware size permitted by the present invention affords greater packaging flexibility; this is a factor advancing modularity for lower production cost and easier and less costly installation.
If rendered more cost effective, fuel cells offer an attractive balance of electric and thermal generation. First introduced in the 1950's, the fuel cell is capable of uniquely high electrical conversion efficiencies (40% to 50%) over a wide range of load conditions. It is capable of converting the energy of fuel after reforming (to free the hydrogen bond from its molecular hydrocarbon bonds) directly into electrical energy. Thus, the usual steps and losses involved in conversion of fuel into heat and subsequently into mechanical energy and finally electrical energy are avoided.
Fuel cells are not Carnot-cycle limited. First generation fuel cells using phosphoric acid electrolyte (the most developed) operate with cell temperatures of 205 degrees C. (400 degrees F.) suitable for all domestic applications. It is possible to use them with a broad range of liquid and gaseous fuels, including coal derived gasses.
Fuel cells have the ability to convert domestic fuels with negligible environmental impact. Air emissions for key pollutants (SO 2 , NO 2 , and particulates) range from negligible to undetectable with gas or distillate fuels. Because of their high total energy conversion efficiency in cogeneration applications (80 to 85%), fuel cells produce lower levels of greenhouse gas pollutants such as carbon dioxide. The fuel processor, or reformer, supplies fuel of the proper composition and purity to the fuel cell stack, consequently transforming a hydrocarbon fuel into hydrogen and fuel byproducts. On going research to develop high-temperature fuel cells facilitate the reforming reaction to take place in the anode, thus eliminating the need for a separate fuel processor.
FIG. 2 shows the block diagram of a fuel cell cogeneration system of this invention. Hydrocarbon fuel is preprocessed in reformer 11 and fed with air (the oxygen source) to fuel cell 10. Thermal enclosure 12 couples the thermal energy generated with heat exchanger 6 which is shown in this illustration as heating water in tank 7.
The electrical output of the fuel cell is connected to the DC power system module 1 which is essentially as described above for the engine driven example. Therefore, power sharing between grid supplied AC power, storage battery power supplying peak loads, and fuel cell supplied DC power is controlled to supply DC loads 2.
Although fuel cells are capable of fast electrical load response and do maintain efficient operation under part load, the main advantages of this configuration are the down-sizing of the fuel cell, the efficient DC loads further supporting down-sizing and the elimination of the need for a power inverter to convert the intrinsic DC fuel cell output to AC for more typical AC loads. This down-sizing significantly reduces capital intensity of the installation since a limited amount of battery storage is a very cost effective alternative. Thus a cogeneration system for a household (or a modular package to provide part of a larger load) can be configured with no major moving parts to wear out or produce noise.
In the thermophotovoltaic (TPV) generator, combustion energy can be converted, with the proper emitter, into nearly monochromatic light and into heat. The light is converted into DC electric power with a photovoltaic collector at much higher efficiency than is possible, for example, with a broadband source like the sun.
The concept suggests a relatively straightforward way of deriving both electricity and high quality thermal energy from a single system and fuel source. Like the fuel cell, it also promises to have few, if any, moving parts.
The system combustor operates through a light producing fiber matrix emitter exposed to the mixture of fuel gas and air. At the outer surface both luminous energy and convective heat are simultaneously produced. The fiber matrix emitter is held in proximity to a photovoltaic (PV) cell array such that optimal radiant energy is collected.
Promising new developments suggest that radiant fluxes greater than one equivalent sun with a narrow optical bandwidth equivalent to, or slightly greater than, the bandgap of the photovoltaic (PV) collector is achievable. This suggests photovoltaic (PV) energy collecting economies are much more attractive than the current cost of $5 per watt. Research and development work at the Quantum Group in San Diego, Calif. suggests that it is possible to derive many equivalent suns of luminous energy from such a device with a practical fiber matrix emitter. This would significantly enhance lumen-to-power efficiency.
Not all of the characteristics of the thermophotovoltaics (TPV) are attractive, however. One limitation is that the ability to modulate or throttle the electrical output is lacking. With a narrow range of efficient operation, it must be operated in either an ON or OFF condition, rendering it ineffective under part load conditions.
Still another limitation of the current state of the art is the low electrical fuel efficiency of thermophotovoltaic (TPV) generator. However, a practical embodiment of a thermophotovoltaic (TPV) cogeneration system is shown in FIG. 3. The matrix/combustor 15 is fed fuel and air. The luminous radiant energy is converted to DC electrical power by the photovoltaic (PV) array 16. A thermal enclosure 17 couples the thermal load via heat exchanger 6 with the illustrated water heated application of tank 7. The photovoltaic (PV) electricity generated is coupled to DC power system module 1 for load sharing with grid supplied AC and peak demand supplied by a storage battery. The DC output is fed to DC loads 2.
In this embodiment, the thermophotovoltaic (TPV) generator is made practical because it can be sized for the average power requirements permitting it to function in the steady-state mode. The other efficiency factors mentioned for other cogeneration sources above also apply thereby contributing major cost reductions by further down-sizing the thermophotovolaic (TPV) unit.
FIG. 5 shows a configuration for a small emergency power generator for typical household use. A small gasoline engine 4 drives a DC generator 3 (or alternator with integral diodes) which is electrically coupled to the DC electronic control unit 20 previously described. A storage battery 25 is used to supply demand peaks so that the generator 3 and engine 4 are sized for average power demand.
Since a typical present day household may not have any DC loads 2, a DC to AC inverter 26 is included to supply typical household AC loads 27. An inverter 26 can be designed to handle large overloads or peaks at little additional cost; it is therefore capable of this peak load as supplied by peak power from the storage battery through control block 20. Such an emergency system can be stored much like the presently available units for the same purpose, and it can then be retrieved and started as needed.
The main advantages of this embodiment is that the battery supplied peak capability permits the use of a much smaller engine/generator combination to operate a larger portion (or all) of the appliances and lights of an entire household. Size, weight and noise are reduced while efficiency (i.e., low fuel use) is greatly enhanced.
Besides usability as an emergency back-up source, this same system as configured in FIG. 5 can be integrated as an uninterruptable power system with a continuous utility connection. The grid connected AC power keeps the battery charged and ready for uninterruptable back-up should there be a power outage. If the outage lasts past a predetermined period, or alternatively if the battery charge should fall below a predetermined level, an electrical starter 28 on engine 4 is automatically engaged to start it, thereby operating the emergency generator 3.
Other modifications may be made to the present invention without departing from the scope of the invention, as noted in the appended claims. | A DC power system receives AC electrical power and DC electrical power from separate first and second sources simultaneously. The DC power system delivers DC electrical power to an output for use by a load requiring DC power. The DC power system includes a converter to convert AC electrical power to DC electrical power and a power sharing control device to control and distribute the DC electrical power to an output. The first source of DC electrical power includes a storage battery, which provides standby DC electrical power to the DC power system. It also includes a power sharing device, which maintains the storage battery fully charged for use at peak loads, when the DC output electrical power is insufficient to meet the DC load. The second source of DC electrical power is a cogenerator such as a fuel cell, a thermo photovoltaic generator or an internal combustion engine and an alternator for generating and delivering DC electrical power to the power sharing device, while producing and delivering waste heat for use of an external load requiring this heat. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a CONTINUATION application of prior application U.S. Ser. No. 10/600,853 filed Jun. 20, 2003 now U.S. Pat. No. 7,400,958, which claimed priority to German Patent Application No DE 102 31 364.4 filed Jul. 11, 2002, all of which are incorporated herein by reference in their entirety.
BACKGROUND INFORMATION
The present invention is based on a system for triggering restraining means.
SUMMARY OF THE INVENTION
The system according to the present invention for triggering restraining means has the advantage that not only data from at least one impact sensor are incorporated in the triggering algorithm, but a pedestrian-impact sensor is taken into account as well. This provides the benefit of improving the detection of the impact location and the impact severity and minimizing the danger of a faulty triggering, that is, a misuse. This is because, in particular, a pedestrian-sensor system in the form of a pedestrian-impact sensor is usually located across a large area on the wheels of the vehicle. Conventional impact sensors, on the other hand, are mostly only utilized as up-front sensors, as side-impact sensors, or are located in the central control unit only at particular locations in the vehicle. In this case, the crash type, i.e., the impact location, can therefore only be ascertained via vectorial measurements. In contrast, the system according to the present invention overall improves the triggering of restraining means, such as airbags and belt tighteners.
It is particularly advantageous that the processor determines the crash type and crash severity for the triggering of the restraining means from the linking of the signals from the pedestrian-impact sensor and the impact sensor. In this way, it may be determined which restraining means are to be used and in which way. Especially the type is determined by the time characteristic of the restraining force to be exerted on the passengers inside the vehicle for their protection. If a hard crash is involved, the restraining force must likewise be exerted on the passengers in a correspondingly rapid manner. If only a soft crash has occurred, the power characteristic of an airbag, for example, need not be quite as forceful.
Furthermore, it is advantageous that, in the triggering of restraining means, the processor additionally considers signals from passenger sensors and/or pre-crash sensors. This makes it possible to use only those restraining means that do indeed protect passengers, and not only an empty seat, or which prevent, or at least considerably soften, a use of restraining means in the case of a dangerous seating position of the passenger. Signals from a pre-crash sensor allow, in particular, the timely triggering of restraining means and the use of so-called reversible restraining means, such as reversible belt tighteners or also a pop-up bumper. Furthermore, it is advantageous that the at least one pedestrian-impact sensor may be located in the front and/or in the rear bumper. In the case of frontal or offset crashes, this allows the impact location to be detected with a very precise local resolution since such a pedestrian-impact sensor usually extends over the entire width of the bumper, or at least over a substantial part of this bumper. Moreover, it is also possible for the pedestrian-impact sensor to be located across a large surface on the sides of the vehicle, in the trim molding, for instance. For side crashes, too, this allows a locally precise, resolved large-area detection of the impact location in the front and in the rear region.
It is also advantageous that the at least one impact sensor is embodied in the control device and/or as peripheral sensor, such as an up-front sensor or a side-impact sensor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a block diagram of the system according to the present invention.
FIG. 2 shows an additional block diagram of the system according to the present invention.
DETAILED DESCRIPTION
Currently, a great number of concepts exists with respect to protecting pedestrians, both in the field of sensing and in actuator technology. In most cases, it is bumper sensors that are proposed to detect a pedestrian impact. Force sensors or deformation sensors extending across the entire width of the vehicle in the bumper are used in this connection. Examples of such force sensors are piezofoils, strain gauges, optical sensors or sensors of composite. Among the deformation sensors are light guides or simple switches. In some cases, a plurality of sensors are used to detect the impact location. For the actual protection, airbag systems are essentially integrated in the engine compartment, or otherwise the engine hood is raised in order to counteract the impact of the person involved in the crash.
Airbag control devices which include an acceleration sensor within the control device and additional remote sensors, such as upfront sensors or peripheral sensors as well, if appropriate, already provide excellent triggering times in the event of a crash. According to the present invention, it is provided to improve the detection of the impact location and the impact severity by additionally utilizing the signal from the pedestrian sensory system for the triggering of the restraining means. This additionally permits higher redundancy or plausibility for the use of these restraining means.
The essence of the present invention is generally the processing of data from the pedestrian sensory system in the central control device for the triggering of restraining means. For this purpose, it is also possible to consider other control devices, such as the control devices for the passenger compartment sensing, in addition to the central airbag control device. The advantage in this case is that the pedestrian sensory system usually extends over the entire front region, so that the correct detection of the crash impact, that is, whether an offset crash is involved or possibly a frontal crash, may immediately be derived in a selective manner. Specifically, the crash type can be determined in a more unequivocal way. An additional advantage is the more conclusive detection of the crash severity. Corresponding data regarding the deformation of the vehicle in this region, as a function of the speed, will then result when evaluating the sensor signal. On that basis, the crash severity is able to be determined more clearly next to the acceleration signal, thus providing further information about the crash characteristic. This method may be used for sensing a side crash as well.
The data thus obtained may be considered in the airbag algorithm in a corresponding manner and significantly contributes to the triggering strategy. Furthermore, this signal is used as a plausibility signal in the area of so-called misuse, i.e., the faulty triggering event. If the algorithm detects a frontal impact, the pedestrian-protection sensors must sense an impact too. In the event of a truck underride, this may provide a significant time advantage since the bumper makes contact first in such a case, before the central control device detects an adequate signal. Thus, an improved robustness compared to acceleration sensors, such as an upfront sensor system and a central control device, is obtained. When using a rear sensory system in the bumper, this information may provide analogous data in the case of a rear crash as well.
FIG. 1 shows a block diagram of the system according to the present invention. Via a line 2 , an impact sensor 1 is connected to a control device 3 in which a processor is located for evaluating the sensor signals. Via a second data input, control device 3 receives signals from a pedestrian-impact sensor 4 , by way of a line 5 . Control device 3 is connected to restraining means 6 via a data output.
Here, only one impact sensor 1 is shown by way of example. It is possible that more than this one impact sensor 1 is used; specifically, it is possible for impact sensor 1 to be located in the control device itself. Alternatively, the impact sensor may be provided peripherally, either in addition or instead, i.e., either as upfront sensor under the engine hood, or as side-impact sensor in the A, B, or C-column or the rocker panel or the door, or in a side section itself. Especially an acceleration sensor may be used as impact sensor. As an alternative or in addition, it is possible to employ deformation sensors as well. Piezo sensors or optical sensors are among such deformation sensors, or also indirect deformation sensors, such as temperature or pressure sensors which react to an adiabatic pressure or temperature increase caused by an impact.
Line 2 may in this case be embodied as a two-wire line which allows merely the undirectional transmission of data, from impact sensor 1 to control device 3 . In the process, using this line, impact sensor 1 is able to be provided with a d.c. voltage in an advantageous manner, from control device 3 to impact sensor 1 . This d.c. current is then modulated by impact sensor 1 . However, it is also possible that voltage pulses are modulated and that the energy supply is realized separately from transmission line 2 . A bidirectional transmission between impact sensor 1 and control device 3 is possible as well. Furthermore, a bus line between impact sensor 1 and control device 3 may also be used, in which case both include controllers for bus communication. More than one impact sensor may be connected to this bus as well. The same holds for line 5 which connects pedestrian-impact sensor 4 to control device 3 . Lines 2 and 5 are electrical lines in this case. However, as an alternative, they may also be embodied as optical lines or radio transmission paths.
To be used as impact sensor 1 , in particular, is an acceleration sensor, which in this case may be a micromechanical sensor. Alternatively, it is also possible to embody it as a switch or as some other spring-mass system. Pedestrian-impact sensor 4 may be a piezo-foil, strain gauge, optical sensor or a sensor made of composite, as represented above. It is also possible to use conductive foamed plastic. As represented earlier, pedestrian-impact sensors 4 , of which only one is shown here by way of example, although more than one may be used as well, are preferably located in the front bumper. Alternatively, or additionally, it is also possible to locate such impact sensors in the rear bumper or the sides of the vehicle, for instance in the trim molding. Control device 3 , by including a processor such as a micro-controller, is provided with means for evaluating the signals. Control device 3 then triggers restraining means 6 in a triggering algorithm as a function of the evaluation of these sensor signals. Restraining means 6 may here also be connected to control device 3 via a bus or via two-wire lines, as already mentioned. Restraining means 6 are usually airbags or belt tighteners, which may also be triggered in stages. Thus, such restraining means may be used, in particular, adaptively, i.e., as a function of the crash severity and the passenger to be protected. Specifically, it is the weight of the passenger that determines which restraining means are used and in which manner, and whether or not restraining means are to be employed.
Control device 3 then uses both signals, i.e., that from impact sensor 1 and pedestrian-impact sensor 4 , to calculate the triggering algorithm. Only when both indicate an impact will restraining means 6 be triggered. Furthermore, the signals from sensors 1 and 4 allow a better determination of the impact location, since especially pedestrian-impact sensor 4 extends across the entire front of the vehicle. In addition, as just shown, the crash severity may be determined in a more optimal manner.
FIG. 2 shows an additional block diagram of the device according to the present invention. Connected to control device 3 in this case are pedestrian-impact sensor 4 , an acceleration sensor 7 having sensitivity in, and transversely to, the driving direction, and additional sensors 8 . The additional sensors 8 could be side-impact sensors and, in particular, passenger sensors and also pre-crash sensors. Control device 3 processes these data in the trigger algorithm in their entirety, in order to then trigger appropriate restraining means 10 via logic 9 . Especially ultrasound sensors and/or video sensors and/or radar sensors may be used as precrash sensors. Additional data, such as communication between vehicles, may be utilized in this context as well. | A system for triggering restraining means which has at least one impact sensor and at least one pedestrian-impact sensor, signals being transmitted from these sensors to a processor which is configured such that the processor triggers the restraining means as a function of a linkage of the signals. | 1 |
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