The present disclosure relates generally to circuit protection in communications systems; more particularly, the present disclosure relates to a circuit protection block, such as can be used in conjunction with a small form factor circuit protection device.
Telecommunications systems generally include connection and disconnection systems, through which various types of telecommunications equipment are interconnected. Such systems generally require electrical protection, such as to prevent overvoltage and overcurrent events from damaging equipment, as can occur in the case of lightning strikes, power surges, or other electrical events. Various types of gas tube and solid state overvoltage protection components exist and are used in these telecommunications systems.
In large telecommunications systems, protection blocks are used to ensure that overvoltage or overcurrent events do not damage telecommunications circuits. These protection blocks receive individual protection elements, which plug into the block to protect individual circuits. Existing protection devices include 5-pin voltage protection devices that include solid state or gas tube overvoltage protection for telecommunications circuitry. These existing devices are inserted into a 5-pin protection block in a 100-element array, resulting in a protection block that is approximately 7.9 inches by approximately 5.8 inches in size (and can be of a variety of depths). This dimension is known for use in a protection block known as a “307 block”, which is used in telecommunications cabinets and other arrangements for mounting purposes. When used in existing telecommunications systems, a large number of these blocks are used, to protect a large number of signal lines.
In certain systems, a piece of equipment used for connection of telecommunications systems is referred to herein as a connection block, sometimes referred to as a “Krone-style connector block”, such as those manufactured by ADC GmbH, formerly Krone GmbH. These connection blocks provide an array of punch-down connection locations useable for individual wire pairs, and include circuit protection locations in a single linear array. However, because Krone-style connector blocks include circuit protection locations along the array of punch-down connection locations, they are not space-efficient circuit protection devices for large signal arrays in large, high density telecommunications systems.
The present disclosure relates generally to protection block useable with small form-factor overvoltage protection plugs. The protection block includes a dense, two dimensional array of circuit protection locations, while remaining within dimensions reserved for protection blocks in a telecommunications system.
According to a first aspect, a protection block is disclosed. The protection block includes a rectangular housing having a front, a rear, and top, bottom, left, and right sides. The protection block also includes a plurality of sockets arranged in a two-dimensional array in the front of the housing, each of the plurality of sockets associated with two pairs of opposed, normally open contacts. Each of the plurality of sockets is arranged to receive an overvoltage protection plug that separately connects each of the two pairs of contacts. The protection block also includes a plurality of electrical connections in a second discrete region of the block separate from the first discrete region, the plurality of electrical connections electrically connected to the contacts. The protection block also includes a grounding bar associated with one or more of the sockets and positioned for electrical connection to a ground connection of an overvoltage protection plug when inserted into a socket.
According to a second aspect, a method of protecting a telecommunications circuit is disclosed. The method includes mounting a protection block in a telecommunications system, the protection block including a plurality of sockets in a first discrete region and arranged in a two-dimensional array, each of the plurality of sockets associated with two pairs of normally open contacts, wherein each of the plurality of sockets is arranged to receive an overvoltage protection plug that separately connects each of the two pairs of contacts. The method also includes electrically connecting telecommunications wires to pins of the protection block arranged in a second discrete region separate from the first discrete region and associated with one of the plurality of sockets. The method further includes inserting an overvoltage protection plug into the socket, thereby connecting the normally open contacts and activating and protecting a circuit associated with the socket and the telecommunications wires.
According to a third aspect, a protection block is disclosed. The protection block includes a rectangular housing formed from a base and a cover and having a front, a rear, and top, bottom, left, and right sides. The protection block also includes a plurality of sockets arranged in a two-dimensional array in the front of the housing, where each of the plurality of sockets is associated with two opposed pairs of normally open contacts, and each of the plurality of sockets is arranged to receive an overvoltage protection plug that separately connects each of the pairs of contacts. The protection block also includes a plurality of pins extending from the rear of the housing, each of the plurality of pins electrically connecting to a contact. The protection block further includes a plurality of grounding bars, each of the plurality of grounding bars associated with one or more of the sockets and positioned for electrical connection to a ground connection of an overvoltage protection plug when the overvoltage protection plug is inserted into one of the plurality of sockets. The pins associated with the two opposed pairs of normally open contacts of a socket are electrically connected to differential signal wires of a telecommunications circuit.
Referring to
The protection block 10 includes a housing 12 formed from a cover 14 and a base 16. The housing 12 is generally rectangular, having a top side 18, a bottom side 20, left and right sides 22, 24, respectively, and a front 26 and rear 28. The housing is preferably sized to fit into a protection block mounting structure (not shown). In the embodiment shown, the housing 12 is approximately 7.9 inches by 5.8 inches in size. The overall depth of the protection block 10 can vary within the limitations set by the enclosure in which the block is placed; in the embodiment shown, the block 10 is approximately 2.17 inches deep. These dimensions can vary in other embodiments of the present disclosure.
The cover 14 is connected to the base 16 by a plurality of connectors, shown as screws 15, which are inserted through the cover 14 and base 16 on the right side 24 to form the housing 12 from the two components. Additional screws 15′ can be inserted through the base 16 (as shown in
The housing 12 includes a plurality of sockets 30, each of which is arranged to accept an overvoltage protection plug 100. The sockets 30 are formed through the front side 26 of the cover 14, and allow access to contacts 32 mounted in the base 16 of the block. The sockets 30 are generally arranged in a first discrete region, in the embodiment shown taking the form of a two-dimensional array including linear rows extending from the left side 22 of the block 10 to the right side 24 of the block. In the embodiment shown, the protection block 10 accepts 200 overvoltage protection plugs 100, inserted into the sockets 30 through the cover 14. Additional sockets can be included in the system as well.
Each socket 30 is sized and shaped to at least partially receive a housing of an overvoltage protection plug 100 inserted into the socket, such as the plug described in conjunction with
The overvoltage protection plugs 100 received by the protection block 10 of the present disclosure can be any of a variety of small form factor protection plugs, such as could be inserted into a Krone-style connection block. One example of such an overvoltage protection plug is described below, in conjunction with
In certain embodiments, the overvoltage protection plug used in the protection block can include one or both of overvoltage and overcurrent protection capabilities. For example, the overvoltage protection plug can also include fuses connected between opposed pairs to ensure that the current does not exceed a threshold value. Other arrangements and protection schemes are possible as well.
The contacts 32 extend toward the cover 14 through the base 16 and are exposed at the front 26 through the sockets 30 in the cover for connection to the overvoltage protection plugs. The contacts 32 are arranged in opposed linear pairs, with two pairs of contacts per socket (i.e. a total of four contacts per socket). The pair of opposed contacts 32 are normally open, in that they are disconnected from each other in the absence of a device (e.g. an overvoltage protection plug 100) separately connecting each of the opposed pairs in the socket 30. In the embodiment shown, the contacts 32 do not extend through the cover, and remain within a periphery of the block 10 as defined by the housing 12.
When an overvoltage protection plug 100 is inserted into a socket 30, electrical contacts on the overvoltage protection plug 100 complete a circuit between the opposed contacts, allowing telecommunications signals to pass through the two completed circuits of the differential pair. The contacts 32 electrically connect to pins 33 which are arranged in a second region. In the embodiment shown, the contacts 32 connect to pins 33 on a rear 28 of the base 16. In use, the pins 33 are electrically connected to signal wires, such as by wire wrapping the signal wires to the posts. The signal wires can be bundled and lead away from the protection block 10.
The pins 33 are optionally sealed to the rear 28 of the base 16, alongside the signal wires, under a plastic or other non-conductive filling element. In such an embodiment, the filling element can be poured into the rear 28 of the base 16, which includes a perimeter portion 17 that extends beyond the length of the pins 33 to contain the filling element.
Preferably, the pins 33 and contacts 32 are unitary, and are inserted through the base for connection to signal wires and overvoltage protection plugs 100. However, in other embodiments, the pins 33 and contacts 32 can be electrically connected by wires, soldering, or other methods.
A grounding plate 36 is attached to the housing 12 by the screws 15 located along the right side 24 of the housing. The grounding plate 36 electrically connects to a plurality of grounding bolts 38 and a plurality of the grounding bars 34 (shown in
In the embodiment shown, the grounding bars 34 are connected to the grounding plate 36 at a press-fit connection locations, as described below in conjunction with
Referring now to
Portions of the cover 44 forming the openings 40 extend into the base 16 when the cover 14 is attached to the base. The portions of the cover 44 form three walls around each opening 40, forming an insertion portion for each socket 30. The side of the opening 40 that the portion 44 does not surround receives an extension of the grounding bar 34 for connection to the overvoltage protection plug 100. The portion of the cover 44, when the cover 14 is attached to the base 16, is inserted into the base, preferably causing any gel or liquid in the base to rise in level to cover components in the hollow cavity 42.
Referring now to
An interior portion 56 of the base 16 (i.e. which resides in the interior of the housing 12, as shown in
The surface of the base 16 forming the rear 28 of the housing 12 (as shown in
The contacts 32 are generally conductive (e.g. metallic or otherwise conductive), and are capable of making an electrical connection with corresponding contacts of an overvoltage protection plug when physical contact is made between conductive portions of each contact. In the embodiment shown, the contact 32 includes a pin 33 formed as a portion of the contact and used to electrically connect to signal lines on the rear 28 of the block 10. In such an embodiment, the contact 32 is inserted through the base 16 in the manner shown in
The grounding bar 34 includes a plurality of extension pairs 35 that insert into a portion of an overvoltage protection plug 100 to provide a common ground connection to the block 10 and plug 100. The extension pairs 35 are offset from the portion of the grounding bar 34 inserted into the slots 60 of the base 16, to align the extension pairs with a portion of the sockets 30 for insertion into overvoltage protection plugs 100 when such plugs are inserted into the sockets. In the embodiment shown, the ground bar includes 14 extension pairs 34, corresponding to one extension pair per socket 30. A flange 62 on one side of the ground bar 34 extends to the right side 24 of the protection block 10, and electrically connects to a grounding plate 36.
The grounding plate 36 is substantially planar, and includes extension pairs 64 that extend toward the front 18 of the block 10 when the grounding plate is installed on the right side 24 of the block. Each extension pair defines a slot through which the flange 62 of each grounding bar 34 is inserted. Insertion of the flange 62 through the slot in the extension pairs 64 of the grounding plate 36, through a press-fit connection, electrically connects each grounding bar 34 to the grounding plate. Bolts 38 passing through holes 66 in the grounding plate 36 electrically connect to the grounding plate as well, and provide a location for connecting a grounding wire to the protection block 10. Additional holes 68 in the grounding plate receive screws 15 used for attaching the grounding plate 26 to the housing 12 (as well as for connecting the cover 14 to the base 16 to form the housing).
Referring now to
Although the current disclosure discusses in detail the arrangement of overvoltage protection plugs with respect to a protection block or a specific size (the “307 block”), other sizes of blocks can be used as well with corresponding numbers of sockets for receiving overvoltage protection plugs. For example, the protection block can be used in locations (indoor, outdoor, entrance terminal, etc.) where other standardized-size blocks are used, to provide a different number of connection locations within these standard footprint protection block areas, as compared to existing 5-pin blocks. For example, in certain embodiments, the protection block can correspond to a connection block that is about 16.25 inches high, and of sufficient width to receive 100 groups of 5-pin terminals. This type of block, also called a “302-block” is available in a variety of specific models used for outside the plant applications (e.g. panel applications). Or, the connection block can be a “310-block”, which provides room for 100 protection locations in a footprint of approximately 9⅜ inches by approximately 4 inches by approximately 7 inches. In a further embodiment, the block can correspond to a “303 block” used to receive 100 5-pin connectors in a housing approximately 19.2 inches by approximately 4.29 inches. In other embodiments, the protection block can correspond to a smaller package useable at entrance terminals, such as can be found in the “ST265” or “ST260” sized blocks, which are configured to receive six five-pin connectors in a block approximately 6 inches by 3.2 inches by 2.72 inches, or 12-25 five-pin connectors in a block approximately 10 inches by approximately 3.836 inches by approximately 3.05 inches, respectively. In still other embodiments, the protection block can correspond to a middle-sized block arranged to receive 50-100 five pin connectors, useable for entrance terminals or other analogous applications, such as the “ST188” and “ST189” sized blocks. Further block sizes can be used as well, such as the “110ANA” block size used in indoor applications and which can be configured in 6, 10, and 25 5-pin socket capacities, and are sized at approximately 3.5 inches by approximately 4.1 inches by approximately 2.6 inches (6 socket), approximately 3.9 inches by approximately 4.5 inches by approximately2.6 inches (12 socket), or approximately 10 inches by approximately 3.9 inches by approximately 2.6 inches (25 socket). Other block sizes can be use as well to be configured to specific applications in a telecommunications enclosure, in various additional embodiments.
Through use of blocks arranged according to the present disclosure, the density of overvoltage protection plugs that can be inserted into a block is increased. This space savings is due, at least in part, to the smaller dimensions of the sockets used in the block, and the corresponding dimensions of the overvoltage protection plugs used in conjunction with the block. For example, in each of the example embodiments in which the size and arrangement of the protection block is altered, replacement of the 5-pin protection element socket with the sockets (and plugs) described herein allows increased density of connections in a similar sized protection block. Preferably, and as is possible in certain embodiments, replacement of the 5-pin protection element with the sockets and plugs described herein at least doubles the capacity of the protection block of a corresponding size, based on this improved density. In such embodiments, it is also possible that certain portions of the block remain unoccupied by sockets, allowing room within a standard-sized block to be used for other purposes, such as incorporation of circuitry, display information, or other elements. An example of such a configuration is highlighted in the 307 block size that is described above in conjunction with
Referring now to
The plug 100 includes a body 112 formed from a chassis 114 and a housing 116. The body 112 has a top 113, bottom 115, right and left sides 118, 120, respectively. The body 112 also defines an insertion side 122 and a handle side 124 at opposite sides along its length. The size of the body 112 is minimized, at least with respect to the dimensions from the top 113 to bottom 115 and right to left (sides 118 and 120, respectively). This maximizes the circuit density in which the plug can be located. In one possible embodiment, the body 112 is approximately 0.31 inches wide by approximately 0.49 inches tall by approximately 1.44 inches long.
In the embodiment shown, two conductive contacts 126, 128 extend through the body at the insertion side 122, and are positioned to make contact with and electrically connect to electrical contacts in a high contact density connection block, such as a Krone-style connection block. Example Krone-style blocks useable in conjunction with the plug 100 are disclosed in German Patent No. DE3728368 and German Patent Application No. DE10001553. Additional details are described in U.S. Pat. Nos. 7,147,412; 7,008,243; 5,494,461; 5,163,855; 5,033,974; and 4,871,330, the disclosures of which are hereby incorporated by reference in their entireties.
The chassis 114 and housing 116 interconnect to form the body 112 via a snap-fit arrangement, in which tabs 130 arranged on a portion of the chassis inserted into the housing fit within openings 132 in the housing. Other arrangements for interconnecting the chassis 114 and housing 116 are possible as well, such as use of an adhesive, fastener, or other structure. Additional details of the chassis and housing are discussed below in conjunction with
Referring now also to
The gas tube 136 is electrically connected to the conductive contacts 126, 128. In the embodiment shown, the conductive contacts 126, 128 can be electrically connected to the signal leads 138 of the gas tube via a soldered connection; however, solderless connection arrangements are possible as well.
The gas tube 36 also electrically connects to a grounding plate 42. The grounding plate 42 is held apart from the gas tube 36 by a portion of the chassis 14, which allows the grounding pin 40 of the gas tube 36 to slide through the chassis to a mounting position. A grounding opening 44 in the body 12 allows external access to the grounding plate, to allow electrical connection of the grounding plate to a ground bar, such as a grounding bar associated with a connection block.
A gel access opening 146 extends through the body 112 as well. The gel access opening 146 allows access to the interior volume 134 of the plug 100. A gel can be added into the interior volume 134 to environmentally protect components within the interior volume 134. The gel access opening 146 generally allows gel to be provided into the interior volume 134 to a predetermined volume, such as the predetermined fill level 141 shown in
Referring now to
The chassis 114 includes slots 152 extending through the chassis 114 from the interior portion 150 toward left and right sides of the insertion portion 148. The slots 152 are sized to receive the conductive contacts 126, 128, which are exposed at the insertion portion 148 external to the body 112 while electrically connecting to the gas tube 134 within the interior volume 134. The insertion portion 148 also includes a central guide extension 149 that physically and electrically separates the conductive contacts 126, 128.
The chassis also includes a central pin receiving slot 54 normal to the slots 152 and arranged to accept insertion of the grounding pin 140 of the gas tube 136, for connection to the grounding plate 142. Tabs 156 on a top side of the chassis 114 define a mounting location for the grounding plate, and retain the grounding plate 42 in place when the overvoltage protection plug 100 is assembled. In the embodiment shown, the chassis 114 includes the gel access opening 146 located below the insertion portion 148, as previously described.
Referring now to
The housing 116 includes tab receiving openings 132 near the opening 135 that are configured to receive the tabs 130 of the chassis to form a snap-fit connection. The openings 132 are generally numbered and positioned in a manner complementary to the tabs 130, such that each tab has a corresponding opening.
The housing 116 defines a handle 160 shaped to be manually gripped for insertion and removal of the overvoltage protection plug 110 from a socket, connection block, or other insertion location. The handle 160 includes a plurality of ridges 161 to assist with manual gripping of the plug 100. The handle 160 can also be shaped to accept use of a punch down tool for insertion or removal of the plug 100. For example, the handle can include a hook-shaped portion for receiving a portion of such a tool. The punch down tool (not shown) can be used to insert or remove the overvoltage protection plug 100, due in part to the sizing and positioning of the handle 160 at the handle portion of the housing 116, extending rearwardly from the plug. As described above, an example punch down tool can be any of a variety of tools include a gripping portion (for example, a hook), such as a punch down tool distributed by ADC Krone GmbH. An example punch down tool is described in U.S. Pat. No. 4,434,542, the disclosure of which is hereby incorporated by reference in its entirety.
Referring now to
The gas tube 136 can be any of a variety of sizes. In various embodiments, the gas tube 134 is a gas discharge tube rated to meet electrical specifications of Underwriter's Laboratories, Telcordia, or another electrical safety specification appropriate to the region in which the plug 100 is used. Such gas discharge tubes can be any of a number of gas tubes manufactured by Boums or other gas discharge tube manufacturer. In the embodiment shown, the gas tube has a diameter of approximately 5 mm. However, other sizes of gas tubes may be used as well to ensure that the necessary electrical specifications are met for use of the plug 100.
Optionally, the gas tube 136 includes a melt element 162 along the length of the tube. The melt element operates to permanently connect the signal leads 138 to the grounding pin 140 if a prolonged overvoltage event is detected. In the case of such an event, the gas tube 136 is activated for a long period of time, causing the temperature of the gas tube to rise, melting the melt element and causing a short circuit between the signal leads 138 and the grounding pin 138.
Now referring to
Referring now to the disclosure of
A grounding plate 142 is electrically connected to the grounding pin 140 of the gas tube 136. The grounding plate is installed over the grounding pin, optionally such that a portion of the chassis 114 resides between the grounding plate 142 and the gas tube 136.
The interior portion 150 of the chassis 114, including the installed gas tube 136, grounding plate 142, and portions of the conductive contacts 126, 128, is inserted into the housing 116 to form a snap-fit connection, forming the overvoltage protection plug 100. The interior volume of the formed plug 100 can be filled with a gel, such as by inserting the gel through a gel access opening in the body 112 of the plug. The gel surrounds the grounding plate 142, conductive contacts 126, 128, and gas tube 136, to environmentally protect the electrical components from moisture or other harmful external conditions.
In operation, the overvoltage protection plug 100 is inserted into a connection block, thereby connecting two sets of contacts for a differential signal pair routed through the connection block. The overvoltage protection plug 100 detects overvoltage events, representing instances in which the voltage difference across the differential pair exceeds an acceptable, preset threshold value. When the voltage difference exceeds this threshold value (as determined by the specific voltage characteristics of the selected gas tube), one or both of the signal leads of the gas tube are shorted to the grounding pin of the gas tube, as described above in conjunction with
One example of a similar overvoltage protection plug that has analogous functionality is described in U.S. patent application Ser. No. 11/712,234, filed Feb. 28, 2007, and entitled “Overvoltage Protection Plug”, the entire disclosure of which is hereby incorporated by reference in its entirety.
Although certain particular methods of construction and operation of an overvoltage protection plug are described herein, other methods of construction and operation are possible as well. Furthermore, the various steps described to construct an overvoltage protection plug are not required to be performed in a specific order, and no order is imputed by this description.
Furthermore, it is noted that, although in the foregoing description of the overvoltage protection plug 100 terms such as, “top”, “bottom”, and “side” and words related thereto are used for ease of description and illustration, no restriction is intended by use of such terms. The plug 100 can be positioned in any orientation.
The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
This application claims priority to U.S. Provisional Patent Application No. 61/048,091, filed Apr. 25, 2008, as well as U.S. Provisional Patent Application No. 61/081,919, filed Jul. 18, 2008. The disclosure of each of these applications is hereby incorporated by reference in its entirety.
Number | Date | Country | |
---|---|---|---|
61048091 | Apr 2008 | US | |
61081919 | Jul 2008 | US |