Title of Invention

"A TERMINAL BLOCK AND METHOD OF ASSEMBLING THE SAME"

Abstract

The present invention relates to protective relays for providing protective control to electncd distribution systems.A terminal block comprising:a plurality of separable, modular tiers, each tier having a first end provided with terminal connections for electrical connection to an electrical distribution system, and a second end opposite the first end, the second end provided with a set of contacts for electrical connection to signal terminals of a module in a protective relay,wherein each of the plurality of tiers has a different length between the first and second surfaces from the other tiers

Full Text

TERMINAL BLOCK FOR A PROTECTIVE RELAY Field of the Invention The present invention relates to protective relays for providing protective control to electncd distribution systems. More paricularly, the present invention relates :o lerminal connections which connect the rolay circuitry to the electrical distribution systera. Background of the Invention Protective relays for electrical distribution : ystems provide numerous functions relating to protective control, including ever-current and under-voltage protection, and ars essential elements of any electr.cal distribution system. Protective relays include internal processing circuitry which monitors the portion of the electrical distribution system with which it is associated (e.g., a feeder line) and provide protection and control functions as necessary. Conventional protective relays include digital circuitry in which logic functions determine the operation of the relay, such that the relay wil. operate to provide protective control under certain specified, potentially hazardous conditions. Protective relays must be operativeiy connected to the electrical distribution systeri to be monitored. Such connecu'ons between the internal circuitry of the protective relay and the electrical distribution system are conventionally established by terminal blocs. The terminal blocks, when ths protective relay is associated with a current transformer, enable the relay to short-circuit the terminals of the transformer. Conventional terminal blocks provide staggered connection terminals to improve user accessibility. However, due to the number of possible connection schemes between a protective relay and an electrical distribution system, staggered terminals may not provide adequate user acccssitility. Further, :he connection terminals of conventional terminal blocks, evf n if staggered, are typically fixed in configuratior.,- Ti.-rmir.a! blocks providing flexible mourning arrangements would be desirable, though conventional terminal blocks do not adequately provide such a capability. Further, many terminal blocks do not allow shorting capabilities to be configurable for multiple positions and in any location in the block. Summary of the Invention The present invention overcomes the aboue-noied deficiencies, and achieves other advantages, by providing for a protective relay terminal block configurable in a plurality of tiers, each tier being a different length, such that the relay connections associated with each tier are a different distance irom the protective relay to improve accessibility. An exemplary terminal block according to the present invention includes a plurality of sep;irabie, modular tiers. Each tier has a first end provided with terminal connections for electrical connection to an electrical distribution system. A second end, opposite the first end, is provided with a set of contacts for electrical connection to signal terminals of a module in a protective ready. Each tier has a different length between the first and second ends. Each tier can be provided with at least one dovetailed alignment element which allows the their to be slidably engaged with a dovetailed alignment element of an adjacent tier to engage adjacent tiers. According to another aspect of the preser.t invention, an exemplary protective relay includes relay processing circuitry for performing protection and control functions in an electrical distribution system, and at least one terminal block. Each terminal block has a plurality of separable tiers. Each tier has a first end provided with terminal .connections for electrical connection to the electrical distribution system, and a second end opposite the first end i ? provided with a set of contacts for electrical connection to the relay processing circuitry. Each of the plurality of tiers has a different length between the first and second ends. According to cither aspect of the present invention, an exemplary terminal block can optionally include shorting fingers electrically connected to each contact, each shorting linger configured so as to contact shorting finger associated with an adjacent contact when there is no module connected to the terminal, block. Each terminal connection can be implemented by a screw which attaches a contact to the terminal block at the first end of its associated tier. lEach contact preferably extends beyond 'he second end of its associated tier by a substantially uniform length. A terminal clock according to the present invention advantageously provides enhanced user accessibility as at least one result of tie variable number of modular tiers. Further, the lerminal block can be mountable :.n multiple orientations (e.g., left or right}, and can be configured, using appropriate snorting fingers, to provide shortinc; between any two adjacent terminal connections. Brief Description of the Accompanying Drawings The present invention can be understood more clearly upon reading the following Detailed Description of Preferred Embodiments in conjunction with the accompanying drawings, in which like reference intlicia designate like elements, and in which: FIG. 1 is a view of a relay connection interface showing the terminal connections for connecting the relay to an electrical distribution system; FIG. 2 is a profile view of a terminal block according to an embodiment of the present invention; FIGs. 3A-C are a top, side, and front view, respectively, of a contact suitable for use in the tenr.inal block of FIG. 2; FIGs. 4A-3 are side and front views, respectively, of a shorting finger suitable for use in the terminal block of FIG. 2; and FIGs. 5A-C are top, front, and cross-sectior al side views of a tier element suitable for use in the terminal block of FIG. 2. Detailed Description of PreferredJErnbodi meats FIG. 1 shows a relay connection interface 12 including terminal blocks 14 provided with terminal connections 16 for connect ;ng the relay to an electrical distribution system (not shown). The interface 12 would typically be provided on a surface of a relay housing. As shown in FIG. 1, ar.d as will be shown in more detail later, the terminal blocks 14 can have three tiers, or levels 14a-c, each tier being provided with terminal connections. Each tier has a different length, such that each row of terminal connections is located a differen: distance from the surface of the relay housing. By providing terminal connections at varying distances from the surface of the relay housing, the present invention increases user accessibility to the terminal connections. Further, as shown in FIG. 1, terminal blocks according to the C3 present invention can be mounted facing in multiple directions (e.g., either left or righ;). This aspect of the terminal block accordhg to the present invention provides additional moaning flexibility over conventional terminal blocks. FIG. 2 is a cross-sectional profile view of an exemplary terminal block according to th; present invention. The terminal block 14 in this example is comprised of three modular, separable tiers 14a, 14b, and 14c. It will be appreciated that, due to the modularity of the tiers, the number of tiers is easily varied. The construction of the tiers, and their assembly into the terminal block of FIG. 2, will be described in more detail below. Each tier includes a molded plastic portion 18, a contact 20, and a terminal connection screw 22. The terminal connection screw 22 screws into a mounting hole as shown in FIG. 2 and is mechanically and electrically in contact with the contact 20 at a first end. According to one exemplary embodiment, the terminal connection screw 22 provides a terminal connection capable of acc According to an aspect of the present indention, each terminal block can optionally be provided with shorting fingera 24. The. shorting fingers 24 are mechanically zmd electrically attached to an associated contact 20, and the shorting fm»ers of different contacts are shaped, mountei and configured so as to come into coctact with cne another when the; terminal block, is not connected to relay monitoriiig. anc. processing circuitry. The shorting ringers are particularly advantageous for use with modular relay circuitry, wherein each relay includes some variable number of modules which can be selectively mounted or removed to vary the functions of the relay. In operition, when a terminal block, is not associated with a module, the shorting fingers of adjacent contacts will be in contact with one another to automatically short circuit the adjacent contacts. Alternatively, when the terminal r block is connected to relay circuitry (e.g., by inserting or mounting a module onto the contacts 20j, the shorting fingers are separated by i, non-conductive element provided on the module to allow each contact 20 to be separately electrically connected to the relay processing circuitry. This function of the shorting fingers prevents the otherwise hazardous condition of "live" contacts, where one 3r more of the terminal screws 20 are electrically connected to the electrical distribution system, and where the contacts are no': connected to any relay circuitry. A second function of the shorting fingers i:; to allow shorting to occur between any two adjacent terminal connections on the block. To implement shorting between two desired temv.nal connections, shorting fingers are provided between appropriate adjacent signal contacts. FlGs. 3A-C show a top view, side view, and front view, respectively, of a contact for use in the terminal block of FIGs. 1-2. The contact includes a seat portion 30 at a first and which cooperates with a corresponding seat portion of a tier element to be shown and described later. As shown in FIG. 3C, the seat portion 30 includes an aperture 32 through which a connector such as a terminal connection screw can be inserted to mechanically connect the contact to the tier element. The contact also includes a contact portion 20 at the opposite end irom the seat portion which can be connected to the relay processing circuitry. It will be appreciated that in the example shown in FIGs. 3A-C, the contact portion 20 is configured to connect to a relay processing module, but that the contact portion can be modified as necessary to connect to virtually any type of relay processing circuitry. The contact of FIGs. 3A-C is shown as having a second aperture 34. Such an aperture can be used to attach a shorting finger 24 to the contact, as will be described later in more detail. The contact of FIGs. 3A-C includes two portions, a first of length /, and a second of lengih 12. As will be described below, the length /, is selected based on the length of the ti;r with which the contact will be associated, and the length /, is substantially constant such that the contacts 20 of an assembled terminal block extend a substantially uniform and predetermined distance from the terminal block body. For example, ^ three-tier terminal block according to an embodiment of the present invention can include three different types of contacts, having three different /, lengths, depending upon the tier in which the contact is to be mounted, but each having the same /, lengths. The contact of FIGs. 3A-C is preferably formed as a stamping, and p-eferabiy can withstand a current of approximately 500 Amps for approximately one second. The contact 20 can be made of brass or other suitable conductive material. FIGs. 4A-B show a side and rear view, respectively, of a shoning finger 24 according to the present invention. The shoning finger 24 includes an aperture 40 (FIG 4B) which can be aligned with the aperture of the seat portion 30 of an associated contact. The shorting finger can be attached to the contact by a rivet or other suitable means'. The shoning finger 24 is preferably made of a conductive material, such a* a BeCu alloy and, according to one example, has a thickness of approximately .016 inches. It will be appreciated that shoning fingers can be provided on all of the contacts, only a portion of i.he contacts, or none of the contacts in a terminal block, depending upon the particular application. FIGs. 5A-C show a top, front, and cross-sectional view, respectively, of a tier element 14 to be assembled with a plurality of contacts, such as is shown in FIGs. 3A-C, to form a tier section of a complete terminal b'ock, such as is shown in FIG. 2. As shown in FIG. 3 A, the tier element includes seat portions 50, which correspond to the seat oortions 30 of the contacts, for seating multiple contacts. The tier element also includes mounting portions 52, which are provided with mounting holes 54, which allow the terminal block to be mounted in a secure manner on the protective relay. The tier element further includes alignment elements 56 and dovetailed alignment elem.ents 58. Tae dovetailed alignment elements 58 are formed so as to be slidahly engageable with corresponding dovetail element"; of adjacent tier elements, and the alignment elements 56 facilitate alignment with corresponding alignment elements 01' adjacent tier elements. The. alignxnenrelenrems, as shown in FIG. 5Br can extend along substantially the entire front surface, and can include alignment notches N, which cooperate with corresponding alignment notches of alignment elements of neighboring tier elements, to facilitate proper assembly of a multiple tier terminal block. In FIG. 5C, which is a cross-sectional side view along line A-A in FIG. 5B, seat portion 50 at one end of the tier element, and contact cavity 60 at the other end of the tier element. An elongated cavity 62 is provided between seat portion 50 and contact cavity 60 to accommodate the contact element shown m FIGs. 3A-C. It will be appreciated that the tier element shown in FIGs. .5A-C is an end tier element, which include:; the elements 56 and 5S on only one side. In a multiple tier terminal block, middle tier elements would be provided with alignment elements and dovetailed alignment elements on each side of the tier element, A multiple tier terminal block according to trie invention can be assembled as follows. Tier elements having different lengths are fabricated of e.g., molded plastic. As shown and described above with respect to FIGs. 5A-C, each tier element can include a plurality of seat portions each having a first apenure for receiving a terminal connection screw. A number of electrically conductive contacts, such as are shown in FIGs. 3A-C, are inserted into the tier elements and .press-fit into the tier element to achieve the bent configuration shown in the figures, Each contact includes a seat portion which is mounted in the corresponding seat portion of a tier element, and each contact has a midsection length corresponding to ths length of the tier element. The contact elements are then secured to the tier element of corresponding length by inserting terminal connection screws through the apertures of the contact seat portions and the tier element seat portions. The contact elements can optionally be provided with shorting fingers, according to the particular relay application. Once a terminal block tier is formed, tiers (e.g., three) of different lengths are assembled by appropriately aligning the alignment elements on different length terminal block tiers, and slidablv engaging the dovetail alignment elements to form the terminal block of FIG. 2. The assembled terminal block can then be mounted, in one of multiple orientations (e.g., left or right, vertical or horizontal, etc.), on a protective relay and secure;! to the protective relay by mounting screws inserted into the mounting holes 54. The assembled and mounted terminal block can then be connected to an electrical distribution system via the terminal connection screws, and can be connected to relay processing circuitry via the relay contact portions. Because the tiers are separable and modular, the terminal block according to the present invention can include a variable number of tiers to enhance accessibility to the terminal connection screws. Thus, using tiers having 8 terminal connections each, terminal blocks can easily be assembled which provide 8,16, 24, etc. terminal connections. While th« foregoing descnption includes many details ,nd specificities, it will be unc.erstood thJ.t these are for illustrative purposes only and are not to be construed as iim.tations of the invention. Numerous modifications will be readily apparent which do not depart from the spirit and scope of the invention, as defined by the following claims and their legal equivalents. We Claim: 1. A terminal block (14), comprising: a plurality of separable, modular tiers (14a, b, c), each tier (14a, b, c) having a first end provided with terminal connections (22) for electrical connection to an electrical distribution system, and a second end opposite the first end, the second end provided with a set of contacts (20) for electrical connection to signal terminals of a module in a protective relay, wherein each of the plurality of tiers (14a, b, c) has a different length between the first and second surfaces from the other tiers (14a, b, c). 2. The terminal block (14) as claimed in claim 1, comprising shorting fingers (24) electrically connected to contacts (20) in different sets, each shorting finger (24) being configured so as to contact a shorting finger (24) associated with an adjacent contact (20) in a different set when there is no module connected to the terminal block (14). 3. The terminal block (14) as claimed in claim 1, wherein each terminal connection comprising a terminal connection screw (22) which attaches a contact (20) to the terminal block (14) at the first end of its associated tier (14a, b, c). 4. The terminal block (14) as claimed in claim 1, wherein each contact (20) extends beyond the second end of its associated tier (14a, b, c) 5. The terminal block (14) as claimed in claim 1, wherein there are a variable number of tiers (14a, b, c). 6. The terminal block (14) as claimed in claim 1, wherein there are three tiers (14a, b,c). 7. The terminal block (14) as claimed in claim 1, wherein the terminal block (14) is mountable on the protective relay in multiple orientations. 8. The terminal block (14) as claimed in claim 1, wherein the connection terminals (22) and contacts (20) can withstand a current of approximately 500 amps for approximately 1 second. 9. The terminal block (14) as claimed in claim 1, wherein shorting can be provided between any two adjacent terminal connections (22). 10. The terminal block (14) as claimed in claim 1, wherein each tier (14a, b, c) is provided with at least one dovetailed alignment element (58) which allows the tier (14a, b, c) to be slidably engaged with a dovetailed alignment element (56) of an adjacent tier (14a, b, c) to engage adjacent tiers (14a, b, c). 11. A method for assembling a terminal block (14) for a protective relay, comprising the steps of molding a plurality of tier elements (14a, b, c)each having different lengths from the other tier elements (14a, b, c), each tier element (14a, b, c) including a plurality of seat portions (50) each having a first aperture for receiving a terminal connection screw (22). inserting a plurality of electrically conductive contacts (20) of different lengths into tier elements (14a, b, c) having different lengths, each contact (20) including a corresponding seat portion (30) at one end and a relay contact portion at another end, the corresponding seat portion (30) having a second aperture (32) for receiving a terminal connection screw (22); press fitting the contacts (20) into the tier elements (14a, b, c); inserting a plurality of terminal connection screws (22) through the first and second apertures to form a terminal block tier (14a, b, c) having a tier length; assembling two or more terminal block tiers (14a, b, c), each of different tier lengths from the other tiers (14a, b, c), together to form a terminal block (14) to be connected to an electrical distribution system via the terminal connection screws (22), and to be connected to relay processing circuitry (26) via the relay contact portions. 12. The method as claimed in claim 11, comprising the step of attaching a shorting finger (24) to a plurality of contacts (20), each shorting finger (24) being configured so as to be in electrical contact with a shorting finger (24) of an adjacent contact (20) when no relay processing circuitry (26) is connected to the relay contact portions. 13. The method as claimed in claim 11, comprising the step of mounting the terminal block (14) in a protective relay in any one of a plurality of orientations. 14. The method as claimed in claim 11, wherein the step of assembling is performed by slidably engaging a dovetailed alignment element (56) on a first tier (14a, b, c) with corresponding dovetailed alignment element (58) on a second tier (14a, b, c). 15. The method as claimed in claim 11, wherein there are a variable number of tier elements (14a, b, c) in the terminal block (14)

Documents:

in-pct-2000-12-del-assignments.pdf

in-pct-2000-12-del-claims.pdf

in-pct-2000-12-del-complete specification (granted).pdf

in-pct-2000-12-del-correspondence-others.pdf

in-pct-2000-12-del-correspondence-po.pdf

in-pct-2000-12-del-description (complete).pdf

in-pct-2000-12-del-drawings.pdf

in-pct-2000-12-del-form-1.pdf

in-pct-2000-12-del-form-19.pdf

in-pct-2000-12-del-form-2.pdf

in-pct-2000-12-del-form-3.pdf

in-pct-2000-12-del-form-5.pdf

in-pct-2000-12-del-gpa.pdf

in-pct-2000-12-del-pa.pdf

in-pct-2000-12-del-pct-101.pdf

in-pct-2000-12-del-pct-210.pdf