Not applicable
The present disclosure relates to safety equipment for men working on electrical power distribution equipment such as terminal blocks in a substation or the like and more particularly to a device for identifying and covering terminal connections in a terminal block to prevent inadvertent disconnection of electrical connections and subsequent power failures.
Terminal blocks (also called terminal strips, connection terminals or screw terminals) are known to the art and provide a convenient means of connecting individual electrical wires without a splice or physically joining the ends. They are usually used to connect wiring among various items of equipment within an enclosure or to make connections among individually enclosed items. Terminal blocks are readily available for a wide range of wire sizes and terminal quantity. They are widely used in electric substations to connect wires from various sources including safety and monitoring equipment.
Terminal Blocks generally are modular, insulated sections that fasten two or more wires together allow wiring to be centralized and make it easier to manage complicated control circuits. When modifications in the circuit must be carried out, terminal blocks can be easily added or removed from a rail without interfering with other wire terminations. In addition to minimizing complexity of control wiring, the plastic frames of terminal blocks also protect against shorts and subsequently provide increased safety to installers and service crews.
One disadvantage is that a substation, for example, can house thousands of connecting wires. The connecting wires are not well marked. Furthermore, the terminals are generally not very well protected from contact with persons or foreign conducting materials. In any event, if a technician erroneously disconnects the wrong wires from a terminal block, it can cause power failure, sometimes a catastrophic cascade of power failure in an interconnected power grid.
It would be advantageous, therefore, to have an apparatus for connecting to a terminal block that both covers those wire connections to prevent inadvertent disconnection of wires and resultant power failure, and indicates which connections should be avoided or worked on.
A safety cover and identifier is disclosed to cover wire terminals and wire connections in an electric terminal block to prevent inadvertent disconnection of wires and indicate which connections should be avoided or worked on. The cover/identifier comprises a body having a first substantially flat leg and an opposed, spaced apart mirror image second leg The two legs are joined adjacent their midpoints by an integral, resilient spring element. The opposed proximal ends of the legs each define serrated jaws. The jaws are opened by compression of the distal ends of the legs. The jaws are attached to the electrical terminal block to cover wire connections and each of the proximal ends covers one of a functional pair of wire connectors. The resilient spring element biases the jaws toward each other to secure the cover in place. The cover/identifier includes indicia to identify aspects of the wires attached to the cover wire connectors.
In another aspect, the proximal ends of each leg define an opening for a connector to connect two or more cover and identifiers together side-by-side.
In another aspect, the distal ends of each leg each define an opening for the attachment of a connector or an identifier.
In another aspect the safety cover and identifier is molded from a dielectric material.
In another aspect the safety cover and identifier is provided in predetermined color indicia.
The safety cover/identifier disclosed herein is designed to be use with a conventional terminal block. By way of example, it is designed to be used with terminal blocks employed in the high voltage electric distribution industry. One example is electric terminal blocks employed in electric substations and the like. However, it can be used in any environment and is not limited to the high voltage electric distribution industry.
Representative examples of terminal blocks are shown in
The current carrying parts consist of wire terminals 14, including a clamping device 15. As shown, the terminal block includes two banks of opposed wire terminals. Each pair of opposed wire terminals is electrically connected by a current bar (not seen). The current bar, at the core of the insulating body 12, is constructed from copper or brass. The clamping device 15 fastens a wire to a wire terminal 14 in the terminal block, for example with screw 16, and creates a dependable electric connection between the wire and the current carrying bar. The dimensions of the current carrying parts vary in regard to the amperage/wire size and the construction of the block itself. Depending upon terminal block layout, wires can be clamped in position using screws 16 a combination of screws and pressure plates or other appropriate elements.
It will be noted that the terminal block includes a plurality of pairs of wire terminals 14. In the embodiment shown, one wire terminal 14 accommodates a wire, e.g. W1 carrying electric current toward the block and one terminal accommodates a wire carrying electric current away from the block. For purposes of description such a pair of wire terminals may be referred to as a functional pair of wire terminals. Hence, the terminal block serves to connect two sections of a single functional wire though a functional pair of wire terminals joined by a current bar. It will be appreciated that if one of the wires is disconnected from a wire terminal, current flow through the block will stop, with concomitant consequences.
As mentioned above, terminal block 10A or 10B serves to connect two sections of a plurality of pairs of wires W1, W2; W3, W4 and so forth. In the illustrated embodiments of the terminal blocks, the ends of the wires terminate in a metal connector 18 such as a wire clip or metal loops which is attached to the wire terminal 14 by screws 16 so as to be in electrical contact. The number of pairs of wires can vary according to the size of the terminal block, the number of pairs of wire terminals, and the environment and application of use for the terminal block. Suffice to say, that a terminal block or series of terminal blocks in any given environment can connect hundreds or even thousands of pairs of wires.
Each wire terminal 14 is separated laterally from the adjacent wire terminal by a divider or wall 20A in block B1 and wall 20B in block B2. These dividers are constructed from a dielectric material and isolate adjacent wire terminals from each other. As shown, walls 20A in block 10A are substantially flat. On the other hand, walls 20B in block 10B have a substantially T-shaped cross-section defined by shoulders 22 and 24.
There is a center, transverse divider 26 extending the middle length of the block separating the opposed banks of wire terminals. Divider 26 can be integral or can be a flat plate fastened to the block by a screw 28 or other means. Divider 26 delineates one side of the terminal block, with its array of wire terminals, from the other side of the terminal block and its complementary array or wire terminals.
Each representative terminal block includes some means for mounting the terminal block in its useful environment. For example holes 29 in the corners of body 12 can accept screws or nut and bolt combinations or other fasteners to secure the terminal block to a terminal block channel or directly to a structure, or the like. The mounting means is incidental to the disclosure.
As can be seen in
One aspect of the cover/identifier, referred to by reference number 32, is shown in greater detail in
Device 32, as shown, includes a unitary body 33 comprising a first leg 34 and a second opposed leg 36. The respective legs, as shown, are mirror images joined at their approximate midpoints by a resilient spring structure 38. In the illustrated device, spring structure 38 is generally C-shaped, however, any configuration that functions as intended is included within the scope of the disclosure. By way of example only, resilient spring structure 38 could be V-shaped. X-shaped, circular or any other useful configuration.
Device 32 is comprised of a dielectric material, such as a molded plastic material. For example polypropylene or urethane or other plastic materials work well. In a preferred aspect, device 32 is molded as one piece in a cavity mold. However, any method of making the device is acceptable. Moreover, the various elements of device 32 may be constructed separately and assembled.
It will be noted that leg 34 and leg 36 are mirror images of each other, although they would not have to be. As best seen in
In any event, in the illustrated aspect the material thickness of the spring structure itself is thinner than the thickness of the legs, such that it is compressible and resilient. The distal ends of the legs can be compressed toward each other but are urged to return toward their original orientation after compressive force is removed by the resilient biasing function of spring structure 38. As seen in
Each proximal end 40 has a bottom margin 48 with a lateral width approximately the same as the width of spring structure 38. Each bottom margin 48 is contiguous with the spring structure and includes forward serrated surface 50. As shown, the spring structure 38, bottom margins 48, forward serrated surfaces 50 of the two legs cooperate to form a pair of opposed jaws. A user can apply minimal compressive force to the distal ends of the legs to overcome the biased torsional force of spring structure 38 to open the jaws and upon release, the spring structure biases the jaws toward each other so as to apply clamping force on the jaws.
As seen in
As seen in
The indicator aspect of device 32 is two-fold and will now be discussed in greater detail. It will be noted that device 32 can be molded in any desired color. Consequently, the color of each device can function as identifying indicia. The devices can be provided in a plurality of identifying colors. By way of example only, device 32 in red could serve as a warning indicator that the wires or wire connections covered by a red device 32 should not be disconnected under any circumstances. Conversely, wires and wire connections requiring service could be covered with green devices. Red and green are mentioned for purposes of illustration only. The devices could be color coded to indicate the electric equipment energized by any given set of wires connected through a terminal block. Suffice to say, color coding of devices 32 could perform myriad identification functions. Hence, the device can be constructed in a predetermined color that correspondence to predetermined indicia that is readily identifiable by a technician or other individual.
Furthermore, as seen in
It will be appreciated that various changes and modifications may be made in device 32 without departing from the scope of the appended claims. Therefore, the detailed disclosure and accompanying drawings should be considered illustrative of broader aspects of the device and should not be viewed as limiting in any sense
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