Patent Application
20190140405
Industrial environments (e.g., mining, paint and coatings, oil and gas, robotic manufacturing lines, high dust industrial environments, etc.) are governed by strict safety standards, such as 29 CFR 1910 and 29 CFR 1926 (April 2017), with equipment regulated by safety standards, such as UL 1203 and UL 844, to prevent explosions due to sparks or arcing originating from electrical wires and connectors. For example, when power is left on during the uncoupling of a connector, arcing can occur between the electrical connectors as they disengage. If combustible conditions are present (e.g. dust, vapors, gases, etc), as is often the case in industrial environments, this arcing can lead to an explosion. Safety standards typically specify permissible electrical wires and connectors including materials, flame paths (e.g., spark production), conductor separation distances, maximum gap distances, etc. A variety of connectors have been designed that meet the applicable safety standards. Despite compliance with such safety standards, however, there is room for improvement in connector designs to make connectors that are robust (e.g., fool-proof), reduced risk, and user friendly.
A safety electrical power connector is disclosed herein that can meet safety standards by mechanical and physical isolation of connector contacts from surrounding environment as those contacts come into close proximity. In one aspect, the safety electrical power connector can facilitate safe connect/disconnect while power is on by mechanically severing power within the connector upon disconnect and therefore no need for an operator to turn power off or de-energize the lines when connecting/disconnecting. The safety electrical power connector can include a first connector body having a first electrical contact and an outer surface, and a second connector body that engages the first connector body in an axial direction. The second connector body can have a second electrical contact and an inner surface configured to slide relative to the outer surface of the first connector body in the axial direction during engagement of the first and second connector bodies. The outer surface and the inner surface can define a gap therebetween sufficient to establish an isolation enclosure that isolates a volume containing the first and second electrical contacts therein. The gap can be formed prior to electrical communication of the first and second electrical contacts thereby preventing an explosion due to arcing between the first and second electrical contacts.
There has thus been outlined, rather broadly, the more important features of the invention so that the detailed description thereof that follows may be better understood, and so that the present contribution to the art may be better appreciated. Other features of the present invention will become clearer from the following detailed description of the invention, taken with the accompanying drawings and claims, or may be learned by the practice of the invention.
These drawings are provided to illustrate various aspects of the invention and are not intended to be limiting of the scope in terms of dimensions, materials, configurations, arrangements or proportions unless otherwise limited by the claims.
While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be realized and that various changes to the invention may be made without departing from the spirit and scope of the present invention. Thus, the following more detailed description of the embodiments of the present invention is not intended to limit the scope of the invention, as claimed, but is presented for purposes of illustration only and not limitation to describe the features and characteristics of the present invention, to set forth the best mode of operation of the invention, and to sufficiently enable one skilled in the art to practice the invention. Accordingly, the scope of the present invention is to be defined solely by the appended claims.
In describing and claiming the present invention, the following terminology will be used.
The singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “an electrical contact” includes reference to one or more of such features and reference to “engaging” refers to one or more of such steps.
As used herein with respect to an identified property or circumstance, “substantially” refers to a degree of deviation that is sufficiently small so as to not measurably detract from the identified property or circumstance. The exact degree of deviation allowable may in some cases depend on the specific context.
As used herein, the term “about” is used to provide flexibility and imprecision associated with a given term, metric or value. The degree of flexibility for a particular variable can be readily determined by one skilled in the art. However, unless otherwise enunciated, the term “about” generally connotes flexibility of less than 2%, and most often less than 1%, and in some cases less than 0.01%.
As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary.
As used herein, the term “at least one of” is intended to be synonymous with “one or more of” For example, “at least one of A, B and C” explicitly includes only A, only B, only C, or combinations of each.
Numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a numerical range of about 1 to about 4.5 should be interpreted to include not only the explicitly recited limits of 1 to about 4.5, but also to include individual numerals such as 2, 3, 4, and sub-ranges such as 1 to 3, 2 to 4, etc. The same principle applies to ranges reciting only one numerical value, such as “less than about 4.5,” which should be interpreted to include all of the above-recited values and ranges. Further, such an interpretation should apply regardless of the breadth of the range or the characteristic being described.
Any steps recited in any method or process claims may be executed in any order and are not limited to the order presented in the claims. Means-plus-function or step-plus-function limitations will only be employed where for a specific claim limitation all of the following conditions are present in that limitation: a) “means for” or “step for” is expressly recited; and b) a corresponding function is expressly recited. The structure, material or acts that support the means-plus function are expressly recited in the description herein. Accordingly, the scope of the invention should be determined solely by the appended claims and their legal equivalents, rather than by the descriptions and examples given herein.
Safety Electrical Power Connector
With reference to
In one aspect, the connector body 101 can be configured as a plug and the connector body 102 can be configured as a socket that receives the plug. For example, the connector body 101 can have an outer surface 111, and the connector body 102 can have a complimentary inner surface 121 configured to slide relative to the outer surface 111 of the connector body 101 in the axial direction 103 during engagement of the connector bodies 101, 102. In one embodiment, the outer and complimentary inner surfaces 111, 121 can be cylindrical, although it should be recognized that these surfaces can have any suitable shape or configuration. Generally the outer an inner complimentary surfaces can have a constant complimentary cross-section over the engagement portion. Non-limiting examples of suitable surface shapes can include cylindrical, square, rectangular, elliptical, triangular, hexagonal, pentagonal, and the like, including such shapes having rounded vertices or corners.
The connector 100 can also include a securing member 130 associated with the connector body 101 or the connector body 102 to secure the connector bodies 101, 102 to one another. In some embodiments, the securing member 130 can comprise a threaded sleeve configured to threadingly engage a threaded surface of the connector body 101 or the connector body 102. In the illustrated embodiment, the securing member 130 is associated with the connector body 101. The securing member 130 can have an inwardly oriented flange 131 configured to bear against an outwardly oriented flange 112 of the connector body 101. A capture member 140 can be coupled to the connector body 101 (e.g., via a threaded interface) to capture the securing member 130 such that the securing member 130 is maintained about the connector body 101, such as when disconnected from the connector body 102. In addition, the securing member 130 can comprise a threaded sleeve having a threaded surface 132 configured to threadingly engage a threaded surface 122 of the connector body 102. As described in more detail below, the threaded surfaces 122, 132 can facilitate coupling and uncoupling of the connector bodies 101, 102 in addition to securing the connector bodies once coupled to one another. During disconnect the securing member 130 can bear against the capture member 140 while unthreading from the connector 102 to facilitate movement of the connector bodies 101, 102 away from one another. The securing member 130 and the capture member 140 can be constructed of any suitable material, such as a metal material (e.g., aluminum, copper, iron, etc. alone or in any combination).
The connector 100 can include a seal 150 configured to interface with the connector bodies 101, 102 to form a seal between the connector bodies 101, 102 when coupled or connected to one another. The seal 150 can form a barrier protecting the electrical connections from environmental conditions. When sealed, the connector 100 can be resistant to water and/or debris. In the illustrated embodiment, the seal 150 is disposed about the connector body 101 proximate the outer surface 111. The seal 150 can be constructed of any suitable material, such as a polymeric material. In some cases, the seal 150 can be a gasket or other continuous ring or loop structures.
The electrical contacts 110a-c, 120a-c can be associated with or coupled to any suitable conductor of an electrical power line (not shown). For example, the corresponding electrical contacts 110b, 120b and the corresponding electrical contacts 110c, 120c can be associated with supply, common, and/or neutral conductors of electrical power lines and can therefore be referred to as supply, common, and/or neutral contacts, as applicable (including variations in loading, signal, etc). In addition, the corresponding electrical contacts can be associated with ground conductors of electrical power lines and can therefore be referred to as ground contacts. In general, the electrical contacts 110a-c, 120a-c can be designed for bulk power coupling. As a general guideline, bulk power couplings can include high capacity couplings to building main power lines, high capacity modular generators used to power work environments with demanding loads, electrical systems with multiple drop points of power hook-up, and the like. Further, high power lines may utilize single contact coupling connectors; although, the system as a whole, would not be energized until proper contacts are confirmed, and the feedback sensor loop is properly established.
Regardless, the contact materials, e.g. copper, aluminum, brass, and diameters should meet minimum NEC wire diameter based upon current flow through the powered system. For example, a 30 A capacity system, requires 10 AWG copper wire, which measures 0.5261 mm2, with a diameter of 2.588 mm. Thus, the contact for best performance, would meet these same dimensional criteria. Although three corresponding electrical contacts (i.e., pairs) are shown in the illustrated embodiment, it should be recognized that a safety electrical power connector in accordance with the present disclosure can include any suitable number of electrical contacts as desired to adequately couple the number and type of conductors in a given electrical power line.
The connector bodies 101, 102 can be constructed of any suitable material. In some embodiments, one or both of the connector bodies 101, 102 can be constructed of a metal material (e.g., aluminum, copper, iron, nickel, etc. alone or in any combination). In such cases, the electrical contacts 110a-c, 120a-c can be separated from the metal material by electrically insulative liners or sleeves. In one embodiment, the electrical contacts 110b, 110c, 120b, 120c can be supply, common, and/or neutral contacts and can therefore be separated from metal material of the connector bodies 101, 102 by electrically insulative liners 113b, 113c, 123b, 123c disposed about the respective electrical contacts. The electrical contacts 110a, 120a can be ground contacts and can therefore be in contact with the metal material of the connector bodies 101, 102. The electrically insulative liners 113b, 113c, 123b, 123c can be constructed of any suitable material, such as a dielectric material (e.g., a suitable polymer). The electrical contacts and the electrically insulative liners can be coupled to one another and to the connector bodies 101, 102 in any suitable manner, such as threadedly coupled, adhesively coupled, and/or configured to have an interference fit.
The electrical contacts 110a-c, 120a-c can have any suitable configuration. For example, the 110a-c, 120a-c can include a pin, a pogo pin, a receptacle, a landing, a pad, etc. alone or in any combination. In the illustrated embodiment, the electrical contacts 110a, 110b, 120c can comprise fixed pins and the electrical contacts 110c, 120a, 120b can comprise pogo pins (i.e., spring-loaded pins). The pogo pins can move in the direction 103 parallel to the axis 104 of the connector 100. The pin heads or contact surfaces can have any suitable shape or configuration, such as rounded (e.g., semi-spherical), flat, pointed, etc. In one aspect, fixed or pogo pins can be flush or recessed with respect to facing surfaces 114, 124 of the respective connector bodies 101, 102. For example, the fixed pins 110a, 110b can have flat contact surfaces flush or (slightly) recessed with respect to the facing surface 114. The pogo pin 110c can have a flat contact surface flush or (slightly) recessed with respect to the facing surface 114. In another aspect, fixed or pogo pins can protrude with respect to the facing surfaces 114, 124. For example, the pogo pins 120a, 120b can have contact surfaces that protrude with respect to the facing surface 124. In addition, the fixed pin 120c can have a contact surface that protrudes with respect to the facing surface 124. Protruding pins can have any suitable protrusion length from the facing surfaces 114, 124. For example, the protruding pins 120a-c can protrude from the facing surface 124 by protrusion lengths 125a-c, respectively.
In one aspect, fixed and pogo pins can be configured to facilitate ease of cleaning and avoidance of debris build-up. For example, the flush or recessed pins 110a-c and the facing surface 114 can provide a substantially flat surface that is easily cleaned and does not promote accumulation of debris. In addition, the use of spring-loaded contacts can enable the protruding pins 120a-c to have protrusion lengths 125a-c configured to allow the pins 120a-c to be readily cleaned and avoid trapping or capturing debris. In one embodiment, the protruding pins 120a-c can be configured as stubs with minimal protrusion lengths 125a-c. As a general guideline, protrusion lengths can vary from about 0.5 mm to 5 mm, and most often from 2 mm to 4 mm. The pogo pins 110c, 120a, 120b can provide any suitable range of motion or travel to accommodate a given distance between the facing surfaces 114, 124 and the protrusion lengths 125a-c. The pogo pins 110c, 120a, 120b can therefore provide a reliable electrical contact with the corresponding fixed pins 120c, 110a, 110b when the connector bodies 101, 102 are coupled with one another.
In one aspect, the ground contacts 110a, 120a can be configured to contact one another prior to the other contacts 110b, 120b and 110c, 120c (e.g., supply, common, and/or neutral contacts) contacting one another when the connector bodies 101, 102 are engaged with one another. In addition, the ground contacts 110a, 120a can disconnect from one another after the other contacts 110b, 120b and 110c, 120c disconnect from one another when the connector bodies 101, 102 are disengaged from one another to prevent sparking. For example, the protrusion length 125a of the ground contact 120a can be greater than the protrusion lengths 125b, 125c of the other contacts (e.g. supply, common, and/or neutral contacts), which can enable prior contact and earlier separation of the ground contacts 110a, 120a relative to the other contacts 110b, 120b, and 110c, 120c. Other protrusion lengths can be configured to establish an order of contact and separation of the various contacts. For example, the protrusion length 125b can be greater than the protrusion length 125c such that the contacts 110b, 120b contact one another prior to the contacts 110c, 120c contacting one another, and separate after the contacts 110c, 120c separate from one another.
In some embodiments, the connector 100 can be configured to mechanically sever power when the connector bodies 101, 102 begin to be separated from one another. For example, the contact 110c can be associated with or configured as an interlock mechanism 160 that provides electrical continuity when the connector bodies 101, 102 are fully engaged and severs electrical continuity when the connector bodies 101, 102 become disengaged or begin to be separated from one another. In most cases, the interlock mechanism 160 can sever power with contact 110c until the connector bodies 101, 102 are sufficiently engaged to isolate the contacts as described in more detail herein. In one aspect, the connector body 101 can supply power to the connector body 102 (e.g., the connector body 101 can be coupled to a power source for delivery to a power consuming device coupled to the connector body 102). Thus, severing power in the connector body 101 can sever power in both the connector bodies 101, 102. The interlock mechanism 160 can include interlock contact pins 161, 162 that contact one another when the connector bodies 101, 102 are fully engaged, and separate from one another to sever electrical continuity when the connector bodies 101, 102 become disengaged or begin to be separated from one another. In other words, the interlock contact pins 161, 162 can be normally open or electrically disconnected from one another by a gap 163, thus severing power in the connector body 101 to provide safe handling of the connector bodies 101, 102 when disconnected. The interlock contact 161 can be spring-loaded and biased away from the interlock contact 162. In addition, the interlock contact 162 can be spring-loaded and biased toward the interlock contact 161. Upon contact with the fixed protruding pin 120c due to movement of the connector bodies 101, 102 toward one another, the interlock contact 161 begins to move toward the interlock contact 162. Once contact is made between the interlock contacts 161, 162, there is electrical continuity through the contact 110c. The spring-loaded interlock contact 162 can accommodate additional movement of the interlock contact 161 against the interlock contact 162, such as due to additional movement of the connector bodies 101, 102 toward one another. When the connector bodies 101, 102 move away from one another, movement of the fixed protruding pin 120c away from the connector body 101 allows the biased interlock contact 161 to move away from the interlock contact 162 once the interlock contact 162 has biased against its travel stop. When the interlock contacts 161, 162 separate from one another there is electrical discontinuity in the contact 110c, thus severing power in the connector body 101. Because the connector body 102 is not coupled to a power source and power is severed within the connector body 101, the connector bodies 101, 102 are safe and unable to generate sparks or arcing when disconnected. Thus, the connector 100 can facilitate safe connect/disconnect of the connector bodies 101, 102 while power is “hot” with no need to manually turn power off or de-energize the lines.
In one aspect, the interlock mechanism 160 can be connected to a load control apparatus having an interlock circuit that electrically uncouples an input load terminal to prevent power from reaching an output load terminal, such as the electrical contact 110c via the interlock mechanism 160. As mentioned above, the electrical contacts 110c, 120c can be configured to contact one another after the other contacts have contacted one another and to separate from one another prior to separation of the other contacts. This can ensure that there is never a generated spark at the electrical contacts. In one specific example, the contacts can contact one another upon assembly in the following order: ground, common, other conductors (interlocked or not), positive (with an interlock), and sensor (a low-voltage line connected to an interlock circuit which can optionally include an interlock mechanism). The interlock mechanism 160 can therefore serve as a sensor triggering an auto-relay system (e.g., the interlock circuit) to provide additional safety as well as increase the life of the electrical contacts due to reducing or eliminating surface damage resulting from arcing between the contacts. Alternatively, the sensor line can be an optically conductive path (e.g. non-electrical path) such as an optically conductive pin associated with an optical cable. The interlock mechanism 160 can generally be oriented on the positive conductor. Additional description of a corresponding interlock circuit can be found in copending U.S. Provisional Patent Application No. 62/537,787, filed July 27, which is incorporated herein by reference.
The connector bodies 101, 102 can include alignment surfaces 116, 126, respectively, that engage and mate with one another to facilitate alignment of the corresponding electrical contacts. The alignment surfaces 116, 126 can have any suitable shape or configuration. One example is shown in
The alignment surface 216, an outer surface 211, and the facing surface 214 can form part of a plug or protruding configuration. The alignment surface 226, an inner surface 221, and the facing surface 224 can form part of a receptacle or socket configuration. Thus, electrical contacts 210a, 210b, 210b′, 210c can be exposed at an end of the plug connector body 201, and electrical contacts 220a, 220b, 220b′, 220c can be exposed within the socket connector body 202. In this example, the alignment surfaces 216, 226 each include a semicircular portion and two flat portions. The flat portions establish and maintain a given relationship between the alignment surfaces 216, 226 to properly align the corresponding electrical contacts of the connector bodies 201, 202. Thus, generally the alignment surfaces can have a keyed relationship such that only a single orientation is allowed when the socket connector and plug connector body are engaged. Other keyed shapes can also be used such as, but not limited to, asymmetric shapes, kidney shapes, multiple lobe shapes, regular shapes (e.g. circular, square, rectangular, triangular, hexagonal, etc) having complimentary key notches, and the like. These shapes are based upon a two-dimensional x-y cross-section. However, the alignment surfaces can occur in a z-direction. For example, varying contact heights can facilitate the complimentary keyed relationship for alignment. In another example, a circular design as the primary mating faces can have secondary contacts of varying height to ensure a keyed interface.
In yet another alternative, the keyed interface can be external to the contacts and designed into the outer housing of the connector. In one example, the outer housing could be trapezoidal in shape with clips to retain the coupling once made, e.g. a larger version of panel mount multi-pin D Sub connectors for computers.
Corresponding electrical contacts can be disposed or arranged in any suitable configuration (e.g., pattern) and the alignment surfaces 216, 226 can be configured to align the corresponding electrical contacts with one another. In some embodiments, the outer and inner surfaces 211, 221 can also be configured as alignment surfaces to provide the alignment functions described herein.
With further reference to
With the alignment surfaces 116, 126 properly oriented, the connector bodies 101, 102 can be moved further toward one another. At a certain point, as shown in
With the outer and inner surfaces 111, 121 engaged and isolating the electrical contacts, the connector bodies 101, 102 can safely be moved further toward one another. This movement can be caused by the threaded engagement of the threaded surface 132 of the securing member 130 and the threaded surface 122 of the connector body 102. As shown in
The order of pin contact might be needed to ensure a specific order of operations in equipment energization. For example, multiple systems powered off a single multiconductor coupling can require that a first system A is energized immediately prior to System B, immediately prior to System C, etc. In another example, the order of operations is triggering a sequence of illumination or an alarm sequence, etc. By changing the coupling system, the time interval between pin contacts can be varied, as well. In the illustrated example, a threaded collar controls a separate time interval for contacts to connect. More threads per inch increases this time interval. Multiple collar engagements can further change the coupling time interval based on specific applications.
In some embodiments, the corresponding electrical contacts 110c, 120c can be configured to contact one another last after contact of all other electrical contacts when coupling the connector bodies 101, 102, as shown in
The connector bodies 101, 102 can be further moved toward one another to compress the seal 150 between the connector bodies 101, 102, as shown in
The above-described process for connecting the connector bodies 101, 102 is generally reversed when disconnecting the connector bodies, which disconnects the various electrical connections formed during connection of the connector bodies. Thus, as the connector bodies 101, 102 begin to separate from one another, the interlock contacts 161, 162 of the interlock mechanism 160 can also separate from one another creating an electrical discontinuity in an energized line and thereby prevent sparks from occurring regardless of any space between contacts. In addition, all electrical contacts are separated from one another while the inner and outer surfaces 111, 121 are still engaged with one another, with ground contacts being the final contacts to separate to avoid sparks or arcing. The electrical contacts are therefore isolated from the exterior environment of the connector 100 until well after the corresponding contacts have separated from one another with no flame or spark path existing to the exterior of the connector that could potentially ignite flammable material (e.g., gases). These features allow the connector bodies to be safely separated from one another in a hazardous area (e.g., an industrial environment) without the need for a user to actively switch off power to the connector 100. In addition, because the interlock mechanism 160 mechanically severs power in the connector body 101 that supplies power to the connector body 102, the connector bodies are both safe after they have been separated from one another.
The foregoing detailed description describes the invention with reference to specific exemplary embodiments. However, it will be appreciated that various modifications and changes can be made without departing from the scope of the present invention as set forth in the appended claims. The detailed description and accompanying drawings are to be regarded as merely illustrative, rather than as restrictive, and all such modifications or changes, if any, are intended to fall within the scope of the present invention as described and set forth herein.
This application claims priority to U.S. Provisional Application No. 62/534,517, filed Jul. 19, 2017 which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62534517 | Jul 2017 | US |
