Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R4/00—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation
  • H01R4/24—Connections using contact members penetrating or cutting insulation or cable strands
  • H01R4/2416—Connections using contact members penetrating or cutting insulation or cable strands the contact members having insulation-cutting edges, e.g. of tuning fork type
  • H01R4/242—Connections using contact members penetrating or cutting insulation or cable strands the contact members having insulation-cutting edges, e.g. of tuning fork type the contact members being plates having a single slot
  • H01R4/2425—Flat plates, e.g. multi-layered flat plates
  • H01R4/2429—Flat plates, e.g. multi-layered flat plates mounted in an insulating base
  • H01R4/2433—Flat plates, e.g. multi-layered flat plates mounted in an insulating base one part of the base being movable to push the cable into the slot

Definitions

• This invention relates to electrical connectors for electrical leads, particularly to electrical plugs which are useful for making an electrical connection between an electrical lead and an electrical power outlet.
• an electrical connection e.g. to splice two leads together or to attach an electrical plug to a lead in order to apply power. It is also known to insert a light, or other signal, into an electrical circuit so that it is easy to determine whether current is flowing through a heater or other operational electrical device which forms part of the circuit.
• the light can, for example, be placed in a plug through which the device is connected to a wall outlet in a building or to another power source.
• GFCI ground fault circuit interrupter
• the protection device can, for example, be placed in a plug through which a heater or other operational device is connected to a wall outlet in a building or to another power source.
• absence of the signal light may signify failure of the operational device itself, or failure of the electrical connections to the operational device, or conversion of the protective device into its abnormal state, e.g. failure ("blowing") of the fuse.
• Self-regulating strip heaters which comprise elongate electrodes connected by a conductive polymer resistive element are well-known. In operation, the thermal output of these strip heaters varies in response to changes in the thermal environment and thus serves to limit the maximum temperature which the heater achieves . Such heaters are often used to provide freeze protection of pipes, such as domestic or commercial water lines, or to maintain a constant temperature for pipes in process industries. A number of measures have been proposed for assisting the safe operation of such heaters. Reference may be made, for example, to U.S. Patent No. 4,436,986 (Carlson) and U.S. Patent No. 4,822,983 (Bremner et al) .
• a conductive polymer strip heater when connected to a power supply through an electrical plug which is inserted into a conventional wall outlet and which contains a fuse or other protective device, it is very useful to include, as a part of the plug, a signal device, e.g. a light- emitting diode, which is connected between the two legs of the heater circuit so that it will provide a signal (e.g. will be lit up) only when the power is on and the protective device is in its normal state.
• a signal device e.g. a light- emitting diode
• this invention provides an electrical connector for connecting an electrical lead comprising a first conductor and a second conductor, which connector comprises
• a conductor-receiving member which comprises (a) a first channel in which the first conductor can be placed, and
• closure means for maintaining the conductor-receiving member and the conductor-connecting member in the mated configuration.
• this invention provides an electrical connector which is in the form of an electrical plug for connecting an electrical lead comprising a first conductor and a second conductor to an electrical power outlet.
• this invention provides an electrical assemblywhich comprises a plug according to the second aspect and an electrical fuse which is positioned between the first and second contact sections.
• Figure 1 is a schematic circuit diagram of an electrical connector of the invention which is in the form of an electrical plug
• Figure 2 shows an exploded view of a plug of the invention
• Figure 3 shows a top view of another connector of the invention.
• the connector of the invention is useful for connecting- any- type of electrical lead which comprises a first conductor and a second conductor. It is particularly useful when it is in the form of an electrical plug which is used to connect -an electrical lead to an electrical power outlet.
• the power outlet may be a wall outlet either inside or outside of a bulging, or a * it may be part of a power supply or other suitable souf?ee of -*t power.
• the outlet may be two-hole for connection to a phase and a neutral wire, or three-hole for connection to a phase, a neutral, and a ground (earth) wire.
• the electrical lead may ' any electrical component with a first conductor an ⁇ i. a second conductor, e.g. an electrical power cord.
• the plug is particularly useful in making an electrical connection to a strip heater, i.e. an elongate heating element which comprises at least two electrodes.
• a strip heater i.e. an elongate heating element which comprises at least two electrodes.
• the first conductor is one electrode of the heater and the second conductor is the other electrode of the heater.
• the strip heater may comprise a conductive polymer, i.e. a composition in which a particulate conductive filler is dispersed or otherwise distributed in a polymeric component.
• the electrodes of a self-regulating heater are generally elongate metal wires or braid which are parallel and spaced apart. They are attached to or embedded in a resistive element which comprises the conductive polymer and is often in the form of a continuous strip. In order to p ovide environmental protection and electrical insulation, it is common for the resistive element and the electrodes to be covered by a dielectric layer, e.g. a polymeric jacket. A metallic grounding braid is c '.en present over the dielectric layer in order to provide ph y sical reinforcement and a means of electrically grounding the strip heater.
• PTC behavior is used in this specification to denote a composition or an electrical device which has an R 14 value of at least 2.5 or an R 100 value of at least 10, and preferably both, and particularly one which has an R 30 value of at least 6, where R 14 is the ratio of the resistivities at the end and the beginning of a 14°C range, R 100 is the ratio of the resistivities at the end and the beginning of a 100°C range, and R 30 is the ratio of the resistivities at the end and the beginning of a 30°C range.
• Self-regulating conductive polymer heaters which exhibit PTC behavior, and appropriate conductive polymer compositions, are disclosed in U.S. Patents Nos.
• Figure 1 shows a schematic circuit diagram for an electrical connector in the form of a plug which is designed for insertion into an electrical power outlet.
• a first contact member 2 comprises a first prong 4 which can be inserted into one socket of the outlet and a first fuse-contact section 6.
• a second contact member 8 comprises a second fuse-contact section 10 and a first conductor-contact section 12 to which a first conductor of an electrical lead can be physically and electrically connected.
• a third contact member 14 comprises a second conductor-contact section 16 to which the second conductor of an electrical lead can be physically and electrically connected and a second prong 18 which can be inserted into the other socket of the outlet.
• a signal member 20 is electrically connected between the second and third contact members.
• the signal member 20 is electrically in series with a first resistor 22 and a second resistor 24.
• the signal member 20 provides a signal if a fuse 26 connects the first and second fuse-contact sections 6,10. No signal is provided if there is no electrical connection between the first and second fuse-contact sections 6,10.
• the signal member 20 may be a light, e.g. a light emitting diode (LED) which provides a visual signal, a bell or other apparatus which provides an audio signal, or an electrical switch which can generate an alarm signal. Other types of signal members may be appropriate in different circumstances.
• LED light emitting diode
• the first and second fuse-contact sections 6,10 are positioned to receive a fuse 26.
• the selection of a specific fuse is dependent on the normal operating conditions and the anticipated fault conditions. Particularly preferred when the connection is to be made to a strip heater is a very fast acting fuse, i.e. a fuse which has little, if any intentional delay in the overload region and which "trips" (opens) very-rapidly when the current in the circuit comprising the fuse exceeds the rated value of the fuse.
• Appropriate fuses are very fast-acting ceramic ferrule fuses with a current rating of 10 amperes and a voltage rating of 125/250 volts. Such fuses are available, for example, from the Bussman Division of Cooper Industries under the name Buss GBBTM-10.
• Figure 2 shows an exploded view of one specific embodiment of a connector in the form of a plug which is designed to connect the conductors of a first electrical lead 28 to an - electrical power outlet.
• the electrical lead 28 is a strip heater which comprises a resistive element 30, and embedded therein, a first conductor 32 and a second conductor 34.
• the heater is surrounded by a metallic grounding braid 36.
• Both the first conductor 32 and the second conductor 34 have been stripped of the conductive polymer which comprises the resistive element 30 to allow easy insertion into the conductor- receiving member 38.
• leads e.g. insulated wires, it may not be desirable to remove the polymeric insulation or jacketing material.
• the conductor-receiving member 38 comprises a first channel 40, a second channel 42, and a third channel 44, designed for insertion of the first conductor 32, the second conductor 34, and the grounding lead 36, respectively.
• Each channel is a tunnel which has a frusto- conical opening, both features sized so that the conductors inserted in them can be held by frictional forces.
• the walls of the channels serve to prevent contact between the conductors .
• a radial opening 46,48,50 is cut through each tunnel to allow electrical connection of the inserted conductor to the conductor-contact sections.
• the conductor-receiving member which may include positioning pins or other design elements which are not shown, there is a unique mated configuration.
• the first conductor 32 is in physical and electrical contact with the first conductor-contact section 12
• the second conductor 34 is in physical and electrical contact with the second conductor- contact section 16
• the grounding lead 36 is in physical and electrical contact with the grounding contact section 54.
• the first and second conductor-contact sections 12, 16 and the grounding contact section 54 may comprise insulation-piercing means for use when the conductors are insulated with a polymeric jacket.
• the conductor-connecting member further comprises first and second fuse-contact sections 6, 10 designed to receive a fuse.
• the first connection-making section 4 corresponds to the first prong of Figure 1 and the second connection-making section 18 corresponds to the second prong.
• a ground-connection-making section 56 is also present to connect to the ground in the outlet.
• the embodiment shown also comprises a base 58 for the conductor-connecting member 52 which can be welded, glued, or snapped into place.
• a signal port 60 is positioned so that the signal member 20 will be visible.
• Figure 2B shows the bottom of the conductor-connecting member 52 with the base 58 removed.
• the signal member 20, an LED, and first and second resistors 22,24 are visible.
• the first fuse-contact section 6 and the first connection-making section 4 are made from a single piece of metal, e.g. brass.
• the second conductor-contact section 16 and the second connection-making section 18 are also made from a single piece of metal, as are the second fuse-contact section 10 and the fuse conductor-contact section 12.
• the conductor-receiving member 38 is preferably made from an insulating material, e.g. a polymer. It is particularly- preferred that it be made from a transparent polymer, e.g. polycarbonate, so that there is a visual indication that the conductors are properly positioned.
• the conductor-receiving member 38 and the conductor-connecting member 52 are maintained in position by a closure means 62, e.g. a screw or a clamp. When mated properly, the plug provides adequate strain relief to the electrical lead. A minimum pull force of 20 pounds on the electrical lead is achieved. (The "pull force” or “pullout force” measures the amount of force required to pull the electrical lead 0.125 inch (0.318 cm) out of the plug.
• Figure 3 illustrates a connector 64 which is designed to connect a first electrical lead 28 comprising first and second conductors 32,34 and a second electrical lead 66 comprising third and fourth conductors 68,70.
• this connector 64 there are two conductor-receiving members 38,72.
• the second conductor-receiving member 72 comprises two channels 74,76 for insertion of the third and fourth conductors 66,68.
• a second closure means 78 maintains the second conductor-receiving member 72 in the mated configuration.
• the third conductor 68 makes physical and electrical contact with the first connection-making section 4
• the fourth conductor 70 makes physical and electrical contact with the second connection-making section 18.

Landscapes

• Details Of Connecting Devices For Male And Female Coupling (AREA)
• Resistance Heating (AREA)
• Connector Housings Or Holding Contact Members (AREA)

Applications Claiming Priority (5)

Publications (2)

Family

ID=27023091

Family Applications (1)

Country Status (5)

Families Citing this family (5)

Family Cites Families (5)

• 1990
  • 1990-10-02 EP EP90915605A patent/EP0494963B1/de not_active Expired - Lifetime
  • 1990-10-02 CA CA002066272A patent/CA2066272A1/en not_active Abandoned
  • 1990-10-02 DE DE69026102T patent/DE69026102T2/de not_active Expired - Fee Related
  • 1990-10-02 AT AT90915605T patent/ATE135851T1/de not_active IP Right Cessation
  • 1990-10-02 WO PCT/US1990/005613 patent/WO1991005377A1/en active IP Right Grant

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events