Patent Description:
Vehicles, such as aircraft, commonly include fire and overheat detection systems for monitoring spaces within the vehicle for fire and/or overheating. Fire and overheating detection systems generally include thermal detectors and/or other types of sensor elements to provide an indication of elevated temperature and/or of fire events. The thermal detectors and/or sensor elements are typically supported within (or within view) to the space monitored for fire and/or overheating, generally using a mounting structure. <CIT> is concerned with a mounting bracket assembly for an electrical cable. The mounting bracket of US'<NUM> can be secured to a jet engine of an aircraft. The electrical cable can then be connected to a fire detector.

In the case of gas turbine engines, mounting systems typically space the thermal detectors and/or sensor elements away from the engine structure. This allows the thermal detector and/or sensor element to monitors temperature between the engine and the nacelle, avoids the need to directly contact hot surfaces of the engine, and allows the mounting system to dampen vibration communicated to the thermal detector or sensor element from the engine. In some engines the temperature between the engine and the nacelle can rise to above those at which polymeric materials and polytetrafluoroethylene (PTFE) materials change, e.g., becoming brittle or melting, limiting the ability of the mounting system to dampen vibration communicated to the thermal detector and/or sensor element.

According to a first aspect of the invention there is provided an aircraft fire and overheat detection system according to claim <NUM>.

In embodiments the aircraft fire and overheat detection system may include that the protective sleeve is made from at least one of polyolefin, fluoropolymer, polyvinyl chloride (PVC), polychloroprene (neoprene), and silicone elastomer.

In addition to one or more of the features described above, or as an alternative, further embodiments of the aircraft fire and overheat detection systems may include an adhesive sealant applied to a surface of the interior bore.

In addition to one or more of the features described above, or as an alternative, further embodiments of the aircraft fire and overheat detection systems may include that the adhesive sealant is applied at least to the first wire portion.

In addition to one or more of the features described above, or as an alternative, further embodiments of the aircraft fire and overheat detection systems may include that the adhesive sealant is applied at least to the second wire portion.

In addition to one or more of the features described above, or as an alternative, further embodiments of the aircraft fire and overheat detection systems may include that the adhesive sealant is at least one of hot-melt, silicone, elastomer, and epoxy.

In addition to one or more of the features described above, or as an alternative, further embodiments of the aircraft fire and overheat detection systems may include that the third diameter is less than an external diameter of the connection cable.

In addition to one or more of the features described above, or as an alternative, further embodiments of the aircraft fire and overheat detection systems may include that the second diameter is substantially equal to an external diameter of the connection cable.

In addition to one or more of the features described above, or as an alternative, further embodiments of the aircraft fire and overheat detection systems may include that the protective sleeve comprises a first transition portion defining a tapering diameter between the lug portion and the first wire portion.

In addition to one or more of the features described above, or as an alternative, further embodiments of the aircraft fire and overheat detection systems may include that the protective sleeve comprises a second transition portion defining a tapering diameter between the first wire portion and the second wire portion.

According to a second aspect of the invention there is provided an aircraft according to claim <NUM>.

In embodiments the aircraft may include that the fire protected space is located within a portion of an engine of the aircraft.

In addition to one or more of the features described above, or as an alternative, further embodiments of the aircraft may include that the protective sleeve is made from at least one of polyolefin, fluoropolymer, polyvinyl chloride (PVC), polychloroprene (neoprene), and silicone elastomer.

In addition to one or more of the features described above, or as an alternative, further embodiments of the aircraft may include an adhesive sealant applied to a surface of the interior bore.

In addition to one or more of the features described above, or as an alternative, further embodiments of the aircraft may include that the third diameter is less than an external diameter of the connection cable.

In addition to one or more of the features described above, or as an alternative, further embodiments of the aircraft may include that the second diameter is substantially equal to an external diameter of the connection cable.

In addition to one or more of the features described above, or as an alternative, further embodiments of the aircraft may include that the protective sleeve comprises a first transition portion defining a tapering diameter between the lug portion and the first wire portion and a second transition portion defining a tapering diameter between the first wire portion and the second wire portion.

The foregoing features and elements may be executed or utilized in various combinations without exclusivity, unless expressly indicated otherwise.

Reference will now be made to the drawings. For purposes of explanation and illustration, and not limitation, <FIG> illustrates a partial view of an example embodiment of a gas turbine engine <NUM> that incorporates a fire and overheat detection system <NUM> that may incorporate embodiments of the present disclosure is shown. It will be appreciated that other embodiments of fire and overheat detection systems in accordance with the present disclosure, or aspects thereof, may be implemented without departing from the scope of the present disclosure. The systems described herein can be used for providing improved sensing of sensor elements in fire and overheat detection systems in gas turbines, such as in aircraft.

Referring to <FIG>, a gas turbine engine <NUM> is shown. The gas turbine engine <NUM> includes a compressor <NUM>, a combustor <NUM>, and a turbine <NUM>. The gas turbine engine <NUM> also includes a case <NUM>, a nacelle <NUM>, and the fire and overheat detection system <NUM>. The nacelle <NUM> encloses the case <NUM> and defines therebetween a fire-protected space <NUM>. The case <NUM> in turn encloses the compressor <NUM>, the combustor <NUM>, and the turbine <NUM>, along with other components of the gas turbine engine <NUM>. The compressor <NUM> is operably associated with and connected to the turbine <NUM>. The compressor <NUM> is in fluid communication with an ambient environment and is configured to generate a working fluid flow <NUM> using work provided by the turbine <NUM>. The combustor <NUM> is in fluid communication with the compressor <NUM> and is arranged to generate a high pressure combustion product flow <NUM> using the working fluid flow <NUM>. The turbine <NUM> is in fluid communication with the combustor <NUM> and is arranged to extract work from the high pressure combustion product flow <NUM> received from the combustor <NUM>, a portion of which the turbine <NUM> communicates to the compressor <NUM> as work.

The fire and overheat detector system <NUM> includes one or more sensor elements <NUM>, one or more support brackets <NUM>, and one or more support rails <NUM>. The support brackets <NUM> and the support rails <NUM> may be configured to connecting to and/or mounting to the case <NUM> of the gas turbine engine <NUM>. In some configurations, the support rails <NUM> are mounted to the support brackets <NUM> and the support elements <NUM>, <NUM> supports the sensor elements <NUM>. The sensor elements <NUM> may be, in some embodiments and configurations, wires or cables that extend over a designated section of the gas turbine engine <NUM>. The sensor elements <NUM> may thus be arranged to monitor temperatures and thus potential for overheat and/or fire within such sections of the gas turbine engine <NUM> (e.g., fire-protected space <NUM>).

As shown in <FIG>, the fire and overheat detection system <NUM> may be arranged and configured as a continuous fire and overheat detection system. In this respect, the support elements <NUM>, <NUM> may include multiple instances to arrange the fire and overheat detection system <NUM> within and along the fire-protected space <NUM>. Although the fire and overheat detection system <NUM> is shown as a continuous system in the illustrated embodiment, it is to be understood and appreciated that spot-type fire and overheat detection systems can also benefit from aspects of embodiments of the present disclosure.

As will be appreciated by those of skill in the art in view of the present disclosure, the case <NUM> of the gas turbine engine <NUM> communicates heat to the fire-protected space <NUM> during operation. To detect an overheating of the gas turbine engine <NUM>, the fire and overheat detection system <NUM> is operably connected to the gas turbine engine <NUM>. The fire and overheat detection system <NUM> is arranged, at least partially, within the fire-protected space <NUM> and includes the one or more sensor elements <NUM> arranged to detect a temperature within the fire-protected space <NUM>. In this illustrative configuration, the support brackets <NUM> may be connected to or mounted to an exterior surface of the case <NUM> of the gas turbine engine <NUM>. The fire and overheat detection system <NUM> may be continuous and extend within and/or through the fire-protected space <NUM>. The sensor elements <NUM> may be mechanically damped from vibration communicated by the gas turbine engine <NUM> by the support brackets <NUM> and/or the support rails <NUM>. The sensor elements <NUM> are configured to monitor a temperature of the case <NUM>, e.g., via resistivity change of a thermistor body contained within the sensor elements <NUM>.

It will be appreciated that the fire and overheat detection systems are installed on or at key fire hazard areas in an engine or an aircraft auxiliary power unit (APU). In some cases, the locations where these are installed may be exposed to a combination of fluids from the engine/APU and external contaminants that enter the compartment though the various openings in the compartment. These fluids can combine into detrimental mixtures that can result in corrosion to the aircraft and/or the fire detectors installed in the compartment(s) of the engine/APU. In operation the compartments to be monitored may be exposed to, for example and without limitation, fuels, oils, anti-ice fluids, acidic salt fog, and combinations thereof. As such, the fire and overheat detection systems or components thereof may also be subject to exposure to such chemicals and substances. Moreover, the fire and overheat detection systems may be exposed to <NUM> °F (<NUM>) or greater (e.g., <NUM> °F (<NUM>) or greater), and thus high temperature rating may be required.

As noted, the fire and overheat detection systems may include wires that connect to detectors and these wires or the detectors themselves may become corroded by such fluids. The wiring of the fire and overheat detection systems may be operably and electrically connected to a controller or to another sensor/detector in a sensing loop of a fire and overheat detection system. In a given installation, there may be anywhere from one to several detectors connected in series.

In operation, the sensing elements of the fire and overheat detection systems of the present disclosure typically or normally at a high resistance state. When exposed to a fire condition, the resistance of the sensing element decreases as the temperature increases. The resistance of the sensing elements may be preset such that specific temperatures may indicate an alarm threshold temperature. When the alarm threshold temperature is met or exceeded, a connected controller or monitoring electronic system can activate a fire alarm and/or fire suppression system.

The corrosion that can form can bridge the insulating portions of the sensors, causing faulty and/or unnecessary alarms or suppression system activation. For example, the corrosion may bridge across a ceramic separator portion, which can result in a significant resistance drop. This resistance drop caused by the corrosion can appear to the sensor as a resistance drop expected in a fire situation. The change in resistance from corrosion can result in a false alarm or a fault. In aircraft applications, such faults or false alarms may give rise to emergency situations, where an aircraft may be required to land to ensure that no actual fire is present. Accordingly, embodiments of the present disclosure are directed to aircraft fire and overheat detection system having improved sensor protection.

Turning now to <FIG>, a schematic illustration of an aircraft fire and overheat detection system <NUM> having a sensor assembly <NUM> in accordance with an embodiment of the present disclosure is shown. The sensor assembly <NUM> includes a sensing element <NUM> that extends between two terminal assemblies 206a, 206b. The sensing element <NUM> may be a wire or cable, as will be appreciated by those of skill in the art. The terminal assemblies 206a, 206b each include a flange 208a, 208b and a connection assembly 210a, 210b. The connection assembly 210a, 210b of each terminal assembly 206a, 206b includes a threaded barrel 212a, 212b, an insulator 214a, 214b, a terminal cap 216a, 216b, a connection cable 218a, 218b, and a terminal lug 220a, 220b for connecting the connection assembly 210a, 210b to the connection cable 218a, 218b. The connection cable 218a, 218b is configured to electrically and operably connect to a controller, processor, or other system that monitors the electrical properties of the aircraft fire and overheat detection system <NUM>. The terminal lugs 220a, 220b in some configurations can include a screw, nut, and washer, although other connection configurations are possible without departing from the scope of the present disclosure.

The aircraft fire and overheat detection system <NUM> may be mounted to an aircraft engine structure or other aircraft structure by affixing the aircraft fire and overheat detection system <NUM> to one or more brackets 222a, 222b. As shown, in this non-limiting embodiment, the connection assemblies 210a, 210b include a mounting head 224a, 224b and a mounting nut 226a, 226b. The brackets 222a, 222b may be arranged between these two components of the connection assemblies 210a, 210b. The mounting nut 226a, 226b of the connection assemblies 210a, 210b may be threaded on the threaded barrel 212a, 212b of each terminal assembly 206a, 206b to secure the terminal assembly 206a, 206b to the brackets 222a, 222b.

In operation, the sensing element <NUM> is responsive to temperature changes and in such changing temperatures the resistance of electrical current through the sensing element <NUM> will change. The connection cables 218a, 218b are configured to convey information associated with the change in resistance in order to detect an increase in temperature that may be indicative of an overheat or fire situation. The insulator 214a, 214b is provided to minimize external factors (e.g., conductive fluids or materials) from impacting the sensing capability of the aircraft fire and overheat detection system <NUM>. The insulator 214a, 214b may also provide insulation of an electrical signal from a grounded surface. If a conductive path from the sensing element <NUM> becomes grounded, false alarms or improper detection may arise, and thus preventing the sensing element <NUM> from improper grounding is important to ensure proper operation of the aircraft fire and overheat detection system <NUM>. Specifically, for example, it may be preferred to avoid grounding of the terminal cap 216a, 216b and/or the terminal lug 220a, 220b. Exterior grounding (e.g., a sensor outer tube) may be acceptable, as such grounding may not impact the sensing device in a negative manner. However, to avoid false alarms or the like, the interior grounding should be avoided.

For example, if a fluid or liquid passes over the connection assemblies 210a, 210b it can cause corrosion of one or more components of the connection assemblies 210a, 210b. This fluid can cause an electrical bridge or grounding across the insulator 216a, 216b, thus impacting the ability of the connection cables 218a, 218b to detect an accurate resistance of the sensing element <NUM>. This can lead to false alarms or false detection of overheat or fire situations. As such, it may be advantageous to have improved protection of the components of the aircraft fire and overheat detection system <NUM>, and thus improve detection reliability and accuracy.

Embodiments of the present disclosure are directed to aircraft fire and overheat detection systems that include a protective sleeve that is configured to prevent fluids or liquids from causing corrosion to the components of the aircraft fire and overheat detection system. For example, the protective sleeves of the present disclosure are configured to be applied to the terminal assemblies of an aircraft fire and overheat detection system such that the electrical components are protected and environmental impacts on the electrical sensing of such systems may be minimized or eliminated.

Turning now to <FIG>, schematic illustrations of an embodiment of the present disclosure are shown. <FIG> illustrates a protective sleeve <NUM> for use with an aircraft fire and overheat detection system and <FIG> illustrates the protective sleeve <NUM> as installed to a portion of an aircraft fire and overheat detection system. Specifically, <FIG> illustrates the protective sleeve <NUM> as applied about a portion of a terminal assembly <NUM> of an aircraft fire and overheat detection system.

The protective sleeve <NUM> has a substantially tubular shape with a lug portion <NUM> and a wire portion <NUM>. As shown, the lug portion <NUM> has a larger or increased diameter or size relative to the wire portion <NUM>. The protective sleeve <NUM> is made from a material that is capable of withstanding relatively high heats in aircraft engine or aircraft environments and is non-reactive with the components of the terminal assembly <NUM> of an aircraft fire and overheat detection system. For example, materials of the protective sleeve <NUM> can include, without limitation, polyolefin, fluoropolymer, polyvinyl chloride (PVC), polychloroprene (neoprene), silicone elastomer, etc. The material may be selected for resiliency and elasticity in order to provide a tight and secure forming fit about components of the terminal assembly <NUM> of an aircraft fire and overheat detection system. The material of the protective sleeves of the present disclosure may be selected to withstand temperatures in excess of <NUM> °F (<NUM>). In some embodiments, the material may be selected to withstand temperatures of <NUM> °F (<NUM>) or greater, and still further, in some embodiment, the material may be selected to withstand temperatures of <NUM>,<NUM> °F (<NUM>,<NUM>). In other embodiments, the material may be selected as a sacrificial element that will be destroyed in the event of an actual fire or high temperature event. That is, the material may be selected to protect and maintain such protection during normal operation and normal operational temperatures but may be sacrificed in the event of an actual fire or overheat event. The material is thus selected to survive and protect the components of the sensor during normal operation to avoid false activation and/or grounding of the sensor components that are protected by the protective sleeve <NUM>.

The protective sleeve <NUM> includes a lug area <NUM> at the lug portion <NUM> that is an interior cavity or region that is sized and shaped to receive various components of the terminal assembly <NUM> of an aircraft fire and overheat detection system. The lug portion <NUM> has a first inner diameter D<NUM> that is sized and shaped to receive the components of the terminal assembly <NUM>. Proximate a first end <NUM> of the protective sleeve <NUM>, of the lug portion <NUM>, is a sealing protrusion <NUM>. The sealing protrusion <NUM>, in this non-limiting embodiment, is a V-shaped structure that extends radially inward from an interior surface of the lug portion <NUM> of the protective sleeve <NUM>. It will be appreciated that in other embodiments, the sealing protrusion <NUM> may have other geometric profiles, such as rounded, squared, multiple ridges, and the like, without departing from the scope of the present disclosure. The geometric shape of the sealing protrusion <NUM> may be selected to ensure and optimize a sealing contact between the protective sleeve and the terminal assembly <NUM> in the lug portion <NUM>. The sealing protrusion <NUM> defines a section of the lug portion <NUM> that has a reduced diameter proximate the first end <NUM> of the protective sleeve <NUM>.

In a direction from the first end <NUM> (e.g., lug portion <NUM>) toward a second end <NUM> (e.g., wire portion <NUM>) is a first transition portion <NUM>. The first transition portion <NUM> is a tapering structure that reduces the diameter of the protective sleeve <NUM> in a direction from the first end <NUM> toward the second end <NUM>. Specifically, the first transition portion <NUM> defines a tapering diameter from the first diameter D<NUM> of the lug portion <NUM> to a second diameter D<NUM> of a first wire portion <NUM>. The tapering dimensions of the first transition portion <NUM> may has a size and axial length to accommodate hardware that secures a connection wire/cable to a lug or other component of the terminal assembly <NUM>. The first wire portion <NUM> is configured to fit about, and contact, an exterior surface of a connection cable of the terminal assembly <NUM>.

The first wire portion <NUM> is followed by a second transition portion <NUM>. The second transition portion <NUM> is a tapering structure that reduces the diameter of the protective sleeve <NUM> in a direction from the first end <NUM> toward the second end <NUM>. Specifically, the second transition portion <NUM> defines a tapering diameter from the second diameter D<NUM> of the first wire portion <NUM> to a third diameter D<NUM> of a second wire portion <NUM>, which extends to the second end <NUM> of the protective sleeve <NUM>. The third diameter D<NUM> is sized to provide an interference fit with a portion of an exterior surface of a connection cable of the terminal assembly <NUM>, as described below. In additional to the mechanical fit and surrounding of the components of the terminal assembly <NUM>, the protective sleeve <NUM> can include an optional adhesive sealant on a portion or the entire interior surface <NUM>. The adhesive sealant can be, for example and without limitation, hot-melt, silicone, elastomers, epoxy, etc..

The protective sleeve <NUM> defines an interior bore <NUM> that is open at the first end <NUM> and the second end <NUM> with a continuous bore or cavity extending between the two ends <NUM>, <NUM>. The interior bore <NUM> is sized and shaped to receive the terminal assembly <NUM> and the components thereof. The described diameters D<NUM>, D<NUM>, D<NUM> and the transition portions <NUM>, <NUM> reflect the interior shape and size of the protective sleeve <NUM>.

<FIG> illustrates the terminal assembly <NUM> as installed within the protective sleeve <NUM>. As shown, the terminal assembly <NUM>, similar to that shown and described above, includes a flange <NUM> connected to a sensing element <NUM> and a connection assembly <NUM>. The connection assembly <NUM> includes a threaded barrel <NUM>, a mounting nut <NUM> threaded onto the threaded barrel <NUM> that combines with a mounting head <NUM> to connect to a bracket <NUM>, an insulator <NUM>, a terminal cap <NUM>, a terminal lug <NUM>, and a connection cable <NUM>. The majority of the components of the connection assembly <NUM> fit within the lug portion <NUM> of the protective sleeve <NUM>. The first transition portion <NUM> fits about the terminal lug <NUM> and reduces to the second diameter D<NUM> where the connection cable <NUM> extends from the terminal lug <NUM>. In some embodiments, the protective sleeve <NUM> may be heat shrinkable about the components of the terminal assembly <NUM>. As such, a pre-installation size/dimension of the protective sleeve <NUM> may be sized to fit or slide over the terminal assembly <NUM>, and then heat is applied to shrink or form-fit the protective sleeve <NUM> about the terminal assembly <NUM>. The heat application may cause the end result of a bonding form-fitting or a reduced diameter protective sleeve that forms essentially an interference fit with the exterior surfaces of one or more of the components of the terminal assembly <NUM>.

Along the length of the first wire portion <NUM>, the interior surface <NUM> of the protective sleeve <NUM> will contact and bond with the exterior surface of the connection cable <NUM>. In some embodiments, the interior surface <NUM> may include an adhesive sealant, as discussed above, which aids in the bonding of the protective sleeve <NUM> to the terminal assembly <NUM>. For example, such adhesive sealant can, in some embodiments, enable the bonding of the protective sleeve <NUM> to the connection cable <NUM>. Further, in some embodiments, the second diameter D<NUM> may be sized to provide an interference fit with the connection cable <NUM>. Toward the second end <NUM> of the protective sleeve <NUM>, the second transition portion <NUM> reduces the diameter of the interior bore <NUM> to the third diameter D<NUM> such that a greater interference fit between the protective sleeve <NUM> and the connection cable <NUM> is achieved. In some embodiments, the second diameter D<NUM> may be selected to be about the same size/diameter as an external diameter of the connection cable <NUM> and the third diameter D<NUM> may be selected to be less than the size/diameter as an external diameter of the connection cable <NUM>.

As shown in <FIG>, the sealing protrusion <NUM> is positioned and captured between the bracket <NUM> and the mounting nut <NUM> threaded onto the threaded barrel <NUM>. The sealing protrusion <NUM> is a protrusion of the material of the protective sleeve <NUM> that can be captured or pressed between the mounting nut <NUM> and the surface of the bracket <NUM>. The material of the sealing protrusion <NUM> provides for a complete fluid seal at the first end <NUM> and prevents fluid or liquid intrusion into the interior bore <NUM> of the protective sleeve and thus prevents any such fluid or liquid from compromising the electrical stability and functionality of the aircraft fire and overheat detection system.

Advantageously, embodiments of the present disclosure provide for improved aircraft fire and overheat detection systems having protection from the environmental conditions when operated onboard an aircraft. Due to the nature of the location necessary for aircraft fire and overheat detection systems on aircraft, the components thereof may be subject to high vibrations, chemical exposures, and drastic temperature changes. These environmental conditions can lead to corrosion or other damage or impact to aircraft fire and overheat detection systems. Embodiments of the present disclosure provide for a protective sleeve that protects the components of the aircraft fire and overheat detection system in such harsh conditions.

As used herein, the terms "about" and "substantially" are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, the terms may include a range of ± <NUM>%, or <NUM>%, or <NUM>% of a given value or other percentage change as will be appreciated by those of skill in the art for the particular measurement and/or dimensions referred to herein.

It should be appreciated that relative positional terms such as "forward," "aft," "upper," "lower," "above," "below," "radial," "axial," "circumferential," and the like are with reference to normal operational attitude and should not be considered otherwise limiting.

Claim 1:
An aircraft fire and overheat detection system (<NUM>), comprising:
a support bracket (<NUM>) configured to secure the aircraft fire and overheat detection system to a component of an aircraft;
a terminal assembly (<NUM>) fixedly connected to the support bracket (<NUM>), the terminal assembly (<NUM>) comprising a connection assembly (<NUM>) and a connection cable (<NUM>), wherein the connection assembly (<NUM>) comprises a mounting nut (<NUM>) threaded onto a threaded barrel (<NUM>) and a mounting head (<NUM>), wherein a portion of the support bracket (<NUM>) is secured between the mounting nut (<NUM>) and the mounting head (<NUM>);
a sensing element (<NUM>) electrically connected to the terminal assembly (<NUM>) and arranged to detect at least one of fire and heat associated with the component of the aircraft, wherein the connection cable (<NUM>) is electrically connected to the sensing element (<NUM>) to enable detection of an electrical resistance in the sensing element (<NUM>); and
a protective sleeve (<NUM>) arranged about the connection assembly (<NUM>) and connection cable (<NUM>), the protective sleeve (<NUM>) comprising a first end (<NUM>) having an opening and a second end (<NUM>) having an opening and an interior bore (<NUM>) extending between the openings at the first and second ends (<NUM>,<NUM>), wherein:
a lug portion (<NUM>) is arranged at the first end (<NUM>) and includes a sealing protrusion (<NUM>) extending radially inward within the interior bore (<NUM>), the lug portion (<NUM>) having a first diameter (D<NUM>), wherein the interior bore (<NUM>) of the lug portion (<NUM>) is sized to receive the connection assembly (<NUM>) and the sealing protrusion (<NUM>) is positioned and captured between the support bracket (<NUM>) and the mounting nut (<NUM>), the sealing protrusion (<NUM>) sealingly engaging between the threaded nut (<NUM>) and the portion of the support bracket (<NUM>),
a first wire portion (<NUM>) having a second diameter (D<NUM>) that is less than the first diameter (D<NUM>) and extending toward the second end (<NUM>), and
a second wire portion (<NUM>) arranged at the second end (<NUM>), the second wire portion (<NUM>) having a third diameter (D<NUM>) that is less than the second diameter (D<NUM>), wherein the third diameter (D<NUM>) is sized to provide an interference fit with a portion of the connection cable (<NUM>).