The present invention generally relates to electrical connectors.
More specifically, the present invention relates to electrical connector housings for connecting a cable lug to a threaded terminal by means of a screw.
In order to connect a plurality of cable lugs to threaded electrical terminals an electrical connector is generally used which has a housing with openings for the passage of cables and openings for electrically connecting the cable lugs to the threaded terminals using screws.
The housings also have openings opposite the terminal openings for inserting and tightening these cable lug retention screws to the terminals.
Generally, in the field of electrical connectors, and in the field of high-voltage electrical connectors in particular, it is necessary to provide maximum protection of individuals against contact with electrical parts under voltage.
At the same time, the tightness of connectors must be provided in certain applications, notably in electric propulsion vehicles. In particular, when the housing is closed this involves ensuring that each channel of the connector is isolated in a sealed manner relative to the other connector channels in order to prevent a short circuit between the channels in the event of water ingress in the housing.
Numerous devices of this type are known which provide protection of individuals against electrical risks, whilst keeping the contacts isolated from the outside in a sealed manner.
In particular, a connector housing is known to this end which has an overall parallelepipedic shape forming a chamber for the lugs with lateral openings for the passage of electrical cables which terminate with lugs, and openings to a surface which is essentially perpendicular to the preceding surface for contacting the lugs with the terminals. The surface opposite the surface which has the openings for terminals is fully open to allow access to the chamber for installation and tightening of the screws to the threaded terminals. A cover which is retained by screws covers up this surface. Each opening is provided with a seal. The cover has a seal on its internal surface and sealed partition walls designed to partition off each channel inside the chamber in a sealed manner once the cover is closed.
In this type of housing, a contact device is provided for the protection of individuals, which contact device controls the cut-off of current upstream of the connector when the cover is removed. In general, this contact device is a micro-switch or two contact parts mounted to the housing and its cover respectively, which open an electrical circuit when the cover is open. However, this device may sometimes fail.
In effect, when the cover is removed the screws are directly accessible and in the event of the failure of the current cut-off device the screws continue to be supplied with current and this constitutes a risk to individuals.
Furthermore, once the cover is removed the seal between the channels is no longer provided.
Finally, this type of housing has numerous parts which make it costly in terms of manufacturing and onerous to assemble.
As a result of these observations, the general purpose of the present invention is to perfect electrical connector housings for connecting a cable lug to a threaded terminal in a known electrical device.
More specifically, the purpose of the invention is to provide a housing offering a high degree of protection for individuals by improving the channel-to-channel tightness of known solutions, whilst being simple, reliable and of robust construction and economic to manufacture, assemble and disassemble.
To this end, the invention proposes an electrical connector housing for connecting at least one cable lug to a threaded terminal of an electrical device, including, for each lug, a hole for receiving a screw for retaining a lug in a threaded terminal, which hole has a lateral slot designed to allow a lug to penetrate the hole, a lower opening for connecting the lug to a threaded terminal and an upper opening designed to allow the passage of a screwing tool for the screw, the size of the upper opening of the hole at its widest point being strictly less than the size of the hole at its widest point, said opening being designed so as to allow the passage of the screwing tool and having a section which is less than the section of a human finger.
The term human finger is understood to be a finger which has a diameter of at least 12 mm and a radius at its tip of approximately 4 mm, which essentially corresponds to the size of an average human finger.
In this way, and advantageously, the protection of individuals is vastly improved as, according to the invention, it is impossible for a human finger to make contact with a part under voltage. Furthermore, during disassembly, the screw cannot exit the hole via the upper opening or via the lower opening as long as the lug remains inside the hole: this reduces the risk of losing the screw during interventions on the housing.
Furthermore, channel-to-channel tightness is facilitated by the design of the housing according to the invention in so far as each lug is placed into a different hole independently. If a hole is flooded the other holes will not be affected, even if the cover is removed.
These provisions have an advantageous effect in terms of the reliability of the housing according to the invention.
According to advantageous features, possibly combined:
The protection of individuals is thus improved and obtaining tightness is facilitated.
According to advantageous features, possibly combined:
It can be seen that, even in the event of a failure in the current cut-off device, when the housing according to the invention is opened the risks to individuals are very limited as it is impossible for a finger to be inserted via the upper opening in the hole.
According to advantageous features, possibly combined:
Also, advantageously, once disconnected the housing continues to effectively ensure the protection of individuals, since even if a finger is inserted into the lower opening there is no risk of an electric shock as it will encounter an insulating element.
According to an advantageous aspect:
This provision advantageously reduces the costs of this device.
The invention further proposes, according to a second aspect, a process of connecting an electrical connector for connecting at least one cable lug to a threaded terminal of an electrical device including a housing as previously described, including steps consisting in:
The invention will be further explained by means of a detailed description of an embodiment, which is provided hereafter for illustrative and non-limiting purposes, with reference to the appended drawings, wherein:
As can be seen in
As can be seen more specifically in
The housing 1 allows the connection of a lug 31 to a threaded terminal 41 of the electrical device 4 to be connected.
Conventionally, the lug 31 is crimped to the end of the cable and has a connection ring 32.
The housing 1 has a hole 11 for each lug for receiving a retention screw 12. The hole 11 has a lateral slot 13 designed to allow the ring 32 of the lug to penetrate the hole.
The hole also has a lower opening 14 for connecting the lug to the threaded terminal 41 and an upper opening 15 designed to allow the passage of a screwing tool for the screw 12.
The diameter of the upper opening 15 of the hole is strictly below the diameter of the hole. The opening 15 is delimited by a collar 16 provided at the upper end of the hole.
In practice, the size of the upper opening of the hole at its widest point is less than or equal to 12 mm, which is sufficient to allow the passage of the tip of a screwing tool but effectively prevents an individual from inserting a finger into the hole.
The cover 6 is provided with seals 61 designed to sit in grooves 17 provided around the collars 16 to close each hole individually in a sealed manner.
The overall tightness is improved compared to the prior art, as when a single hole is flooded water cannot pass from one hole to another, even when the cover 6 is removed.
The lower opening 14 of the hole 11 has a specific seal 18 designed to co-operate with the device 4.
As can be seen more specifically in
In this way, the cover 6 maintains the housing 1 in a sealed manner against the device 4 by means of the seals 18 of each hole 11.
In a manner per se known, the cover has contact means designed to ensure that the current upstream of the connector is cut-off of when the cover is removed. This contact means is a metal ring 63 joined to the cover cooperating with a metal plate 43 mounted to the device to be connected. Opening of the cover causes the separation of the two metal elements and thus the opening of an electrical circuit which controls the cut-off of the current upstream of the connector.
As can be seen in
The plug is constituted by a shell 81 which has two lobes 82 which are snapped on to two conforming tabs 72 provided to this end on the external surface of the channel 7. Inside the shell a seal 83 ensures tightness between the cable 3 and the channel 7.
In a manner per se known, the channel 7 has a shielding transmission zone 73 between the shielding cover of the cable 3 and the housing 1. In a manner well known to a person skilled in the art, the housing 1 is made from plastic material which is selectively metallised to provide continuity of the shielding.
As can be seen more specifically in
Around the zone 73, the shielding cover of the cable 3 makes contact with the internal metal layer 74, as can be seen in
This metal layer merges into an external metal layer 76 which extends along the external surface of the channel 7 up to the shoulder 77.
The continuity of the shielding on the channel 7 is provided by the cover 6, which is made from metal material.
This can be seen more clearly in
The external metal layer 76 extends up to the shoulder 78 to the base of the hole 11, covering the edge 79.
The continuity of the shielding between the channel 7 and the metal cover of the electrical device 4 to be connected is made by means of the metal edge 79. This is more specifically visible in
A further embodiment is shown in
Thus, the metallisation is ended on the channel 7 before the seals 71, 18 and 61. In this way, if the internal space of the channel 7 defined between these seals is flooded there is no line of current between the shielding and the conducting elements.
A portion of cable 3 provided with a lug 31 with a ring 32, according to the invention, is shown in
A connector plug 5 is provided for the interface between the cables and the housing, it has two seals 83 and 71 and two lobes 82, as previously described.
As can be seen more specifically in
In this way, the screw is maintained between the end of the hole 11 which has the upper opening 15 and the slot 13, so as to keep the screw spaced apart from the slots and thus allow the insertion of the lug, as can be seen more specifically in
In practice, when using a connector provided with a housing according to the invention, this involves in the first instance the introduction of the retention screw 12 via the lower opening 14 by presenting the tip towards the upper opening, until it passes over the protrusions 19. The screw is maintained above the slot 13 and the lug 31 is inserted into the hole via said slot.
As can be seen in
Using a screwing tool (not shown) inserted via the upper opening 15, the screw 12 is pushed beyond the protrusions 19 and engages in the thread of the terminal 41. The lug is subsequently tightened to the terminal and the screwing tool is removed. In a final step, the cover 6 is installed and tightened via the ring 62, which can be seen in
Moreover, in the embodiment shown in
In this way, even when the connector is disconnected from the device it maintains a high degree of safety and the possible insertion of a finger into the lower opening 14 does not constitute a risk as the first element encountered will be the insulating cap 21.
The invention is not limited to the examples of lugs as previously described but, on the contrary, covers all types of known lugs, such as, for example, “U” plate lugs and strong section “U” or “0” round lugs.
In general, numerous other variants are possible as a function of circumstances, and it should be noted in this respect that the invention is not limited to the examples described and shown.
Number | Date | Country | Kind |
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0958278 | Nov 2009 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2010/066910 | 11/5/2010 | WO | 00 | 5/22/2012 |