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(11) | EP 0 247 006 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A blade connector structure for electrical apparatus |
| (57) A blade connector structure (1) for the formation, in an extremely simple and rapid
manner, of the connection of an electrical appliance both to a supply cable (2) and
to an earthing point. The blade connector structure (1) essentially comprises an elongate
body (2) made of insulating material, provided with an elongate axial median projection
(3) extending from one end and on either side of which are fixed corresponding connecting
conductor elements (5) each having a pair of blade contacts. Spaced from these conductor
elements on the insulating body (2) is fixed a suitably shaped small metal plate (9)
provided with means (10, 11) for retaining the earthing wire (12) and means (13, 20)
for its anchorage to the casing (18) of the appliance to which it is fitted. |
[0001] The present invention relates to a blade connector structure which can be fitted to an electrical appliance, in particular to a domestic electrical appliance incorporating an attachment by which preliminary connection of the supply cable and earthing of the metal casing thereof can be achieved.
[0002] As is known, to avoid the possible risks of electrocution domestic electric apparatus in general requires an effective earthing connection of the metal housing or casing. For this purpose there is currently generally provided on the casing itself a captive screw or the like to which the terminal part of the earthing wire is anchored by means of a nut and an associated washer. The said arrangement obviously can involve some difficulties for its correct performance, and furthermore involves not insignificant times for connection of the said earthing wire.
[0003] The object of the present invention is that of eliminating the previously indicated disadvantage by providing a blade connector structure which is able to simplify the supply and, in particular the connection between the casing of an electrical appliance and the earth connection in the greatest possible manner.
[0004] According to the present invention, there is provided a blade connector structure for connecting an electrical supply cable to the internal wiring of an electrical appliance, characterised in that it comprises an elongate body of insulating material having at one end an elongate projection extending axially and lying in a longitudinal median plane to either side of which are fixed respective conductive connector elements each having blade contacts, and spaced from which, on the body there is fixed a shaped metal plate provided with means for retaining an earthing wire and means for electrical connection thereof to the casing of the electrical apparatus to which the connector is to be fitted.
[0005] A particular advantage of the invention is that of providing a blade connector structure which allows the preliminary connection of the supply cable, complete with the said earthing cable to be effected.
[0006] Another advantage of the present invention is that of providing a blade connector structure which is easy to fit with a minimum of substantially elementary operations from the outside of the casing of a domestic electrical appliance or the like. A further advantage of the present invention is that of providing a blade connector structure which is constructionally simple and of great reliability.
[0007] Two embodiments of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which:
Figure 1 is a schematic side view of a connector structure formed as an embodiment of the invention;
Figure 2 is a plan view from above of the same connector structure;
Figure 3 is a plan view from below of the same connector structure;
Figures 4 and 6 are two exemplary apertures which may be formed on the metal casing of apparatus to be supplied with electricity, for receiving the structure of the present invention;
Figure 5 is a rear view of the same structure when fitted in an aperture such as that illustrated in Figure 4 and connected to the said casing; and
Figure 7 is a plan view from above of a second embodiment of the invention.
[0008] Referring now to the drawings, the connector structure of the invention, generally indicated 1, comprises a body 2 of insulating material having an elongate conformation with a flat plate-like longitudinally extending projection 3 at one end lying in a median axial plane, and a generally disc-like transversely enlarged head portion 4 at the other end with a central coaxial aperture for receiving an electrical connector cable 21 of conventional 3-core type having two current-carrier wires 16 and an earthing wire 12.
[0009] This elongate body is shaped in such a way as to define, on opposite sides of the said median projection 3, corresponding seats to receive blade contacts 5 to which the current-carrier wires 16 are connected by means of a clamping screw 6. On the same elongate body 2 there is formed a substantially flat portion 7 provided with elastically deformable upwardly extending projections 8 which are able to retain a metal plate 9 provided with corresponding apertures 10. This plate, in particular, has a threaded hole for the engagement of a clamping screw 11 for forming an electrical connection between the earthing wire 12 and the small plate 9 itself. This plate, moreover, is provided with one or more right angle projections 13 provided with special small teeth having an enamel-breaking formation to make certain of the earthing contact to the casing of the apparatus the exterior of which is usually coated in enamel or other protective coating. The said right angle projections 13 extend orthogonally of the axis of the body 2 generally tangentially of the disc-like head end portion 4 thereof. In the region adjacent the head end 4 of the body 2 this latter has a substantially rectangular or oval transverse section matching the shape of an aperture 17 in a panel 18 of the casing of the electrical appliance to which the connector is to be fitted as shown in Figures 1,2 and 5. In practice, the connector 1, with the supply cable 21 preliminarily fitted thereto and the earth wire 12 connected to the plate 9 by the screw 11, is inserted into the aperture 17 in the casing 18 of the domestic electrical appliance.
[0010] The panel 18 is also formed with two through-holes 19 to receive the shanks of corresponding, preferably self-tapping screws 20 by which the right angle brackets 13 of the small plate 9 can be connected to the casing panel 18 thereby securing the connector 1 to the panel 18 and at the same time connecting the earth wire 12 to the casing panel 18.
1. A blade connector structure for connecting an electrical supply cable (21) to the
internal wiring of an electrical appliance, characterised in that it comprises an
elongate body (2) of insulating material having at one end an elongate projection
(3) extending axially and lying in a longitudinal median plane to either side of which
are fixed respective conductive connector elements (5) each having blade contacts,
and spaced from which, on the body (2) there is fixed a shaped metal plate (9) provided
with means (8,10,11) for retaining an earthing wire (12) and means (13,20) for electrical
connection thereof to the casing (18) of the electrical apparatus to which the connector
(1) is to be fitted.
2. A blade connector structure according to Claim 1, characterised in that the said
elongate body (2) has at the opposite end from the said elongate projection (3) an
enlarged disc-like head portion (4), and in that there are clamping means (5) for
connecting the ends of current-carrier wires (16) to the said blade contacts, the
said elongate body (2) having a substantially flat portion (7) provided with resiliently
deformable upwardly extending projections (8) which are able to retain a metal plate
(9) provided with corresponding apertures (10).
3. A blade connector according to Claim 1 or Claim 2, characterised in that the said
plate (9) has a threaded hole for engagement of a clamping screw (11) for forming
an electrical connection between the said earthing wire (12) and the said plate (9)
itself; the said means (13,20) for electrically connecting the plate (9) to the said
casing (18) comprising one or more right-angle projections (13) of the said plate
(9) having holes therethrough for receiving fixing screws (20) by which the plate
(9) can be fixed mechanically to the casing (18).
4. A blade connector structure according to any preceding Claim, characterised in
that the said insulating body (2) has adjacent the disc-like head end portion (4)
a part having a substantially rectangular transverse section from opposite faces of
which project respective resiliently deformable teeth (15).
5. A blade connector structure according to any preceding Claim, characterised in
that the said means (13,20) for electrically connecting the said plate (9) to the
casing (18) of an electrical appliance includes shaped teeth having an enamel-breaking
function.
6. A blade connector structure according to any of Claims 3, 4 or 5, characterised
in that the said metal plate (9) is provided with two tongues (13) bent at 90° to
the plane of the plate and lying close to a threaded hole in which the earthing wire
(12) is anchored.
7. An electrical appliance provided with a blade connector structure according to
any preceding Claim, characterised in that the appliance has a casing panel (18) with
an aperture (17) shaped to receive the body (2) of the connector structure (1) and
two through-holes (19) closely adjacent the said aperture (17) to receive the shanks
of corresponding self-tapping screws whereby the said metal plate (9) is connected
to the casing panel (18) itself.
8. An electrical appliance according to Claim 7, characterised in that the said aperture
(17) in the casing panel (18) has two diametrically opposed cavities to allow insertion
and removal of the body (2) of the connector (1) from outside the appliance.