CN1747241A - Electric connector - Google Patents

Abstract

The invention comprises an annular groove, an annular contact piece and electric contact located in annular groove above, which can establish electric contact with annular contact piece above. A limiting piece is mounted near contact piece in annular groove that makes part of groove narrower than other part of groove.

Description

Electric connector

Technical Field

The present invention relates to electrical connectors and, in particular, to such connectors which may be engaged irrespective or substantially irrespective of their relative angular position. The invention is particularly, but not exclusively, applicable to connectors of the type used on liquid heating vessels.

Background

The so-called 360 degree connectors of kettles and jugs are well known to those skilled in the art. In the most popular form of Strix P72 of this type of connector, the wireless device is provided with a centerline contact and two concentric annular conductors underneath it. The smaller diameter conductor is used for the neutral of the ac power supply and the outermost conductor is used for the ground connection. The base of the corresponding connector is provided with a central hole for the wire connection, surrounded by an annular groove that can receive a neutral ring. The electrical connection is made by resilient contacts located in the base connector portion and a portion of the annular groove, respectively, below the bore, the contacts being biased against the wire connector and the neutral ring, respectively. The base connector part may be secured in the outermost grounding ring of the equipment connector part and provided with an outwardly directed resilient contact on one side for engaging the inner surface of the grounding ring. Further details of such a connector are given in international patent application 95/08204.

It is clear that in order to make such a connection system safe it is necessary to ensure that the user cannot accidentally touch the live electrical contacts, and that the connector described above does so by making the hole and the annular groove sufficiently narrow that even a child's finger cannot enter. For this reason, an international standard specifies the maximum width, which the above-mentioned connectors easily meet. While meeting this standard is not necessary, the P72 cordless connector also implements a further safety code standard, i.e., it does not allow any item in ordinary household cutlery, such as a knife tip or teaspoon handle, to be inserted into a hole or slot to contact the contacts. The curvature and narrow width of the annular hole in P72 ensures this.

The applicant has recently proposed in PCT/GBO0/03901, which was unpublished at the date of this application, to provide a 360 degree connector with an additional annular groove (and corresponding additional annular conductor on the device portion of the connector) to provide an additional electrode, such as a temperature control that can connect a pair of thermal sensors on the device to the base portion. Since the initial annular groove is the same diameter as before, the two other outer grooves are necessarily larger. Thus, a slower bend means that while the slot is still narrow enough to meet international safety standards, there is a greater chance that the additional test standards mentioned above cannot be passed, although the contacts in the outer slot have no dangerous grid voltage.

Furthermore, it can be seen that in other instances it is also desirable to have a similar connection system with a larger, and therefore less curved, annular groove.

The disadvantage of larger diameter slots can be compensated for by a corresponding reduction in the width of the slot. However, this would make the two halves of the connector more difficult to fit together, increasing the likelihood that the annular connector of the device portion will be damaged by improper fit.

Disclosure of Invention

It is an object of the present invention to provide a device having improved resistance to the insertion of foreign objects. Viewed from a first aspect, there is provided a wireless electrical connector member comprising at least one annular groove for receiving an annular contact; and an electrical contact disposed in said slot, in use, to establish electrical connection with said annular contact; wherein the annular groove is locally narrower near the contact than the rest of the groove.

It can be seen by those skilled in the art that it is very difficult for an external object to be inserted into the slot to contact the electrical contacts therein by locally narrowing the slot in the vicinity of the contacts.

The narrowing of the groove may be performed at any point along the depth, and may even be performed over the entire depth of the groove. However, it is preferred that the narrowing is limited to the depth direction, preferably from the opening of the slot, which has the advantage of ensuring that the narrowing does not interfere with the most critical initial fit between the connector parts in use.

The narrow portion may take various forms. For example, a smooth decrease in width or a step-like change. The shape of the narrow portion may have the form of a continuous flange. However, the narrow portion of the slot preferably comprises a series of discrete projections, such as castellations. This has the advantage of allowing liquid to flow out of it, helping to prevent liquid from collecting in the connector. It is also possible in some embodiments to provide the projections with sufficient resilience that the moulding tool can be withdrawn through the projections to assist in the overall moulding process. However, in a preferred embodiment, the projections are formed on a parting line between the two halves of the molding tool.

As mentioned above, the present invention is particularly applicable to large diameter annular grooves, rather than the current neutral ring of P72. The invention is not limited to large diameter slots. The invention can also be used to increase the width of the small slot when the standard permits, while maintaining the same degree of resistance to the passage of foreign objects in the vicinity of the contacts.

The applicant has further recognised that when the connector has an increased diameter, the percentage of manufacturing tolerances will increase, possibly causing an increase in lateral play between the two connector parts, and so suggests means to at least partially address this problem. To this end, according to a preferred embodiment, the connector parts comprise means provided on the housing which allow a lateral proper positioning of the corresponding connector part when the two connectors are fully engaged.

It will thus be seen that according to this preferred embodiment, more free lateral engagement can be achieved before full engagement to assist in the engagement of the two components, but when the connectors are fully engaged the locating mechanism will correctly locate the two connector components relative to each other by preventing any unwanted large lateral movement. It is critical to ensure that the electrical contacts of the connector components are in good electrical contact with the annular conductor or joint, as compared to other conditions. This is particularly true where the contact rests on the end face of the conductor, as the contact area may be small.

In a preferred embodiment, the positioning mechanism is further adapted to align the annular conductor with a connector of the device before the annular conductor encounters the narrow portion of the annular groove. This is clearly very suitable for the preferred form of narrowing from the opening of the slot.

It is believed that this feature is novel and inventive within the scope of the invention, and thus, as will now be explained in a second aspect of the invention, the invention provides a first wireless connector part for engagement with a corresponding second wireless connector part, the first part comprising means on the housing for laterally locating the second connector part properly when the two connectors are fully engaged, and the locating means having an outer engagement surface substantially parallel to the connector axis.

Preferably, the first connector part is provided on a wireless base and the second connector part is provided on a wireless device. The type of connector part is preferably one that allows engagement regardless of relative angular position.

The detent mechanism may provide a degree of detent as soon as the two connector parts are engaged, but preferably only at the final stage of engagement. An example of a suitable locating mechanism is a flange that extends around the base of the connector (so that the flange can only make contact with the other connector component when the two components are fully engaged). However, it is preferred that a plurality of circumferentially spaced projections are provided, preferably four. This will save some material costs.

The positioning mechanism preferably has an outer engagement surface substantially parallel to the axis of the connector, i.e. in the direction in which the two connector parts approach for engagement. However, the outer engagement surface is preferably slightly tapered, e.g., 1-2 degrees, so that the thickness of the lowermost portion of the detent mechanism is selected to provide a tight fit between the connector components in the fully engaged position without impeding final engagement. Which may result in the user not being able to fully engage the components.

As mentioned above, this aspect of the invention is particularly applicable to large diameter wireless circular connectors, as well as to connectors of conventional size or even non-360 degrees, such as rectangular connectors.

Drawings

Preferred embodiments of the present invention will now be described by way of example and with reference to the accompanying drawings. Wherein,

fig. 1 is a plan view of a base of a 360 degree wireless electrical connector according to the present invention;

FIG. 2 is a bottom view of the connector portion shown in FIG. 1;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2;

FIG. 4 is a side view of the connector portion shown in FIGS. 1 to 3;

FIG. 5 is a cross-sectional view of the shaft through two diametrically opposed positioning members; and

fig. 6 is a view similar to fig. 3 showing the two connectors engaged.

Detailed Description

Turning now to fig. 1, fig. 1 shows a plan view of a base member of a 360 degree wireless electrical connector according to the present invention. Such connectors allow for the provision of power to wireless devices without regard to relative angular position. The basic principle of such a device is disclosed in WO 95/08204.

For further details reference is made to WO 95/08204. As with the connector system disclosed in WO 95/08204, the base connector part shown in fig. 1 is provided with a central bore 2 to accommodate a wire connection on a corresponding equipment connector part. Grounding lugs are also provided, although not visible in the drawings, which project from the circumference of the connector part to engage with the inner surface of the outermost grounding ring of the device connector in exactly the same manner as described in WO 95/08204.

Outside the central bore 2 is an annular groove 4 for receiving an annular conductor of a component of the device connector. Two concentric annular grooves 6, 8 are also provided for receiving two further annular conductors (see conductors 28, 30 in fig. 6) of the corresponding device connector part.

Leaf spring contacts (not shown) provided on the connector part are in use in electrical contact with the terminal points of the wire connector and the ring conductor respectively (see contacts 19, 20 in figures 3 and 6).

In the embodiment described, the outermost annular groove 8 is arranged to be connected to the neutral pole of an alternating current source. This means that the annular groove is spaced as far as possible from the line connection 2, which further improves the safety.

The two further poles 4, 6 of the connector may provide electrical connection of the electronic control circuitry of the base to a pair of thermal sensors located on a thick film heating element of the device.

The two further annular grooves 6, 8 are arranged outside the first annular groove 4 and therefore have a larger diameter and correspondingly a smaller curvature. In order to make it more difficult for an external object to be inserted into the two outer grooves 6, 8, in view of the smaller curvature, two series of circumferentially spaced restrictions 10, 12 are provided in the grooves 6, 8, respectively. This arrangement improves the outflow of spilled water through the connector.

The limiter 12 arranged in the outermost slot 8 is located substantially at the top of the slot, as seen in the orientation of fig. 1, while the limiter 10 located in the next slot 6 is located at the bottom of the slot. The reason for this is that the limiter is part of the respective slot 6, 8 in which the leaf spring contact is provided.

Although the leaf springs have been omitted from the bottom view of fig. 2, the fixing locations 14 of the contacts of the outermost slots and the fixing locations 16 of the contacts of the second outer slots 6 can be clearly seen. These fixing locations 14, 16 are located such that the leaf spring contacts are located below the respective limiters 10, 12 in the slots 6, 8 when mounted.

This arrangement is shown more clearly in the cross-sectional view of fig. 3. In the figure it can be clearly seen that the ends of the leaf spring contacts 18, 20 are located in the two outermost annular grooves 6, 8, respectively. In addition, the limiters 10, 12 are arranged in the contact regions in the annular grooves 6, 8. These additional protection against the insertion of foreign objects are therefore provided where it is most needed, preventing the foreign objects from touching the electrical contacts 18, 20.

As can be seen from fig. 3, even when it is intended to insert the annular conductors into the annular grooves 6, 8, when the ends of the conductors are close to the restrictions 10, 12, the conductors can be inserted through the restrictions 10, 12 only within a small angular range from the vertical.

To avoid the problem of the ends of the annular conductors of the device connector components sticking to the limiters 10, 12, a series of 4 circumferentially arranged positioning elements 22 are provided around the base of the upwardly projecting portion 24 of the connector component, as shown in the side and cross-sectional views of fig. 4 and 5, respectively. The securing member 22 is in the form of a protrusion extending in both horizontal and vertical directions from the base inclined surface of the upwardly projecting portion 24 of the connector component. As best seen in fig. 5, the outward surface 22a of the locating member 22 is actually offset from vertical toward the centerline of the connector component by an angle of about 1 to 2 degrees. It can also be seen that the horizontal angle of the positioning member 22 is rounded.

The device connector component includes an external ground skirt in which are three concentric annular conductors and a central connector. In use, the device connector component is approached towards the base connector component shown in the drawings. Contact is first made when the circumscribing grounding skirt contacts the circular upper edge 26 of the base connector component. The shape of the upper edge 26 allows the device connector roll to properly align with the base connector component. The annular conductors and the central contacts of the device connector then start to enter the corresponding holes 2 to 8 of the base part.

When the two connector parts are brought into close proximity to engagement, the outer ground skirt will engage the outwardly facing surfaces 26a of the four locating members 26 as shown in figure 6. The locating member substantially eliminates any lateral play between the two connector parts and ensures that the two outermost annular conductors 28, 30 can easily pass the limiters 10, 12 in the annular grooves 6, 8 and come into contact with the leaf spring contacts 18, 20. The slight deflection of the positioning member 26 allows the final engagement position to be tightened while avoiding binding during engagement.

In addition to the beneficial effect of guiding the annular conductor through the restriction in the annular groove, the four locating members 22 ensure that the two connector parts are tightly engaged when fully engaged. Despite the fact that relatively large diameters may cause large lateral play due to manufacturing tolerances.

Thus, it can be seen that the described embodiments provide a multi-pole 360 degree connector. Such a connector allows for easy initial engagement and a firmly defined final engagement. In addition, by appropriate curvature of the inner bores 2, 4, and the curvature of the restrictions 10, 12 in the outer slots 6, 8 in combination with the width, external objects such as tea spoon handles and the like are prevented from accessing the electrical contacts of the base connector.

Claims (6)

1. A first radio connector part for engagement with a corresponding second radio connector part, the first part comprising a mechanism on the housing which when the two connector parts are fully engaged, can laterally locate the second connector part appropriately, and

the positioning mechanism has an outer engagement surface substantially parallel to the connector axis.

2. The connector component of claim 1, wherein the first connector component is disposed on a wireless base and the second connector component is disposed on a wireless device.

3. Connector parts according to claim 1, characterized in that the connector part types are of a type that allows engagement independent of relative angular position.

4. A connector component according to any of claims 1 to 3, wherein the locating mechanism provides location only at the final stage of engagement.

5. A connector component according to any one of claims 1 to 3, wherein the locating means comprises a plurality of circumferentially spaced projections.

6. The connector components of claim 1, wherein the outer engagement surface is slightly tapered, and the thickness of the detent mechanism at the bottom most portion allows for tight positioning between the connector components in the fully engaged position without impeding final engagement.

Images