The invention relates to a connector stud, and an electronic device and a connector system which each comprise the connector stud.

Connector systems are known for detachably connecting electronic devices, such as radios and other mobile communications devices, and other equipment to a user’s clothing or another item.

Such connector systems typically comprise a male connector stud which is attached to or incorporated into the equipment. A separate female dock may be sited on the item to which the equipment is to be fastened and the connector stud engages with the dock to affix the equipment in the required position.

Such connector systems may be used by police officers and other such personnel, where the proper retention of the equipment is safety critical and thus the connector system must be sufficiently robust to avoid the equipment being inadvertently released from the connector dock.

The invention seeks to provide an improved connector stud which aids integration into equipment, particularly electronic devices.

In accordance with an aspect of the invention, there is provided a connector stud comprising: a base component comprising a base plate and a spacer which projects away from the base plate; a head component comprising a neck portion and a head portion, the head portion having a regular polygonal shape; wherein one of the spacer and the neck portion comprises a recess and the other of the spacer and the neck portion comprises a complementary protrusion which is received by the recess; wherein the recess and the protrusion are configured (i.e. shaped and/or positioned) to prevent rotation of the head component relative to the base component; wherein the base component comprises a threaded insert which sits at least partially within a thickness of the spacer for receiving a screw which passes through the neck portion of the head component to fasten the head component to the base component; wherein the base component and the head component are formed from dissimilar materials.

The head component may be formed from a self-lubricating material. The head component may be formed from Nylon 6.

The base component may be formed from ABS.

The recess may be non-circular.

The recess may have rotational symmetry. The recess may be cruciform-shaped.

The threaded insert and screw may be aligned with an axis of symmetry of the head portion. The head portion may comprise a slot which extends radially into the head portion to its axis of symmetry.

In accordance with another aspect of the invention, there is provided an electronic device comprising the connector stud described previously.

The base component may be integrally formed in a housing of the electronic device.

The electronic device may be a mobile communications device. In accordance with another aspect of the invention, there is provided a connector system comprising the connector stud described previously and a connector dock configured to engage with the connector stud.

The connector dock may comprise a receiving portion for receiving the head portion of the connector stud which comprises an indexing mechanism which preferentially biases the head portion into a plurality of discrete angular positions.

The indexing mechanism may be formed by a pair of biasing surfaces which lie parallel to opposing sides of the head portion and are spaced from one another by a distance which is greater than the width between opposing sides of the head portion, but which is less than the width between opposing corners of the head portion. The connector dock may comprise a cantilevered tab with a barb at its distal end which engages with the head portion. The barb may engage the head portion such that the connector stud can only be withdrawn from the connector dock when the slot is aligned with a withdrawal direction.

For a better understanding of the invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:-

Figure 1 is a perspective view of a connector stud according to an embodiment of the invention; Figure 2 is an exploded view of the connector stud of Figure 1 ;

Figure 3 is a plan view of the connector stud;

Figure 4 is a cross-sectional view of the portion A of the connector stud encircled in Figure 3;

Figure 5 is a bottom view of a head component of the connector stud;

Figure 6 is a perspective view of a connector dock for use with the connector stud;

Figure 7 is a rear view of the connector dock; and

Figure 8 is a rear view of the connector dock with the connector stud engaged therein. Figure 1 shows a connector stud 2 according to an embodiment of the invention. As shown in Figure 2, the connector stud 2 is generally formed from a base component 4 and a head component 6 which are formed as discrete, separate elements which are detachably connected to one another via a screw 8. The base component 4 comprises a base plate 10 and a spacer 12 which is a circular protrusion (although other shapes may be used) which projects upwards (i.e. away) from the base plate 10.

A non-circular recess 14 is formed at the centre of the spacer 12. In this example, the recess 14 has a cruciform profile formed by four lobes, as best seen in Figure 3. A threaded insert 16 is located at the centre of the recess 14 within the body of the base plate 10. As shown in Figure 4, the threaded insert 16 sits at least partially within the thickness of the spacer 12.

The head component 6 comprises a head portion 18 and a neck portion 20 (see Figure 5) extending from the head portion 18. The head portion 18 has a regular polygonal shape such that it has rotational symmetry. In this example, the head portion 18 has eight sides and so is octagon-shaped; however, it will be appreciated that other regular polygon shapes may be used with fewer or greater sides.

A slot 22 extends radially into the head portion 18 along one of the sides of the polygonal shape. The slot 22 extends to the centre (its axis of symmetry) of the head portion 18.

A protrusion 24 extends from (or is formed by) the neck portion 20. The protrusion 24 is complementary to the recess 14. In this example, the protrusion 24 is formed by four separate protruding portions which are configured (i.e. are sized and positioned) to engage with the four lobes of the recess 14; although in other examples the protruding portions may be contiguous.

The protrusion 24 of the head component 6 is engaged in the recess 14 of the base component 4 to prevent relative rotation between the head component 6 and the base component 4. The screw 8 is then passed through a hole 26 formed through the centre of the head portion 18 and neck portion 20 and engages with the threaded insert 16 to maintain the engagement between the protrusion 24 and the recess 14. The hole 26 is counterbored (or countersunk) such that the head of the screw 8 sits below the level of the slot 22. To aid assembly of the base component 4 and the head component 6, it is desirable that the protrusion 24 positively engages with the recess 14 so as to prevent axial movement of the protrusion 24 out of the recess 14 under a relatively small axial force. In particular, the protrusion 24 may clip into the recess 14 via a formation, such as a rib or ridge, or via an interference fit. This holds the head component 6 in place while the screw 8 is screwed into the base component 4.

Figures 6 shows a connector dock 28 for use with the connector stud 2 described previously. As shown, the connector dock 28 comprises a base plate 30 and a receiving portion 32 which projects upwards (i.e. away) from the base plate 30. The receiving portion 32 comprises a pair of side walls 34a, 34b projecting upwards (i.e. away) from the base plate 30 and a retaining wall 36 extending between the side walls 34a, 34b such that the retaining wall 36 runs parallel to, but is spaced from, the base plate 30. A keyhole slot 38 is formed in the retaining wall 36. The keyhole slot 38 extends into the retaining wall 36 between the side walls 34a, 34b. The keyhole slot 38 has a wider opening and then tapers to a narrower throat portion.

The base plate 30 comprises a cantilevered tab 40. A retaining barb 42 projects upwards (i.e. away) from the tab 40 towards the plane of the retaining wall 36. The tab 40 lies parallel to the keyhole slot 38 with the barb 42 provided at a distal end of the tab 40 such that it is aligned with the narrower throat portion of the keyhole slot 38. The barb 42 is inclined with respect to the plane of the base plate 30 such that it rises towards the distal end of the tab 40.

The base plate 30 and the receiving portion 32 together define a T-slot for receiving the connector stud 2. Specifically, the connector stud 2 is slid into the connector dock 28 such that the head portion 18 of the connector stud 2 is received between the base plate 30 and the retaining wall 36, with the neck portion 20 received by the keyhole slot 38 and the barb 42 positioned at the centre of the head portion 18 (in alignment with the screw 8 and the hole 26) within the slot 22. The head portion 18 can be inserted into the T-slot in any orientation since the barb 42 is able to ride up and over the periphery of the head portion 18, thereby deflecting the cantilevered tab 40, before engaging in the slot 22.

As shown in Figure 7, the side walls 34a, 34b of the receiving portion 32 define a pair of biasing surfaces 44a, 44b which face one another. As shown in Figure 8, the head portion 18 is received between the biasing surfaces 44a, 44b. The biasing surfaces 44a, 44b run parallel to one another and are spaced apart by a distance which corresponds to the width wi (as shown in Figure 5) between opposing sides of the head portion 18. Specifically, the spacing between the biasing surfaces 44a, 44b is greater than the width wi between opposing sides of the head portion 18, but less than the width w ₂ between opposing corners (vertices) of the head portion 18 (i.e. the diameter of the circumcircle encircling the head portion 18). Accordingly, rotation of the head portion 18 about its axis of symmetry (which is coincident with the position of the barb 42) is only possible by the deflection (i.e. deformation) of the biasing surfaces 44a, 44b or deformation of the head portion 18 itself. Such deformation must result in the spacing between the biasing surfaces 44a, 44b being greater than the diameter of the head portion 18 in order to allow rotation. It will be appreciated that after clearing opposing corners of the head portion 18, the biasing surfaces 18 are allowed to return to their original rest position. The biasing surfaces 44a, 44b therefore form an indexing mechanism which preferentially biases the head portion 18 into a plurality of discrete angular positions in which opposing sides of the head portion 18 lie parallel with the biasing surfaces 44a, 44b. In this case, since the head portion 18 has eight sides, the connector stud 2 has seven preferred angular positions (at 45 degree intervals) with respect to the connector dock 28.

As described previously, the head portion 18 can be inserted into the T-slot in any orientation since the barb 42 is able to ride up and over the periphery of the head portion 18. However, once the barb 42 is engaged in the slot 22 of the head portion 18, the connector stud 2 cannot be removed from the connector dock 28 unless the slot 22 is aligned with an insertion/withdrawal direction (see the arrows in Figure 8), with the open end of the slot 22 positioned so as to allow the barb 42 to be removed. The connector stud 2 can therefore only be removed from the connector dock 28 in one of the angular positions, thereby preventing inadvertent detachment.

As described previously, the connector stud 2 utilises a two-piece construction comprising the base component 4 and the separate head component 6. This allows the head component 6 to be replaced if it breaks or becomes worn. Further, this allows the base component 4 and the head component 6 to be formed from dissimilar materials.

In particular, the head component 6 is formed from a self-lubricating material, such as Nylon 6. This allows the head component 6 of the connector stud 2 to rotate within the indexing mechanism formed by the connector dock 28, while minimising wear. The base component 4 may be connected to or integrally formed as part of the housing of an electronic device, such as a mobile communications device (e.g. a police radio). The base component 4 may therefore be formed from an impact resistant material, such as Acrylonitrile Butadiene Styrene (ABS).

As described previously, the non-circular recess 14 and corresponding protrusion 24 form an anti-rotation feature. Although non-circular, it is desirable for the recess 14 and protrusion 24 to have rotational symmetry in order to allow re-orientation of the head component 6 relative to the base component. In particular, in the example shown, where a cruciform recess 14 is used, the head component 6 can be reoriented through 90 degree intervals. This allows the axis of the insertion/withdrawal direction relative to the device to be altered, if desired.

As described previously, the threaded insert 16 is received within the spacer 12 which also defines the recess 14 of the anti-rotation feature. Accordingly, the thickness of the connector stud 2 is minimised. The screw 8 which runs through the centre of the neck portion 20 also provides reinforcement to the neck portion 20.

In the example described above, the biasing surfaces 44a, 44b run parallel to one another to correspond to the opposing sides of the head portion 18. In other examples, the head portion 18 may have an odd number of sides such that opposing sides are not parallel. In this case, the biasing surfaces 44a, 44b may be angled relative to one another to correspond with the sides of the head portion 18.

Although it has been described that the head component 6 has the protrusion 24 and the base component 4 has the recess 14, it will be appreciated that this arrangement may be reversed. Further, each of the head component 6 and the base component 4 may be provided with a combination of recesses and protrusions. Although, the recess 14 has been described previously as being non-circular, it will be appreciated that the anti-rotation feature could be formed by a plurality of circular recesses which together form a non-circular recess. In particular, the cruciform recess 14 shown could be replaced by four circular recesses which receive the four separate protruding portions of the neck portion 20.

To avoid unnecessary duplication of effort and repetition of text in the specification, certain features are described in relation to only one or several aspects or embodiments of the invention. However, it is to be understood that, where it is technically possible, features described in relation to any aspect or embodiment of the invention may also be used with any other aspect or embodiment of the invention.

The invention is not limited to the embodiments described herein, and may be modified or adapted without departing from the scope of the present invention.