AU2003212046B2 - Electrical socket fitting with improved hinged cover or flap - Google Patents

Description

Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: Gerard Industries Pty Ltd Actual Inventor: Quentin David Cook Address for Service: MADDERNS, 1st Floor, 64 Hindmarsh Square, Adelaide, South Australia, Australia Invention title: ELECTRICAL SOCKET FITTING WITH IMPROVED HINGED COVER OR FLAP Details of Associated Provisional Application No. 2002950160 dated 12t July 2002 The following statement is a full description of this invention, including the best method of performing it known to us.

(PatAU131) This invention relates to an electrical socket fitting having an improved hinged cover or flap which is designed so that when the plug is removed from the socket, the cover or flap will automatically dose to thereby sealingly close off the access opening in the housing of the socket. More particularly, the present invention is concerned with cord extension sockets and electrical appliance inlets, single or poly phase; however, the invention is not necessarily restricted to such products as it has application for use in IP and non IP rated socket outlets and many products that require water protection.

Many types of weather and/or dust proof electrical fittings which comprise an electrical industrial plug and socket are well known in the industry and the applicant is aware of several IP rated products which have been available in the marketplace for some years. Many methods to gain an IP rating of IP 56 or IP 66 have been attempted over the years. The most accepted known to the applicant in Australia is a fitting which makes use of a bias hinged flap which can swing between opened and closed positions and which when closed co-operates with a separate spring loaded latch. The latch is required to automatically lock the flap closed against a seal face, when the fitting is not in use. Other designs known to the applicant do not have a latch but are subject to lower IP ratings as the pressure from a water blast can open a non latched flap and allow water to enter the socket interior. Other designs require the user to lock the flap when closed, manually.

An example of an IP rated fitting is described and illustrated in US Patent 4500008 (PDL Industries) dated 19 February 1985. This particular fitting requires the user to squeeze the latch against a fixed face of the flap so as to release same, manually rotating the hinge flap to its fully open position, and then subsequently inserting the plug of the appliance inlet into the socket housing of the fitting. There are however, a number of a practical disadvantages associated with a fitting of this kind. These are discussed hereunder.

Firstly, the finger operated latch is difficult to release due to the small amount of latch face which is available and as well is heavily protected by walls and rims to prevent it from damage if dropped on hard surfaces. This problem is further increased when the user is wearing gloves as is common practice for industrial users.

Secondly, the design of the fitting is such that the latch is exposed and is prone to damage. The latch is made up of two parts, a latch member and a plastic spring. The latch face works by rotating about a fulcrum and finger pressure being applied against the spring. The latch face is outside of the flap and latchingly engages with a ledge on the housing of the fitting. When the flap is open to its full extent, the plug is inserted and the flap is released. The rotational speed of the flap has a resultant impact on the latch and in practice, such impact has been known to cause the latch to fracture. The latch can also get caught in the plugs locking ring when trying to separate the plug from the latch housing, which again may result in the latch being broken or damage being done to the locking ring.

In practice, when the cord extension socket is fitted to a plug, the two joined components are usually dropped to the ground. This impact can result in a side force being applied to the flap. As the latch is like a tooth, the flap tends to twist more because the latch falls off the round diameter of the plug causing massive stresses on the flap pivot and in many cases results in the flap being broken at or near its pivot point.

Still further the pivot arrangement used for the flap may also be broken when the plug is being inserted into the socket housing. The flap has a single pivot point with a spring loaded return centred on the pivot axis. The spring returns the flap to the closed position after being opened. The fixed pivot point is subject to breaking, especially when inserted into a plug, due to its rigidity and the fact that the flap offers a significant mechanical advantage over the pivot.

Still another problem is the difficulty to hold the flap open to either insert or withdraw the plug, especially when using cord extension sockets having a high current rating, due to the fact that no provision is readily available for the user to hold the flap open.

It is the main object of the present invention therefore, to provide an improved electrical socket fitting which incorporates a hinged pivotal flap which is constructed in a manner which allows a user to open and dclose the flap simply and quickly, and which automatically latches itself in the closed position.

It is another object of the present invention to provide an improved electrical socket fitting having a hinged and latchable cover or flap which utilises a minimal number of components while still being reliable through numerous opening/closing cycles.

It is yet another object of the present invention to provide an improved electrical socket fitting having a hinged and latchable cover/flap which is less likely to suffer damage in the event that the fitting is subjected to impact forces, eg by being dropped to the ground.

It is still a further object of the present invention to provide an improved electrical socket fitting having a hinged and latchable cover/flap which can be held in its open position in an extremely simple and convenient manner to allow the connecting plug to be either inserted or withdrawn.

Broadly according to this invention therefore, an improved electrical socket fitting of the kind having a socket housing which is open at one end and has a bore formed therein for receiving a socket which is adapted for connection to an electrical plug, a hinged flap/cover pivotally attached to said housing adjacent said open end thereof for movement between an open position wherein the flap lies dclear of the socket housing open end and permits the plug to be inserted into the socket and a dclosed position wherein the flap closes off said open end, and latching means for releasably locking said flap in its closed position, charadcterised in that; the hinged flap is supported by a pivot which is mounted for radial movement relative to the axis of the socket housing between a radially outer position wherein the flap is in a latched condition and a radially inner position wherein the latching means is released; and bias means biasing said pivot towards its radially outer position.

Desirably the latching means comprises a first latch portion integrally formed with a distal end portion of the cover/flap, and a second latch portion integrally formed on the exterior wall of the socket housing near said open end, said first and second latch portions, when the pivot is in its normal radially outer position, lockingly engaging one another in order to retain the flap in its said closed position.

Desirably the bias means is a torsion spring co-axially mounted with respect to the pivot, said pivot being a hinge pin which has each of its ends captively retained in a slotted opening formed in a radially projecting lug integrally formed with the socket housing. The spring is also arranged to bias the flap to its dosed position, whereby the flap, once released by the user, will latch in its closed position automatically. Of course, two separate springs may be used in order to spring-load the pivot pin and to bias the flap towards its closed position so that it will close automatically, once released.

Desirably said flap/cover is provided with a finger or thumb engaging flange formation which projects outwardly away from the outer surface of the flap on the hinged side thereof, and which allows the user to hold the flap open by applying finger or thumb pressure thereagainst, while holding the fitting in his or her hand.

Desirably, a seal is located between the inner surface of the flap and the open end of the socket housing to prevent the ingress of dust/moisture into the interior of the socket housing when the flap is in its dosed position.

The electrical socket fitting of this invention is particularly suited to cord extension sockets which connect to appliance inlet plugs for industrial use.

In order to more fully describe the applicant's invention, a preferred embodiment thereof is described hereunder in some further detail with reference to and as illustrated in the accompanying drawings wherein; Figure 1 is a schematic sectional view of the socket housing showing the hinged flap in its closed position; Figure 2 is a view similar to Figure 1, showing the flap in its delatched or released position and ready to rotate to its open position; Figure 3 is a top exploded perspective view of the socket housing shown in Figure 1; Figure 4 is a schematic elevational view of the socket housing shown in Figure 1 with the flap in its fully open position ready for insertion of the electrical plug; while Figure 5 is a perspective view of the components shown in Figure 4 connected together with the flap overlying the inserted plug.

Referring to Figures 1 to 4 of the drawings, there is shown an electrical socket fitting which comprises a moulded plastics housing 11 which has an open circular end 12, with its other end being closed off by means of a threaded plug 13 through which passes an electrical cord 14 which is electrically connected to a socket outlet (not shown) positioned in the bore 15 within the housing 11. The open end 12 is closed off by means of a hinged flap 17 which can be rotated between a fully open position (shown in Figure 4) and a latched closed position (shown in Figure 1) where the flap closes off the open end 12 of the housing 11.

The plastics or metal flap 17 is pivotally attached to the housing 11 by means of an integral pivot member 20 which has its ends retained within a pair of slotted openings 21 formed in spaced apart lugs 22, 22' (refer Figure 3) each of which projects radially outwards from the housing 11 adjacent the end 12. The pivot 20 is thus able to move radially with respect to the axis of the socket housing 11. The pivot 20 is spring loaded by means of torsion spring 23 which has a coil portion which encircles the pivot 20 and has a projecting leg 24 at one of its ends, which makes pressure contact with the outer surface of the housing 11 and functions to bias the pivot 20 radially outwards. The other end of the spring 23 terminates in an oppositely directed projecting leg 23' which is held captive in a recess 25 formed in side wall 26 of the flap 17. In order to delatch the flap 17, pressure is applied to the hinged side of the flap 17 so as to displace the pivot radially inwards, against the bias of the spring leg 24 which undergoes deflection.

As shown in Figures 1 and 2, the non-hinged or distal end of the flap 17 has an inwardly projecting skirt 27 which terminates at its free end in a catch part 28 which, when the flap is dclosed, engages in a snap-fit manner a radially outstanding ledge 29 integrally formed with the wall of the housing 11 on the side opposite to the hinge point of the flap. The bias produced by the spring return leg 24 ensures that the catch parts 28, 29 remain engaged.

It will be appreciated that by having a spring loaded pivot which is able to move radially with respect to the housing, in the event of the fitting being dropped and impacting against the ground, the spring loaded pivot will effectively act as a shock absorber and thereby cushion the impact.

As shown in Figure 4 of the drawings, the flap 17 is formed on its outer surface, adjacent the hinged side thereof, with a thumb or finger engaging flange 31 which allows the user to conveniently hold the flap in its fully open position while holding the fitting in one hand only, thereby facilitating the insertion of the plug 32 into the socket within the housing 11 as well as its withdrawal therefrom (using one's other hand).

As also shown in Figures 1 and 2, an annular seal 33 is located on the inner face of the flap 17 and, when the flap is dclosed, sealing engages against the perimeter end surface of the housing 11.

Referring to Figure 5 of the drawings, in order to inhibit any relative transverse movement between the flap 17, when in its open position overlapping the plug 32, and the plug body 33, the leading end of the flap is provided with a protrusion 34 which lockingly locates in an indent or groove 35 formed in the outer surface of the plug body 33. With this arrangement, side forces are much less likely to cause any damage to the flap pivot mounting.

In order to open the flap 17 of the socket housing 11, the user is able to use the whole of his hand so as to push the flap 17 bodily downwards thereby causing its pivot 20 to move radially inwards against the bias of the spring leg 24 and in turn release the latch part 28 from the ledge 29 on the socket housing 11, whereupon the flap 17 can be rotated to an open position against the bias of spring 23. Once open, the user holds the flap 17 in the open position by applying thumb pressure against the flange 31 on the top face of the flap 17 and thereafter inserts the plug 32 into the socket housed within the housing 11.

In order to disconnect the plug 32 from the socket housing 11, the flap 17 is once again held in the position shown in Figure 3 and with the user's other hand, the plug 32 is axially withdrawn from the housing 11. Once the open flap 17 is released, it will automatically rotate to its closed position assisted by the torsion spring 23 and latch with the socket housing 11 (by means of a snap-fit action).

It should be appreciated that numerous modifications and variations may be made to the above described embodiment without departing from the spirit and scope of the present invention as those skilled in the art will readily understand.

A brief consideration of the above described embodiment will indicate that the invention provides for a very simple and effective hinged cover/flap arrangement for an electrical socket housing whereby the flap can automatically swing shut and latch itself in its dclosed position. The flap arrangement of this invention is also advantageous in that it is less prone to damage in the event of the fitting being subject to impact forces, and permits the flap to be very conveniently held in an open position when inserting or withdrawing the plug.

Claims (9)

1. An improved electrical socket fitting of the kind having a socket housing which is open at one end and has a bore formed therein for receiving a socket which is adapted for connection to an electrical plug, a hinged flap pivotally attached to said housing adjacent said open end thereof for movement between an open position wherein the flap lies clear of the socket housing open end so as to permit the plug to be inserted into the socket and a closed position wherein the flap dcloses off said open end, and catch means for releasably locking said flap in said dclosed position, the improvement wherein: said hinged flap is supported by a pivot which is mounted for radial movement relative to the axis of the socket housing between a normal radially outer position and a radially inner catch release position wherein the catch means is released and the flap can rotate to its said open position, and bias means biasing said pivot towards said radially outer position.

2. An electrical socket fitting according to claim 1 wherein said bias means is a torsion spring arranged to also bias said flap towards its closed position so that the flap, once released from its said open position, will rotate to its said closed position and the catch means engaged to automatically lock the flap in its said dosed position.

3. An electrical socket fitting according to either claim 1 or 2 wherein said catch means comprises a first catch portion integrally formed with a distal end portion of the flap, and a second catch portion integrally formed on the exterior wall of the socket housing near said open end, said first and second catch portions, when the pivot is in its normal radially outer position, latchingly engaging one another in order to secure the flap in its said closed position.

4. An electrical socket fitting according to either claim 2 or 3 wherein said torsion spring is co-axially mounted on the pivot, said pivot extending between and retained in aligned slotted openings formed in a pair of radially projecting spaced apart lugs integrally formed with the socket housing.

An electrical socket fitting according to claim 4 wherein said torsion spring terminates at one of its ends in a projecting leg which makes pressure contact with an outer surface portion of the housing, and at its other end in a projecting leg which is held captive in a recess formed in a side wall of said flap.

6. An electrical socket fitting according to any one of the preceding claims wherein said flap is provided with an outwardly projecting finger or thumb engaging flange formation on the hinged side thereof, said flange formation permitting the user to hold the flap in its said open position by applying finger or thumb pressure thereagainst, while holding the fitting in his or her hand.

7. An electrical socket fitting according to any one of the preceding claims further comprising an annular seal located between the inner surface of the flap and the open end of the socket housing to prevent ingress of dust or moisture into the interior of the socket housing when the flap is in its closed position.

8. An electrical socket fitting according to any one of the preceding dclaims wherein the non-hinged side of the flap is provided with an integral protrusion locatable in an indent or groove formed in the outer surface of the plug body, whereby with the flap in its said closed position, any relative transverse movement between the flap and the plug body is inhibited.

9. An electrical socket according to any one of the preceding claims wherein said flap is formed with an annular skirt, said skirt terminating (on the non-hinged side of the flap) in an inwardly projecting lip which forms said first catch portion, said second catch portion comprising a radially outwardly projecting ledge, said lip and said ledge snap-fittingly engaging one another when the flap is rotated to its closed position. An improved electrical socket fitting substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings. Dated this 11th day of July, 2003. Gerard Industries Pty Ltd By its Patent Attorneys MADDERNS