Patent Description:
Electronic connectors for electronic devices, such as an electric hair trimming appliance, typically require waterproof mountings in the electronic device. For some electronic connectors, such as USB-C type connectors, the seals provided are usually small and less reliable than is desirable. <CIT> discloses a waterproof USB charging interface assembly for an electric shaver. Wherein the USB charging interface and the conductive column are installed on the PCB, and the plastic seat is integrally fixed to the periphery of the USB charging interface, the periphery of the PCB and the periphery of the conductive column in a sleeving mode. A port of the USB charging interface is exposed out of the lower end face of the plastic seat, and the plastic seat is inserted and fixed into an installation groove formed in the lower end of the electric shaver and makes close contact with the installation groove. The sealing cover is fixed at the opening of the lower end of the mounting groove and covers the lower end of the plastic seat, and the port of the USB charging interface is in butt joint with the window of the sealing cover.

<CIT> discloses an electronic connection module according to the preamble of claim <NUM>.

According to a first specific aspect, there is provided a n electronic connection module for mounting within an electronic device, the electronic connection module comprising: a connection port comprising a connector and a first sealing ring disposed on an outer surface of the connector at an open end of the connector, the open end being configured to receive a mating connector; an intermediate housing configured to receive the connection port, the intermediate housing comprising an inner surface against which the first sealing ring of the connection port interfaces to provide a seal between the inner surface of the intermediate housing and the connection port; a module housing configured to receive the intermediate housing and the connection port; a biasing unit disposed between the module housing and the connection port, the biasing unit configured to bias the connection port towards a shelf of the intermediate housing such that the open end of the connection port abuts the shelf of the intermediate housing to secure the connection port within the intermediate housing; and an O-ring disposed on an outer surface of the intermediate housing for interfacing with an inner surface of the electronic device, the O-ring being disposed between a ledge projecting from an outer surface of the intermediate housing and the module housing.

The intermediate housing may comprise a recess in the inner surface for receiving the first sealing ring.

The biasing unit may be integral with the module housing. The biasing unit may be in the form of a pre-tensioned leaf-spring. The biasing unit may be composed of polycarbonate or steel. The biasing unit may have a stiffness such that it resists deformation for a force being applied which is required to insert a mating connector in the connection port.

The module housing may be composed of polycarbonate or steel.

The shelf on the inner surface of the intermediate housing and the ledge on the outer surface of the intermediate housing may be opposing such that the O-ring is disposed on the outer surface of the intermediate housing directly opposing the first sealing ring of the connection port on the inner surface of the intermediate housing. The module housing may be configured to snap fit together with the intermediate housing.

The connection port may be a USB-C port. The connector may be a USB-C connector.

According to a second aspect, there is provided an electric hair trimming appliance comprising the electronic connection module according to the first aspect.

According to a third aspect, there is provided a kit of parts for an electronic connection module according to the first aspect, the kit of parts comprising: the connection port including the connector and the first sealing ring, the intermediate housing, the module housing, the biasing unit, and the O-ring.

According to a fourth aspect, there is provided a method of assembling an electronic connection module according to the first aspect, the method comprising: inserting the connection port through an open end of the intermediate housing until the open end of the connection port abuts the shelf of the intermediate housing opposing the open end of the housing; adding the O-ring to the outer surface of the intermediate housing against the ledge of the intermediate housing; inserting the intermediate housing with the connection port and O-ring into the module housing until the O-ring is secured between the module housing and the ledge of the intermediate housing, and such that the biasing unit is disposed between the module housing and the connection port, and such that the biasing unit biases the connection port against the shelf of the intermediate housing; and securing the module housing to the intermediate housing.

Securing the module housing to the intermediate housing may comprise connecting the module housing with a snap fit connection to the intermediate housing.

The connection port may be inserted though the open end of the intermediate housing until the first sealing ring is received in the recess of the intermediate housing.

<FIG> shows an electric hair trimming appliance <NUM> comprising a handle <NUM> and a trimming unit <NUM>. The handle <NUM> comprises an electric motor (not shown) which is connected to the trimming unit <NUM>, so as to reciprocate a blade for cutting hair. The electric motor is powered by a battery in this example, which requires charging.

The electric hair trimming appliance <NUM> comprises an electronic connection module <NUM> which is disposed in the handle <NUM> and which comprises a USB-C type connector (best shown in <FIG>) for connecting to a mating charger to charge the battery. In other examples, the connector may be any type of electronic connector, and may be to power the motor directly, rather than to charge a battery, or may be for data transfer.

<FIG> and <FIG> respectively show an isometric view and an exploded view of the electronic connection module <NUM>, and <FIG> shows a cross-sectional view of the electronic connection module <NUM> disposed within a cavity <NUM> of the electric hair trimming appliance <NUM>, defined by internal walls <NUM> of the electric hair trimming appliance <NUM>.

The electronic connection module <NUM> comprises a USB-C connection port <NUM> comprising a USB-C connector <NUM> (best shown in <FIG>) and a first sealing ring <NUM>. It may be, for example, an off-the-shelf waterproof USB-C connection port. The connector <NUM> comprises an open end <NUM> which is configured to receive a mating connector, and the first sealing ring <NUM> is disposed on an outer surface of the connector <NUM>. In other examples, the connector may be any type of connector, such as a USB-A connector, which is configured to mate with a corresponding connector.

In this example, the connection port <NUM> further comprises a PCB board <NUM> which is connected to the outer surface of the connector <NUM> and extends away from the open end <NUM> of the connector <NUM> and beyond an opposing end of the connector <NUM>.

The electronic connection module <NUM> further comprises an intermediate housing <NUM> which is configured to receive the connection port <NUM>. The intermediate housing <NUM> comprises an open end <NUM> through which the open end <NUM> of the connection port <NUM> is inserted, and a shelf end <NUM> opposing the open end <NUM>. The shelf end <NUM> is also open, to provide access from outside the intermediate housing <NUM> to the connector <NUM> for the mating connector.

Walls of the intermediate housing <NUM> extend between the shelf end <NUM> and the open end <NUM>, forming an intermediate cavity in which the connection port <NUM> is disposed, and defining an inner surface <NUM> against which the first sealing ring <NUM> of the connection port <NUM> interfaces to provide a continuous seal between the intermediate housing <NUM> and the connection port <NUM>.

In this example, a recess <NUM> in the inner surface <NUM> extends around the intermediate housing <NUM> to receive the first sealing ring <NUM>. Having the first sealing ring <NUM>, which is typically very small on an off-the-shelf connection port, guided along the inner surface <NUM> to be received within the recess <NUM>, ensures that the first sealing ring <NUM> is surrounded on more sides of its cross-section, which helps to prevent warping of the first sealing ring <NUM>, and thereby provides a more reliable seal. In other words, first sealing ring <NUM> provides radial sealing between the intermediate housing <NUM> and the connector <NUM>, and the recess <NUM> also provides an axial stop for the first sealing ring <NUM> against the surface of the recess <NUM> which wraps around the first sealing ring in an axial direction such that it prevents warping of the first sealing ring <NUM>, thereby improving the sealing performance of the first sealing ring <NUM>. In other examples, there is no recess in the inner surface, and the first sealing ring merely interfaces with the inner surface, thereby providing radial sealing.

The intermediate housing <NUM> further comprises a shelf <NUM> protruding into the cavity of the intermediate housing <NUM> at the shelf end <NUM>. The open end <NUM> of the connection port <NUM> is configured to abut the shelf <NUM> to prevent further insertion of the connection port <NUM> into the intermediate housing <NUM>, whilst enabling access to the connector <NUM> for a mating connector. In other words, the shelf <NUM> acts as the axial end stop for the connector <NUM>.

The intermediate housing <NUM> also comprises a ledge <NUM> extending from an outer surface of the intermediate housing <NUM> around the extent of the intermediate housing <NUM> on which an O-ring <NUM> is configured to sit on the outer side of the intermediate housing <NUM>.

The O-ring <NUM> is configured to interface with an inner surface of the walls <NUM> of the electronic hair trimming appliance (as shown in <FIG>) to provide a seal between the intermediate housing <NUM> and the walls <NUM> of the electric hair trimming appliance <NUM>. The O-ring can be of any suitable size to provide the required sealing performance.

The electronic connection module <NUM> further comprises a module housing <NUM> which is configured to receive the intermediate housing <NUM> and the connection port <NUM> through an open end <NUM> of the module housing <NUM>. The open end <NUM> of the module housing <NUM> comprises a profile matching a profile of the ledge <NUM> on the intermediate housing <NUM>, so that the O-ring <NUM> on the outer surface of the intermediate housing <NUM> is sandwiched between the ledge <NUM> and the module housing <NUM>.

In this example, the shelf <NUM> and the ledge <NUM> on the intermediate housing <NUM> are positioned to oppose one another, such that the O-ring <NUM> is positioned directly opposing the first sealing ring <NUM> when the connection port <NUM> abuts the shelf <NUM>. Having the first sealing ring <NUM> directly opposing the O-ring <NUM> means that the radial forces acting on the intermediate housing <NUM> from the first sealing ring <NUM> and the O-ring <NUM> are directly opposing, such that there is no or minimal moment applied to the intermediate housing <NUM>, thereby reducing the stiffness required for the wall of the intermediate housing <NUM>.

The intermediate housing <NUM> and the module housing <NUM> are secured together with a snap fit connection. Specifically, the intermediate housing <NUM> comprises apertures <NUM> in the walls of the intermediate housing <NUM> which cooperate with tabs <NUM> on the module housing <NUM>. It will be appreciated that in other examples, the module housing may comprise the apertures, and the intermediate housing may comprise the cooperating tabs of the snap fit connection.

The snap fit connection is configured to secure the O-ring <NUM> between the ledge <NUM> and the module housing <NUM>, so as to provide a reliable seal between the intermediate housing <NUM> and the module housing <NUM>. The ledge <NUM> and the module housing <NUM> thereby provide axial stops for the O-ring <NUM> to prevent axial movement of the O-ring <NUM>. This snap fit connection improves ease and speed of assembly as no screws or other external securing components, or steps, are required.

The electronic connection module <NUM> further comprises a biasing unit <NUM> which, in this example, is integral with the module housing <NUM>. The biasing unit <NUM> is disposed between the module housing <NUM> and the connection port <NUM>, and is configured to bias the connection port <NUM> towards the shelf <NUM> of the intermediate housing <NUM>, such that the open end <NUM> of the connection port <NUM> abuts the shelf <NUM>. This secures the connection port <NUM> within the intermediate housing <NUM>, and within the module housing <NUM> since the shelf <NUM> provides the end stop to prevent further insertion of the connection port <NUM> into the intermediate housing <NUM>, and the biasing unit <NUM> prevents the connection port <NUM> from coming out of the intermediate housing <NUM> thereby squeezing the connection port <NUM> between the module housing <NUM> and the shelf <NUM>. In other examples, the biasing unit may be separate from the module housing <NUM>.

In this example, the biasing unit <NUM> has a stiffness such that it resists deformation for a force being applied which is required to insert a mating connector in the connection port <NUM>. Biasing the connection port <NUM> against the intermediate housing <NUM> with a biasing unit <NUM> having this stiffness ensures that the connection port <NUM> remains in contact with the intermediate housing <NUM>, even during plugging and unplugging of a mating connector, such that the first sealing ring <NUM> remains disposed within the recess. This improves sealing performance of the first sealing ring <NUM>. If the biasing unit <NUM> has a stiffness lower that this, so that it deforms slightly upon insertion of a mating connector into the connection port <NUM>, the first sealing ring <NUM> may move out of the recess <NUM>, but it will still seal against the inner surface <NUM> of the intermediate housing <NUM>.

Further, having the O-ring <NUM>, which can be of any suitable size significantly larger than the first sealing ring <NUM>, disposed between the intermediate housing <NUM> and walls <NUM> of an electronic hair trimming appliance also improves the sealing performance of the electronic connection module <NUM> as a whole. Therefore, the configuration of the electronic connection module <NUM> improves sealing performance, particularly, for examples which use off-the-shelf USB-C connection ports having small first sealing rings.

The biasing unit <NUM> in this example is in the form of a pretensioned leaf spring. Having the biasing unit <NUM> disposed between the connection port <NUM> and the module housing <NUM> means that the dimensional tolerances are increased, since the connection port <NUM> will always be squeezed between the shelf <NUM> and the module housing <NUM>, thereby ensuring that the manufactured dimensions of the parts do not have to be as accurate.

Further, the O-ring <NUM> is received in a space between the module housing <NUM> and the intermediate housing <NUM>, and this space must be large enough to accommodate the O-ring <NUM> which is sealed against the wall <NUM> of the electric hair trimming appliance <NUM>, and deformed axially according to the Poisson effect. The module housing <NUM> should not impede the deformation of the O-ring <NUM> according to the Poisson effect, such that there is a minimum distance between the module housing <NUM> and the intermediate housing <NUM> when they are snap fit together, determined by the size of the O-ring <NUM>, but there is a large tolerance on the maximum distance between the module housing <NUM> and the intermediate housing <NUM>.

The biasing unit <NUM> in this example is composed of polycarbonate. Polycarbonate exhibits very low creep over time, which makes it a good material for the biasing unit <NUM>, which must be able to produce a large force to overcome plugging and unplugging actions of the mating connector to the connector <NUM> of the connection port <NUM>. It also has the benefit of being lightweight and easy to mould. Typically, polycarbonate cannot be used in equipment suitable for use in wet environments, since exposure to chemicals significantly degrades the polycarbonate. However, the superior sealing of the electronic connection module <NUM> means that this material can be used safely.

Since the biasing unit <NUM> in this example is unitary with the module housing <NUM>, and the module housing <NUM> is also protected from external conditions by the improved sealing of the electronic connection module <NUM>, the module housing <NUM> is also made of polycarbonate. In some examples, the biasing unit may be separate from the module housing and/or the module housing may be composed of a different material.

In other examples, the biasing unit and/or the module housing may be composed of steel, which also exhibits very low creep over time, or any other suitable material.

Although the electronic connection module <NUM> is described as being inserted in a cavity <NUM> of an electric hair trimming appliance <NUM>, it will be appreciated that the electronic connection module <NUM> may be inserted into a cavity in any suitable electronic device, where the O-ring is configured to interface with the walls of the electronic device defining the cavity to seal the cavity.

<FIG> is a flow chart showing steps of a method <NUM> of assembling the electronic connection module <NUM>.

In block <NUM>, the method <NUM> comprises inserting the connection port <NUM> through an open end <NUM> of the intermediate housing <NUM> until the open end <NUM> of the connection port <NUM> abuts the shelf <NUM> of the intermediate housing <NUM>, and until the first sealing ring <NUM> is received within the recess <NUM> of the intermediate housing <NUM>. It will be appreciated that, in examples where there is no recess in the inner surface of the intermediate housing, the first sealing ring will not be received in the recess.

In block <NUM>, the method <NUM> comprises adding the O-ring <NUM> to the outer surface of the intermediate housing <NUM> against the ledge <NUM> of the intermediate housing <NUM>. It will be appreciated that block <NUM> can be carried out before block <NUM>.

In block <NUM>, the method <NUM> comprises inserting the intermediate housing <NUM> with the connection port <NUM> and O-ring <NUM> into the module housing <NUM> until the biasing unit <NUM> biases the connection port <NUM> against the shelf <NUM>.

In other examples, where there biasing unit is separate from the module housing, the method may comprise inserting the biasing unit into the module housing before inserting the intermediate housing with the connection port and the O-ring into the module housing, to ensure that the biasing port is disposed between the module housing and the connection port.

In block <NUM>, the method <NUM> comprises securing the module housing <NUM> to the intermediate housing <NUM> with the snap fit connection by inserting the intermediate housing <NUM> with the connection port <NUM> and the O-ring <NUM> into the module housing <NUM> until the tabs <NUM> of the module housing <NUM> snap into the apertures <NUM> of the intermediate housing <NUM>. In other examples, it may include securing the module housing to the intermediate housing with screws, adhesive, or any other suitable means.

Claim 1:
An electronic connection module (<NUM>) for mounting within an electronic device (<NUM>), the electronic connection module (<NUM>) comprising:
a connection port (<NUM>) comprising a connector (<NUM>) and a first sealing ring (<NUM>) disposed on an outer surface of the connector (<NUM>) at an open end (<NUM>, <NUM>, <NUM>) of the connector (<NUM>), the open end (<NUM>, <NUM>, <NUM>) being configured to receive a mating connector (<NUM>);
an intermediate housing (<NUM>) configured to receive the connection port (<NUM>), the intermediate housing (<NUM>) comprising an inner surface (<NUM>) against which the first sealing ring (<NUM>) of the connection port (<NUM>) interfaces to provide a seal between the inner surface (<NUM>) of the intermediate housing (<NUM>) and the connection port (<NUM>);
a module housing (<NUM>) configured to receive the intermediate housing (<NUM>) and the connection port (<NUM>); and
an O-ring (<NUM>) disposed on an outer surface of the intermediate housing (<NUM>) for interfacing with an inner surface (<NUM>) of the electronic device, the O-ring (<NUM>) being disposed between a ledge (<NUM>) projecting from an outer surface of the intermediate housing (<NUM>) and the module housing (<NUM>);
characterized in that the electronic connection module (<NUM>) further comprises:
a biasing unit (<NUM>) disposed between the module housing (<NUM>) and the connection port (<NUM>), the biasing unit (<NUM>) configured to bias the connection port (<NUM>) towards a shelf (<NUM>) of the intermediate housing (<NUM>) such that the open end (<NUM>, <NUM>, <NUM>) of the connection port (<NUM>) abuts the shelf (<NUM>) of the intermediate housing (<NUM>) to secure the connection port (<NUM>) within the intermediate housing (<NUM>).