IP Verse

Charger Plug With Improved Package

Patent No. USRE48794 (titled "Charger Plug With Improved Package") was filed by Volstar Tech Inc on Dec 4, 2018.

What is this patent about?

’794 is related to the field of charger plugs, specifically those used for portable electronic devices. The background highlights the ongoing need to reduce the size and cost of these plugs. Existing designs often struggle with a trade-off between reduced vertical/lateral dimensions and increased length, leading to inconvenience and potential damage. Manufacturing costs are also a concern, particularly due to the use of insert molding for securing the blades and manual soldering for connecting them to internal circuitry.

The underlying idea behind ’794 is to simplify the construction of a charger plug by using slidably mounted blades and spring contacts to establish electrical connections. This eliminates the need for insert molding and soldering, reducing both size and manufacturing complexity. The design aims for a compact form factor that doesn't obstruct adjacent outlets while maintaining robust electrical connections.

The claims of ’794 focus on a charger plug designed for converting AC power to DC power for rechargeable electronic devices. The key elements include separate blade members secured within a housing, prong portions extending from the housing for insertion into a power source, and a DC connector with an aperture for receiving a power cord. The independent claim specifies size constraints (length ≤ 2.0 inches, width < 1.75 inches) and a non-interference requirement with adjacent power receptacles.

In practice, the invention uses a two-part housing that encloses the internal circuitry. The blades, instead of being molded into the housing, are slid into place and secured. Spring contacts, mounted on the internal circuit board, press against the blades to create a reliable, solderless electrical connection. This design allows for easier assembly and disassembly, and reduces the overall size of the plug.

This approach differs from prior art by avoiding insert molding and soldering. The use of spring contacts provides a cost-effective and space-saving alternative to traditional connection methods. The specific dimensions and the requirement of non-interference with adjacent outlets address the practical limitations of existing charger plugs, making it more convenient for users in space-constrained environments.

How does this patent fit in bigger picture?

Technical landscape at the time

In the late 2010s when ’794 was filed, at a time when portable electronic devices were ubiquitous, AC adapter plugs were commonly implemented using insert-molded blades and hand-soldered connections to internal circuitry. At this time, reducing the size and manufacturing cost of such plugs was a persistent engineering constraint.

Novelty and Inventive Step

The claims were amended during prosecution. The examiner issued a non-final rejection based on obviousness over prior art. Claims 8 and 10 were objected to. The prosecution record does NOT describe the technical reasoning or specific claim changes that led to allowance.

Claims

There are 22 claims in total, with claim 1 being the only independent claim. Independent claim 1 is directed to a charger plug capable of connecting with a two or three receptacle power source to convert 120V input power to DC output power. The dependent claims generally elaborate on the features and configurations of the charger plug and its interaction with the power source and electronic device.

Key Claim Terms New

Definitions of key terms used in the patent claims.

Term (Source)Support for SpecificationInterpretation
Charger plug face area
(Claim 1)		“Referring initially to FIGS. 1-4, a plug 10 having a reduced package size and improved manufacturing is illustrated, the plug 10 preferably being a AC to DC charger plug for converting input electrical power to output electrical power, thereby providing charging power to rechargeable portable electronic devices or the like.”The area defined by the front wall of the charger plug housing.
Dc connector
(Claim 1)		“In the present form, the components 32 include a connector 36 for coupling with a removable power cord 37, the power cord 37 in turn able to be coupled to an electronic device (not shown) for providing the reduced voltage DC power to the electronic device. When assembled, the connector 36 is positioned at a rear end 40 of the housing 14, and the housing 14 is preferably tapered from lateral sides 42 and from upper and lower sides 44 towards a connector opening 46 configured in registry with the connector 36 to provide access to the connector 36.”A connector on the charger plug that is designed to receive a power cord plug end for transmitting DC power to a rechargeable electronic device.
Housing outer profile
(Claim 1)		“In the present form, the housing 14 is a clamshell-type housing having upper and lower halves 22 and 24. The internal circuitry 18 and blades 12 are assembled into one of the halves 22, 24, and the halves 22, 24, are then secured together such as by electronic welding or by a snap-fit, as are known in the art.”The shape defined by the perimeter of the front wall of the charger plug and the plug body extending rearward from the front wall.
Prong portions
(Claim 1)		“As can be seen the blade 12 includes a prong portion 50 with a size and shape known in the art to include a beveled terminus 52 and a bore 54. The blade 12 is generally formed integral as a unitary item and, preferably, is a simple cut and stamped component.”The part of the blade members that are designed to be inserted into the receptacle openings of a power source.
Separate blade members
(Claim 1)		“As can be seen, the plug 10 benefits from a structure and method of assembly provided by an input assembly 11 which, in the present form, includes a pair of blades 12 having prong portions 50, discussed below. The blades 12 are received by a housing 14, and the plug 10 further includes spring contacts 16 for electrically connecting the blades 12 with internal circuitry 18 of the plug 10.”Two distinct, individual blades that are part of the charger plug's input assembly. Each blade has a prong portion for connecting to a power outlet.

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USRE48794

VOLSTAR TECH INC
Application Number
US16209373
Filing Date
Dec 4, 2018
Status
Granted
Expiry Date
May 21, 2028
External Links
Slate, USPTO, Google Patents