Dispensing – With discharge assistant – With movable nozzle interconnected therewith
Reexamination Certificate
2000-07-31
2001-08-28
Derakshani, Philippe (Department: 3754)
Dispensing
With discharge assistant
With movable nozzle interconnected therewith
C222S341000
Reexamination Certificate
active
06279785
ABSTRACT:
The present invention relates to a pump for mounting on a receptacle, the pump being of the type comprising two parts which are movable with respect to each other defining between them a variable-volume pump chamber, the first part comprising a wall defining a fluid inlet passage, via which the fluid contained in the receptacle can reach the pump chamber, the second part comprising a wall defining a fluid outlet passage via which the fluid contained in the pump chamber can leave, the pump comprising a membrane having a first portion disposed on the outer side of the wall defining the inlet passage, such that pressure in the pump chamber applies said first portion to said wall to obstruct said inlet passage when the volume of the pump chamber is reduced.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 5,267,673 describes a pump of the above type. In that known pump, the membrane comprises a portion disposed on the outer side of the wall defining the outlet passage and is deflected from it under the effect of an overpressure in the pump chamber.
With such a configuration, the fluid is not dispensed along the pump axis, which can be a problem when the pump is intended to be mounted over a distribution nozzle.
OBJECTS AND SUMMARY OF THE INVENTION
There is a need to provide a pump of that type which is both cheaper to manufacture and which functions reliably.
In the novel pump of the invention the membrane comprises a second portion disposed on the inner side of the wall defining the outlet passage, such that an underpressure in the pump chamber applies said second portion to said wall to obstruct said outlet passage when the volume of the pump chamber increases.
The invention thus provides a pump comprising a reduced number of component parts which is easy to manufacture and which functions reliably.
Further, the fluid can be dispensed along the axis of the pump, which can be advantageous.
In a particular embodiment, the first part of the pump is stationary and integral with the receptacle.
In a preferred embodiment, the membrane is integral with the first part of the pump and the second portion of the membrane can be displaced axially with respect to the wall defining the outlet passage, said passage being obstructed when the volume of the pump chamber increases.
In a variant, the membrane is integral with the second part of the pump and the first portion of the membrane can displace axially with respect to the wall defining the inlet passage and obstruct said passage when the volume of the pump chamber reduces.
In a further preferred embodiment, the first and second portions of the membrane are tubular.
Preferably, the first and second portions of the membrane form a cylinder, advantageously a symmetrical cylindrical body of revolution.
The membrane is easier to assemble as no angular positioning is required.
In a particular embodiment, the wall defining the inlet passage is tubular and the first portion of the membrane is disposed around it.
In a still further particular embodiment, the wall defining the outlet passage is also tubular and the second portion of the membrane is inserted inside it.
In a yet still further particular embodiment, the wall defining the outlet passage is a cylindrical body of revolution, as is the outer surface of the second portion of the membrane facing it.
In a yet still further particular embodiment, the wall defining the inlet passage is a cylindrical body of revolution, and comprises at least one lateral opening, and the inner surface of the first portion of the membrane facing it is a cylindrical body of revolution.
In a preferred embodiment, the membrane comprises a transverse partition between its first and second portions.
In a yet still further preferred embodiment, said transverse partition bears axially on the wall defining the inlet passage.
Advantageously, a resilient return means is provided to return the second part of the pump to an initial position in which the volume of the pump chamber is a maximum.
This resilient return means is preferably formed in a single piece by molding a plastics material with the membrane.
This avoids the need for a metal helical spring which would result in extra cost and could cause problems regarding compatibility with the fluid to be distributed.
In a particular embodiment, the resilient return means comprises a flange against which the wall defining the outlet passage can bear, and a transverse partition which can stretch elastically when the wall defining the outlet passage is displaced.
In a particular embodiment, the membrane comprises a symmetrical body of revolution with an axial cross section in the shape of an H.
In a yet still further particular embodiment, the edge of the membrane comprises an L-shaped annular flange against which the wall defining the outlet passage bears.
Such a membrane can readily be produced by molding.
The invention also provides a receptacle equipped with a pump in accordance with the invention.
REFERENCES:
patent: 4875604 (1989-10-01), Czech
patent: 5267673 (1993-12-01), Crosnier et al.
patent: 5918778 (1999-07-01), Schultz
patent: EP 0 470 906 A1 (1992-02-01), None
Derakshani Philippe
L'Oreal
Oliff & Berridg,e PLC
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