Coupling and a piston for use in the same

Details Coupling and a piston for use in the same Coupling and a piston for use in the same

2000-06-13

2001-12-04

Shaver, Kevin (Department: 3754)

Fluid handling

Systems

Flow path with serial valves and/or closures

C222S321900, C251S149600

Reexamination Certificate

active

06325099

ABSTRACT:

FIELD OF THE INVENTION
The present invention pertains to a coupling for interconnecting two hollow bodies, such as a container and a tube.
BACKGROUND OF THE INVENTION
Such a coupling is known from, e.g., European patent application 0 270 302, which describes a coupling for a liquid product packaging and dispensing assembly in which liquid is pumped from a container via the coupling through a tube to the point of use. The coupling has a first interconnectable member with a hollow post and a biased sleeve closing openings in the hollow post and a second interconnectable member with a hollow sheath and a biased piston closing an opening at the end of the sheath. The parts are configured so that, upon connection, the post unseats the piston while the sheath displaces the sleeve, thereby allowing liquid flow.
In one form, the container may be collapsible and is preferably situated inside a box for convenience during storage and transport. EP 0 270 302 mentions that a problem arising with such containers resides in that upon uncoupling the container from the tube, residues of the liquid which has been flowing through the coupling between them are apt to be spilled. This can be hazardous if the liquid is noxious, for example if the liquid is a very alkaline product such as industrial mechanical dishwashing liquid.
The coupling according to EP 270 302 indeed has the advantage that when it is disconnected both hollow bodies are sealed, and that it reduces spillage. However, it appeared that after disconnection liquid residues often stay behind on the end of the hollow post and/or on the piston head. These residues of course can be harmful to the persons working with the coupling. Further, the said residues solidify and over time form a crust on the piston head, which crust interferes with the tightness of the seal between the piston head and its seat.
The invention aims to provide a coupling of the above-mentioned type wherein the above-mentioned disadvantages are substantially obviated.
SUMMARY OF THE INVENTION
To this end, the coupling of the invention is characterised in that, upon connection of the members, the central area of the surface of the piston head initially contacts just the central area of the surface of the closed end of the post and the established contact area subsequently expands away from its centre thus displacing any fluid residing between the said surfaces.
It is preferred that the surface of the piston head is convex and the surface of the closed end of the post is concave, the radius of curvature of the piston head being smaller than the radius of curvature of the closed end of the post. Also, the piston head and/or the closed end of the post preferably is made of a flexible material.
If the piston is gas permeable and liquid impermeable, substantial underpressures in the container and malfunctions resulting from such underpressures, such as interruption of the flow, are avoided.
It will generally be desirable for the various parts to be co-axial, that is to say for the sheath and piston to be co-axial and for the sleeve and post to be co-axial and, moreover, for all four of them to lie on a common axis when coupled.
The invention will be further explained by reference to the drawings in which an embodiment of a coupling of the invention is schematically shown.


REFERENCES:
patent: 2509444 (1950-05-01), Mitchell
patent: 3568736 (1971-03-01), Linch et al.
patent: 3972387 (1976-08-01), Braun
patent: 4119111 (1978-10-01), Allread
patent: 4221235 (1980-09-01), Maldavs
patent: 4582295 (1986-04-01), Kugler et al.
patent: 4609004 (1986-09-01), Greene et al.
patent: 4949745 (1990-08-01), McKeon
patent: 4951710 (1990-08-01), Kotake
patent: 5211197 (1993-05-01), Marrison et al.
patent: 5346177 (1994-09-01), Paulsen et al.
patent: 5425404 (1995-06-01), Dyer
patent: 5450875 (1995-09-01), Chichester et al.
patent: 5544858 (1996-08-01), Rogers et al.
patent: 6095190 (2000-08-01), Wilcox et al.
patent: 0 270 302 (1988-06-01), None
patent: 0 448 922 (1991-10-01), None
patent: 0 675 072 (1995-10-01), None
European Search Report dated Nov. 5, 1999.

Affiliated with

Also associated with

Rating

Coupling and a piston for use in the same does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Coupling and a piston for use in the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coupling and a piston for use in the same will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2561535