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Ram-Type Piston With Integrated, Automated Bleed Valve for High Viscosity Fluids

IP.com Disclosure Number: IPCOM000120811D
Original Publication Date: 1991-Jun-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 70K

Publishing Venue

IBM

Related People

Clark, T: AUTHOR [+3]

Abstract

A mechanism is disclosed which automatically bleeds high viscosity fluids from a standardized dispensing tube through a ram-type piston. The mechanism can be actuated anywhere along the travel of the piston, even within the confines of the dispensing tube. (Image Omitted)

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Ram-Type Piston With Integrated, Automated Bleed Valve for High Viscosity
Fluids

      A mechanism is disclosed which automatically bleeds high
viscosity fluids from a standardized dispensing tube through a
ram-type piston.  The mechanism can be actuated anywhere along the
travel of the piston, even within the confines of the dispensing
tube.

                            (Image Omitted)

      The device described below is used in a tool that dispenses
thermal grease or paste on to the backsides of protective caps prior
to enclosing semiconductor modules. Paste tubes are loaded onto the
tool by the operator and are pressurized by a ram connected to a
large bore air cylinder. Air becomes trapped inside the tube when the
ram is initially inserted, and this air must be bled from the system
in order for the tool to function properly.  This invention provides
the bleeding functions and can do so at any point in the travel of
the ram without operator intervention.

      To achieve the bleeding process, the paste ram is bored out and
a smaller linear piston is installed.  When actuated, this piston
opens and closes a port at the bottom of the ram using a seating
ball.  Access for the piston bore inside the ram is made via vertical
passageways from the surface of the ram.  Paste that is bled also
travels vertically to the top ram where it is carried off by a
plastic line to an excess paste depositor.

      The basic operation is as f...