Molding processes and tool therefor

• US 7,997,891 B2
• Filed: 04/11/2008
• Issued: 08/16/2011
• Est. Priority Date: 04/12/2007
• Status: Active Grant

• Current Assignee: Purdue Research Foundation (The Trustees of Purdue University (d/b/a Purdue University))
• Original Assignee: Purdue Research Foundation (The Trustees of Purdue University (d/b/a Purdue University))
• Inventors: Gallagher, Jeffery M., Cipra, Raymond J., Siegmund, Thomas H.
• Primary Examiner(s): Lee; Edmund H.
• Application Number:
  US12/101,697
• Publication Number:
  US 20080251975A1
• Time in Patent Office: 1,222 Days
• Field of Search: None
• US Class Current: 425/388
• CPC Class Codes: B29C 33/0011 thin-walled moulds
• CPC Class Codes: B29C 33/18 using vacuum
• CPC Class Codes: B29C 33/302 Assembling a large number of mould elements to constitute one cavity
• CPC Class Codes: B29C 51/10 Forming by pressure difference, e.g. vacuum
• CPC Class Codes: B29C 70/382 Automated fiber placement [AFP]
• CPC Class Codes: B29C 70/48 and impregnating the reinforcements in the closed mould, e.g. resin transfer moulding [RTM] , e.g. by vacuum
• CPC Class Codes: B29K 2707/04 Carbon
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing

Abstract

A molding process and apparatus suitable for use in molding processes, including rapid prototyping processes and short run production processes. The molding process and apparatus entail the use of a reconfigurable screen tool having a housing defining a manifold cavity and a plurality of substantially parallel pins, each having a head protruding from the housing and a shank protruding into the housing. The heads of the pins define a screen surface through which air is able to flow, for example, through gaps between adjacent heads or through internal passages within the pins. The process further includes axially moving the pins to configure the screen surface, preventing further axial movement of the pins relative to each other, and then drawing a vacuum within the manifold cavity and creating a vacuum at the screen surface.

Claims

1. An apparatus having a reconfigurable screen tool comprising:

a housing defining a manifold cavity;

a plurality of pins, each pin having a head protruding from the housing and a shank protruding into the housing, the pins being substantially parallel to each other and axially movable relative to each other and relative to the housing, the heads of the pins defining a screen surface through which air is able to flow;

means for axially moving the pins relative to each other to configure the screen surface by engaging the heads of the pins to cause axial movement thereof, wherein the axial moving means comprises a robotic-controlled end effector sized to simultaneously contact the heads of a plurality of the pins but not simultaneously contact the heads of all of the pins, and the axial moving means causes the robotic-controlled end effector to simultaneously contact the heads of the plurality of pins to simultaneously sculpt the plurality of pins;

means other than the axial moving means for preventing axial movement of the pins relative to each other by engaging the shanks of the pins;

means for drawing a vacuum within the manifold cavity and creating a vacuum at the screen surface; and

optionally an interpolator adapted to be placed on the screen surface for defining a surface that is smoother than the screen surface.

2. The apparatus according to claim 1, wherein the axial movement preventing means comprises multiple tiers of elongate elements between the shanks of the pins, and means for causing the elongate elements of each tier to apply a traverse load to the shanks.

3. The apparatus according to claim 1, further comprising a discrete deposition print head adapted to locally deposit discrete quantities of fibers on the screen surface.

4. The apparatus according to claim 1, wherein the reconfigurable screen tool is a first of at least two reconfigurable screen tools according to claim 1, the apparatus further comprising means for constraining movement of the at least two reconfigurable screen tools relative to each other when the screen surfaces thereof are facing each other to define a mold cavity therebetween.

5. The apparatus according to claim 4, further comprising means for drawing a vacuum within the mold cavity.

6. The apparatus according to claim 5, wherein the interpolator is placed on the screen surface of each of the reconfigurable screen tools.

7. The apparatus according to claim 1, wherein at least one of the pins has an internal passage open at the head thereof, and the drawings means is further operable to draw a vacuum through the internal passage to create the vacuum at the screen surface.