Minnesota Mining and Manufacturing Company

3m Innovative Properties Company

Alfred D Nelson

Merlin R Jahnke

Brian D Johnson

Thomas L Morse

Garold L Goken

Larry E Espelien

A method of stamping a part from an elongated strip of multi-layered material. The multi-layered material includes a viscoelastic intermediate layer, and upper and lower layers that are relatively rigid with respect to the intermediate layer. The method includes providing symmetrically aligned top and bottom punches each including a material displacement edge corresponding with a desired shape of the part. Each of the material displacement edges are defined by a rake surface and a part interface surface that combine to form a positive rake angle. The strip is positioned between the top and bottom punches. The top and bottom punches then shear a portion of the upper and lower layers, respectively. More particularly, symmetrical groove patterns are formed in the upper and lower layers, defining a perimeter of the part. The part is then removed from the strip along the perimeter.

Method for stamping a part from a multi-layered strip

Microwave oven window having a microwave-blocking screen, an interior plastic film and a pressure-sensitive adhesive layer bonding the plastic film to the screen over the full area of the screen but substantially not penetrating into the openings of the screen.

Microwave oven window

Microwave oven window comprising two transparent panels, an intermediate microwave-blocking screen and a transparent thermoplastic adhesive filling the space between the panels. The interior panel is very thin and the thickness of the thermoplastic adhesive panel barely exceeds that of the screen. The thinness of the interior panel plus adjacent adhesive minimizes the leakage of microwaves.

Microwave oven window construction

This invention pertains to a fuel cell which comprises a case, positive and negative electrodes inserted therein and electrolyte filling the inner space between the electrodes. Means for introducing an oxidizing gas into the space behind one electrode and a fuel behind the other are provided. A porous membrane substantially parallel to the electrodes comprising a self-supporting compressible porous fibrous mat of randomly dispersed and entangled micro-fibers of a high molecular weight thermoplastic polymer impregnated with said electrolyte occupies said inner space. This porous membrane permits communication of electrolyte between electrodes but prevents passage of small bubbles of oxidizing or fuel gases.

Matrix construction for fuel cells

Adhesively bonded rail joint which is quick to assemble and easy to dismantle and reassemble. The face of each joint bar of the rail joint has a layer of thermoplastic adhesive which upon moderate heating adheres strongly under moderate pressure to conforming surfaces of the rail ends. Because the thermoplastic adhesive does not cure, the joint bars are easily separated from the rails by reheating the adhesive and can be reapplied or used as part of a new rail joint.

Growing community of inventors

Stillwater, MN, United States of America

Alfred D Nelson