Abstract: Proximity sensor for determining the distance between a reflective surface and the sensor utilizes two output light guides positioned with the receiving end of one guide closer to the reflective surface than that of the other. When the surface is close to the guide ends a relatively greater intensity of light will be reflected to the second guide; when the surface is further away a relatively greater intensity of light will be reflected to the first guide. At a predetermined intermediate null position the reflected light intensities will be equal. The device has uses, inter alia, in accurately positioning objects without wear-producing contact, e.g. in numerically controlled machine tool operations; thickness sensing or thickness controlling using single or dual sensors; force sensing; liquid level indication; meter relay actuation; rotational limitation, and the like.

Abstract: Apparatus for mixing products within a generally flattened, flexible package having opposite side walls, comprising a support surface adapted to support one side wall of a package and mixing means adapted to contact an opposite side wall of a package on the support surface, the mixing means and support surface being mounted for rotation relatively to each other about an axis generally perpendicular to and intersecting the support surface. The mixing means includes package contacting means extending from the axis and generally parallel to the support surface and operating means for rotating the mixing means and support surface relatively to one another about the axis for mixing a product within the package during such rotation.