Abstract: An apparatus for controlling a drive mechanism of a panel display system includes a rotary member attached to a drive assembly, the rotary member having indicators located at known intervals that are detected to ensure that the drive assembly starts and stops at precise locations. In a preferred embodiment, the control system is applied to a panel display system that displays different scenes using an array of elongated three-sided display elements. The preferred control system includes an aluminum disk that is attached to rotate in connection with rotation of the drive assembly.

Abstract: An article handling apparatus including a holder into which an article can be lowered and from which it can be lifted and which can rotate the article about a substantially horizontal axis, the article including a projection on at least one side of the article, the holder including a member rotatable about the axis and having a radially outwardly open channel for receiving the projection when the article is lowered into position, in the channel in response to a predetermined rotary movement of the member and the article away from the loading and unloading position such that the article is securely held during rotation. The preferred use is for holding baskets of impregnated castings in an enclosure for draining, cold water washing or hot water curing.

Abstract: The sealing of small porous rigid articles by impregnation with a liquid synthetic resin impregnant and sequent curing of resin in the pores and provides a liquid (meth)acrylic ester impregnant composition comprising a free radical catalyst, an inhibitor and a higher alkyl (meth)acrylic ester and/or polyfunctional (meth)acrylic ester which has been obtained by transesterification in the presence of an organotitanium catalyst and from which the catalyst residue has not been removed. The catalyst residue has been found to improve sealing and thermal stability of the cured impregnant.

Abstract: There is disclosed an article treating apparatus particularly apparatus for pressure-impregnating or vacuum impregnating porous articles such as metal castings. A holder for the articles or a metal basket containing them is disposed in an autoclave and can be rotated about a horizontal axis. It has a horizontal through-passageway so that articles to be treated can be simultaneously loaded at one end of the passageway and unloaded at the other end of the passageway by an indexing mechanism. The indexing mechanism has a plurality of pusher arms which can be moved laterally into the path of the articles and then moved horizontally to push the articles along rails into and out of the passageway. The holder is stopped at a predetermined rotary position in which a longitudinal slot is opposite the pusher arms so that unloading and loading may be effected simultaneously with a single movement of the indexing mechanism, a pusher arm passing completely through the slot.

Abstract: A pressure vessel for use in impregnating porous articles comprising a support member for the articles, slidable between an upper position for degassing the articles and a lower position for impregnating the articles, a release mechanism operable from outside the pressure vessel to permit the support member to descend from the upper position to the lower position under gravity, and damping means at least partially within the pressure vessel for controlling descent of the support member.

Abstract: The invention provides an in-line method of impregnating a porous article, particularly a metal casting, which comprises placing the article on a support, placing a cover thereover in sealing relation with support to define an impregnation chamber, applying a reduced pressure to the cover at the upper part thereof, admitting impregnant to the chamber until it at least covers the pores, allowing the pressure to rise to substantially atmospheric, removing excess impregnant from the chamber, and removing the cover from the support. Such a method permits impregnation using a conveyor line system.

Abstract: A method of impregnating a porous article with impregnant to seal the pores thereof, which comprises placing the article in a vessel, evacuating the vessel to withdraw air from the pores, releasing the vacuum with the pores beneath the surface of a liquid impregnant in the vessel, removing excess impregnant from the vessel, washing excess impregnant from the surface of the article by supplying washing fluid to the vessel, removing the fluid from the vessel, heating the article while still within the vessel to effect curing of the impregnant within the pores, and removing the impregnated article from the vessel.

Abstract: This invention relates to the impregnation of rigid porous articles, particularly metal castings. In its preferred form the impregnant is a liquid mixture of monofunctional (meth)acrylic ester and a relatively small proportion of polyfunctional (meth)acrylic ester to provide a cross linked product on curing and to facilitate washing of the casting with water and an emulsifier. A peroxy or other free radical catalyst such as AZBN is associated in the impregnant with an inhibitor such as a hydroquinone derivative so that curing can be effected at a temperature of 90.degree. C. within 3 to 15 minutes. Curing is preferably effected by immersion in a hot water bath.