Abstract: A power and free conveyor has a stop lug on the carrier body adapted to abut a stop member movable into the path of the carrier along the conveyor track to arrest movement of the carrier, the stop member serving to disengage the driving dog from the power chain prior to abutting the stop lug. The stop lug is spaced rearwardly of the driving dog a distance exceeding rebound of the carrier whereby accidental re-engagement of the driving dog with the power chain is avoided. The stop lug is positioned to engage the power chain pusher lug on a decline in the conveyor system should the hold-back dog fail to do so, thereby preventing a runaway.

Abstract: An apparatus for mounting steps on the inner wall surface of a manhole section comprises implanting the steps in the section while the same is still green and following removal of the inner form but before removal of the outer form, positioning each step in confronting relation with the manhole section and thereupon smoothly and uniformly, without vibration and hammering, pushing the step into the concrete and compacting the concrete around the implanted step. The apparatus may be portable and shifted into the manhole section through an end thereof after the inner form has been removed but prior to removal of the outer form, and positioned against the base ring at opposite inside diameters thereof and engaging the outer form at the top of the manhole section and while thus engaged urging the step into the manhole section as aforesaid. Alternatively the apparatus may be stationary and the manhole section temporarily moved thereto and supported thereon during step implanting.

Abstract: A rotary mechanical vacuum pump has a pump chamber formed of aluminum which has been treated by hard anodizing the working surfaces of the pump chamber and the lapped mating surfaces between the parts surrounding the chamber, with a high vacuum grease applied to such mating surfaces and providing an effective seal against leakage between the pump chamber and the ambient atmosphere.

Abstract: A gas scrubber of the wet collector type induces a gas flow under a negative pressure through a housing between a gas inlet and a gas outlet. The housing includes a scrubbing liquid reservoir, and means in the housing cooperating therewith to define a gas scrubbing zone above the reservoir and through which the gas moves. A tunnel open to the atmosphere extends transversely of the housing adjacent the scrubbing zone with the interior of the tunnel being at atmospheric pressure, which is higher than the gas pressure in the housing. A spinner shaft in the tunnel projects through the tunnel wall and carries a liquid diffusing spinner in the scrubbing zone. The shaft is solely supported by bearing means in the tunnel. A pump draws liquid from the reservoir and directs it against the spinner to diffuse the liquid across the scrubbing zone. By virtue of the higher pressure in the tunnel the bearings supporting the spinner are not contaminated by the scrubbing action in the housing.

Abstract: A molding assembly including a resilient pad affixed to a support, and a hollow molding device overlying the pad, with a fastener interconnecting the molding device to the pad, and wherein the resilient pad is provided with a longitudinal slit, and the fastener has a body portion interfitting within the molding and an integral tongue-like extension projecting into the slit in the pad, the slit being expanded by the entrance of the extension and both having cooperating surfaces extending laterally with respect to the plane of the slit for interlocking engagement with one another to retain the fastener to the pad.