Abstract: The invention concerns a blocking device for obstructing the opening of an inlet pipe in a sewer manhole, so that rats and like rodents are restrained. The blocking device comprises a ball or pear-shaped floatable blocking body for automatic blocking of the pipe opening by gravity when there is no flow of waste material into the manhole, said blocking body being pivotally suspended from a supporting means which by means of a tightening member is secured above the pipe opening by being wedged between opposite wall portions of the manhole. The blocking device also has a stopping means for limiting the penetration depth of said blocking body in the inlet pipe.

Abstract: A grease separating system includes four successive chambers. The heated, emulsified grease is passed through a solids retention box into an inlet chamber where cool water is sprayed onto the emulsified grease. This mixture is passed through a connecting chamber, and then over baffles at the entrance of a collection chamber. The grease having been separated from its emulsified state rises to the top of the mixture in the collection chamber, and the water passes into a discharge chamber and in to the connected sewer system. After successive operations, the floated grease is sensed when it reaches a predetermined level, and an alarm is sounded to indicate that the accumulated grease should be removed.

Abstract: An axially rigid, tubular grid is fitted over a conduit having a single longitudinal row of apertures; a fine mesh flexible tube is fitted over the grid; an end cap closes one end of the conduit and seals the tube thereto; and a tubular connection is threaded onto the other end of the conduit to seal the adjacent portion of the flexible tube to the conduit.

Abstract: A vibratory coolant strainer for a cutting tool coolant supply system for a machine tool. A strainer screen assembly is rotatably mounted on a coolant system fixed supply pipe. A yoke is attached to the upper section of the strainer screen assembly and it is rapidly vibrated by a plural lobe cam which imparts a rapid vibratory or rotary oscillating motion to the strainer screen assembly so as to free it of metal chips and other dirt. The plural lobe cam is secured to a rotatably mounted shaft which is operatively supported in a housing attached to the supply pipe. The cam shaft may be driven by a suitable motor, or a belt or chain from a power source which is internal or external of the machine tool.