Abstract: A water aerator is provided that has a rigid support plate that in the operating position is disposed essentially horizontally. The support plate has a practically planar upper surface and at least one aperture for air. An elastic plate of elastomeric material is disposed on the upper surface of the support plate. The elastic plate is provided with a plurality of fine slits that can be widened by air that is introduced between the support plate and the elastic plate. The elastic plate has a rim that sealingly surrounds the downwardly directed rim of the support plate to be secured thereto in a hook-type manner.

Abstract: A method of producing a plastic pin, including a bowling pin, having a cellular and/or porous core that is surrounded by a solid-walled, noncellular and nonporous shell. The shell is initially produced as a whole body in a mold. While the material of the shell is not yet hardened and is still deformable, an insert is introduced into the narrowed neck portion of the shell, in a direction axial relative thereto, in such a way that the insert displaces an inner layer of the shell, dividing the hollow interior of the shell into an upper and a lower chamber and producing a fixed connection with the material of the shell. Material for the core, with such material being provided with an expanding agent, is then introduced into the shell, and after the shell and the core have set, the mold is removed.

Abstract: A bowling pin of synthetic material, and a method of producing the same, are provided. The pin has a core that is provided with pockets or cells, and also has a sheathing of solid wall construction. To achieve a particularly compact and thick outer shell, the core is also provided with an outer layer of solid wall construction that is disposed between the inner body of the core and the sheathing, and is fused with the sheathing. To provide the core with such an outer wall, the mold that receives the material that contains an expansion agent is cooled on the outside to such an extent that the expansion agent cannot become effective in the outer area.

Abstract: A bowling of synthetic material is provided. The pin has a core that is provided with pockets or cells, and also has a sheathing of solid wall construction. To achieve a particularly compact and thick outer shell, the core is also provided with an outer layer of solid wall construction that is disposed between the inner body of the core and the sheathing, and is fused with the sheathing. To provide the core with such an outer wall, the mold that receives the material that contains an expansion agent is cooled on the outside to such an extent that the expansion agent cannot become effective in the outer area.

Abstract: Provision is made to proceed on the basis of a revolving, inextensible band, especially a track for vehicles, that is made endless via a connecting mechanism, with the outer surface of the band body being provided with ribs, and with the connecting mechanism being disposed between the ribs on the band body. In order to preclude damage to the connecting mechanism during rotation of the band, for example by striking the roadway, in the region of the zone of connection of the band body provision is made for additional projections that project above the connecting mechanism, and preferably have a height that corresponds essentially to that of the ribs.

Abstract: An apparatus for aerating water, including rigid supporting pipes, which serve to supply air, and covers which are disposed on the supporting pipes close thereto and are provided with a plurality of resiliently expandable slits. The supporting pipes, together with their covers, are disposed virtually in a vertical plane one above the other in a horizontal parallel position. The covers and/or the supporting pipes have air supply openings of different sizes such that these openings, when viewed from bottom to top, become gradually smaller in order to ensure that, when the air supply means is common to all of the supporting pipes and covers of an apparatus, the air throughput quantities are at least substantially identical in size at the different vertical positions of the supporting pipes and covers.

Abstract: A belt with rods for a rod belt conveyor. Transversely extending rods are secured to the side bands. In order not to have to further prepare the rods and the bands, yet to provide a secure connection, a holder extends about the rod ends, with the ends of the holder being held by clamps that are forced into the non-prepared bands. The clamps or securing elements could at the same time also be formed as holders and could thereby form the aforementioned holder.

Abstract: A device for aerating water, and including a rigid, essentially planar support member, and thereupon a plate of elastomeric material that is provided with fine slits for the release of air. The underside of the support member is provided with one or more connectors for supplying air between the support member and the plate. The rim of the plate is pressed in an airtight manner from above against the support member by a profiled annular frame that is secured by screws to the support member. The frame has a flat portion via which it rests against the plate, and also has an annular reinforcing rib that is directed upwardly away from the plate, so that the frame has an L-shaped or T-shaped cross-sectional shape. The frame also has an outer peripheral portion for receiving fastening screws.

Abstract: A connector for rotating belt-like members that are subjected to tension. The belt-like members are provided with reinforcements that form a unit. Furthermore, the members are made essentially of rubber or rubberlike materials, and have two ends. Two U-shaped fittings that are interconnected in an articulated manner are provided, with each fitting being provided with two legs having surfaces that face one another. In the mounted state, a given one of the ends of a belt-like member is disposed between the facing surfaces of the legs of a given fitting, whereby the fitting is secured to the belt-like member via fasteners. The facing surfaces of the legs are each furthermore provided with projections that extend transverse to the direction in which the member rotates. One of the projections of a given one of the legs is disposed across from the space between two projections of the facing leg.