Abstract: The invention relates to the production of concrete roof tiles in an extrusion process, in which a continuous layer of fresh concrete is deposited on pallets supplied in a continuous row to a depositing apparatus and is subsequently compacted by means of a shaping roller and slipper and, if appropriate, profiled, and then the compacted layer of fresh concrete is cut at a cutting station into roof-tile moldings of equal length with a rear edge and a front edge, and the front edge is trimmed. To increase the weathering resistance and the strength of the front edge of the concrete roof tiles produced in this way, and to reduce the efflorescence which occurs in this region, a rounding or bevel starting from the lower cut edge adjacent to the pallet and extending up to the top side of the roof-tile moldings is produced, preferably in steps, on the front edge as a result of a compacting of material.

Abstract: In this ridge or hip covering, flexible sealing strips (9) are arranged between the covering caps (7) fastened to the ridge or hip board (6) of the roof structure and the roofing tiles (3).In order that the sealing strips (9) can universally be used with the most different roofing tiles and roof pitches, they comprise a flexible supporting strip (10) which is provided on one or both longitudinal edges (11) with a comblike edge part (12) of elastically deformable material, the teeth (12a) of which are connected with an edge strip (13) of flexible material which bridges the tooth spaces allowing the teeth to spread, whereby the outer longitudinal edge (14) of the edge strip adapts to the contour of the upper side of the roofing tiles (3) lying below it.If with the sealing strips (9) both a sealing against rain and driving snow and a ventilation of the roof space is to be made possible, an air-permeable bonded fabric, in particular of polyester or polyamide fibres, can be used for the edge strip (13).

Abstract: A sealing element is provided which is suitable for sealing flat roofs and engineering structures. The sealing element is made of a water-resistant elastomer or plastomer, and comprises a lamelliform structure of substantially circular shape having from four to six waves, inclusively, distributed radially throughout the structure and around the entire circumference of the structure, the amplitudes of which waves increase regularly from the center of the structure towards the circumference. The undulations enable the sealing element to have an effective surface covering more than 360.degree. without straining any region of the element.

Abstract: A self-adhesive tape particularly suitable for use in the building industry for joining and sealing PVC sheets, comprising 100 parts by weight of a vinyl chloride/vinylisobutylether copolymer, from 100 to 400 parts by weight of a mixture of nitrile rubber and a polyvinylchloride homopolymer, from 60 to 230 parts by weight of a plasticizer consisting of one or more esters of phthalic acid, and from 4 to 70 parts by weight of a resinous plasticizer which is an aromatic polyether, an epoxy resin or a mixture thereof, and which imparts adhesive properties to the composition.

Abstract: A sealing sheeting for the construction industry with elastomeric properties at elevated temperatures. Further, the invention concerns the production method for such sheeting.

Abstract: An injection molding machine for plastic material comprising an injection cylinder; a displaceable element axially disposed in the cylinder, one of the cylinder and displaceable element being movable with respect to the other; an injection nozzle on one end of the injection cylinder; a feed device including a feed hopper and a plunger reciprocally mounted in said hopper in communication with the other end of the cylinder; a pressure block between the feed device and the other end of the cylinders and a substantially continuously curving passage in the pressure block.

Abstract: An injection molding machine comprising an injection cylinder; a displacement element axially disposed in the injection cylinder; one of the cylinder and displacement element being movable with respect to the other; an injection nozzle on one end of the injection cylinder and a feed device including a feed hopper and a plunger reciprocally mounted in the hopper on the other end of the cylinder; a pressure source for driving the plunger; and switches for varying the working position of the plunger, the plunger stroke, the stroke frequency of the plunger and the pressure of the pressure medium.