Patents
Patents for B28B 21 - Methods or machines specially adapted for the production of tubular articles (3,281)
09/1991
09/25/1991CN1054758A Method for making float stone stovepipe
09/24/1991US5051223 Method for the production of concrete pipes
09/05/1991WO1991013214A1 Manholes and inspection chambers
09/03/1991CA1288208C Method and apparatus for forming shaped pieces of insulation
08/1991
08/27/1991US5043116 Process for producing one end-sealed ceramic double wall-structural tubes
08/21/1991EP0442587A1 Moulding apparatus
08/20/1991US5040968 Device for manufacturing concrete parts
08/07/1991EP0440591A2 Method for producing a concrete pillar
08/06/1991US5037600 Method of applying a polyolefin coating to pipe
07/1991
07/30/1991WO1991011653A1 A method and apparatus for coating the outer surface of an elongated body with a layer of concrete
07/30/1991US5035850 Casting A Mixture Of A Hydrophilic Resin And A Hardener To Form A Corrosion Protective Resin Layer On An Inner Surface
07/24/1991CN2081338U Thin cement well pipe
07/17/1991EP0437163A2 Densifier and homogenizing cylinder for making sheets and pipes from asbestos cement
07/02/1991US5028368 Method of forming lined pipe
06/1991
06/26/1991CN2079559U Vertical screw extruding machine for tube
06/12/1991EP0431055A1 Spacer which can be embedded in concrete
06/06/1991DE3939447A1 Concrete drain-pipe prodn. system - involves rotating inner cylindrical mould and bar-shaped vibrating member
05/1991
05/29/1991EP0429389A2 Process of and apparatus for forming concrete pipe with step
05/22/1991EP0428195A1 A process of protecting the spigot of concrete pipes
05/21/1991US5016348 Process for the manufacture of a tubular crankshaft
05/14/1991CA1284020C Concrete pipe making machine
05/08/1991CN2076472U Continuous shaper for low-pressure water delivering soil-cement pipe
05/07/1991US5013501 Branched pipes
04/1991
04/16/1991US5008045 Means for removal of heat; non-cylindrical shapes for dense compaction
04/11/1991DE3932759A1 Mould work and formwork for circular concrete sections - incorporates projecting in-built iron components and uses clamps and sectional components at insert positions
03/1991
03/06/1991EP0215901B1 High speed pipe lining method and apparatus
02/1991
02/26/1991US4996013 Method for rapid molding of elongate concrete articles
02/12/1991US4992640 Wire electric discharge machining apparatus
02/06/1991EP0227753B1 Rapid moulding of hollow elongate concrete articles
01/1991
01/31/1991DE4022266A1 Automatic feeding of sealing rings onto pipe sockets - in which seal holder automatically drops and pushes seals onto sockets through separate stop and holding rings
01/24/1991DE4022089A1 Casting concrete pipes by vibration process - uses cylindrical mould with vibrators mounted inside mould core
01/16/1991EP0407786A1 Transfer tube with insitu heater
01/16/1991EP0407632A1 Process for making concrete pipes and press therefor
01/10/1991CA2012235A1 Transfer tube with insitu heater
01/09/1991EP0406612A1 Process and equipment for realizing reinforced concrete pipes
01/02/1991CN1048188A Concrete pipe-manufacturing machine
01/02/1991CN1048187A Construction process of continuously cast-in-situ concrete pipeline and its cast spreader
01/02/1991CA1278535C Prestressed concrete articles
01/01/1991US4981740 Acid resistant concrete articles, especially sulfur concrete pipes, and a method of manufacturing said articles
12/1990
12/19/1990CN2067639U Machine for producing concrete pipe
12/12/1990CN1010755B Underground concrete-pipe extruder
12/11/1990US4976291 Cylindrical concrete layer, corrosion resistance protective coating
11/1990
11/21/1990CN1047047A Production technology for inorganic composite material water transport pipe
11/15/1990WO1990013405A1 Aluminium oxide tubes and process for manufacturing them
11/15/1990DE3915428A1 Aluminiumoxidrohre und verfahren zu ihrer herstellung Alumina tubes and process for their production
11/14/1990EP0396694A1 Process for manufacturing an annular concrete workpiece, in particular a shaft ring
10/1990
10/30/1990CA1275617C Coated metal pipe having bending capability
10/24/1990EP0393433A2 Process for lining the inner wall of a concrete pipe and device for carrying out this process
10/24/1990CN1046306A Acid resistant concrete articles especially sulphur concrete pipes and a method of manufacturing them
10/23/1990US4965107 One end-sealed ceramic double wall-structural tubes
10/17/1990CN2063867U Self-motion double stirring extrusion
10/10/1990EP0128913B1 Plant for the continuous and automated manufacturing of agglomerated, sintered, vulcanized and pressed articles
10/10/1990CN2063473U Field continuously casting machine for concrete tube
09/1990
09/26/1990EP0389089A2 Method and apparatus for centrifugally casting hazardous waste
09/26/1990CN1045573A Special ceramic refractory annular tubes
09/23/1990CA2008836A1 Method and apparatus for centrifugally casting hazardous waste
09/20/1990DE4007189A1 Making columns, etc. for building industry - by placing longitudinally slit reinforced cylinder in half sleeve, casting e.g. concrete, fixing top half sleeve, and centrifuging
09/19/1990EP0388391A1 Method of impregnating cement products, and products produced thereby
09/19/1990EP0388347A2 Concrete pipe making machine
09/19/1990EP0302853B1 In-mold label dispenser for plastic blow molding machine
09/19/1990EP0299953B1 In-mold label dispenser of blow molding machine
09/18/1990US4957424 Concrete pipe making machine
09/13/1990CA2001399A1 Concrete pipe making machine
09/12/1990EP0386949A2 Ceramic tubes and their manufacture
09/12/1990EP0386428A2 Process and equipment for lining concrete pipes
09/11/1990WO1990010606A1 Acid resistant concrete articles, especially sulphur concrete pipes and a method of manufacturing them
09/11/1990CA2048643A1 Acid resistant concrete articles, especially sulphur concrete pipes and a method of manufacturing them
09/10/1990CA2011190A1 Ceramic tubes and their manufacture
08/1990
08/16/1990EP0382181A2 Concrete tubing reinforced with glass fibres and plastic material nets
08/15/1990CN2060496U Pipeline attatched to wall
08/08/1990EP0380474A1 Method and apparatus for coating pipes.
08/07/1990US4946082 Transfer tube with in situ heater
08/02/1990DE4002191A1 Spark erosion machine with laterally apertured vessel - delivers working fluid through gap between electrode arm and enclosing sealing sleeve
07/1990
07/19/1990DE3900873A1 Plug-in socket seal which is concreted into a pipe socket
07/17/1990US4941643 Apparatus for forming inverts and manhole assemblies and the like utilizing adjustable invert forming members joined with an intermediate flexible portion
07/04/1990CN1043551A Indoor drainage pipe and its manufacture
06/1990
06/27/1990EP0375294A2 Method of producing ceramic manifolds for thermally insulating exhaust channels
06/27/1990EP0374667A1 Process and installaton for making a composite pipe in a rotating mould
06/26/1990US4936006 Method of making prestressed concrete articles
06/26/1990CA1270624A1 Method and device for the casting of concrete products
06/23/1990CA2006518A1 Method and apparatus for producing a composite pipe in a rotating drum
05/1990
05/29/1990US4929127 Drill bit for producing drilled holes with an undercut
05/17/1990WO1990005051A1 Process for manufacturing an annular concrete workpiece, in particular a shaft ring
05/08/1990US4923655 Sealing of end faces of ceramic tubes
04/1990
04/18/1990EP0364028A1 Tubular camshaft manufacturing process
03/1990
03/14/1990EP0358256A1 A sealing and protective device for pipes
03/08/1990WO1990002234A1 Spacer which can be embedded in concrete
03/07/1990EP0356922A1 Spacer embedded in concrete
02/1990
02/07/1990EP0244404B1 A method of casting concrete objects and a form herefor
02/07/1990CN2052338U Grinding head for cement pipe making machine
01/1990
01/17/1990EP0351325A1 Apparatus for making a ring-shaped element from concrete, in particular for lining a shaft
01/17/1990CN2051155U Earthen pipe blank forming machine capable of forming multiple pipe simultaneously
01/03/1990CN2050371U Shapping arrangement by rotating extrusion for concrete inserting pipes
12/1989
12/27/1989EP0347962A2 Tube having a structure made from cement, method and machine for manufacturing it
12/27/1989EP0347556A1 Drilling tool for manufacturing drilled holes with recesses
12/20/1989CN2049592U Shaper for forming concrete water drain pipe by internal vibration and core drawing down
12/13/1989CN2049182U Moving concrete drain-pipe moulders
12/07/1989DE3818064A1 Sealing on precast concrete compound units which can be plugged together
12/05/1989US4885018 Molding suspension of solids in dispersing agent while mold is rotated
11/1989
11/29/1989EP0343677A1 Sealing means between two interengaging concrete pre-casts
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