Patents
Patents for B28B 21 - Methods or machines specially adapted for the production of tubular articles (3,281)
02/1980
02/06/1980EP0007358A1 Method of moulding concrete
01/1980
01/22/1980US4184520 Manually formable stirrup mat reinforcement and pipe reinforcing method based thereon
01/22/1980CA1070136A1 Building element
01/15/1980US4183724 Conduit making apparatus
01/01/1980US4181484 Device for forming underground pipelines
12/1979
12/11/1979US4178338 Method of casting thin-walled, hollow concrete posts
10/1979
10/16/1979CA1064229A1 Anti-torque fabric for pipe reinforcing gage
08/1979
08/28/1979CA1061070A1 Formation of products from temporarily plastic materials
08/07/1979US4163640 Apparatus for extruding a honeycomb structural body
07/1979
07/31/1979US4162771 Rod tensioner
07/24/1979CA1058840A1 Clay centering device for a potter's wheel
06/1979
06/26/1979US4159361 Cold formable, reinforced panel structures and methods for producing them
06/12/1979CA1056178A1 Reinforced panel structures and methods for producing them
05/1979
05/29/1979CA1055230A1 Machine for making concrete pipes in upright position
05/22/1979CA1054781A1 Mould for making tapered concrete poles
05/08/1979US4153232 Apparatus for actuating inner and outer forms of a concrete pipe forming mold
04/1979
04/24/1979US4151246 Manufacture of short pipes
04/05/1979WO1979000167A1 Method of moulding concrete
03/1979
03/27/1979CA1051173A1 Pile extruder
02/1979
02/06/1979CA1047743A1 Method and apparatus for forming refractory tubing
01/1979
01/16/1979US4134568 Plural molds with common actuating means
01/16/1979US4134567 Apparatus for forming fans
01/16/1979CA1046244A1 Apparatus for tensioning reinforcements in the process of manufacturing concrete poles and the like
12/1978
12/26/1978US4131408 Machine for making dry cast concrete pipe
11/1978
11/07/1978CA1041740A1 Apparatus for automatically adjusting center-height of a mold
10/1978
10/31/1978US4123033 Apparatus for forming hollow cylindrical pipes of reinforced concrete
10/24/1978CA1040844A1 Method and apparatus for forming steps in manholes and the like
10/10/1978CA1039930A1 Apparatus and method for manufacturing branched earthware pipe fittings
10/03/1978US4118165 Packerhead pipe making machine
09/1978
09/12/1978US4113823 Centrifugal technique
08/1978
08/29/1978US4109635 Machine grooved joint on hollow concrete cylinders
08/15/1978US4106300 Method of making reinforced cast-in-place concrete pipe
07/1978
07/25/1978US4102972 Refractory pipe fittings and production thereof
07/18/1978US4101622 Method of casting beveled pipe
04/1978
04/18/1978US4084828 Bell-and-spigot concrete pipe joint with plastic liner ring
04/18/1978US4084782 Split mould for making tapered concrete poles
04/04/1978US4082120 Method of producing tubular lattice reinforcement for reinforced concrete tubular pipe having a socket at one end thereof
03/1978
03/21/1978US4080135 Apparatus for formation of products from temporarily plastic materials
03/21/1978US4079500 Method of making reinforced concrete pipe
03/07/1978US4077577 Non-stressed, high strength, cement-containing pipe and its production
02/1978
02/21/1978US4075272 Ladder rung implanter
01/1978
01/10/1978US4067679 Machine for making concrete pipes in upright position
12/1977
12/27/1977US4065533 Process for the continuous production of silicon rods or tubes by gaseous deposition into a flexible wound band
11/1977
11/15/1977US4058428 Pipe coating machine
10/1977
10/11/1977US4053134 Pipe mold having insert support means
10/11/1977US4052916 Process for making a die punch
09/1977
09/20/1977US4049022 Concrete pipes
09/13/1977US4047693 Supporting ring for use in the casting of concrete pipes
08/1977
08/30/1977US4045533 Molding portland cement and an expansion component selected from calcium sulfate, oxide, and aluminate; curing
08/23/1977US4044088 Stressed hollow concrete cylinders
08/23/1977US4043723 Conduit molding machine
08/16/1977US4042315 Apparatus for making concrete pipe
08/09/1977US4041195 Compression
08/09/1977US4041118 Vibration treatment of wire reinforced concrete pipe
08/02/1977US4039642 Method of making concrete pipe
08/02/1977US4039608 Method and means for creating perforated concrete casing
05/1977
05/17/1977US4024006 Urethane
05/17/1977US4023771 Means for engaging, lifting and transporting concrete pipe molds
04/1977
04/19/1977US4018251 Machine for making reinforcing baskets for steel concrete posts, masts, pipes and the like
01/1977
01/18/1977US4003545 Core means having a rubber liner
11/1976
11/30/1976US3994651 Apparatus for removing waste portions from hollow moulded articles
11/02/1976US3989431 Pile extruder
11/02/1976US3989221 Form structure for use in the making of columnar or the like concrete products
11/02/1976US3989177 Ladder rung implanter
11/02/1976US3989144 Apparatus for transferring a mold
10/1976
10/19/1976US3986822 Boron nitride crucible
09/1976
09/28/1976US3982565 Prestressed concrete pipe
08/1976
08/17/1976US3974615 Apparatus for forming steps in manholes and the like
08/10/1976US3973749 Hollow formwork elements for producing concrete structures
07/1976
07/13/1976USRE28902 Vibratory core for concrete pipe making machine
06/1976
06/22/1976US3964522 Bevel pipe winder
06/22/1976US3964521 Bevel pipe winding method and product
06/08/1976US3962391 Disc support structure and method of producing the same
05/1976
05/18/1976US3957409 Means for creating perforated concrete casing
04/1976
04/20/1976US3951578 Apparatus for automatically adjusting center-height of a mold and the like used for manufacturing concrete pipes
04/13/1976US3950465 Centrifugal casting, glass fibers
03/1976
03/23/1976US3945787 Cap rest assembly for packerhead/vibration system concrete pipe machine
03/23/1976US3945782 Concrete pipes
03/09/1976US3942936 Facing ring and pouring chute for vertically cast concrete pipe
03/02/1976US3941347 Composite concrete and steel pallet for forming one end of concrete pipe
02/1976
02/17/1976US3938685 Means for engaging, lifting and transporting concrete pipe molds
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