A method of producing a cylindrical insulator for a spark plug includes a molding step of forming ceramic powder filled in a cavity defined by a mold and a molding pin into a compact. In a first removal step of removing the compact from the mold, the compact has at least one protrusion formed in at least one recess of the molding pin formed in an outer cylindrical surface of the molding pin, and the at least one protrusion is locked in the at least one recess, thereby allowing the compact to be removed with the molding pin from the mold. In a second removal step of removing the molding pin from the compact, the molding pin is turned or rotated in the circumferential direction about the compact, causing the at least one recess to cut the at least one protrusion from the compact, and thereafter the molding pin is removed from the compact.

A core puller device for a block machine, a block machine with such a device as well as a method for the preparation of shaped stones in which at least one core puller arranged on the sliding facility of the core puller device is temporarily inserted into a stone mould of the block machine and retracted after a packing operation in the block machine are provided. Here, the core puller device is constructed or the method is configured such that the operative connection between the at least one core puller and the sliding facility of the core puller device is temporarily neutralized.

A mold assembly and method for molding two concrete blocks in face-to-face non-contacting relationship forms blocks having smooth front faces. The mold assembly includes a mold box having two mold cavities configured to form two blocks in face-to-face non-contacting relationship. A common partition plate separates the two mold cavities and opposite sides of the partition plate form the smooth front faces of the blocks. The two mold cavities are each configured to form a block having a raised front face with a beveled edge around its entire perimeter and a border around the entire perimeter of the beveled edge. The portions of the border at the top and the sides of the raised front face are curved and the portion of the border at the bottom of the raised front face is straight. A core bar is slidably inserted into the mold box beneath the bottom of the partition plate, and opposite sides of the core bar extend into and form the front bottom portions of the mold cavities.

A mold assembly and method for molding two concrete blocks in face-to-face non-contacting relationship forms blocks having smooth front faces. The mold assembly includes a mold box having two mold cavities configured to form two blocks in face-to-face non-contacting relationship. A common partition plate separates the two mold cavities and opposite sides of the partition plate form the smooth front faces of the blocks. The two mold cavities are each configured to form a block having a raised front face with a beveled edge around its entire perimeter and a border around the entire perimeter of the beveled edge. The portions of the border at the top and the sides of the raised front face are curved and the portion of the border at the bottom of the raised front face is straight. A core bar is slidably inserted into the mold box beneath the bottom of the partition plate, and opposite sides of the core bar extend into and form the front bottom portions of the mold cavities.

A method for manufacturing a curable light-conducting body (21) in a casting method, in particular for the manufacture of light-conducting bodies (21) of a curable concrete material (36, 56), wherein a light-conducting mat (1) is embedded in a curable casting material (36, 56), and a casting mold (27) with a recessed mold cavity (18) open at the top is filled with the not-yet-cured casting material (36, 56), wherein, in a first method step, a plurality of molding punches (32) moveably arranged in the mold cavity (18) of the casting mold (27) are moved to at least the plane of the upper edge (43) of the mold cavity (18), 1. in a second method step, the space between the molding punches (32) in the mold cavity (18) is filled with a curable casting material (36), 2. in a fifth method step, the light-conducting mat (1) to be embedded in the casting material (36, 56) is placed on the end sides (61) of the molding punches (32) raised in the mold cavity (18), 3. and that, in a sixth method step, the light-conducting mat (1) is pressed into the casting material (36, 56) wherein, with the pressing movement of the light-conducting mat (1) into the casting material (36, 56), the molding punches (32) are approximately synchronously moved downwards out of the bottom surface of the mold cavity (18).

A method of producing a cylindrical insulator for a spark plug includes a molding step of forming ceramic powder filled in a cavity defined by a mold and a molding pin into a compact. In a first removal step of removing the compact from the mold, the compact has at least one protrusion formed in at least one recess of the molding pin formed in an outer cylindrical surface of the molding pin, and the at least one protrusion is locked in the at least one recess, thereby allowing the compact to be removed with the molding pin from the mold. In a second removal step of removing the molding pin from the compact, the molding pin is turned or rotated in the circumferential direction about the compact, causing the at least one recess to cut the at least one protrusion from the compact, and thereafter the molding pin is removed from the compact.

A method for manufacturing a curable light-conducting body (21) in a casting method, in particular for the manufacture of light-conducting bodies (21) of a curable concrete material (36, 56), wherein a light-conducting mat (1) is embedded in a curable casting material (36, 56), and a casting mold (27) with a recessed mold cavity (18) open at the top is filled with the not-yet-cured casting material (36, 56), wherein, in a first method step, a plurality of molding punches (32) moveably arranged in the mold cavity (18) of the casting mold (27) are moved to at least the plane of the upper edge (43) of the mold cavity (18), 1. in a second method step, the space between the molding punches (32) in the mold cavity (18) is filled with a curable casting material (36), 2. in a fifth method step, the light-conducting mat (1) to be embedded in the casting material (36, 56) is placed on the end sides (61) of the molding punches (32) raised in the mold cavity (18), 3. and that, in a sixth method step, the light-conducting mat (1) is pressed into the casting material (36, 56) wherein, with the pressing movement of the light-conducting mat (1) into the casting material (36, 56), the molding punches (32) are approximately synchronously moved downwards out of the bottom surface of the mold cavity (18).

A mold for manufacturing interlocking, dry-cast concrete retaining wall blocks in an upright orientation comprises a mold box comprising two side walls joined to end walls to define a mold cavity, a top face, and a substantially open bottom face. Partitions configured to define a space between adjacent blocks or a space between a block and a side of the mold box extend parallel to the side walls of the mold box substantially from the top face into the mold cavity, to form first transverse portions of the profile of the top and bottom surfaces the blocks which do not include any undercut portion that would impede removal of the mold box in a substantially vertical direction. At least one removable insert comprises insert members which, when positioned in the mold box beneath the partitions, form remaining transverse portions of the profile of the top and bottom surfaces, the remaining transverse portions including at least one undercut portion. The insert members, when in position in the mold box for casting, are substantially in lateral alignment with respective bottom surfaces of at least some of the partitions and can be inserted and retracted through openings in an end wall of the mold box.

A mold assembly and method for molding two concrete blocks in face-to-face non-contacting relationship forms blocks having smooth front faces. The mold assembly includes a mold box having two mold cavities configured to form two blocks in face-to-face non-contacting relationship. A common partition plate separates the two mold cavities and opposite sides of the partition plate form the smooth front faces of the blocks. The two mold cavities are each configured to form a block having a raised front face with a beveled edge around its entire perimeter and a border around the entire perimeter of the beveled edge. The portions of the border at the top and the sides of the raised front face are curved and the portion of the border at the bottom of the raised front face is straight. A core bar is slidably inserted into the mold box beneath the bottom of the partition plate, and opposite sides of the core bar extend into and form the front bottom portions of the mold cavities.

A core puller device for a block machine, a block machine with such a device as well as a method for the preparation of shaped stones in which at least one core puller arranged on the sliding facility of the core puller device is temporarily inserted into a stone mould of the block machine and retracted after a packing operation in the block machine are provided. Here, the core puller device is constructed or the method is configured such that the operative connection between the at least one core puller and the sliding facility of the core puller device is temporarily neutralized.