Abstract: A lock valve disposed between a pulling pot and a lock chamber is opened at the start of the pulling process and thereby uncovers a lock entrance for the crystal that is to be pulled, and together with a gasket closes the lock entrance after the end of the pulling process and thereby hermetically separates the pulling pot from the lock chamber. The gasket (9) is protected during the pulling of the crystal by a guard (15, 16) against the thermal radiation of the hot crystal.

Abstract: A method and an apparatus are proposed for pulling crystals from the melt. The recharging of the melt (4) is performed such that the crucible (3) is raised and lowered with respect to the crystal pulling system while keeping the position of the melt surface (25) constant with respect to the crystal pulling system.

Abstract: A pulling shaft carries a seed crystal holder and moves it vertically to pull a crystal upward from a melt in a crucible. The pulling shaft is rotated by a drive to cause the crystal to rotate while being pulled. A slippage device is provided to permit a difference between rotational speeds of the pulling shaft and the seed crystal. The slippage device may be incorporated in a crystal holder having an inner holder fixed to the seed crystal, an outer holder fixed to the shaft, and a friction bearing therebetween which prevents undue torsional stress from being transmitted to the crystal.

Abstract: Apparatus includes a crucible, a cover with an opening over the crucible, a pulling element for pulling monocrystal from melt in the crucible, and first and second heating elements. The first element is a substantially flat radiaent heat source below the crucible and the second element is a pot shaped, comprising a flat heat source above the melt and a cylindrical heat source about the crucible. A ring having holes therethrough is inserted in the crucible to quiet the melt, a filler funnel emptying material to be molten outside of the ring while the monocrystal is pulled from inside the ring.

Abstract: In an apparatus for the continuous feeding of material to a melting crucible in the pulling of monocrystals in a vacuum tank, a first container (3) is provided which is provided with an internal lining (4) adapted to the container shape and having a funnel-shaped section (4') and a cylindrical outlet (4"') adjoining the latter, the outlet (4"') being displaceable through a lock valve (10) into the connecting pipe (11) of a second container (12) which in turn, through an outlet tube (18) with elbow (19) brought through the wall of the vacuum tank, leads into the area above the melting crucible. The two containers (3, 12) are for that purpose coupled with the hydraulic cylinder (28) of a linear actuator by which the distance between the two containers (3, 12) can be varied.

Abstract: A crystal holder for apparatus for pulling a crystal from a melt in a crucible with a reelable pulling member fastened to the crystal holder has thermal insulation between the fastener for the reelable pulling member and a clamping device for the crystal. The thermal insulation preferably comprises a tie rod between sections of the crystal holder, the tie rod having a cross section sufficiently smaller than the sections for insulation therebetween, an insulating spacer about the tie rod, and radiation shields about the spacer, the radiation shields having diameters no longer than the sections of the crystal holder. Foil insulation spaced about the crystal holder at the crystal clamp may also be provided. The insulation appreciably extends the life of the pulling member.

Abstract: Apparatus for producing monocrystals by potless zone melting, in which the monocrystal, setting out from a seed crystal, passes through a neck and a transitional zone into the main part of the monocrystal. A chamber is provided for the formation of a vacuum or a protective gas atmosphere plus a heating device for the production of the melting heat, driving means for the mechanical movements necessary for the crystal formation, a mounting for the seed crystal, and a supporting device which is applicable to the monocrystal beyond the neck, and a plurality of gripping bodies distributed about the circumference and applicable to the monocrystal radially on its substantially cylindrical surface the gripping bodies are disposed such that they first perform a radial approach to the monocrystal until a virtually force-free contact is made therewith, adapting themselves to the surface geometry and position of the monocrystal, whereupon the gripping force is increased and the gripping bodies are locked.

Abstract: Apparatus for producing monocrystals by potless zone melting, in which the monocrystal, setting out from a seed crystal, passes through a neck and a transitional zone into the main part of the monocrystal. A chamber is provided for the formation of a vacuum or a protective gas atmosphere plus a heating device for the production of the melting heat, driving means for the mechanical movements necessary for the crystal formation, a mounting for the seed crystal, and a supporting device which is applicable to the monocrystal beyond the neck, and a plurality of gripping bodies distributed about the circumference and applicable to the monocrystal radially on its substantially cylindrical surface the gripping bodies are disposed such that they first perform a radial approach to the monocrystal until a virtually force-free contact is made therewith, adapting themselves to the surface geometry and position of the monocrystal, whereupon the gripping force is increased and the gripping bodies are locked.