DE1236475B - Holder for bars to be melted into zones - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

PATENT LETTERING

Int. Cl .:

Number:

File number:

Registration date: "

BOId

BOIj
German class: 12 c - 2

L38930IVc / 12c

May 8, 1961

March 16, 1967

September 21, 1967

Display day:

Issue date:

Pateritschrift agrees with the exposition

In the case of crucible-free zone melting, a rod is passed vertically through a fixed high-frequency coil out, in the area of which the liquid zone is formed. One also has to get a high level of evenness to achieve the growth process, the two solid parts of the rod, between which is the liquid Zone is located, can rotate against each other about their common axis, usually in such a way that the melting point Part was stationary while the growing part rotated.

The initiation of the process both with regard to translational movements of the rod parts as well their rotational movement presupposes that the liquid zone is fully developed, that is, that there are no bridges consist of solid material between the two rod parts more. It now requires increased attention of the operating personnel, pulling or rotating after switching on the heat source to be initiated only when the formation of the liquid zone is complete.

In this context, it is already known to have at least one of the two holders for the rod ends to be provided with one or more electrical contacts and between the holder and the fixed rod part and / or axially between the holder of the rod and its holder on the device frame to pretend so much play that the electrical contact or contacts are opened or closed be able.

At the moment when the melting zone goes through the entire cross-section of the rod, the contact-carrying ones approach Divide each other, because the rod parts are no longer firmly connected to each other. The closing ones Contacts then operate the motors for the rotation or translation of the rod parts.

In Fig. 1 is a partially schematic representation such a known device is shown. With 1 is the body to be treated, z. B. a silicon rod. designated. For the sake of clarity, it is shown in a significantly abbreviated form. Body 1 is on both Ends by means of a pin 2 and 3 guided through holes in the recesses of two quartz holders 4 and 5 attached. The lower quartz holder 5 is connected in the same way to a rotatable axis 6, while the upper quartz holder 4 is connected to the axis 7 via a pin, however, this pin 8 in turn can slide in a slot or slot pair 9 of limited length. the Axis 7 forms the holder of the clamping means 4 and the pin 8 forms the one firmly connected to the holder Part of the contact, while a contact tongue 10, which is provided on the quartz holder 4

Holder for rods to be melted into zones

Patented for:

Licentia Patent-Verwaltungs-G. m. b. H.,

Frankfurt / M., Theodor-Stern-Kai 1

Named as inventor:
Johannes Wulf, Rüthen / Möhne

represents the other part of the contact firmly connected to the clamping means 4. The two

^X 5 axes 6 and 7 are arranged to be axially displaceable both individually and together. Instead of the contact tongue 10, the delimitation of the slot at its end can also be designed as part of the contact means.

Since the pan-free zone pulling is advantageously carried out in a recipient, in which aggregates are often added for the crystal to be pulled are introduced in vapor form and also the vapor of the crystal material contains, and because some of these additives can also have a corrosive effect, there is Danger that the contact surfaces are vaporized with foreign substances and / or corrode, whereby the Making contact becomes imprecise.

It is already known to design devices for crucible-free zone drawing in such a way that parts of the Clamping means and parts of its holder so fit over one another that they form a closed Form a cavity in the interior of which the contact or contacts are located. This causes the Switching processes run more precisely.

^ The overlapping parts of the clamping device and its holder are preferably designed in the form of hollow circular cylinders, the outer diameter of the one hollow circular cylinder is at least approximately the same as the inner diameter of the other Hollow circular cylinder. The arrangement is expediently designed so that in the adjacent Walls of the overlapping hollow cylinder parts in one wall at least one slot and on the other wall there is at least one pin engaging in this slot for each slot. It is through it between clamping means and bracket a limited by the length of the slot clearance for a mutual displacement of the two parts created in the axial direction.

Along the axis of the upper hollow part (holder) and isolated from it is a rod-shaped elec-

709 676/34

Trode with a contact core, which has a contact plate at the lower end, is inserted into the cavity. Contact plate and an underlying one on the inner bottom of the lower hollow part or clamping means centrally arranged tabular elevations form the contact pair of the electrical contact device.

Since now the distance between the contacts and the available distance when lifting and lowering the crystal Stroke are not always the same, it can happen that switching positions arise in which through Leakage currents simulate a contact closure that does not yet exist or no longer exists.

This disadvantage arises in the case of a holder for rods to be fused into zones, consisting of two interlocking sliding hollow parts, the movement of which is limited by a slot and a pin and the one when pushing together or apart, closing electrical contact between a through the one part insulated in a cavity and the opposite other electrode Actuate part, according to the invention thereby prevented that around the contact plate of the electrode Ring magnet is arranged.

With such a device it is possible that the relative movement of the clamping means against his Bracket over part of the way within the scope of the closing or opening of the contacts can be accelerated or decelerated. The acceleration refers to the closing and the delay - through magnetic adhesion - on the opening of the contacts. In this way will ensures that a clear signal is always given by opening and closing the contacts that cannot be falsified by leakage currents.

In order to avoid unnecessary effort, it is advisable to use permanent magnetic components.

In particular, the device is according to the invention designed so that the ring magnet is displaceable along the electrode and rests on a spring.

You can get by with smaller magnets of lesser strength if you have to accelerate the magnet Keeps mass small. This can be achieved by moving one of the magnetic components towards the relative movement along the clamping means or the holder is movable. then you can keep its dimensions small and achieve the further advantage that the closing time of the contact becomes small. In this embodiment it is also possible that the magnetic component during the opening movement initially a spring is tensioned, which counteracts the magnetic force of attraction when it is further opened accelerates the movement of the contact parts away from each other.

F i g. 2 shows, in a partially schematic representation, an exemplary embodiment of the subject matter of the invention. With 11 the clamping means for the crystal is designated, with 12 its holder. In the holder 12, two slots 13 and 14 are provided in which two cams (pins) 15 and 16 slide on the Clamping means are attached. The holder 12 is pierced and leads in the bore 17 at 18 isolated performed contact core 19. About the contact core 19, which at its lower end with a plate-shaped contact 20 is provided, a ring magnet 21 slides, which is held by a spring 22 is that the magnet lower surface 23 and the surface 24 of the contact plate are at the same height.

If the clamping means 11 is now against its holding 12 moves, the surface 25 of the clamping means 11 comes into the field area of the ring magnet 21, which suddenly attracts and so the electrical contact between the contact core 19 and the clamping means closes. So a clear signal is given that z. B. the beginning of the melting process for Can trigger generation of the liquid zone.

Now falls z. B. after complete melting at its lower end of the crystal with its clamping means 11 downwards, the magnet 21 is pulled downwards with it until the Plate 20 on the contact core 19 prevents it from sliding on. The magnet 21 is thereby of the Clamping means 11 separated and by the tensioned spring 22 when moving apart in its rest position brought. The pulling process can then be initiated by the signal that is generated when the contact is opened will.

It is particularly advantageous if the contact is made directly through the placement of the lower surfaces of the electrode plate and the ring magnet is closed.

Claims (2)

Patent claims: 1. Holder for rods to be melted into zones, consisting of two hollow ones that slide into one another Parts whose movement is limited by a slot and a pin and the one at Pushing together or apart closing electrical contact between a through the one part insulated in a cavity and the opposite electrode actuate other part, characterized that a ring magnet (21) is arranged around the contact plate (20) of the electrode (19). 2. Apparatus according to claim 1, characterized in that a permanent magnet is used is. 3. Apparatus according to claim 1 and 2, characterized in that the ring magnet (21) is displaceable along the electrode (19) and rests on a spring (22). 4. Apparatus according to claim 3, characterized in that the ring magnet (21) when moving the spring in the sense of the contact opening (22) claimed. 5. Device according to claims 1 to 4, characterized in that the contact is made takes place directly on the lower end face (23) of the ring magnet (21). - Legacy Patents Considered:
German Patent No. 1 209 550. 1 sheet of drawings 709 519/353 3.67 Bundesdruckerei Berlin