DD208828A1 - METHOD FOR DISCONNECTING PRECIOUS METAL PIECES WELDED ON SUPPORT PIECES - Google Patents

Abstract

Intended in particular for the separation of welded on Kontakttraegern precious metal contacts, as used in the Eletrotechnik beitspielsweise in relays or coordinate switches. The increasing scarcity of precious metals requires a comprehensive recovery of precious metal scrap. The aim is to simplify the recovery and processing at a reduced expenditure. Task should be achieved in a short time with low energy consumption. u. According to the invention, the separation is carried out by means of ultrasound, by means of which an ultrasound vibrating tool is forcefully brought to one of the two differently sized pieces (1; 29) and the individual pieces are directed onto a sieve by means of a catching device (4) through which the smaller precious metal contacts (2) fall into a collecting container (6).

Description

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Berlin, 16.8.1982 qu-kb 29170/441

Applicant Gerhard Hoffmann

Dr.-Ing. Harald W. Rod

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Process for separating precious metal pieces welded onto support pieces

Field of application of the invention

The invention relates to a method for separating noble metal pieces welded onto carrier pieces, in particular noble metal contacts welded onto contact carriers.

In electrical engineering, it is currently still common to use precious metal or Edelmetallegierungeh as welded contacts in contact elements, such as relay contacts or coordinate switch contacts. The increasing scarcity of precious metals increasingly requires the recovery of production waste as well as precious metal scrap from decommissioned equipment and plants.

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Characteristic of the known technical solutions

It has long been customary to cut off the precious metal contact bearing contact spring piece and melt the resulting spring material scrap with Edelmetallahteil and excrete the precious metal by separating melts. The less pure the scrap is, the greater the time and energy required for precious metal recovery and the greater the melt losses of precious metal.

It is also common to shear the precious metal pieces from the support pieces by means of pneumatic-mechanical devices. However, a thin Ede 1 metal layer always remains on the carrier piece. In this way, on the one hand precious metal scrap and on the other hand spring material scrap is obtained with a component of precious metal. Similar to the previous solution, the effort and the losses are still considerable * On the other hand, a method for removing chips or burrs from a machined workpiece known (DE-OS 3,026,510, B 08 - 3/12), in which the workpiece is clamped between two clamping elements and are given to one of the clamping elements ultrasonic vibrations, so that the workpiece vibrates with the ultrasound. In this way, however, only relatively loosely adhering parts of the same material are separated ·

Zie1 of the invention

A simplification of precious metal scrap extraction and processing as well as a substantial reduction of the required effort are sought.

Explanation of the essence of the invention

The invention is based on the object, a method

3 - 4. ~ i

for the separation of welded on -Trägerstücken precious metal tue ken to develop in which in a short time with little energy and loss as possible on the one hand pure precious metal scrap and on the other hand pure spring material scrap or carrier material scrap is obtained.

According to the invention, this object is achieved in that the separation is carried out by ultrasound by an ultrasonic vibrating tool is frictionally brought to one of the two different sized pieces, either to the larger contact carrier or to the smaller Edelnietallkontakt and directed the individual pieces by means of a safety gear on a sieve are, by the precious metal contacts fall into a collection container, while the larger contact carrier remain on the screen. Be the solution of the invention, the previously unconsidered situation is exploited that the welded joint between precious metal contact and contact carrier has a notch stress, which with ultrasonic action good separation is possible · It follows that the ultrasound must be initiated in the vicinity of the weld.

The ultrasound is expediently introduced as a longitudinal wave having a vibration amplitude of 20 to 100 μm and a frequency of 10 to 40 kHz. \ 'As a safety gear is advantageously a usual acoustic enclosure used. i The exposure times are only fractions and the energy requirement is negligible compared to the described methods. ^All it takes is an ultrasonic device with a capacity of 400 ^1Λ 'as used for plastic ^welding .

embodiment

The invention is based on an embodiment

from the beginning of seconds

be explained in more detail. In the accompanying drawing, a device for separating welded on Tragerstücken Ede! Meta list üc loan is shown schematically. A contact carrier 1 with a welded Edelmetallkpntakt 2 is non-positively on an ultrasonic device 3 by the contact carrier between an ultrasonic vibrating tool or a sonotrode 31 and a support or anvil 34 is clamped · The clamping pressure is supplied by a press 33, which via an ultrasonic transducer 32nd on the sonotrode 31 presses. The device area sonotrode 31 to anvil 34 is surrounded by a displaceable or disclosed catching device 4, which terminates flush with a sieve 5, under which a collecting container 6 is arranged. · When the ultrasound device 3 is put into operation, the ultrasound from the sonotrode 31 acts directly on the contact carrier 1 and via this indirectly on the precious metal contact 2 a. Due to the high acceleration forces and taking advantage of the notch stresses of the welds the precious metal contact 2 is torn off, jumps against the safety gear 4 and falls from this through the wire 5 into the collecting 6. The Kontakträger .1 is done before inserting a new contact carrier in a separate container or can remain on dam sieve.

As experiments have shown, an anvil 34 may be dispensed with, and it is already sufficient if the contact carrier 1 is held at low pressure against the vibrating sonotrode 31.

Claims (3)

- 5 - fc ... T claim for invention 1 «method for separating precious metal pieces welded onto carrier pieces, in particular of noble metal contacts welded onto contact carriers, characterized in that the separation is effected by means of ultrasound, by applying an ultrasonic oscillating tool (31) to one of the two differently sized pieces of contact carrier (1) or noble metal contact (2) is frictionally introduced and that the individual pieces (1, 2) by means of
a safety device (4) are directed onto a sieve (5) through which the smaller precious metal contacts (2) in a
Collecting container (6) are passed while the larger contact carrier on the sieve (5) remain » 2, method according to item 1, characterized in that the ultrasound is introduced as a longitudinal wave having a vibration amplitude of 20 to 100, and at a frequency of 10 to 40 kHz. 3. The method according to item 1, characterized in that the catching device (4) is an otherwise conventional soundproofing hood is used. For this 1 page drawing