GB2031023A - Device for Use in Electroplating or Chemically Treating Small Parts in Bulk - Google Patents

Abstract

A containing device for facilitating handling of small parts in bulk during electroplating or chemical treatment having a perforated drum 3 for containing the parts 7, which drum is rotatable about its horizontal axis on bearings 9 of diameter nearly the same as that of the drum. A perforated tube 17 for introducing rinsing water or treatment fluids passes between the bearings inside the drum near the top. An open tank 19 connected to the tube or a pressure-tight coupling is provided for feeding liquid to the tube. Drying air can also be passed into the tube. Electrical connections 23 to the parts 7 for electroplating can also be passed through the bearings and be arranged to enter the parts from above. <IMAGE>

Description

SPECIFICATION Device for Use in Electroplating and/or Chemically Treating a Pourable Mass of Parts The invention relates to devices for use in electroplating and/or for chemically treating a pourable mass of parts. It is often required to electroplate or chemically treat small parts in bulk and a mass of such small parts can be usually poured like a liquid into a container for handling; such parts are referred to herein as pourable. The devices with which the invention is concerned are, for example, drums or bells intended to receive the parts being treated, and arranged to rotate about their longitudinal axes or execute a backward and forward movement during the treatment.

The treating of the parts normally requires several processing steps in baths of active liquids, that isto say, in solutions which help to alter the surface of the material being treated. For this purpose the receptacles with the parts to be treated are introduced in succession into the active baths.

Between the active baths it is necessary to have rinsing operations in order to remove traces of the previous active component before the next processing step.

This rinsing operation is usually performed by immersion into water-filled containers. This method requires a considerable consumption of rinsing water since the entire container has to be filled with water, and to achieve an adequate dilution of the traces of the active constituents adhering to the parts being treated it is necessary to change the contents of the rinsing container frequently. A large volume of discharged rinsing water containing a relatively small amount of impurities has therefore to be disposed of. In the treatment of waste water, however, it is desirable for small amounts of heavily contaminated water to be processed. A reduction in the amount of rinsing water can be achieved if several rinsing solutions are arranged one after the other in cascade, but the effect achieved thereby is still unsatisfactory.

There have been proposals to use a spray rinsing process instead of the immersion rinsing process, for example, by passing rinsing water through the bearing of an electroplating drum into the interior of the drum to rinse the parts being treated. The distribution of the rinsing water is effected in this case through a tube arranged centrally along the axis of rotation. However, it is a disadvantage that this tube is located amongst the parts being treated, or close above it, and several revolutions of the drum are necessary for all of the parts to be completely rinsed. Although, in this spray rinsing operation, less rinsing water is required than in the immersion rinsing operation, for the reason mentioned the consumption of water is still relatively high.

It has also been proposed that a rinsing or treating medium is sprayed through separate openings in the jacket of the drum into the interior of the drum. The liquid is admitted when the openings mentioned lie opposite stationary pressure elements arranged to provide a satisfactory sealed coupling to the openings. For this solution to the problem, relatively moving components are required which therefore are exposed to wear and the parts being treated can only be sprayed when the drum body is in certain positions. It is difficult to distribute the liquid evenly because admittance is effected via only a few openings. For these reasons the consumption of water for the rinsing process is greater than when the water can be sprayed uniformly over the complete mass of parts in the drum as the drum rotates.

It is an object of the invention to reduce further the amount of water required to rinse small parts that are treated in drums and bells, and thereby to improve the rinsing action.

According to the present invention there is provided a device for use in electroplating and/or chemically treating a pourable mass of parts including a container for a mass of parts and an arrangement for rinsing or treating liquid into the container, wherein the arrangement for introducing liquid into the container comprises at least one tube having a plurality of outlet orifices, which tube is so arranged that in use the liquid falls from the outlet orifices downwards on to a mass of parts in the container.

The container may be provided with bearings on which it is rotated, the diameter of the bearing journal being enlarged to such an extent that it is almost the same as the inner diameter or the inner width of the container, and the tube for admitting the liquid passed through the journal near its periphery.

The tube for admitting the liquid may extend over the entire length of the container which may be a drum and may have over its entire length orifices for the discharge of liquid. The orifices in the tube for admitting the liquid may be so disposed that liquid from the orifices even impinges on the inner wall of the container.

The liquid to be admitted may be fed into and/or stored in an open tank arranged on a support frame for the container from which tank the liquid flows to the introducing arrangement under gravity. Alternatively, a pressure-tight connection from a stationary reservoir to the tube may be produced by way of a coupling during or after the positioning of the container for a particular stage in a process.

Instead of liquid, hot air for the purpose of drying the parts being treated may be fed into the container.

In order that the invention may be fully understood and readily carried into effect an embodiment will now be described in detail with reference to the single figure of the accompanying drawing, which shows a longitudinal section through an electroplating drum.

In the drawing, a drum consists of a curved perforated jacket wall 2 and the two end walls 3 and 4. The iacket of the drum has an opening that may be closed by a lid 5. The parts being treated are introduced or emptied through the opening 6.

The end walls 3 and 4 of the drum have central bores 8 of which the diameter is almost as large as the inner diameter of the drum, and these bores provide bearings 9 on which the drum can rotate.

The drum 1 is held on the support arms 10 by way of the bearing journals 11. The support arms 10 are secured to a support frame 12 on which is mounted a drive motor 1 3 for rotating the drum.

The drive to the drum is effected via gear wheels 14 and 15 to the end face 3 of the drum which is also in the form of a gear wheel. Through the support arms 10 and the bearing journals 11 there are provided at the greatest possible distance from the axis of rotation of the drum whilst being within the bearings, bores 1 that accommodate a tube 1 7 for admitting a liquid.

This tube 1 7 extends over the entire length of the drum 1 and is also provided over its entire length with orifices in the form of bores 1 8 for the discharge of liquid. On one end of the two support arms 10 there is welded an open tank 1 9 that is in communication with the tube 1 7. When the drum assembly 20, which is movable, is positioned by a transport arrangement (not shown), for example, at a rinsing station, water runs from a stationary supply tube 21 into the tank 1 9 and then flows from there under the influence of gravity, as a result of the difference in levels, into the tube 1 7 from whence it emerges through the bores 1 8 and rinses the parts being treated.

A fixed connection between the drum assembly 20 and the supply tube for the liquid is not required in this embodiment of the invention.

The exact amount of water needed for the rinsing operation can be admitted into the tank 1 9 under the control of a magnetically operated valve 22 which is opened by a control apparatus, not shown, for a certain period of time only, after the drum assembly 20 has been positioned at the rinsing station.

The parts may also be electroplated within the device by immersing the container in an electrolyte at an electroplating station. The electroplating current to the parts being treated 7 may also be passed to theeparts through the bearing journal 11 by means of a cable 23. As the bearing journal 11 has a large diameter, the cable 23 can be passed through it at a point which lies above the parts being treated and the connection to the parts is made by a conductor extending downwards into the mass of parts in the container.

With conventional drums, the introduction of the cable carrying the electroplating current is effected through a central bore in a substantially smaller bearing journal. As a result, the point at which the cable passes into the mass of parts is generally inside the mass of parts being treated, so that as the drum rotates the cable is put under considerable stress by the circulating motion of the mass of parts being treated around a central axis.

It is also possible to blow hot air, instead of passing a liquid, into the interior of the drum through the tube 17 to dry the parts 7 when treatment is complete.

In an alternative embodiment, instead of providing a tank on the support arms as described above, means are provided to connect the tube 1 7 via a pressure-tight coupling to a liquid or air supply, which coupling is made when the device enters or has entered a treatment station.

Claims (8)

Claims

1. A device for use in electroplating and/or chemically treating a pourable mass of parts including a container for a mass of parts and an arrangement for rinsing or treating liquid into the container, wherein the arrangement for introducing liquid into the container comprises at least one tube having a plurality of outlet orifices, which tube is so arranged that in use the liquid falls from the outlet orifices downwards on to a mass of parts in the container.

2. A device according to claim 1, wherein the container is a drum with its axis substantially horizontal and mounted on bearings to be rotated about its axis and the diameter of the bearing journals is enlarged to such an extent that it is almost the same as the inner diameter or the inner width of the drum, and the tube for introducing the liquid is passed through the journal near its periphery.

3. A device according to claim 2, wherein the tube for introducing the liquid extends over the entire length of the drum and has distributed over its entire length the orifices for the discharge of liquid.

4. A device according to claim 1, 2 or 3, wherein the outlet orifices in the tube for introducing the liquid are so disposed that liquid from the orifices impinges directly on the inner wall of the container.

5. A device according to claim 1, 2, 3 or 4, wherein the liquid to be introduced is fed into and or stored in an open tank mounted on a support frame of the container, from which tank the liquid flows under gravity into the arrangement for introducing liquid into the container.

6. A device according to any of claims 1 to 4, including coupling means on the arrangement introducing liquid into the container by means of which, during or after positioning of the device at a treatment station, a pressure-tight connection to a stationary reservoir of liquid is produced.

7. A device according to any of claims 1 to 4 and 6, wherein means is provided so that instead of liquid, hot air is fed into the container for the purpose of drying a mass of parts therein.

8. A device for use in electroplating and/or chemical treatment of a pourable mass of parts, substantially as described herein with reference to the singie figure of the accompanying drawing, or modified as described herein.