FR2823769A1 - Apparatus for positioning of workpieces in electrolytic coating bath has adjustment device connecting positioning bar to actuation beam so that movement of latter changes orientation of workpiece - Google Patents

Abstract

Apparatus for positioning of workpieces (P) mounted on a rigid body in an electrolytic bath includes an adjustment device (16, 17) that connects a positioning bar (21, 21') to an actuation beam (15) such that movement of the actuation beam changes the orientation of the workpieces with respect to a working anode. In an apparatus for positioning of workpieces (P) mounted on a rigid body (10) in an electrolytic bath, with respect to a working anode, the rigid body (10) includes: (a) an actuation beam (15) arranged slidingly along a vertical axis (x-x); (b) at least one rotary positioning bar (21, 21') supporting a series of fixing elements (22) for the workpiece; and (c) an adjustment device (16, 17) connecting the positioning bar (21, 21') to the actuation beam (15) such that movement of the actuation beam (15) changes the orientation of the workpieces (P) with respect to the working anode.

Description

tungsten from solidification is between 3 and 4.5 µm.

  The present invention relates to a device for positioning with respect to at least one anode for working parts to be coated, in particular parts having concave zones or large cavities.

  aunts, in electrolytic treatment tanks.

  s Coating of metallic parts by corresponding electrolysis

  is based on an industrial process well known to specialists.

  During the implementation of this process, the parts to be coated which generally act as cathodes are immersed in baths

  electrolysis containing fixed anodes.

  o The installations intended for this implementation on an industrial scale frequently include mobile overhead traveling cranes moving back and forth above treatment tanks filled with baths

  which are aligned one after the other.

  These overhead traveling cranes are fitted with hoists on which rigid frames carrying parts to be coated can be hung so as to allow the rigid frames to be successively placed in the various treatment tanks and consequently to immerse the parts to be coated in the different baths. of electrolysis and extract it as you go from

moving the crane.

  o Such an installation is schematically represented on

Figure 1.

  According to this figure, the traveling crane 1 moves back and forth in the double arrow A above a series of treatment tanks C 1, C2, C3, C4, etc., each containing a bath: 5 of electrolysis and is equipped with a hoist 2 at the end of which is hung

  a rigid frame 3 supporting a series of parts to be coated, not shown

  Tees. The hoist 2 makes it possible to vertically move the chassis 3 according to arrow B so as to place it successively in the tanks C1,

C2, C3, C4 ... and extract it.

  The parts to be coated are thus also successively immersed and extracted from the electrolytic treatment baths contained

in tanks C1, C2, C3, C4, ...

  In the particular case of the treatment of parts having 3s of concave zones or large cavities (of the type of cups, tubes, etc.) the positioning of these parts in the electrolysis baths with respect to the working anodes is of very particular importance. : indeed, poor positioning results in the appearance of "treatment shadow zones>, that is to say zones in which the thicknesses of the coating

are too weak.

  This is a serious disadvantage from an economic point of view since it often leads to problems of scrap parts or pollution of the treatment baths. However, up to now no device has been proposed for ensuring in all cases a satisfactory positioning with respect to the working anodes of the parts to be coated in treatment tanks by electrolytic means, and these are currently as a rule largely randomly positioned in electrolysis baths. FIGS. 2a, 2b and 2c illustrate this difficulty by representing three possibilities of orientation of a hollow part to be coated P with respect to a working anode 4 in an electrolytic cell in which the current lines within the bath of treatment are shown schematically by

horizontal arrows.

  According to FIG. 2a, the cavity of the part P is oriented towards the bottom of the treatment tank. In this position a large part of the periphery of the part P is not directly exposed to the current lines: this results in the formation of an air bubble b at the upper part of the cavity and the appearance of Treatment shadow areas has large on the face. According to FIG. 2b, the cavity of the part P is on the contrary

  oriented towards the top of the treatment tank.

  In this position, a large part of the periphery of the part P is again not directly exposed to the current lines, which also results in the appearance of areas of processing shadow a.

big surface.

  In addition, this orientation causes retention of the electrolysis bath at the lower part of the cavity of the part P. On the other hand, according to FIG. 2c, the cavity of the part P is oriented opposite the working anode 4 so that the parts of the periphery of this part which are not directly exposed to the current lines and consequently the surface of the shaded areas of treatment have been

minimized.

  Consequently, the parts to be coated P must in the same

  sure of the possible be oriented in this last position.

  The object of the present invention is to remedy the above-mentioned drawbacks by proposing a positioning device making it possible in all cases to guarantee optimum orientation of the

  parts to be coated with respect to at least one working anode.

  Such a device comprises a rigid frame which supports a series of parts to be coated and is intended to be mounted on a hoist per by placing it in a treatment tank and extracting it, and consequently immersing the parts to be coated in the electrolysis bath contained

in this tank.

  o According to the invention, this process is characterized in that the rigid chassis is equipped with: - a control beam mounted to slide along a vertical axis, - at least one positioning rod mounted to rotate around its longitudinal axis and carrying a series of fasteners for a respective piece to be coated, and - adjustment means connecting the positioning rod (s) to the control beam so that a translation of the latter drags one rotation of the positioning rod (s) and consequently a modification of the orientation of the parts to be coated with respect to

the working anode.

  According to the invention, the adjustment means preferably comprise a main adjustment bar secured to the or a po rod.

  position and directed essentially perpendicular to it.

  This main adjustment bar is articulated on the one hand on the control beam and on the other hand on a fixed part of the rigid frame around an articulation axis coinciding with the positioning rod. According to a preferred characteristic of the invention, the control beam o is equipped at its upper part with a nozzle forming a stop intended to come into abutment against the edge of a treatment tank. When the hoist lowers the chassis on which the parts to be coated are mounted towards a treatment tank containing an electrolysis bath, the control beam is integral with this chassis and is held in a lowered position relative to the latter until that the end-piece forming a stop strikes the edge of the tank and comes to bear

against it.

  From this moment the control beam can no longer continue its downward movement, joined to the chassis and therefore rises with respect to the latter considered to be fixed until it

  is placed at the bottom of the treatment tank.

  This movement of the control beam relative to the chassis causes the parts to be coated to pivot relative to the working anode, which makes it possible to orient them in an optimum position.

  conditioned by the initial settings of the device.

  Of course, this movement is reversed when the hoist is

  o reassemble the chassis out of the treatment tank.

  According to another particularly advantageous characteristic of the invention, the positioning device has several stages and the adjustment means comprise a first annex adjustment bar and, where appropriate, a series of annex adjustment bars mounted one after the other. and hinged on each other at their

respective ends.

  The first additional adjustment bar is articulated on the main adjustment bar at one of its ends and if necessary at

  a second adjuster bar at its opposite end.

  o According to the invention, each of the annex adjustment bars is equipped with a positioning rod directed essentially perpendicularly integrally thereto and carrying a series of fasteners for a respective piece to be coated, and is articulated on a fixed part of the rigid frame around an axis of articulation which coincides with the rod

s corresponding positioning.

  In view of this configuration, the abutment of the end-piece forming a stop against the edge of a treatment tank results in an upward movement of the control beam relative to the chassis considered to be fixed, and consequently a successive pivoting. of all the stages of the device, therefore of all the positioning rods; this results in a successive modification of the orientation of the series of parts to be coated respectively fixed on these rods relative to the working anode. According to another characteristic of the invention, the device 3s comprises a series of cams of different heights intended to be mounted on the edges of a treatment tank so as to vary

  the orientation of the parts to be coated with respect to the working anode.

  The presence of this cam allows to adjust the inclination of the parts to be coated according to the different baths in which

they are processed.

  The characteristics of the positioning device which is the subject of the invention will be described in more detail with reference to the attached sins in which: - Figure 1 is a schematic view of an industrial installation for processing parts to be coated in a series of electrolysis cells mounted one after the other, o - FIGS. 2a, 2b and 2c are diagrams illustrating the role played by the orientation of the parts to be coated in the electrolysis bath, Figure 3 is a schematic view of the device according to the invention, - s s s 4 a, 4 b and 4 c are s detail view s representing three po s if successive orientation abilities of a part to be coated in the device according to the invention, - Figure 5 is a diagram illustrating the influence of cams mounted on the

  edge of a treatment tank on the orientation of parts to be coated.

  Figure 3 shows a two-stage device.

  Of course, this is only an example of configuration which should in no way be considered as limiting the invention. According to Figure 3, the device is essentially constituted by a rigid frame 10 equipped at its upper part with a member

  attachment 11 allowing its attachment to a hoist.

  s In the example shown in Figure 3 the rigid chassis

  comprises two parallel fixed uprights 12, 122.

  The first of these uprights 12 carries a cross member 13 provided with a bore 14 in which a control beam 15 is mounted

  sliding along a vertical axis XX '.

  n / a The control beam 15 is equipped at its upper part with a stopper forming a stopper 6 arranged in projection which is shown

schematically in the figure.

  When the rigid frame 10 is freely attached to the end of a hoist, the end-piece forming a stop 6 comes to bear against the cross-member 13; the control beam 15 is then in a position

  low relative to the chassis 10, as shown in FIG. 3.

  When the hoist lowers the chassis 10 towards a treatment tank, the end piece forming a stop 6 will come to bear at a moment

against the edge of this tank.

  From this moment, the control beam 15 is deso lidarisce of the chassis 10 and moves upwards relative to the latter considered to be fixed according to arrow D, until it reaches the bottom.

of the tank.

  Furthermore, and as shown in FIG. 3, the device

  tif also has two articulated adjustment bars 16, 17.

  o The first of these adjustment bars or main adjustment bar 16, is articulated on the one hand on the control beam 15 at one of its ends or first end 16i, this around an axis 18 and other leaves on the second adjustment bar or annex adjustment bar 17 at the first end 17i thereof, by its second ex

  end 162, around an axis 19.

  The main adjustment bar 16 is also articulated at its middle part on the first fixed upright 12i of the rigid frame 10

around an axis of articulation 20.

  The main adjustment bar 16 is also equipped with its

  o middle part of a positioning rod 21 fixed securely essen-

  perpendicular to it and whose axis coincides with the axis

hinge 20.

  The positioning rod 21 is therefore movable in rotation

  according to the double arrow E around the axis of articulation 20.

  : 5 According to Figure 3, the annex adjustment bar 17 is articulated on the second fixed upright 122 of the rigid frame 10 around

  a hinge pin 20 'at its second end 172.

  The adjuster adjustment bar 17 is also equipped at the level of its second end 172 with a positioning rod 21 'fixed integrally essentially perpendicular thereto and whose axis

  coincides with the articulation axis 20 '.

  The positioning rod 21 'is therefore movable in rotation

  according to the double arrow E 'around the axis of articulation 20'.

  As shown more precisely in FIGS. 4a, 4b and 4c, the positioning rods 21, 21 ′ carry a series of fixing members 22 each allowing the attachment of a part to be coated P. According to FIG. 3, the movement towards the top of the control beam 15 according to arrow D causes the downward movement of the axis 19 according to arrow F and the rotation according to arrows E and E 'of the positioning rods 21, 21' and the fixing members 22 worn by them,

  so that the pieces P to be coated are successively oriented with respect to

  port to the working anodes positioned in the electrolytic cells in accordance with Figures 4a, 4b and 4c. According to Figure 5, the establishment on the edge of the tank

  treatment shown schematically by the axis Y-Y 'of cams 23, 23' of different heights

  allows modulating the inclination s of the part s P to be coated with respect to

at the working anodes.

Claims (4)

  1) Positioning device with respect to at least one anode for working parts to be coated, in particular parts having concave zones or large cavities, in electrolytic treatment tanks, device comprising a rigid chassis supporting a series of parts to be coated and intended to be mounted on a hoist, in particular on a hoist equipping an overhead crane movable in reciprocating movement above treatment vessels aligned one after the other so as to allow to place the chassis and to immerse the parts to be coated in a treatment tank and to extract them therefrom, characterized in that the rigid chassis (10) is equipped with: - a control beam (15) slidably mounted along a vertical axis (x-xl, - at least one positioning rod (21, 21l rotatably mounted about its longitudinal axis (20, 20l and carrying a series of fasteners (22) of a piece to be coated ir (P) respectively, and - adjustment means (16, 17) connecting the positioning rod (s) (21, 21 ') to the control beam (15) so that a translation of the latter causes a rotation of the positioning rod (s) (21, 2 ll and consequently a modification of the orientation of the parts to   coating (P) relative to the working anode.   2) Device according to claim 1, characterized in that the adjustment means comprise a main adjustment bar (16) so lidaire of the or of a positioning rod (21), directed essentially perpendicular thereto and articulated d 'on the one hand on the control beam (15) and on the other hand on a fixed part of the rigid frame (10) around a hinge pin (20) coinciding with the positioning rod ment (21).   3) Device according to any one of claims 1 and 2,   characterized in that the control beam (15) is equipped at its upper part with a stop forming end (6) intended to come into abutment against the edge of a tank treatment.   4) Device according to any one of claims 1 to 3,   ., characterized in that the adjustment means comprise a first additional adjustment bar (17) articulated on the main adjustment bar (16) and, where appropriate, a series of additional adjustment bars mounted one after the other ,   and hinged on each other at their respective ends, each   none of these additional adjustment bars (17) being equipped with a rod   position (21 ') directed essentially perpendicularly integral therewith and carrying a series of fixing members (22) o of a piece to be coated (P) respective and being articulated on a fixed part of the movable frame (10) around a hinge pin (20 ') coinciding with the   positioning rod (corresponding 213.    ) Device according to any one of claims 1 to 4,   characterized in that it includes a series of cams (23, 23 ') of different heights   to be mounted on the edges of a treatment tank so as to   put to vary the orientation of the parts to be coated (P) relative to the working anode.