US3873435A - Oscillating barrels including electrical contact means - Google Patents

Abstract

A galvanizing device comprising a plastic, pivotally mounted drum having longitudinal, perforated walls to hold workpieces, means for rocking the drum to a limited extent, a carrying frame in which the drum is pivoted, the transverse cross-section of the walls being partially heart-shaped, longitudinal strengthening bars attached to the walls and to the ends of the drum, the bars carrying partially exposed current-carrying contact rods, and connections from the rods to a low-voltage high current electric supply. The drum dips into a vat containing treatment liquid which penetrates the holes in the walls and contacts the workpieces in the drum.

Description

Ziebarth et al.

OSCILLATING BARRELS INCLUDING ELECTRICAL CONTACT MEANS Inventors: Paul Erich Ziebarth, Auf der Suelte 645, 481 l Hillegossen; Reinhold Ritter, Elsener Strasse, 4900 Herford-Elverdissen, both of Germany Filed: Apr. 4, 1973 Appl. No.: 347,890

Related US. Application Data Continuation-impart of Sen No. 145,254, May 20, 1971, Pat. No. 3,723,284.

US. Cl 204/222, 204/213, 259/75 Int. Cl C23b 5/78 Field of Search 204/213, 214, 222; 259/89 10/1962 Ncilson 204/213 10/1964 Belkc 204/213 Mar. 25, 1975 3,340,170 9/1967 Marulli et a1. 204/213 3,394,070 7/1968 Neilson 204/213 FOREIGN PATENTS OR APPLICATIONS 1,438,559 4/1965 France 204/213 Primary ExaminerHoward S. Williams Assistant Examiner-W. 1. Solomon Attorney, Agent, or Firm-Leonard H. King [57] ABSTRACT A galvanizing device comprising a plastic, pivotally mounted drum having longitudinal, perforated walls to hold workpieces, means for rocking the drum to a limited extent, a carrying frame in which the drum is pivoted, the transverse cross-section of the walls being partially heart-shaped, longitudinal strengthening bars attached to the walls and to the ends of the drum, the bars carrying partially exposed current-carrying contact rods, and connections from the rods to a lowvoltage high current electric supply. The drum dips into a vat containing treatment liquid which penetrates the holes in the walls and contacts the workpieces in the drum.

5 Claims, 8 Drawing Figures PATENTED HARZ 5 I975 sailings OSCILLATING BARRELS INCLUDING ELECTRICAL CONTACT MEANS This application is a continuation-in-part of copending application, Ser. No. 145,254, filed May 20, 1971, and now U.S. Pat. No. 3,723,284 granted Mar. 27, 1973.

The aforementioned abstract is neither intended todefine the invention of the application which, of course. is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.

The invention relates to a galvanizing device having a drum adaptd to receive the articles to be galvanically treated.

U.S. Pat. No. 3,058,902 discloses a rotary drum which has contact rods in the drum space which are secured to an end face of the drum and to a metallic contact disc incorporated in the end face of the drum. The contact disc is slipped over a bearing sleeve which is mounted so as to be rotatable on a bearing pin that is electrically connected to the current supply in order to provide a central current supply through the bearing of the drum. This method of current collecting is a disadvantage because of the line contact existing'during drum rotation; that is, bearing play occurs between the bearing axle and the bearing sleeve and produces a relatively bad current collection which requires a longer treatment period for the components and hence an increase in costs for the galvanizing. Moreover, the shape of the drum and the rotary motion of the drum frequently results in inadequate turning over of the articles to be galvanized, especially since the articles are moved in one direction. The contact dis'c moreover cannot be replaced when required without detaching the end face parts of the drum.

U.S. Pat. Nos. 2,830,946 and 2,479,323 disclose oscillating drums in which current is supplied to the articles being galvanized by means of cables projecting into or suspended in the interior of the drum having contact members at the end faces. The ends of the contact cables, remote from the interior of the drum, are located on contact discs provided with a central current supply passing through the bearing between the bearing axle and the bearing bore. Herein too there is an inferior current supply to the articles being galvanized and hence a longer galvanizing period required, which is uneconomical. In these patents the oscillating drum is provided with a base of W-shaped transverse cross-section. However, because of the straight surfaces of both channels of this W-shaped base the drum does not provide sufficient movement (revolution and intermixture) of the articles being galvanized.

The object of the invention is an improved galvanizing device with which satisfactory galvanizing may be obtained in a relatively short time. The drum, comprising this invention, is of simple structure, stable, has a long life, and is provided with a reliable current supply, permitting proper current collection. Moreover, the drum comprising this invention is formed as an oscillating drum and has a cross-section which ensures an improved intermixture of the articles to be galvanized.

The galvanizing drum in accordance with the invention is distinguished by a simple, stable structure and an The current supply is preferably not coupled to the drum mounting, but occurs at two contact members so as to be readily interchangeable at each end face of the drum. The contact rods leading into the drum interior are located so as to be readily interchanged. The contact members may be interchanged and/or replaced without dismounting them from the drum.

Moreover, the preferred heart shape or inverted heart shape of the drum cross-section ensures a better intermixing of the articles being galvanized, since in each of the two trough-like channels or grooves of the drum base a favorable rolling motion and intermixing of the individual parts occurs during the oscillation of the drum. The two base hollows ensure a substantially better intermixing of the parts to be galvanized than heretofore with known V-channels of a W-shaped oscillating drum base.

BRIEF DESCRIPTION OF THE DRAWING In the various figures of the drawing, like reference characters designate like parts.

In the drawing:

FIG. 1 is a perspective view of an electroplating device comprising this invention;

FIG. 2 is a transverse cross-section view through the pendulum drum shown in FIG. 1;

FIG. 3 is a longitudinal sectional view through the pendulum drum shown in FIG. 1;

FIG. 4 is a fragmentary sectional view taken at point A. in FIG. 3;

FIG. 5 is a fragmentary sectional view taken at point B in FIG. 3;

FIG. 6 is a fragmentary view, partially in section, taken at point C in FIG. 3;

FIG. 7 is an end elevational view of a pendulum drum in accordance with this invention; and

FIG. 8 'is an end elevational view of the index ring of FIG. 7 in an inverse pivotal position.

DESCRIPTION OF THE PREFERRED EMBODIMENT A plating device of the invention for the galvanic surface treatment of merchandise (shaped parts) possesses a pendulum drum 12, which is mounted so as to be pivotable to and fro in a carrying framelO, and defines openings 11 on the side of the casing for the passage of a medium, the drum being rotatably and de .are connected together by a common strengthening bar 19 which simultaneously forms av support 17 for a contact bar 18, which is partly enclosed therein, and is connected to a current supply. The individual wall parts 15 and 16 of the drum 12 are fastened by welding to the strengthening barsand by welding to end plates 20, which terminate the drum 12 at each end.

To facilitate a welded connection between wall parts 15 and 16, and strengthening bars 19, the edge regions of the wall parts 15 and 16 fit in channels 21 of the strengthening bars 19, which are preferably formed as extrusion profiles.

Each strengthening bar 19, which has a circular, angular, or oval cross-section, defines a recess 17 over the entire length of the bar, which is the same shape as the cross-section of the contact bar 18. There is a channel 21 on both sides of this recess to receive walls parts and 16, which are welded with the strengthening bars 19 to the inside and outside of the drum, in the region of these channels 21.

Each contact bar is formed from two cathode rods which are arranged coaxially, and are electrically connected, each rod having a circular cross-section.

To agree with the cross-section shape of the cathode rods, each strengthening rod 19 has a partially circular recess in which the two coaxially running cathode rods 18 are mounted, and from which part of their surface projects is exposed to make contact with the shaped parts to be galvanized.

The heart shape of the pendulum drum 12 is formed by the four wall parts 15 and 16, which are connected together by three strengthening bars 19. The two adjacent partially circular (annular) shaped wall parts 15 represent the floor region of the drum l2, and to each wall part 15 the curved part of a wall part 16 is connected the rectilinear regions of the wall parts forming the opening 14 at the top.

The ends of the strengthening bars 19 fit into recesses 22, which extend part way through the ends 20.

The wall parts 15 and 16 are braced on the inside of the drum by ribs 23, and in the region of the filling and emptying opening 14, by exterior bars 24. I

The wall parts 15 and 16, the strengthening bars 19, the end walls 20 and the stiffening ribs 23, as well as stiffening bars 24 of the pendulum drum 12, are of plastics material such as polypropylene, and the wall parts 15 and 16 preshaped while hot.

The wall parts 15 and 16 extend in over the entire length of the drum; they can, however, be formed from several parts, extending over the longitudinal direction of the drum.

Each contact bar, which runs the entire length of the drum, and is formed from two coaxially arranged cathode rods 18, mounted in a common recess 17 of the strengthening bar 19, is held detachably in the drum 12, in the central longitudinal region or elsewhere, by a bridge 25 of non-conducting material; this bridge 25 consisting of plastics material, covers a joint between the two coaxial cathode rods 18, the joints including a spigot 18a of the adjacent contact bar. The bridge is fixed detachably according to position, by a bolt 26 which passes through the strengthening bar 19, and is secured by a nut screwed onto the outside of the drum, in the connection region of two cathode rods 18.

Each cathode rod 18, at its end away from the plastics bridge 25, passes sealingly through the end wall 20 of the drum, and is connected to a contact part 32 which is covered by an insulationlayer 28 which is insulated from the end wall 20 of the drum and fastened detachably to the outside of it; there is a terminal for an electric current supply line 31.

The contact part 32 is formed from a metal plate 29,

with the metal terminal 30 fastened on it, and an insulation layer 28, preferably of rubber, which surrounds this metal core 29 and the terminal 30 on all sides up to the points of contact with the cathode rods 18 and the current cable 31 (compare FIGS. 4 and 5).

The cathode rod 18 is fastened to the contact part 32 by a threaded end 33, and is detachably connected to the contact part 32 by a nut 35 which is screwed on to the outside of the end 33. The nut is covered by an insulation cap 34; the contact connection between cathode rod 18 and contact part 32 takes place inside the bore of the metal core 29, which accepts the threaded end 33.

The contact part 32 provided on the outside of each end wall 20 of the drum extends part-circularly around the bearing axis 13 of the drum, and isdetachably fastened by means of several screws 36 which penetrate through bore-holes covered by the insulation layer 28, and by nuts 37, to the end wall 20 of the drum.

The terminal 30 extends from an end region of the partially circular contact part 32, and has a hole 38 to receive a contact end 39 of the conductor 31, which is insulated against moisture. The contact end 39 is connected detachably to the terminal 30 by a nut 41 which is screwed onto the end 39 and which is covered by an insulation cap 40. All cathode rods 18 are supplied with current by this terminal 30, one of which is provided on each contact part 32.

The carrying frame 10 is formed from two carrying plates 43 which are connected together by tie rods 42, and accept the stub shafts 13 of the drum. On this carrying frame 10 is mounted a propulsion device 44, a driving motor with gearing, which is connected, by its driving pinion 45 via an intermediate wheel 46 to a toothed wheel 47 which is fastened to one end of the drum. The motor drives the pendulum drum 12 with a rocking (to and fro) movement.

The carrying frame 10 has two carrying plates 43 with two pins 48 with which the carrying frame 10 and its pendulum drum 12 can be suspended as a unit in the forks 49 of a treatment bath container 50, a filling or emptying container, a drying kiln, a transport device 51 or the like.

Each carrying frame plate 43 has a conductor rail 52 to which thecurrent conductor 31, which leads to the contact part 32, is connected. The current supply for the pendulum drum 12 is derived from a low voltage source with a high current output (eg 750 amp. at 15v). The current is brought to the conductor rail 52, in each case via a current supply line 63 which is connected to the forks 49, and the pins 48 enclosed therein, from which the current reaches the cathode rods 18 via the line 31 connected to it (and via the insulated contact part 32).

The current supply for the propulsion motor 44 is separately derived from a connector 53 which is located at one end of the frame 10. This connector 53, upon insertion ofthedrum 12 in the bath container 50, is connected to a complementary part 54 which is arranged on the container three-phase current is used for the propulsion motor 44, the current being fed through a line 64 of the counter-contact device 54.

On the front of the drum facing the gear motor 44, there is a plastic index ring 55 surrounding the stub shaft 13, to which several metallic switching plates 56, 57 and 58 are fastened, which cooperate with a commutator 59 fastened detachably on the container 50 for control of the drum 12 between its two end positions, and the filling or emptying position. The commutator has an index ring 55 on which there are two metal plates 56, two metal plates 57 and one metal plate 58, which are spaced from one another, and at three different diameters, two approximately diametrically opposite metal plates 56 of which are arranged on the smallest diameter, and serve to limit the extreme pivotal positions of the drum. Two further metal plates 57 which are also approximately diametrically opposite, and are displaced against the direction of rotation of the drum in relation to the metal plates 56, represent security contacts, and are situated at the largest diameter.

A metal plate 58, which is arranged on the medial diameter between the four previous contacts, forms a contact for the location of the pendulum drum 12 in its emptying position.

The commutator 59 has two fixed brushes 60 and 61, which are spaced apart, the brush 60 being on the diameter of the metal plates 56, and the brush 61 on the diameter of the contact 57. These brushes 60 and 61 are so located that in the event of their touching one of the contacts 56 and 57, the motor 44 for rotating the drum is switched off and reversed, or switched right off in an emergency.

lfthe metal plate 56 is contacted by the brush 60, the drive of the drum in one direction is terminated, and the motor 44 is reversed to produce the opposite rotation of the drum. If the brush 60 fails, or if one of these metal plates 56, through a defect in the brush 60 overruns the latter, the metal plate 57 encounters brush 6] after a small further rotation of the drum l2, and the rotation of the drum is arrested.

To empty the drum 12, the latter is rotated until the excitation plate 58 is situated between the two brushes 60 and 61; this brings the motor to a standstill.

The pendulum drum 12 is divided into two or more chambers by one or more dividing walls 62. The dividing walls 62 are removably inserted in the drum 12, and can be pushed along the longitudinal direction of the drum into the desired position; they can be fixed in position by fastening means, such as screws, clamps or the like. When the separating walls 62 are removed, long work pieces can be treated. The shiftable dividing walls 62 make possible the formation of chambers of optional dimensions.

The dividing walls 62 enable workpieces of various types to be treated separately in the drum 12.

The plating device described can be incorporated in a plating installation having several stations arranged one after the other.

There has been disclosed heretofore the best embodiment of the invention presently contemplated. However, it is to be understood that various changes and modifications may be made by those skilled in the art without departing from the spirit of the invention.

What we claim as new and desire to secure by Letters Patent is:

l. A galvanizing device comprising, in combination:

a. a supporting frame;

b. an oscillating drum mounted in said supporting frame for reciprocating, angular movement, said drum having passage apertures for a galvanic medium formed in the walls thereof;

c. said oscillating drum in cross-section having several wall portions connected together so as to define a heart-shaped filling and emptying opening;

d. said wall portions with their adjacent longitudinal edges each being rigidly secured to a reinforcing profile that extends over the whole length of said drum;

said wall portions and said reinforcing profiles being rigidly secured to the end faces of said drum thereby closing said oscillating drum; v

f. said reinforcing profiles at the same time forming bearing points for contact rod assemblies located within said oscillating drum, said reinforcing profiles enclosing part of the cross-section of said contact rod assemblies;

g. over the length of the drum two contact rods being arranged in rectilinear extension, said two contact rods being detachably secured by a bridge made of a non-conduting material and a' screw connection to the inside surface in the region of said reinforcing profiles;

h. the ends of each of the said contact rods extending through said end faces of the drum and being connected to an insulated contact member, having an electric coupling member, secured to the outer surface end wall of the drum;

i. said contact member being formed by a metal plate member extending partially about the pivotal axis of the drum and an insulating layer enclosing the plate member with the exception of the contact points on all sides.

2. A galvanizing device as claimed in claim 1, in which said oscillating drum is formed of two wall sections of pitch circle-shaped cross-section and two menate wall sections adjoining the pitch-circle-shaped wall sections at a rectilinear region whereby the two pitch circleshaped wall sections form the base region of the drum and the two other wall sections form the lateral region, whereby the lateral regions of the wall sections define the filling and emptying opening.

3. A galvanizing device as claimed in claim 2, wherein said wall sections of said drum are reinforced on the inside by ribs and, in the region ofsaid filling and emptying opening by external bars, each wall section forming the cross-sectional form of the drum over the whole length of the drum being made in one piece.

4. A galvanizing device as claimed in claim 1, wherein each contact rod assembly extends over the whole length of the drum and is formed by two cathode bars located in a common mounting recess which are interconnected in the center longitudinal region of the drum by said bridge and provided with a pin overlapped at the end face by said bridge and said bridge, by means of said screw connection including a screw passing through said reinforcing profile and a nut screwed thereon outside said drum, being located in position anddetachably retained in said drum.

5. A galvanizing device as claimed in claim 1, wherein said coupling member of said contact member is provided in an end region of the metal plate member and in a bore receives a contact pin of the electric lead insulated against dampness, whereby said contact pin is connected detachably to the coupling member by a nut screwed thereon and covered by an insulating cap.

Claims (5)

1. A galvanizing device comprising, in combination: a. a supporting frame; b. an oscillating drum mounted in said supporting frame for reciprocating, angular movement, said drum having passage apertures for a galvanic medium formed in the walls thereof; c. said oscillating drum in cross-section having several wall portions connected together so as to define a heart-shaped filling and emptying opening; d. said wall portions with their adjacent longitudinal edges each being rigidly secured to a reinforcing profile that extends over the whole length of said drum; e. said wall portions and said reinforcing profiles being rigidly secured to the end faces of said drum thereby closing said oscillating drum; f. said reinforcing profiles at the same time forming bearing points for contact rod assemblies located within said oscillating drum, said reinforcing profiles enclosing part of the cross-section of said contact rod assemblies; g. over the length of the drum two contact rods being arranged in rectilinear extension, said two contact rods being detachably secured by a bridge made of a non-conduting material and a screw connection to the inside surface in the region of said reinforcing profiles; h. the ends of each of the said contact rods extending through said end faces of the drum and being connected to an insulated contact member, having an electric coupling member, secured to the outer surface end wall of the drum; i. said contact member being formed by a metal plate member extending partially about the pivotal axis of the drum and an insulating layer enclosing the plate member with the exception of the contact points on all sides.

2. A galvanizing device as claimed in claim 1, in which said oscillating drum is formed of two wall sections of pitch circle-shaped cross-section and two arcuate wall sections adjoining the pitch-circle-shaped wall sections at a rectilinear region whereby the two pitch circle-shaped wall sections form the base region of the drum and the two other wall sections form the lateral region, whereby the lateral regions of the wall sections define the filling and emptying opening.

3. A galvanizing device as claimed in claim 2, wherein said wall sections of said drum are reinforced on the inside by ribs and, in the region of said filling and emptying opening by external bars, each wall section forming the cross-sectional form of the drum over the whole length of the drum being made in one piece.

4. A galvanizing device as claimed in claim 1, wherein each Contact rod assembly extends over the whole length of the drum and is formed by two cathode bars located in a common mounting recess which are interconnected in the center longitudinal region of the drum by said bridge and provided with a pin overlapped at the end face by said bridge and said bridge, by means of said screw connection including a screw passing through said reinforcing profile and a nut screwed thereon outside said drum, being located in position and detachably retained in said drum.

5. A galvanizing device as claimed in claim 1, wherein said coupling member of said contact member is provided in an end region of the metal plate member and in a bore receives a contact pin of the electric lead insulated against dampness, whereby said contact pin is connected detachably to the coupling member by a nut screwed thereon and covered by an insulating cap.

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