US2578251A - Arrangement for regulating the voltage of a galvanic bath - Google Patents

Description

J. KALIN Dec. 11, 1951 Filed Jan. 7, 1948 A INVENTOR. 0 M

Patented Dec. 11, 1951 UNITED STATES PATENT OFFICE ARRANGEMENT FOR REGULATING THE VOLTAGE OF A GALVANIC BATH 3 Claims.

The present invention relates to an arrangement for regulating the voltage of a galvanic bath. It has for its object to keep the potential between anode and cathode constant within a range which produces the most favourable effect as regards the galvanising action. It is known that. when the potential is too low, the output is correspondingly smaller, but when the potential or voltage is too high, the galvanic coating is of poor quality, since it forms then a foamy texture and thus appears to be dark to black in color and is also not durable.

The arrangement according to the invention for regulating the potential. or voltage in galvanic baths is characterised by a voltage relay connected between anode and cathode and an auxili'ary current circuit for the actuation of at least one regulating resistance, said auxiliary current circuit being controlled from the voltage relay.

One construction of the arrangement according to the invention shows by example two regulating resistances as indicated diagrammatically in the accompanying drawing.

1 is a galvanic bath with the two pole leads 2 and 3 connected to a current source 4. The latter may, for example, consist of a direct current dynamo, an accumulator battery or a rectifier. It is important, however, to regulate the terminal voltage delivered by this current source, as shown in the drawing 4. The current source is a regulatable shunt generator with the connecting terminals 5, but, it could also be an accumulator battery (not shown) controlled by means of battery switches. 6 is an auxiliary current source,

the energy of which serves for the actuation of the regulating or compensating resistances. The leads from this auxiliary current source 8 are indicated by l and 8. 3 is a switch that is controlled by a solenoid in which is actuated from the main leads 2 and 3.

A voltage relay H, which is connected to the two main leads 2 and 3 by means of the leads l2 and I3, serves the purpose of giving the impulse for the regulation of the voltage in the bath l. The relay l includes a contact arm i4 which, depending upon an undervoltage or an overvoltage in the bath l, causes the closing of circuits by contacting the respective contacts l5, I6, which circuits include the solenoids H and I3. These current circuits are branches from the auxiliary current leads l and 8, Depending upon whether contact i5 or contact i6 is connected with the contact arm l4, a lead l3 or 23 will be placed under current, since the latter closes the respective switches 2! and 22 by action of solenoids I1 and i8, respectively. Lead {9 leads to the pivot point of a first tilting switch 23 and the lead to the pivot point of a second tilting switch 24.

Connected to the main lead 3 is a compensating resistance 25, the switch arm 26 of which serves at the same time as actuating member for the tilting arms 23, 24. In their normal position, the tilting switches 23, 24 are forced under the influence of springs (not shown in the drawing) towards contacts 2'! and 28 respectively. From these contacts 2'! and '28 the leads 29 and 30 pass to solenoids 3| and 32, respectively, the opposite poles of which are both connected to the auxiliary current lead 1. These solenoids 3| and 32 serve for the mechanical actuation of switches 33, 34, 35 and 36 controlling the armature current of a motor 31 which, through its shaft 38 and a gear drive (not shown, but consisting, for example, of a worm transmission), actuates the switch arm 26. The armature windings are indicated by 39 and the field windings connected with the auxiliary current leads I and 8 by means of the leads 46. Instead of the field windings 40 always being kept under current when the motor 31 is not operative, thereby consuming current unnecessarily and heating up the exciter coils, it is also possible to incorporate interrupters in these leads 4!], said interrupters automatically becoming operative as the motor stops.

For the mechanical actuation of the switches 33, 34, 35 and 36, these are coupled with the cores of the solenoids 3| and 32 by insulating elements 4! and 42, the solenoid 3i actuating the switches 33 and 34 and the solenoid 32 the switches 35 and 36.

If the switch arm 26, according to the drawing, is moved towards the left (see drawing) until it swings the tilting arm 23, then the latter comes into contact with a contact 43 to which is connected the lead 44. Conversely, if the switch arm 26 is moved into the opposite end position, then it is the tilting. lever 24 that is swung and thus comes up against a contact 45 from which the lead 46 extends.

The compensating or regulating resistance, with the associated motor for actuating same and the switches actuated bysolenoids are represented as the first regulator aggregate RI. A similarly constructed second regulator aggregate RII is provided in order to regulate the terminal voltage of the bath current source. The latter aggregate receives the impulse from the abovedescribed first aggregate through the leads 44 and 46.

This. second regulator aggregate RII again. consists of a compensating resistance 4! with a switch arm 48, the former being connected by the lead 49 to the pole lead 3 and the switch arm 48 being connected by the lead 50 to the connecting terminals 5. The actuation of the switch arm 48 is likewise effected by a motor through a shaft 52 by means of a gear drive (not shown). The switch arm 48 also serves, in the end positions, to operate two tilting switches 53 and 54, which, in their normal position, bear under spring action against contacts 55 and 56 which are connected to the leads i4 and 46-, respectively, coming from the first regulator aggregate RI. Leads 5'! and 58 extend from the tilting switches 53 and 54 to solenoids 59 and 60 which are connected at their other sides to the auxiliary current lead i. mechanical actuation of switches 6|, 62, 63 and 64, which are provided for the control of the armature current of the motor 5|. In this arrangement, the solenoid 59 is coupled with the switches 6| and 62 by way of an insulating connection 65 and the solenoid 60 with the switches 63 and 54 in such a manner that the switches 5| andB-Z or 63 and 64, respectively, are switched on or off, respectively, by the response of the solenoids 59 or 6B. The armature leads to the motor 5| are indicated at 61 and the field leads at 58, the same remarks applying to the latter as regards interruption as for the field leads 48.

69 are frames for receiving the compensating resistances and the rectangles 70, I0 and 10 in dotted lines represent instrument tables.

The arrangement illustrated operates in the following manner:

First of all, the bath current is switched on and thus the anodes and cathodes are supplied with current. The auxiliary current circuit is also closed by this action by means of the switch 9. When the bath is not charged, the voltage therein is approximately equal to the idle running voltage delivered by the current source 4. By charging the bath with articles to be galvanised, the voltage between anode and cathode drops in proportion to the surface area of the articles. In order to prevent an unnecessary oscillating operation of the arrangement with the bath uncharged, inasmuch as the bath voltage may be somewhat too high despite the resistances even when being fully switched on, one plate of the said bath serving as anode, or a sufficiently large iron or copper sheet, suspended as a so-called current screen on the cathode side, may be used for lowering the voltage. The voltage in the bath drops upon charging, whereby the voltage relay H is set in motion until its contact arm i4 comes to rest against one or the other contact H5 or H5, according to whether there is an undervoltage or overvoltage with respect to a mean operating voltage. Assuming that there is contact at i5 as a result of an undervoltage, then a circuit is closed between the auxiliary leads I and 8 by way of the solenoid ll. By closing the switch 2|,

a current circuit is closed from the lead 8, through this switch 2|, the lead i9, the tilting switch 23' and, from this, by way of the contact 27, the lead 29 and the solenoid 3|, to the lead I. 'In this way, the solenoid 3i actuates the switches 33 and 34 in the closing direction. The motor 31 receives armature current and actuates the switch arm 26 inthe direction for switching or cutting'out resistances 25, whereby the bathvoltage is raised. If the resistance is switched out as far as the end position, without the bath volt- -age being raised sufiiciently, thenzthe tilting lever These solenoids 59 and iii! serve for the,

23 is moved by the switch arm 26 in such a manner that the afore-mentioned circuit is opened at 2? and thus the motor 31 comes to a stop. On the contrary, if the tilting lever 23 comes up against the contact 43 and conducts the current coming from the lead 8 through the lead 44 to the contact 55 in the second regulator aggregate R11 and from thence, by way of the tilting switch 53 and the lead 57, to the solenoid 59, which is connected on its other side with the lead 1, and thus its circuit is closed. Consequently, this solenoid 59 responds and closes the switches 6| and 62, thereby supplying armature current to the motor 5|. This raises the field voltage of the shunt generator 4 by such an amount that the 'potential'between the pole leads 2 and 3 is increased. In the end position of the switch arm 48, the tilting lever 53 is interrupted and consequently the supply of current from the auxiliary supply 1, 8 to the armature of the motor 5| is interrupted.

The dimensions of the resistances and 41 are such that in their limiting positions, even with the bath fully charged, there is a sufiicient voltage in said bath.

If an overvoltage exists in the bath, due, for example, to the articles being removed thereir the switch arm i4 is moved against the contact i6. Upon coming into contact therewith, the switch 22 is closed by the solenoid l8 and the current flows from the lead 8 through the lead 20 towards the tilting lever 24, and, through the lead 36, actuates the solenoid 32, which closes the switches and 36, whereby the motor .5? receives armature current causing the motor 3? to turn in opposite direction so that it places resistance 25 into the main circuit. In the end position of the arm 26, the lever 24 is disconnected from contact 28 and passed over to the contact ii-whereby the current flows through the lead it to the contact 56, through the tilting switch 55 and the lead 58 to the solenoid 69. This closes the switches 53 and 64, and consequently supplies armature current to the motor 5! in such a manner that the resistance lis placed in circuit and thus the potential between the pole leads 2 and3 is lowered.

It has been shown in practice that the switches 2! and 22 actuated by the solenoids I1 and 18 are not absolutely necessary, but the'contact members It or it, respectively, could be placed directly on the leads i9 and 20, respectively, so that the current of the auxiliary circuit from the lead '1 is led directly to the tilting switches 23 or 4, respectively, by way of the switch arm M on the relay Ii. r

The limits of the voltage to be maintained are adjusted in practice by displacing the contact members is and I6 towards or away from one another, since the voltage range is reduced by bringing these contact members closer together and increased by moving them apart. 1

Moreover, with the arrangement described, several baths may also be controlled simultaneously as regards voltage, it being pre-supposed, of course, that all the baths have the same'voltage requirements.

Furthermore, the installation may also be so provided that several baths are served from a single source of bath'currenu-even if the individual baths require different voltages. In this case, each bath is, for example, controlled from a separatefirst regulator device, all orwhic-h are th v connected with t-hecommon regulator device ior-themaincurrent supply 2, 3. :1

Depending upon the form of the bath current source, the second regulator aggregate can be dispensed with and replaced by a press button control means.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. In an arrangement for regulating the voltage of a galvanic bath, a power source, a first circuit connecting the power source with said galvanic bath, a second circuit, a second energy source and at least a first regulating aggregate in said second circuit, said aggregate compris ing a first variable resistance and an electric motor, the armature coil of said motor being in said second circuit, the first variable resistance of said first aggregate being in said first circuit and a second variable resistance of a second aggregate controlling the field voltage of a shunt generator forming said power source, said second variable resistance being put into operation upon disconnecting the control means of said first variable resistance, each electric motor controlling the corresponding variable resistance, switch means responsive to the voltage in the first circuit to reverse said armature coil of each motor in the second circuit, and means controlled by the respective variable resistances to open the circuit to the corresponding armature coil of each motor.

2. The arrangement as set forth in claim 1, in which the variable resistance of the first aggregate controls switch means for disconnecting at a predetermined point of said resistance the first aggregate and for connecting the second aggregate.

3. In an arrangement for regulating the voltage of a galvanic bath, a power source, a first circuit connecting the power source with said galvanic bath, a first variable resistance in the first circuit, a voltage relay between anode and cathode of the bath controlling the first resistance, a second variable resistance controlling the terminal voltage of said power source and being controlled by the first resistance, a second circuit including a second energy source and armature coils for motors controlling the first and second resistance, respectively, switch means controlled by said voltage relay for reversing the armature coils in the second circuit and means controlled by the first resistance for disconnecting at a predetermined point thereof the armature coils of the motor controlling the first resistance and connecting the armature coils of the motor controlling the second resistance.

JOSEF REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 903,580 Knapp Nov. 10, 1908 921,299 Sprong May 11, 1909 1,197,178 Bliss Sept. 5, 1916 1,709,757 Ohlson Apr. 16, 1929 1,738,102 Guttinger Dec. 3, 1929 1,873,761 Gulliksen Aug. 23, 1932 2,046,990 Woodrow July 7, 1936 2,076,499 Grant Apr. 6, 1937 FOREIGN PATENTS Number Country Date 266,798 Great Britain Feb. 28, 1927

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