US2538242A - Apparatus for processing workpieces - Google Patents

Description

Jan. 16, 1951 A. H. HANNON APPARATUS FOR PROCESSING WORKPIECES 5 Sheets-Sheet 1 Filed March 11, 1948 INVINTO H ALBERT H. HANNON BY A TTO RN 5Y6 Jan. 16, 1951 A. H. HANNON APPARATUS FOR PROCESSING WORKPIECES 5 Sheets-Sheet 2 Filed March 11, 1948 mvln'rog ALBERT. H. HANNQN JW QJM ATTORNEYS Jan. 16, 1951 A..H. HANNON APPARATUS FOR PROCESSING WORKPIECES 5 Sheets-Sheet 3 Filed March 11, 1948 lNVENTOH AL BERT H. HANNON ATTOHN EYS Jan. 16, 1951 A. H. HANNON APPARATUS FOR PROCESSING WORKPIECES 5 Sheets-Sheet 4 Filed MarCh 11, 1948 luvsu'ron ALBERT H. HANNON ymaw-m g m ATTORNEYS Jan. 16, 1951 A. H. HANNON ,5

APPARATUS FOR PROCESSING WORKPIECES Fild March 11, 1948 5 Shee ts-Sheet 5 M/vErvroIr .ALBERT H- HANNON ar- I I mum-M dam ATTORNEYS Patented Jan. I 16, 1951 UNITED STATES PATENT OFFICE APPARATUS FOR PROCESSING WORKPIECES,

Albert 11. Hannon, Springfield," Ohio, assigiror to Frederic B. Stevens, Inc.,

Michigan a corporation of Application March 11, 1948, semi No. 14,356

. production setups. In the case of all such members which are exposed to the atmosphere or to other corrosive influences, itis preferable that they be electro-plated with a coating which will inhibit or prevent rusting, corrosion or deterioration.

Due to the fact that work members of this nature are quite small and, as pointed out above, must be produced in great quantity, it is not feasible to process them by individual handling. Accordingly, any electro-processing such as plating must be carried out on the workpieces in bulk.

Because of the difliculty of applying the plating material to the entire surface of small Workpieces being handled in bulk, they are often improperly coated at the end of the processing operation. 'Numerous attempts to design satisfactory plating machines for handling small workpieces in bulk have been made, but the resulting apparatus have not been entirely satisfactory.

Machines of this nature include barrel type machines in which" the workpieces are placed in bulk in a perforated barrel which is immersed in or carried through a processing tank or tanks and which is rotated or oscillated in order to agitate the workpieces therein so that the entire surfaces are exposed to the processing action.

Machines of this nature are relatively expensive, involve the problem of loading and unloading the barrels, and are not particularly adapted for certain automatic plating processes because of the great difference in the lengths of time that 9 Claims. (Cl."204 202) complished in from three to five minutes, while the nickel plating will require from twenty minutes upwardly.

In the usual type automatic barrel machine, the nickel tank is therefore apt to be from four toeight times as long as the copper tank. It will be evident that this would result in an unusually large machine with considerable waste space. Also, in barrel type machines there is considerable carry over of solution from one station to another unless each barrel is allowed considerable time to drain before it passes from one tank to another.. This is especially true in connection with very small workpieces when the perforations in the barrel must be quite small.

Another disadvantage which is encountered in barrel type machines is that the area of the path the workpieces must be subjected to the different for electric current through the electrolyte is greatly restricted by the small holes in the barrel. Thus, for an electric plating cycle requiring possibly twoor three volts of actual potential, it is. customary to supply as much as 12 volts, the excess voltage being required in order to carry sufiicient current through the restricted path between the anodes and workpieces and through the relatively small apertures in the walls of the barrel.

The. primary object of the present invention is to provide an improvedmethod and apparatus especially adapted for processing small workpieces in bulk.

Another object of this invention is to provide an 'electro-processing unit adapted for handling small workpieces in bulk and which can be arranged in multiple with other similar units for an automaticplating cycle.

Another object is to provide an electro processing machine for small workpieces in which the workpieces are handled in bulk but in which the loading and unloading of barrels and similar containers isentirely eliminated A still further object is the provision of a bulk electro-processing apparatus for small workpieces in which the entire surface of all of the workpieces is exposed to the processing action. These and other objects and advantages will become more apparent upon reference to the following description taken in connection with the accompanying drawings in which:

1 Figure 1 is a side view of a machine constructed according to this invention;

Figure 2 is a plan view thereof;

Figures 3 through 6 are fragmentary views showing details of construction in connection with the machine;

Figures '7 and 8 are fragmentary views showing modified constructions of the conveyor belt for the machine;

Figure 9 is a partial view showing how two or more of the machines can be manifolded for automatically discharging the contents of one machine into another;

Figure 10 illustrates a modified construction wherein a single conveyor belt is arranged to pass,

through 9, plurality of processing tanks;

Figures 11 and 12 are views showing howthe drive between the conveyor belt supporting-pulleys and the conveyor belt can be made more positive; I

Figure 13 is a diagrammatic view showing the electrical circuit for controlling the processing machine; and

Figures 14 and 15 are plan and side views, respectively, of a typical automatic setup employing a plurality of unit machines according to this invention.

General arrangement Pulleys at the edges of the tank support. the

conveyor belt and power is supplied to one or both of the pulleys for driving the belt.

The conveyor belt is preferably of corrugated construction and has side rails formed integrally therewith. The cathode extends into the tank and transversely across the bottom thereof above the conveyor belt and suitable anodes are also suspended in the tank.

workpieces placed on the conveyor belt in the tank rest on the lower part of the conveyor belt and cover the cathode and are thus contacted by the said cathode.

To expose the surface of all of the workpieces to the anodes the conveyor belt is oscillated be tween predetermined limits.

Due to the slope of the belt at the sidesof'the tank, the workpieces will be carried part way up the side of the tank by the belt and then will roll back. By oscillating the belt the work-piecesare rolled back and forth over the cathodeand over afiredetermined period of time will have their entire surfaces exposed to the anodes.

After the plating cycle is completed the con- 7 veyor belt is run continuously in one direction and unloading cleats carried thereby carry the workpieces out of the tank and discharge them over one of the conveyor belt supporting pulleys.

The tanks may be arranged in pairs side by side and with their conveyor belt supporting pulleys mounted on a common shaft and with a single power source connected for driving said pulleys.

This arrangement permits the individual tanks to be employed for separate plating cycles as, for example, one tank carrying out a copper plating cycle and the other tank carrying out a nickle plating cycle. The workpieces after being plated in one of the tanks are removed therefrom and undergo a hand rinsing operation and then are placed in the other of the tanks.

According to one modification, the discharge end of one tank is elevated and extended so that the workpieces discharged from the said tank will fall directly into the tank of another unit setting end to end with the first unit.

According to another modification, the end to end relationship of the tanks may be accomplished in an integral unitand a single conveyor belt is arranged to pass through both of the said tanks.

Structural arrangement Referring to the drawings somewhat more in detail, Figures 1 and 2 show the preferred construction fora single unit machine according to this invention, and wherein there are the tanks H) and 12 which are arranged side by side and each of which is substantially V-shaped in cross section but with an arcuate bottom portion.

Supported at each edge of the tanks, as upon the bracket means I4, are the pulle shafts I6 which carry the pulleys l8 over which the conveyor belts 20 pass.

The conveyor belts 20 are formed of arubber or rubber like composition and have their outer surfaces corrugated as at 22 and also preferably comprise the upstanding side parts 24, the purpose of which will become more apparent hereinafter.

For causing thebelts 20 to follow the contour of the inside of the tank through which it passes, the said tank has secured to each side wall adjacent the bottom and overlying the belt a guide member 26 which is in effect an arcuate shoe which acts as a hold-down for the said belt.

Externally of the tank, the belt 20 passes over an idler puliey 28 mounted at the bottom of the tank and urged by springs 30 to maintain a predetermined tension in the said belt.

The belts 20 also have formed thereon a plurality of cleats or rib members 32 which, as shown in Figure 1, are grouped about the idler pulley 28 so that normally they are positioned outside the processing tank. However, when the belt 20 is run continuously in either direction the cleats 32 will be carried through the tank and carry the workpieces therein out and over one of the pulleys l8 and thereby discharge them from the tank.

For electro processing cycles, there is a cathode 34 carried on the tank and extending downwardly therein and across the bottom space a predetermined distance above the belt 20.

The vertical portion of the cathode 34 is preferably coated by a rubber or other insulating composition as at 36, while the horizontal portion thereof extending across the bottom of the tank is left uncoated for making electrical contact with the workpieces in the tank.

Also suspended in the tank are a plurality of anodes 38 which are of the material which it is desired to plate on the workpieces in the tank. The suspension of the cathode and anodes in the tank are by customary methods and it will be understood that they are electrically insulated from each other and from the tank.

For example, Figure 3 shows the support for the cathode and it will be evident that the cathode bus bar 40 is in electrical contact with the cathode 34 but is insulated from the tank I!) by means of the insulating sleeves, bushings, and washers generally indicated at 42.

Similarly, the hanger rod 44 for the anodes is in electrical contact with its bus bar 46 but is insulated from the tank H) by the insulating material indicated at 48 in Figure 4. As shown in Figure 'l the anodes 38 are positioned in tank trically isolated from the pipes 52.

To complete the isolating of the tank from other parts of the apparatus, the, journals in which the roller shafts l6 are mounted, and the supporting frame work 58 for the tank, are both connected with the said tank as illustrated in Figure 6 wherein the insulating bushings and washers 60 effectively electrically isolate the connected members.

As will be seen in Figures 1 and 2, the pulleys l8 are adapted for being driven by a motor 62 which has an output pulley 64 connected by a belt 66 with a pulley 6B which is connected to drive through a gear reduction unit 10 into the pulley shaft at the motor end of the machine.

For driving the pulley shaft at the opposite end of the machine there is a second gear unit 12 which is connected with the unit 10 by the jointed shaft 14.

The speed of operation of the pulley shafts is adjustable by the screw means 16 which is rotatable for vertically adjusting the position of the motor 62. When the motor 62 is so adjusted the pulley 64, and which is any of several well known types of variable speed pulleys, automatically adjusts the distance between its opposite faces to permit the belt 66 to run on a greater or smaller diameter thereof.

In operation, a quantity of the proper electro- V lyte is placed in the tank and anodes of the proper material are mounted on the anode hangers. Thereafter a quanity of small workpieces in bulk are placed within the tank as indicated by the outline marked 18 in Figure 1.

The temperature of the electrolyte is adjusted if desired by steam or cooling water which is passed through the pipe 50 and the generator 80 connected between the cathode and the anode is then started or connected to the cathode and anode to supply the proper current and voltage thereto.

The motor 62 is conveyor belt and, as will be more fully explained hereinafter, operates to oscillate the belt between predetermined limits.

During the oscillation of the belt the workpieces will be carried up each side of the tank and then will roll back toward the bottom of the tank due to the angular incline of the conveyor belt. It will be evident that this will cause all of the surface of all of the workpieces at one time then energized to drive the or another to be exposed to the anodes and therefore to be plated by the material therefrom.

After a predetermined number of oscillations of the belt and during which time all of the workpieces are plated all over, the belt is permitted to run continuously in one direction thereby to carry the unloading cleats. 32 through the tank and to carry the, workpieces from the tank. When the workpieces have been carried from the tank a new supply of workpieces can be placed in position and a new plating cycle commenced.

As shown in Figure 9, the pulley at the discharge end of the machine can be elevated and extended by means of the brackets 80 and 82 and a slide or chute 84 mounted in such a position thatthe workpieces being discharged from one tank will be received in the next. By the arrangement shown in Figure 9 as many plating steps as desired can be carried out and the workpieces are only handled at the inlet and discharge end of the machine.

7 The unloading cleats are preferably perforated or otherwise open to the passage of the solution therethrough so that the solution will not be displaced from the tank when the workpieces are discharged therefrom. I This may be accomplished by forming the cleats integrally with the belt and perforating them, or by providing the belt with lugs as indicated at 86 in Figures 7 and 8 and to which can be attached a cleat member such as the perforated wooden bar 38 in Figure 'l or the screen member 90 in Figure 8.

Inasmuch as electrolyte solutions sometimes are rather oily or slimy, it may be desirable to provide means for making the engagementof the pulleys I8 with the conveyor belt more positive. Means for accomplishing this are shown in Figures 11 and 12.

In Figure 11 the belt 20 is shown as being cogged as at 92 on the underneath side while the pulley I8 is formed with the cogs 94. By this engagement of the conveyor belt by the pulley there will be no slipping therebetween.

In Figure 12 the pulley I8 is shown as having a knurled or roughened surface 96 which engages the underneath side of the belt 20.

For less severe service the Figure 12 arrangement will provide a more economical manner of providing adequate driving engagement of the belt 2!) by its supporting pulleys.

In some instances it may be desirable to manifold the tanks into pairs as shown in Figure 10. In Figure 10 there are the tanks 98 and use which are arranged end to end so that a single pulley IE2 therebetween suflices for supporting the conveyor belt. Because of this a single conveyor belt I04 can be employed which passes through both of the tanks and then extends across beneath the tanks.

In the Figure 10 arrangement the workpieces in each of the tanks are processed simultaneously and thereafter when the workpieces are discharged from one of the tanks, the workpieces in the other of'said tanks are transferred to the said one tank for a further operation thereof.

The control of the motor 62 for any of the modifications of Figures 1, 9 or 10 can be accomplished by the electrical circuit diagrammatically illustrated in Figure 13.

In Figure 13 the motor 32, and which is of the electrically reversible type, is shown as connected between the power lines LI and L2.

For controlling the connection of the motor 52 to the power line L! through either the wire Hi6 which will cause it to operate in one direction, or through the wire I08 which will cause it to operate in the other direction, there are a plurality of relays indicated at A, B, C and D.

The relay at A is adapted for being energized upon the closure of a limit switch LSI, which is shown in Figure 1 and which is positioned to be actuated by the unloading cleat 32a as the belt oscillates in a direction to carry the said cleat upwardly toward the said limit switch.

When the relay A is so energized, a holding circuit therefor is established through the branch line H0 through the normally closed blade Bl of the relay B and the blade Al of the relay A which is closed when the said relay is energized.

Energiz'ation the relay. .A also 'open'sthe blade A2 thereof which will deenergize the relay B if the same is energized at that time, and also closes blade A3 which will complete a circuit through the relay coil C.

Energization of relay will bring about the closing of the blade CI thereof in the line I06 and the opening of the blade C2 thereof in the line I08.

As previously mentioned energization of relay A will bring about de-e'nergi'zation of the relay B if the same is energized thereby closing the blade BI thereof and opening the'blad'es B2 and B3 thereof. The blade B3 is in circuit with the relay D and upon being opened de energizes the said relay. However, the relay D is by-passed by the time delay circuit including the rheostat H2 and the condenser H4 and will only open after a predetermined time delay.

When the relay D becomes fully deenergized and opens it closes the blade DI thereof and opens the blade D2. Closure of the blade DI, since the blade CI is now closed, will energize the motor 62 through the line I66 to cause it to run in one direction.

The direction in which the motor 62 now runs Will be such that the belt will be reversed to move the cleat 32a downwardly from the switch LSI, and rotation of the motor in this direction will continue until the cleat 32b actuates the limit switch LS2.

Closure of the limit switch LS2 energizes the relay Bv to open the blade BI thereof thereby de-energizing the relay A; to close the blade 33? thereof thereby providing a holding circuit for the relay B; and to close the blade B3 thereof thereby energizing the relay D.

Energization of D will open the blade Di and close the blade D2 thereof. Opening of the blade DI will interrupt the circuit through the line I65 and de-energize the motor 62.

As mentioned above the relay A is de-energized and therefore the blade A3 thereof is opened to interrupt the circuit to relay C. However, due to the resistor IIS and the condenser H8 connected in parallel with the coil of relay C, the said relay will not be de-energized until after a predetermined period of time. Thus, the blade CI of the relay C does not open immediately and the blade C2 thereof does not close immediately. The motor 62 thus remains de-energized for a period of time and this period of time is calculated to permit the motor to coast to substantially a halted position.

After the time delay has expired and the relay C drops out the blade C2 thereof closes and establishes a circuit for the motor 62 through the line I08.

The purpose of the time delay circuits is to prevent the belt 20 from being reversed too suddenly which would place an undue strain not only on the belt but the pulley shafts and the gear units connected therewith.

When it is desired to unload the tank, the push button switch Hill is held open until all of the cleats 32 have passed the limit switch LSI. This prevents energization of relay A and permits the relay B to remain energized so the motor 32 is not reversed. After all of the cleats have passed the limit switch LSI the push button I28 may be released and thereupon the belt will continue to run until the cleat 32a again approaches the limit switch LSI and actuates it into closed position.

From the foregoing it will be evident that this invention provides for :a rocessing unit which can be arranged individually or in multiple for processing workpie'ees through baths including electroplating baths and that the arrangement is such that small workpieces such as nuts, bolts, and so-forth, which ordinarily are very difficult to process satisfactorily, can be handled with ease and adequately processed and plated at a rapid rate.

arrangement-of this feature is also adapted for plating cycles including multiple baths and plating steps as will be seen from the arrangement shown in Figures 14 and 15.

In Figures 14 and 15 there is'a first series 'of tanks indicated at I22 which may be individual units in the mannerof Figure 9, or manifoldecl units as shown in Figure 10 and wherein the workpieces are successively conveyed through a plurality of stations which may include alkali and acid treatments, a wash, and a final plating ste as, for example, a copper plating.

The arrangement in Figures 1a and 15 has a second group of tanks at E24 arranged in parallel and wherein a second plating step, as, for example, a nickel plating cycle is carried out. Since the nickel plating cycle is of much greater duration than the treatment given the workpieces as the tanks at I22, the said workpieces are unloaded at the left end of the last of the tanks I22 andare then divided into the four tanks at I24. The workpieces which are discharged from the tanks I24 are then again placed together and passed through the tanks at I26 which comprise neutralizing and washing baths.

The entire processing cycle to be carried out in the arrangement shown in Figures 14 and 15 can be accomplished with ease and with a minimum of handling of the work members and all of the tanks are substantially identical units. Thus, as many or as few tanks can be employed as it is necessary or desirable, and any arrangement thereof which is best suitable to the particular work cycle being carried out can be made.

It will be noted that the path between the anodes and the workpieces in the machine of this invention is not restricted by any interposed wall as in the case of the barrel type machines. Thus, a plating cycle requiring from 2 to 3 volts can be carried out by supplying a 6-volt generator and employing the usual type rheost-at for controlling the rate of current flow.

As mentioned before, a similar plating arrangement employing a barrel type machine would probably require a 12-volt current supply.

The difference in cost between 6 and l2-volt generators in a 500 ampere size would be 'sub stant-ial and, accordingly, the arrangement of this invention offers definite advantages in the cost of the original equipment.

It will be understood that this invention is susoeptible to modification in order to adapt it to different usages and conditions and, accordingly, it is desired to comprehend such modifications within this invention may fall within the scope of the appended claims.

I claim:

1. In a processing machine, a tank for holding a processing liquid, a belt extending through the tank and around the tank and carrying work agitating means'on that portion of the belt nor mally in the tank, members on said belt normally positioned outside of said tank, reversible driving means for driving said belt to agitate workpieces thereon in the tank, and means outside said tank actuated by said members for automatically re- 9 versing said driving means upon predetermined movement in either direction.

2. In a processing machine, atank for holding a processing liquid, a belt extending through the tank and around the tank and carrying work agitating means on that portion of the belt nor mally in the members on said belt normally positioned outside of said tank, reversible driving means for driving said belt to agitate workpieces thereon in the tank, means outside said tank actuated by said members for automatically reversing said driving means upon predetermined movement in either direction, and means selectively operable for biasing the direction of belt movement.

3. In a processing machine, a tank for holding a processing liquid, a belt extending through said tank along a V-shaped path for supporting workpieces beneath the surface of the liquid and ex-' tending around said tank and carrying work agitating means on that portion of the belt normally in the tank, members on said belt normally positioned outside of said tank, means outside said tank actuated by said members for automatically reversing said driving means upon predetermined movement in either direction, and time delay means controlling the energizing of the driving means during automatic reversing.

4. In a processing machine, a tank for holding a processing liquid, a belt extending through said tank and around said tank and carrying work agitating means on that portion of the belt normally in the tank, cleats on said belt normally positioned outside of said tank, reversible driving means for driving said belt to agitate workpieces thereon in the tank, means outside said tank actuated by said cleats for automatically reversing said driving means upon predetermined movement in either direction, and means selectively operable for biasing the direction of belt movement for unloading workpieces through passage of cleats through said tank.

5. In a processing machine, a pair of tanks for holdin processing liquid arranged side by side so that workpieces discharged from a first tank are directed into the second tank, a belt extending through each of said tanks along a V-shaped path for supporting workpieces beneath the surface of the liquid and extending around each of said tanks and carrying work agitating means on those portions of the belt normally in the tanks, hold down means in each of said tanks engaging said belts at their upper surface edges for guiding said belts along said path, cleats on said belt normally positioned outside said tank, reversible driving means for driving said belt to agitate workpieces thereon inithe tank, means outside said tank actuated by said cleats for automatiincluding a cathode extending approximately the width of said tank and spaced above said belt at' the apex thereof to contact workpieces thereon, reversible driving means for said pulleys, cleats on said belt normally positioned outside said tank, means outside said tank actuated by said cleats for automatically reversing said driving means upon predetermined movement in either direction, and means selectively operable for causing belt movement in one direction whereby the cleats pass through the bath to carry the workpieces in the tank out over one of the pulleys.

' 7. In an electro-processing machine for handling small workpieces in bulk, a V-shaped tank, pulleys mounted on parallel axes at the ends of said tank, a belt extending over said pulleys and through said tank following the contour thereof and extending around said tank, said belt carrying work agitating means on that portion of the belt normally in the tank including a corrugated upper surface and side parts defining workpiece retaining troughs, electrodes in said tank including a cathode extending across the bottom thereof and spaced above said belt, cleats on said belt extending transverse to the average belt surface which is faced upwardly in the bathand normally positioned outside of said tank, reversible driving means for driving said belt to agitate workpieces thereon and around said cathode, means outside said tank actuated by said cleats for automatically reversing said driving means upon predetermined movement in either direction, means selectively operable to drive said belt continuously in one direction whereby said cleats support workpieces on the belt to move them to a discharge point, and means for preventing slippage between said pulley means and said conveyor belt.

8. In an electro-processing machine, a tank for holding an electrolyte, a belt extending in a V-shaped path through said tank and around said tank and carrying work agitating means on that portion of the belt normally in the tank, electrodes in said tank including a cathode extending across the bottom thereof and spaced above said belt, cleats on said belt extending transverse to the average belt surface which is faced upwardl in the. bath and normally positioned outside of said tank, reversible driving means for driving said belt to agitate workpieces thereon and around said cathode, means outside said tank actuated by said cleats for automatically reversing said driving means upon predetermined movement in either direction, and means selectively operable to drive said belt continuously in one direction whereby said cleats support workpieces on the belt to move them to a discharge point.

9. In an electro-processing machine for handling small workpieces in bulk, a V-shaped tank, pulleys .mounted on parallel axes at the ends of said tank, a belt extending over said pulleys and through said tank following the contour there of and extending around said tank said belt carrying work agitating means on that portion of thebelt normally in the tank including a corrugated upper surface and side parts defining workpiece retaining troughs, electrodes in said tank including a cathode extending across the bottom thereof and spaced above said belt, cleats on said belt extending transverse to the average belt surface which is faced upwardly in the bath and normally positioned outside of said tank, reversible driving meansfor driving said belt to agitate workpieces thereon and around said cath ode, means outside said tank actuated by said cleats for automatically reversing said driving means upon predetermined movement in either 11 direction, and means selectively operable to drive said belt continuously in one direction whereby said cleats support workpieces on the belt to move them to a discharge point.

ALBERT H. HANNON.

REFERENCES CITED The following references are of record in the file 015 this patent:

UNITED STATES PATENTS Number Name Date 393,170 McMurray Nov. 20, 1888 545,429 Lewis Aug. 27, 1895 644,498 Cook Feb. 27, 1900 854,626 Bleisdell -1 May 21, 1907 Number Number 1 P Great Britain 2- of 1895

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