US1959764A - Apparatus for plating - Google Patents

Description

May 22, 1934. K T, OTTHOFF K 1,959364 APPARATUS FOR PLAT ING Filed Oct. 19, 1928 I 4 Sheets-Sheet l ffm mgm May 22, l934- K. T. POTTHOFF 1,959,764

APPARATUS FOR PLATING Filed Oct. 19, 1928 4 Sheets-Sheet 2 INVENTOR APPARATUS FOR PLAT ING Filed Oct. 19, 1928 4 Sheets-Sheet 3 INVENTOR ZIWIP@ thin/yf) AAM May 2,2, 1934. K. T. PoTTHoFF n A 1,959,764

APPARATUS FOR PLATING Filed Oct. 19, 1928 4 Sheets-Sheet 4 INVENTOR ZELrZPo ZZzho ("1 BY j) Mll/lfd D l ATTORNEY Patented May 22, 1934 UNITED STATES PATENT OFFICE This invention relates to methods and machines or apparatus for conveying and treating articles and more particularly to plating apparatus and means for conveying carriers for the articles to be plated, though )it is noted that the invention is not limited to plating apparatus nor in some respects to conveying apparatus.

One object of the invention is to pro-vide an improved transfer means for depositing the carrier over a tank and lifting the carrier from the the tank.

Another object of the invention is to provide in an electrolytic apparatus of this kind an improved contact means for making contact with the cathode carrier bar.

Another object of the invention is to provide an apparatus and method of this kind wherein a succession of articles are treated in a succession of tanks for periods of time of the same length, o-r multiples thereof.

Other objects of the invention are to improve generally the simplicity, reliability, economy and efficiency of such methods and apparatus and to provide an apparatus of this kind which is economical, durable and reliable in operation, and economical to manufacture.

Still other objects of the invention will appear as the description proceeds; and while herein details of the invention are described and claimed, the invention is not limited to these, since many and various changes may be made without departing from the scope of the invention as claimed in the broader claims.

The inventive features for the accomplishment of these and other objects'are shown hereinin connection with an improved plating apparatus which, briefly stated, includes a series of tanks including an electric cleaner tank and a, plating tank by the sides of which move conveyor chains carrying pushers on opposite points of the respective chains to move forward conducting carrier bars disposed across the track bars at the sides of the tanks.

Suitable transfer means pick up and transfer the carrier bars from the pusher to over one tank and then to over succeeding tanks and again to the `pusher, intermittent drive means being provided for the chains and transfer means.

A fixed electric contact at the side of the electro-cleaner tank is engageable by the carrier bars as they are deposited at such tank;

and contact pins carried on the bars dip into' carrier bars to the transfer means at'the loading end and to receive carrier bars from the transfer means at the emerging end, the' transfer means being so spaced as to deposit the car` rier bars at points where succeeding transfer means will pick them up, whereby the material is brought to rest for a period at these points, when the intermittent drive may be brought to rest for lengthening the periods.

In the accompanying drawings sho-wing, by way of example, one of many possible embodiments of the invention,

Fig. 1 is a somewhat diagrammatic side elevation of the apparatus;

Fig. 2 is a plan of the apparatus;

Fig. 3 is an end elevation, parts being removed;

Fig. 4 is a fragmental side elevation showing the transfer means in position to pick up a carrier bar; and

Fig. 5 is a fragmental end elevation partly in vertical section of the transfer means.

My improved apparatus is shown herein in combination with a series of tanks adapted for the several different operations of, for instance, chromium plating, and disposed end-for-end in a straight line and including, for instance, a cleaning tank 10 at the loading end 11, an electrocleaning tank 12, a rinsing tank 13, a chromium plating tank 14, a rinse tank 15, and a hot rinse tank 16 at the emerging end 17 of the series. However, the invention is not limited to the number, sequence, length, use, or presence, of the tanks.

Base pedestals 20 arranged along the sides of the series of tanks and near the corners of the apparatus support a horizontal beam 21 disposed on each side of the series of tanks and in turn. supporting upper pedestals 22, 23, 24 mounted on said beams respectively, pedestals 22, 23 being l much taller than pedestals 24. .Tie rods 25 connect the upper ends of opposite taller pedestals.

A drying chamber open at both ends may be disposed above the tanks between the upper part of the taller pedestals as shown in my co-pending application Serial N0. 313,515 filed Oct. 19, 1928, or an end tank 16 may be a drying chamber, though the invention is not limited to the presence or absence of a drying chamber.

Bearing brackets 28 formed on the top faces of the upper corner pedestals 22 support bearing blocks 29 adjustably slidable on said brackets by means of screws 30 and carrying inwardly pointing short shafts 31 mounted in the bearing blocks. Cross-drive shafts 35 (Fig. 3) extending transversely of the machine at the loading and emerging ends and rotatably mounted in the lower ends of the upper corner pedestals 22 carry drive sprockets 36 fast thereon; while Vidle sprockets 37 are loose on said short shafts 31. Endless conveyor chains 38 move in vertical' planes at opposite sides of the apparatus, passing under said drive sprockets 36 and over the other sprockets 37.

Main longitudinal drive shafts 40 rotatably mounted longitudinally of said beams carry, in gear housings 41, worms fast on said main shafts and engaging worm wheels fast on the cross drive shafts.

An intermittent motor 45 is connected by a chain 46 and sprockets 48 to a cross shaft 50 disposed between adjacent tanks and in turn connected by a reducing worm drive 51 to said longitudinal shafts for intermittently driving said longitudinal shafts and consequently the sprockets 36 and conveyor chains 38. 'I'he intermittent motor is controlled by means of a control switch set in operation by a control lever 52 having an end roller 53 engaged by one of the bars 76. The movement of the control lever causes the motor to stop, and timing means associated with the motor causes the motor to start again after the desired period of rest. The motor control means is well known, so need not be described here.

Tracks 60, 61, 62 (Figs. 3 and 5) mounted on the upper pedestals and disposed under the upper and lower horizontal courses 64, 65 and along the outer face of the vertical courses 66 of the chains engage the rollers of the chain and guide said courses.

Pushers or plates 70 (Figs. 1 and 4) of insulating material are connected to opposite links of the respective chains 38 and formed with deep recesses 71 and rearwardly thereof with pusher pins, or shoulders 72 disposed perpendicular to the transverse planesof the courses of the chains in a plane parallel to and near the vertical plane of the chains and pointing upwardly and downwardly in the upper and lower courses respectively. Track bars 74 (Figs. 1, 3 and 5) are arranged near and parallel to, and slightly above the level of the courses 65 at the side edges of the tanks and have depressed end portions 75 (Fig. 1). Conducting carrier bars 76 (Fig. 3) laid across the track bars 74 perpendicular thereto carry hooks 77 adapted to carry material 78 to be plated, and may therefore be termed cathode bars. Said bars 76 clearing said pusher pins at the raised intermediate parts of the track bars 74 and are adapted to be pushed forward by the pusher pins 72 at said depressed end portions 75, and are adapted to be raised by the pins from the bars at the upward course 66 at the emerging end 17 of the series of tanks.

Upper and end tracks 80, 81 (Fig. 1) mounted on the inner face of the upper tall pedestals and adapted to engage the ends of the carrier bars, hold the bars in said recesses 71 as the pusher pins pass up to, over, between, and down from the upper sprockets 37.

Each carrier bar 76 comprises a supporting rod provided at the ends with polygonal contactV shoes 84 (Fig. 5) slidable on one of the track bars 74, and engagement heads 85 on the outer ends of said rods engaged by said pusher pins whereby the carrier bars are pushed along the bus bars. Said heads 85 may, if desired be insulated from the bar 76 or be of insulating material. Means, later to be described are provided for lifting up the carrier bars from over the tanks and transferring them to over succeeding tanks.

Anode bars 88 (Fig. 3) extending longitudinally of the electrolytic tanks between the paths of the hooks 77 carry anodes 89 hung therefrom.

A special pedestal 90 (Figs. 1 and 3) on each .side of the plating tank 14 .and terminating at about the middle level of the tank are each provided with a flanged upper seat 91 in which is received a downwardly tapered mercury switch cup 92 of conducting metal insulated from said seat and filled with mercury 93 to about the level of the liquid in the plating tank. A contact pin 94 near each end of each carrier bar has an upper ,screw eye received on the bar in electrical contact therewith and is adapted when the carrier bar is lowered to dip int-o the mercury and make electrical connection between the cup and the articles to be plated. Suitable current supply means 95 supplies electric current through conductors 96, 97, 98, 99 respectively to the anode bars 88, to the mercury cups 92, to xed contacts 100 on the track bars 74 or to the track bars 74 themselves if they are used as bus bars, and to the cathode bars 101 of the electro-cleaning tank.

The above mentioned means for picking up ,the carrier bar with the material thereon from the pusher pin and transferring it from one tank to the succeeding tank will now be described.

Said means includes an inwardly pointed stationary shaft 105 (Fig. 5) mounted on the upper pedestals 23, 24 on each of which is mounted a spur gear 106 having a projecting hub 107 r0- tatable on said shaft and held in place by a collar 108 fast on the inner end of the stationary shaft.

A pinion 109 engaged by the lower part of the gear 106 is mounted fast on the hub of a sprocket 110 meshing with the conveyor chain 38, whereby the spur gear is rotated in the direction in which the lower course of the conveyor chain travels, as shown by the arrows of Fig. 4.

A transfer arm 112 fast on said hub'107 carries a socket plate 113, which may be of insulating material, pivotally mounted on the outer end of the arm in a plane parallel thereto and having an upwardly open socket recess 114, adapted to receive the head 85, and a lower extension 115 disposed in the plane of the plate and slanting away from the main axis of the plate.

A control bar 117 parallel to the arm is pvoted at the outer end to a pin 118 fast on the free end of said extension 115 and at the inner end to a fixed pin 119 on said collar on a fixed radius of the fixed shaft parallel to said extension.

The distance between pivotal centers of said arm 112 and said bar 117 being equal, and the distance between the pivotal centers of said extension 115 and said radius being equal, whereby said arm, bar and extension are parts of a parallelogram, and said extension is maintained parallel to said radius and said recess 114 is kept pointing upward when the extension is away from its dead center. To keep the recess upward while the extension is on its dead center, I provide parallel links 123, 124 of equalv length pointing in the same direction and mounted fast on said xed pins 118, 119 respectively, the free ends of said links being connected by an auxiliary link bar 125, whereby another parallelogram is formed for controlling the socket plate while on kept with said recess 114 upward.

The pusher pins 72 and the transfer arms 112 are so positioned and said transfer arms, chains and intermittent drive are so timed as to bring the chains to rest when the pusher pins are at the loading end 11 of the apparatus to give good time for loading carrier bars, and to bring the pusher pins to positions ready to give up carrier bars to transfer means adapted to pick them up at the lits les

.140 .said dead center, whereby the socket is always A loading end 11, and to bring the pusher pins to positions to receive carrier bars from transfer means ready to deposit them at the emerging end 17.

The transfer arms are so spaced relative to each other that a carrier bar 76 deposited upon the higher part of the track bar 74 or on said fixed contact 100 by one pair of arms 112 is in position to be picked up by the succeeding pair of arms.

The transfer arms 112 are synchronized to pick up carrier bars all at the same time, whereby the arms are all parallel, and one pair passes through about a third of a revolution before picking up the bar deposited by the preceding pair, whereby the material is left in each tank an equal period of time or multiple thereof, as in the long tank 15, the solutions being made of a strength respectively to accord with said periods and have the required amount of action within said periods. All of these periods may be lengthened to any desired extent by havingthe intermittent drive to bring the arms to rest after a carrier bar is deposited but before thebar is again picked up. The period for any individual tank may be lengthened a multiple of the minimum period by making the tank longer and having additional sets of transfer arms, as at the tank 15.

This method of subjecting the articles tol equal periods of treatment is a very efficient and orderly method, economizing time, space and supervision, even if done entirely by hand, and it permits transferring a succession of groups of articles successively through a succession of tanks including a plating tank and the like, the groups of articles being left in each of certain of the tanks equal lengths of time, and in other tanks a multiple thereof, which can be performed with relatively unskilled labor, so long as the solutions in the tanks are kept at predetermined strength respectively to accord with said periods respectively.

The operation of the apparatus is simple, and obvious from the foregoing. The carrier bars 76 remain with the pushers except when over the raised portions of the track bar 74. The intermittent drive brings the pushers and carrier bars to rest well above the tank 10 at the loading end 1l where plated articles which have come down the course 66 are unloaded and new articles to be plated are loaded on the carrier bars, al1 by a single operator if desired.

On the next movement of the conveyor, the articles are lowered into the cleaning tank 10 and there brought to rest during the period of rest and until picked up as the transfer arm at that tank moves upward on the next movement of the conveyor.

On said next movement, the carrier bar will be picked up by the transfer arms and the articles transferred to the electro-cleaning tank 12, the carrier bar resting on and engaging the contact 100 to subject the articles to the electro-cleaning process.

On the next movement of the articles are brought to rest for a period in the tank 13, the carrier bar resting on the track bar 74, and are then transferred to the plating tank, the contact pin 94 being long enough to make full electrical contact with the mercury as the articles are lowered. The intermittent drive then brings the articles to rest, thus submitting all parts of the article to the bath, thus particularly adapting the apparatus to chromium plating.

On the next cycle of movement, the articles are transferred to, and brought to rest in, the tank 15, and if this or any of the other tanks be made long enough to provide more than one pair of transfer arms and more than one station of rest the articles are subjected to more than one period of treatment.

The articles are next transferred to, and brought to rest in, the last tank 16. The carrier bar, instead of being held away from the pushers 70 by resting on the track bar 74 as at tanks 12, 13, 14 and 15 are lowered over the depressed portion of the track bar directly into the recess 71 of the pusher, which is located and timed to receive it.

On succeeding movements of the conveyor chain, the carrier bars will be carried up the course 66, at the end 17, along the course 60 and then again down the course 66 at the end 11, where they are brought to rest for unloading, after which the above operation is repeated.

The mercury switch has an important advantage in that it always gives the same electrical contact without regard to the weight of the material treated.

Advantages obtained by the herein shown conveyor drive are as follows:

It facilitates loading and unloading.

It holds the material stationary in the tanks and relative to the anodes and thus intensifies action of the solution when material is stationary, and disposed successive racks of material in the same relation to the anodes, thus particularly adapting the apparatus to chromium plating.

It intensifies washing motion, since it necessit tates moving the material faster into and from the bath in order to have the material remain in solution for same period of time.

The intermittent drive permits the reduction of size of various tanks in some instances as much as 50%, with consequent saving in cost of equipment, floor space and the like.

It may be arranged to permit thorough draining of solution, thereby eliminating consequent contamination of the succeeding baths.

In plating machines it removes gases formed on the articles caused by plating action, more thoroughly since it will be necessary for the material to move into or from the bath faster than without intermittent motion.

The intermittent motion will tend to alter character of the deposit with a tendency toward reducing porosity of coating; in other words, it gives more of a cross-graining eiect on the deposit.

While herein, in the specification and claims I mention tanks in which the articles are immersed rather than spraying or treating stations or zones where the articles may be sprayed or otherwise treated, it is understood that such stations may sometimes be substituted for tanks, and the claims herein are to be, for purposes of protection, construed as covering such treating stations when such substitution is possible.

I claim as my invention:

1. A transfer means comprising a pair of alined stationary members; a transfer arm revoluble on each member; a socket member pivotally mounted on the arm and having an upwardly open socket recess; and members pivoted to offset points on said socket plate and stationary member, whereed on the outer end of the arm and having an upwardly opensocket recess off-set pins fast on the socket plate; a pair of control bars parallel and equal in length to the arm and respectively pivoted to said offset pins and stationary shaft, whereby said recess is kept pointing upward.

3. An apparatus comprising; conveyor chains; a fixed shaft near each chain; a spur gear having a projecting hub rotatable on said shaft; a collar fast on the end of the shaft and holding the gear in place; a pinion engaged by the lower part of the gear and provided with a sprocket fast on the side thereof and engaging the chain, whereby the spur gear is rotated in the direction in which the chain travels; a radial transfer arm fast on said hub; a socket plate pivoted thereon and having an upwardly open recess, and means whereby said recess is kept pointing upward.

4. An apparatus comprising a frame comprising members arranged along the sides of the apparatus and including upper pedestals at the corners of the apparatus; bearing brackets formed on the top faces of the upper corner pedestals; bearing blocks adjustably slidable on said brackets; inwardly pointing short shafts mounted in the bearing blocks; cross-drive shafts across the frame at both ends; drive sprockets fast on the drive shafts and idle sprockets loose on the short shafts; conveyor chains at opposite sides of the apparatus passing under said drive sprockets and over the other sprockets; pushers connected to opposite links of the respective chains; and carrier bars disposed across the apparatus and moved forward by the pushers.

5. An apparatus comprising a tank; a carrier disposed over the tank, and adapted to immerse articles in liquid in the tank; means for lifting the carrier up from the tank and lowering it toward the tank; a deep mercury cup; and a pending contact on the carrier long enough to reach the mercury before the article reaches the liquid; the cup being deep enough to receive the contact at the lowest position of the carrier.

6. An apparatus comprising a tank; chains at opposite sides of the tank carrying pushers having upwardly opening recesses; fixed supports at opposite sides of the tanks above the level of the course of the pushers; transverse carrier bars received in said recesses; and transfer means for transferring the carrier bars from and to the pushers, while upwardly open, to and from the top of said supports.

7. A transfer means comprising a stationary member; a transfer arm revoluble on said member; a pivoted member pivotally mounted on said arm and carrying thereon a member having an upwardly open recess; and two stiff links. connecting different offset eccentric points on said pivoted member to corresponding points on the stationary member for maintaining said recess upwardly opening position.

8. An apparatus comprising a series of tanks; conveyor chains and track bars at both sides of the tanks; pushers on opposite points of the respective chains; carrier bars across the track bars moved forward by the pushers; transfer means for picking up and transferring carrier bars from over one tank to over another tank; the transfer means being so positioned and timed that the respective transfer means will deposit and pick up the same carrier at the same location of the carrier on the track bar; said track bars being elevated except near the ends to hold the carrier bar out of reach of the pushers.

9. An apparatus comprising a tank for liquid; means for lowering and immersing articles in the liquid and lifting them from the liquid; and means for electrically charging the articles the major part of the time they are being lowered and raised in the liquid, said means being entirely exterior to the liquid after the article is removed.

10. An apparatus comprising a tank; means to immerse articles in liquid in the tank and to lift the articles from the liquid; and means including interengageable contacts disposed to one side of the tank and constructed to automatically engage during the major part of the time the articles are being raised and lowered in the liquid.

11. An apparatus comprising a tank for liquid; non-magnetic supporting means for lowering articles into the liquid and lifting them from the liquid; and means for electrically charging the articles the major part of the time they are being lifted and lowered in the liquid.

12i An apparatus comprising a tank; an electrically conducting carrier adapted to immerse articles in liquid in the tank; means insulated from the carrier for lifting the carrier up from, and lowering it toward, the liquid to immerse the articles therein; and means for electrically charging the carrier the major portion of the time the articles are being raised and lowered in the liquid.

KURT T. POTTHOFF.

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