US2887210A

US2887210A - Plating apparatus

Info

Publication number: US2887210A
Application number: US620505A
Authority: US
Inventors: Borodin Daniel
Original assignee: Allied Res Products Inc
Current assignee: Allied Res Products Inc
Priority date: 1956-11-05
Filing date: 1956-11-05
Publication date: 1959-05-19
Anticipated expiration: 1976-05-19

Description

May 19, 1959 D. J. BORODIN PLATING APPARATUS Filed Nov. 5, 1956 5 Sheets-Sheet 1 INVENTOR.

V j, do/Poom A rroAm f d May 19, 1959 D. J. BORODIN 2,837,210

PLATING APPARATUS Filed Nov. 5, 1956 I 5 SheeAs-Sheet 2 NA ii May 19, 1959 D. J. BORODIN PLATING APPARATUS 5 Sheets-Sheet 3 Filed NOV. 5, 1956 INVENTOR.

Dfi/Y/il ,d. BOROO/A BY ATTO/FA/[VJ May 19, 1 D. J. BORODIN PLATING APPARATUS 5 Sheets-Sheet 4 Filed Nov. 5, 1956 INVENTOR.

Ofl/V/[Z d. EOROU/A M F M May 19, 1959 D. J. BORODIN PLATING APPARATUS -5 Sheets-Sheet 5 INVENTOR.

J. eciwoo/w' 1 Filed Nov. 5, 1956 United States Patent PLATIN G APPARATUS Daniel Borodin, Detroit, Mich., assignor, by mesne assignments, to Allied Research Products, Incorporated, Baltimore, Md., a corporation of Maryland Application November 5, 1956, Serial No. 620,505 12 Claims. (Cl. 198-19) The present invention relates particularly to an improvement in the type of plating machine shown and described in my copending application Serial No. 596,712, filed July 9, 1956. In said application, there is showna plating apparatus which includes a plurality of successively positioned plating tanks and a carriage mounted to reciprocate along one side of the tanks. The carriage has pusher elements mounted thereon for engaging and moving rail supported work carriers along the individual tanks and withflelevators adapted for lifting the work carriers adjacent the end of one tank and depositing them on the rail above the next adjacent tank. In a single-station tank, the time of complete immersion of the work pieces in the tank amounts to the time that it takes for the carriage to travel through its retraction stroke. In some plating operations, the nature of the treating solution is such that the time of immersion of the work pieces in the solution in a single-station tank is preferably less than the time required for the carriage to travel its return stroke and means must be provided for controlling the immersion time to a period less than the time required for the carriage to travel through its retraction stroke. Likewise, in a multiple station tank, it is sometimes desirable to have an immersion time which isless than the maximum time that'the work is permitted to remain in the tank by reason of the cycling of the carriage.

It is an object of the present invention to provide a means whereby the time of immersion of the work pieces inatank can be controlled independently of the stroke of the carriage.

A further object of the invention resides in the provision of means cooperating with 'the carriage and arranged to delay. the immersion of the work pieces in a plating tank so. that the period of immersion can be accurately controlled within an adjustable range.

Another object of. the invention resides in the provision of a mechanism for delaying the set-down of work carriers which is constructed such that its operation does not have to be synchronized with the operation of the carriage and elevators.

In the drawings:

Fig. 1 is a fragmentary perspective view, generally schematic, of a plating apparatus embodying the present invention. i i

Fig. 2 is a transverse sectional view of the apparatus with parts broken away.

Fig. 3 is a fragmentary side elevational view of the apparatus.

Fig. 4 is a sectional view taken along the lines 44 iBFiEJZ' i ice Fig. 5 is a sectional view taken along the lines 5-5 in Fig. 2.

Fig. 6 is a fragmentary side elevation partly in section of the structure shown in Fig. 5.

Fig. 7 is a fragmentary perspective view of a portion of the apparatus.

Fig. 8 is a fragmentary side elevational view partly in section of another portion of the apparatus.

Fig. 9 is a diagrammatic showing of the hydraulic circuit of the apparatus.

Referring to Figs. 1 and 2, there is illustrated a series of plating tanks, two of which are designated 10 and 12, respectively. The tanks 10 and 12 are supported on a base 14. There is also supported on base 14 as by rollers 16 a carriage 18. A upright panel 20 is mounted on base 14 between the row of tanks and carriage 18. At pro-selected stations on carriage 18, there are arranged elevators 22. The arrangement thus far described is substantially the same as that disclosed in my copending application Serial No. 596,712; and, as disclosed in said application, means are provided for reciprocating carriage 18 longitudinally of the row of plating tanks and means are also provided for raising and lowering elevators 22 in timed relation to the stroke of carriage 18.

In the arrangement shown herein, each elevator 22 ineludes an upright column 24 fashioned with a gear rack 26 that is engaged by a gear 28 on a horizontally extending shaft 30. The drive means for shaft 30 are not illustrated. Each column 24 is provided at its upper end with an arm 32 extending laterally over the plating tanks. The arms 32 of a pair of adjacent elevators are interconnected by a frame 34 supported on boom portions 36 at the free ends of arms 32. Frame 34 includes an upper longitudinal member 38 anda pair of lower longitudinally extending members 40 which are held together by cross pieces 42 and vertical struts 44. Lift angles 46 in the form of structural angle members are secured to the inner sides of the lower longitudinally extending members 40.

Referring now particularly to Fig. 2, the workpieces W are supported from work carriers 48 which are fashioned with a pair of outwardly extending flanges 50 ar ranged to be engaged by the lift angles 46 for elevating the Work pieces when the elevators 22 are raised. A pair of spaced apart work rails 52 are insulatively mounted of the tanks as by brackets 54, and carriers 48 are fashioned with shoes 56 which slidably support the carriers 48 on the upper edges of rails .52 when the carriers are in the lowered position. The plating anodes 58 are supported on bus bars 60, the plating circuit of the bus bars 60 and rails 52 being completed through the work pieces W and the plating solution in the tank. In the case of a tank Where a plating operation is not performed, no anodes would be placed in the tank.

With the arrangement thus far described, the operationof transferring the work pieces W from the tank 10 to the tank 12 is the same as the operation disclosed in my said copending application Serial No. 596,712. A work piece W supported on a carrier 48 in tank 10 as indicated by broken lines 49 in Fig. 1 is elevated when elevators 22 are raised and then moved horizontally to the right as viewed in Figs. 1 and 3 as carriage 18 advances through its forward stroke to a position over tank 12. Thereafter, when the elevators are lowered, the work pieces are deposited in tank 12 at the position indicated by broken lines 51 in Fig. 1. The carriage 18 then moves through its retraction stroke, that is, to the left as viewed in Figs.

1 and 3, back to the position shown in Fig. 1. Then, on

the next cycle of the machine, the carrier 48 at the position indicated at 51 over tank 12 will be picked up by lift angles 46 and deposited in the next successive tank.

As pointed out previously, it is often desirable to maintain the Work pieces immersed in a tank for a period of time less than the period of time elapsing during the retraction stroke of' the carriage. The present invention is directed specifically to a provision of means for delaying the set-down of the work in tank 12 so that this time of immersion in tank'1'2 can be varied from the full dwell time to a-period approaching-zero immersion of actually zero; that is, skipping a station altogether. The means for providing this delayed set-down comprises the mechanism designated generally by numeral 62'. This mechanism includes a pair of upright channels '64 secured to the outer side of the wall of tank 12 as by brackets 65 and provided-with vertical guide bars 66. At their upper ends, channels 64 are interconnected by a brace 67'; and intermediate their upper andlower ends, channels 64 are interconnected by a yoke 68. A' hydraulic cylinder 70 is. supported on yoke 68 as trunriions 72. The rod 74- connected to the piston withinzcylinder 70vprojjects downwardly through the lower end of cylinder 70. The lower free end ofrod '74- projects fi'eel'y through a bushing, 76 and is adjustably retained thereon by a nut-78'threaded on the lower end of rod. 74. Bushing 76 is supported on a lower shoe 80' having. pairs of rollers 82 at opposite sides thereof which engage guide bars 66. Shoe 80 is rigidly secured to the lower end of a column. 84. To the upper end of column 84, there is secured an arm 86 which extends laterally over tank 12. A second shoe 88 provided with similar guide rollers 82 is mounted at the upper end of column 84 so that the column 84 together with its laterally extending arm 86 is guided by the four sets of rollers 82 for movement vertically along guide bars 66.

Arm 86 is provided with a depending leg 90 on which aremount'edlift angles 92'. Lift angles 92 are disposed centrally between lift angles 46 on elevators 22 and the carriers 48' are fashioned with inwardly projecting flanges 94Which are arranged to be engaged by the inside lift angles 92. At its outer free end, arm 86 has bolted thereon a plate 96 on which a roller 98 is journalled. Plate 96 is adjustable vertically on arm 86 as by bolts 97 in slots 99'. Roller 98 is aligned vertically with a guide bar ,100 mounted on the inside lift angle 46 on elevators 22.

I The uppermost position of column 84 is limited by vertically adjustable stops 102 which engage upper shoe 88', and the lowermost position of column 84 is limited by vertically adjustable stops 104 which engage the lower end of column 84. At the same time, vertical adjustment is provided between the lower end of piston rod 74 and shoe 80. To provide this latter adjustment, bushing 78 is externally threaded as at 106 for engagement with a nut 108 fixedly mounted on shoe 80 (Fig. 6). 110 is provided for locking bushing 78 in. its adjusted position.

Referring now to Fig. 9, it will be observed that the upperandlower ends of cylinder 70 have conduits 112 and 114, respectively, leading thereto. These conduits are connected with a four-way valve 116 that is operated by a pair of solenoids 118 and 119. Solenoid 1'18 is energized through a timer 120 and solenoid 119 is energized through a circuit which includes a limit switch 121. Solenoid 119 when energized shifts the spool of valve 122 so that oil under pressure is admitted to the lower end of cylinder 70 to thereby raise piston rod 74. Limit switch 121 is located so as to be actuated and close the circuit through solenoid 119 shortly after elevator 22 starts moving in an upward direction. Timer 120 is arranged to receive a signal by means of suitable limit switches or thelike when the elevator 22 starts lowering from the elevated position. Timer 120 .is arranged tobe manually adjusted to vary the period of delay for energizing solenoid 118 and thereby delay the operation of valve 116 and the admission of oil under pressure to the upper end of cylinder 70. Valve 116 connects by means of

conduits

122 and 124 in a circuit which includes a pump 126 and a reservoir 128. Flow control valves 130 and 132 are arranged in conduits 112 and 114 to control the velocity I A lock nut of flow of the oil from the opposite ends of the cylinder 70.

When the elevators 22 and the column 84 are in the lowered position, the carrier 48 rests upon the rails 52 as is illustrated in Fig. 2. In this position, the outside lift angles 46 on elevators 22 have a clearance a with flanges 50' of carrier 48 and the stops 104 are adjusted so that the inside lift angles 92 have a clearance b with the flanges 94 of carriers 48. The adjustment of stops 104 at the lower end of column 84 is preferably such that the clearance b is substantially equal to the clearance c between roller 98 and the guide rail on the inner lift angle 46 on elevators 22. This adjustment is .made with the carriage 18 at the forward end of its stroke and with the elevators 22 and the column 84 in their lowermost positions.

In operation, assuming that a carrier 48 is located on rails 52 above tank 10 in the position indicated by broken lines 49 in Fig. 1 and the cycle of the machine is initiated, elevators 22 raise frame 34 to the broken line position indicated in Fig. 3. However, as soon as the lift angles 46 have moved upwardly through the clearance distance a, the flanges 50 of the carrier 48 are engaged by lift angles 46 and the carrier is elevated. If the clearance a is substantially equal to the clearance c, then when lift angles 46 engage the flanges 50, guide bar 100 at its for ward end engages roller 98 so that the arm 86 and its column 84 are also lifted by the elevators 22-. Rather than trying to obtain accurate synchronization of the retraction of piston rod 74 with the raising of elevators 22, the admission of oil under pressure to the lower end of cylinder 70 is delayed slightly by means of limit switch 121 so that the bushing 76 merely slides upwardly on piston rod 74 when the lift angles 46 are elevated. Or,

if preferred, solenoid 119 could be energized at the same instant that the lift angles 46 are elevated and flow control valve 130 adjusted so that the movement of rod 74 upwardly will be at a slower rate than the upward movement of lift angles 46.

When the elevators 22 reach the upper end of their stroke, carriage 18 starts moving forwardly with roller 98 still engaging rail 100 and rolling thereon. At this time, piston rod 74 may have partially retracted so that the lower end may be raised to about the position shown in broken lines for the nut 78 in Fig. 2. Carrier 48 is thus moved horizontally to a position over tank 12 where the inside lift angles 92 underlie the flanges 94 of carrier 98. In this connection, it will be observed that if the clearances a, b and c are substantially all the same, the clearance b will be maintained in the elevated position of lift angles 46; and'alignment of'the lift angles 92 in the proper horizontal plane relative to the plane of flanges 94 of the carrier is thus insured.

As mentioned above, the operation of hydraulic cylinder 70 is such that the upwardtravel of piston rod 74 lags the upward movement of elevators 22. However, the

timing is such that by the time 'the'carriage 18 reaches the forward end of its stroke, piston rod 74 is fully retracted and the nuts 78- engage the bushing 76. The upper stops 102 are adjusted such that the upper shoe 88 on column 84 engages these stops when the elevator columns 24 are at the upper end of their stroke. Bushing 76 is adjusted with reference to lower shoe 80 so that the lower end of piston rod 74 engages bushing 76 when the piston within cylinder 70 approaches the endof its upward stroke. Thus, the built-in cushioning effect in cylinder 70 inctained; and at the same time, the roller 98 isnot liftedotf guide rail 108 when the piston rod is fully retracted- After the carriage reaches the forward end of its stroke,

elevators 22 are arranged to automatically lower lift angles 46 and thus deposit carrier 48 on the lift angles 92. Thus, the carrier 48 and the work pieces W supported thereby are retained in an elevated position, even though the elevators are lowered. When the lift angles 46 starttolower, a signalis received by'timer 120. Then, after the time delay for which timer is set has elapsed,

solenoid 118 is automatically actuated to admit oilto the upper end of cylinder 70 and permit discharge of oil from the lower end of cylinder 70 at a rate controlled by the setting of valve 132. When this occurs, column 84 with its arm 86 is permitted to gravitate downwardly and thus lower the work pieces into tank 12 to a position wherein the carrier 48 is again supported on rails 52 and out of engagement with lift angles 46 and 92; that is, to the position indicated in Fig. 2. Carriage 18 then retracts to the position shown in Fig. l; and on the next cycle, lift angles 46 will engage flanges 50 of carrier 48 at the position indicated at 51in Fig; 1 and transfer the carrier 48 to the next successive tank. n Thus, it will be seen that I have provided a relatively simple mechanism for delaying the set-down of the work carrier in a plating tank so as to vary as desired the time of immersion of the Work pieces in a particular tank. Furthermore, it will be observed that by the. connection between the column 84 and the piston rod 74 which enables the column to move upwardly independently of the piston rod, I have eliminated the problem of synchronizing the movement of the elevators with the actuation of piston rod 74 which would exist if the piston rod 74 were rigidly connected to the column 84.

I claim:

1. In a conveying mechanism of the type including a rail, a work carrier supported on said rail and a transfer mechanism for lifting the carrier at a first station along the rail, moving the carrier longitudinally of the rail in an elevated position and then lowering the carrier onto said rail at a second station along the rail, means for controlling the lowering of said carrier at said second station independently of said transfer mechanism comprising a vertically movable upright support at said second station, said transfer mechanism including a vertically movable element, a one-way driving connection between said vertically movable element and saidupright support arranged to elevate said upright support when said vertically movable element is raised, means for raising and lowering said upright support, a one-way driving connection between said raising and lowering means and said upright support operative to elevate said upright support when said raising and lowering means are actuated, means on said upright support positioned to receive a work carrier from said transfer mechanism when the transfer mechanism is lowered at said second station and means for operating said raising and lowering means in a predetermined timed relation to the operation of said transfer mechanism, said raising and lowering means comprising a hydraulic piston cylinder assembly having a vertically disposed retractable piston rod, said second mentioned one-way driving connection comprising means interconnecting said piston rod and said upright support such that the upright support is elevated by the piston rod when the piston rod is actuated in one direction and the upright support is free to move upwardly independently of the piston rod in response to upward movement of said verticallymovable element.

2. The combination set forth in claim 1 wherein said piston rod projects vertically downwardly from the lower end of said cylinder, said upright support having a bracket thereon through a portion of which the piston rod projects, said piston rod having an abutment thereon below said bracket and arranged to engage said portion of the bracket to lift said upright support when the piston rod is retracted.

3. The combination set forth in claim 2 including vertically adjustable stops for limiting the uppermost and lowermost positions of said upright support.

4. The combination set forth in claim 3 wherein said portion of the bracket comprises a bushing through which the piston rod projects, said bushing being vertically adjustable relative to said upright support to vary the effective stroke of the piston rod.

5. In a conveying mechanism, the combination comprising a horizontally extending rail adapted to support a work canwier, a work carrier on said rail, a transfer mechanism for lifting the Work carrier from the rail at a first station, movingthe carrier in an elevated position along the rail and then lowering the work carrier onto the rail at said second station, said transfer mechanism including a pair of lift members adapted to engage said workoarrier, said lift members extending longitudinally of the rail and spaced transversely thereof, means for raising and lowering said lift members and for reciprocating said lift members longitudinally of the rail and means for lowering the work carrier 'at said second sta-. tion independently of said transfer mechanism comprising a vertically movable upright support at said second station, meansoperative to interconnect at least one of said lift members and said upright support such that the upright support is elevated in response to vertical movement of said lift members, a raising and lowering means for said uprightsupport, a one-way driving connectionbetween said raising and lowering means and said up rightsupport operative to elevate the upright support when the raising and lowering,means are actuated, a pair of 'lift members on said upright support positioned to receive a work carrier from the lift members on said transfer mechanism when the transfer mechanism is lowered at said second station and means for operating said raising and lowering means in a predetermined timed relation to the operation of said transfer mechanism, said work carrier being provided with a pair of flanges at opposite ends thereof adapted to be engaged by said lift members on the transfer mechanism and wherein said work carrier is provided with a second pair of flanges intermediate its ends and engageable with the lift members on said upright support.

6. The combination set forth in claim 5 wherein said means operative to interconnect said upright support with at least one of said lift members comprises an abutment on said upright support, an abutment on one of said lift members disposed vertically below said upright support and means for adjusting the lowermost position of said upright support such that when said work carrier is supported on said rail, said abutments are spaced vertically apart.

7. The combination set forth in claim 6 wherein said abutment on said upright support is disposed relative to the lift members on said upright support such that in the lowermost position of said upright support, said last mentioned lift members are in a plane spaced below the second mentioned flanges on the work carrier on said rail.

8. The combination set forth in claim 7 wherein said rail is disposed such that when said lift members on said transfer mechanism are disposed in their lowermost position, said first mentioned flanges on said work carriers are in a plane spaced above said lift members on said transfer mechanism.

9. The combination set forth in claim 8 including means for limiting the uppermost position of said upright support for maintaining said abutments in interengagement when said upright support is raised to its uppermost position.

10. In a plating machine of the type having a carriage movable longitudinally along successively arranged plating tanks to move rail supported work carriers through a succession of stations in the tanks in response to longitudinal movement of the carriage and having a vertically movable elevator structure thereon and movable therewith, said elevator structure having lift members thereon for bodily lifting the carriers oif the rails adjacent the end of one tank and carrying them horizontally in an elevated position to a station above a second tank, means for controlling the lowering of the carriers into the second tank comprising an upright support positioned alongside the second tank, a work carrier support movable vertically on said upright support and extending laterally over the tank and overlyinga portion of said elevator structure so that when the elevator structure is raised from a lowered position, the carrier support is engaged by the elevator structure and moved upwardly onsaid upright support to an elevated position; means interposed between said carrier support and said portion of the elevator structure for permitting the lift members to-move freely in a horizontal plane relative to said carrier support in response to longitudinal movement of the carriage, a raising and lowering means on said support including a vertically movable element, said carrier support being mounted on said upright support for movementvertically relative'to said element, said element having an abutment thereon engageable with the carrier support when the element is moved upwardly to raise the carrier support and supportit inv said elevated position and means for operating said raising andloweriug means in timed rela tion to the reciprocation ofthe carriage and the vertical. movement of the elevator structure so that the lowering of the carrier support from said elevated position may be delayed relative to the lowering of the elevator structure.

11'. The combination called for in claim 10 wherein said portion of said elevator structure comprises a pair of lift membersen'gageable with" the carriers to raise-and support the: same in: an elevated position inresponse to vertical upward: movement of the elevator structure.

12. The combination" called for in' claim 10 wherein the raising. and lowering means'co'mprises a piston cylinder assembly and said element comprises a downwardlyextendingpist'on. rod connected with said piston cylinder assembly, said abutment being mounted adjacent the lower end of said piston rod, said carrier support having an opening therethrough through which the piston rod extends and by means of which the carrier support is' slidably mounted on the rod, said abutment being disposed so as to engage with the underside ofsaid. carrier support to lift the carrier'support when the piston rod is retracted.

References Cited in the file'of" this patent UNITED STATES PATENTS 2,245,673 Huenerfauth June 17, 1941 2,518,034 Ludwig Aug. 8', 1-950 2,591,681 Davis- Apr. 8, 1952