US2738888A

US2738888A - Processing machinery for electroplating and the like

Info

Publication number: US2738888A
Application number: US457255A
Authority: US
Inventors: Todd Guerin; Paul A Hauck
Original assignee: Hanson Van Winkle Munning Co
Current assignee: Hanson Van Winkle Munning Co
Priority date: 1954-09-20
Filing date: 1954-09-20
Publication date: 1956-03-20
Anticipated expiration: 1973-03-20

Description

5 Sneets-Sheet l mm w OO E TT N VN m I II. I HL 0 M U w G. TODD ET AL March 20, 1956 PROCESSING MACHINERY FOR ELECTROPLA'I'ING AND THE LIKE} Filed Sept. 20, 1954 B oi FL W JNM M wt wE 8. emu. mm. \QN, oow i JJ #PPP Ti LT? I w u March 20', 1956 TODD ETAL PROCESSING MACHINERY FOR ELECTROPLATING AND THE LIKE 5 Sneets-Sheet 2 Filed Sept. 20, 1954 W M a U TDK N M W o .L N H C T.

I i A N w w? aw 5 mt L W mm l B 2. I r r H T r March 20, 1956 DD ET AL PROCESSING MACHINERY FOR ELECTROPLATING AND THE LIKE Filed Sept. 20, 1954 5 Sneets-Sheec 5 INVENTORS gUERI N TODD BY A L A. HAUCK ATTORNEYS March 20, 1956 G. TODD ETAL 2,738,888

PROCESSING MACHINERY FOR ELECTROPLATING AND THE LIKE Filed Sept. 20, 1954 5 Sneets-Sheet 4 r PM P -J INVENTORS GUER l N TODD PAUL A. HAUCK FIG- 7 AT TORNEYS March 20, 1956 TODD ETAL PROCESSING MACHINERY FOR ELECTROPLATING AND THE LIKE Filed Sept. 20, 1954 5 Sneecs-Sheet 5 r-L J FIG. 9

FIG. IO

6mm ATTORNE INVENTORS GUERIN TODD PAUL A. HAUCK United States Patent O PROCESSING MACHINERY FOR ELECTRO- PLATING AND THE LIKE Guerin Todd, Shrewsbury, and Paul A. Hauck, Union,

N. J., assignors to Hanson-Van Winkle-Munning Company, Matawan, N. 1., a corporation of New Jersey Application September 20, 1954, Serial No. 457,255 8 Claims. (Cl. 214-89) This invention relates to processing machinery, in which workpieces are automatically transported to successive workstations to undergo different processing treatments in a sequence. More particularly, the invention is concerned with a novel processing machine of the type referred to, in which the workpiece carriers remain at rest at some stations longer than at others and means are provided for moving the carriers in pairs to and from such stations, while the carriers enter and leave the other stations, one at a time. The processing machine of the invention may be used for various purposes, but, since all of the advantages of the invention are realized in its application to electroplating, a form of the new machine for such use will be illustrated and described in detail for purposes of explanation.

Automatic electroplating machines commonly have a plurality of preparation tanks containing solutions, in which the workpieces are immersed for cleaning, rinsing, etching, and like treatments, one or more plating tanks, and a plurality of finishing tanks for re-claim, hot, and cold rinsing, etc. In such machines as usuallyconstructed, the workpiece carriers are advanced along the machine step by step by a conveyer, and an elevator operating in timed relation with the conveyer raises and lowers the carriers, so that they may be moved in raised position over the end of each tank and then lowered to immerse their workpieces in the following tank. Most of the preparation and finishing tanks are of unit size, so that a carrier is advanced from one tank to the next on each step of the conveyer, but a few of the tanks may be of more than unit length, so-that the workpieces are'immersed in the same tank on successive steps in the conveyer movement and the tank thus provides a number of work stations. The plating operation requires a long time compared to any of the preparation or finishing treatments and, accordingly, in some machines, the plating is carried on in tanks of multiple unit size at a station having a plurality of plating positions. When a carrier is lowered to immerse its workpieces in one of the plating tanks, it is advanced in the down position along the tank for a number of conveyer steps before being raised from the tank and lowered into the next one.

The movement of the workpieces through a plating tank without being raised between successive steps of the conveyer movement is satisfactory for the plating of many objects, but some articles have such shapes that they can not be plated properly, if they are moved through the tank during plating. The reason is that, if the anodes are placed to permit movement of the articles between them through the tank, all parts of the articles, because of their shape, will not lie at the same spacing from the anodes and the variation in spacing will be sufiicient to produce a plating varying in thickness. Automobile bumper bars are typical of articles which cannot be satisfactorily plated while being moved through a plating bath and such articles may best be plated in a machine functioning in a skip-stop cycle.

' 2,738,888 Patented Mar. .20, 1956 ICC In a skip-stop machine, the plating is carried on at a number of treatment positions in one or more tanks and, at each position, there is a group of anodes so placed that a carrier may be lowered to immerse its workpieces in the solution in such relation to the anodes that all parts of the workpieces receive an equal plating. The workpiece carriers are delivered to and removed from the treatment positions by a conveyer and an elevator and, in the operation of the machine, the carriers are advanced in groups in the usual way along the preparation tanks and are then delivered singly to successive working positions at the plating station, until all the latter are filled. Thereafter, the carrier in the first working position is removed and delivered to the first finishing tank and a carrier from the last preparation tank is placed in the first working 1 position. The carrier in the second Working position is next removed, delivered to the first finishing tank, and replaced by a carrier from the last preparation tank, and this sequence of operations is continued until the carriers in all the working positions have been removed and replaced, whereupon the cycle is repeated. The carriers delivered to the first of the finishing tanks are moved successively along the tanks of that group and finally reach an unloading station.

In such a skip-stop machine, the overall length of the plating tanks may be so great that, unless the conveyer is run at high speed, time will not be available to vacate a workingposition by transferring the carrier therein to the first finishing tank and filling the vacated position by a carrier from the last preparation tank. Such high speed conveyer movement is objectionable, since a carrier being transported at too high a speed may swing, so that the workpieces are liable to be dropped or injured by contact with parts of the machine.

The present invention is directed to a novel automatic processing machine of the skip-stop type, in which the difi'iculties arising from high speed movement of the workpiece carriers along the plating tanks are avoided. In the new machine, the carriers are moved successively to preparation stations and are then combined into pairs, which are delivered to and removed from the positions in the plating tanks in accordance with a skip-stop cycle. The carriers of the pairs discharged from the plating tanks are then moved successively to finishing tanks, which the carriers enter and leave singly. In the machine, the handling of the carriers in pairs during the plating operation makes it possible to run the conveyer, which delivers the carriers to and removes them from the plating positions, at such a low speed that there is no liability of the carriers swinging and the workpieces thereon being damaged.

For a better understanding of the invention, reference may be made to the accompanying drawings, in which Fig. 1 is a diagrammatic plan view of a machine, which embodies the invention;

Fig. 2 is a diagrammatic elevational view of a portion of the machine including the combining station;

Fig. 3 is a fragmentary plan view of the combining station;

Fig. 4 is an elevational view, with parts broken away, of the combining station;

Fig. 5 is a sectional view on line 5-5 of Fig. 3;

Pg. 6 is a diagrammatic elevational view of a portion of the machine including the separating station;

Fig. 7 is a fragmentary plan view of the separating station;

Fig. 8 is an elevational view, with of the separating station;

Fig. 9 is a sectional view on the line 9-9 of Fig. 3; and

Fig. 10 is a sectional view on the line 10-10 of Fig. 7.

parts broken away,

The machine illustrated comprises a plurality of preparation tanks spaced apart to alford access between their adjacent ends and containing solutions for preliminary treatment of the workpieces, as, for example, cathodic cleansing, rinsing, etching, etc. Most of the tanks are of unit size and have a uniform spacing a (Fig. 1) between their centers, while others, such as tank 21, may be of double size, so as to provide two working positions, indicated at 21a and separated by the spacing a. Beyond the tank 21, the workpiece carriers are delivered to a combining tank 22, which is a preparation tank somewhat longer than twice the length of a single tank 20. Tank 22 is provided with means, by which a pair of workpiece carriers successively delivered to the tank, are moved toward each other to a spacing b, which is less than the spacing a. The pairs of carriers are then raised from tank 22 and delivered to working positions in the plating tanks 23.

Each plating tank 23 has an even number of working positions and can be substantially shorter than the overall length of a group of unit tanks providing the same number of positions. Accordingly, by spacing the positions by the distance b, the total length of the plating tanks can be reduced and the time required to convey the carriers to and from the positions can be correspondingly shortened. The spacing between end positions in adjacent tanks 23 is a distance 0, which is greater than dis tance b to aiford passage between the tanks. The distances b and c have a factor in common.

Beyond the last plating tank, there is a separating tank 24, which receives pairs of the workpiece carriers with a spacing b and is provided with means for delivering the carriers to a conveyer, by which they are advanced at their original spacing a to a succession of unit finishing tanks 25. After leaving the last finishing tank, the carriers may be delivered to an unloading station or transferred to a plant conveyer for delivery to any desired destination. In some machines, the tanks are arranged to form a closed series with the loading and unloading stations close together.

In the machine illustrated, the workpieces W are automobile bumper bars and the workpiece carriers have the form of a rack made up of a top bar 26 and depending arms 27 with supports for two vertical rows of the workpieces. The carriers are transported through the machine on carriages 28 having an axle 29, which has wheels 30 at its opposite ends and is enclosed within a sleeve 31 having a pair of depending hooks 32 for receiving the ends of the top bar of a carrier. The carriers are loaded at a station in front of the series of preparation tanks and the carriages are advanced along the tanks by a conveyor 33 with the wheels of the carriages rolling on the tracks of an elevator 34, which is of conventional construction and may be of the type shown in Curtis Patent 2,626,621. The conveyer comprises pairs of chains having spaced yokes 35 and the yokes in the lower horizontal stretches of the chains engage the axles 29 of the carriages and advance them along the elevator tracks with a step by step movement, each step of which has a length a. At each period of rest in the conveyor movement, the yokes stop the carriages above the centers of single tanks, such as tanks 20, or above treatment positions 21a in the multiple unit tanks. The elevator is timed to operate in the periods of rest of the conveyor and, when the conveyor stops, the elevator moves down with the carriages thereon, so that the workpieces on the carriers depending from the carriages are immersed in the solutions in the tanks. The elevator then uses and the conveyor advances a step.

The conveyer 33 and the elevator 34 extend over a part of the tank 22, which contains a preparation solution, such as a rinse. On opposite sides of the tank 22, the machine frame 36 is provided with longitudinal beams 37, on top of which are mounted a plurality of standards 38 carrying rollers 39. A rail 40 is mounted for movement lengthwise of each beam 37 on the group of rollers of the standards on the beam, and the two rails are connected for longitudinal movement in unison. For this purpose, each rail is formed with a rack 41 on its under side at one end, and the racks are engaged by gears 42 fast on a shaft 43 mounted in fixed bearings. A hydraulic cylinder 44 is mounted on one of the beams 37 and its piston is connected by a rod 45 to a bracket 46 attached to the rail 40 above the beam. The cylinder is of the conventional type and fiuid can be supplied to either end and exhausted from the other by means of a remotely controllable valve. In Fig. 4, the piston rod 45 is shown in its fully extended position and the rail 40 is at the end of its movement toward the right.

Each rail 40 is provided with a plurality of seats 47 formed by pairs of plates and the seats are spaced along the rail a distance d, which is equal to half the distance 11. A weighted dog 48 is pivotally mounted between a pair of standards 49 on the rail to the rear of each seat 47. Outside the path of travel of each rail 40, the frame is provided with a vertical support 50 having a plate 51 at its upper end and the support is disposed below the last position of rest 35a of the yokes 35 in the lower horizontal stretch of the conveyer. Accordingly, when the elevator lowers a carriage from position 35a, the axle 29 of the carriage is deposited on top of the plates 51 of supports 50 on opposite sides of the tank. A plurality of additional supports 52 are mounted on the frame outside each of the rails 40 and each support 52 has a plate 53' at its upper end. The top surface of each plate 53 has a central depression 53a and the bottom of the depression in each plate 53 and the top of each plate 51 are at a slightly higher level than the tops of the seats 47 on rails 40. The support 52 at each side of the tank lying adjacent the support 54) is spaced therefrom a distance, which is less than the distance d, while adjacent supports 52 are separated from another by distance d. The plate at the top of the last support 52 of each group is formed with a stop 54.

The operation of the cylinder 44 is controlled by limit switches, two of which designated LS1 and LS-2 are mounted on one of the beams 37 in position to be operated by the piston rod 45 at opposite ends of its stroke. Other switches LS-S and LS-4 are mounted on

supports

52 and 54 in position to be operated by carriers 28 placed upon the supports by the action of rails 40 and associated parts.

In the operation of the machine, the carriages are moved stepwise along the tracks of elevator 34 by yokes 35 of conveyer 33 and, when a carriage reaches the position 35a and the elevator lowers the carriage, it is deposited on plates 51 on supports 50. At this time, the cylinder 44 has moved the rails 40 to their extreme position at the left and, in such position of the rails, the first seats 47 with their dogs 48 have moved to the left of supports 50. As soon as the carriage has been deposited on supports 50, cylinder 44 causes the rails to move to the right and, as the seats 47 move beneath the axle 29 of the carriage on supports 50, the dogs 48 on rails 40 engage the axle and move it off plates 51 on supports 50 and upon seats 47 to be carried along with the rails. As the rails approach the end of their reciprocation, the seats 47 carrying the axle of the carriage move toward alignment with the first pair of supports 52 and the dogs 48 move the axle 29 upon plates 53 on supports 52, so that it comes to rest in the depressions 53a in the plates. The cylinder 44 is now actuated to move the rails back to the initial position and the carriage remains behind on the first sup ports 52. As the rails move back, the dogs 48 associated with the second pair of seats 47 on the rails move beneath and past the axle 29 on supports 52 and, when the rails are in their extreme position to the left, the second pair of seats 47 lies beneath the axle and the dogs 4?: lie to the rear thereof. The cylinder 44 now makes another stroke and the dogs 48 engage the axle, move it off supports 52 and upon seats 47, and the axle is deposited, as previously described, upon the second pair of supports 52. The

sass-st cylinder then moves the rails 40 to their initial position.

At the proper time, another carriage is moved to the position a of the conveyer and is lowered by the elevator 34 to supports 50. The next stroke of cylinder 44 moving the rails to the right causes the first carriage to be deposited upon the last pair of supports 52 and the second carriage to be transferred from supports to the first pair of supports 52. The two carriages above tank 22 are now spaced a distance b and the pair of carriages are ready for delivery to a pair of adjacent working stations in one of the plating tanks;

The movement of the pairs of carriages with their loaded workpiece carriers from the tank 22 to stations in a plating tank is carried on by a conveyer 55 similar in construction to conveyer 33 and having yokes 56 for engaging the axles of carriages and causing the carriages to roll along the tracks of an elevator 57, which is generally similar to elevator 34. The ends of the tracks of the two elevators lies close together between supports 50 and the adjacent supports 52 and each track of elevator 57 has an end section, which spans the supports 52 and is provided with a lifting member or flipper 58. The flipper is pivoted at 59 andis controllable, so that it can be swung so it will engage the rollers 30 of two carriages on supports 52 or will pass by such rollers. Controllable flippers can be of various constructions and those illustrated (Fig. 9) are of the type disclosed and claimed in our co-pending application Serial No. 457,256, filed September 20, 1954, and now Patent No. 2,710,698.

The flipper illustrated has a counter-weighted arm 60 extending through an opening in the elevator track and provided with a roller 60a at its inner end. The counterweighting tends to swing the flipper to inoperative position against the vertical face of the track and the flipper is moved to operative position by a lever 61 having a cam surface 61a engageable by the roller 60a on the arm 60. Lever 61 is mounted for pivotal movement on a plate 62 attached to the machine frame and it is connected to one end of a toggle 63 having its other end connected to a link 64 pivoted on the plate 62. The joint in the toggle is connected to a rod 65a, which is movable by a solenoid within a housing 65. When the solenoid is de-energized, the rod 64 moves down to shorten the length of the toggle and swing the cam lever 61 counterclockwise, as seen in Fig. 9, so that the cam surface 61a on the lever is out of the range of roller 60a. When theflipper is to be made operable, the solenoid is energized and rod 64 is pulled upward, so that the length of toggle 63 is increased and lever 61 is swung clockwise to place its cam surface 61a in the path of the roller. When the elevator 57 then rises, roller 60a moves along the cam surface and swings the flipper away from the rail of the elevatorand into position to pick up the roller 30 of a carriage.

The conveyer 55 and the elevator 57 are operated by suitable controls, so that, whenever theworkpieces on a pair of carriers on carriages have undergone plating in the working positions of a tank for a suflicient length of time, the elevator raises the carriages and the conveyer delivers them to the separating tank 24. The elevator and conveyer then function to remove a pair of carriages from tank 22 and deliver them to the vacated working stations. The control mechanism causes the elevator and conveyer to function in a cycle, in which the pairs of carriages are removed from the pairs of working stations in the plating tanks successively, so that the workpieces all remain in the plating bath for the same length of time. In order that the elevator may raise the carriages from a pair of working positions in the plating tanks, while leaving the remaining carriages behind, the elevator is provided at each position in a plating tank with a controllable lifting member or flipper, which may be of the type shown in Curtis Patent 2,626,621.

The elevator 57 extends over the major part of tank 24 and the end section of each elevator track is provided with a flipper 66, which is similar in construction to flipper58 and is pivoted on the elevator rail at 67. Flipper 66 has a counter-weighted arm 68, which extends through anopening through the rail and has a roller 69 at its free end, and the flipper also has an arm 70 extending downwardly from its lower end. A roller 71 is mounted on a part of the frame 36 at the lower end of the travel of the elevator and acts on arm 70 to swing the flipper positively to inoperative position. At the upper end of the path of travel of the elevator, a plate 72 is mounted on the frame in position to engage roller 69 and swing the flipper to operative position, so that it will support carriages moved thereon by conveyer 55.

On opposite sides of the tank 24, the machine frame 36 carries longitudinal beams 73 like beams 37 and carrying spaced standards 74 for rollers 75 supporting a. movable rail 76, the construction being similar to that used at tank 22. One of the rails 76 has a bracket 77 connected to the piston rod 78 of a hydraulic cylinder 79 and the rails are provided on their under sides with racks 8t engaged with gears 81 on the shaft 82, so that the rails will move in unison. The cylinder is controlled by limit switches LS-S and LS-6 mounted on one of the beams 73 in position to be operated'by the piston rod78 at opposite ends of its movement and by limit switches LS-7, 15-8, and LS-9 mounted on supports a, 85c, and 852, respectively, in position to be operated by parts of carriages moving on or ofl. the supports.

Each rail carries at its top three

seats

83a, 83b, 83c, each of which is formed of a pair of plates, and a pivoted weighted dog 84 is mounted on the rail at one side of each seat. Outside the path of travel of each rail, the frame is provided with

vertical supports

85a, 85b, 85c, 35d, and 35a. Support 85a is similar to support 50 and the other supports are similar to the supports 52.

Supports

85a and 85d are spaced the distance b and support 85d lies directly beneath a yoke 56a on conveyer 55 at the last position of rest of the yokes in the lower horizontal stretch of the conveyer, while support 85a lies beneath a yoke at 56b. Accordingly, when a pair of carriage 28 is moved along the elevator 57 to the end of the elevator, the down movement of the elevator causes one of the carriages to be deposited on support 85a and the other on support 85d.

An elevator 86 and an associated conveyer 87 extend over part of tank 24 and a yoke 88 on the conveyer at the first position of rest on conveyer 86 lies directly above support 85a The elevator 86 and conveyer 87 extend along the finishing tanks 25 and are of conventional construction.

In the operation of the apparatus, the downward movement of conveyer 57 with carriages at positions of

rest

56a and 56b of the conveyer yokes lowers the carriages, so that they come to rest upon top of

supports

85a and 85d. At this time, the cylinder 79 has moved rails 76 to their extreme positions to the left, as seen in Figs. 7 and 8, and the seats 83a withtheir dogs 84 lie to the left of the carriage on support 85a, while seats 83c with their dogs lie to the left of the carriage on supports 85a. in the first stroke of rails 76 to the right, the carriage on support 85a is transferred to support 85b, while the carriage on support 85d is transferred to support 852. At this time, elevator 86 is in its lower position and, when it rises, it raises the carriage from support 85einto position to be advanced by yokes 88 on conveyer 87. In the next step of movement of the conveyer 87, the carriage is moved over the first finishing tank 25, so that, when the elevator moves down, the workpieces on the carriage are immersed in the solution in tank 25. While this action is going on, the cylinder '79 has continued to reciprocate, so that, on its next movement to the right, the carriage on support 85b is transferred to support 850. The next stroke of the rails to the right then moves the carriage from support 850 to support 85e, where it is picked up by elevator 86 for advanceby conveyer 87 along the finish a sists 7 ing tanks. The spacing of pairs of carriages delivered to tank 24 is thuschang ed by the separating device'including rai1s76 and their associated parts, so that the carriages are delivered to conveyer 87 at the proper intervals and in the proper positions to be engaged by the yokes $8 on conveyer 87 and advanced thereby.

In the machine described, the combining device at tank 22 receives carriages delivered thereto one at a time and advances the carriages to positions, from which pairs of the carriages can be raised by elevator 57 and conveyed to and lowered into adjacent plating positions in the plating tanks. In the combining device, the spacing between the two carriages may be reduced, as is necessary, when the preparation stations are separate tanks with a spacing greater than the spacing between adjacent plating positions. However, the reduction in spacing between carriages effected by the combining device is not essential to skip-stop operation and would not be used in a machine, in which the preparation stations have the same spacing as the plating positions and may be compartments in a single tank. The separating device at tank 24 receives the carriages in pairs from the plating tanks and advances them successively to a position, from which they can be raised by elevator 57 and moved to the finishing stations. The separating device in the machine described increases the spacing between adjacent carriages but this is not essential and is employed, as required, when the spacing between adjacent finishing stations is greater than the spacing of the plating positions.

In some skip-stop machines, the overall length of the plating tanks is not sufficiently great to require an undesirably high conveyer speed for moving the carriages for the workpiece carriers into and out of the plating positions and it is not necessary in such machines to move the carriages to and from the positions in pairs. However, the length of a plating tank with a plurality of plating positions may be substantially less than the overall length of unit tanks providing an equal number of working stations. In that event, the yokes on the conveyer, which delivers the carriage to and removes them from the plating positions, are more closely spaced than the yokes on the conveyer, which advances the carriages along the unit tanks. The finishing tanks beyond the plating tanks may then be of unit size and of the spacing of the preparation tanks, so that the conveyer for moving the carriages along the finishing tanks has yokes at the spacing of the preparation tank conveyer. In such a machine, it is necessary to provide some means for transferring the carriages between adjacent conveyers and adjusting the spacing of the carriages as is required by the spacing on the conveyer, to which the carriages are delivered. The combining and separating devices described may be used for the purpose and whether or not the carriages are handled in pairs or singly during the plating operation is determined by the action of the fiippers on the plating tank elevator.

We claim:

I. In a processing machine, the combination of an elevator raising and lowering workpiece carriers, a conveyer advancing with a stepwise movement carriers supported by the elevator in raised position and spaced apart, the elevator operating in the periods of rest of the conveyer, a second elevator raising and lowering the carriers, a second conveyer, which advances with a stepwise movement carriers supported by the second elevator in raised position and at a spacing different from the spacing, at which they are advanced by the first conveyer, and means receiving the carriers from the first elevator and delivering them to the second elevator at said different spacing, said means including a plurality of a series of spaced supports and reciprocating means for advancing the carriers along the series of supports.

2. In a processing machine, the combination of a con veyer for advancing workpiece carriers stepwise and at a spacing equal to the length of the steps, an elevator operatingto raise and lower the carriers during the periods of rest of the conveyer, the carriers being advanced by the conveyer while supported in raised position by the elevator, combining means removing the carriers from the elevator and forming them into pairs at a spacing less than the original spacing of adjacent carriers being conveyed, a treatment station having working positions in pairs atthe spacingof the pairs of carriers, means including a conveyor and an elevator operating to vacate the pairs of working positions successively by removal of pairs of carriers therefrom and to fill the vacated positions with pairs of carriers removed from the combining means, separating means receiving the pairs of carriers removed from the working positions and discharging them singly,

a third elevator, which receives the carriers singly and at their original spacing from the separating means and operates to raise and lower the separated carriers, and a conveyer advancing with a stepwise lnovement the separated carriers supported in raised position by the third elevator and separated by their original spacing.

3. in a processing machine, the combination of an elevator for raising and lowering workpiece carriers, a conveyer operating to advance with a stepwise movement carriers spaced apart and supported in raised position by the elevator, a support for receiving carriers lowered successively by the elevator at the discharge end of the conveyer, a series of supports beyond the first, the end supports being spaced a less distance than the spacing of the carriers being conveyed, reciprocating means for moving carriers from the first support to those of the series successivcly, a second elevator, which extends along the supports of the series and has controllable means for picking up carriers from the end supports of the series, and a conveyer operating to advance stepwise carriers supported in raised position by the second elevator.

4. In a processing machine, the combination of an elevator for raising and lowering workpiece carriers, a conveyer operating to advance with a stepwise movement carriers spaced apart and supported in raised position by the elevator, a pair of supports for receiving pairs of carriers lowered successively by the elevator at the discharge end of the conveyer, a series of three supports, of which two supports lie between the supports of the pair and one lies beyond the pair of supports, reciprocating means for advancing pairs of carriers on the pair of supports to the supports of the series successively, a second elevator, which raises single carriers successively from the last support in the series, and a conveyer for advancing carriers supported in raised position by the second elevator.

5. In a processing machine having a series of prepara- U011 stations, a treatment station having a plurality of working positions, and a series of finishing stations, the combination of a conveyer and an elevator cooperating to move workpiece carriers into and out of the preparation stations, a second conveyer and a second elevator cooperating to move the carriers into and out of the work ing positions, a third elevator and a third conveyer cooperating to move the carriers into and out of the finishing stations, combining means receiving single carriers successively from the first elevator and delivering them in pairs to the second elevator, and separating means receiving pairs of carriers from the second elevator and delivering them singly to the third elevator.

6. In a processing machine, the combination of a conveyer for advancing workpiece carriers stepwise, an elevator operating to raise and lower the carriers during the periods of rest of the conveyer, the carriers being advanced by the conveyer while supported in raised position by the elevator, at treatment Station having working positions in pairs, combining means removing the carriers singly from the elevator and forming them into pairs for delivery to the pairs of working positions, a second conveyer and a second elevator cooperating to vacate the pairs of working positions successively by removal of pairs of carriers therefrom and to fill the vacated positions with pairs of carriers removed from the combining means, a third elevator for raising and lowering the carriers, separating means receiving the pairs of carriers removed from the working positions, and delivering them singly to the third elevator, and a third conveyor advancing the carriers stepwise while they are supported in elevated position by the third elevator. I

7. In a processing machine, the combination defined in claim 6, in which the combining means removes the carriers from the first elevator, when the latter is in its down position, and the second elevator has controllable lifting means for removing the pairs of carriers from the combining means.

8. In a processing machine, the combination defined in 10 claim 6, in which the separating means receives the pairs of carriers from the second elevator, when the latter is in the down position, and the second elevator has lifting means adjacent the separating means operating to leave a pair of carriers at the separating means, when the elevator I'ZSCS.

References Cited in the file of this patent UNITED STATES PATENTS 2,002,507 Porter May 28, 1935 2,348,112 Da Costa May 2, 1944 2,619,916 Rainier Dec. 2, 1952 2,626,621 Curtis Jan. 27, 1953 2,640,607 De Burgh June 2, 1953 2,671,861 Bullard III Mar. 9, 1954

Claims

1. IN A PROCESSING MACHINE, THE COMBINATION OF AN, ELEVATOR RAISING AND LOWERING WORKPIECE CARRIERS, A CONVEYER ADVANCING WITH A STEPWISE MOVEMENT CARRIERS SUPPORTED BY THE ELEVATOR IN RAISED POSITION AND SPACED APART, THE ELEVATOR OPENING IN THE PERIODS OF REST OF THE CONVEYER, A SECOND ELEVATOR RAISING AND LOWERING THE CARRIERS, A SECOND CONVEYER, WHICH ADVANCES WITH A STEPWISE MOVEMENT CARRIERS SUPPORTED BY THE SECOND ELEVATOR IN RAISED POSITION AND AT A SPACING DIFFERENT FROM THE SPACING, AT WHICH THEY ARE ADVANCED BY THE FIRST CONVEYER, AND MEANS RECEIVING THE CARRIERS FROM THE FIRST ELEVATOR AND DELIVERING THEM TO THE SECOND ELEVATOR AT SAID DIFFERENT SPACING, SAID MEANS INCLUDING A PLURALITY OF A SERIES OF SPACED SUPPORTS AND RECIPROCATING MEANS FOR ADVANCING THE CARRIES ALONG THE SERIES OF SUPPORTS.