US2851044A

US2851044A - Plating machine

Info

Publication number: US2851044A
Application number: US531194A
Authority: US
Inventors: John V Davis
Original assignee: Udylite Corp
Current assignee: Udylite Corp
Priority date: 1955-08-29
Filing date: 1955-08-29
Publication date: 1958-09-09
Anticipated expiration: 1975-09-09

Description

Sept. 9, 1958 J. v. DAVIS PLATING MACHINE 3 Sheets-Sheet 1 Filed Aug. 29, 1955 INVENTOR. J22?! 1 flax 715'.

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fiZ w 1 fizz/2J5 TOFIVI/S Sept. 9, 1958 J. v. DAVIS PLATING MACHINE 3 Sheets-Sheet 3 Filed Aug. 29, 1955 R m W H $9 Pu MY aFNB/g United States Patent PLATING MACHINE John V. Davis, Grosse Pointe Farms, Mich.,' assignor to The Udylite Corporation, Detroit, Mich., a corporation of Delaware Application August 29, 1955, Serial No. 531,194 14 Claims. (01. 134-76 This invention relates to machines for plating and chemically coating materials.

The principles of the invention, while generally applicable to any type of fully or semi-automatic machine, are representatively embodied in a plating machine of the straight-line type.

In a common form of plating machine of that type, a plurality of workpieces is mounted upon each of a plurality of racks, and means are provided for so serially transporting the racks as to immerse the workpieces in each of a series of aligned tanks containing the diverse cleaning and plating solutions. A tank may be sufficiently long to accept a plurality of spaced, serially aligned Workcarrying racks at one time. In that case, the tank may be considered to comprise a number of cells equal to the number of such racks. Under certain conditions, the several cells may be physically defined in the tank by 2. advancing of the racks can be accomplished only when the racks are emersed and raised sufliciently to clear the solution, anodes, partitions or tank walls.

As one practical method of advancing the racks, and hence the workpieces, in a horizontal sense, either in a lower, immersed position, or in an upper, emersed position, each rack may be mounted upon an individual wheelequipped carrier. The carrier wheels are adapted to ride upon a track which overlies the line of tanks and which comprises a single rail or, as disclosed herein, a pair of rails mounted in spaced parallelism, at least one wheel on each carrier being engageable with each rail. For present partitions, or by the provision, at each cell location, of i an anode nest approximately conformed to the shape of the workpieces mounted on the rack.

If a tank includes a plurality of undivided cells, the racks may be translated the length of the tank while the workpieces remain immersed. Alternatively, the racks may be advanced through the tank by a series of successive immersions, being lowered into the tank, raised, advanced one cell space along the tank while emersed, lowered, and so forth. Where the tank is physically partitioned or contains nested anodes, some such means normally must be employed since the racks cannot be removed horizontally while the workpieces are immersed.

As another arrangement, particularly advantageous where the treatment time in one solution is substantially greater than in other solutions and where successive immersion is impracticable for plating reasons, a skip transfer arrangement such as the type disclosed, for example, in Patent No. 2,716,415 granted to Davis and Clark on August 30, 1955, and in the copending application of Davis, Serial No. 530,223, filed August 24, 1955 (a continuation-in-part of Davis application Serial No. 397,506, filed December 11, 1953, now abandoned), may be em ployed. Application Serial No. 530,223 issued on April 23, 1957, as Patent No. 2,789,569. In that system, the several racks in the tank are replaced, from the supply of racks from the preceding station or tank, in a predetermined sequence. Thus, each workpiece-carrying rack is immersed in but one cell at the entire station, but a plurality of such cells (or individual tanks) are provided so that the workpieces on a plurality of racks may be treated concurrently.

In any of these arrangements, the racks must be moved in a horizontal sense to advance the workpieces along the line of tanks. As noted, in some cases a part of this horizontal motion may be accomplished with the racks immersed, but in every case where the cells are defined by partitions or include anode nests, in every case where chemical considerations prohibit horizontal movement of the immersed parts, and in every case where the racks are to be transferred from one tank to the next, the horizontal least certain of the adjacent tanks.

purposes, therefore, the term track is intended to be generic both to a single-rail system and to a multiple-rail system.

The track is normally segmentalized so that portions thereof may be raised or lowered relative to others of the portions to permit the selective raising and lowering of the carriers and their racks and loads.

The horizontal transfer is commonly accomplished by pushers engageable with the carriers or racks in the upper or the lower positions of those carriers, as determined by the foregoing considerations. These pushers are customarily operated in an incremental or step-wise fashion so as to advance the carriers but one cells distance in any one continuous movement. The pushers may themselves be repetitively reciprocated or be carried by an extended, endless chain, both as taught in the above-noted patent and disclosures therein referenced, or be otherwise actuated.

In the practice represented in the aforesaid application and patent, transfer stations, drain-transfer stations and/ or rinse-transfer stations are or may be provided between at Each such station comprises a space between the tanks having a fixed track section mounted to support a carrier at the elevated'transfer level. Each of the successive carriers is elevated from the preceding station (comprising one or more tanks) or from the preceding tank, transferred to the fixed-track transfer station, and then, at an appropriate time, is transfererd to a track section individual to the next station so as to be lowered into the tank or tanks thereat.

Where the sole requisite function is that of inter-tank transfer, the intermediate transfer station, and the space required therefor, may be dispensed with by the practice of the principles of the present invention and, in that case, as well as where draining or cleaning is essential, the application of the principles of the invention will normally permit a reduction in the extent and cost of the systems horizontal and vertical carrier transfer mechanism.

.In general, in the exemplary arrangement disclosed herein, a track segment or section is supported so as to be movable in verticaltranslation. This track section is alignable with and disposed adjacent another elevatable track section which is individual to the preceding or succeeding station or stations. The latter section is driven in a vertical sense by electrical, hydraulic, pneumatic or other elevating mechanism, whereas the former is termed a floating section in that there is no driving mechanism individual thereto. In the disclosed system, the positively driven track section is employed to control the vertical movement and position of the floating track section. Thus, in one arrangement, an arm integral with the driven section, or parts moving therewith, is engageable with the floating section, or parts moving therewith, so that upward motion of the driven section will be communicated to and result in the upward movement of the floating section.

It is further contemplated that a single floating track section be disposed between a pair of driven sections, each of the driven sections being so mechanically associated with the floating section that either driven section, in moving upward, will carry the floating section there- 3 with, and so that the floating section will be aligned, at all times, with the uppermost one of those driven sections.

The nature of the invention, and its objects and features, will be more clearly perceived from the following detailed description of a representative embodiment of the invention when read with reference to the accompanying drawings in which:

Figure 1 is a fragmentary side elevational view of a mechanism embodying the principles of the present invention;

Fig. 2 is a vertical sectional view taken substantially along the line 2-2 of Fig. 1;

Fig. 3 is a vertical sectional view taken substantially along the line 33 of Fig. 1;

Fig. 4 is a fragmentary, functional, schematic representation of illustrative arrangements to which the principles of the invention may be applied; and

Fig. 5 is a schematic representation of a circuit for controlling the sequencing of the apparatus of Fig. 4.

In the arrangement depicted in Fig. 1 of the drawings, a floating track assembly is disposed between a pair of assemblies 12 and 14. Each of the assemblies 10, 12 and 14 may be individual to a separate station of the treating or plating system. As an example, assemblies 12 and 14 may each be individual to an operating station such as stations 27 and 29, respectively, in Fig. 1 of the aforesaid patent and application, and assembly 10 may be individual to a passive station such as 28 thereof. However, the advantages of practicing the principles of the invention are most fully realized if assembly 10 hereof is either associated with an individual active tank or rinsing apparatus, or is a part of the total equipment, including either assembly 12 or 14, at one or the other of two adjacent operating stations.

To facilitate an appreciation of the details of the construction, the disclosed arrangement is based upon the structure represented and described in detail in the aforesaid patent, and reference may be had thereto for a more complete understanding of one suitable environment for the present inventive features.

Similar to the arrangement disclosed in that patent, the primary support elements are a plurality of pairs of spaced-apart columns, the

near column

16, 18, and 22 of each pair of which is shown in Figure 1 hereof. Other such columns may be disposed

intermediate columns

16 and 18 and intermediate columns 20 and 22, their shape, location and nature being determined by their function, as will be noted.

In one appropriate arrangement, a frame 26, comprising horizontal members 28 and 30 and vertical members 32 and 34, is disposed between

columnar members

16 and 18, and a similar frame (not shown) is disposed between the corresponding columns on the far side of the machine. The frame members 28 to 34 are representatively shown to be channels (Figs. 1 and 2), with the web of each of the upper and lower channels 28 and 30 being riveted, welded or otherwise attached to one leg of each of the side frame members 32 and 34.

The pair of frames including frame 26 is moved vertically (either upward or downward) through the medium and under the control of a plurality of chains, including chains 36 and 38, driven in synchronism with one another by any appropriate means.

To guide frame 26 in its vertical motion relative to

columns

16 and 18, suitable bearing means may be provided. In the disclosed arrangement, the

columnar members

16 and 18 are Lb'earns and the bearing means comprises a plurality of rollers 40 rotatably mounted relative to the frame 26 and bearing against the webs of the

columnar members

16 and 18.

Further means, not shown, are preferably also provided to maintain the frame 26 in alignment with the

columns

16 and 18. For example, the horizontal frame members 28 and 30 may be extended to engage the outer faces of

columns

16 and 18, with other means being provided to engage the inner faces of those columns. In both cases, side thrust rollers may be and preferably are provided. Alternatively, additional rollers may be mounted upon the frame 26 and engageable with opposing faces of each column or opposing faces of the legs thereof, or intermediate columnar members may be provided between

columns

16 and 18 and presenting faces upon which the frame 26 may slide.

Similar guiding means are or may be provided for the frame on the other side of the machine Corresponding to frame 26.

As may best be seen in Fig. 2 of the drawings, a channel-section rail 44 is welded or otherwise secured so as to be integral with the side members 32 and 34 of the frame 26 and lies in spaced parallelism with the upper frame member 28 but on the opposite side of the frame 26 therefrom. One or more wheels 46 rotatably supported on the carrier 43 are conformed to engage the surface of one leg of the rail 44 (and of the other rails alignable with rail 44 in the system), a flange 5i) preferably being provided to insure accurate lateral positioning of the carrier 48. A similar rail is mounted upon the corresponding frame upon the other side of the machine and similar wheels areprovided upon the other end of the carrier 48 so that the carrier can move longitudinally of the machine upon a'track defined by the opposing rails, including rail section 44. The workpiece-carrying racks are supported upon the carriers 48 in the manner disclosed in the referenced patent.

In the shown lower position of the frame 26, the carriers 48 may be supported upon the rail sections, including rail section 44 or separate means may be provided for supporting those carriers. This means may comprise the side walls of the tanks containing the solutions in which the workpieces are to be immersed, or may comprise a support bar 52, at each side of the machine, supported upon a plurality of stub columns such as column 54.

Assembly 14 may be identical in construction to assembly 12 and corresponding reference numerals, distinguished by a prime, are applied to the corresponding parts.

Assemblies 12 and 14 have been representativeiy described as including pairs of unitary frames, such as frame 26. Each such assembly may be suficiently long to accept a plurality of carriers at one time so as to be capable of raising all of the suspended carriers concurrently, with the horizontal movement of the carriers being accomplished at the upper level. Conversely, each of the assemblies 12 and 14 may be only sufiiciently long to accept but one carrier at a time. In this case, each assembly may be individual to a one-cell station or may be but the last and output portion (assembly 12) or the first and input portion (assembly 14) of a multi-cell station.

Thus, a station may include a first or input portion similar to assembly 14, a last or output portion similar to assembly 12, and an intermediate fixed portion in which the track is rigidly mounted at the lower level, the horizontal transfer of carriers from the preceding station to the first or input portion and from the last or output portion to the succeeding station being performed at the upper level and the horizontal transfer of carriers upon the intermediate fixed portion being accomplished at the lower level.

As another of the plurality of possible arrangements. the track at any station may be segmentalized on a single-cell basis so that any one of the carriers may be sclectively replaced, in the manner taught in the beforenoted patent and application.

Other possible arrangements will be apparent to those skilled in the art.

The floating-rail assembly 10 comprises a horizontal channel support member 58 atfixed to and in spaced parallelism withanequal-length rail Gil (Fig. 3 Angles 62,,.supporting rollers 64, are bolted, riveted or otherwise joined to both channel."58 and rail 60, and additional .interjoining and spacing ,means (not shown) may also be .bridged between members 5,8 and 60 to render them effectively integral.

Additional structural elements may be ,provided to define :a ,full frame, similar toframe .26, but in the disclosed arrangement, a pair'of bars 68, and means supported thereby, serve to guide and stabilize the members 58 and fitl. The ,upperends of bars 68 are aflixed to the assembly including channel 58 and rail section 61!), representatively by being welded to a spacer 70 (Fig. 3) which is, in turn, welded to the rail section 60. Each bar 68 depends from the rail section 60 and extends in alignment with and in proximity to an individual one of thecolumns18 and 20.

The lower end of each bar 68 carries means for transmitting the forces and moments applied thereto to the columns 18 and 20, such as a roller 74 engageable with the web of column 18 or 20 and spaced-apart rollers 76 and 78engageable with the adjacent faces of the legs of column 18 or 20, as may best be seenrin Fig. 3 of the drawings.

It will be appreciated that in the preferred arrangementthere is an assembly corresponding tovassembly 10 on the other side of the machine.

At each side of the machine, a horizontally extending arm .80 is welded or otherwise affixed to the horizontal member 28 and extends so as to underlie the support member 58 of the floating rail section assembly '10, and a similar pair of arms 82 is welded or otherwise affixed to the horizontal member 28' and extends soas to under- 7 eral arms 80 and 82 are not Welded or otherwise attached to the member .58 and do not interfere with oneanother.

As a result of this construction, it frame 26 of 'assembly 12 is drawn upward by means including chains 36 and 38, support member 58 and rail section 60 will be carried therewith, the forces being transmitted thereto through arms 80. Thus, if the upper element 28 of frame 26 is moved to its upper position, as shown in phantom in Fig. 1, support member 53 will be moved therewith to its upper position, alsorepresented in phantom, so that track section 60 (Fig. 3) remains in alignment with track section 44 (Fig. 2). Assuming frame 26 remains in its lower position, when frame 26is forced or permitted to return to its lower position, the floating rail section 60 and parts integral therewith will return to its lower position by virtue of its weight and the weight of any load carried thereby.

Conversely, if frame 26' is elevated by means including chains 36 and 38, the floating rail section 60 and support member 58 will be carried therewith in an identical fashion by the arms including arm 82. Obviously, if under any circumstance, both

frames

26 and 26 are elevated to any degree at the same time, rail section 60 and support member 58 will remain in alignment with the rail sections integral with the uppermost one of those frames.

It will be noted that the bars 68 and the rollers or other bearing means affixed thereto serve not only to stabilize and rigidity the support member 58 and rail section 60 in any position of rest, but also to guide the movement of those elements and to counteract any tendency toward tilting or binding resulting from any moments exerted during the lifting or lowering process. While the arms 80 and 82 are conveniently affixed to members 28 and 28', respectively, and are adapted to engage an under surface of member 68 (and correspondingly on the other side of the machine), they may be attached to any element that moves with those frames and may engage any under surface of any element that moves with the support member 58.

Thus, ,as .an example, for. convenience and clarity of representation, the arms are shown in Fig. 4 of the drawings to be attached directly to the 'rail'sections, it being assumed-that those armsare appropriately disposed so as to interfere neither with the supporting columns, nor any part thereon, nor with the carriers.

It will be noted that the fundamental requirement is only that means be provided for so relating the floating rail section with :a preceding rail section and a succeeding rail section, that thefloating rail section will always be carried upwardly, or held in an upward position, when either of the associated adjacent rail sections is elevated, but so that either of the adjacent rail .sections may be lowered independently of the floating rail section if there is some other means (such as the other adjacent rail section) restraining the floating rail section against downward motion. It will, therefore, be appreciated that the result may be'accomplished by means other than that shown including, for example, a simple reversal of parts whereunder the lifting arms are afiixed to thefloating rail sections, or parts :integral therewith, and extend to be engageable with an upper surface of some element of-the adjacent frame, or parts moving therewith, or by other suitable iengaging means.

As will be seen from the ensuing description'of Fig. 4 of' the drawings, the principles 'of the invention are also applicable where but one of the two rail sections adjacent the floating rail section is provided with means for lifting the floating rail section. In that event, the other adjacent rail section may be fixed in either the upper or lower position.

In the manner disclosed in the aforesaid patent, a pair of-short rail sections are aflixed to each of the several columns, such as

columns

16, 18, 20 and 22, at the upper and lower track levels so that whether any two adjacent track sections, such as sections 44 and 60, are both in their upper or both in their lower'positions, a continuous track 'will be formed for the transfer'of the wheeled carriers. Alternatively, the several track sections such'as sections 44 and 60, may, for example, each extend to the midpoint of each of the two columns with which they are individually associated.

Figure 4 is not intended to show equipment for performing a given plating or treating operation, but rather to show, in an integrated arrangement, the use of a floating rail section lifted by a preceding rail element, a floating rail section lifted by a succeeding rail element, and a floating rail section lifted alternatively 'by either a preceding or succeeding rail element. Thus, the location of the end walls of the several tanks 100, 102, 1 04 and 106 .are purely representative of any of a number of possible arrangements, and the provision of horizontal transporting means effective in the lower position and other .horizontal transfer means effective in the upper position is intended merely to illustrate that the principles of the invention are not restricted to either. appreciated that the disclosed vertical and horizontal transporting means are but schematic and to but symbolically represent any of the hydraulic, pneumatic, electrical, mechanical, elevating and horizontal transporting means known to the art, including the reciprocating pusheror chain-type pusher mechanism disclosed in the aforesaid patent.

The several tanks to 106 are disposed in alignment, and a series of track sections 108 to (each comprising one or more rails) are aligned over those tanks in a position to guide and supprt a plurality of wheel-equipped work-carriers 122 to 138. It is assumed, for purposes of illustration,that track section 112 is fixed in a lower position proximate the tank 102 (but-could, under other circumstances, be fixed in an upper position, with the transfer of work-carriers thereto and therefrom being accom plished at the upper level), that track sections 110, 114 and 118 are floating sections of the type hereinbefore de- It will further be scribed, and that

track sections

108, 116 and 120 are active, elevatable track sections adapted selectively to lift the adjacent floating track sections.

Thus, the means for controlling the vertical position of track section 108 is represented to be hydraulic cylinder C1, the piston rod 140 of which is connected in an appropriate fashion to track section 108 (such as by a linkage and chain arrangement); the means for controlling the vertical position of track section 116 is shown to be a hydraulic cylinder C4, the piston rod 142 is connected to track section 116; and the piston rod 144 of hydraulic cylinder C6 is shown to be connected to track section 120 to control the vertical position thereof.

Due to the provision of arm or arms 148 connected to track section 108 and underlying track section 110, track section 110 will be raised whenever track section 108 is raised; due to the provision of arm or arms 150 integral with track section 116 and underlying track section 114, floating track section 114 will be elevated whenever track section 116 is elevated; and due to the provision of arm or arms 152 aflixed to track section 116 and underlying track section 118, and due to the provision of arm or arms 154 atfixed to track section 120 and underlying floating track section 118, the vertical position of track section 118 will be controlled by both of the track sections 116 and 120. As will be seen, in the disclosed arrangement track sections 116 and 120 are representatively assumed only to be operated alternatively and never concurrently, although other arrangements may be employed in practice including those in which the track sections move in unison.

Based on the foregoing assumptions, the horizontal transfer of a work-carrier from track section 108 to floating track section 110 occurs at the upper level under the control of a hydrauliic cylinder C2, the piston rod 158 of which carries a pusher 160 depending therefrom.

The transfer of a carrier from floating track section 110 to the first cell increment of track section 112, the transfer of carriers along track section 112, and the transfer of the work-carriers from section 112 to track a stops 162 are provided to prevent clockwise rotation thereof.

Similarly, means including hydraulic cylinder C5 are provided for horizontally transferring work-carriers between track sections 114, 116 and 118 as well as among the several incremental cell positions of track section 116, and means including hydraulic cylinder C7 are provided for transferring workpieces between track section 118 and track section 120, in the upper positions thereof, as well as along track section 120, unidirectionally pivotal pushers being provided in each case.

It is assumed that a simple form of hydraulic circuit is provided for each such cylinder in which a solenoid controlled, spring-biased, reversing valve is employed which is effective when its associaed solenoid is deenergized to drive the piston rod of the individual cylinder in one direction and effective when the solenoid is energized to drive the piston rod in the opposite direction. The solenoids which are individual to the several hydraulic cylinders C1 to C7 are identified, in Fig. 5 of the drawings, by a similar reference character prefixed with the letter S, thus solenoid SCI, in Fig. 5, is individual to hydraulic cylinder C1 in Fig. 4, and so forth.

It is assumed that when solenoid SCI is de-energized, piston rod 140 of hydraulic cylinder C1 is extended, with that rod being retracted or moved upwardly when solenoid SCI is energized; that piston rod 158 of cylinder C2 is in its shown leftwardmost position unless its associated solenoid SC2 is operated; that the piston rod of hydraulic cylinder C3 is in its leftwardmost position unless solenoid SC3 is energized; that the piston rod of hydraulic cylinder C4 is in its extended, downward position unless the associated solenoid is energized; that the piston rod of hydraulic cylinder C5 is to the left unless solenoid SCS is energized; that the piston rod of hydraulic cylinder C6 is in its shown lower position unless solenoid SC6 is energized; that the piston rod of hydraulic cylinder C7 is in its shown rightwardmost position unless solenoid SC7 is energized.

Means are provided for determining the efiective condition of the several elements in the system by sensing the positions of the several piston rods of the hydraulic cylinders C1 to C7. Thus, in the schematic representation of Fig. 4, an actuating lug 176 is fixed relative to piston rod and is adapted to trip the down limit switch C1D if piston rod 140 is in its lowermost position, and is adapted to trip the up limit switch ClU if rod 149 is retracted so that track section 108 is in its upper position, as represented in phantom. Similarly,

limit switches C2L and C2R sense the leftmost and rightmost positions, respectively, of the piston rod of hydraulic cylinder C2; limit switches C3L and C3R sense the leftmost and rightmost positions of the piston rod 164 of cylinder C3; limit switches C4D and C4U sense the down and up positions of track section 116 through the medium of sensing the position of piston rod 142, etc.

The operation of the system of Fig. 4 will be described with reference thereto and to the circuit diagram of Fig. 5.

In the schematic of Fig. 5, the symbol to which the reference characters LUlE and LUlR have been applied represents a dual winding, mechanical latching relay, many types of which are available on the market, and other such relays are employed in the circuit. Each such relay is or may be provided with one or more normally open contacts, represented by a pair of spacedapart parallel lines, and one or more normally closed contacts, represented by a pair of spaced-apart parallel lines bridged with an oblique line. The reference characters applied to the contacts are selected to correlate those contacts with the appropriate mechanical latching relay. Upon the energization of the upper, energizing winding of the relay, such as winding LUIE, the state of each contact individual to that relay is reversed. The relay will remain in this condition, even though the application of energy to the energizing winding is terminated, until their release winding, such as winding LUlR, is energized, at which time the contacts will be restored to their normal state and will there remain, even though the release winding is de-energized, until the next energization of the main, energizing winding. All of the limit switches in Fig. 4 of the drawings are representatively shown to have but one contact which is open when the limit switch is not tripped.

In a normal cyclic or sub-cyclic system, a condition precedent is established to the occurrence of each event in order to accomplish proper sequencing. Since the arrangement of Fig. 4 of the drawings is not intended to represent a complete system, it is assumed that the closure of contact A (Fig. 5) denotes the completion of the condition precedent to the operation of the subsystemic combination shown. In practice, contact A may be closed as a result of the appearance at the shown portion of track section 108 (Fig. 4) of a work-carrier, as a result of the completion of the operation of the mechanism which produced that work-carrier positioning, as a result of the completion of any event subsequent in the train (if the operation of cylinder C1 is the first event in a sub-cycle of operations), or as a result of any other appropriate sensed condition.

It will be assumed that a work-carrier, such as workcarrier 122, is present at the shown portion of track section 108, having been transferred thereto either in the upper or lower position of track section 108, and that contactA (Fig. 5) is closed.

All of the mechanically latching relays LUl to LU4 (Fig. 5) are normally released. Hence, with contact is tripped to its closed position.

A closed, the source of voltage S (Fig. is connected through contact A and the now-closed contacts LU2a and across the winding of solenoid SC1. .As noted, this results in the retraction of piston rod 140 of hydraulic cylinder Cl, raising track section 108 to its upper position as represented in phantom in Fig. 4. Since arm or arms 148, integral with track section 108, underlie floating track section 110, track section 110 is raised therewith.

As piston rod 140 commences to rise, limit switch C1D opens, but produces no useful result at this time.

It is assumed that appropriate stops are provided, or that the length of the stroke of hydraulic cylinder C1 is so selected, that track segments 108 and 110 will be stopped in the upper position, shown in phantom,-even though solenoid SCI remains energized. On the basis of the original assumptions, solenoid 501 must remain energized so long as track sections 108 and 110 are to be retained in their upper position, for upon the deenergization of that solenoid, track sections 108 and 110 will be forced or permitted (inaccordance with the hydraulic circuit arrangement) to return to. their lower levels.

As piston rod 140 is retractedto the point where track sections 108 and 110 reach the upper level, limit switch C1U is tripped. Since mechanically latching relay LU1 is not operated at this time, its contact LUla is closed. Therefore, upon the operationof limit switch ClU, solenoid SC2 is energized to cause hydraulic cylinder C2 to drive its piston rod 158 to the right. Work-carrier 122 on track section 108 will, therefore, be engaged by the pusher or pushers 166 (which need not be pivotally mounted) and will be horizontally transferred to floating track section 110.

At the-beginning of this transfer operation, limit switch C2L will be released, producing no useful result at this time, and as the piston rod 158 arrives at its rightwardmost position, limit switch C2R will be tripped. Upon the operation of limit switch C2R, winding LUlE of mechanically latching relay LU1 is energized -to operate thatrelay, and it will remain sooperated even though limit switch CZR is subsequently opened.

Relay LU1, in operating, opens its contact LUla to release solenoid SCZ. Hence, piston rod 158 will be retracted to the left to its normal position,;as shown, in

preparation for the neXt cycle of operations. As piston rod 158 reaches its normal position, limit switch C2L Since relay LU1 is now operated and contact LUlb is now closed, the closure of limit switch C2L at this time will result in the operation of mechanically latching relay LUZ due to the'energization of its winding LUZE. As a result, contact LU2a is opened, solenoid SCl is derenergized, and hydraulic cylinder C1 will permit or force the track sections 108 and 110 to descend to their lower level. Hence, carrier 122 has been transferredfrom tank 100=totank 102 over the intervening tank wall or walls.

As those track sections, and piston ,rod .140, attain their lowermost positions, limit-switch C1D is tripped to complete an energizing circuit for solenoid 8C3 through the now-closed contact LUlc. Consequently, hydraulic cylinder C3 will force piston rod 164 and pushers 166 to 172 to the right, moving work-carrier 128 from the .final position on track section 112 to track section-114,

advancing work-carriers 124 and .126 along tracksection 112, and moving work-carrier 122 from track section 110 to the position on track section 112 previously occupied by work-carrier 124.

As piston rod 164 reaches its rightward position, limit switch C3R is tripped to energize winding LUIR to release mechanically latching relay ,LUl. The resultant opening of contact LUlc dc-energizes solenoid SC3 so .that hydraulic cylinder C3 retracts the piston rod 164 to the leftward, normal position as shown. It will be noted that pushers 168, 170 and 172 will freely pivot tion to the left of the carriers in preparation for the next horizontal translational movement.

As piston rod 164 attains its normal position, limit switch C3L is tripped. Since contact LUZb is now closed, since contact LUld is now closed (due to the previous release of relay LU1) and since contact LU4a is now closed, the operation of limit switch C3L will produce the energization of solenoid SC4 to cause hydrauliccylinder C4 to move track section 116 to its upper, limit position, as represented in phantom. Since arm or arms 150, integral with track section 116, underlie track section 114, track section 114 will be carried therewith. Similarly, since arm or arms 152, integral with track section 116 underlies floating track section 118, thatfloating track section will also be carried therewith.

As these track sections and piston rod 142 reach their upper limit position, limit switch C4U is tripped, which produces the energization of solenoid SC5 since contact LU3a is now closed. The energization of solenoid SC5 section 114 to the first position on track section 116. Atv

the appropriate right-hand limit position of this motion, limit switch CSR is tripped to operate mechanically latching relay LU3 by energizing winding LU3E thereof. The resultant opening of contact LU3a de-energizes solenoid SCS to cause hydraulic cylinder C5 to retract its piston rod, the pivotal pushers freely passing over the work-carriers during that motion. When the normal position is attained, limit switch CSL is tripped which results in the operation of mechanically latching .relay LU4 since contact LU3b is nowclosed.

The operation of relay LU4 serves to open contact LU4a so that solenoid SC4 is de-energized, permitting or forcing track sections 114, 116 and 118 to descend to their lower positions. When the down limit switch C4D is tripped, solenoid SC6 is energized inasmuch as contact LU4b is now closed. As a result, hydraulic cylinder C6 lifts track section 120 toward its upper position. Since arm or arms 154 underlies floating track section 118, that floating track section is again raised to its upper position.

It will be noted that if any work-carrier on tracksection 118, when it is in its lower position, is to receive a treatment in tank 104 or if a partition or tank wall 176 is provided so that a work-carrier on track section 118 is to receive a different treatment or be cleaned, itmay be desirable to interpose a delay between the two successive elevations of track section 118 to control that time of treatment or cleaning, as will be appreciated by those skilled in the art.

As track sections 118 and 120 reach their upper limit position, limit switch C6U is tripped to operate solenoid SC7, since contact LU2d is now closed. Hydraulic cylinder C7 responds to drive its piston rod 178 to the left, the pivotal pushers thereon riding over the carriers on track sections 118 and 120 in the process. When limit switch C7L is tripped, mechanically latching relay'LU2 is restored to normal by virtue of the energization of its restoring winding LUZR, opening contact LUZa' to deenergize solenoid SC7. As a result, hydraulic cylinder C7 retracts its piston rod to advance carriers 136 and 138 upon track section 120 and to transfer workcarrier 134 from thefloating track section 118 to the initial work-carrier position on track section 120.

It will be noted that whether the horizontal translation of the work-carriers occurs on the forward stroke of the hydraulic cylinder, as in the cases of cylinders-C2, C3 andCS, or upon the return stroke, as in the case of cylinder C7, is not significant in the operation of the system.

1 1 It will also be noted that upon the release of mechanically latching relay LUZ, contact LUZa is again closed and, hence, the cycle described to this point may or may not recommence in accordance with the present state of contact A.

When the carriers are fully advanced, limit switch C7R is tripped to complete a circuit through now-closed contacts LU3c and LUZc to energize the restoring winding LU4R to restore mechanically latching relay LU4 to normal. The resultant opening of contact LU4b deenergizes solenoid SC6 so that track section 126 and floating track section 118 will be permitted or forced to descend to their lower levels. At that time, limit switch C6D will be tripped, This closure of switch C6D coupled with the operated status of mechanically latching relay LU3 and the released status of mechanically latching LUZ is a unique condition first occurring at this point in the cycle, and consequently, may be employed as a signal to the next succeeding systemic element.

In order that the disclosed sub-system elements may be restored fully to normal at some point in the total cycle, it is assumed that some succeeding event produces the closure of contact B (Fig. to energize the restoring winding LUSR of mechanically latching relay LU3.

It will be appreciated that in practice it may be advantageous to provide different sequencing of the vertical (upward or downward) movements of track sections 116 and 120. Thus, in some circumstances it may be desirable to elevate track section 116, carrying track section 118 therewith, elevate track section 120, and then lower track section 116, the floating track section 118 being retained in the upper position by track section 129. Thus, the arrangement of Fig. 4 is but representative of one of a plurality of possible applications of the principles of the invention.

While it will be apparent that the embodiment of the invention herein disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. In a machine having a liquid-treating station for treating work supported upon work-carriers, a generally horizontally disposed track adapted to support the Workcarriers, said track comprising three discrete, longitudinally alignable track sections, means for moving one of said track sections generally vertically, means for moving another one of said track sections generally vertically and independently of the vertical motion of said one track section, means including said one track section for moving the remaining one of said track sections generally vertically, and means including said other track section for moving said remaining one of said track sections generally vertically.

2. In a machine having a liquid-treating station for treating work supported upon work-carriers, a generally horizontally disposed track adapted to support the workcarriers, said track comprising three discrete, longitudinally alignable track sections, first actuating means for moving one of said track sections generally vertically, second actuating means for moving another one of said track sections generally vertically and independently of the vertical motion of said one track section, means including said one track section for moving the remaining one of said track sections generally vertically, means ineluding said other track section for moving said remaining one of said track sections generally vertically, and means for alternatively ener izing said first and second actuating means.

3. In a machine having a liquid-treating station for treating work supported upon workcarriers, a generally horizontally disposed track adapted to support the workcarriers, said track comprising first, intermediate, and third discrete, longitudinally alignable track sections,

12 means for moving said first track section generally vertically, means for moving said third track section generally vertically, means including said first track section for moving said intermediate track section generally vertically, and means including said third track section for moving said intermediate track section generally vertically.

4. In a machine having a liquid-treating station for treating work supported upon work-carriers, a generally horizontally disposed track adapted to support the workcarriers, said track comprising first, second, and third discrete, longitudinally alignable track sections, means for moving said first track section generally vertically, means for moving said third track section generally vertically, and means for continuously positioning said second track section in alignment with the uppermost one of said first and third track sections.

5. In a machine having a liquid-treating station for treating work supported upon work-carriers, a generally horizontally disposed track adapted to support the workcarriers, said track comprising first, intermediate, and third discrete, longitudinally alignable track sections, means for moving said first track section generally vertically, means for moving said third track section generally vertically, and means for continuously positioning said intermediate track section in alignment with the uppermost one of said first and third track sections.

6. In a machine having a liquid-treating station for treating work supported upon work-carriers, a generally horizontally disposed track adapted to support the workcarriers, said track comprising first, second, and third discrete, longitudinally alignable track sections, means for moving said first track section generally vertically, means for moving said third track section generally vertically, and means for continuously positioning said second track section in alignment with the uppermost one of said first and third track sections comprising a first member interrelating one pair of said track sections by being fixed relative to one of said pair of track sections and engageable with a surface etfectively integral with the other one of said pair of track sections and a second member interrelating another pair of said track sections by being fixed relative to one of said other pair of track sections and engageable with a surface effectively integral with the other one of said other pair of said track sections.

7. In a machine having a liquid-treating station for treating work supported upon work-carriers, a generally horizontally disposed track adapted to support the workcarriers, said track comprising first, second, and third discrete, longitudinally alignable track sections, means for moving said first track section generally vertically, means for moving said third track section generally vertically, and means for continuously positioning said second track section in alignment with the uppermost one of said first and third track sections comprising a first member fixed relative to said first track section and engageable with a surface efiectively integral with said second track section and a member fixed relative to said third track section engageable with a surface etfectively integral with said second track section.

8. In a machine having a liquid-treating station for treating work supported upon work-carriers, a generally horizontally disposed track adapted to support the workcarriers, said track comprising first, intermediate, and third discrete, longitudinally alignable track sections, means for moving said first track section generally vertically, means for moving said third track section generally vertically, and means for continuously positioning said intermediate track section in alignment with the uppermost one of said first and third track sections comprising a member fixed relative to said first track section and engageable with a surface effectively integral with said intermediate track section and a member fixed relativeto said third track section and engageable with a surface effectively integral with said intermediate track section.

9. In a machine having a liquid-treating station for treating work supported upon work-carriers, a generally horizontally disposed track adapted to support the workcarriers, said track comprising first, intermediate, and third discrete, longitudinally alignable track sections, means for moving said first track section generally vertically, means for moving said third track section generally vertically, and means for continuously positioning said intermediate track section in alignment with the uppermost one of said first and third track sections comprising a member fixed relative to said intermediate track section and engageable with a surface effectively integral with said first track section and a member fixed relative to said intermediate track section and engageable with a surface effectively integral with said third track section.

10. The combination according to claim 1 further characterized in this that each of said track sections comprises a pair of opposed rails.

11. The combination according to claim 4 further characterized in this that each of said track sections comprises a pair of opposed rails.

12. In a machine having a liquid-treating station for treating work supported upon work-carriers, a generally horizontally disposed track adapted to support the workcarriers, said track comprising first, second and third discrete, longitudinally alignable track sections, each of said sections being movable in translation between an upper and a lower position, actuating means for moving said first section from the lower position to the upper position and back to the lower position, actuating means for moving said third section from the lower position to the upper position and back to the lower position,

means for alternatively energizing said actuating means, I

and means for continuously maintaining said second section in alignment with the uppermost one of said first and third sections.

13. In a machine having a liquid-treating station for treating work supported upon work-carriers, a generally horizontally disposed track adapted to support the workcarriers, said track comprising first, second and third 14 discrete, longitudnially alignable track sections, each of said sections being movable in translation between an upper and a lower position, actuating means for moving said first section from the lower position to the upper position and back to the lower position, actuating means for moving said third section from the lower position to the upper position and back to the lower position, means for alternatively energizing said actuating means, means for continuously maintaining said second section in alignment with the uppermost one of said first and third sections, and means for transferring a carrier from said first section to said second section while said first and second sections are in their upper positions.

14. In a machine having a liquid-treating station for treating work supported upon Work-carriers, a generally horizontally disposed track adapted to support the Workcarriers, said track comprising first, second and third discrete, longitudinally alignable track sections, each of said sections being movable in translation between an upper and a lower position, actuating means for moving said first section from the lower position to the upper position and back to the lower position, actuating means for moving said third section from the lower position to the upper position and back to the lower position, means for alternatively energizing said actuating means, means for continuously maintaining said second section in alignment with the uppermost one of said first and third sections, means for transferring a carrier from said first section to said second section whilesaid first and second sections are in their upper positions, and means for transferring a carrier from said second to said third section while said second and third sections are in their upper positions.

References Cited in the file of this patent UNITED STATES PATENTS 1,614,213 Smith Jan. 11, 1927 1,736,846 Cole Nov. 26, 1929 2,591,681 Davis Apr. 8, 1952