US 3578002 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
2,924,229 2/1960 Kearneyetal................ 134/79 3,134,203 5/1964 Roberts........... l34/157X 3,350,224 10/1967 Sadwith........................ 134/157X FOREIGN PATENTS Primary ExaminerMorris O. Wolk Assistant Examiner-Joseph T. Zatarga Attorney-Frederick W. Padden lnventors Henry A. Rowan Watchung; Donald H. Shiffner, Branchburg, NJ. [21 Appl. No. 860,957 5 Sept. 25, 1969  Patented May 11,1971
Economics Laboratory, lnc. St. Paul, Minn.
APPARATUS AND METHOD FOR PROCESSING WORKPIECES United States Patent  Filed  Assignee ABSTRACT: Apparatus for processing (e.g., cleaning,
degreasing) workpieces which are supplied to the apparatus in containers or tote boxes includes a frame for removably en- 159 gaging the tote box and means for continuously rotating the B 81) 3/06 frame so that the workpieces are progressively and gently 10, dumped into a perforated processing chamber and subsequently returned to the tote box. The processing-chamber comprises a first inclined surface for receiving and spreading the dumped workpieces into a less confined area upon the partial rotation of the frame (whereupon the processing of parts may be commenced) and a second inclined surface for return- 134/25X ing the processed workpieces to the tote box upon the further 202/ 170 rotation of the frame. Methods for such processing, as well as 134/31X carousel and conveyor systems incorporating such apparatus, 134/ 1 lUX are also disclosed.
O 7 0 1 l 2 0 m m mmw WW mm m :7 Nm m mm m W 9 mmmmm .m an: m: m w F OflW m: mrm mm mm :2 m m w mm no MK ..1 u 3 6 H 12.1 5 m mwm m u HHH n m m 64m l C S d 5111. 3 1 1 1 11 1 own 2 10 6 h .1 15. M51 222 PATENTEU HAY] 1 l97| sum 1 or 5 INVENTORS: hi A. ROWAN D. H. Sl-l/F F NE R SOLUTION LEVEL ATTORNEY PATENTED mm 1 l97l Y 3578.002
/N VENTORS: HCA.IQOMOHV /2 4 By D. H. SH/f'FNER A TTORNEV PATENTEU HAY] 1 ml sum 3 0F 5 FIG. 21 (360) DRY woe 5 IN VE TORS MA. ROW/1 1v 0. H. SHIFFNER v PAT ENTED um I new SHEET t UF 5 \soLunoN LEVEL 24 14 /NVENTORS-' H. A. ROWAN By D. H. SH/FFNER A 7' TORNEY PATENTED. m1 1 l97l SHEET 5 BF FIG. 5
ANTI RUST SPRAY STAGE 4 I WASH STAGE 3 WASH STAGE 2 LLOAD-UNLOAD STAGE l H N N ,MAE m. R W N T 00...! .7 M 4 MAM. D vr a APPARATUS AND METHOD FOR PROCESSING WORKPIECES BACKGROUND OF THE INVENTION This invention relates to apparatus and methods for processing workpieces of various size and shape which are supplied to the apparatus in containers or tote boxes, and, more particularly, to such apparatus and method for processing workpieces in a single material handling operation by means of a unique cleaning chamber.
The prior art is replete with a variety of techniques for processing'workpieces which are furnished to the processing apparatus in tote boxes or other similar containers. Generally, the processing involves cleaningor degreasing the dirty parts or workpieces by fastening the tote box to a perforated cover which permits the ingress and egress of cleaning fluid, rinsing fluid and drying air or the like. The container defined by the tote box and perforated cover is typically rotated so that the workpieces are dumped into the cover and thereby exposed to fluids or air as the case may be.
Numerous problems exist in such prior art processes, a few of which will be briefly discussed. First, in order to secure the cover to the tote box, close tolerances in the dimensions of the tote box must be maintained. However, even normal usage of the tote boxes results in the boxes being dented, warped or otherwise damaged, frequently to the extent the damaged tote box can not be utilized in the processing operation. Secondly, it is typical that the tote box and cover are of congruent shape, usually a rectangular volume. When the workpieces are dumped into the perforated cover, they occupy essentially the same volume in the cover as in the tote box. No spreading of the pieces occurs. Consequently, little, if any, additional surface area of the pieces is exposed to the processing fluids. As a result the entire processing operation is relatively inefficient, requiring the pieces to be reprocessed repeatedly until predetermined standards are met. Thirdly, prior art processors are adapted to clean only the workpieces and not the tote box. Thus, the processed pieces are returned to dirty tote boxes which must be processed separately.
It is therefore a broad object of the present invention to process workpieces efficiently.
It is another object of this invention to process workpieces of various size and shape supplied in tote boxes or similar containers.
It is still another object of this invention to process workpieces supplied in tote boxes even though the tote boxes be dented, warped or otherwise damaged so as to prevent the securing of a cover thereon.
It is yet another object of this invention to process both workpieces supplied in tote boxes as well as the tote boxes themselves.
It is a further object of this invention to process efficiently workpieces supplied in tote boxes by spreading them into a less confined area, processing the pieces and subsequently returning the processed pieces to the tote box.
It is still a further object of this invention to process workpieces in one material handling operation.
SUMMARY OF THE INVENTION These and other objects are accomplished in accordance with an illustrative embodiment of the invention comprising apparatus for processing workpieces supplied to the apparatus in tote boxes or similar containers. The apparatus includes a frame adapted to removably engage the tote box and means for continuously rotating the frame so that the workpieces are progressively and gently dumped into a perforated processing chamber and subsequently returned to the tote box upon the completion of a predetermined stage of the processing operatron.
The processing chamber comprises a first inclined surface for receiving and spreading the dumped workpieces into a less confined area upon partial rotation of the frame. At this stage the processing of the pieces is typically commenced. The
chamber also includes a second inclined surface for returning the processed workpieces to the tote box upon the further rotation of the frame.
A plurality of frame-chamber assemblies are readily affixed radially on a shaft for rotation, and in one embodiment means are provided for translation of the shaft so that the chambers may, for example, be alternately immersed into and emersed from a processing bath while rotation of the shaft and chamber continues.
'Multistep processing is effectuated in two illustrative embodiments of the assembly utilized in either a conveyor belt system or a carousel arrangement.
It is apparent therefore that the method of the present invention in one embodiment includes the steps of: placing workpieces in tote box or container, placing the container in a frame of an assembly for rotation, the frame being partially enclosed by first and second inclined surfaces, rotating the assembly and thereby progressively gently dumping said pieces onto said first inclined surface, rotating the assembly further thereby causing said parts to spread and to expose more surface area, subjecting said pieces during at least one of said prior rotation steps to a processing fluid, rotating the assembly still further thereby causing said parts gently and progressively to dump onto said second inclined portion and rotating the assembly further yet causing the processed parts to return to said tote box.
BRIEF DESCRIPTION OF THE DRAWING The above and other objects of the invention, together with its various features and advantages, can be easily understood from the following more detailed discussion, taken in conjunction with the accompanying drawing, in which:
FIG. 1 is a pictorial view of one embodiment of the inventron;
FIGS. 2A-2I are schematic drawings of a second embodiment of the invention showing sequentially the various stages of rotation of the assembly;
FIG. 3A is an elevation view of an embodiment of FIG. 1 housed in apparatus for automatic processing;
FIG. 3B is a side view of FIG. 3A;
FIG. 4 is a schematic of another embodiment of the invention showing four assemblies mounted upon a shaft for rotatron;
FIG. 5A is a plan view of carousel arrangement for multistep processing;
FIG. 5B is anelevation view of FIG. 5A;
FIG. 6 is a schematic of a conveyor belt arrangement incorporating the assembly of the invention.
With reference then to FIG. 1, there is shown in accordance with one illustrative embodiment of the invention an assembly 10 for use in the processing of workpieces supplied in a tote box I2 or other similar container such as a basket. The processing can include, among other operations, washing, drying, spraying, degreasing or any combination thereof. The tote box 12 is engaged by the frame 14 by means of angle irons 16 which form a slot into which the box is inserted. The lateral separation of the angle irons is preferably slightly less than the width of the bottom of the box so as to provide a pressure fit. In addition, it is desirable that the angle irons be inclined soas to conform to any taper in the sides of the tote box (see FIG. 3A). Other means of securing the tote box to prevent slippage during rotation of the frame 14 can, of course, be readily devised by those skilled in the art without departing from the spirit and scope of the invention. For example, it may be desirable to provide the frame 14 with a spring-load mechanism to further insure against slippage.
\ In the following discussion a frame a reference for clockwise rotation, and with tote box 12 in an upright position, is assumed for the purposes of clarity and convenience only. An equivalent description for counterclockwise rotation would, of course, be obvious to one skilled in the art.
The assembly is typically rotated clockwise about a shaft 18 so as to dump the workpieces from the box and subject them to processing operations. To efficiently effectuate such processing, the frame is partially enclosed by a perforated chamber comprising a first inclined, curved surface 20 for receiving and spreading the workpieces upon partial rotation of the shaft 18 and hence the tote box 12. Surface 20, which is shown to be concave inwardly toward the axis of rotation of shaft 18, extends upwardly and to the left from a region near to one top edge 13 of tote box 12 a distance along the surface greater than the width of the tote box opening to a region remote from the opposite top edge 157 The chamber also includes a second inclined surface 22, connected to curved surface 20, for returning the processed workpieces to the tote box upon further rotation of shaft 18. As shown in FIG. 1 the surface 22 may illustratively be constructed in the form of 'a trapezoidal chute having lateral raised triangular Wings 220 and 22b disposed on either side of surface 22 to assist in preventing workpieces from sliding laterally out of the chamber. Surface 22 extends downwardly and to the right from the remote portion 21 of surface 20 to the vicinity of top edge of tote box 12. Of course, receiving and spreading surface is preferably perforated to allow the ingress and egress of processing fluids and the like. Surface 22 may or may not be perforated as the particular processing operation dictates.
Before discussing in detail the embodiment of the foregoing frame-chamber assembly in a complete processing machine, it will be helpful to consider in detail the manner in which the assembly efiiciently etfectuates the processing. Turning then to FIGS. 2A to 21, there is shown schematically a second embodiment of an assembly 100 in various stages of rotation of shaft 18. In this embodiment only planar surfaces are utilized. Thus, the receiving and spreading surface comprises an inclined surface 200 extending, as before, from a region near to one top edge 13 of tote box 12 upwardly and to the left to a region remote from the opposite top edge 15; and a horizontal surface 20b connected to the remote edge 25, of surface 20a. As before, the distance along surfaces 200 and 20b is greater than the width of the tote box opening. Similarly, the return surface comprises a vertical surface 22c connected to one edge 23 of horizontal surface 20b and an inclined surface 22d connected to the free edge of surface 22c and extending downwardly and to the right to the vicinity of top edge 15 of tote box 12.
For the purposes of illustration consider that each stage shown by the separate drawings represents a rotation of shaft 18 through 45. While the drawings depict discrete stages, it is nonetheless possible and probably preferable that the rotation be continuous. The following discussion applies equally as well, of course, to the assembly embodiment of FIG. 1. Thus, in FIG. 2A the assembly 10a is shown mounted on shaft 18 and disposed completely above a solution level 24. The workpieces 11 in tote box 12 are indicated generally to occupy the space up to the irregular dashed line. Upon rotation of shaft 18 through 45 (FIG. 2B) the frame 14, tote box 12 and workpieces 11 are immersed into the solution. The workpieces still remain in the tote box but begin to slide to one side. Rotation through 90 (FIG. 2C) begins the gradual and progressive dumping of the workpieces onto the receiving and spreading surface 20. At 135 of rotation, the workpieces 11 are completely dumped and spread out over surface 20. It is to be especially noted that in this stage of the processing the workpieces are spread into a less confined area as compared with the original enclosure in the tote box (FIG. 2A). This separation of the workpieces permits effective application of the processing fluids (liquids or vapors). As the assembly continues to rotates, the workpieces move with respect to one another thus exposing more and different surfaces, thereby assuring thorough processing. In addition, this assembly effectively processes (e.g., cleans) the tote box as well. Rotation through 180 (FIG. 2F.) causes the workpieces to accumulate on surface 20b in preparation for their return to the tote box 12. After 225 and 270 of rotation (FIGS. 2F and 2G, respectively) the workpieces begin to gradually flow back to the tote box being guided by return surface 22. After 270 the entire assembly is again completely above the solution level 24. Upon 315 of rotation (FIG. 2H1) the workpieces begin to move down return surface 22 and finally after 360 the processed workpieces 11 are completely returned to tote box 12. With each 360 rotation the workpieces are emptied from the tote box, spread out and then returned to the tote box. Rotation typically continues throughout the processing cycle which may include, for example, a drain period.
One way in which such a processing cycle can be embodied is shown in FIGS. 3A and 3B. A pair of frame-chamber assemblies 10 are disposed diametrically opposite each other on shaft 18 for rotation in the direction of the arrow. The shaft and assemblies are enclosed within a housing 30 which includes a solution tank 32 for processing the workpieces 11. The tote boxes are supplied to the housing and assembly by means of a cantilevered roller bearing platform 31. With each tote box secured in separate assemblies by angle irons 16 as previously described, the shaft 18 is set into rotation by means of motor 34 housed in enclosure 35 and coupled to shaft 18 via a pulley mechanism including pulleys 36 and 38 and belt 40. To lower the assemblies so that upon rotation each is immersed in the solution, the shaft 18 shown in FIG. 3A is translated to position 18 either manually or by automatic motor drive means not shown. As previously described, with the shaft in position 18 the workpieces are progressively and gently dumped from the tote boxes into the chamber, spread out, processed and subsequently returned to the tote boxes. While the shaft continues to rotate, it may be raised to its initial level to allow for rinsing, draining, drying or other processing operations.
While the embodiment of FIG. 3A depicts only two assemblies disposed upon shaft 18, it is readily possible to adapt the assemblies such that virtually any plurality of assemblies, within space and structural limitations, can be mounted on the shaft. FIG. 4, for example, shows four assemblies 10a, 10b, 10c and 10d mounted symmetrically about shaft 18. Each as sembly of such an embodiment functions essentially the same as the assembly described with reference to FIGS. 2A to 21. In general, a plurality N of such assemblies 10 may be disposed circumferentially about shaft 18 in a symmetrical arrangement in which each assembly occupies approximately an angular sector of 360/N".
The assembly as described may be embodied in a singlestage immersion or spray-type apparatus or may be utilized in multistage operations controlled either manually or automatically. One such multistage apparatus is shown in the carousel configuration of FIGS. 5A and 58. Pairs of tote boxes 12 are furnished to the carousel on a conveyor 42. The tote boxes are inserted within a cylindrical container 44 which houses a pair of frame-chamber assemblies mounted on a shaft 18 as previously described. The shaft is turned by rotation drive 46 coupled to the shaft by belt 48 and pulley 50.
In the load-unload stage 1, the container 44, including the tote boxes 12 and a cover 52, are pneumatically lifted by means of air cylinders 54 and subsequently rotated by means of indexing air cylinder 56 to stage 2 designed for the purpose of illustration only as a wash stage. The air cylinder 54 then lowers the tote boxes 12 and container 44 into the stage 2 housing 58 and the cover 52 is set in place over the top of the housing. During this stage a cleaning solution of the spray or immersion type is applied to the workpieces being rotated by shaft 18. The solution or spray may be heated by means of gas burner 60. Upon the completion of the stage 2 washing, the air cylinders 54 lift the container 44 and tote boxes 12 out of housing 58 and the indexing air cylinder 56 rotates both to the next stage i.e., wash stage 3. The entire procedure is then repeated with the tote boxes being progressively rotated to each stage, processed and rotated to the next succesive stage. Illustratively, the successive stages include antirust spray stage 4 (including pump 59, filter 61 and gas exhaust 63), dry stage 5 (including hot air equipment 65) and finally unloading stage '1.
It is to be understood that the above-described arrangements are merely illustrative of the many possible specific embodiments which can be devised torepresent application of the principles of the invention. Numerous and varied other arrangements can be devised in accordance with these principles by those skilled in the art without departing from the spirit and scope of the invention. in particular, single or multistage processing can be accomplished in a conveyor belttype arrangement as shown in FIG. 6. A plurality of frame: chamber assemblies are mounted on a chainbelt 62 which is driven by a motor 64 through a drive wheel 66. Each assembly 10 is aifixed to the chain belt 62 by meansof an arm 70 rigidly attached to a gear or pinion 68, the latter being rotatably mounted on the belt. As the pinion 68 engages the rack 72, the pinion 68 andhence the assembly 10 is made to rotate causing the workpieces llto be dumped and spread as previously described. To effectuate 360 of rotation the length of the rack should be approximately equal to the circumference of the pinion. Alternatively, to produce a plurality of complete rotations the length of the rack may be made an integral multiple of the circumference of the pinion. in addition, the rack 72 is disposed above a processing station (e.g., solution tank 74) at such a height that upon rotation of the assembly 10 at least the workpieces are immersed in the solution. Of course, the arm 70 may readily be designed such that the tote box 12 is also immersed, thereby allowing the box'to be processed as well.
1. Rotatable apparatus for processing workpieces supplied to said apparatus in an open container, in a frame of reference for clockwise rotation and in which said container is in an upright position, said apparatus comprising means for engaging said container to prevent slippage thereof upon rotation of said apparatus,
first surface means for receiving and-progressively spreading workpieces dumped from said container upon the partial rotation of said apparatus, said workpieces thereupon being subject to processing operations, said first surface means extending upwardly and to the left from a region near to one top edge of said container a distance along said surface means greater than the width of said container opening to a region remote from the opposite top edge of said container, and
second surface means for progressively returning said processed workpieces to said container upon further rotation of said apparatus, said second surface means extending downwardly and to the right from said remote region to a region near to the opposite tope edge of said container.
2. The apparatus of claim 1 wherein said engaging means comprises a frame for carrying said container, and
means forming an elongated slot in said frame of width slightly less than the width of the bottom of said container, thereby to provide a pressure fit for said container and to prevent its slippage upon rotation of said tip paratus.
3. The apparatus of claim 2 wherein said slot forming means comprises a pair of parallel angle irons disposed in spaced relation to one another, their spaced-apart distance corresponding to the width of said slot.
4. The apparatus of claim 1 wherein said first means comprises a first inclined perforated planar surface extending upwardly and to the left from a region near to one top edge of said contained to a region remote from the opposite top edge of said container, and
a substantially horizontal perforated surface having one edge connected to the uppermost edge of saidfirst inclined surface, said surfaces in combination functioning to'receive and spread workpieces upon the partial rotation of said apparatus.
5. The apparatus of claim 4 wherein said second means comprises a substantially vertical planar surface having one edge connected to a free edge of said horizontal surface, and a second inclined planar surface having one edge connected to a free edge of said vertical surface and extending 5 downwardly and to the right to a region near to said opposite top edge of said container so that said workpieces are returned to said container upon the further rotation of said apparatus.
6. The apparatus of claim 1 wherein said first means comprises aperforated surface curved concavely inward toward the center of rotation of said apparatus.
7. The apparatus of claim 6 wherein said second means comprises an inclined surface coupled to said curved surface along-the uppen'nost edge thereof in said remote region so as 5 to form one continuous surface. I
8; The apparatus of claim 7 wherein said inclined surface includes a trapezoidal section and a pair of raisedwing triangular members disposed on opposite edges of said section which also'extend from said uppermost edge of said curved surface in the direction of said opposite top'edge of said container, thereby to prevent lateral slippage of said workpieces from said-inclined surface upon the rotation ofsaid apparatus.
9. The apparatus of claim l in combination with means for rotating said apparatus about an axis so as to progressively dump said workpieces from said container into said first means, and means for positioning said apparatus from one processing station to another. I 3O 10. The combination of claim 9 including a plurality of processing stations disposed circumferentially about a center and including a loading and unloading station, and wherein said. rotating means comprises a cylindrical container, a
rotatable shaft extending axially therethrough, at least one of said apparatus mounted upon said shaft,
means for loading said open containers with workpieces therein into the apparatus in said cylindrical container, means for sequentially positioning said loaded cylindrical container at each of said stations,
means at each of said stations for subjecting said workpieces in said containers to preselected processing operations,
' and means for rotating said shaft and hence said apparatus at each of said stations.
11. The combination of claim 10 wherein each of said processing stations comprises an enclosure having an opening on its top surface for receiving said cylindrical container,
pneumatic means for controlling the vertical position of said cylindrical container, said means being adapted to lift saidcylindrical container above the height of said enclosure,
index air cylinder means for rotating the said cylinder to a position above the opening, said pneumatic means being adapted to thereuponlower said cylindrical cylinder into said enclosure.
12. The combination of claim 9 wherein said rotating means comprises a rotatable shaft to which at least one of said apparatus is coupled so that upon rotation of said shaft about its longitudinal axis said work pieces are first dumped from said container into said first means and subsequently returned to said container by said second means,
means for rotating said shaft about its longitudinal axis, and
wherein said positioning means comprises means for translating said shaft in a direction normal to its longitudinal axis to a plurality of positions, and
means for subjecting said workpieces to processing operations in each of said positions.
13. The combination of claim 12 wherein said subjecting means comprises a tank for carrying a processing solution and an enclosed space for confining processing vapors, and wherein said positioning means comprises means for translating said apparatus from immersion in said tank solution to exposure to vapors in said enclosed space, said shaft and apparatus being rotated continuously in each of said positions.
14. The apparatus of claim 12 wherein a plurality N of said apparatus are disposed circumferentially around said shaft in a symmetrical arrangement in which each of said apparatus occupies approximately an angular sector of 360/N.
15. The combination of claim 14 wherein a pair of said apparatus are coupled to said shaft and are disposed in l 80 sectors diametrically opposite one another with respect to said shaft as a center of symmetry.
16. The combination of claim 9 wherein said positioning means comprises a conveyor belt,
means for rotatably connecting at least one of said apparatus to said belt comprising a gear rotatably affixed to said belt, said gear and apparatus being rigidly affixed to one another,
means adjacent to each of said processing stations for rotat ing said gear upon the translation of said belt, so as to cause said apparatus to rotate, and
means for translating said belt.
17. The combination of claim 16 wherein said gear rotating means comprises an elongated horizontal rack having a plurality of teeth disposed so as to engage said gear.
18. The combination of claim 17 wherein the length of said rack is approximately equal to an integral multiple of the length of the circumference of said gear.
19. Rotatable apparatus for processing workpieces or parts of various size and shape supplied to said apparatus in at least one rectangular tote box, in a frame of reference for clockwise rotation and in which said tote box is in an upright position, said apparatus comprising an elongated rectangular frame having a bottom surface and a pair of side surfaces, a pair of parallel spaced-apart angle irons affixed to said bottom surface so as to form a slot for receiving a tote box, the separation of said angle irons being slightly less than the width of the bottom of said tote box,
first means for progressively and gently receiving and spreading said workpieces upon the partial rotation of said frame about its elongated axis, said first means comprising a curved surface portion perforated for permitting the ingress and'egress of processing fluids and connected to one side surface of said frame, and extending upwardly and to the left from a region near to one elongated top edge of said tote box a distance along said surface greater than the width of the opening of said box to a region remote from the opposite elongated top edge of said tote box, said workpieces thereupon being subject to processing operations,
second means for progressively returning said processed workpieces to said tote box upon the further rotation of said frame comprising an inclined planar surface portion connected to the uppermost edge of said curved surface so as to form one continuous surface and extending downwardly and to the right to a region near to said opposite top edge of said tote box, said inclined surface including a trapezoidal section and a pair of raised triangular wing members disposed on opposite edges of said section which also extend downwardly and to the right from said uppermost edge of said curved surface to the vicinity of said opposite top edge of said tote box, thereby to prevent lateral slippage of said workpieces from said inclined surface upon the rotation of said frame.
20. A method for processing workpieces supplied in at least one open container, in a frame of reference for clockwise rotation and in which said container is in an upright position, said method comprising the steps of progressively and gently dumping said workpieces from said container onto a first perforated surface partially enclosing said container by the partial rotation of said container and said surface, said first surface extending upwardly and to left from a region near to one top edge of said container a distance along said surface greater than the width of the opening of said container to a region remote from the opposite top edge of said container,
spreading said workpieces into a less confined area thereby exposing more and different surfaces of said workpieces, progressively returning said workpieces to said container by means of a second surface extending downwardly and to the right from the uppermost end of said first surface to a region near to the opposite top edge of said container.
2]. The method of claim 20 for use in conjunctionwith a carousel apparatus having a plurality of processing stations circumferentially disposed about a center, each station including an open enclosure, said method comprising prior to said dumping step the additional steps of loading at least one of said containers into a cylinder having therein said first and second surfaces for each such container, lifting said loaded cylinder to a height above said enclosures, sequentially rotating said cylinder to each station, lowering said cylinder into said enclosure through its opening, covering said opening, performing said dumping, spreading and subjecting and returning steps at least once at each of said stations.
22. The method of claim 20 including the steps of immersing said container and said first and second surfaces into a processing solution, emersing said container and said surfaces from said solution, subjecting said workpiecesat least to processing vapors and concurrently rotating said container and said surfaces to repeatedly perform said dumping, spreading and returning steps.
23. The method of claim 22 wherein said dumping step is preceded by the step of coupling said container and said surfaces to a conveyor belt for successive translation to a plurality of processing stations, performing at least once at each of said stations said dumping, spreading, subjecting and returning steps.