US2916131A

US2916131A - Article treating apparatus

Info

Publication number: US2916131A
Application number: US597780A
Authority: US
Inventors: Artemas F Holden
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-07-13
Filing date: 1956-07-13
Publication date: 1959-12-08
Anticipated expiration: 1976-12-08

Description

. 8, 195 A. F. HOLDEN ARTICLE TREATING APPARATUS 5 Sheets-Sheet 1 Filed July 13, 1956 INVENTOR'.

Giff/$466 A 1/0 DEN A 7' NRA/l rs Dec. 8, 1959 Filed July A. F. HOLDEN "ARTICLE TREATING APPARATUS 5 Sheets-Sheet 2 SHORT 15-! 46"? Ma Ma J INVENTOR.

1959 A. F. HOLDEN 2,916,131

ARTICLE TREATING APPARATUS Filed July 13, 1956 5 Sheets-Sheet 3 v ll 61/ u- 7 6'74 7a U I v a 801-! ll ea 6' 9 /'fiCC.

J'OUCI INVENTOR.

1959 A. F. HOLDEN 2,916,131

' ARTICLE TREATING APPARATUS Filed July 13, 1956 5 Sheets-Sheet '4 Dec. 8, 1959 A. F. HOLDEN 2,916,131 ARTICLE TREATING APPARATUS Filed July 1a, 1956 5 Sheets-Sheet 5 United States Patent ARTICLE TREATING APPARATUS Artemas F. Holden, Milford, Mich.

Application July 13,.1956, Serial No. 597,780

6 Claims. (Cl. l98'--19) The present invention relates to an article treating apparatus and more particularly to a materialhandling apparatus of the rotary type movable about a fixed center for conveying or otherwise handling articles for subjec tion to a plurality of treating operations at corresponding individual stations located radially of the fixed center in circumferentially spaced relation thereabout.

In the art of treatingmetal or metal articles, as by heat treatment, plating, cleansing, coating, or otherwise treating the articles, the treatment usually involves the im mersion of the article into and the removal of the article from a plurality of baths or other process equipment, as well as the conveying of the articles between the stations. In the conventional material handling equipment comm'onlyutilized in connection with such processes, an extensive, elaborate, and expensive overhead conveyor is utilized; This type of conveyor is not only costly for its initial installation, but it requires a large amount of floor space and overhead space to accommodate the monorail or similar supporting structure. Additionally, elaborate hoist and hoist control mechanism are necessary to this type of installation.

The present invention now proposes a new and novel type of material handling apparatus for use in such processes. The apparatus of the present invention is compact, relatively inexpensive, easily controlled through the use of a simple control circuit for either automatic or manual operation, and the fioor space requirements are considerably reduced.

More particularly, the device of the present invention utilizes a turntable-type base upon which is mounted a plurality of work-supporting arms which extend radially from the base for vertical alignment with a plurality of work stations arranged concentrically about the base. The work is preferably carried by cables or the like extendinglongitudinally of the arms and radially of the base plate so that the work, or a basket or the like containing a number of small articles, may be readily immersed into and removed from the various baths or stations by tensioning or loosening the cables. The cables, in one embodiment of the invention, are controlled. simultaneously by single power actuated mechanism, and in another embodiment of the invention, are individually controlled so as to accommodate variations in the treating time at thevarious stations.

To transfer the material being treated from one station to the next, the superstructure, including the material carrying arms, is merely rotated upon the turntable base. .Various means of rotative locomotion may be utilized, the illustrated embodiment of the invention utilizing a pair of sequentially actuatable fluid pressure cylinders which accurately index the rotatable structure into vertical 'alignment with each of the stations.

' It is, therefore, an important object of the present invention to provide a new and improved article treating apparatus operative to effectuate amulti-station process;

Another important object is the provision of an improved article treating apparatus of the rotatable type disposed upon a turntable base and operable to arcuately convey articles to and between a plurality of work stations.

It is a furtherobject of the present invention to provide an article treating apparatus wherein a plurality of radially extending arms are disposed for rotation about a fixed common center and are provided with means for elevating and lowering, an article disposed at the radially outward ends of the arms, the arms being indexed rotatably to a plurality'of positions in registry with a corresponding plurality of work stations.

Yet another important object is the provision of an article treating apparatus effective for operation to sub.- ject articles to treatment at a plurality of separately disposed work stations and provided with a control system for raising and lowering the articles at each stationand to arcuately convey the articles between stations.

It is a still further. object of this invention to provide an improved article treating apparatus wherein an article to be treated is conveyed circumferentially between a plurality of correspondingly arranged work stations and is lowered at each-station fortreatment and elevated for conveyance to the next station under the control of an automatic control apparatus.

An additional object is the provision of a material handling apparatus for. use in a multi-station treating process.

Other and further objects will be more apparent from the following detailed description of a preferred embodiment of this invention and by reference to the drawings forming a part hereof wherein:

On the drawings: I

Figure 1 is a plan view ofi an article treating apparatus of the present invention utilized. in conjunction with a plurality of circumferentially arranged work stations;

Figure 2 is a sectional view, with parts shown in clef vation, taken along the planes-2 2 of Figure 1;

Figure 3 is a schematic illustration of the electrical control system utilized in conjunction with the apparatus of Figures 1 and 2;

Figure 4 is a schematic representation of the fluid pressure actuated system utilized in-conjunction with the apparatus of Figures 1 andZ and correlated with the electrical control systemof Figure3;

Figure 5 is a plan, view similar to Figure; 1 but illustrating, a modified form of apparatus of the present invention; v

Figure 6. is. a view. similar to. Figure 2v but illustrating the modification of Figure 5; v

Figure 7 is awiring diagram for a manually actuatable control system for the device of Figures 5 and 6; and;

Figure 8 is a schematic view of a fluid pressure actuated mechanism for control by the circuit of Figure 7.

As shown on the drawings:

In Figure 1, reference numeral 10 refers generally to an article treating-apparatus of the present invention.

'In Figures 1 and 2', reference numeral 11 refers to a base plate carrying a plurality of depending rollers or casters 12 operating ,on a circular track 13 which is fixed to the flQor or other supporting structure and which is concentric with the circular base plate 11. The base'plate, is freely rotatable relative to the track 13 and carries a plurality of circumferentially arranged, vertically extending beams 14, which are illustrated as being formed of I sections. Superimposed upon each of the vertical beams 14 to extend generally radially of the base plate 11 are a corresponding number of work-supporting arms 15, the inner ends of the arms. 15 being welded or otherwise joined together at the center and being each braced by an angularly extending diagonal brace 17 joining each of the arms to the corresponding beam 14.

The base plate 11 also carries a central superstructure supporting a central, generally cylindrical guide 18, the

superstructure comprising laterally extending struts 19 joined to the base plate and the guide 18 and secondary struts 19a joined to the struts 19 and to the guide 18. The guide 18 serves to prevent lateral displacement of an actuating mechanism, indicated generally at 20, and including a centrally located fluid pressure cylinder 21 having a vertically upwardly directed actuating rod 22 connected to a circular actuating plate 23 which is disposed Within the guide 18 for movement axially therealong in a vertical direction.

The plate 23 carries a plurality of radially arranged pulleys 24, one such pulley being provided for each arm 15, and the pulleys are each peripherally lapped by a cable 25, one end of which is anchored to the upper inner ends of the arms, as at 26. The first reach of the cable depends from the arms for lapping about the pulleys 24, and then the cable extends, upwardly to be lapped about a pulley 27 carried by a bracket 28 superimposed on the arm. Of course, the arm is apertured, as at28a (Figure 1), to allow passage of the cable therethrough. The cable then extends radially along the length of the arm to be trained about a pulley 29 located at the radial outer end of the arm upon a bracket 30 secured thereto. The terminal end of the cable depending from the pulley 29 is secured to a basket 31 or other work-engaging or workcontaining device. As specifically illustrated, the baskets 31 are formed of wire mesh screen secured to a rigid framework. The arm also carries on the lower side of its outer end a basket guide 32 adapted to snugly receive the basket 31 therein to steady the basket against undesired lateral displacement when the basket is in its fully elevated position, as illustrated in Figure 2.

As best seen in Figure 1, the article handling apparatus is located centrally of a plurality of work stations, including a first station 33 which comprises simply a platform at which the baskets may be loaded or unloaded from the cable 25. A second work station spaced arcuately from the station 33 may suitably comprise a preheat vat or container 34 in which articles in the basket are subjected to heat from a burner, indicated generally at 35. The next station comprises a radiant panel gas furnace, indicated generally at 36, utilized in conjunction with a combustion chamber, indicated at 37. The combustion chamber receives gas or any suitable combustible mixture, as through supply pipes 38, with heated gas from the combustion chamber being conducted through conduits 39 through opposing baffle chambers 40 for heating articles disposed in a basket 31 and lowered into the heating space 41. Exhaust gases are vented through exhaust conduits 42 for removal from the furnace.

The next station comprises a cooling chamber 43 into which the articles are lowered following heating in the furnace 36, the cooling chamber receiving air through a conduit 44, the air being exhausted by a fan 45.

The air transferred through the conduit 44 comes from a hot water spray station, indicated generally at 46, and including a spray ring or nozzle 47 through which hot water 18 introduced onto the articles under pressure generated by a water transferpump 48 which receives water from a hot water tank or station 49. The next succeedmg station (the last treatment station of the process) 1s indicated generally at 50 and merely comprises a tank into which articles contained in the basket 31 are immersed for treatment with a solubleoil to prevent rustmg of the articles upon oxidation induced by the water sprayed thereon at the station 46 and within which the articles were immersed at the station 49.

Thus, it will be seen that the

stations

34, 36, 43, 46, 49, -and 50 comprise a complete heat treatment process whlch artlcles are preheated (at station 34), heated to a hlgh temperature at the radiant panel gas-furnace of station 36, cooled at station43', subjected to a hot water spray at 46, immersed in hot water at 49, and finally coated with a soluble oil for rust-proofing at station 50.

The station 33 serves to both load and unload the basket contents.

By the utilization of the control system illustrated in Figures 3 and 4 of the drawings, the entire process may be automatically carried out. The operation of the control system will now be described.

As indicated in Figure 3 of the drawings, current from a source 51 passes into a pair of

supply lines

52 and 53. Interposed on the supply line 53 is a start button 54 bypassed by holding circuit including relay points 55 actuated by a relay 56. The supply line 57 from the start button 54 is directed to one terminal of a limit switch LS1 which is located, as best seen in Figure 2, upon the basket retainer 32, so that the switch is actuated to its closed position at any time that the basket is in its fully raised position. The limit switch LS1, when closed, directs current through a second limit switch LS2 which is spring biased to a normal position illustrated in solid outline in Figure 3.

The limit switch LS2 is located at one end of a cylinder 58 (Figures 1 and 4) which is adapted to effect radial movement of the apparatus. More specifically, the cylinder 58 is provided with an actuating rod 59 which is ex' tensible to abut one of the plurality of fixed reaction plates 60 interposed on the floor or other stationary element between each station of the process and the base plate 11. Extension of the cylinder 58 will cause its actuating rod 59 to contact the reaction plate 60 causing the cylinder, together with the base plate 11, to turn in a counterclockwise direction, as viewed in-Figure 1. Actually, actuation of the cylinder 58 will carry the base plate circumferentially to an extent equivalent to one half the circumferential distance between adjacent stations, and a second actuating cylinder 61 has an extensible actuating rod 62 which is adapted to abut another one of the reaction plates 60 upon actuation of the cylinder 61 and upon the completion of the stroke of the cylinder 58. This actuation of the cylinder 61 will complete the movement of the base plate to the circumferential extent necessary to superimpose a basket over the next adjacent station.

Also in Figure 1, reference numeral 63 refers generally to a stop mechanism comprising a cylinder 64 having a fluid pressure actuated stop rod 65 operable in a manner to be hereinafter described to prevent movement of the base plate prior to actuation of the

cylinders

58 and 61 and also to accurately index the arms into vertical alignment with the process stations.

Returning to the control diagram of Figure 3, the limit switch LS2 is located at the radial outward end of the cylinder 58, so as to be actuated by the cylinder piston upon full stroke movement of'the actuating rod 59. This actuation of the limit switch LS2 will move it to its dotted line position as shown in Figure 3. When limit switch LS1 has been actuated, and limit switch LS2 occupies its solid line position in Figure 3, then a circuit ls completed to solenoids SOL1 and SOLZ. Referring now to Figure 4 of the drawings, it will be seen that solenoid SOL1 is a repulsion type and actuates the valve posed in an air supply line 68 which is connected to an accumulator 69 receiving air pressure from'a source (not shown). The four-way valve 67 is provided with a passage 67a adapted to connect the supply line 68 to a lme ,70 connected with the cylinder 58 and adapted to actuate the cylinder in such manner as to extend the rod 59 thereof into abutment with the reaction plate 66.

. The line 70 also supplies air under pressure to the stop cylinder 64 in such manner as to retract the stop rod 65 thereof against the force of a return spring 71. The solenoid SOLl is a repulsion type and actuates the valve 67 to its illustrated position in Figure 4 against the pressure of a compression spring 72 which normally urges the valve 67 to the left so as to align a vent passage 67b with atmospheric pressure,

Thus, when limit switch LS2 is actuated, as upon comder 58, solenoid SOLl is 'deenergized and .the spring 72 moves thevalvebody 67 to its venting position so that the return spring 73 of the cylinder 58 will return or retract the actuating rod 59. Simultaneously,.the cylinder 67 will be vented to the atmosphere so that the return spring 71 thereof will extend the piston rod 65 to its stop position, as illustrated in Figure l.

Solenoid SOL2 is of the retraction type and servesto move a second valve body 74 to the position illustrated in Figure 4 at which a vent passage 74a in the valve body 74 is aligned with the atmosphere through a vent. This accommodates movement of the actuating rod 62 of the cylinder 61 to its fully retracted position under the in fluence of the return spring 75.

Upon movement of the limit switch LS2 to its dotted line position, as upon full extended actuation of the cylinder rod 59, solenoids SOLl and SOL2 are deenergized and solenoid SOL3 is energized. Solenoid SOL3 is. of the attraction type and pulls the valve body 74 to the right so as to align the air pressure-passage 74b thereof with a branch supply line 68a and with an vai-r supply line 68b for the cylinder 61. Thus, the cylinder 61 is actuated to the right to extend the actuating rod 62 thereof into contact with the adjacentreaction plate 60, thereby moving the turntable to that extent necessary to cause abutment of the stop rod 65 with the adjacent edge of the next reaction plate 60.

Limit switch LS3 is located upon an upstanding post 76 projecting upwardly from the load and unload station '33. The limit switch LS3 is abuttable with a switch actuation arm 77 carried by each of the upstanding beams 14. Thus, the limit switch LS3 is actuated each time thatthe arms are vertically aligned with the process stations. Closure of the limit switch LS3 will actuate a solenoid SOLS, so long as the relay points CR1 are closed. Since the relay points CR1 are normally closed, we shall consider-that solenoid SOLS has been actuated.

From Figure 4, it will be seen that solenoid SOLS is of the attraction type and actuates to the left a valve body 78, so that a vent passage 78a therein is in communication with the cylinder 21 through a cylinder supply line 79. Thus, the cylinder 21 is vented to the atmospheric pressure and the weight of the basket 31 will allow the basket to travel downwardly to the appropriate process stations. Such downward movement of the baskets will, through the cables 25, c ause vertical extension of the rod 22 of the cylinder 21 until such time as the piston on the rod 22 contacts the limit switch LS4 to close the same. Closing of the limit switch LS4 will actuate circuit relay CR2, the points of which, indicated at 80, are interposed between the electrical supply 57 and a timer 81. The timer is thus actuated for operation and upon completion of the timer interval, the timer will actuate relay CR1. This relay opens the contacts CR1 to de-energize solenoid SOLS, even though limit switch LS3 is still actuated. Further, the timer will energize solenoid SOL6 which, as illustrated in Figure 4, is of the attraction type and effective to align passage 78b with the cylinder supply line 74 and a branch source supply line 680. Fluid under pressure is best effective toactuate the cylinder 21 to retract the piston 22 which, through the cable 25, will elevate the basket 31. Actuation of the cylinder 21 will also allow limit switch LS4 to open, thus de-energizing relay CR2 opening relay contacts 80 and de-energizingthe timer 81. When the baskets 3'1 have been elevated to an extent sufiicient to actuate the limit switch LS1, this switch will be closed and the previously described cycle will be repeated.

T he embodiments of Figures 5 and 6 In that embodiment of the invention as illustrated in Figures 5, 6, 7 and 8, a form of apparatus generally similar to that hereinbefore disclosed is utilized. However,

two important difierences will be readily evident to those skilled in theart. First, the modified embodiment of the invention, asbest shown in Figure 5, utilizes a load and unload station intermediate a pair of work stations. Secondly, the device is provided with a non-automatic, manually operable control system of a type which would be readily adapted to that form of the invention shown in Figures 1 4, if such were necessary or desired.

More particularly, in Figure 5 it will be seen that the apparatus is of the type utilizable in conjunction with six operating stations which are denoted generally-by cylindrical vats or containers indicated by referencenumeralls 100405, inclusive. These six stations may comprise any desired type=of apparatus for carrying out a sequential article treating process, such .as aphosphating process in which case the tank or station will be a metal screening tank heated for example from 175 degrees to 200 degrees 'F., station .101 will be a cold rinse tankwith circulating .water flow',.station 102 will. be an alloy.steel tank containing a heated phosphating solution, station 103 will be a cold rinse tank identical with station 101, station 104 willbe a-heated chromic acid tank, and the final station 105 will be a tankcontaining a water-displacing rust inhibiting oil.

A load and unload station106 is located generallyintermediate the initial station .100 and the final station 105. The station is thus conveniently located for both loading articles to be treated and for unloading articles previously treated. Inasmuch as the station 106 is intermediate. the two

stations

105 and 100, the indexing means must be operated in such manner that articles maybe handled at this station, as well as at the working stations.

As illustrated in Figures 5 and 6, the apparatus is generally similar to that heretofore. described and comprises a base plate 110 mounted forrotary movement upon a track 111. The base plate 110 is provided with a plurality of vertically extending beams 112 which support superimposed laterally extending supporting arms 1 13 cross spaced to the beam and secured thereto as hereinbefore described. The arms each carry at theirouter ends basket guides 14, and a pair of laterally spaced pulleys 115 are provided, all as heretofore described. Lapped about the pulleys 115 is a cable 116 which .carries at its free outer ends an article containing basket 1-17, and-the pulley is secured at its inner end to the actuating rod 117 of a cylinder 118. It will be noted that a separate cylinder 118 is provided for each of the cables 116, so that each basket 117 may be individually raised and lowered in accordance withthe actuation of its individual cylinder. For clarity of illustration, the cylinders are individually identified with alphabetical suflixes so that the lift cylinders include cylinders 118a through 118 (Figure 8).

The base plate 110 carries a generally centrally located hydraulic pump 119 and a sump 120, the pump being driven'by suitable means, as for example electrically, so as to supply a source of pressure of hydraulic fluid for the actuation of the cylinders 118a through 118 Thebase plate 110 is indexed rotationally by the utiliza tion of a pair of sequentially actuated

cylinders

120 and 12 1, the pistons of which react against fixed reaction plates 122, as heretofore described in connection with the earlier embodiment ofthe invention.

Each of the basket guides 114 carries a limit switch identified generically as switch 5-2 and individually as switches 82-1, 82-2, 82-3, 824, S25, S26 (Figure 7). Additionally, a switch S1 is located at one of the work stations, as for example atthe work station 101 in Figure 6, while an additional switch 8-3 is located at the load and unload station 106'. These last two switches, S-1 and 8-3, are adapted to be actuated by a laterally projecting switch arm 123 which is carried by each of the vertically extending posts 112 and secured thereto, as through carrying arms 124.

Inasmuch as current is to be supplied to each of the limit switches S2-1 through 52-6 and to other mechanism j to be hereinafter more fully described and associated with the individual cylinders use-11st, the switch actuating arm 123 may desirably comprise a bus bar which contacts a conductor at each of the process stations, thus avoiding the necessity of transmitting a large amount of current to the rotatable turntable 1 10 through the conventional slip rings or the like; p ,I V I The operation of the device illustrated in Figures Sand 6 is quite similar to that heretofore described in connection with Figures 1 and 2, the control of the apparatus being'effected through the electrical wiring diagram of Figure 7 and the hydraulic control mechanism diagrammatically illustrated in Figure 8'.

In Figure 7, electrical power from a direct current source 130 is introduced through

lines

131 and 132 to control the cylinders 118a through 118] through a push button denoted raise which is provided with a holding circuit comprising the relay R1 and its points 133. A second pair of normally closed relay points 134 in the .holding circuit is. under the control of the second relay R2 which is actuated through the limit switch S1 located at the operating station 101, as heretofore described. When the limit switch 8-1 is closed, the relay contact points 134 are opened and the holding circuit is broken. The holding circuit supplies current toa plurality of individual manually actuated switches arranged in parallel and indicated at load or L1, L2, L3, L4, L5 and L6, refern'ng to each of the individual cylinders 118a through 1181i The solenoid windings control

individual valves

135a, 135b, 135e, 135d, 135e and 135] which control the respective cylinders 118a through 118 as illustrated in Figure 8. The respective valves are substantially identical with that illustrated in Figure 4 and indicated thereon by reference numeral 67. The solenoids Vl-V6 actuate the valves to connect the individual cylinders to a hydraulic pressure line 136 which is connected to the pump 119, or other suitable sources of hydraulic pressure. When the solenoids are de-energized, the valves 135a-135f are deenergized and are spring urged to a venting position at which the individual cylinders are connected to the sump. The cylinders 118a through 118i are single acting with a spring return, so that venting of the cylinders to the sump through the valves 135a-135f will allow the spring return of the cylinder to urge the cylinder to its extended position at which the basket 117 associated therewith will be lowered at either the load and unload station 106 or at one of the process stations 100105. Of course, the weight of the basket and contents will aid in effecting movement of the cylinders to their extended positions.

Thus, when the manually actuated switches L1L6 are opened individually and the associated solenoids V1-V6, inclusive, are de-energized, the associated load basket 117 will be lowered. It will be noted that the lowering of the baskets because of de-energization of the solenoids Vl-V6, inclusive, is accomplished simultaneously at each of the loading stations, since closure of the limit switch 8-1 will de-energize the holding circuit. Additionally, this de-energization of the individual solenoids can occur manually by opening the load switches L1-L6, individual- 1y.

The

cylinders

120 and 121, which operate sequentially to rotationally index the turntable 110, are energized through the series of limit switches S21 through 52-6 'which are located at the basket guides 114. It will be noted that these switches are connected in series, so that vall of the switches must be closed simultaneously, that is all of the baskets must be in a raised position, before either one of the cylinders 120 or .121 can be energized. The cylinder 120 is initially actuated (to index the complete unit from alignment with the process stations to an intermediate position in alignment with the load and unload station 106) by closure of the manual switch M1 which will actuate the valve solenoid V7 so as to move limit switch 54 located at station 106 is in its normally closed position. When the appropriate one of the arms 113 comes into alignment with the limit switch 5-3, this switch will-be opened and the solenoid V7 will be deenergized 'so thatithe counter acting spring can move the valve 137 to ventposition, as illustrated in Figure 8. T0 actuate the cylinder 121 it is only necessary to manually close the switch M2 which will energize the solenoid winding V8 to the valve 138 controlling actuation of the cylinder. Also in the circuit for the winding V8 is additional contact to the limit switch S-l located at the process station so that the cylinder 121 will be deenergized when the contact point of the switch is actuated by the switch arm 123.

From the foregoing description of the control apparatus, it will be readily appreciated that this embodiment of the present invention is semi-automatic in operation. Let us assume that the apparatus is in its condition as illustrated in Figure 5 wherein the baskets .117 have been lowered into and remain at the process stations 100-105 until the process at that station has been completed. Next, the raise button is depressed to energize the solenoid windings V1V6, venting the cylinders 113a118f to the fluid pressure line 136. All of the baskets 117 will be raised. When the baskets are raised and the limit switches S2l through S2-6 all have been closed, closure of the manual switch M1 will index the turntable rotationally until the limit switch S3 at the load and unload station 106 has been actuated to break the circuit for the valve winding V7. Next, upon opening the manual switch to Load 1, the solenoid winding V1 will be de-energized so that this one basket, assumed to be in vertical alignment with station 106, is lowered at the load and unload station. The remainder of the baskets remain elevated.

' Upon unloading the articles in the basket and reloading it with articles to be processed, the switch Load 1 is closed again to energize cylinder 118a for elevating the work load. As soon as the corresponding limit switch S2-1 has been closed, the switch M2 may be actuated 'manually to energize the solenoid winding V8 which will actuate the cylinder 121 index the turntable to the next process station.

After this station has been reached the limit switch S1 will be actuated, the cylinder 121 will be de-energized, and all of the baskets will be lowered by opening of the relay contact points 134 to de-energize all of the valves V1V6. This cycle may be repeated following the com pletion of the next process step.

Obviously, timing means may be incorporated in the circuit of Figure 7 to elevate all of the baskets following the termination of the process cycle, or individual timers may be utilized in connection with the individual cylinders 118a-118f, inclusive, to provide an individual timing control over the various process steps.

Thus, it will be seen that the present invention provides a new and novel process apparatus which is par ticularly useful in connection with metal treating processes. The device provides a material handling apparatus for conveying various articles through a multi-station process, under either automatic or manual control. The advantages in flexibility of control, ease of material handling, the reduction in the required floor space, and the inexpensive apparatus required, will be readily evident to those skilled in the art.

While preferred embodiments have been described above in detail, it will be understood that numerous modifications might be resorted to without departing from the scope of my invention as defined in the following claims.

I claim:

1. In an article treating apparatus in which the articles are subjected to treatment at a plurality of peripherally spaced work stations, a turntable located centrally of said stations, a superstructure supported by said turntable and having radial arms, spaced guide elements on the arms, cables lapping said guide elements, work retaining means carried by said cables in aligned relation to said work stations, the number of arms, cables and retaining means corresponding to the number of work stations, fluid pressure actuated means for tensioning said cables to elevate said retaining means relative to said work stations, and a plurality of sequentially operable actuating means for indexing said retaining means from alignment with specific work stations into alignment with the next adjacent work stations, any one of said actuating means alone being ineffective to index the retaining means to said next adjacent work station.

2. In an article treating apparatus, a freely rotatable constant level superstructure including radial arms, means for suspending, elevating and lowering a plurality of article retaining elements from said superstructure arms for vertical registration with a plurality of work stations arranged peripherally thereabout, means for indexing said superstructure rotationally to move said elements when elevated into registration with others of said work stations, a control system for said indexing and suspending means including means for initiating indexing movement when the elements are elevated, and means for halting indexing movement when the elements are in registry with said others of said work stations.

3. In an article treating apparatus, a freely rotatable turntable, a superstructure including radial arms carried by said turntable for constant level rotation therewith, means for suspending a plurality of article retaining elements from said superstructure arms for vertical registration with a plurality of work stations arranged peripherally about said turntable, means for raising and lowering said elements relative to said arms, means for indexing said turntable rotationally to move said elements into registration with others of said work stations, and means actuated by the lowering of said elements at said work stations for initiating a treatment time cycle.

4. In an article treating apparatus in which the articles are subjected to treatment at a plurality of peripherally spaced work stations and a load-unload station intermediate a pair of said Work stations, a turntable located centrally of said stations, a superstructure supported by said turntable and having radial arms, spaced guide elements on the arms, cables lapping said guide elements, work retaining means carried by said cables in aligned relation to said work stations, the number of arms, cables'and retaining means corresponding to the number of work stations, fluid pressure actuated means for tensioning said cables to elevate said retaining means, and a plurality of sequentially operable actuating means for indexing said retaining means from alignment with specific work stations into alignment with the next adjacent work stations, any one of said actuating means alone being ineffective to index the retaining means to said next adjacent work station and the initially operable one of said actuating means being efiective alone to index the retaining means into alignment with the load-unload station.

5. In an article treating apparatus, a freely rotatable turntable, a superstructure including radial arms carried by said turntable for constant level rotation therewith, means for supporting a plurality of article retaining ele ments from said superstructure arms for vertical registration with an equivalent number of work stations arranged peripherally about said turntable, means for elevating and lowering said elements relative to said arms, means for indexingsaid turntable rotationally to move said elements into registration with others of said work stations, and inhibiting means preventing indexing of the turntable until all 'of said elements are elevated.

6. In an article treating apparatus in which the articles are subjected to treatment at a plurality of peripherally spaced work stations, a turntable located centrally of said stations, a superstructure supported by said turntable and having radial arms, spaced guide elements on the arms, cables lapping said guide elements, work retaining means carried by said cables in aligned relation to said work stations, the number of arms, cables and retaining means corresponding to the number of Work stations, fluid pressure actuated means for tensioning said cables to elevate said retaining means, and a pair of sequentially operable fluid pressure actuated cylinders for indexing said retaining means from alignment with specific work stations into alignment with the next adjacent work stations, either one of said actuating means alone being ineffective to index the retaining means to said next adjacent work station, and the second-acting of said cylinders being actuated only after substantial completion of the stroke of the first-acting of said cylinders.

References Cited in the file of this patent UNITED STATES PATENTS 22,662 Mansley Jan. 18, 9 1,359,225 Bossert Nov. 16, 1920 2,562,506 Petersen h.-. July 31, 1951 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 2,916,131 December 8, 1959 temes F Holden It is harsh? certified that error appears in the -printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 27, for "between the" read between these column 4, line 59, strike out "is a repulsion type and ectuatee the valve" and h insert instead controls a four way air valve 67 intercolumn 6, line 41,- for "guides 14'' read guides 114 Signed and sealed this 31st day of May 1960.,

(SEAL) Attest: I

KARL H0 AXLINE Attesting ()fficer ROBERT C. WATSON Commissioner of Patents