US2536720A

US2536720A - Metal coating apparatus

Info

Publication number: US2536720A
Application number: US657537A
Authority: US
Inventors: Jr Frederick C Brightly
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-03-27
Filing date: 1946-03-27
Publication date: 1951-01-02
Anticipated expiration: 1968-01-02

Description

Jan. 2, 1951 F. c. BRIGHTLY, JR 2,536,720

- METAL COATING APPARATUS Filed March 2'7, 1946 5 Sheets-Sheet l mm F'redgrick C. 7 BmghtIq,cJr. MW @350 W4 4 4p.

F. c. BRIGHTLY, JR 2,536,720

METAL COATING APPARATUS Filed March 27, 1946 '5 Sheets$heet 2 w Z i T Q E I Frederick c. Irightlumjr. d @4400, 62;, MM K 5 Sheets-Sheet I5 \W b M. m

MEMO

ghHu, Jr'. W a 014 b.

(fl-mommy Jan. 2, 1951 F. c. BRIGHTLY, JR

METAL comma APPARATUS Filed March 27. 1946 Frederiqk C. Bri

1951 c. BRIGHTLY, JR 5,

METAL comma APPARATUS Filed marchz'r, 1946 5 Sheets-Sheet 4 Frederick C. BrighUq,Jv. 2 28 44%, @w, W k

' (flTTonuNEY Jan. 2, 1951 Filed March 27, 1946 F. c. BRIGHTLY, JR

METAL COATING APPARATUS 5 Sheets-Sheet 5 III II WW Frederick- C.

Brighflmdr. U. I MM. 015%..

TTOQ-NEW Patented Jan. 2, 1951 UNITED STATES. PATENT OFFICE METAL COATING APPARATUS Frederick o. Brightly, Jr., Oak Park, 111.

Application March 27, 1946, Serial No. 657,537

5 Claims. (Cl. 212-131) The present invention relates generally to improvements in metal coating apparatus, and has particular reference to a new and improved apparatus for coating metals'by the hot dip process, as, for example, for galvanizing, tinning and lead coating.

One of the primary objects of the present invention is to provide a, novel metal coating apparatus which greatly reduces the arduous manual labor that is normally required, and which affords a uniform and flexible control of the operation.

Another object is to provide a new and improved metal coating apparatus in which the material to be galvanized is translated from station to station, and elevated and lowered by power means, thereby permitting the use of large baskets for handling the material, and utilization Another object is to provide a new and imr the electrical operating and control circuits of proved metal coating apparatus which carries out automatically those steps of the operation that are most hazardous when performed manually, which greatly reduces the number of operators or attendants that are required, and which eliminates the human factor as a cause of possible error in passing the material through the hot coating bath.

A further and more specific object is to provide a novel metal coating apparatus which comprises a trolley running on a closed overhead rail circuit and driven by a variable-speed electric motor, and a hoist on the trolley for carrying the work basket and operable by a reversible variable-speed electric motor to elevate and lower proved metal coating apparatusof the foregoing Further objects and advantages will become apparent as the description proceeds.

In the accompanying drawings,

Figure 1 is a plan view of a galvanizing apparatus embodying the features of my invention.

Fig. 2 is an elevational View, partially in vertical section, of the operating run of the apparatus. Fig. 3 is a transverse vertical section, on an enlarged scale, taken along line 3-3 of Fig. 1, and illustrating the basket handling mechanism.

Fig. 4 is a fragmentary detail view, partially in longitudinal section and on a still larger scale, of one of a plurality of parallel segmental trolley wires or conductors forming part of the electrical control circuits of the apparatus.

Fig. 5 is a fragmentary perspective view, with the elements shown in exploded relation, of one of. the insulating connections for joining the contiguous ends of the various segments of the trolley wires.

Fig. 6 is a. transverse vertical sectional view taken along line 6-6 of Fig. 4.

Fig. 7 is an enlarged side elevational view of the trolley and hoist assembly.

Fig. 8 is a diagrammatic representation of the apparatus.

While the invention is susceptible of various modifications and alternative constructions, I

I have shown in the drawings and will herein describe in detail several embodiments, but it is to be understood that I do not thereby intend to limit the invention to the specific forms disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Referring more particularly to the drawings, the metal coating or galvanizing apparatus, constituting the exemplary embodiment of the present invention, comprises various operating units for treating the material sequentially in the character in which the direction of rotation of lowing along the supporting rail circuit.

successive steps of a hotdip galvanizing process. 'These operating units are arranged in series alignment, and may be conventional in type and construction. In the present instance, the units 7, comprise a dryer ID, a galvanizing kettle I l a cen- 1 trifuge l2, a quenching tank l3, and, if desired, an

inspection table or conveyor M. The details of the operating units I0 to It, per se, form no part of thepresent invention, and hence are described "only in general respects to facilitate understand- J ing of their functions in the apparatus. Preferably, all of the units are mounted at suitable levels on a solid foundation [5.

The dryer Ill, in the form shown, comprises a horizontal mesh conveyor l6, preferably of Monel metal, driven by an electric motor ii, a heating element l8 over the conveyor and preferably consisting of a steam heat radiator, and a series of overhead fans !9 for directing blasts of hot air from the heating element downwardly through the conveyor tunnel. The material to be galvanized, which may consist at different times of duplicate workpieces of Widely varying shapes, and sizes, is customarily cleaned in an acid pickling bath and pre-dipped in a flux sourtion, and is then placed on the inlet end of the conveyor I to be dried. The hot air blasts in the dryer it serve to remove surface moisture from the work pieces preparatory to the galvanizing operation.

The galvanizing kettle H may be of any suitable type, and in the present instance comprises a long rectangular tank 20 supported on a depressed portion of the foundation l5 at a lower level than the dryer Id, and having compartments 2| and 22 respectively in opposite 'end portions defined by a stopper or dam 23 and in 'intercommunication beneath the latter. The first compartment 21 normally contains 'a galvanizing bath 24 of zinc covered with'a layer 'or blanket of a suitable fluXing agent, such, for example, as sal ammoniac or 'zinc ammonium chloride. The second compartmentZZ normally contains a clear zinc bath 25, the stopper 23projecting downwardly into the zinc sulficiently to confine the layer of flux to the surface of the bath 24. Any suitable heating means, represented at 26, may be provided in the lower portion of the kettle II to maintain the zinc in a molten state. After the removal of moisture in the dryer ID, the material or work pieces to be galvanized are taken from the discharge end of the conveyor [6, and loaded into a suitable basket 21 to facilitate handling in the subse uent steps of them:- eration. The baskets for this purpose are usually cylindrical in shape, open at the top, provided with a bail 28, and formed with apertures in the peripheral and bottom walls to permit free passage therethrough of the fluid zinc for surface contact with the work pieces. It will be .under- .stood that after leaving the dryer ii], .the loaded basket '27 is transferred to the galvanizing kettle .H, and immersed for predetermined periods of time first in the bath 24 and then in the bath 25 in successive dipping operations. It has been customary heretofore to transport the basket and to 'li'ftit into and out of various operating units by manual labor, thus. entailing arduous work under adverse conditions necessitating frequent shutdowns and limiting the size of basket that can be used.

The rate of speed .at which the basket 2 is dipped or immersed in the first zinc bath .24 should be socontrolledthat any residual moisture .still on or in the work pieces will not becarried downwardly below the surface layer of flux into the the metallic zinc, but will be drivenoff by the heat 'of the flux. If entrained moisture were to be carried into the metallic zinc, it would be converted suddenly and violently into superheated steam which might cause actual eruption of zinc and :fiux from the kettle :l l, and thus result .in -loss :of :these materials and in injury to any operator or bystander. Such -conditionisal-ways a possibility due to human errors .if immersion is effected-manually.

To obtain both efficientand proper coating of the work pieces with zinc, it is important that 4 after full immersion of the loaded basket 2'! in the first bath 24, the basket moved along the bath at such a rate of speed that the work pieces will have been heated to the temperature of the Zinc by the time the basket reaches the discharge end of the compartment 2|. Such equalization of temperature is necessary to effect proper galvanizing. The time required must be varied .in accordance with the character and condition of the work pieces, and depends for example on the size, shape, thickness, and composition of the material. Here again, if translation of the basket along the bath is effected manua'lly, the element of human error in judging the time of immersion may result in nonuniform and unsatisfactory galvanizing.

The centrifuge 12 may be of any suitable construction, and in the present instance is shown as comprising a spinner 29 enclosed within a housing 30 and adapted to receive the loaded basket 21 after removal from the bath 25. The spinner 29 is rigidly supported on the upper end of a vertical drive shaft 3| connected through 'a clutch-controlled power transmission 32 to an electric drive'motor 33. When the basket 21 is placed in the centrifuge I3, it is whirled or rotated "at a high rate of speed, and the resulting centrifugal force serves to throw off any excess zinc and zinc drippings from the basket and contents.

After having been centrifuged, the basket 2-! containing the now galvanized workpieces is lowered into a dumping frame l3a in the quenchtank 13, and the work pieces dumped into a hopper 13b from which 'they'fall into a quenching bath, such as water. The hopper I312 is :automatically operable by a discharge mechanism 34 for transferring the finished work pieces :onto the inspection table -'or conveyor 14, or to any other suitable conveyance.

The present invention resides primarily in the provision of novel power operated'means for conveying the loaded basket 21 from the dryer I0 along'the line of operation,'and, at predetermined points in the path of travel, 'liftingand lowering the basket'so as 'to transfer it successively to the zinc baths 2'4 and '25, the centrifuge I2 and the quenching tank I 3, and when emptied back to the initial loading station. The controls "for the :powermeans are subject to graduation and selec- .tive adjustment so as to provide in each individual instance the desired rate of speed'forele- :vating, lowering, and translating the basket. :In the present instance, the controls-are arranged for :manual actuation at the loading, :centrifuging and quenching stations, and for automatic actuation during the galvanizingstepsand:during therapid'return of the empty basket 'to'the initial starting position. Consequently, the immersion of the work pieces in the zinc .baths is accurately timed to insure efficient and reliable galvanizing over a wide range of operating requirements.

In the preferred embodiment of the invention, the conveying apparatus comprises a wheeled carriage or trolley 35 running on an overhead rail or track 36, and adapted to be driven b a variable-speed'electricmotor'31 carried therewith.

Supported on'the trolley 35 for movement'therewith is a 'hoist'38 having a drum 39 operable by 'a'reversible variable-speed electric motor 40, and serving through asuspension cable 4| to elevate and lower asuitable book 42 adapted to engage the bail 2B of the basket '21.

The monorai136 maybe 01' any suitable form,

Y closed within the case 62.

alisman and extended to define any desired path of travel "providing a run along the various operating units of the galvanizing apparatus. Preferably,the

monorail 36 is in the form of a continuous elon- 'units ll, l2, I3 and I 4, and a return run from the unit l4 along the other side back to the starting point. In sectional form, the rai1 36 may be of I-beam structure having upper and

lower side flanges

44 and 45. A plurality of hanger members 46, located at regularly spaced points about the rail circuit, are rigidly connected at their lower ends to the upper flanges 46 of the rail 36, and adapted to be connected at their upper ends "to a suitable overhead support, such as root trusses or the like (not shown).

A pluralit of bus bars or conductors are supported from and extend along opposite sides of the rail 36 for supplying current to the motors '31 and 48. In the present instance, six of such bus bars 41,48, 49, 58, and 52 are provided,

the two

bars

41 and 48 being disposed along the 'outside of the rail 36, and adapted to supply current under selective voltage control for the trolley motor 31, and the remaining four

bars

49, 59, 5i and 52 extending along the inner side of the rail :and being adapted to supply current reversibly and also under selective voltage control for the" hoist motor 46. The bus bars 41 to 52 preferably are cylindrical in form to constitute trolley wires supported for rolling contact with grooved trolley wheels 53 to 58 on the carriag 35. To provide suitable supporting means for the bus bars 41- to 52, a plurality of transverse angle bars 59 extend across the top of the rail 36 at appropri- 'ately spaced points along the rail circuit, and are rigidly secured intermediate their ends to the upper rail flanges 44. Preferably, the outer ends of the bars 59 are additionally connected by inclined brace members 66 to the rail 36. The bus bars 41 to 52 are individually connected in suspended relation to the underside of each of the transverse bars 59 by means of stand-01f insulators 6|.

The trolley or carriage 35, in its preferred construction, comprises a suitable frame or case 62 having spaced bearing housings 63 at opposite sides of the rail 36. Two pairs of flanged wheels,

64 are fixed on shafts 65 journalled in the bearing housing 63, and are in rolling engagement with the upper surfaces of the lower flanges 45 of the rail 36 to support the trolley 35 in suspended position. The drive motor 31 is connected through a suitable power transmission to the two wheels 64 at one side of the rail to roll the trolley 35 along the rail at selective predetermined rates of speed. More particularly, the m0- tor 31 has an armature shaft 66 connected through a belt 61 and pulleys 61a and 61b to a worm shaft 68a. A worm 68 on the shaft 68a meshes with a worm wheel 69 .on a shaft 69a connected through a link chain and sprockets 69b 'to a shaft in turn connected through two sets- 'of bevel gears 1| and gears lid in one of the bearing housings 63 respectively to the related wheel shafts 65. The motor 31 and all mechanical elements of the power transmission are enstance, the wheels 53 to 58 arerotatabl -jour-e i0 along the track 36. The lower end of each arm 'is provided with a lug Bid for attachment of a =m0tor lead wire. The arms 14 and 15. are connected through electric lead wires or

lines

82 and 83 in parallel across the armature 84 and field 85 of th motor '31. In the case of the hoist motor 49, the

arms

16 and 11 are connected through lines 86 .and -81 to opposite ends of the field 88, and the arms 18 and 19 are connected to lines 89 and 99 adapted i to be connected reversibly through a limit switch 9| to opposite sides of the armature 92.

To control theespeed of operation of the

motors

31 and 48 along or at different sections of the rail circuit, the various bus bars41 to 52, although 2'5 in the form of continuous trolley wires, are each divided-into a series of insulated electrical segments, and certain related segments are connected in pairs through individual circuits to a "suitable source of electrical energy so as to permit of independent voltage control. The contiguous ends of the series of conductor segments in each trolley wire may be mechanicall connected in any suitable manner afiording electrical insu- "lation. The segments are made of a conducting material, such as copper tubing. As shown in 'Figs. 4 to 6, the ends of the segments are separated by a cylindrical spacer 93 made of a suitable insulating material, and having the same 1 outside diameter as the segments so as to present it) a smooth and uninterrupted connection over which the associated contact wheel can roll from 1 one segment to the other. The spacer 93 is formed at opposite ends with reduced cylindrical pilot extensions 93a extending snugly into the is; open bores in the contiguous ends of the conductor segments to maintain the elements in axial -alignment. The upper side of the spacer 93.v is formed with a longitudinal rib 94 coextensive in length therewith. Opposite ends of the rib .94 so "are fitted into slots 95 formed in the upper sides 1 of the conductor segments. To secure the various 'elements in rigid assembly, suitable metal clamp plates 96 are bolted against opposite sides of the end portions of the rib 94, and are formed with arcuate flanges 91 welded to the segments along 1 opposite sides of the slots 95. The plates 96 afford .a convenient means for the attachment of elec trical lead wires to the segments.

The number and lengths of the conductor seggo ments are determined b the specific operations to be performed in the galvanizing process. Considering first the travel of the trolley carriage 35,

vtrolley wires

41 and 48 are interrupted at five 5 points a to e along the operating side of the loop 35101 circuit to provide insulated segments a-b,

--b-c, c-d, de, and e-a. The first pair of segments 01-19 are located at the loading station 93 adjacent the discharge end of the dryer [9, the .point a being the starting point of each operating 7 cycle. These segments are normally disconnected from the source of electric current, but are adapted to be connected through manual control whenever the trolley 35, with a loaded basket-of work pieces suspended on the hook 42, is to. be started through the cycle. Electric current; .is

atom-rm adapted to be supplied to the segments s'a-b .irom main lines 88 and 99 through master s-switch elements I and a normally open control switch #00 adapted to be closed :by means of .a hand actuator 1| 02, the circuit being from main line -98 through switch :element 100, line 1:03,:adjustable rheostat I04, and line I05, to one segment-ab, and from main line -99 through switch element 1:00,:line I06, control switch I01 and .line I01 to the other segment 11-4).

The second :pair of segments b -c extend between the dryer I0 and the galvanizing kettle IrI, a-nd are constantly energized, the eonnectingrcirunits being ifrom main line 98, through :master switch :element 100 and .line 1 08 to one of the segments, and .from mainline 99 through master switch element I00, line 109,, adjustable rheostat H0, and line "III to the other of the segments. "The -rhe'ostats I04 and I'll] are adjustable to vary the speed of the motor 31., and preterablyare set to move the trolley 35 at a comparativel fast of speed. .In starting the operation, the switch 101 is closed and is held closed until the

trolley wheels

53 and 54 pass from the segments Irb to the segments -b--o, the latter automati- *cally taking over control to effect continued -move 'mentof the trolley '35.

fIhe third lpair :of segments :c-fd extend over the galvanizing kettle I I and alsoare constantly energized, the connecting circuits being from :main line :98 through (master switch element 100, and .line II2 to one of :the segments, and from 11min iline *90 through Lmaster switch element I 00, line 1 13, adjustable .rheosta't H4 and "line -I-I5 to the'other 0f the segments. As the trolley wheels -53 'and S'A pass from the segments b-fc to thesegments c-d, travel 'of the trolley 35 is continued automatically but at a rate of speed :rleterrn-ined by the setting of the rheostat :II- l. Along this section or the rail circuit, the work basket is immersed :in the galvanizing kettle and moved :slowly therethrough at a, rate providing :sufiicient time for the work 51318085 to attain the temperature 'of the zinc bath. Consequently, the rheostat H0 is adjusted to provide a 'commensurately low voltage, and the adjustment may be varied in :accordance with the requirements of the work "pieces, which are determined by such factors as size, :shape, thickness and composition.

The fourth pair of segments d-e extend from the galvanizing ketfle II along the centrifuge I2 and quenching tank I3, and are normally'dewnergized but adapted .for :energiza-tion through manual "control. The connecting circuits "are from mainline 58 through master'switc'h element -=I00,?1ine I'IB, rheosta't II! and Eline -I'If8 to one of the segments, and from main .line '99 through master switch element 100, I lin III'a, .norma'lly opencontrol switch I Isa, and line I I9 'to'the'other segment. The control switch II-8a adapted to be closed by means of a hand operator :I20. Tipon movement of the trolley wheels 53 and '54 :from the segments -c-d to the segments d, the trolley 35 will come to rest unless the control switch IIfia is closed. Consequently, the trolley 33 can be-moved into position at an point along the segments d-e, as, 'for example, into position over the centrifuge I2 and subsequentlybver the quenching bath I3, b manually closin the control switch I I8a and keeping it closed until the desired movement has been effected.

The fifth pair of segments e-a -'extend from the quenching tank I3 around the remaining 1portion=of the rail circuit back 'to the starting point a, and are constantly energized, the conmeeting circuits being .from .main line -98, through master switch element I00, and .line .12] to one of the segments, andfrom main line 99., through master switch element I00, line I22, adjustable -rheostat 1-23 and line I24 to the other segment. These segments serve to provide the electric "power :tor returning the basket 21, after having been emptied into the quenching tank I3, back to the loading station '43 for another load of work pieces. To start the return movement, the switch 8:1 is closed and held closed until the

trolley wheels

53 and 54 pass from the segments de to the segments e-a, whereupon the latter automatically takeover control to effect con- 'tinued movement of the trolley .35 until the wheels run onto the -de-energized segments -a-b. The rheostat I23 in this instance is adjusted to effect a rapid return movement of the .trolley -35.

The circuits to the motor 3! are momentarily interrupted each time the

trolley wheels

53 and 54 cross one of the insulated points a to e, -but the momentum of the trolley 35 is suificient .to carry the wheels across into electrical contact with the immediately succeeding conductor segments.

Considering now the operation of the hoist 38, the trolley wires 49 :to 52 are interrupted at nine points, to n, along the operating side of the 2100p .or circuit to provide insulated segments jg, 'gh, 'hi, io',.7-lc, lc-Z, Z-m, -m.n, and 11-1 which are correlated inlocation to the segments (1-4) to ea, so as to control the opera- .tion of the hoist in timed relation to the travel of the trolley.

The first set of segments f-g in the hoist control circuits coincide in length and position with the segments a-b, and are normally ole- -energized, but adapted to be connected to the main lines 08 and 99 through manual control circuits for selectively efiecting .forward and reverse operation of the hoist motor 00. More particularly, the up circuit is from main line 88, switch element I00, line I03, interlock switch I-25, and line I26 to the pair of segments .f-g .in the

trolley wires

50 and 52, and from main .line 99 through switch element !00, line I06, normally 'open manual control switch 121., and line I28, to the pair-0f segments f-g in the trolley wires 40 and 5t. The down circuit is from mainline 98 throng-h switch element I00 and line I03 to the pair of segments .j-g in the

trolley wires

50 and 5|, and from main line 99 through switch element I00, line 106, normally open manual control switch I29, and line I30 to the pair of segments j-g in the trolley wires 49 and 52. A magnetic coil -I3I :is connected across the lines 103 and I30, and serves when energized to open the interlock switch I25. The control switches =I-2I and I29 are adapted to be closed by means of suitable hand actuators I32 and I33. .It will be noted that the up and down circuits are the same except that the polarity of the segments jg in the trolley wires -EI and 52 connected to the armature 92 of the motor 40 is reversed. When the trolley 35 is at the loading station 43, switch I29 is closed to effect operation of the hoist motor 40 in a direction to lower the basket 2'I into -convenientposition for loading. After the basket has been 'loaded, the

switch I27 .is closed to reverse the operation of the :motor 40wso as to raise the loaded basket into elevated position.

The switch I01I is now closed to advance the trolley -35 to the galvanizing kettle I, the basket 9 21 being carried-in a straight horizontalpath indicated by the dotted line op (see Fig. 2); Since it is unnecessary to operate the hoist 38 during this approach movement, the next set of segments g--h, are not connected to-the source of electric current, but are dead and disable the circuits for the hoist motor 40. Upon movement of the trolley 35 from the rheostat I30, and line I 31 to the segments in trolley wires 49 and 52. As a result, the motor 40 will operate to automatically lower the loaded basket into the inlet end of the galvanizing kettle II at the rate determined by the adjustment of the rheostat I35. The resultant movement of the basket 27 thus follows the inclined pq.-

Whi1e'any suitable means may be provided for stopping the motor as when the loaded basket 21 has been lowered to the desired level in the zinc bath 24 beneath the blanket of flux, the length of the segments h-i is so determined in rela tion to the speed of travel of the trolley.35 and the speed at which the basket is lowered, that the trolley wheels 55 to 58 will pass from the live Sega ments h-i to the segments i:' to interrupt the motor circuits and thereby .stop the basket at the desired level. The segments are not energized, and extend along the length -.of the bath 24. Consequently, in the continued mov ee ment of the trolley 35, the basket 21 will be moved at this fixed low level slowly through the bath 24 along the path q-r. r

When the basket 21 reaches the dischargeend of the bath 24, the trolley wheels 55 to 58 'will pass from the dead segments z' i successively along the live segments i-k, and kl to the dead segments Z--m, thereby automatically transferring the basket along the path 1'st from the bath 24 over the dam or stopper 23 to the bath 25,

The circuit for energizing the segments j-Ie has a polarity operating the motor 40 in the up direction, and is from main line 98, through switch element I 00, line 838, rheostat 35 and line I40 to the segments in the

trolley wires

50 and 52, and from line 99, through switch element I00, and line I4! to the segmentsin trolley-wires 49 and 5i. The circuit for the segments Icl reverses the polarity of the motor 40, and is from main line 99, through switch element I00, line 142, adjustable rheostat I43, and line I44to the segments. in the

trolley wires

50 and 5| and from main line 99, through switch element. I00 and line I45 to the segments in the trolley wires 49 and 52. The two sets of segments a'k. and Ic-.l are comparatively short, and the rheostats l39 and I43 are adjusted to eifect operation of the motor 40 at a comparatively high rate of speed so'as'to' obtain aquick transfer of the loaded basket 21 from the bath 24 to the bath 25.

i As the trolley wheels 55ito 58 pass from the segments l -l to the dead's'egments l-m, the cir'-. cuit for the motor 40.is interrupted to maintain the basket 21 at the desired level of immersion in the bath 25 as'it is moved by the trolley35 along the path tu to the discharge end of the galvanizing kettle II. '1'

At the discharge end of the galvanizing kettle, the trolley wheels 55 to 58 for thehoist motor 40 pass from the dead segments Z-m to the normally deenergized segments m-n, and the

trolley wheels

53 and 54 for the trolley motor 31 pass from the segments cci to the segments (1-2,- thus stopping the trolley 35 unless and until the manual switch H80: is closed, as previously described. At this point in the operation, the basket 21 is adapted to be lifted from the bath 25 by energizing the segments mn through manual control, the circuit being from main line 98, through switch element 505, line H6, interlock switch I45, and line Mil to the segments in

trolley wires

50 and 52, and from main line 99, through contact element I00, line I48, normally open manual switch E and line I to the segments in the trolley wires 49 and EI. When the switch M9 is closed, as by the hand operator I5I, the armature polarity is such that the motor 40 will operate in an up direction to elevate the basket along the path u---v.

, In the subsequent travel of the trolley 35 alongthe segments d-e, the hoist motor 20 can be operated at will in either forward or reverse dimotion to lower or elevate the basket 2'! as required in the subsequent steps of the coating operation. .The down circuit for the segments 7n--n is from line 08, through switch element I00, and line H}? to the segments in the trolley wires 50 and 5 i and from main line 99, through switch element J00, line I48, normally open switch I52 provided with a hand actuator I53, and line I54 to the segments in the trolley wires 49 and 52. A magnetic coil !55 is connected across the lines 6 and I54, and is adapted, when energized, to open the interlock switch I45. It will be understood that all of the switch elements K00 are incorporated in one master switch for controlling the entire electrical system.

- After the loaded basket 21 has been lifted from the galvanizing kettle II or while lifting same, the switch II8a is closed to move the hasket along the path v-w into centered position over the centrifuge I2. Then, the switch IE2 is closed for a suificient time to lower the basket into the spinner 29. After the centrifuging operation, the switch I49 is closed to lift the basket 21 from the centrifuge l2. The switch H80, now is again closed to move the basket 21 along the path w-x into centered position over the quenching tank I 3. Then, the switch 152 is closed to lower the basket 21 into the dumping frame i3a which is operated to dum the work pieces into the chute I311. The switch E49 is then closed to lift the empty basket from the quenching tank I3. Finally, the switch 8a is closed to cause the trolley 35 to move from the segments c5-e to the segments e-a which automatically take over control to effect rapid return of the trolley with the empty basket to the starting segments a--b. The segments n-f are not energized since the basket 21 is carried in elevated position on the return movement.

It will be evident that I have provided a new and advantageous metal coating apparatus for translating a loaded work basket and for elevat-.' ing and lowering the basket at predetermined points in" the translation by power means so as to eliminate the arduous manual labor which has heretofore been required and to reduce the num-' ber of -attendants required to carry out the coatingoperation;

Preferably the operation is subject to manual control at the points where the time required is indeterminate, for example, at the loading, centrifuging, and quenching stations, but is fully automatic in passing the loaded basket through the galvanizing kettle ii, the basket beingautomatically lowered and elevated to immerse the work pieces first in the bath 24 and then in the bath 25, and being traversed in each instance through the bath, and the rates of movement be ing subject to adjustment in accordance with the operating requirements. As a result, the hazard normally involved in the dipping operations is eliminated, and these operations are carried out efliciently and with uniformity in repeated cycles. Since the basket need not be handled manually at any time, it can be larger than has been considered practicable heretofore, so as to utilize the full galvanizing capacity of the kettle.

I claim as my invention:

1. A conveying apparatus comprising, in com bination, a rail adapted to be suspended from an overhead support, a trolley supported by said rail for movement therealong, a variable speed electric motor for effecting movement of said trolley along said rail, a hoist carried by said trolley for movement therewith to support a work piece, a reversible electric motor for elevating and lowering said work piece, a first pair of trolley wires for supplying electric current to said trolley motor, a second pair of trolley wires for supplying electric current to the field of said hoist motor, a third pair of trolley wires for supplying electric current to the armature of said hoist motor, each of said three pairs of tro1- ley wires secured to said rail and extending therealong, each pair of wires comprising a series of axially aligned electrical conducting segments insulated from each other, and forming corresponding pairs of conducting segments, a plurality of individual rolling contacts carried by said trolley and contacting said wires, separate electric operating circuits connecting the contacts contacting said first, second and third pairs of wires respectively to the trolley motor, and to the field and to the armature of said hoist motor, a plurality of individual electric energizing circuits for connecting said first pairs of conducting seg ments, for said trolley motor to a source of electric ciu'rent, and a plurality of additional electrical energizing circuits for connecting certain of said second and third pairs of conducting segments for said hoist motor with alternately reversed poles of a source of direct current to alternately reverse the direction of current supplied to said hoist motor to reverse the direction of rotation thereof, each energizing circuit for said pairs of conducting segments for said trolley motor including an adjustable rheostat for controlling the motor speed.

2. A conveying apparatus comprising a rail adapted to extend along and to be mounted over; av plurality of operating units arranged in func: tional position, a trolley supported on and, movable along said rail, a variable speed motor carried by said trolley for driving the trolley along said rail, an electrical circuit for energization of; the motor to drive said trolley progressively along,

said rail at a succession of pre-selected rates of; speed, said circuit including separate closely spaced aligned pairs of conductors extending along the length of said rails, means, connecting;

each of said pairs of conductors to a source Qtalso carried by said trolley, work elevating and lowering means on said hoist for carrying a work piece, and means for energizing the armature and field of said hoist motor to selectively operate said work elevating and lowering means in predetermined time relation to the movement of said trolley, said means including a pair of condoctors extending along the length of said rail, an operating circuit connecting said conductors to the field of said hoist motor, means connecting said conductors to a source of direct current, a second pair of conductors extending along the length of said rail and divided into a plurality of closely spaced separate insulated segments, an operating electric circuit for connecting said second pair of conductors to the armature of said hoist motor, and means individually connecting each of the segments of said second pair of conductors to a source of direct current with adjacent segments being alternately connected to the positive "and negative sides of said source of current to reverse the polarity of the armature of said hoist motor to thereby alternately elevate a d lower said workpiece as said trolley is advanced along said rail.

:3. A conveyor apparatus comprising a monorail extending through a closed loop and suspended from an overhead support over a series of units arranged in functional alignment, said along said rail, a hoist mounted on said trolley for movement therewith and having means for supporting a work piece, a reversible variable speed electric motor for elevating and lowering said work piece supporting means, a plurality or pairs of trolley wires extending in closed loops around said rail and each pair comprising a series of closely spaced aligned parallel electrical conducting pairs of corresponding segments insulated from each other, means for supporting said trolley wires from said rail, an indi-v vidual electrical contact for each wire supported bysaid rail, electric-operating circuits connecting the contacts for one paircf wires to. the trolley motor, electric operating circuits connecting the contacts for the other pairs of wires to the arma-. ture and field oi'said hoist motor, and a plurality of individual electric energizing circuits for conheating certain ofsaid conducting segments respectively to a source of electric current, each energizing circuit including an adjustable impedance for controlling the impressed voltage, certain of Said energizing circuits being closed to constantly energize the associated segments, the remainder of said energizing circuits being normally open and adapted to be closed at, the energizing circuits for successive pairs of segments connected to said armature being alternately reversed in polarity to alternately raise an lower said work. pportin means as the trolley is. advanced, along the rail.

4 conveyor adapted for advancing work h ugh a a ng apparatus, compris n a t ack. a, trolley carried, by said. track for movement therealqne. me us. foradvapcing said trolley along aid r s a ho st carried by sa trolley and. hav n work levating and lowering means. a reversible'variable speed motor tor driving said ho st e evate or low r sai ork ele atin and awerine means a. first. pair of conductors insu'latedly carried by said track and extending along the length thereof for electrically energizing the field of said hoist motor, a second pair of conductors for energizing the armature of said hoist motor, each of said conductors being divided into aligned closely spaced segments separated by insulating gaps, and forming corresponding pairs of conducting segments, and individual control circuits for said pairs of segments, said circuits including additional conductors connecting the segments of said pairs of conductors to a source of direct current to energize the field and armature of said hoist motor, the additional conductors connecting said second pair of conductors to said source being each alternately connected to the positive and negative poles of said source of current to successively reverse the polarity of the armature and the direction of rotation of the hoist motor, thereby alternately elevating and lowering the Work supporting means as the trolley is advanced along said track.

5. A conveyor adapted to control movement of work in horizontal and vertical planes which comprises an overhead looped horizontal track, a trolley suspended on said track, a hoist on said trolley, work supporting means carried by said hoist, a variable speed electric motor carried by said trolley for advancing the trolley along the track, a reversible electric motor for driving the hoist.to raise and lower said Work supporting means, two sets of conductors extending along said track, each of said conductors being composed of a plurality of aligned closely spaced segments, separate circuits for energizing the segments of said conductors, and contactors on the trolley connecting one set of conductors with the motor for driving the trolley and the other set of conductors with the motor for driving the hoist, said circuits including means for connecting the individual segments of said one set of conductors to a source of electrical energy, an adjustable impedance for controlling the impressed voltage in said one set of conductors and thereby the speed of travel of said trolley, means for alternately connecting the individual se ments of said other set of conductors to the positive and negative poles of a source of direct current to alternately reverse the polarity of current introduced into the reversible hoist motor, thereby elevating and lowering the work supporting means of the hoist while said trolley is advanced along said track.

FREDERICK C. BRIGHTLY, JR.

REFERENCES CITED lfhe following references are of record in the file of this patent:

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