US2605882A - Dipping conveyer - Google Patents

Description

Aug 5, 1952 T. H. CUR-ns 2,505,882

'DIPPING coNvEYER Filed April 18, 1950 v 'I 5 Sheets-Sheet 1 I Aug 5, 1952 T. H. CURTIS 2,605,882

DIPPING coNvEYER Filed April 18, 1950 5 Sheets-Sheet 2 Aug' 5, 1952 T. H. CURTIS 2,605,882

DIPPI'NG CONVEYER 5 Sheets-Sheet 3 Filed April 18, 1950 /N VEN TOE THOMAS H. GUET/S l @www A TTOPNEYS.

Allg 5, 1952 T. H. CURTIS 2,605,832

' DIPPING CONVEYER 5 Sheets-Sheet 4 'Filed April 18, 1950 T. H. CURTIS DIPPING CONVEYER Aug. 5, 1952 5 Sheets-Sheet 5 Filed April 18, 1950 mln/N702 moms darf/s www fw Armi/wey;

Patented Aug. 5, 1952 UNITED STATES PATENTr OFFICE D-IPPING CONVEYER ThomasH. Curtis, Red Bank, N. J., assigner to Hanson-Van Winkle-Munning Company, Matawan, J., a corporation of New Jersey i Application April 18, 1950, Serial No. 156,626.

'1e claims. (c1. 19a- 19) 92 838, filed May 12, 1949, 154,077, filed April 5,

1950, and 156,627, filed April 18, 1950,1 have illustrated arrangements in connection with processing machines for selectively modifying the cycle thereof. The instant application is a further extension of the general thought embodied in these previous applications. I

The problem being treated is, generally, as follows:

Automatic machines are provided for processing workpieces through chemical, mechanical, and electrolytic treatments. The particular work cycle. with which the present invention is illustrated is a processing machine for conveying workpieces through chemical and electrolytic treatments. An example of such a treatment is the plating of various. sorts of workpieces such as typewriter parts, automobile hardware, building hardware, valves, and many other. types of y work members. So long as there is sutcient volume of any one type of workpiece to. maintain a processing machine in continuous operation, there is no need for the machine to have a eXible cycle. However, machines of this nature are capable of vast production and many times their utility could be materially enhanced if the operating cycle could be made suiiciently `flexible to accommodate at one time workpieces requiring diierent types of treatment.

An example of workpieces requiring different types of treatment is to be found in connection with automobile hardware referred to above. v This hardware consists of both inside and outside parts and it is desired that those on the outside carry a heavier plating deposit than those which are to be used on the inside because of the more severe weather conditions to whichthey are exposed.

In other cases, there may be two groups of parts to be processed, certain of which require one type of cleaning operations, and another of which requires another type ofv cleaning operations, `as where the one group would 'require a bright dip in an acid tank and the other group would not require the bright dip.

The particular object oi the present invention is to provide a. processing machine modified in such a manner that it can handle a variety of diierent types of workplaces `at the same time 2 and give each thereof the. proper overall treatment.r Y

Another object of this invention is to provide devices adapted for being-,associated with a processing .machine of a. more or less conventional type and which devices provide for a flexible cycle of operation of the machine whereby different types of workpieces can be operated on by the machine at the Sametime and receive selectively different types of treatment.

A still further object of this invention is the provision, in a processing machine having a plurality of workpiece carrying members, of devices associated with'the machine and control means for the devices such that the said members will receive selectively diiierentr treatment during one complete cycle of operation of the machine.

It is also an object of this invention to. provide a processing machine having a plurality of workpiece supporting members with devices controlled by the said members `for determining the particular treatment the workpieces supported by the members receive during one complete cycle of operation of the machine,

These and other objects and advantages will become more apparent upon reference to the following description taken in connection with the accompanying drawings in which:

Figure l is a diagrammatic elevational view showing a portion of a processing machine having devices associated therewith in accordance with this invention.

Figure 2 is a sectional view indicated by line 2-2 on Figure 1 and showing one form which the device of this invention can take.

Figure 3 is a View similar to Figure 2 but showing a slightly different mechanical arrangement of the device,

Figure 4 is a view similar to Figures 2 and 3 but showing a still different arrangement of the device.

Figure 5 is a view indicated by line 5,-.-5 on Figure 4 and showing the appearance oi the device of Figure 4 from the front and also showing a bridge arrangement that forms a part of a construction of Figure 1.

Figure 6 is a View indicated by line 6-5 on Figure 4 showing a limit switch for controlling the device and a cam for controlling the limit switch actuating member.

Figure 7 is a view showing still another form of a device according to this invention.

Figure 8 isa view looking in at the device of Figure '7 from the front.

Figure 9 is a diagrammatic view showing the 3 electric control circuit for the device of Figures 7 and 8.

Figures 10 and 11 show a modified arrangement which operates in a manner similar to the device of Figures 7 and 8.

Figure 12 is a view showing a thrustor arranged for actuating the device of Figures 7 and 8 'and a control circuit therefor.

Figure 13 is a view showing a modified construction of a device which is somewhat similar to that illustrated in Figure 2 and Figure 3.

Figure 14 is a diagrammatic view showing how a photocell circuit could be utilized for controlling the several devices in place of the limit switch arrangements illustrated; and

Figure 15 is a perspective view showing still another modified arrangement for selectively holding the carrier arms in an elevated position.

General arrangement In general, a processing machine of the type with which this invention is concerned comprises a frame I which provides'upper and lower channels i2 and i4, respectively, in which conveyor chains i and i8 run. Connected to these conveyor chains and extending therebetween at spaced intervals therealong are the spaced vertical channels 20 that provide guides for the skate-like slide members'22; These slide members include the projecting arm parts 24 that serve as supports for the workpieces to be treated.

Vertically reciprocable in the frame is an elevator structure 28 that includes a lift angle 28 projecting to beneaththe pick-up roller 30 on the back of slide member 22. Y

The conveyor chains and elevator are powerdriven and are interlocked in `such a manner that substantially all movement of the elevator takes place in the absence of movement of the conveyor chains and substantially all movement of the conveyor chains takes place while the elevator is in its uppermost position. In this manner the workpiece supporting arms are successively moved into a plurality of different Work stations and may be lowered therein for treatment of the workpieces as required.

The means for treating the workpieces generally comprises a series of tanks as at 32 in Figure 1. These tanks may be of a size to embrace only a single work station, as those at 34, or may extend for two or more work stations, as at 3S. When the tanks are only one work station in extent the workpieces are merely lowered therein and then raised from the tanks on the neXt upward movement of the elevator.

When the tanks extend over more than one work station, the workpieces are lowered into the tank at one end and then-remain lowered through successive movements of the conveyor until they reach the other end of the tank Where they are again engaged by the elevator and lifted upwardly.

According to this invention means are provided for selectively preventing the arms from being lowered at any one or more of the work stations whereby a complete tank or tanks or a portion of a tank or tanks can be bypassed thereby to vary the treatment of the workpieces on the arms. This is accomplished, according to this invention, by selectively interposing beneath some part of the work supporting arm or associated slide member an auXiliary element which will support this slide and arm when the elevator moves downwardly. These devices are controlled by adjustable means carried'on the arms so that each arm can be adjusted in accordance with the workpieces thereon to go through a new predetermined operative cycle.

M Odifcation of Figure 2 In Figure 2 there is illustrated a device in accordance with this invention and which occupies the positions in Figure 1 identified by the reference numeral 38. The device consists of an auxiliary bracket 40 on frame l0 having slidably mounted thereon a plate 42 connected with a rod 44 normally urged by spring 46 to hold plate 42 in its4 dotted line position identified by numeral 48.

A solenoid S-i is connected with rod 44 by lever 5U so energization of S-l will move plate 42 into its full line position. Carried on the front side of slide 22 is an auxiliary roller 52 adapted for engagement on its underneath side by plate 42 when S-I is energized.

Energization of S-I is accomplished by closing of limit switch LS-i by cam 54 adjustably mounted on arm 24. The adjustable mounting of cam 54 permits it to be moved into position to engage switch LS-l to move plate 42 into operative position thereby to hold the arm in its upper position, or the cam may be adjusted to miss the limit switch whereby the arm will move downwardly according to a normal cycle.

By placing the devices of Figure 2 at the positions 38 any one or more of the first four tanks or the first position of the last tank can be bypassed.

When the rst position of the rst tank, that is the position at the extreme right end of the first tank, is not bypassed, the arm remains lowered during one movement of the conveyor chains and is then elevated at the position marked 55. At position 56 there is a bridge on the machine frame which is shown in Figure 5 at 58 and which comprises a bridge plate 60 positioned to extend across an opening 62 in the elevator lift angle 28 when the elevator is up. Bridge plate 60 is normally urged down by springs 64 but will yield upwardly to its dotted line position 66 to admit the roller 30 of a workarm aligned therewith so that workpiece supporting arms which were lowered at the first Workstation of the tank will not be interferred with by the plate 60, whereas the arms which were held in an elevated position at the rst work station of the said tank will roll over bridge plate 60 as though thelift angle 28 were continuous.

For lifting the work arms that were lowered in the first position of the rst tank, when they are aligned with the said bridge, there is an auxiliary lift element or ipper 68 on the elevator tting in the space or opening 62 of the elevator lift angle 28 which is normally. positioned to engage roller `30 but which will cam over the said roller when the elevator moves downward. A iiipper of this nature is illustrated at 68 in Figure 2.

For lowering the work supporting arms at the first station of the tank at the right end of Figure 1 when the hold out plate 42 is in its upper position, a somewhat different type of flipper than that referred to above is mounted on the elevator. A ipper of this type is illustrated at 1U in Figure 4 and comprises plate 12 normally held by springs 'I4 in position to receive roller 30 when the conveyor operates, but adaptedfor being moved out of alignment with the said roller by yielding plunger 'I6 mounted on frame l0 adjacent the lowered position of the arm.

In this manner the elevator will receive the arm in its upper position and then release it at its lower position.

In the foregoing it will be seen that by adjusting cam 54 on the associated carrier arm, the said arm may be conveyed through any of a number of different types of Work ycycles in one and the same machine.

Modification of Figure 3 In Figure 3 substantially the same structure is employed as was illustrated and described in connection with Figure 2 and the same reference numerals are appended to corresponding parts. In Figure 3, however, the hold out plate 78 is pivoted at B on auxiliary frame lo and is normally urged by spring 82 into ineffective position. Energization of solenoid SL-2 will move plate 'i8 about its pivot into effective position. The arrangement of Figure 3 is somewhat more compactand simpler to construct than the arrangement of Figure 2 but operates in a corresponding manner.

M odz'jcatzon of Figure 4 In Figure 4 there is shown an arrangement which is also quite similar to that of Figure 2 and to which the same reference numerals have been appended where applicable. In Figure 4 the principal difference is that the hold out plate Si is adapted for engagement with roller 3G and thus the auxiliary roller 52 of Figures 2 and 3 is not necessary.

I-Iold out plate 84 is mounted on blocls @Ei connected with rod 88 normally urged by spring Sii to hold the plate in its ineffective position. yEnergization of S-3 similarly to energization of S-E will move the plate to its effective position.

The cam 54 shown in Figures 2, 3 and i is somewhat better illustrated in Figure 6 wherein it will be seen to comprise a rather elongated element which will engage limit switch LS-l in advance of the movement of the associated workpiece supporting arm into the work station so that hold out plate, whether it be the type of Figures 2, 3 or 4, will have time to move into effective position before the arm is aligned therewith.

Modification of Figures 7, 8, and 9 In these figures there is shown a hold out arrangement wherein a rotatable column 96 is positioned adjacent the work station where it is desired selectively to prevent the workpiece carrying arms from moving downwardly. This column may be journaled in the spaced supporting bearing portions 92 and has on its upper end offset head portion 94 which in one position underlies the adjacent carrier arm and in another position is disposed to one side of the said arm,

One arrangement for rotating the column between its two positions comprises a worm wheel 9G on the column which is driven by a worm gear on the shaft of a reversible motor 9E. The limits of movement of the column may be determined by the limit switches ILS-2 and LS-S which are adapted for being engaged by finger it@ on the column at the two operative positions of the column. 1

Similarly, as with the modifications previously described, there is a limit switch adapted for selective actuation by the workpiece supporting arms. rI'his limit switch is indicated at ll-S-i and is characterized in that it has a pair of normally closed contacts and a pair of normally open contacts. A cam IGZ carried on the workpiece supporting arm is adapted for selective engagement with the limit switch in the manner already described in connection with Figure 6.

The control circuit for motor 98 and including limit switches LS-Z, L15-3 and LS-il is shown in Figure 9. In this view it will be seen that when limit switch LS-4 is in its actuated position the blade thereof which is in series with limit switch LS-Z is closed. This energizes motor 98 to run in a direction to turn column Soto position its offset head as shown in Figure 8 so as to support the workpiece carrying arm. Movement of the column continues until switch 'LS-2 is opened thereby de-energizing and halting the motor.

Thereafter, when the conveyor again moves so that cam |02 runs off limit switch LS-ll, the'blade thereof in series with limit switch LS-Swill be closed and motor 98 will be energized to'run in the opposite direction. This movement ofthe motor will continue until finger IBB engages and opens switch LS-3 thereby again lcle-energizing and halting the motor.

It will be seen that the described arrangement provides means for selectively supporting the arms in their elevated positions at any selected ones of the work stations of the machine.

In Figure 12 there is shown a somewhat modified manner of actuating column between its two positions. In Figure 12 there is a thrustor |64 which may be electric, hydraulic, pneumatic, or a combination thereof as desired, which is connected with column 9i) as illustrated. For controlling thrustor |04, -a cam |06 on armv 24 is adapted for engagement with 'a limit switch LES-5 thereby to energize coil |08 of a contactor havinga rst blade H0 which establishes a holding circuit for the coil through normally closed limit switch LS-B, and alsohaving a blade H2 in series with thrustor |94. If cam |116 is adjusted to engage and close switch LS- as the arm moves into the associated work station, then the contactor remains energized until'after the conveyor again operates to carry arm '24 into position for its cam' |06 to engage and open limit switch Ils-E. It will be evident that the arrangement illustrated in Figure 12 is-quite-similar to that described in connection with Figures '7 through 9.

Modification of Figures'l and 11 In Figures 10 `and 11 there is shown a construction which operates similar to that of Figures 7 and 8 but wherein the bulky and expensive column construction is eliminated. In Figures l()y and l1 an auxiliary bracket H4 is .mounted on the machine frame and pivoted thereon is a hook H5 adapted for hooking around the workpiece supporting arm as shown in Figure 10, or for being sprung out of the path of the said arm by spring l|8 as shown in Figure l1. A solenoid S-4 is energizable through the medium of limit switch LS-l and cam |20 in themanner previously described in connection with the other modifications.

Due to the fact that the work carrying arm settles downwardly somewhat when the elevator moves down following a conveying movement, it is preferable that the cam |20 present a substantially vertical switch actuating surface whereby the said settling downwardly of the arm will not bring about de-energization of solenoid S-, At the same time sufficient freedom of movement of the arm of the limitswitch may be had to permit the cam to pass therebeneath when conveyor movement is again resumed.

Modification of Figure 13 In Figure 13 there is shown a'modication which is quite similar to those of Figures 2, 3 and 4 in that an auxiliary hold out member |22 is arranged for being selectively moved to beneath a roller connected with the workpiece supporting arm and its supporting slide. In Figure 13, however, member |22 is pivoted at |24 and has an actuating lever |26 urged in a direction to move member |22 to its ineiiective position by spring |28, and adapted for being moved in a direction to place member |22 in effective position by energization of a solenoid S-5. As in connection with the other modifications there is provided a limit switch LS- and an actuating cam therefor |30 adjustably mounted on the workpiece supporting arm.

In connection with the modifications of Figures 2, 3 and 13 wherein the auxiliary roller 52 is employed, the vhold out members may be aligned with a hold out track, if desired, so that the workpiece supporting arms engaged by the said hold out members could be maintained in an elevated position for one or more further cycles of operation of the conveyor by the hold out track, if so desired.

Modification of Figure 14 In Figure 14 there is illustrated a simple photocell control circuit which could be utilized in place of any of the limit switches previously described. In Figure 14 there is a light source |50 that normally illuminates photocell |52. The photocell is in circuit with a battery |54 and a resistor |56 and when illuminated permits the battery to cause current to flow through the resistor in the direction of arrow |58.

Resistor |56 is in the grid to cathode circuit of a relay tube |60 which circuit includes also the biasing battery |62-, When current is owing through resistor |56 it holds the grid negative relative to the Acathode and prevents discharge of tube |60. However, when resistor |56 is not conducting current, battery |62 will bias the grid relative to the cathode so tube |60 does discharge and energizes relay coil |64 in the plate circuit of the tube.

Energization of the relay will cause its contacts |66 to close or open as desired and it will be evident that these contacts can be placed in any of the several arrangements described in place of any of the mechanically operated limit switches shown.

The photocell |52 is selectively made conductive or non-conductive by the flags |68 adjustably mounted on the workpiece supporting arms or their associated slides so that the same degree of selectivity of operation of the relay'obtains that obtains in connection with the mechanically operated limit switches.

Modification of Figure In Figure 15 there is shown still another modification wherein there is a block 200 freely vertically slidable on the guide rods 202 which are suitably xedly supported in the frame of the machine. Block 200 carries an angle clip 204 that is receivable in a gap in the lift angle of the elevator. A bar 206 connected with angle clip 204- extends over the elevator lift angle whereby when the elevator comes up the angle clip and its supporting block will also be elevated.

Secured to block 200 is a bracket 208 having a pivot pin 2 0 on which is pivotally mounted latch arm 2|2. The upper end of latch arm 2|2 is adapted for hooking over a xed element, such as the support plate 2| 4, when block 200 and angle clip 204 are raised to their highest position by the elevator. A spring 2|6 urges the latch arm toward the position in which it is i1- lustrated in Figure 15. v

The latch arm is adapted for being selectively disengaged by a cam 2 I8 adapted for engagement with roller 220 on the lower end of the latch arm. Cam 2|8 is adapted for being adjustably mounted on the screws 222 extending through slots 224 in the cam.

One of the cams 2I8 is provided for each of the carrier members it is desired selectively to set down in the various treatment positions that have associated therewith the slidable blocks 200 and angle clips 204. By adjusting the cams on the arms so they will engage the rollers 220, the associated work members will be set down in the normal manner. However, by adjusting the cam so that it will not strike the roller 220 or by removing the cam from the carrier member, the latch arm will remain effective for supporting the block and angle clip and in this manner prevent the associated work member from being set down.

It will be apparent that the latch arm could be normally engaged as shown, or could be normally disengaged with the cams being employed for selectively moving the latch arm into engagement. Similarly, while mechanical means are shown whereby the latch arm is directly actuated by the cam, it will be evident that pneumatic, hydraulic, electrical, or electronic means could be employed for detecting the setting of the cam and providing the actuating force for moving the latch arm to its proper position.

It will be understood that this invention is susceptible to modication in order to adapt it to different usages and conditions and, accordinglygit is desired to comprehend such modifications within this invention as may fall Within the scope of the appended claims.

I claim:

1. In a machine having a movable work member, a conveyor for moving said member in a horizontal direction, an elevator for moving said member in a vertical direction on said conveyor, stationarily supported hold-out means movable into engagement with said member for supporting it and thereby preventing its movement by said elevator, and means controlled by movements of said member by said conveyor for selectively moving said hold-out means between its effective and ineiective positions.

2. In a processing machine having a plurality of work stations, a work member, a conveyor on which the work member is vertically slidable intermittently operable for conveying said member to successive work stations, an elevator operable alternately with said conveyor for lifting said work member for a conveying movement and for setting said member down when the conveyor is halted, a hold-out member selectively adjustable for engagement with said work member to support the work member during downward movement of said elevator, and means controlled by said work member for selectively making said hold-out member effective or ineffective.

3. In a processing machine having a plurality of work stations, a work member, a conveyor on which said member is vertically slidable, intermittently operable for conveying said member to said work stations in succession, an elevator operable alternately with said conveyor for lifting *said member for a conveying movement and for setting the member down when the conveyor is halted, a hold-out member at one of said work stations normally positioned to permit the work `member to move down with said elevator, and

iframe, a Work member connected with the conveyor and vertically slidable thereon, an elevator operable for raisingand lowering said work member on said conveyor, said conveyor being ,intermittently operable to; convey said Ymember to said worlr Vstations in succession vand said elevator being oper-able alternately .with the conveyor `so thework member is. held up during a conveying movement and is then setdownin the work sta'- tions and lifted therefrom while the conveyor is halted, a hold-out member movably mounted on the frame at one of said work stations, actuating means for moving said hold-outmember between effective and ineiective positions, and means on the work member for controlling said actuating means.

5. In a processing machine having a frame, a plurality of work stations, .a work member, a conveyor on which the work member is vertically slidable for conveying thework member to said work stationsv in succession, and an elevator for raising the vwork member for conveying movement thereof and for lowering the work member when the conveyor is halted, a hold-out member on the frame at one of said work stations normally positioned to permit the work member to move down with the elevator at that station, actuating means for moving said hold-out member between effective and ineffective positions, and means on said work member adjustable into position to cause said actuating means to move said hold-out member into effective position in resp-onse to movement of said work member into the said work station.

6. In a processing machine having a frame, a

y plurality of work stations, a work member, a conveyor on which the Work member is vertically slidable for conveying the work member to said work stations in succession, and an elevator for raising the work member for conveying movement thereof and for lowering the work member when the conveyor is halted, a hold-out member on the frame at one of said work stations norm-ally positioned to permit the work member to move down with the elevator at that station, actuating means for moving said hold-out member between eiective and ineffective positions, means on said Work member adjustable into position to cause said actuating means to move said hold-out member into eiective position in response to movement of said Work member into the said Work station, and means responsive to movement of said work member out of said work station for causing said hold-out member to move to its ineffective position.

7. In a processing machine having a frame with a horizontally movable conveyor and a vertically movable elevator and a work member connected with the conveyor for movement therewith and vertically reciprocable thereon for movement with the elevator, said conveyor being intermittently operable for conveying the work member to a plurality of work stations and said elevator being operable alternately to said conveyor so as to lower and raise the work member while the conveyor is halted and to lhold the work member vated while the conveyor is moving, a part projecting from said work member, `a supporting member on Vtheir-ame at one of said stations adapted for engagement vwith said-projecting part when the member `is lifted, and actuating means responsive to movement of said memberV into said work station for moving said supporting member into effective position.

8. Ina processing machine having a `frame and a plurality of work stations, a plurality of work members comprising workpiece supporting devices, a conveyor in the lframe to move said members from-station to station, an elevator for vertically-reciprocating said members on the conveyor, said conveyor and'elevator operating alternately so conveying takesfplace only while the elevator is-upffa hold-out member yon said frame atat'least fone. work station'adapted in its effective position to engage the-work memberat that station `and to support it while the elevator goes down, said'hold-out'member also having'an ineffective position, means urging said hold-out member toward its ineffective position, actuating means energizable for moving said hold-out member into its `effective position, and means adjustably mounted on said work members for `selectively energizing said actuating means in responseto `vthe'movement of said members into saidone work station and for de-energizing said actuating lmeans in response to the movement of said Vworkmembers outo said one workstation.

9. In -a processing machine having a frame and a plurality of work stations, a plurality oi work members, a conveyor-to move said membersffrom station to station, an elevator engageable with the members from beneath for raising and lowering the members on the conveyor, said conveyor and elevator operating alternately so conveying only takes place while the elevator is up, a holdout plate movable on said frame at one of the work stations and adapted in one position to engage the work member in that station to support it while the elevator goes down, a spring urging the plate out of the said one position, and actuating means selectively responsive to movement of the said Workmembers into said one station for moving said hold-out plate into its effective position.

10. In a processing machine having a frame and a plurality of Work stations, a plurality of work members, a conveyor to move said members from station to station, an elevator engageable with the members from beneath for raising and lowering the members on the conveyor, said conveyor and elevator operating alternately so conveying only takes place while the elevator is up, a projecting portion on each of the work members, and a hold-out plate movably mounted on the frame having a iirst position where movement of the work members into the said one worl: station Will bring the projecting parts thereof into engagement with the hold-out member, said hold-out member having a second position out ci the path of said parts, electrical means energizable to move said hold-out member into its rst position, a switch for energizing said electrical means, and cams adjustably mounted on said work members for selective engagement with said switch as the said work members move into said one station.

1l. In a processing machine having a frame and a plurality of work stations, a plurality of work members, a conveyor to move said members from station to station, an elevator engageable with the members from beneath for raising and lowering the members on the conveyor, said conveyor and elevator operating alternately so conveying only takes place while the elevator is up, a hold-out member at one of said work stations comprising a hook-like element pivotally connected with said frame normally positioned to permit the work members to move with the elevator, electrical means energizable for moving said hook-like element into supporting engagement with a work member in elevated position in the said one station, a switch for controlling said electrical means, and cams adjustably mounted on said work arms for selectively actuating said switch as said work members are conveyed in elevated position into said one station.

12,. In a processing Ymachine having frame and a plurality of work stations, a plurality of work members, a convey'lrj'` move said members from station to station, an elevator engageable with the members from beneath for raising and lowering the members on the conveyor said conveyorand elevator operating alternately so conveying only takes place While the elevator is up, a holdout member at one of saidrstations comprising a vertical column having an offset head at `the upper end below the upper position of said work members and being rotatable into effective position to present the saidvhead to the underneath side of a work member in elevated position in the said station to support the work member when the elevator goes down, and means adjustably mounted on said work member selectively operable by the movement of said work members into said one station for controlling the rotation of said column into said effective position each such work member also being operable to cause return of said column to ineiectlve position upon movement of the arm out of said one station.

13. An arrangement as claimed in claim 5 in which the said actuating means for moving the hold-out member between eiective and ineffective positions comprises electrical means, a photoelectric control circuit for controlling said electrical means, and the said means on said work member adjustable into position to cause such actuating means to move said hold-out member into effective position in response to movement of said work member into the said work station comprising a mask adjustably carried by the said work member so as to be selectively positionable into position to cause a change in the illumination of the photocell of the said photocell control circuit as the work member moves into operative position relative to the said hold-out member. Y

THOMAS I-I. CURTIS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,937,359 Ritter Nov. 28, 1933 2,175,788 Todd Oct. 10, 1939 2,461,113 Friedman Feb. 8, 1949 FOREIGN PATENTS Number Country Date 375,505 -Great Britain June 30, 1932

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