US2646746A - Control system for billet marking - Google Patents

Description

July 28, 1953 Filed April 1, 1947 H. E. MULLER, SR

CONTROL SYSTEM FOR BILLET MARKING 3 Sheets-Sheet l 3nnentor Her/77 an E. mu/e- .5/1

Hxs Gttorneg July 28, 1953 H. MULLER, SR 2,646,746

CONTROL SYSTEM FOR BILLET MARKING Filed April 1, 1947 3 Sheets-Sheet 2 fig. 2.

3nnentor fie/777 m E. Mid/er 5/:

July 28, 1953 H. E. MULLER, SR

6 I CONTROL SYSTEM FOR BILLET MARKING Filed April 1, 1947 fig. 4.

3 She ecs-Sheet 3 Z'mnentor Herman E. Mu//e/' Jr. 8

H la altorneg Patented July 28, 1953 Herman E. Mullen-Sr Swissvaley-Pag' assignor 1 to United States Steel Corporation, .a. corpora-' tion of New Jersey Application April 1', 1947,Serial Manama .zoiaimsl (o1. 101-4).

I "This invention relates to control systems, and more particularly to control systems for apparams for performing a predetermined'operation on a'fwork object which is moved along a conveyor, although not limited thereto;

Accordin to anillustrative embodiment, the apparatus ofjthe present invention may be utilized in combination with a billet stampingapparatus, the same being illustrated in the drawings and described more fully hereinafter.

,In some steelmills. it is the practice to stamp the end of heavy metal billets with the number of the; heat of steel from which they were made. Ordinarily the stamping of the end of the billet isjaccomplished as it' rnoves along a conveyor. In the past this has been accomplished by an operationilwhich is either manual, or manually initiated; In some cases it has been found expedient to; move the billets endwise along a conveyor and tomount over the conveyor a pivoted arm on which the heat numbers are detachably mounted, thejsa'i'd iarm'being actuated by an adjacently disposedfluid cylinder through the medium of a control switch, itself susceptible to manual operation. "Morerecently the manually operated switch has been superseded by photoelectric controls. It hasheretofore been proposed to so mount photoelectric or light-sensitive cells, and their Iightsourceathat the advancing end of the billet will interrupt the light, to the first cell, but the solenoid will notbe actuated until the advancing end of the, billet interrupts the light to the second celL-at which time the trailing end of the billet islimmediately below the operative point, of the swinging arm carrying the billet stamp ;f and it is at, thisjpoint thatthe fluid cylinder is actuated t'oswing the arm in its lowermost position and thereby move. the said billet stamp against the trailing end of the ingot with the, requisite force.

, While no difiiculty or danger is to be experienced were the light rays to the first of these photoelectric cells accidentally interrupted, it has been found that the accidental interruption of light rays to the second photoelectric cell while any portion of the advancing billet is interrupting the light rays ,to the first cell will result in the accidental and possibly dangerous downward movement of the heavy swinging arm with its heavy billet stamp. It is accordingly among the objects of the present invention to provide a control system which may be used in various operations such as the motivation of the billet stampin apparatus referred to, and by means of which the desired control of the apparatus is insured against improvident or accidental operation.

through a downward arc 2 Another object is the-attainment of thefore going by the use of instrumentalities which are simple and inexpensive to manufacture and install, and ones which are at the same time quite durable in service. h a.

The invention, then, comprises the features hereinafter described and'as particularly pointed out in the claims, the following description-and the annexed drawings setting forth in detail certain illustrative embodiments ofthe invention,

these being indicative of several of the number of ways in which the principles of the invention may be employed.

In said drawingsz. Figure 1 is a side elevation of a conventional inclined conveyor of the'type adapted to'endwise or longitudinally move a succession of heavy steel billets, the said conveyor being provided with a superposed billet stamping apparatus;

Figure 2 is a plan of the showing of Figure 1 but on a reduced scale, and showing in addition certain photoelectric cells and light sources which will be described more fully hereinafter;

Figure 3 is a simple and conventionalelectric circuit which may be utilized to operate the instrumentalities of the control system of the present invention; 7 v

Figure 4 is a fragmentary enlarged elevation of a modified solenoid system; and

Figure 5 is a simplified electric circuit which may be utilized to operate the instrumentalities embodying the modified solenoid system of Figure 4.

.Referring more particularly to the drawings. the. numeral 2 generally designates an inclined conveyor comprising a plurality of suitably driven conveyor rolls which are, constructed and arranged to successively feed elongate metal billets, or other workpieces, in ,endwise fashion.

' Asshown most clearly in Figures 1 and 2, a frame 3 is mounted. atop the inclined conveyor and carries-an elevated and transverselyexte'n'd ing rotatable shaft 4.. Secured to this rotatable shaft 4 is oneend of an arm 5, the other of, which carries a heavy'marking head 6; Suitable nume bers, or other marking media 1, aredetachably carried -by the head 6, the samebeing soconstructed andarranged as to permit of, marking one end of a metallic billet when the pivotally mounted .arm 5 is moved with-sufficient force The frame};carriegadoubh-acting air cylinder I0, the outerand*inner ends of which com municatewith-aim-conduits n and I2, respectively. yflhese airconduits ll and- :l2 connect througha valve l3.with an air supply pipe I4. An

operating lever I5 is operable to alternately connect the air conduits l l and I2 with the air supply pipe l4 and an air exhaust pipe H.

The piston of the double-acting air cylinder is provided with the usual piston rod 20, and to the latter there is pivotally connected an elongate rod 2| which extends over the arm 5. The extended end of the elongate rod 2| is pivotally C0111 nected to one end of a link 22, the other end of the said link being secured to the rotatable shaft 4.

Referring to Figures 2 and 3 of the drawings, as the elongate metal billets are. movedalong the inclined conveyor 2 and pass under the frame 3:, they travel through a field across which there is focussed a series of three substantially spaced photoelectric or other light-sensitive units, as shown at 50, 5| and 52. The distance between the. first and third of these light-sensitive units is approximately the same as the length of the metal billets (or other workpieces) which are to be marked by the marking media I carried by the marking head ii on the outer end of the pivotally mounted arm 5, the reason for which will appear short y here af r- Each of the light-sensitive units 50, 5! and 52 is, actuated by a light source, as at 53, 54 and 55, respective which s p io immediately o PDSite, on the other side of the conveyor and at r such points as will enable the light rays emanating thereirorn to be intercepted by the metal billets during their forward movement along the inclined conveyor 2.

their own circuitthe light-sensitive units 50, 5t and re connected in parallel, whereas the ccntacto s of the relays they operate are connected in serie and operate -a solenoid unit 65, which comprises a spring-loaded single-acting cylinder. Referring back to Figure 1, this solenoid unit 65 actuatesthe operating lever l5 of the control valve I3. That is,'when the solenoid 65 is energizedit will swing the lever 15 of the control valve lei in the direction opposite to that shown in Figure 1, with the result that the piston (not shown); within the air cylinder It is caused to move to the right, causing the piston rod 20 and its pivotally connected elongate rod 2i to move in the same direction, with the end result that the pivotally mounted arm 5 and its marking head iii are. caused to swing downwardly. In this manner, then, the numbers or other marking media T are caused to make contact with the trailing end of a metal billet which is advancing along theinclined conveyor 2 and through a suitable guide, such as the conventional bell illustrated in Figure 1. When the solenoid unit 65 is deenergized the spring within its single-acting cylinder causes the lever IE or the control valve to eturn 9.. t n tia po iti n. as iuF s r fhus th wqrk h cycle f. he contr l ve. 315 suppl a, matt r of lte nat ly s-ener izin or ener izin h qidfln wh this eri nsd hr h en i o os he c n a t r .13. h nlay the i ht-sensi iv n t .0..

' S s h m nner. Opening or cl s n he 91 tacts of the relays of the hereinbefore described light-sensitive units 59;, 5l and 52; thesaid units are, like their respectivelight-sources 53;;5ilfand 55-, connected in parallel, whereasthe contactors of the photoelectric relays which thesaidcontrol- (and which in turn control the solenoid unit 65) are in series. 'W-ith the main switch Gill n closed position and the operating armo f;- the switch 62 in its downward or automatic posrtion, the current flows to all ofthe photoelectric units directly, except to the solenoid unit 65, for the reason that the contactors of the relays of the light-sensitive units 5| and 52 are normally open, while the contactors of the relay of the light-sensitive unit are normally closed, all as hown in Figure 3.

If any interruption or the light rays emanating from the light sources 53., 54 and 55 causes a reaction on the contactors of the relays of the lightsensitive units, it will have no effect on the soler gid unit 65. if one or the contactors is still open" because they are all connected in series.

As the. metal billet moves along the inclined conveyor 2, its. leading end interrupts the light rays emanating from the light source 53, thereby opening the. conta-ctors of the relay of the lightsensitive unit 50. In progressing forwardly the billet, then interrupts the light rays emanating from the light source 54', with the result that the contact-ors of the relay of the light-sensitive unit 5! are closed. In progressing further along the inclined conveyor 2' the leading end of the billet intercepts the light ray emanati g iromthe, light source 55, thereby closing the contactors of the relay of the light-sensitive or photoelectric unit 52. Up until now the operating circuits oi the photoelectric unit 5| and the photoelectric. uni 52 are closed, but the operating circuit for the photoelectric unit 55 is open. Accordingly there is no. energization oi the solenoid unit. 55, and this is for the reason that the billet is not as yet in position to be marked. However, in a very short interval of time the trailing endof the billet passes from between the light source 53. and the photoelectric unit 59 with the result that the circuit of the latter (which was up. until now open.) is closed. The solenoid 6.5. i energized. Withthe result that the, arm 5. is swung downwardly in the manner hereinbefore described, thus causing the trailing end of the billet to be marked by the numbers or other indicating media 1, carried in the marking head 6. The movement of the lever I5 of the control valve l3 in the opposite direction to that illustrated in Figure 1 causes the said valve to permit compressed air to enter the air cylinder lflthrough the air conduit I2. The pive otally mounted arm 5 remains in a down position until the trailing end of the billetpassesthe light rays emanating from the light sources5, 4f and, 55, at which time there is broken the circuitsoi the photoelectric units 5l and 52, thus deenergizing the. solenoid 6 5 and permitting the spring within the spring-loaded single-acting air cylinder I ll to operatethe valve [3 to reverse the flow of air and permit same to flow through the. air conduit LI, thusreturning the arm 5 to its inoperative position.

According to the teachings of the present invention the. photoelectric unit 52 and its light source 55 constitute a safety measure as it prohibits the operation of the pivotally mountedarm 5 unless the circuits of both the photoelectric units 5,1 and 52 are simultaneously broken, as is the case when a billet passes. The purpose of this is to prevent accidental operation Qf. the pivotally mounted arm 5 due to a dropped tool or passing hand of the operator which might break the light beam.

Referring to Figures 4 and 5 of the drawings, there is illustrated a modified form of the invention which contemplates the use of two opposed solenoids 66 and 6'! in lieu of the single solenoid of- Figures l through 3. According to this permissive embodiment one of the solenoids (i. e.

.5 erative position. This modification may be practiced by simply disposing the solenoids '66 and 61 in the opposed positions shown in Figure 4 with their thrustor shafts in alignment and connected together through a link M which is provided with a pivotal connection 69 for receiving the outer end of the operating lever I5 of the control valve [3.

If desired, suitable manual controls may be added and operated after moving the arm of the selector switch 62 into a vertical position with respect to the showings of Figures 3 and 5.

While I have shown and described certain specific embodiments of the present invention, it will be readily understood by those skilled in the art that I do not wish to be limited exactly thereto, since various modifications may be made without departing from the scope of the invention as defined in the appended claims.

I claim:

1. In combination with a conveyor and apparatus for marking the rearward ends of a series of billets being successively fed along the conveyor, said apparatus having a marking device in an initial operating position out of the path of travel of the billets, means for actuating the marking device to mark a billet and means for resetting the marking devic to initial position; a series of three light sensitive elements positioned along the conveyor, a light source positioned opposite each of said elements and directed across the conveyor toward its associated element at a height adapted to energize the same when a billet is not interposed therebetween, said elements being spaced along the path of travel of billets on the conveyor, the spacing between the first and last of the elements being equal approximately to the length of a billet, whereby each of said elements are deenergized in sequence by the lead end of a billet passing along the conveyor and are reenergized in the same sequence by the passing of the trailing end of the billet, a solenoid mechanically connected to the means for actuating the marking device and controlling the operation thereof, a first relay operable by the first of said series of light sensitive elements along the path of travel of the billets and having a pair of normally closed contacts opened by deenergization of said first element, a second relay operable by the second of said light sensitive elements and having a pair of normally open contacts closed by deenergization of said second element and a third relay operable by the third of said light sensitive elements and having a set of normally open contacts closed by deenergization of said third element, said solenoid and aforementioned contacts of said first, second and third relays being connected in series circuit to a suitable power source whereby the circuit to said solenoid is completed and the marking device is actuated only when the second and third light sensitive elements are in the deenergized state and the first light sensitive element is energized.

2. The combination of claim 1 which includes a solenoid mechanicallyconnected to the means for resetting the marking device to initial position and controlling the operation thereof, a first relay operable by the first of said series of light sensitive elements along the path of travel of the billets and having a pair of normally closed contacts opened by deenergization of said first element, a second relay operable by the second of said light sensitive elements and having a pair of normally closed contacts opened by deenergization of said second element and a third relay operable by the third of said light sensitive elements and having a pair of normally open contacts closed by deenergization of said third element, said solenoid and aforementioned contacts of said first, second and third relays being connected in series circuit to a suitable power source whereby the circuit to the solenoid is completed and the resetting means of the apparatus operated only when the third light sensitive element is deenergized and the first and second light sensitive elements are energized.

HERMAN E. MULLER, SR.

References Cited in the file of 'this patent UNITED STATES PATENTS Number Name Date 1,995,881 Cockrell et al Mar. 26, 1935 2,099,230 Rix Nov. 16, 1937 2,171,362 Gulliksen Aug. 29, 1939 2,339,204 Stockbarger et a1. Jan. 11, 1944 2,348,566 Papzian May 9, 1944 2,400,489 Dana et al May 21, 1946

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