US2684769A - Step-by-step feeding mechanism - Google Patents

Description

2 Sheets-Sheet l J. WALLERIUS ET AL STEP-BY-STEP FEEDING MECHANISM July 27, 1954 Filed Aug. 24, 1949 Patented July 27, 1954 ATE NT "OFFICE STEP-BY-STEP FEEDING MECHANISM Application August 24, 1949; Serial No; 112,062

1 Claim. l

This invention relates tofeed mechanisms for furnaces andv more particularly to feed mechanisms in which there `is both a horizontal and a vertical movement and the movements areso coordinated that `an article can-beadvanced through a furnace in a step by step manner.

vHeretofore feed mechanisms of the above cha-racter have not been satisfactory in all respects. For example one of the objections to prior feed mechanisms of this character is that they are rather complicated. Too, they have also employed cams foreffecting the Vrespective movements and because of the stresses involved the cams wear. `As a result uniform horizontal and vertical movements are not obtained and consequently the articles are not fed through the furnace properly. Another objection has been that the cams haveV to be replaced frequently. Due to the complex character of feeding mechanisms for prior designs of furnaces the feed r mechanisms are rather diicult to service and consequently the maintenancecosts are relatively high.

Accordingly, an object of this invention is to provide a novel feed mechanism of the above character with means for effecting a positive movement in bot-h horizontal and vertical directions.

Another objcct of the invention-is to provide a feed mechanism of the above character that is simple to construct, that permits accessibility to all moving parts, that is easy to service, and that isrelatively inexpensive to produce.

Other objects-and advantages ofthe invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which- Figure 1 is a longitudinal sectional view of-a furnace embodying the present-'invention with the vertically movable support means vin a raised position;

liig.2 is a fragmentary view similar to Figure l showing the vertically movable support means in a retracted position;

Fig. 3 is an endview of Figure 1; and

Fig. 4 is ari-enlarged sectional view taken substantially along'the lines-ll-'d'fof liigure l.

Referring now to the drawings, the Vinvention is shownk embodied in a feed mechanism for al furnace designated generally 4by the vnumeral l l. In generalthe furnace includes a bottom portion l2, sides i3 and Manda top (not-shown) formed of Vsuitablerefractory material, and defining a heatingrchamber |16^having openings ilY andfl, respectivelyyat the charge and discharge end of 2 the Vfurnace il. The furnace may be heated by any suitable means. For purposes of-simplifying the drawingsthe latter has been omitted. Vertically movable doors`2l and 22, respectively, close the openings il and i8. `-The feed mechanism in general comprises carrier means reciprocable between horizontal positions for moving workpieces i9 horizontally between preselected positions and vertically movable support means for supporting the workpieces-an'dmovable betweena retracted position in which the workpieces rest on the horizontally movable carrier for movement in unison therewithanda position in which Vthe Workpieces I9 are raised above the carrier to permit the Vcarrier to be moved horizontally independently of the workpieces I9. Suitable means may be utilized for coordinating the respective movements of the carrier and vthe support means so that the workpieces are advanced ina step by step mannerthrough'the heating chamber I6 of the furnacel I l.

As -best seen in Figs. land 4 the carrier means comprises a pair-of link chainsy 23. The latter are disposed in spaced-troughshaped guideways 26v disposed lengthwise on the bottoml l2l of the furnace l l. `Preferablythe guideways are formed -of material having goodwearresisting qualities,

one such material being Carborundum. At the charge end of the furnace the chains 23 are supported by spaced sprockets 2 mounted on a transversely extending shaft 28. The latter is supported -byfasuitable support 29 mounted on the framework 3| supporting the furnace I I. The shaft 28 is spaced from the charge'end of the furnace a sufficient distance so that the portions of the chains 23 between the sprockets 2l and the end of the furnace II form a table portion lat the chargeend ofthe furnace forrsupporting the workpieces. `After passing over the sprockets 27 the -chains23` are connected to a crossheadd.

The crosshead is connected to one end of a piston (not shown) of -a pressure fluid unit 34 by a rod 3S. The pressure fluid unit 34 is shown mounted on the vframework 3i beneath the bottom i2 of the furnace i i. At the opposite end of the furnace the chains 23 are mounted on spaced sprockets 3l (one only being shown) mounted on a transversely extending shaft 38, the latter being supported Vby a suitable support 39 mounted on the framework 3 i. The shaft 38 is spaced from the dischargeend of the furnace a su'iiicient distance so that the portions ofthe chains 23 between the sprockets 37 and the end ofthe furnace form Vatable portion for supporting the workpiecesafter they are 'discharged from the furnace. After passing over the sprockets 3l the ends of the chains 23 are interconnected by a crosshead 4l which in turn is connected to the opposite end of the piston in the pressure fluid unit 3d by a cable 42. A turnbuckle 43 is connected in series with the cable l2 for varying the slack in the chains 23 to permit of adjustment of the tension in the chains 23.

The ow of pressure fluid to the pressure fluid unit 34 is under the control of a suitable conventional control valve unit lift. The latter is connected with opposite ends of the pressure fluid unit SLi by conduits 4t and 4l, respectively, and is connected to a pressure fluid source by a conduit d8. Inasmuch as any conventional valve unit fifi may be utilized, for purposes of simplifying the drawings in this instance, the valve unit lili is shown herein by symbol only. With this construction the flow of pressure fluid may be directed to either end of the pressure huid unit 3d. Thus, by alternately applying the pressure fluid first to one end of the unit 313 and then to the other end the chains 23 may be caused to reciprocate between opposed positions, the distance of movement being equal to the stroke of the piston in the unit lill.

The vertically movable support means, in this instance, includes a plurality of vertically disposed uprights 5l extending through openings 52 in the bottom i2 of the furnace. The uprights 5! are disposed in alined rows adjacent the side walls i3 and i4, respectively, of the furnace. Spaced outwardly from opposite ends of the furnace are spaced uprights 53, respectively, in alinement with the rows of uprights 5i. Beams 5d extending between adjacent uprights in each row are suitably supported to have their upper surfaces disposed in a substantially common plane and to define spaced workpiece supports extending lengthwise of the furnace shaped to support opposite edges respectively of workpieces is being advanced through the furnace. To support the beams the uprights 53 are formed with caps 56 including a central portion 5l extending upwardly from spaced shoulders 5d and the uprights 5l are provided with caps 5S including a central portion 85 extending upwardly from spaced shoulders 6ta. The tops of the central portions 5i and the tops of the central portions 'i5 are disposed in a substantially common plane. As best seen in Figs. 3 and 4 the beams 513 have an inverted U-shaped cross section and are arranged so that the bridging portion of the beamsr rests on the tops of the central portions and the leg portions straddle the central portions. Each of the beams 5s is pivotally mounted at one end and has its opposite end freely supported. Adjacent beams 5d are in spaced endwise relation to allow for expansion of the beams when the furnace is brought up to ternperature. The uprights 5i are mounted for reciprocation in suitable vertically arranged guides Gl attached to and depending from the bottom l2 of the furnace and the uprights 53 are supported in suitable guides d2 supported on the framewor 3i at opposite ends of the furnace.

At the bottom of each upright is a toggle joint it. The toggle joints for the uprights 5i and 53 are of similar construction. For purposes of simplification therefore only one of the toggle joints 'iii will be described in detail. As best seen in Fig. 4 each toggle joint IG includes spaced bars fit each pivotally connected at one end to a pin 51. rlhe latter extends through the upright 5I and projects through vertically elongated slots B8 formed in the guide fil on opposite sides of the upright 5l. The opposite ends of the spaced bars 66 are respectively pivotally connected to one end of spaced bars t as by a pin li. The opposite ends of the spaced bars 65 are pivotally supported on a shaft l2. The latter is supported by suitable spaced supports 'I3 mounted on spaced channel irons '.14 forming a part of the framework 3i. The supports 'i3 are disposed in spaced axial relation to the lower ends of the respective uprights. A spacer i6 maintains the lower ends of the bars 69 in spaced relation. The pivotal connection between the spaced bars 66 and 69 forms a knee.

Driving links 'l'i extend lengthwise of the framework 3i below the furnace ll in alinement with each row of uprights. Each link 'i1 is pivotally connected to all of the knees in one of the rows of uprights. As best seen in Fig. 4 the driving links 'Vi are supported on pivot pins Il between the spaced bars GS. Spacers i8 position the link T intermediate the bars 69.

Suitable provision is made for moving the links 'Vi to simultaneously move all of the knees of the toggle joints 'iii between opposed positions on one side of an axis defined by alinement of the bars 55 and 59 to raise the uprights to a position in which the top surfaces of the beams 54 are above the workpiece supporting surfaces of the chains 23 and a retracted position in which the top surfaces of the beams 5d are below the supporting surfaces of the chains 23. As shown in Figs. 2 and 3, at the charge end of the furnace, each driving link "il is connected to a link li in turn pivotally connected to one end of an arm Si; the latter is keyed to a shaft 82 supported by suitable bearings, not shown, mounted on vertical members S3 forming part of the framework Si. Intermediate the arms Si is an arm 811 keyed to the shaft 82 and having its free end pivotally connected to one end of a piston (not shown) mounted in a pressure iiuid unit 8i. The pressure fluid unit in this embodiment of the invention is under the control of a control valve unit 88. The latter is connected to opposite ends of the pressure fluid unit by conduits 89 and 9 i, respectively, and to a source of pressure fluid by a conduit S2.

The control valve units lili and 28 may be provided with a suitable timing mechanism incorporated in each unit in a conventional manner to coordinate the movements of the carrier and the support means. The opening and closing of the doors 2l may also be controlled by the timing mechanisms in the control units so that the doors open and close in coordinated timed relation with the horizontal movement of the carrier and the vertical movement of the supports. Where desired a master timing device may be employed for controlling the movements of the carrier and supports means and the opening and closing of the doors.

The operation of the aforegoing feed mechanism is apparent from the above description but may be summarized briefly as follows: As shown in Figure 1 the vertically movable supports are in their raised position. With the parts in this position the operator places workpieces i9 on the beams 5t at the charge end of the furnace. The uprights 5| and 53 are then moved to a retracted position. This is effected by applying pressure uid to the pressure fluid unit 8l to cause the arm 84 to rotate in counterclockwise direction as viewed in Figs. l and 2. Simultaneously the arm 8| is rotated in a counterclockwise direction and the driving links il are shifted to the left of the position they assume in Figure i. At the conclusion of this shifting movement the links 'il are in the position shown in Fig. 2 and the uprights are in a retracted position so that workpieces rest on the chains 23. Simultaneously with the retraction of the support means pressure fluid is applied through the conduit 46 to the left hand end (as viewed in Figure l) of the pressure fluid unit 3Q to eifect movement of the chains 23 through the furnace. This advances the workpieces I9 in the direction of the furnace a distance corresponding to the length of the stroke of the piston in the pressure uid unit 34. At the conclusion of this movement of the chains the support means is raised to lift the workpieces I9 above the chains 23. This is effected by applying pressure uid to the unit 87 to cause the arm 8B to rotate in a clockwise direction as viewed in Fig. 2. Simultaneously the arm 8| is rotated in a clockwise direction and the driving links l? are shifted from their position shown in Fig. 2 to the position they assume shown in Figure 1. During this movement the knees of the toggle joints are moved to the right. Normally the bars 66 and 69 are disposed at an angle to each other. As the knees are moved to the right from the position they have in Fig. 2 they are urged toward a position of alinement. As they approach alinement the uprights 5I and 53 are forced upwardly. The closer the bars approach alinement the greater the force applied to the uprights. As soon as the workpieces I9 clear the chains 26 pressure fluid is applied to the pressure fluid unit 6d in a direction to effect reverse movement of the chains 23 a distance again corresponding to the length of the stroke of the piston of the unit 36. The. support means is then lowered as described above and so that the workpieces again rest on the chains 23. Pressure fluid is again directed to the pressure fluid unit 36 to effect forward movement of the chains 23 to advance the workpieces farther into the furnace. If it is desired to advance the workpieces rapidly through the furnace in a step by step manner the above cycle is repeated the required number of times to move the Workpieces the length of the heating chamber I6. In some instances it may be desirable to leave the workpieces i9 in a particular heating zone in the furnace for a certain length of time. This may be accomplished by varying the length of time between operations of the carrier or the vertical support means. This construction has many advantages as are readily apparent to those skilled in the art. It is simple.

The operation of the carrier and supports is positive. Moreover the feed mechanism is relatively inexpensive to manufacture.

While We have shown one embodiment of our invention it Will be understood that we do not wish to be limited thereto since many modifications may be made and we therefore contemplate by the claim to cover such modifications as fall within the true spirit and scope of our invention.

We claim:

In a mechanism for feeding an article to a furnace, the combination of spaced link chains extending horizontally through the furnace, sprockets at opposite ends of the furnace for supporting the chain, pressure fluid means connected to opposite ends of the chains for eiecting reciprocable movement of the portion of the chain in the furnace between preselected positions, a plurality of vertically movable uprights disposed in alined rows, guide means for said uprights, beams extending between adjacent uprights in each row to define a support means having spaced surfaces shaped to engage opposite edges of an article and movable between a retracted position in which the surfaces are below the top of the chains and a raised position in which the surfaces are above the top of the chain, said beams being arranged in end to end relationship with a space between adjacent ends thereof, a first bar pivotally connected to each upright, a second bar pivotally connected to each of said first bars, means for pivotally mounting the opposite end of each of said second bars to be in substantially alined relation with said uprights and to be at one side of the connection between the first and second bars, a driving link for each row of uprights pivotally connected to each first and second bar in each of said rows, and pressure fluid means connected to said links for moving said bars between a position in which the bars are out of alinement and said spaced surfaces are in their retracted position and a position in which they approach alinement to effect vertical movement of the spaced surfaces of said support means to their raised positions whereby upon successive reciprocations of said chains and said support means the article is advanced through the furnace in a step by step manner.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 553,315 Packer Jan. 21, 1896 665,227 Johnston Jan. 1, 1901 1,686,696 Hirshmann Oct. 9, 1928 1,861,492 Culbertson June 7, 1932 1,871,501 De Coriolis Aug. 16, 1932 2,416,763 Lynch Mar. 4, 1947

Images