US2428887A - Apron type feeder - Google Patents

Description

Patented Oct. 14, 1947 APRON TYPE FEEDER Alexander L. Munro, Milwaukee, Wis., assignor to Smith Engineering Works, Milwaukee, Wis., a corporation of Wisconsin A plicat on February 23, 1945, Serial No. 579,442

The present invention relates in general to improvements in the art of transporting material in bulk, and relates more especially to improvements in the construction and operation of endless feeders of the apron type.

The principal object of my invention'istoprovide an improved apron type feeder which is simple. and durable in construction, and which is moreover highly eflicientin use.

Ithas long been customary in many industries, and especially in the mining and crushing arts, to utilize so-called' apron feeders for the purpose of continuously transporting diverse materials in bulk from place to'pla'ce. The prior apron type feeder ordinarily comprises an endless series of swingably interconnected flights cooperating to form a constantly advancing approximately horizontal deck upon one end of which the bulk materialis deposited and from the opposite end of which th material is discharged by gravity. In order to prevent the advancingmaterial from dropping off of the sidesfof the travelling deck, the flights were sometimes provided with side walls which in some cases were adapted to coact so as to prevent sagging of the transporting stretch or deck of the conveyor; but none of these prior apron feeders incorporated proper provision for adequately protecting the pivotal connections between the successive flights, for preventing material from dropping through the upperdeckonto the lower return stretch, and for'resisting distortion due to excessive loading of the material supporting deck. The prior feeders of this type were also relatively complicated and could not be'durably and conveniently manufactured at mode-rate cost, thus making them objectionable for diverse reasons;

It is therefore a more specific object of the present invention 'to provide an improved endless apron-feeder which overcomes the various objections above referred to; and which is adapted to be readily manufactured and assembled as a compact and effective feed unit.

Another specific object of this invention is to provide an improved flight structure for apron feeders, which may be easily constructed by ordinary casting methods and with minimum machining, and which is moreover built to positively prevent fine particles of material from dropping through the material transporting deck during normal, use of an assembled group of the flights.

A further-specific object of my invention is to provide a simplified castmetal conveyor flight which while beingrelatively light in weight, is exceedingly durable and rigid in construction thus adapting these flights, to effectively resist bending and other distortion due to excessive loadingof feeders embodying these flights,

Still another specific object of the present invention is to provide an improved endless conveying unit adapted'to effectively transport diverse relatively heavy mixed fine and coarse materials of various kinds, which presents an attractive and highly finished appearance, while requirr ing minimum power during normal efficient use thereof.

These and other specific objects and advantages of the invention will be apparent from the following detailed description.

A clear conception of the improved features involved in my present invention, and of the mode of constructing the improved feeder flights, of assembling the same, and of operating the'azsembled feeder units, may be had by referring to the drawing accompanying and forming a part of this specification in which like reference characters designate the same or similar parts in the various views.

Fig. 1 is a perspective view of one of my improved endless apron type feeder units, looking toward one side and the discharge end thereof;

Fig. '2 is an enlarged fragmentary top view of several successive pivotally connected flights of the apron feeder, showing fragments of the pivot shafts which swingably interconnect the flights and also showing the driving collars carried by these shafts; and

Fig. 3 is a partial side elevation and section through the flights of Fig. 2, showing one flight in elevation and two others in section taken just inside of the adjacent side walls, and also showing one of the deck supporting rollers coacting with the lower edges of the flight side walls.

While the invention has been shown herein as being advantageously applicable to apron feeders of the endless type especially adapted for heavy loading, it is not my desire or intent to unnecessarily restrict the scope or utility of the improvement by virtue of this limited disclosure.

The improved apron feeder shown in the drawing by way of illustration, comprises in general an endless series of sturdy flights 5 swingably interconnected by means of pivot shafts 6 and adapted to be driven by sprocket wheels 1 coacting with rotatable collars 8 carried by the protruding opposite ends of the shafts B, so as to cause theupper approximately horizontal stretch or deck 9 of the endless series, to constantly advance in a predetermined direction, as clearly shown in Fig. 1. Each of the flights 5 is preferably formed of some suitable wear resistant material such as cast manganese steel, and consists primarily of a transversely elongated imperforate flat deck portion or body l0 having integral upstanding flanges or walls I I at its opposite sides, and being provided with integral hub portions l2, [3 at its opposite ends and beneath the body H! which have holes for pivotal coaction with the shafts 6. The front hub portions l2 of each flight 5 are spaced apart for the intervening reception of the similarly spaced rear hub portions l3 of the next adjacent or following flight of the series, so that the cooperating hub portions l2,- l3 of each set form an uninterrupted hub extending throughout the width of the feeder; and the upper or outer faces of the flight bodies iii are additionally provided with local integral return guide ribs it, while the lower portions of these bodies are moreover provided with longitudinal and transverse integral re-enforcing ribs l5 connecting the hub portions l2, l3 as well as each other, see Figs. 2 and 3.

The integral side walls H of each flight 5 are provided with offset trailing end portions it which are adapted to overlap the adjacent side walls l i of the adjoining flights 5 in order to avoid gaps between these adjacent walls when the flights proceed around a bend, and when the flights 5 are travelling along the upper stretch 9 of the apron, the front upper ends of the side walls ll of each flight are adapted to contact abutments i! formed at the junctions between the rear ends of the side walls and the trailing portions 16 of the adjacent flights, thereby maintaining the stretch or upper deck 9 in straight line condition and preventing downward sagging thereof. How ever, in order to relieve the shafts 6 from excessive stress due to loading of the stretch 9, the lower edges l3 of all of the side walls l l are formed for rectilinear alinement with each other when active, and sup-porting rollers l9 are caused to contact these straight wall edges at intervals, as clearly illustrated in Figs. 1 and 3.

In accordance with my present invention, the front end of each flight 5 is also provided with an integral curved lip 2ft extending entirely thereacross between the opposite side walls ll thereof and forming an arcuate recess 2| extending entirely across the endless feeder above the front hub produced by the cooperating portions l2, l3;

and the rear end of each flight is furthermore provided with an integral arcuate rearwardly overhanging tongue 22 extending from one side wall trailing end portion 15 to the other, see Fig. 3. The tongues 22 are adapted to snugly fit within and to articulate in the recesses 2! of the adjacent flights 5 when the endless apron travels about its bends, and besides materially strengthening and re enforcing the flights against possible distortion and sagging, the curved lips 29, tongues 22, recesses 2i positively prevent material from dropping through the upper deck 9 of the endless conveyor, and thus protect the shafts e from excessive wear. The individual flights 5 are therefore formed of great strength, and may be readily produced of durable steel by casting and without requiring costly, machining for their ultimate completion.

The collars 8 are freely rotatably mounted upon the projecting ends of the pivot shafts S, and the driving sprockets l which are adapted to engage these collars 8 as indicated in Fig. 1, are mounted upon driving and idler shafts 23, 24 respectively mounted in suitable bearings 25 carried by a main supporting frame 26. The front driving shaft 23 also carries a gear 2']! which meshes with a driving pinion 23; and the supporting rollers is which coact with the lower edges i8 of the flight walls i l of the upper stretch 9, are also journalled in bearings 29 mounted upon the frame 26 and pass transversely through the endless apron between the upper and lower stretches thereof. In order to prevent excessive sagging of the lower idle stretch of the endless apron, the return guide ribs M which are formed integral with the outer surfaces of the flight bodies ill, are caused to smoothly coact with local sag preventing rollers 38 which are likewise carried by a shaft 31 journalled on the main frame 26, so that the entire apron assemblage constitutes a unit all parts of which are associated with the common frame 25,

As previously indicated, the individual flights 5 because of their simplicity may be readily constructed of durable steel or the like by ordinary foundry methods, and no machining whatever is required for their production since the openings or holes in the hub portions l2, l3 and which ultimately coact with the pivot shafts 6, may be formed by coring. After proper construction and finishing of the flights 5 so that all flights of a predetermined type are interchangeably similar,

any desired number of the unitary finished flights may be assembled into an apron feeder of any suitable length and mounted upon a frame 26 as depicted in Fig. 1. The feeder assemblage may thereafter be operated at will by applying power from the driving pinion 28 to the gear 2". and drive shaft 23; and during normal operation of the feeding unit, the successive flights 5 of the endless series will constantly advance along the upper deck 9 in approximately horizontal and rectilinear formation, and will effectively convey bulk material from left to right as viewed in Fig. l, eventually delivering the mass of material over the discharge end of the structure laterally adjacent to the gear 27.

During the advancement of the flights 5 along the upper deck 9, the abutments I 'l of the side walls ll of the leading flights cooperate with the front ends of the side walls H and with the forwardly advancing lips 20 of the adjacent flights to prevent sagging of the upper stretch or deck 9 and to also relieve the pivot shafts 5 from excessive pressure, due to loading. The local supporting rollers l9 which coact with the lower rectilinear edges [8 of the side walls I I, also serve to prevent sagging of the advancing upper deck 9, but since the arcuate lips 29 and the curved tongues 22 assist the abutments H in performing their function by preventing possible spreading of the portions of the side walls H which are integrally united by these lips and tongues, only relatively few if any of the rollers H) are necessary. The coacting lips 21] and tongues 22 besides aiding in the prevention of this sagging, also greatly enhance the transverse strength of the bodies I0, and furthermore positively prevent finer material from dropping through the upper conveying deck 9 onto the shafts 6 and the lower return stretch of the endless apron. During rearward travel of this lower stretch, the local rollers so located beneath the apron, coact with the outer guide ribs M of the successive flights 5, and thus also relieve the shafts 6 from excessive pressure due to sagging of the return stretch; and the rear portions iii of the side walls I I of the leading flights 5 overlap the front portions of the opposite side walls of the succeeding flights so as to eliminate side spillage of loose material. When the successive flights 5 travel around the end bends, the rearwardly extending side wall overlapping portions it also prevent the formation of gaps at the sides of the conveyor, and the lips 2i) and tongues '22 should also be of sufflcient length to prevent the formation of openings between the adjoining flights 5 at the bends.

From the foregoing detailed description of the construction and operation of the improved assemblage, it should be apparent that my present invention provides an improved apron feeder wherein the flight may be readily manufactured by ordinary foundry methods and at moderate cost, to produce extremely rigid, durable, and efficient individual and assembled flight units. Each of the improved flights 5 constitutes a unitary structure which is interchangeable with all others, and when a group of the flights is assembled, a self-sustaining and impervious material carrying and transporting deck 9 results. The coacting arcuate lips 20 and tongues 22 of the pivotally connected flights 5, not only serve to prevent fine material from dropping through the conveying deck, but also firmly unite the opposite side walls II and overlapping portions 16 of each flight 5 and furthermore re-enforce the flight bodies l0 and prevent possible distortion thereof. The cross ribs l5 and the guide rib l4 additionally strengthen the bodies l0, and the side walls II and projections 16 formed integral therewith function to effectively confine the bulk material upon the conveying surface and prevent lateral spillage. The improved flights 5 may be manufactured in diverse sizes and shapes in order to meet varying operating conditions and capacities, and if produced by casting, they require minimum machining and are relatively inexpensive. The improved apron feeder has proven highly satisfactory and eflicient in actual use, may be constructed of relatively light weight but of great strength, and presents a neat and highly finished final appearance as will be apparent from Fig. 1.

It should be understood that it is not desired to limit this invention to the exact details of construction or to the precise mode of operation herein shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the art.

I claim:

1. An apron feeder, comprising, a series of articulably end connected unitary flights each having a flat body provided with integral upstanding side walls projecting rearwardly beyond the body and coacting with the walls of adjoining flights to provide endless flight supporting edges, each flight also having an overhanging tongue formed integral with and spanning the space between said rearwardly projecting wall portions, the front portion of each body also being provided with a continuous arcuate recess for the snu reception and articulation of said tongue of an adjacent flight therein, supporting rollers for said series rotatable about fixed axes and coacting with said wall edges, and advancing collars for said series carried by said flights outwardly beyond said walls.

2. An apron feeder, comprising, a series of end connected unitary flights each having a body provided with integral upstanding opposite side walls adapted to abut against the walls of adjoining flights to provide continuous flight supporting edges, said walls of each flight being integrally connected by an arcuate overhanging tongue extending across the trailing end of the body, said body also being provided at its front end with an arcuate recess for the snug reception and articulation of said tongue of an adjacent flight therein, supporting rollers rotatable about fixed axes and coacting with said wall edges, pivot shafts connecting the successive flights, and advancing c01- lars for said series carried by the outer ends of said shafts outwardly beyond said flight walls.

3. An apron feeder, comprising, a series of articulably end connected unitary flights each having a flat body provided with integral upstanding side walls projecting rearwardly beyond the body and adapted to overlap the walls of adjoining flights to provide endless flight supporting edges, each flight also having a rearwardly extending tongue formed integral with and spanning the space between said rearwardly projecting wall portions, the front portion of each body also being provided with an arcuate recess for the snug reception and articulation of said tongue of an adjacent flight therein, supporting rollers for said series rotatable aboutflxed axes and coacting with said wall edges, and advancing collars for said series carried by said flights outwardly beyond said rearwardly projecting Wall portions.

4. An apron feeder, comprising, a series of end connected unitary flights each having a body provided with integral upstanding opposite side walls projecting rearwardly beyond the body and adapted to abut against and to overlap the walls of an adjoining flight to provide continuous flight supporting edges, the rearwardly projecting portions of said walls of each flight being integrally connected by an arcuate tongue extending across the trailing end of the body, said body also being provided at its front end with an arcuate recess for the snug reception and articulation of said tongue of an adjacent flight therein, supporting rollers rotatable about fixed axes and coacting with said wall edges, pivot shafts connecting the successive flights, and advancing collars for said series carried by the outer ends of said shafts outwardly beyond said rearwardly projecting wall portions.

5. An apron feeder, comprising, a series of articulably end connected unitary flights each having a body provided with integral upstanding opposite side walls adapted to abut against and to overlap the Walls of an adjoining flight to provide continuous flight supporting edges and a continuous intervening material confining trough, said walls of each flight being integrally interconnected by an arcuate rearwardly extending tongue extending across the trailing end of its body, the body of each flight also being provided at its leading end with an arcuate recess for snu reception and articulation of said tongue of an adjacent flight therein, supporting rollers rotatable about fixed axes and coacting with said wall edges, pivot shafts articulably connecting the successive flights near said tongues and recesses, and advancing collars for said series carried by the outer ends of each of said shafts outwardly beyond said flight Walls.

ALEXANDER L. MUNRO.

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

UNITED STATES PATENTS Number Name Date 711,993 Mason Oct. 28, 1902 886,343 Bevan May 5, 1908 1,804,423 Krenze May 12, 1931 1,854,334 Jensen et al. Apr. 19, 1932 FOREIGN PATENTS Number Country Date 561,616 Germany Oct. 15, 1932

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