US1282987A - Hopper. - Google Patents

Description

H. W. TIFFANY.

HOPPER.

APPLICATION FILED JUNE 8. 19!].

Patented. Oct. 29, 1918.

3 SHEETS-SHEET I.

H. W. TIFFANY.

HOPPER.

- APPLICATION FILED JUNE 8. l9li.

Patented Oct. 29, 1918.

3 SHEET SSHEET 2.

H. w. TIFFANY.

, HOPPER.

APPLLCATION FILED JUNE 8. 1911.

Patented Oct. 29, 1918.

3 SHEETS-SHEET 3 flrer w. Tiffany sin ns earn onnion.

HERBERT W. TIFFANY, OF EAST BRIDGEWATER, MASSACHUSETTS, ASSIGNOIR. OF ONE- HALF T0 ARTHUR I. NEGUS, OF EAST BRIDGEWATEB, MASSACHUSETTS.

HOPPER.

Specification of Letters Patent.

' Application filed June 8, 1917. Serial No. 173,442.

Hoppers, of which the following is a specification;

This invention relates to improvements in hoppers. More particularly it is illustrated as it may be applied to a hop er used in an automatic stoking device for eeding coal to a boiler, but it is applicable for many other uses. Although thefunction of a hopper is to discharge its material downward through an opening in its bottom, that opening constitutes only a portion of the entire area of the hopper when considered in horizontal projection. As one or more of the walls adjacent to the opening is inclined, the material that is passing through sometimes forms itself into an arch springing over the dis- I charge opening, from the inclined .wall as a base or impost, and supporting the materia above so that the discharge ceases.

The desirability of providin a mechanical contrivance for rendering t e feed from a hopper regular has long been felt, and various attempts to accomplish that end have been made, but it is believed that none of them have proven capable of successfully accomplishing the desired result under operating conditions. In connection with mechanical stokers, this defect is so seriousthat it is usually. necessary to keep a man ateach boiler Whose duty is to reach into the hopper T with an implement to see that such arches do not form, and to break them if they do form. This both involves labor. cost, and results in a certain irregularity of feeding to the fire because the mechanical devices which handle the coal from the hopper to the fire are by the making and breaking of the arches at one moment-deprived of supply and at another moment flooded with excess. It is the object of the invention to save this labor cost: and to eliminate this irregularity. The use of the invention has been found, in practice, to produce an increase of the output of each boiler and an increase of its efficiency, resulting in more horsepower and more energy being obtained per ton of coal. It is the purpose of the invention to provide these and the other advantages that follow from the construction disclosed. It is intended that the patent shall cover by suitable expression in the appended claims whatever features of patentable novelty exist in the invention disclosed. In the accompanying drawings,

Figure 1 is an end elevation showing an embodiment of the invention applied to a hopper in automatic stoking mechanism, in section on the line 1-1 of Fig. 3;

, Fig. 2 is an end elevation viewed in the same direction of certain details which have been cut away in Fig. 1, but whose plan is seen in Fig. 3;

Fig. 3 is a plan of the apparatus;

Fig. 4 is an elevation, in section on the .line 44of Fig. 3; and

Fig. 5 is a detail of the blade.

As represented in the drawings, the inven-' tion comprises a horizont'ally moving blade, or series of blades, 10 arranged in the bottom of a hopper whose inclined front side wall is marked 11, whose vertical end wall is marked 12, and whose vertical rear wall 15 In the apparatus illustrated a series of rods 20, each operating a plunger 21 guided in a Patented (lot. 29, 191%.

cylinder 22 and projecting thence into and along a valley 19 are driven by the crank shaft 13. The valleys are in the bottom of the hopper, lie horizontally, and receive material down through the hopper, which falls in front of the plungers whenever they are retracted; and the advance movement of each plunger pushes all such material before it through an opening 24 to the grate or other place provided for burning the coal under the boiler, which is indicated diagrammatically in the drawing as by the incline 24'. Theblades 10 extend horizontally parallel to the valleys 19, and are mounted on a rod 14 which has a reciprocating motion horizontally in a direction perpendicular the direction of the valleys, which movement as illustrated is transverse to the direc tion in which the plungers 21 move. The blades are set in the bottom portion of the hopper, close over the crests 29 between adjacent valleys 19 where they are supported on the rod 14, which in turn is there supported in bearings 25 and 251 The bearings 25 consist of suitably shaped cross rods over the valleys having ends 26, 27 turned up at suitable angles for attachment respectively to the front wall 11 and the rear wall 15. These support the rod 14, and are provided with caps which cover and to a degree protect its bearings 25 on them. The rods bearing 25 is in end wall 12 of the hopper. Therod 14 is made to reciprocate in the direction of its length by a bell crank 30 which is pivoted outside of the hopper at 31, on a suitable support, and which is actuated by a connecting rod 32 driven by the same crank shaft 13 which drives the feeding plungers 21. However, the power for moving rod 14: is not great and might be derived from any other suitable source. The device here illustrated for obtaining it from the main crank shaft consists of small crank 33 mounted on the end of the latter. The pivotal support 31 forthe bell crank may likewise be arranged in any convenient way. In the form illustrated it consists of a sheet metal bracket having vertical parts 34 fastened. to the end wall 12 of the hopper, and secured to the adjacent boiler front, and an approximately horizontal part 36, supported by these two. Another bracket 37 rests upon this horizontal part; and a bolt 31 passing vertically through these two horizontal parts constitutes the pivot of the bell crank. Any suitable leverage may be used in the proper designing of these parts to give whatever travel is desired for the rod 14, and whatever strength of thrust is needed.

The blades 10 are fixed on the rod 14. As seen in Figs. 1, 3 and 5 these may be of, simple design. Preferably they are small in cross section, so that they do not interpose much obstruction to flow of material, and yet are broad at their ends, so that each spreads over considerable area. Each blade reaches up along the front wall 11 ,of the hopper, in position to cut the arch of material which is based thereon, if any there be, just above the place where it springs from thatwall at a place'comparable to the skewback of an 'arch. By making the varm 10 with two prongs in this place, as marked 10, the blade in its travel actually covers twice as much surface of the front wall as if there were but a single prong; and it is obvious that by adding more prongs a relatively larger area may be covered. The prongs 10 may be so arranged with relation to the extent of travel that they cover all parts of the length of the hopper wall during one complete to and fro stroke of the rod 14; but in an installation of the invention for feeding coal it has been found unnecessary to have so complete a covering of the base on which arches may form. This construction is illustrated in Figs. 2 and 3 where consideration-of the distance of travel which,

would result to these prongs 10' from a complete turning of the crank shaft 13 will show that neither prong 10 reaches the area traversed by another. The end of theblade 10 next to the rear wall of the hopper has two arch of material would be supported if any were formed, if there were no bottom slope 15 it might be thought that in such a case these inner ends of the blades are useless. However, they and the part of the main body of the blade 10 which is on their side of the rod 14:- serve to sustain pressure from the descending mass of material in the hopper which balances the similar pressure of material on the prongs 10 and the parts of the blades, 10 which are on the other side of the rod 14.. Hence all tendency of the rod 14 to turn on its axis is eliminated. Also friction of the prongs 10 upon the closel adjacent surface of the wall 11 is. eliminate by thus eliminating their tendency to sag into contact with that surface. The shape illustrated at 10 proves effective in practice to prevent formation of an arch on the inclined lip under it marked 15.. As the blades keep the material moving downward, they have material below them as well as above them, and, in fact, are embedded in it. Hence the downward pressure of material upon them is practically balanced, as is the downward pressure on an object immersed in a liquid. Floating thus to and fro over the inclined Wall 11 of the hopper, and over the inclined lip 15 they are in po-" sition to cut at its skew-back any arch of material, that forms in the mass of material, z'. a. just above the place where the arch springs from the wall or incline as an impost. They may, however, if preferred, be so located elsewhere as to cut any archof material springing therefrom, as for example, the blades may rise from a central position to cut a high part of such an arch based on the side of the hopper. In any event the prongs 10' may run up far enough to reach into'and through-the arch. The motion of these blades may be very slow. As the blade and its prongs move along, cutting through material in the arch, the adjacent material is so loosened that it falls; and that allows other material of the arch to fall. This action proceeds rapidly enough so that the arch is broken before the plunger belowhas time to complete an empty stroke; and no plunger stroke fails to deliver coal to the furnace. Any arch across a Valley 19, springing across it in the longitudinal direction of the rod 14, is also destroyed by the blades 10.

means? In Fi 4 of the drawing is indicated a shape w ich such an arch across a valley may be supposed to take, although it must be understood that the height and shape of such arches may not be precisely known, and that in fact they vary greatly and constantly depending upon the varying moisture and other qualities of the material that is being handled, and that when the apparatus of the invention is 'used they probably do not "really form at'all but are prevented from forming by the action of the apparatus. In the case selected for illustration, the arm 10, which is shown in mid position of its travel, moves out to the right over the right hand valley, and in so doing slices the arch (assuming one to be there) and pushes material bodily out of it with the result that otlller material therein loses its support and fa ls, asmuch as the material delivered by a plunger at a single stroke is so much less than the whole material below the level of a blade 10, it seems probable that the device of the inventionv is effective to break arches much smaller than that pictured. This probably results from the disturbance which it sets up in the adjacent material, and the displacing pressure which it applies to portions of that material, causing the arch to be broken down because its pressure overcomes the friction between particles of the material and produces enough slip in the mass to break the arch, even though operating above it.

When the apparatus is not used an arch part of this arch, and whose prongs 10 work breaking in its sides sufliciently so that the whole would fall. The rod 14 might be worked by hand; but as it is customary to feed coal that is pretty wet the arches are liable to form at any time, and their existence is. not noticeable from the outside, So that it is better to have the apparatus constantly driven by power. It is found by actual use that in mechanism such as that illustrated, in which there is a movement of a blade in direction to break an arch at least as oftenas each withdrawal of a piston occurs, the feeding of material is made constant with an observable and important economy in the quantity of coal consumed in producing the measured power output of the boiler.

Apparatus heretofore proposed for the purpose of the invention has been found to make ahole for itself in the material, and then to travel idly in that hole, the main flow whereupon the whole arch falls. In-V travel of a blade runs into the path of necesagainst another part of it, would result in' sary flow of material to the discharge, intermittently, so that the material which it has displaced on any stroke is automatically replaced by other material during its absence, with the result that on its next stroke the arm findsa body of material on which to act, instead of traveling idly.

The connection between connecting rod 32 and the reciprocating rod 14 as illustrated embodies an extremely simple and useful device in that the friction, with incidental wear and need for lubrication, of a universal joint is avoided. This is accomplished by providing a clevis 38 on the end of the connecting rod 32 the prongs of whose fork stand a little farther apart than the thickness of the end of the bell crank 30, which stands between the prongs and which is secured thereto by the bolt 39. The top and bottom sides of this bell crank have bosses where the hole passes through it for the bolt 39, high enough to keep the clevis from hitting the edge of the bell crank; and the hole for the bolt 39 through the bell crank 30 is a trifle larger than the diameter of that bolt. In use the clevis and bolt rock slightly on the end of the bell crank as the crank 33 passes from one side to the other of its circuit. The motion is so slow, and the angle of swing so small that no difliculty is experienced in operation; and because of this substitution of rocking or rolling connection for the rubbing of a pivot which characterizes an ordinary universal joint, the need for the carefully made bearing surfaceand continuous lubrication of such is avoided.

I claim as my invention 1. The combination of coal feeding apparatus, including a relatively long and narrow trough hopper extending horizontally, adapted to hold a supply of coal adjacent to the furnace of a steam boiler, having openings at its bottom through which coal passes out from it to the boiler furnace and having interior surfaces whereon an arch of coal may rest, with a movable coal-displacing element, and means supporting and guiding said element in position to act directly on coal along substantially" the whole of a line crossing transversely any arch that might rest on said surface.

2. The/combination of coal feeding apparatus, including a relatively long and narrow troughhopper extending horizontally, adapted to hold a supply of coal adjacent to the furnace of'a steam boiler, having openings at its bottom through which coal passes out from it to the boiler furnace and having interior surfaces whereon an arch of coal may rest, with a movable coal-displacing element, and means supporting and guiding said element. in position to act directly on coal with a horizontal stroke to and fro in the direction of the length of the trough in position and direction to traverse substantially the whole of a cross section through any arch that might rest on said surface.

3. The combination of coal feeding apparatus, including a relatively long and narrow trough hopper adapted to hold a supply of coal adjacent to the furnace of a steam boiler, having openings at its bottom through which coal passes out from it to the b( ler furnace, and having interior surfaces whereon an arch of coal may rest, with a coal-displacing element extending horizontally along said surfaces, and means supporting and guiding said element in reciprocating movement horizontally so as to cut substantially the whole of a cross section through any arch that might rest on said surfaces.

4. In a hopper having in the vicinity of its discharge place an interior surface whereon an arch of contained material may rest, the combination therewith of a displacing element arranged over and parallel to said surface and extending horizontally along it,

and means whereby said element is movable horizontally out from and in toward said surface, through the position occupied by any arch resting on said surface.

5. In a hopper having in the vicinity of its discharge place interior surfaces extending in directions perpendicular to each other, whereon arches of contained material may rest; the combination therewith of a displacing element movable with a stroke which at times causes it to be in positions within the body of material constituting any such arch, moving in its said stroke horizontally to and fro parallel to one of said surfaces and out from the other of said surfaces, thereby displacing material of an arch resting on either of them.

6. In a hopper having in the vicinity of its discharge place an interior surface whereon an arch of contained material may rest, the combination therewith of a rod passing horizontally into the hopper near the level of said surface; a blade supported on the rod above the said surface and mounting means whereby the rod may be,moved longitudinally; said blade being thereby sliced horizontally through material in the hopper.

7 In a hopper having the general form of a trough with a plurality of lateral discharge openings in its bottom, and means for pushing material in its bottom through said openings, and having inclined surfaces leading thereto, the combination therewith of a rod extending horizontally along the trough; blades thereon arranged 'over said surfaces;

and means whereby the said rod may be given a reciprocating movement the blades thereby displacing material in the hopper.

H. In a hopper having in the vicinity of its discharge place an interior surface where- .on an arch of contained material may rest, the combination therewith of a rod passing horizontally into the hopper near the level of said surface; a blade supported on the rod above the said surface and mounting means whereby the. rod may be moved longitudinally; said blade being thereby sliced horizontally through material. in the hopper: power driven means discharging the material; and a connection therefrom driving said rod.

' 9. In a hopper having in the vicinity of its discharge place an interior surface whereon an arch of contained material may rest, the combination therewith of a rod passing horizontally into the hopper near the level of said surface; a blade supported on the rod above the said surface and'mounting means whereby the rod may be moved longitudinally; said blade being thereby sliced horizontally through material in the hopper; plungers and a crank shaft driving them to discharge said material; an auxiliary crank on said shaft; and a bell crank connection therefrom driving said rod.

10. In a hopper having in the vicinity of its discharge place an interior surface whereon an arch of contained material may rest. the combination therewith of a blade having a narrow body and broad end con'iprising prongs separated from each other and overlying said surface; and means for moving the blade to and fro transversely of the prongs, whereby substantially the whole of said surface'is traversed by one or another of said prongs with relatively little movement.

11. In a hopper having in the vicinity of its discharge place an interior surface whereon an arch of contained material may rest, the combination therewith of a blade having a narrow body and broad end compris ing prongs separated from each other and overlying said surface; and means for moving the blade to and fro transversely of the prongs; said surface and said prongs being inclined, and the prongs sustained out of contact therewith and moving parallel to it. 12. In a hopper, having in the vicinity of 1ts dlscharge a surface on which an arch of material may rest, the combination therewith of a rod passing horizontally into the hopper near the level of said surface; a blade supported on the rod and projecting to both sides thereof, with its surfaces on opposite sides thereof approximately balancing each other, and adapted to pass edgewise horizontally through the material.

13. In a hopper having the general form of a trough with a plurality of discharge places; the combination of cross bars fast to its walls, within the lower part of the hopper and near itsdischarge place; a rod extending along the trough, having bearings thereon; and blades fast on the rod; the Whole adapted and arranged for the rod to have a reciprocating movement in the direction of its length, with the said blades displacing material in the hopper over the edges of said discharge places.

14. In a hopper having in the vicinity of its dischargeplace interior surfaces whereon an arch of contained material may rest, and means discharging material from under said arch position; the combination therewith of a blade extending substantially horizontally across the hopper and adapted to act on material in the arch that may rest on said surface; and means supporting said blade and guiding it with movement to-and fro in a line whose direction passes through said position of material and a position under said arch where material is unsup-- ported by the arch.

15. In a hopper having a plurality of valleys in its bottom leading to discharge openings, the combination therewith. of blades arranged over the crests between said valleys, and means. whereby the said blades may be intermittently moved thence over the said valleys, thereby displacing material.

16; In a hopper having a plurality of valleys in its bottom leading to discharge openings, the combination therewith of means located at the crestabetween two valleys to displace material from the crest toward the valleys.

17. In a hopper having in the vicinity of its discharge place interior surfaces whereon arches of contained material may rest, and 49 a laterally acting, reciprocating feeding plunger displacing material from beneath said arches; the combination therewith of a blade arranged over said plunger, having a part extending in a direction parallel to said plunger and movable in a direction transverse to the direction of movement of said plunger and provided with projecting portions at its ends which move with it in advance of its main body, thereby, in case of 50 an arch extendingin the direction of its movement, undermining the bases of any arch which extends across its direction of movement and which constitutes the base for said arch that extends in the direction of movement of said element.

Signed by me at Boston, Mass, this 19th day of May, 1917.

HERBERT W. TIFFANY.

Witnesses:

ARTHUR I. NEGUS, 'JosEPH T. BRENNAN.

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