US1583027A - Stoker bar - Google Patents

Description

'May 4 1926.

e. H. THACHER, JR

STOKER BAR File?! Oct. 9. 1925 2 Sheets-Sheet 1 6. H. THACHER, JR

STOKER BAR Filed Oct. 9, 1923 2 Sheets-Sheet 2 Ina/en??? eHThac fiwzqyaww G005 fiy ug Patented May 4, 192.6.

STOKER A p 1,583,027 UNITED STATES. ,LPATENTOFFICL GEORGE 1r. rrraonnn, an or rinrnosn, MASSACHUSETTS.

BAR.

Application filed October 9, 1923; Serial No. 667,514;

To a?! whom it may concern Be it known that Gnonon li-Trraorrnn, n, a citizen of thc United States, and a resident of Melrose, in the county of Middlesex and State of lrfassachusetts, has inventedan Improvement in Stoker Bars, of which the following description, in connecnection with the accompanying drawings, 18 a specification, like characters on the drawings representing like parts.

The present invention relates to furnaces and great surfaces therefore and particularly to the type known as hand-stokers wherein combustion takes place upon. an inclined fuel. surface composed of a plurality of transverse great or stolier bars. The invention aims to provide a novel and in1- proved stolrer bar and grate surface therefor, and will best be understood from a'description of one selected embodiment thereof, refcrencebeing had to the accompanying drawings illustratin the same, and wherein,

Figure 1 is a top plan view of the stoker bar, being one of a series of like bars;

Fig. 2, a detail perspective side'view of the same, all but one of the grate sections having been removed; y

Figs. 3 and a transverse vertical sections of the stoker bar frame from which the grate sections have been removed, on the lines and l-& of Fig. 1, showing the inner faces of the end plates. respectively,

Fig. 5, a rear face View of the removable cross bar between the endv plates for supporting; the grate sections; v

Fins. 6 7 and 8 vertical sectional views 3 o 7 1 1 n of the removable cross-oar on illG'llllES 6o,

77, and 8-8 respectively of Fig. 5;

Figs. 9 and 10, detail longitudinal sections of portions of the stoker bar showing the extremities of the removable cross-bar;

Figs/11, 12 and 13 top, rear end. andsidee views respectively of'a grate section on an enlarged scale.

Referring to the drawings, the StOliGl bar herein shown and illustrating one selected embodiment of my invention, is designed to be used in a furnace "of the hand-stoking type and of the general.character shown in my United StatesPatents Nos:1,302,453 and 1,453,482, wherein a plurality of stolrer bars are mounted to rock on inclined bearing-.

bars extending from the front to the rear of the furnace and whereinthe stoker bars are connected together usually 'in two series, to rock independently, thereby. to advance l7 and on the front, side by a: curved shield 18. The outer face of each end plate has a trunnion 19 adapted to seat in a recess in the bearing-bar on the corresponding side of the Stoker for supporting" thefstoker bar,

these trunnions being so positioned that" when the stoker bar is rocked its front side, including'the shield 18, swings above the top surface of the stoker. I

The shield 18 is provided witha number oftransveise apertures 20, 20 etc. distributed preferably at regular intervals over its surface to permit the passage of air. therethrough and also into the fuel bed when the stoker bar is rocked. One or more of these apertures may receive bolts, Qlfor connecting alug 22t-o one end of the shield, byineans of which the bar is operativelyconnected to actuating mechanism. This lug is provided with an upper portion ,3 having-the same curvature as the inner face of the shield and is providedwith holes arranged to register with holes in the shield: at the point of attach nent. Those openings; in the shield whicl are utilized for this purpose are p1eferably countersunktoreceive the bolt heads which lie flush with the outer face of the shield to avoid projections interfering with theoperat-ion of the Stoker bar. 1 The upper edgeof the shield 18 has a flat surface. which forms a straight supporting ledgeor seat 2 f on which the front ends of the gratesections 25, 25, e tc..are arranged to ion lap in movable relation, this'ledgeor seat being disposed well belowthe upper surfacev cf'thc stoker and at a depthcommensurate with the overly ng portions of the grate see trons which lie flush with all theremaining grate'sections constituting the upper face of.

ing the end plates 15, 16, but without any positive locking connection and free to be lifted out of and restored to its normal position within the frame. This element is designed to provide a firm support for the grate sections, being free to expand or contract under changing thermal conditions without warping or cracking but movable in respect to one end plate only during such expansion and contraction.

, The top of the bar forms a flat supporting surface 2'? substantially parallel with the top surface of the grate sections, while the sides are arranged at an inclination to each other dueto the gradual thickening of the bar in cross-section, proceeding from top to bottom, at which point there is provided on the rear side a slight reinforcing lip or web 28 extendingapproximately the entire distance,

between the end plates and designed to prevent warping of the bar lengthwise. The extremities of the bar extend freely into recesses provided on the inner faces of the end. plates, one of these recesses forming an enclosed socket 29 conforming generally in outline to the corresponding end of the crossbar which is introduced therein as the first operation in placing the bar in position on the frame. The bottom wall of this socket forms a ledge on which the cross-bar rests and is preferably extended outward by the provision of a shoulder 30 at the same elevation on the inner face .of the end-plate. This extension or shoulder is adapted to serve initially as aguide to insertion of the bar into the socket and also to insure prevention of downward displacement of the bar during rapid or excessive contraction of the bar from any cause.

The opposite end of the supporting bar carries a head 31 conforming generally in outline to an obliquely arranged slot or re cess 32 in the corresponding end plate 16, said slot communicating at its upper end i with the top edge of the bar and at its lower end with a well or recess 33 into which a reduced portion 35 on the bottom of the head 81 freely extends, said reduced portion being adapted to operate as a stop for preventing lengthwise movement of the bar at this end during expansion and contraction. This construction tends to prevent ash from lodging in the recess 32 and, by inducing greater relative movement in the bar, also serves to prevent adherence or pinning of the grate sections to the bar due to fusion or clinhersfand consequent warping effects.

The diagonal position of the head 31 cooperates with'the grate sections 25 as hereinafter more fully explained, to prevent upward or outward displacement of the bar 17 when the stoker bar is rocked. This end of .tention 44 (see Figs. 2 and 13) having the bar 17 bears movably upon a horizontal. support formed by the upper edge of an in tegral lateral extension portion 35 of the end plate 16 and extending across the lower end of the slot 82 and enclosing the well 38 (see Fig. 10). A sui cient clearance is provided on all sides of the head 31 to'allow for necessary expansion.

Each of the grate sections has a grated upper surface for fuel support formed of a number of spaced longitudinal members 40 connected together at one end by an integral transverse member ll and at the opposite end by an integral transverse member 12. liach of these transverse members projects at both ends beyond the sides'of the grate section a distance preferably somewhat less than half of the space between adjacent longitudinal members so that when the sev; eral grate sections are all arranged in normal operative position a slight space will intervene between corresponding ends of adjacent sections while the spaces between the outer longitudinal elements 40 of one grate section and the corresponding elements of another section will be substantially of the same width as the enclosed openings of each grate section.

The grate sections 25 are all slidably mounted in theframe on the bar 17, the front ends of the sections being extended forward to lap onto the upper edge 2 1 of the shield 18, which is thus provided with an upward extension and a protective covering from the fuel bed. The upper surface of the grate sections is designed to lie flush with the tops of the end- plates 15, 16 while, the front face conforms to the are of the outer face of the shield. The two outer longitudinal members 40 are each provided. at the rear end, which is toward the lower end of the furnace, with a downward e1;-

Iuu

transverse tapering cleft- 43 extending well upward into the body portion of said members and nearly commensurate with the height of the bar 17, which extends into it. These clefts or slots form a channel of sufficiently ample proportions to allow a clearance of adjacent parts at all times, to the end that the grate sections separately or collectively may be free to be removed from and restored to their setting in any state of temperature, and, also, that their. resulting free, play may tend to discharge ash sifting down from the fuel bed. V

The jaws formed by the lower extremities lit) ' ofv the extensions at are directed against and impinge upon bar 17 during the stolnng by fuel or clinkers penetrating between the i139 grate sections and the shield during the stolr-ing process. Occasionally at such times one or more of the grate sections may be slightly lifted from its setting, but complete displacement is prevented by the effective resistance offered by the impingement of the iaws of the lower portion 44 upon the bar 17 as before stated. Hence, while the grate sections are at all times movable witlrrespect to each other and free to be removed from normal position by a direct upward pull, their displacement by force exerted bedded in the stoker surface, the channels.

or interstices between said teeth being adapted-to admit air to the fuelbed.

In assembling the parts of the stoker bar,

. the supporting bar 17 is first mounted in position on the end plates. In so doing one end of the baris first inserted in the recess 29 and then the opposite end bearing the head 31 is dropped into place. The grate sections are now placed separately in position until the entire space between the end plates is filled. TlIQSB'SQCtlODS' may be removed in like manner when necessary, being carried on the bar 17 without any locking connect-ion whatevervand free to expand or contract in any direction. 1

The weight of the fuel tends normally to maintain the gra-tesections in position while any-force applied by the fuel upon the front end of the grate sections during the upward or downward swing of the bar, tending to'dislodge the grate sections or lift the supporting bar out of place, is success fully opposedwith respect to the former elements in the mannerliereinbefore relatcd, and also with resp ct to the latter element by reason of the angular position of the head 81, to remove which force must be ap-plied'in the line of the head and the recess in which it rests, this being in. a direction opposite to that 'of'the force exerted by the dislodging fuel.

' It is quite usual for grate bars to wear, Juin out or crack at some specific pointor points in their fuel area and not uniformly at all points. This is attributed to excess of heat at localized spots or, what is more generallythe case, to improper or'unequal distribution of the metal, so that expansion or contraction takes place more rapidly at one point than another, thus resulting in undue internal strains which cause warping tive position.

and rupture. With the present device-these objections are largely overcome. The provi sion and arrai'igement of air cooling passages is so co-ordinated with the weightand'thic-kness of the surrounding metal that expan-j sion and contraction ofeacli of the grate sections at all points may be accomplished without '1n]ury, while the overlay of metal directly above the shield 18 and the sup-J porting bar 17 is adequate to prevent orerlieating'and warping of these parts. I

It should be understood that the present invention is not restricted to the particular embodiment herein shown, and that obvious modifications maybe made therein without departing from the scope of the invention. Iclaim. as my invention l '1. In a rocking stoker bar, in combina tion, a frame having end plates, a member connecting the end plates "and forming-a shield adapted to swing above the upper face of the stoker when the sto-ker bar is rocked, a series of free grate sections mounted in the frame and normally movable in their operative position, a carrier bar'carried on said end plates, and furnishing support for the grate sectio'ns,said grate sections'being' independently removable and said carrier bar and grate sections being free lobe removed together and restored to operative position in the, frame, and nonlocking retaining means for securing the carrier bar in operative position when the stoker'bar is rocked. i g V Ina stoker bar, incombinatiomja frame having end members, and a member connecting-the-end members and foriiiinga shield on the front side of the fra ne, a series of grate sections 'inovablyunounted in the, frame, a fr-eely removablefcarriei" bar carrie'd on said endmembers and furnishing J I support for the grate sections, each of sa'id g'rate'sections being-free to be lifted out of and restored to operat ve position without disturbing the positionof the frameor carrier bar, and;

o'n-locking retaining means normally secui 1g the carrier bar in opera- 3. In a rocking stolrer' bar, combinat1on,'-a frame with? end members each ha-vmg afrecess on its inner face, one of such recesses formmg a-sock-et and the remaining recess forming a' ch'an'nelcommunicating with the top edge of the respecti ve'end member, acarrier bar (ttllllGCl on said'end members-and extending at opposite ends into'saidrecesses, a' member-'connecting the end mem bers on the front side of the frame and forming a shield, and a freely removable grate portion mounted in'the frame and receiving support from the carrier bar, the front end of said grateportion being arranged to lap onto and cover said shield.

4. In a rocking Stoker bar, in combination, a frame having end plates, a member connecting the end plates and forming a shield on the front side of the frame adapted to swing above the upper face of the stoker when the stolrer bar is rocked, a series of grate sections mounted in the frame and normally movable in the operative position, each grate section having a transverse cleft at its rear end, a carrier bar carricd'on the end portions of the frame and extending into said clefts in the grate sections and furnishing support therefor, eachof said grate sections being free to be, removed from and restored to operative position without disturbing the position of the carrier bar, and non-loosing retaining-means normally securing the carrier bar in operative position.

5. In a stoker bar, in combination, a grate portion, and a frame comprising end members each having a recess on its inner face and a lateral extension member forming a horizontal support arranged adjacent the bottom of the correspondin recess and projocting beyond the plane or said inner face of the end member, means for ri idly securing the end members together, and a bar er;- tending at opposite ends into said recesses in the end members and movably bearing upon said. horizontal supports for furnishing support for the grate portion, said bar being free to be lifted from and restored to operative position on the end men'ihers.

6. 111 a Stoker-bar, a frame havingend members each provided on its inner face with a recess and presenting a bar support adiacent the lower extremity of such recess;

a free grate-supporting bar carried on'the end members and arranged to extend at its opposite extremities into said recesses for engagement with said supports; and means ffor preventing lengthwise displacement of the grate supporting bar at one of its ends, including stop means on the bar for engaging one of said bar supports, S8161 bar being supported at its other end for free endwise movement relatively to the corresponding bar support and to the grate. i

7. A stoker bar comprising, in combina tion a grate portion and a grate supporting frame comprising end members each having a recess on its inner face, one of such recesses forming a slot communicating withthe upper edge of the corresponding end member and inclined toward the front side of the bar, a fixed member connecting the end members on one side of the frame and forming a curved shield adapted to swing above theupper face of the stoker when the stolrer bar is rocked, a normally movable free bar supported on the end members and extending at opposite ends into said recesses, said bar having an angularly disposed fixed head at one end free to be inserted into and withdrawn from said slot in one of the end members and providing non-locking retaining means for preventing outward displacement of tl e'bar and grate portion when the stoker bar is rocked.

8. In a rocking stoker bar, in combination, a frame having end plates, each provided with recess on its inner face, one of said recesses being inclined toward the rear side of the frame and con'n'i'iunicating withthe top endge thereof, and a freely removable bar carried on the end plates and extending at opposite ends into said recesses, and-a free grate portion mounted in said frame and receiving support from said bar, said bar and end members being cooperatively adapted to provide non-locking retaining means for preventing outward displacement of the bar and the grate portion when the stoker bar'is rocked.

9' In a device of the class described, in

hers, a grate portion mounted in the frame 7 and comprising a plurality of removable free sections, a free bar carried on the end members of the frame and furnishing support for said grate sections, and means carried on the bar and co-operating with means on the end members of the frame for limiting lengthwise movement of said bar in one direction to prevent adherence of the grate sections to the bar.

10, In a rocking Stoker bar,- in combination, a frame having end members and a men'iber connecting the end members on the front side of the frame and forming a shield, a free carrier bar supported on said end members, a grate portion mounted on said carrier bar and lapping at its front side onto said shield,-said grate portion being free to be removed from and restored to 0p erative position in the frame without disturbing said carrier bar, the mounting for said grate'portion on the carrier bar, including a member extending below the body of the grate portion and having a deep transverse cleft formed therein for freely receiving said carrier lar thereby forming nonlocliing retaining means for said grate portion.

In testimony whereof I name to this specification.

GEORGE H. TEACH-ER, JR.

have signed my

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