US1297116A - Furnace-grate. - Google Patents

Description

W. M. DUNCAN.

FURNACE GRATE. A-PPLlcATioN FILED Diano. ma.

Patented Mar. l1, 12H9.

2 SHEETS-SHEET Y [A 'VENTUR l lll ms nomas uns w Haw-uma, wnswmcmu. n. c.

W. M. DUNCAN. FURN'ACE GRATE.

AFPLHAHON4 FI'LED 1150.10, 1918. 1529731 16. Patented Mm. 11,1919.

2 SHEETS-SHEET 2.

5 Eiga- WILLIAM M; DUNCAN', OF ALTON, ILLINOIS.

FURNACE-GRATE.

Specification ofLetters'Paten- A Patented llIlI'. 11, 1,919'. y

Application filed Decemberv 10, 1.91'8. Seria1No..266,120.

To all whom t may concern.'

Be it known that I, WILLMM'M. DUNQAN, a citizen of the United States of Amerlca,

a resident of Alton, in the county of Madison, Statey of Illinois, have invented certain new and usefulf Improvements in Furnace- Grates, of which the following is a full, clear, and exact description, reference. be,- ing had to the, accompanying drawings, forming a part of this specification.

This invention relates to improvements in furnace gratos, and more particularly to a chain grate adapted to form part ofV a mechanical stoker. Grrates` of this kind usually consist ofendless rows of gratelinks and pivot rods extending throughl the several rows to form pivotal connections for the links.

The endless rows of grate links travel slowly to receive thefuel near one end` of the grate structure,l and to discharge the ashes at the other end. Sprocket wheels arcor-dr narily used to. transmit power tothe endless rows of grate links, the links being pulled in an. endless course, and the pulling stresses being transmitted through the pivots whereby the links are connected. Each grate link is usually provided with two pivot-receiving openings, and if all the links are made exactly Valike the pulling stresses would be uniformly distributed throughout the several rows ofgrate links.

However, in actual practice, the links are usually iron castings, and owing to inaccuracies in the castings the links are not exact duplicates of each other. The distance between the pivot-receiving openings will vary, and some of these openings may be larger than others. Prior to this invention, the rows of inaccurately formed links have been connected together by means of rigid pivot rods, sponse to the pulling action of the links. As a consequence, the pulling stresses have not been uniformly distributed throughout the grate. Some of the links are severely tensioned by the pulling stresses, while others are free of tension, and some portions of they rigid pivot rods are subjected to very severe bending or shearing stresses, while other portions of the rigid rods merely support the loose links. Y

The main object of the present invention is to uniformly distribute the pulling stresses throughout the grate, thereby avoiding undue stresses to which the inaccurately which do not yield in reformed structure is ordinarily subjected. Instead of using rigid-pivot rods, the several rows of grate links are flexibly connected together, preferably by means of iiexible pivot members adapted toy yield so as to compensate for inaccuracies in the grate structure. When the rows of grate linksA are pulled and placed under tension, the flexible vpivot ymembers will bend and automatically adjust themselves to receive the` stresses transmitted through all of the endless rows of grate links.. Each link will then firmly engage two of the flexible pivot members, and the pulling stresses will ber transmitted throughout all of the endless rows of links and more uniformly distributed through all of the links and pivots.

I/Vhen the grate is in4 service, the endless Vchains travel around wheels at the ends of the structure, and to permit such movements the links should turn freely on the pivot members. Ashes, line particles of fuel, and other matter drop onto the pivot members, and the pivots are subjected to high temperatures. In actual practice, I have found that severe strains resulting in breakage are sometimes caused by the failure of the ordinary pivot rods to provide free pivotal connections. In accordance with the present invention, the grate links may be pivotally connected together by means of spiral formed flexible pivot members, preferably wire rope members. These twisted, spirally formed 'members exert a crushing or grinding action on the material which passes into the pivot-receiving openings, and acting like screw conveyers, they tend to feed or deflect the fine material from the openings. Therefore, spirally formed pivot members always form the desired loose, free pivotal connections for the links.

Figure I is a side elevation, partly in section, of a mechanical stoker provided with a grate constructed in accordance with the present invention.

Fig. II is an enlarged transverse section on the line II-IL Fig. I, showing the upper portion of the chain grate.

Fig. III is a fragmentary section drawn to a very large scale, and showing one of the spirally formed pivot members mounted in a grate link.

To illustrate the invention I have shown a mechanical stoker comprising an endless chain grate supported by a large, portable frame, said frame including side frame members l mounted on wheels 2, rods 3 eonnecting the side frame members, and rollers a mounted on the rods 3.

T he endless chain grate comprises several endless rows of grate links 5 connected by means of pivot members A arranged transversely of the grate. A power shaft 7, mounted in the side frame members l, is provided with sprocket wheels S for transmitting movement to the endless grate, each grate link 5 (Figs. Il and lll) being provided with circular bosses 5 adapt-ed to-y reeeive the sprocket teeth. The chain grate is mounted on the sprocket wheels 8, and also on a plain idle wheel or roller 9, the latter being mounted on a shaft l0. The fuel passes from a. hopper l2 to the top face of the grate, and the grate links travel over the rollers 4.

Each grate link 5 is preferably provided with two pivot-receiving openings, and the flexible pivot-s A, preferably sections of wire rope, pass through said openings to pivotally connect the grate links in each of the endless rows. Each wire rope member consists of a number of relatively small wires twisted to form several spirals which extend longitudinally of the rope. These spirally formed pivot members form a desirable flexible Connection for the endless rows of grate links, and they permit the links to turn freely in passing around the wheels 8 and 9.

The ends of the pivot members project from the side faces of the grate structure, as shown in Fig. ll. Retaining members, in the form of split collars 12, are preferably clamped onto the projecting ends of the pivot members, so as to retain the latter in the pivot-reeeiving openings. rlChe split col- Copies of this patent may be obtained for ve cents each,

lars l2 may be secured by means of clamping bolts 13, which pass through extended portions of the collars as shown in Figs. Il and Hl.

I claim:

l. A ehain grate comprising rows of grate links having pivot-receiving openings, and flexible pivot members passing through said openings and pivotally connecting the grate links.

2. In a chain grate, rows of grate links having pivot-receiving openings, and flexible pivots comprising wire rope members arranged transversely of the rows of grate links and passing through said openings to pivotally connect the grate links.

3. ln a chain grate, endless rows of grate links having pivot-receiving openings, spirally formed pivots Comprising wire rope members arranged transversely of the rows of grate links and passing through said openings to pivotally connect the grate links in each of said endless rows, and retaining members secured to the ends of said wire rope members to retain said rope members in said openings.

fl. ln a chain grate, endless rows of grate links having pivot-receiving openings, spirally formed flexible pivots comprising wire rope members arranged transversely of the rows of grate links and passing through said openings to pivotally connect the grate links in each of said endless rows, and split collars clamped onto the ends of said wire rope members to retain said rope members in said openings.

In testimony that l claim the foregoing l hereunto aftix my signature.

VILLIM M. DUNCAN.

by addressing the Commissioner of Patents,

Washington, 33. C.

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