US2062477A - Stoker drive - Google Patents

Description

Dec. l, 1936..` w w, PECK v i" 2,062,477 v sToKER DRIVE 3 V` v Filed July 14, 19:54 #sheets-sheet 1 INVENTOR B William WPec/Q- Y ATTORNEYS sToKER Dall-'VE v l Filed July 14, 1934 2 'sheets-sheet 2l 12 l 34 /0` i 'd I JZ F 4 sr 7f3 .14 /J l 5 `l\\\ l 1 3 ff '24 IINVENTOR William WPevk) 1 BY `ATTORNEYS l Patented Dec. 1, 1936 UNITED STATES 2,062,477 ,y s'roxnn Dmvn f wiiiiam w. Peck, Muncie, ma. Application July 14, 1934,7se'riai N6. 135,164 f1 My invention. relates to improvements in mechanically driven furnace stokers, primarily designed for small heating `plants such as are used for heating -dwellings and the like.

More particularly my invention relates to the 1 For the purpose ofv disclosing my invention l have illustrated an vembodiment.thereofin the accompanying drawings in which` l Fig. l is a side elevation, more or less diazo grammatically illustrating a vStoker my invention;

Fig. 2 isan end viewthereof; Fig. 3 is asectional view taken on the line of Fig. 4;

g5' (Fig. 4 is a sectional view taken on the line 4-4ofFig.2;- Y t.

Fig; 5 is a detail of theratchet driving mechanism with means for adjusting its stroke, and

Figs. 6 and 7 are respectively end and side o elevations, partly in section, of a` clutch interposed between the power member and the drive.

In the embodiment of the invention illustrated the stoker mechanism comprises the usual burner I, which is fed through a feed 2 by means of a 35 feed screw from a hopper 3. It will be noted that the hopper is set at an incline so that there will always be a tendency for the coal therein to slide toward the bottom of the hopper and into the feeding screw. By such an inclination the 40 danger of the fuel in the hopper bridging is eliminated. The feeding mechanism is driven from preferably an electric motor 4 through the instrumentality of a transmission 5, a slip clutch 6 being preferably interposed between the motor 45 and the transmission to permit a slip between the motor and the driving mechanism in event the feed mechanism becomes jammed for any reason. 'I'he transmission mechanism is preferably mounted within a casing 1 having a fiat base 8 50 on which it is supported and provided with a removable cover 9. Extending into this casing is a drive shaft I0 which, if desired, may project beyond the two side walls of the casing to provide, at one end, a connection for the driving 55 motor 4 and at the other end a means for driving embodying a suitable blower I I 'lhe shaft I IIy ispreferably mounted in'balLbearings such asvv laarranged inthe walls of the `casing .and ythese liearingsprovide end thrust-bearings as well as side-bearingsfor the shaft. 4 The shaft I6 yis provided with a worm I2 which isgpreferably formed. integrally with the shaft. Extending transverselyrof the shaft I0, which may b'etermed they driving shaft, Y

is a drivenjshaftiaone endfof 'wnicnis adapted tobe connected with ftheffeeding screw I4 of kthe fuel feed. vThis shaft islikewise mountedin ball bearings 'I5 arranged in the side walls ofthe yl"y casing and constituting end as well as side thrust bearings. Rotatably mounted von the shaft I3- is a` worm gear I6 meshing withthe worml 2, and driven thereby. v*The ,hub .of this wormgear I6 is provided with a 'cam member having two cam portions `II and' I8 ,adapted during the rotation `of the gear'l6 'to oscillatethe cam ann,L I`9.,;;This cam arm is mounted onfa transverselyextending shaft and has somewhat .the shape'of a bell crank lever, the extension 2I of whichis provided g y with a pair of pivoted`dogs122'and 2 3... A ratchet wheel 24 is keyed ,on the shaft i3 andthe dogs -o'r pawls 22and 23 are adapte/d tof'engagethe teeth of the'ratchet wheel for rotating thel samein one direction. Due tothe fact that one of the f'dogs,

2s, is' 'slightly ion'gertnan the other. dog'zz, en-

'gagement of thedogs f with the;.teeth of- Vthe ratchet wheelv is insured, even though theos'cillations of the arm 2| may be very slight. A backlash dog 25 rockably mounted on the shaft 20 also engages the teeth of the ratchet wheel to hold the same against backward movement.

For adjusting the throw of the arm I9 I provide an adjustment member comprising a lever arm 26 having a hub 21 surrounding the s'haftx20.

This hub is provided with relatively large key f ways 28 into which take keys 29 on the shaft 20. These keyways in effect form stops for lim'- iting the movement of the shaft'20 and with it the movement of the arm I9this arm being fixed on the shaft 20 which, in itself is rotatably mounted. The lower end of the arm 26 is provided with apin 30 adapted to takeinto spaced apart openings 3l in the side of the casing, and

the arm is maintained with the pin` engaged in a selected opening through the medium of a coiled spring 32 surroundingvthe shaftand abutting,

against a shoulder 33 on rthe hub 21 anda collar 34 on the shaft. It isv apparentthat by shifting the arm 26 to the left, looking at Fig. 2 or Fig. 5,

and raising the arm I6 so that the cam will not engage the same untill it has completed part of its stroke. the length of the stroke of the arm I9 periphery of the rim 3i.

and correspondingly the length of the stroke of the pawls 22 and 23 may be varied to control the rate of feed of the fuel.

In apparatus of this character there is danger` of the screw I4 becoming jammed during the feeding of the fuel, for various reasons, and in order to prevent the stoppage of the motor I by the jamming of the screw and therefore the burning out of the motor, I provide a simplified form of clutch which is preferably interposed between the shaft I0 and the shaft 35 of the motor drive; This clutch preferably comprises a housing member 36'keyed on the shaft I0 and having a rim 31. Keyed on the shaft are a pair of arms 38 operating between the adjacent ends 39 of a pair of shoes 40, which shoes bear onl the inner 'I'hese shoes are preferably maintained in engagement with the rim 31'by coiled springs 4I between the ends ofthe shoes, which springs preferably extend through the-arms 38 without touching the arms. By this arrangement the clutch provides a self-aligning connection between' the motor and the drive mechanism. It is apparent that whenthe arms 38 are rotated they will come in contact with the abutting ends yof the shoes 39 and due to the combined action of the springs and centrifugalA action these shoes will be maintained in frictional engagement with Athe rim 31, whereby friction drive `will be established between the shaft 35 and the shaft I 0.

I have found that'the above construction provides an extremely silent drive, and I have found that this silence is materially assisted by so arranging the arm I9 that during the' return movement of its stroke it does not come in actual contact withv the cams I'Iand i8.

I claim as mv invention; Y

1. In a stoker drive, in combination, a casing, a drive shaft extending into said casing, a worm pinion mounted on said drive shaft, a driven shaft extending into said casing,a worm gear rotatably mounted on said driven shaft, and meshing with said pinion, a cam member operably connected to and rotated by said worm gear, aratchet gear fixed on said driven shaft, an oscillating arm shaft, an oscillatingfarm oscillated by engage ment with said cam member, a stop member on said oscillating arm shaft and a second stop member on said cam arm to limit the return movement of said cam arm, means for adjustably rotating said oscillating arm shaft to adjust the relative positions of said stops and pawls pivoted on said oscillating arm and adapted to engage the ratchet teeth on said `ratchetgear during the positive movement of said arm under the action of said cam.

2. In a stoker drive, in combination, a casing. a drive shaft extending into said casing, a worm pinion mounted on said drive shaft, a driven shaft extending into saidvcasing, a worm gear rotatably mounted on said driven shaft, meshing with said pinion, a cam member operably connected to and rotated by said worm gear, a bell cranklever shaft, a bell crank loosely mounted on said shaft, one of the arms ofsaid bell crank to be biased into engagement with said cam member and the other arm having pawls pivoted thereon for engagement with the ratchet teeth of said ratchet gear, a key on said bell crank lever shaft, and a key Way in the hub of said bell crank lever shaft of greater width than said key, and means for rotatably adjusting said bell crank lever shaft.

3. In a stoker drive, in combination, a drive shaft, a driven shaft, constant mesh reduction gear membersone fixed to said drive shaft, a cam member xed relative to the .other and slower speed reduction gear member, a one-.way intermittent drive assembly including a driven part fixed to said driven shaft'and a drive part,` an oscillatable arm shaft, an arm carried on said` arm shaft and mounted for limited rotation relative thereto, said drive partbeing mounted on said arm and voperatively engageable' with said driven part, said arm being adapted to engage -with said cam member, a stop member on said oscillating arm shaft, and a second stop member on said cam-engaging arm to limit the return` WILLIAM W. PECK. e

Images