US1975489A - Driving mechanism for stokers - Google Patents

Description

J. VAN BRUNT 1,975,489

DRIVING MECHANISM FOR STOKERS Oct. 2, 1934.

Filed DeG. 2, 1931 5 Sheets-Sheet l BY y Z i 56 .ATTORNEYS INVENTOR J. VAN BRUNT DRIVING MECHANISM FOR STOKERS Flled Deo Oct. 2, 1934.

oct. 2, 1934.

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Oct. 2, 1934. J. VAN BRUNT DRIVING MECHANISM FOR STOKERS Filed Deo. V2. 19:51 5 sheets-sheet s INVENTOR Y 16W M Patented Get. 2, 1934 PATENT OFFICE-Y DRIVING. MEcHANisM Fon s'roKERs John. Van Brunt, Flushing, N. Y assignor toV International Combustion Engineering Corpo,-`

Vration, New York, N. Y., a corporationof Delav ware- Application December 2, 1981, serial No. 578,518 9 claims. (c1. 'x1-26) This invention relates to driving mechanisms for stokers.

`One of the primary objects of my linvention is the provision of a drive for stokers of a character suchf that an inexpensive motor may be employed.

More particularly it is an object of my invention to provide a simple vand effective way by which the stroke of thereciprocating portions of 'I0 a Stoker maybe varied' at will to suit varying How the foregoing-,together with such othery objects andadvantages as may hereinafter appear or are incident to my invention are realized, is'

illustrated in preferred form in the accompanying drawings, wherein: 'y

Figure 1 is inA part a side elevational view and inA part a sectional elevational view showing a Stoker constructed inA accordance with myl inventien applied to a furnace, the lower portion of which is illustrated in section;

Figure 2' is a crosssection taken in substantial part on the line 2-2 of Figure 1, but with the right-hand grate and associated tuyre construc- '3 tion shown in section taken on the line 2a-2a of Figure 1;

Figure 3 is an enlarged longitudinal section of the left-hand portion of Figure 1;

Figure 4 is a plan view of the left-hand portion of Figure 1;

Figure 5is an enlarged front view of a selector and controllingv device'which I employ, with the upper portion of the casing structure in section to more clearly show certain of the interior parts;

Figure 6 is a side View ofFigure 5, with the upper portion of the casing structure in section;l

Figure 7 is a planview of Figure 5, with the cover removed, and Y.

Figures 8 and 9 are detail views illustrating a cam assembly Vwhich I employ.

retort, underfeed, .lateral overfeed type and comey prises iny general a coal hopper A, a feeder box B,

a feeding device indicated asa whole by thereference letter C, a retort D, a wind box- E, tuyres F at each side of the retort, and side grates Gbelow which an ashpit is located. The Stoker mayl be applied. to various types of furnaces, such as the V furnace H illustrated in Figure .1.' Air is led to:

the wind box E from a fan E by means of a duct E. 1

The feeder device C comprises a 'reciprocating plate or sliding bottom 9 having a pusher blocky or ram 10 mounted thereon at the hopperV end 601 (see Fig. 3) and auxiliary pushers orrams 1-1 and 12 located at intervals therealong. When the feeder device is reciprocated, coal is fed from the hopper A through the feeder box B and into the retort D by means of the pusher block 10, which, k with each forward movement of the bottom 9, pushes a charge of coal into the retort. Theauxa iliary pushers aid in the distribution of the'fuel` from the front to the rear of the retort.- 'Ihe amount of coal fed to the retort depends .upon 70.` the reciprocations. of the sliding bottom, and the mechanism which I employ to vary the feed will be described fully hereinafter.

In operation, the coal remains in the retort for a period of time during which it passes through 'Z5v a coking process and as it.nears the top of the nre Yit becomes incandescent. At this point the tuyres admit a forced blast of air from the wind box to burn the yfuel'. Combustion `of any unburned fuel is completed onthe adjoining side grates G which are provided with shakingmecha'- nism as indicated at 13 in Figure 2.

lThe feeder device C isadapted to be recipro-l cated by means of driving mechanism indicated as a whole by the reference' letter J and compris- 85' ing in general a constant speed motor 14, a reciprocating driving member or operating block 15 adapted to be reciprocated with constantllength and speed of stroke, by means of a crank shaft 16 to which it is connected by a connecting rod 17, the operating block 15 being suitably guided in slots 18 provided in the side Walls of the feeder boxstructure B.V

Gear reduction mechanism K is located between the motor Vand the crank shaftand'comprises in 95V general reduction gearing 19 of any conventional type, having a driving shaft 20 adapted to receive its drive from the rmotor by means of a chain drive 21 and having its final driven gear 22 mounted on the crank shaft 16. Thus the 103 t t The particular Stoker illustrated is of the single constan Speed m0 or 14 drlves the Crank Shaft at reduced speed andthe crank shaft imparts continuous reciprocatory movement to the operating block or driving member 15.v It is pointed out, however, that the driving member 15 is not 105 in driving connection with the sliding'bottorrrQ at all times, for I have provided mechanism which is adapted to establish driving connection between the driving mechanism and the feeding device onlyat vpredetermined intervals and, therefore,

the driving member 15 runs at times in idle stroke.

The mechanism referred to includes a latch device 23 having a movable latch member or pawl 24 pivotally carried by the sliding bottom 9 by means of a rock pin 25 and a fixed latch member 26 carried by the operating block or driving member 15; and a selector and controlling device indicated as a whole by the reference letter L adapted to actuate the latch device.

Before describing the device L in detail, it is pointed out that when the latch device is in its latching position, as illustrated in Figure 3, the latch member 24 hooks over the latch member 26, thus connecting the driving member 15 to the sliding bottom 9. The device L is so timed andV the latch device so located that it is actuated to its latching position when. the crank arm of the crank 19 and the driving member 15 are in their eXtreme forward positions, so that as the crank continues to rotate, the sliding bottom is pulled in its back or outward stroke by virtue of the latch connection. In order to prevent unlatching of the latch device in this movement, I have inclined the latch engaging surfaces so as to obtain a wedge action.

It will thus be seen that the device L which controls the latch device need only hold the latch member 24 in its downward position for a very short time, because the latch member cannot disengage while the crank is pulling the driving member to the left, i. e., in its outward or backward stroke. As soon as the driving member 15 begins its inward or forward stroke, the latch member 24 is raised out of contact with they latch member 26 as by means of a counterweighted lever 27 secured to the rock pin 25. The member 24 will remain in its unlatched position until it is again moved to its latching position by the device L. On the inward stroke, the driving member 15 also moves the sliding bottom 9 inwardly, contact being made between an abutment 28 on the sliding bottom and the end surface 29 of the member 15, although on this inward strokethe driving device is not connected to the feeding device other than by abutment contact. Therefore, with the latch device in unlatched positon, the driving member 15 is free to reciprocate back and forth in idle stroke until the latch device is next moved into its latching position.

Theselector and controlling device L above referred to comprises in general a casing 30 having bearings 31 for a cam shaft 32, a plurality of cams 33 secured on the cam shaft 32, and a lever 34 adapted to be actuated by the cams. The lever 34 is pivoted in the casing at 35 and carries a roller rod 36 at its inner end and a projecting arm 37 at its outer end. A cam roller 38 is slidingly and rotatably mounted on the rod 36. The cam roller 38 is adapted tobe moved lengthwise of the rod by means of a forked shifter member 39 which is slidingly mounted on a rod 40 supported by the casing 30 in parallel spaced relation to the roller rod 36.

In this instance I have illustrated nine cams 33 as being mounted on the cam shaft 32 to rotate therewith and the iirst cam a starting from the left of Figures 5 and 8 is blank, i. e., the cam surfaceV thereof with which the cam roller 38 is adapted to contact is concentric with the axis of the cam shaft. The second cam b is provided with one cam lobe or tooth b', the third cam c with two cam lobesc, the fourth cam d with three cam lobes d', and so on up to the ninth cam i, which is provided with eight cam lobes i.

The cam roller 38 with its shifter member 39 is adapted to be moved in a direction longitudinally of the casing by means of a Sluiter arm 41 secured on a rock shaft 42 at its lower end, and having a forked upper end 43 adapted to straddle a pin 44 carried by the shifter member. The shaft 42 is mounted to rock in a bearing 45 at the lower portion of the casing 30 and has secured to its outer end an arm or shifter lever 46.

The shifter lever 46 and shifter arm 41 are adapted, when actuated, to move the cam roller 38 into registry with any one of the plurality of selector cams provided on the cam shaft. In Figure 5 the shifter mechanism is shown in a positionsuch that the cam roller 38 engages the blank cam a and therefore, when the cam rotates, no movement is imparted to the lever 34. An arcuate pad 47 is provided on the side of the casing at which the shifter lever 46 is mounted and is provided with a plurality of holes 48 corresponding in ninnber and spacing to the numbei` of cams employed. An upwardly projecting arm 49 is provided on the shifter lever 46 which arm carries a pin 50 adapted to be inserted in a hole 48 corresponding to the particular cam selected for operation. This pin not only holds the shifter mechanism against unintended displacement, but also gives an indication as to which cam has been selected for operation. The

pin may bel attached to the arm 49 as by means of a chain 51, such as illustrated in Figures 5 and 6, to prevent its being lost.

. In the event that automatic control is desired, the shifter lever 46 may be automatically operated by connecting it to any suitable form of automatic regulating device as by means of a cable 46a. In such instances, the pin 50 would be removed and a counterweight 46h would be y applied to thelever 46.

The cams are rotated by means of a sprocket n wheel 52 secured on the cam shaft 32 and receiving its drive from the crank shaft 16 through the medium of agear 53 secured on the crank shaft, a gear 54 meshing therewith, a sprocket wheel 55 mounted on the shaft of the gear 54 and a chain 56 drivingly connecting the sprockets 55 and 52. It will thus be seen that since the motor 14 drives the crank shaft at constant speed, the selector cams 33 will also be driven at constant speed. The speed ratio in this instance is such that the cam shaft 32 rotates at oneeighth of the speed of the crank shaft, although it is to be understood that the speed change as between the crank shaft and the cam shaft is determined by the number of cams and cam lobes employed in the selector mechanism.

A plunger 57 is mounted in a support 58 secured to theV side of the feeder box structure in such location with respect to the selector and controlling device L that the under surface of the arm 37 of the cam operated lever 34 engages the upper rounded end of the plunger. The plunger is maintained in engagement with the arm 37 by means of a spring 59 and a roller 60 is carried at the lower end of the plunger. The roller 60 contacts with an arm 61 of the counterweighted lever 27 above referred to, and when the plunger is depressed the arm 61 is moved downwardly so as to rock the rock shaft 25 in a direction to cause engagement of the'latch member 24 with the latch member 23. The plunger is moved into its depressed position when the lever 34 is actuated by a cam lobe and is spring returned to its non-depressed position Vfrom the same motor.

when the'cam roller 38 leaves a cam lobe, and rides on the concentric Vportion of thev cams. When theA plunger moves to its non-depressed position, the rock shaft' 25 is free to rockin adirection to cause latch disengagement'under influence of the weighted lever 27, although fas above pointed out, such latch 'disengagement does not take place until the driving member 15 has reached the ,end of its outward stroke and starts on its inward or forward stroke. In Figure l the parts just described are illustrated in the position they assume when the latch mechanism is being actuated by a cam lobe of one of the cams of the selector device L.

The cams 3,3 are so timed that latch engagement takes place at the end of an inward or forward stroke of the operating member 15, and therefore, when the shifter mechanism of the selector device is moved to its position for selecting the cam b, for example, the latch will be moved to latching position when the single cam lobe b of the cam operates on the lever 34 to actuate the plunger 57. As soon as the cam lobe has passed the cam roller, the plunger returns to its non-depressed position and remains in such position until the cam lobe again actuates the lever 34, such actuation taking place once in eight back and forth reciprocations ofthe driving member 15. 'Ihe operation is similar for the cam c, except that the lobe is moved to latching position twice in eight complete back and forth reciprocations of the driving member 15 and so on for all of the cams up to the last cam i which actuates the latch device once for eacn complete back and forth reciprocation of the driving member.

In the particular arrangement disclosed, speed variations from one to one to eight to one may be obtained, although it is to be understood that with additional cams and suitable change of ratio between the cam shaft and the crank shaft, greater variation may be obtained.

It will be seen from the foregoing that I have provided a driving mechanism for stokers by which the stroke of the reciprocating portions of a Stoker, such for example as a reciprocating feeder device, may be carried at will to suit variable operating conditions while employing an inexpensive constant Speed driving motor, for I am enabled through the use of the selector and controlling mechanism to cause the reciprocating feeder to feed coal intermittently at predetermined and variable intervals, according to the selection made, even though the mechanism for driving the feeder be running continuously. While I thus vary the coal feed, the length and speed of the feed stroke is nevertheless constant so that proper fuel bed conditions are insured at all loads. The arrangement is also such that a single driving motor operates the feeder device, the selector and controlling device, and the fan E'. Furthermore, the arrangement permits of supplying air to the Stoker without feeding coal even though the fan and feeder device are driven The device is simple in design, of rugged construction, and requires minimum aisle space.

1. A driving device comprising a reciprocating driving member, a driven member adapted for reciprocation, and selectively controllable means for rendering idle certain of the strokes of the driving member, for connecting the driving member to the driven member so as to render the re- Y maining strokes driving, and for connecting said members so as to render all of Vthestrokes driving.

2; A driving device comprising areciprocating driving member, a-driven member adapted for reciprocation, means for 1 releasably connecting said members togetherjand selective mechanism for actuating said means to connect saidmembers for reciprocationv together in every reciprocation of the driving memberv or to connect .said members in only 'certain reciprocations of a cycle and-t0 disconnect the'members in theremaining reciprocations ofthe cycle. f

3. A driving device comprising a reciprocating driving member having a set stroke, a driven member adapted for reciprocation, means for releasably connecting said members for reciprocaton together in said set stroke, and selective mechanism having a selector member for effecting such connection for certain of the strokes of the driving member, and a selector member for effecting such connection for every stroke of the driving member.

4. A driving device comprising a constant speed reciprocating driving member, a driven member adapted for reciprocation, means for releasably connecting said driving member to said drivenmember, actuating means for said connecting means, and a selector device operatively associated with said actuating means for governing the actuation of the connecting means including a plurality of movable members, means for moving said members, and selector members carried by said movable members for controlling the operation of the actuating means, one of said selector members being adapted to effect control whereby the driving member is connected to the driven member in all of its strokes.

5. A driving device comprising a driving member adapted to run in driving and idle strokes, a driven member adapted to be variably driven by said driving member, a plurality of cam members with varying cam surfaces, means actuated by said cam members for controlling said strokes, and means for selecting any one of said cam members to actuate said means, one of said cam members having cam surfaces'arranged to render all of the strokes of the driving member driving.

6. A driving device comprising a constant speed motor, a driving member driven by said motor at constant speed, a driven member, means for connecting and disconnecting said driving and driven members, an actuating member for said means, a plurality of cams the cam surfaces of which differ from each other, means for driving said cams at constant speed, and means for moving said actuating member into position for operation by any one of said cams.

7. A driving device comprising a constant speed driving motor, a reciprocable driving member, a reciprocable driven member, means for imparting reciprocating movement to said driving member from said motor, normally unlatched latch means associated with the driving and driven members, means for latching said latch means to connect said driving and driven members for reciprdcation together in the same length of stroke, including an actuating member and selective cams controlling the actuating member.

8. A driving device comprising a constant speed driving motor, a reciprocable driving member, a reciprocable driven member, means for imparting reciprocating movement to said driving member from said motor, normally unlatched latch means associated with the driving and driven members, means for latching saidv latch, means to connect said driving and driven mem- CII ing reciprocatory movement to the driving mem= ber from said motor, latch means for connecting said driven member to and -or disconnecting it from said driven member, a plurality of rotatable Cams with Varying number of cam lobes, means for driving said cams at constant speed, and means for actuating said latch means including a member shiftable into operative relation with any one of said cams.

JOHN VAN BRUNT.

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