US1804638A - Actuating means for fuel agitators - Google Patents

Description

May 12, 1931. D. .J.. MQSSHART ACTUATING MEANS FOR FUEL AGITATORS Filed May 22, ,1925 2 Sheets-Sheet l All/54w :0

llMoaahart INVENTOR BY ATTORNEY May 12, 1931. D. .J. Qno'ssHAR-r 1,804,638

ACTUATIflG MEANS FOR FUEL AGIIATORS Filed May 22. 1925 2 Sheets-Sheet 2 N 9.1 Massharf INVENTOR BY 496 M ATTORNEY Patented May 12, 1931 UNITED STATES noivn'tn J. MOSSHART, OF PHILADELPHIA,

& MANUFACTURING scrimmage CORPORATION or PENNSYL- HOUSE ELECTRIC I VANIA PATENT OFFICE PENNSYLVANIA, ASSIGNOR T TESTING ACTUATING MEANS FOR FUEL AGITATORS I Application filed May 22,

I and which shall be extremely flexible in operation, permitting any desired control of the agitating effect within prescribed limits.

In the accompanying drawings, Fig. 1 is a side view, partially in section and partially in elevation, of an automatic stoker of the underfeed type illustrating the application of my invention thereto; and Fig. 2 is a perspective View showing my invention more in detail. I

In the operationof automatic stokers, particularly of the large size underfeed type, it frequently happens" that the fuel bed at the rear of the stoker is of such thickness and of such dense formation that it is diflicult to pass suflicient air thereto to burn out the combustible. It has been proposed therefore to provide an agitating means at the rear of such furnaces in order to breakup these dense fuel masses. 7 1 v 1 It has been found undesirable to operate such agitators continuously as combustion is interfered with,and accordingly it is desir-' ableto operatethese agitating means only -for a short period at a 'time, permittingthe fuel bed to assume a more or less quiescent state between periodsof operation.

cylinder, and the valve gear of said cylinder is operated as from the main ram drive through the intermed ary of a pawl mechanism whereby the valve mechanism isoperated for predetermined intermittent periods, the frequency of such periods being under the 1 control of the operator.

Referring to the drawing for a more detailed understandingof my invent on, I show 1925. Serial No. 32,103.

the main grate portion of a stoker of the underfeed multi-retort type at 10 in Fig. 1,.fuel being introduced thereto through a front wall 11 as by aram 12, all as is well-known and understood in the art.

Thefuel agitatoris disposed behind the main grate surface 10 and may take, for example, the form shown in U. S. application Serial No. 643,368, filedJune 4c, 1923, by the Vestinghouse Elec. & Manufacturing Company on an inventionof Otto Aram. Briefly speaking, a tilt'able member 13 has a rock- 111gv member 14: overlying the front end thereof, said members preferably being perforated for the-admission of air to the fuel lying thereon. The member 13 may be rocked as by an arm 15 and a link 16, such rocking also causing a rocking motion of the member 14.

The link 16 is connected to the piston 17 of a steam cylinder 18' and steam may be admitted thereto by any'desired means such, for example,'as'a dumbbell valve 19 having an operating stem 20.

Referring more particularly to Fig. 2, the operating stem 20 carries a lug 21 disposed 1n proximity to anotched disc 22 mounted on a shaft 23 -23, said shaft also carrying a toothed disc 24.

A bridlemember 25 is pivoted on the shaft 23 and carries a main pawl 26 and a secondary pawl 27. The main pawl 26 rides upon the periphery of the disc 22 but is somewhat wider than thethickness of said disc so that this pawl overlies the lug 21 on the valve stem 20. The arrangement is such that if the pawl operating bridle be oscillated with the pawl 26 in a notch of the disc 22, it may engage with the dog 21 on each forward stroke, resulting in a reciprocation of the valve 19. If, however, on the other hand,

the pawl 26 is riding on a-tooth of the disc 22 between two notches, it is restrained out of contact from the dog 21 and oscillation thereof does not affect the valve 19.

The secondary pawl 27 bears on the periphery of the disc 24 so that oscillation of she bridle 25 causes said'pawl to rotate said we r A pawl guard 28 is provided to control the action of the pawl 27 upon the disc 24, said )awl 'uard bein carried b a )ivoted arm 29 operable as from the front of the seeker by a link 30. When the pawl guard 28 is in the position shown, the pawl 27 rests on the disc 24; at all times and forward move ment of the pawl 27 produces a maximum rotation of the disc 2a. When, however, the pawl guard 28 isrot-ated; on the member 29 in a clockwise direction, it passes into the path of travel of the pawl 27, raising said pawl on the back strokeand; permitting it to engage teeth only during the latter part of its forward stroke, thuseii ectu'ally controlling the rate of rotation of the disc 24 and accordingly ofthe disc 22; 7

The bridle 25 is connected for oscillation to themain ra n 12 as through an arm 81-and link 32 Having thus described the structure of apparatus embodying a preferredform of my invention,tli.e operation thereof is as follows Assuming the stoker to be in operation anda relatively thick fuel bed to overlie the members 1 3 and 114:, reciprocationof the ram 12 causes slowjrotation of the disc through the pawl- 27 l with attendant revolution of the disc 22. The pawl 26 rides 'l'reelyifor considerable period of; time" because" resting on top of atooth oi the disc 22 and accordingly not engaging the dog -21. After a predetermined period, however, a notch ofthedisc 22 comes under the pawl 26, permitting said pawl to drop and to the dog 21, actuating the valve mechanism, said'valve mechanism being returned after action, as by a spring'3'3: Thus the agitators '13 and '14 will he violently rocked for example, two or threetimes and wi lri'then remain at rest-for a considerable period oi time before again being rocked. 'Llhus the fuel bed is maintained in a bro n up condition and effective combustion is'mai'ntained by .the passage of air through theresultant cracks.

By l iri nging the pawl guard- 28 into play,

the attendant may materially slow dowi'i the F 2 a gular velocity oi"- the disc 2%, sulting in longer periods oi rest between successive periods of action ot the fuel agitators.

Itv will be obvious that my invention i'uay bemodified in various respects without tie-- parting from the spirit thereofi Thus, for example, the pawl 26 might be, caused to en gage the dog 21 when riding on a toothand to disengage therewith when riding in a notch, but I consider all such modifications to be obvious in view of the foregoing description and; accordingly I desirethat no limitations-shall be placed upon the scope of my invention except such as are'set forth herein and'inore particularly in the appended claims. I

lVhile I have shown my invention in but one form, it willbe obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modilications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placedthereupon as are imposed by the prior art oras are specifically set forth in th'e'appended claims.

lVhat I claim is 1;. The combinationwith, progressive. feed Stoker including a fuel agitating. grate section in the fuel supporting surfacelth'ereoii, of a pressure operated piston for actuating the grate section, a valve member for controlling the piston and having'a valve stem carrying a lug, a notched disc, a pawl member riding on the periphery of said disc, said pawl member being arranged. to effect a driving engagement with said lug on the valve stem when riding ina notch of said disc, means for oscillating saidpawl member, means for slowly rotating said disc, and means for retracting said valve member after the latter has been urged forward by the engagement of said pawl member with said dog; a

2. The combination with a progressive feed stoker including a fuel feeding mechanism anda fuel agitating grate section in the fuel supporting surface thereof, of a pressure operated piston for actuating the grate section, a valve member for controlling the piston, 'a stem for said valve, member provided with a step portion, a pawl adjaccnt to. said step portion, an operative connection between'the 'fuel feeding mechanism and. the pawl for imparting a to-andiro motion to said pawl, the pawl adapted to havea driving engagement with the step portion upon a movement in one directiomineans for periodicallyaltering'the path of travel of the 'point of 'saidpa'wl from acondition of engagement to a condition of nonengagement with'respect to said step portion and viceversa, and means for retracting said valve stem aft-er movement by said pawl.

3. The combination with a progressive feed stoker including a fuel agitating grate section in the fuel supporting surface thereof, of-a pressure operated piston for-actuating the grate section, a valve member for controlling the piston, a valve stem for the valve member and having a lugprovidedthereon, a disc having notches in the periphery thereof,fa main pawl of greater widththan the thickness ofsaid disc'riding on the periphery of said disc in proximity to said lug-the arrangement being such that said main pawl may operatively engage SitlCllLlfZ- when riding inthe bottom of a notch and beraised fmm an 'engaging'position when riding between notches, a tootheddiscmounted on the shaft of said notched disc, a secondar.y pawl riding on the periphery of 'thetoothed-disc, a bridle member. mounted for oscillation on said shaft and carrying. said two pawls,

means for oscillating said bridle member, a pawl guard for determining the arc of en gagement of said secondary pawl with its associated disc during eachoscillation, and means for retracting said valve stem after actuationby said main pawl.

l. The combination with an automatic stoker including fuel-feeding means, and a projection when resting in a notch and being.

raised out of engagement when riding between notches, a toothed disc mounted on the shaft of said notched disc, a secondary pawl riding on the periphery of said toothed disc, an oscillatable bridle member carrying said pawls, means for oscillating said bridle mem her from the fuel-feeding means, a pawl guard for determining the arc of engagement of said secondary pawl with the associated disc during each oscillation, and means for retracting said valve stem after it has been actuated by said pawl.

5. In a furnace, the combination with an automatic stoker including a fuel-feeding means and a fuel agitating grate section forming a part of the fuel supporting surface, of means for actuating the grate section, mechanism operated in timed relation to the operation of the fuel-feeding means for controlling the operation of the grate actuating means in such a manner that the grate section is agitated intermittently for predetermined periods of time, and means providing for an adjustment of the controlling mechanism so as to vary the length of time between and the duration of the operating periods of the grate section.

6. In a furnace, the combination with an automatic stoker including fuel feeding means and a fuel agitating grate section forming a part of the fuel supporting surface thereof, of mechanism operating in response to the operation of the fuel feeding-means for intermittently operating said agitating grate section for predetermined periods/of time.

7 In a furnace, the combination with an automatic stoker including fuel feeding means and a fuel agitating grate section in the fuel supporting surface thereof, of a fluid pressure cylinder and piston for actuating said grate section, valve means for controlling the operation of said piston, a mechanism operatingv in response to the op eration of the fuel feeding means for intermittent ly actuating said valve means for predetermined periods of time.

8. The combinationwith a progressive feed stoker including a fuel agitating grate section in the fuel-supporting surface thereof,

of a pressure-operated piston for actuating the grate section, a valve member for controlling the piston and having an actuating stem provided with a lateral step portion, a pawl V mounted for to and fro motion and adapted,

when moved in one direction, to have a dI'IV ing engagement wlth the lateral step port-ion, means for efiecting such motion of the pawl,

'means providing for periodical engagement of. said pawl and said step portion for predetermined periods, and means for retracting said valve stem after movement by said pawl.

9. The combination with a progressive feed stoker including a fuel agitating grate section in the fuel-supporting surface thereof, of a pressure-operated piston for actuatout of engagement'with the face when riding between notches, means for oscillating said pawl, means for slowly turning said disc, and means for retracting said valve stem after actuation by said pawl.

In testimony whereof, I have hereunto subscribed my name this eleventh day of May, 1925.

DONALD J. MOSSHART.

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