US2333316A - Automatic coal stoker - Google Patents

Description

1943- R. KLOSSNER AUTOMATIC COAL STQKER Filed 001;. 9, 1939 3 Sheets-Sheet 1 INVENTCR 3056 212 [X08522 e2 BY 1/ ATTORNEY R. KLOSSNER AUTOMATIC COAL STOKER Nov. 2, 1943.

3 Sheets-Sheet 3 INVENTOR Filed 001;. 9, 1939 ATTORNEY Patented Nov. 2, 1943 UNITED STATES EPATENT OFFICE AUTOMATIC COAL STOKER Robert Klossner, Alliance, Ohio Application October 9, 1939, Serial No. 298,702

2 Claims.

This invention relates to improvements in automatic coal stokers especially designed for household furnace use, and particularly to stokers of that type embodying a feed screw intermittently operated at a low rate of speed from an electric motor, or other relatively high speed motor, continuously driven in one direction at a constant speed.

One object of the invention is to provide a stoker mechanism which may be easily regulated as to feed speed, which is simple in construction and composed of parts not liable to easily get out of order, which may be manufactured and sold and kept in working order at a comparatively low cost, and which allows easy and inexpensive replacement of those parts most subject to wear when occasion requires.

A further object of the invention is to provide a novel, reliable and efficient type of hydraulically operated transmission mechanism for actuating the feed screw from the electric motor or prime mover.

A still further object of the invention is to provide a transmission mechanism of the type described which is wholly or largely self-lubricating, and to provide a sectional construction of feed screw and other parts most liable to wear whereby these parts when worn may be replaced in an easy, convenient and inexpensive manner.

With these and other objects in view, the invention consists of the features of construction, combination and arrangement of parts, hereinafter fully described and claimed, reference being had to the accompanying drawings, in which:

Fig. l is a perspective view of an automatic stoker embodying my invention shown in connection with a furnace, with parts broken away and in section.

Fig. 2 is a vertical transverse section through the stoker casing showing parts of the stoker mechanism in end elevation.

Fig. 3 is a perspective view of parts of the stoker mechanism disassociated from the casing.

Fig. 4 is a perspective View of the valve block per se.

Fig. 5 is a sectional plan view on an enlarged scale through the hydraulic motor.

Fig. 6 is a view of the distributor valve.

Fig. '7 is a view of the reversing valve.

Fig. 8 is a perspective View of one of the sections of the feed screw showing the construction thereof.

Fig. 9 is a sectional view through the pressure speed regulator.

Fig. 10 is a view showing a modification.

Fig. 11 is a vertical section on line ll-ll of Fig. 4.

Figs. 12 and 13 are detail vertical sections through the opposite ends of the pilot valve chamber, taken respectively on lines l2-|2 and l3-l3 of Fig. 5, showing the ends of the valve as they appear in one of the operative positions of the valve.

In the practical embodiment of my invention as herein disclosed, I designates a casing having an opening 2 in its top for the introduction of coal into a hopper 3' arranged therein, which opening may be normally kept close by means of a cover 4. The hopper 3 communicates at its bottom with a feed conduit 5 in which is arranged to operate an auger or screw conveyor 6 which is rotated in a manner hereinafter described to feed the fuel to the bottom of a tuyere grate structure 1 arranged within a heating furnace 8. The grate 1 herein shown is of the so-called under-fed type. The conduit 5 extends forwardly from the casing i above or alongside an air feed conduit 9 whereby air to promote and support combustion of the fuel is supplied to the grate, said conduit 9 having arranged therein a suitable type of valve In to permit flow of air to the grate and to prevent its return therefrom. In Fig. 1 thegrate structure I is shown as integral with the conduit 5, but, as shown in Fig. 10, a replaceable elbow 5a may be arranged between the conduit and grate to allow this part of the conduit, most subject to wear, to be economically renewed whenever required.

The auger or screw 6 comprises a suitably journaled shaft II on which the screw proper 6 is mounted. This screw proper comprises a series of sections l2 each longitudinally bored axially to receive the shaft and permit slidable fitting of each auger section on or its removal from the shaft. The series of auger sections may be retained on the shaft against displacement by holding means of any suitable type to prevent their longitudinal displacement while permitting of their removal when required. The meeting faces of adjacent auger sections are constructed to interfit, or they are provided with clutch surfaces l3 for interengagement with each other to hold the sections coupled together. The construction described provides for the ready removal of any portion of the conveyor screw which may become unduly worn or damaged in service and its replacement by a new section without the necessity of the owner of the stoker being compelled to buy a new fully renewal screw. In practice, the shaft may be made of angular shape in crosssection and the bores of the auger section correspondingly shaped so as to adapt the sections to be held against independent rotation on the shaft and to rotate positively with the shaft as the latter is operated.

A part of the casing I is interiorly partitioned to provide a fan or blower chamber I4 communicating with the air duct 9 and a transmission housing or chamber I5 separate from said fan or blower chamber, and which chamber I5 is suitably formed or constructed to provide at its base a reservoir for a storage of a body of oil I6. The outer end of the shaft II extends into the chamber I5 and has mounted thereon a disk or head I! enclosed within or encircled byv the annular body portion I8 of an oscillator I9 having a motion transmitting arm projectingtherefrom. The outer peripheral surface of the disk I! and the inner peripheral surface of the annular body I8 are formed with pockets havingabutment shoulders and inclined surfaces and receiving ball or roller members 2| forming a ball or roller typeof ratchet connection between the shaft and oscillator whereby intermittent or step by step rotation may be imparted to the shaft I I to drive the conveyor 6 on its speed motion. It will be obvious that in one direction of motion the oscillator through the ratchet connection will impart a partial rotation to the shaft in one direction, and that in itsother direction of motionthe ratchet connection will permit the oscillator to move in the reverse directionwithout operating the shaft. The elements I1 and I9 constitute parts ofa. hydraulic transmission mechanism. for imparting from a drive motor, revolving constantly in a single direction at. a relatively high speed, an intermittent or step bystep rotation tothe screw conveyor 6 which is rotatable inits feeding operation at a much lower rate of speed.

The electric motor or prime mover 22 employed for driving the feed screw through suchitrans mission mechanism may be of a conventional standard speedlphase and constant speed type. This motor22-bymeans, of a belt 23 or othertype of gearing drives; a, shaft 24 suitably journaled withimthe casing The shaft 24 in turn operates a blower-orfan 25;wh-ich supplies air to the conduit-9 and also operatestheimpeller of a rotary; oil pump ,26 which communicates with an oil lfeedortsupplypipe 2Iwhich dips down into the body of .oil I6,in.the oil reservoir. The oil so taken up by the pump is forced through a deliverypipeZfl, topthe feed valve mechanism of a; hydraulic motor, generally designated 29, which operates the oscillator I9. The oil on its flow; to the vpipe ,2 8 frorn the pump 26 passes through a pressurespeed regulator of suitable type, and which may include a regulating or throttle valve 3I,- whereby thevolume; and working pressure of theoil, delivered to the pipe 28 may be regulated and controlled.to ;govern the action of the hydraulic motor and the speed of the oscillator I9 and consequently the speed of. rotation of the feed.- .screw- 6.

The hydraulic motor29 comprises a .central valveblock or casing 32 at opposite ends of which are arranged cylinders 33 and 34, which parts are bolted together or otherwise suitably united. In the. cylinder 33 operates a load piston and in. the cylinder 34 operates a reverse orreturn piston 35,. These pistons are of single acting type piston35 operating on its inward movement to transmit a working, motion to the oscillator I9,andpiston. 36.operating on its inwardlmpve:

ment to transmit an idling or return motion to the oscillator. A rod 31 couples the pistons for movement in unison and this rod is suitably coupled to the arm 20 to transmit motion to the oscillator.

In the valve block or casing 32 are formed a manifold chamber 38 having an intake port 39 connecting with pipe 28, a distributor valve chamber 40 and a pilot or reversing valve chamber M, in which chambers 40 and 4 I are arranged sliding distributor and pilot valves 42' and 43. Connecting chambers 40 and 38 are feed ports 55 and 44', and connecting chamber 40 with the outer ends of the respective cylinders are feed and return passages 45 and 45, between which lies an exhaust passage 43 for the return of oil from the cylinders and chamber 40 back to the oil reservoir; In addition to the aforesaid ports and passages the valve casing is provided with passages 47 and 41' connecting opposite ends of the manifold chamber 38 with opposite-endsof the pilotyalve chamber 4'I', passages 48 and 48 connecting opposite. ends of the distributor valve chamber 40 with the ends of the pilot valve chamber 4!, and ventports 4821, 4817' for cooperationwith passages 48, 48,;

The distributorvalve. 42 is provided'with siniilar annular end enlargements or heads 49 which always close communication between the ends of the chamber. 40 and thep'orts 44,.4'4", 45and45. Between these enlarged endportionsor heads 49 the valve is provided :withapair of spaced heads 5!], 50' forming betweenthemannular'ports 5|, 52and 53, whichheads 5B ,andifll and ports 5|, 52 and 53 control communication between the center ports 44, ,45 and 44-,.45' and theportsfi and 45 and port 46. The pilot\ va1ve.43is pro videdadjacent itsrendszwith. annular ports 54 and 55 for. cooperation respectively with thesets ofports 41. and =48-and 4'I' and-48% The valve 43 is also providedwith reduced end extensions or abutments 56 and 56' which project through end walls of the. valvecasing into the respective cylinders 33 and 34-fo1wthe contact-therewith of the pistons '35 and 35110 shift .theyalve 43 in opposite directions fcr effectinga reversing operation of the valve 43. These reduced ends 55. 56' of valve 43- also provide for the exhaust o t-oil through ports.-48, 48" and the vent ports- 4841,4819 from chamber r 4 I in the reversing movements of the valve 43. The valve 43 is gfurther proyidedbetween the-resDfiGtive ports :54 and. 55 and therespective end extensionsi5fi=and 56 with heads 54 and 55. to controlcommunication :between the ports 41, 48,41, 48",'-,48a. and-48b,- as hereinafter described. It'W l1rbQ nd X W0d" ha inpractice the electric motor 22 .is:driven-constantly? in one direction and operates the shaft 24 whichidrives the fan 25 tocontinuously supplyair to thejfurnace grate, the shaft -24valso driving the-pump 26 to supply oil fromthe oil reservoir to'the valve chamber for controlling the workingopervations of Ithe;p istons 3,5,; and :36. 'I'hrough the medium of the regulatonor speed controlleddevice the amount of oil supplied to the-valve chamber and itspressure may be regulated 5 to control the speedof ope-ration ot.- the hydraulic motor, any excess oilnot allowed :topass bythe regulatorv being returned to the-oil reservoir. The supply of OlIfIEOm'thG pump to the controlling valves and: cylinders effectsfirst a working motion of the oscillator in one direction-and then a.return..motion of the-.osc.illator or its movement in the opposite direction, the oscillator in its working movement transmitting (motion in its clutch connection to the feed screw for a coal feed action and on its reverse or return motion acting idly or without motion transmitting efi'ect on the feed screw. The hydraulic motor through the action of the oscillator will actuate the feed screw intermittently at a slow rate of speed, while the motor continues to operate at a uniformly high speed, so that a step by step feed action of the screw on the coal is obtained. In the operation of the pump, hydraulic motor and motion transmitting mechanism, these parts are properly lubricated from the oil or motive fluid supplied from the reservoir, thus reducing the number of parts which have to be lubricated, and if desired the remaining parts of the apparatus may be lubricated by automatic means of suitable type from the same source. Thus those portions of the apparatus with the exception of the feed screw which are the most subject to wear will operate for a long period and, as the use of a valve mechanism of the type described obviates the employment of packings or the like, the liability of derangement of the valve mechanism and the necessity of making repairs thereof will be reduced to the minimum. As speed reduction is obtained with my device without the use of planetary gears, internal pumps and the like, and as no springs are used which are liable to break or become ineflicient, the construction of the apparatus as a whole is considerably simplified, so that it may be manufactured and sold and kept in working order at a comparatively low cost.

Fig. 5 discloses the parts of the hydraulic motor as they appear when the oscillator and load piston are at the limits of their return movements and about to make a power stroke, In this position of the parts the valve 42 has been moved to the right by oil pressure supp-lied through ports and passages 41, 54 and 48 so as to establish communication through passages 44 and 45 between the manifold and cylinder 33 and to establish communication between the exhaust port 45 and the passage 45' with the cylinder 34. In this position of the parts the reversing valve 43 is at the limit of its left hand movement, to which it has been shifted by the previous inward movement of the piston 36, so that its port 54 connects the passages 4'! and 48 and its head 54 closes vent port 48a, while its port 55 lies out of alinement with passages 47' and 48 while its head is in position to close passage 4? and open communication between passages 43, 43b to allow oil to exhaust from 48' over reduced projection 56 and out through port 43b, as shown in Fig. 13, so valve 42 can shift. The projection 56 in this position of valve 43 extends into cylinder 33 so as to lie in the path of inward movement of the piston 35. Fluid pressure thus being supplied to the outer end of the cylinder 33 the piston 35 is moved inward on its working stroke and actuates the oscillator on its Working stroke, piston 36 at the same time being moved outward in its cylinder 34 to force the oil contained therein outward through the exhaust port 46 back to the oil reservoir. When the piston 35 reaches the limit of its inward movement it engages projection 55 of valve 43 and shifts said valve to its right hand end position in which its passage 54 is moved out of alinement with ports 47 and 48 and its passage 55 connects ports 41 and 48, whereby fluid under pressure is supplied to the right hand end of the valve chamber 40 to shift the valve 42 to its left hand position in which it establishes communication between ports 44 and 45' for flow of oil to the outer end of the cylinder 34 and closes communication between ports 44 and 45, While at the same time opening communication between ports 45 and 43 so as to allow exhaust of oil from the cylinder 33 back to the oil reservoir. In such movement of valve 43 its head 54 moves to a position to close port 41 and establish communication between ports 48, 48a to allow oil to exhaust from 48 over projection 56 and out through port 48a, as shown in Fig. 12,. to permit valve 42 to shift to its left hand position. Action of the oil under pressure admitted to cylinder 34 forces the piston 35 inwardly so that the piston 35 will be moved backward to the outer end of its cylinder 33 and so that the oscillatorwill be moved idly back to its initial position ready for another power stroke. The power stroke movement of the piston 35 which shifts the valve 43 to its right hand end position projects its end portion 53 into the cylinder 34, so that when the piston 35 reaches its inward movement it engages the extension 53 and shifts the valve 43 back to its left hand working position for a repetition of the power stroke action of piston 35 previously described. It will be apparent that in these operations great ease of motion of the pistons and valve elements will be obtained so that the working parts will operate in a practically noiseless manner.

The pressure speed regulator 33 may be of any preferred type of construction. As shown in the present instance it comprises a valve casing 51 connected with the outlet or delivery pipe 58 leading from the pump, and which is arranged between said pipe 53 and the delivery pipe 28 leading to the feed valve mechanism of the hydraulic motor. In this casing 51 is arranged the. throttling valve 3| which is adjustable by means. of an operating handle 3| to cause a port 59 in said valve to register to a greater or less extent with the pipes 23 and 53, whereby the flow of oil from the pump to the hydraulic motor may be controlled by a throttling action to regulate its volume of flow and working pressure as desired. Communicating with the pipe 58 between the casing 5'! and the pump is a relief valve chamber 59 having a passage 3| communicating with the pipe 53 and controlled by a valve 62 normally held closed by a spring 53 adapting it to open at a predetermined pressure to provide for the escape of excess oil through an overflow or drain pipe 54 back to the intake of the pump or to the oil reservoir. The spring 53 is disposed between the valve 62 and a threaded plug 65 which is adjustable to enable the pressure of the spring 63 to be regulated and which is adapted to be locked in adjusted position by a lock nut 66.

What I claim is:

1. In a motion transmitting apparatus, a hydraulic motor embodying opposed spaced working and return cylinders and a valve casing between said cylinders, said valve casing having a manifold chamber, a pilot valve chamber opening at its ends into the cylinders, a reversing valve chamber, fluid feed ports connecting the manifold chamber with the ends of the pilot valve chamber, feed ports connecting the manifold chamber with the reversing valve chamber, fluid feed and vent ports connecting the ends of the pilot valve chamber with the ends of the reversing valve chamber, fluid supply and return ports connecting the reversing Valve chamber with the outer ends of the cylinders, and a fluid exhaust port leading outwardly from the reversing valve chamber, load and return pistons respectively operating in said cylinders, means coupling said pistons for movements in nison, a reciprocatory reversing vvalve in said reversing valve chamber shiftable in opposite directions for alternately controlling the flow of, fluid fromthc second-named feed ports through, the supply an return ports to and from the respectivecylinders and its exhaust from the cylinders, through the exhaust port, and a reciprocatory pilot valvein said pilot valve chamber having opnositeend pore tions exposed in the cylinders so as-to be alter-c nately engaged by the respectivepistons for shift, ing the valve in opposite directions, said pilot, valve having end portions governing the first,- named feed ports and the said fluid feed and vent ports to alternately control the feed. of fluidl tor the opposite ends of the reversing valve chamber and its exhaust therefrom.

2. In a motion transmitting apparatus, a. hy-. draulic motor embodying opposed spaced Work ing and return cylinders andv a valve casing: between said cylinders, saidvalve casing having, a manifold chamber, a pilot valve chamber opening at its ends into the cylinders, a re? versing valve chamber, fluid feedrportsconneoting the manifold chamber with the ends of the pilot, valve chamber, feed portsconnecting the manfn. fold chamber with the reversing valve chamber,

fluid feed and vent portsconnecting the .endsof,

the pilot chamber with the endsof the reversing valvechamber, fluid supply and return ports con necting the reversing valve chamber with the outer ends of the cylinders, and a fluid port leading outwardly irom the reversing valve chamber, load and return pistons respectively operating in, said cylinders, a reciprocatory re,- versing valve in the reversing valve chamber come prising, a, cylindrical valve body shiftable longitudinally in said chamber ,andvlhaving heads a e, intervening grooves governing the second-named. Iced ports, the supply and return ports and'the exhaust port for alternately controlling theflow oi fluid from said second-named reed port's through, the supply and return ports toand from r the respective cylind'ersandits exhaust from the:

cylinders through the exhaust port, and, a recip-. rocatory pilot valve in the pilot valve chamber comprisinga cylindrical. valve body longitudinally shiftable in, said chamber and having'opposite end, portions exposed in the cylinders so astuber engaged by the pistons to alternately the. valve in, opposite directions, said va lve. having, end? portions provided, with; heads and mtervening, grooves governing. the first-named feed portsandi thesaidfiuidfeedand vent ports on its-opposite.- shifting movements to alternatelygcontrol: the feed of. fluid to the opposite BIIdSFOf' the reversing valve. chamber and its exhaust therefrom.

ROBERT KLOSSNER.

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