US2041204A - Automatic stoker - Google Patents

Description

M y 19, 1936. J. P. NORTON 2,041,204

AUTOMATIC STOKER Filed Aug. 10, 1953 6 Sheets-Sheet l ,INVENTOR dIqMEs F. NORTON A-'TTORNEY a y 9, J. P. NORTON v 2,041,204

" NW" I n, i If N (I I" I m I m El I ll llillllluu N llhll""""" IN VVVV OR JAMES B NORTON ATTORNEY May 19, 1936. J p, NORTON 2,041,204

AUTOMAT I G STOKER Filed Aug. 10, 1953 6 Sheets-Sheet 4 YINVENTOR JAMES P NORTON BY M 1.

- ATTORNEY 1 J: P. NORTON 4 AUTOMATIC STOKER I May 19, 1936. I

- Filed Aug 10, 1933 s SheetsSheet 5 II I] NORTON 'INVENTOR Fly. 6 JAyE-S' I? 1. 4 s

ATTORNEY May19,193 6. J. P. NCRTON 2,041,204

AUTOMAT I C STOKER Filed Aug. 10, 1953 6 Sheets-Sheet 6 'INVENTOR JAMES P A/oRToN ATTORNEY V Patented May 19, 1936 UNlTED STATES PATENT OFFICE AUTOMATIC STOKER Application August 10, 1933, Serial No. 684,543

15 Claims.

This invention relates to automatic stokers, and more particularly to stokers of the type having a reciprocable ram to feed fuel into a furnace and a rotatablefan wheel to deliver air to the furnace for combustion of the fuel.

The ram in such a stoker must move rather slowly, and preferably at somewhat infrequent intervals, whereas the fan wheel must rotate at high speedv in order to supply air in sufficient quantities and at the needed pressure. Furthermore, it is desirable that both the ram and the fan wheel be driven from a single motor, since this reduces the initial cost of the construction as well as the space required. In addition, it should be possible to vary the frequency of ram reciprocations and thereby control the rate of fuel feed. Considerable difficulty has been encountered in devising an automatic stoker which will include these important features without being complicated and expensive to manufacture. Moreover, many of these stokers have been so bulky as to obstruct the firing aisle and interfere with the opening of the furnace doors and the removal of ashes from the furnace.

It is accordingly one object of the invention to provide an automatic stoker which will be compactly constructed and which will obstruct the firing aisle to a less extent than prior mechanisms for the same purpose.

It is a further object of the invention to provide an automatic stokerincludlng a rotatable fan wheel and a reciprocable ram, together with a single motor to actuate both of said parts, the entire construction being simple, inexpensive and compact.

It is a further object of the invention to pro-.- vide an automatic stoker including a ram reciprocable below a fuel hopper, and anelectric motor. a fan and driving mechanism all compactly ar-- ranged in front of the hopper.

With these and other objects in view, as will be apparent to those skilled inthe art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

In accordance with the preferred embodiment of my invention, I provide a ram which is reciphousing. Both the shaft and the fan wheel arev driven by a single motor, which is preferably an electric motor located close to and in front of the hopper. In the preferred construction, the rotatable shaft is made. hollow to form a quill, and the fan wheel is driven by means of a shaft extending axially through the quill. The quill is provided with an eccentric which serves to reciprocate the ram through the medium of a connecting rod. The fan shaft is driven at a comparatively high speed, preferably by means of a chain and sprocket drive from the motor, and the quill isdriven at a comparatively low speed, preferably by means of a gear train and a speed reducing chain and sprocket drive connecting the motor shaft with the gear train. An automatically actuated clutch is preferably utilized to start and stop the quill at intervals and thus control the frequency of ram reciprocations.

Referring to the drawings illustrating one embodiment of the invention, and in which like reference numerals indicate like parts,

Fig. 1 is a front elevation of an automatic stoker;

Fig. 2-is a side elevation of the stoker, the fan housing being partially broken away to show the internal construction thereof;

Fig. 3 is a section on the line 33 of Fig. 1;

Fig. 4 is a section on the line 4-4 of Fig. 3;

Fig. 5 is an enlarged plan view of the clutch actuating mechanism with the cover plate removed, certain parts being broken away for clearness of illustration;

Fig. 6 is a section on the line 66 of Fig.5;

Fig. '7 is a section on the line 1-1 of Fig. 5;

Fig. 8 is a section on the line B8 of Fig. 5; and

Fig. 9 is a section on the line 9--9 of Fig. 6.

The embodiment illustrated comprises a fuel hopper l mounted adjacent to the front wall ll of a furnace. Beneath the hopper is a horizontal ram casing l2 which communicates through an opening [4 (Fig. 3) in the wall with an underfeed retort l of well-known construction. A ram I6 is arranged to reciprocate in the ram casing l2 and thereby deliver fuel from the hopper l0 through the opening 14 into the retort l5.

In order to deliver air for combustion of the will be delivered beneath the center of the retort l5. Air enters the fan housing i9 through an inlet ring 22 mounted on the outer wall of the fan housing and provided with adjustable dampers 23 arranged to control the rate of air flow. The axis of the fan wheel I! is horizontal and perpendicular to the axis of the ram casing.

The ram I 6 is reciprocated by a driving mechanism comprising a horizontal rotatable shaft 25 mounted in axial alignment with the fan wheel l6 and having an eccentric 26 thereon which is operatively joined to the ram by means of a connecting rod 21. The rear end of the rod 21 is pivoted to the ram by means of a wrist pin-28 (Fig. 3). The shaft 25 is supported in two bearings 33 and 3i located close to the eccentric 26 and on opposite sides thereof. The bearing 80 is formed in the adjacentinner wall of the, fan housing i9, and the bearing 3| is formed in the adjacent inner wall of a box or casing 82 which serves to enclose a speed-reducing mechanism to be described hereinafter. This box 32 is provided with a cover plate 33 which can be removed to allow access to the interior. In the preferred construction the box 32 and the fan housing I! are formed by a single casting which rests upon a suitable foundation and serves to support the front end of the ram casing i2, thereby providing a very strong and rigid structure.

The eccentric 26 preferably has a diameter somewhat greater than the stroke of'the ram, and the shaft 25 is made hollow to form a quill. This makes it possible to extend a rotatable shaft 35 through the center of the quill and utilize this shaft to drive the fan wheel l8. As shown particularly in Fig. 4, the fan wheel is mounted on one end of the shaft 35. The shaft 35 is supported near the fan wheel by means of a roller bearing 36 mounted in the quill 25, and the shaft is supported near its other end in roller bearings 31 and 38 mounted in a sleeve 46, which in turn is rotatably supported in a bearing 4| formed in the outer wall of the box 32.

In order to drive the stoker I have shown an electric motor 42 mounted on the ram casing l2 directly in front of the hopper Hi, the shaft 43 of the motor being parallel to the fan shaft 35. The motor shaft 43 carries a sprocket wheel ll (Fig. 4) which is connected by means of a chain 45 to a sprocket wheel 46 mounted on the end of the fan shaft 35. The wheels 44 and 46 are shown equal in diameter, so that the fan wheel II will be driven at the same speed as the motor shaft 43. This speed may be relatively high, for example 1800 revolutions per minute. The motor sprocket wheel 64 is made double and is connected by means of a second chain 68 to a sprocket wheel I! on the outer end of the sleeve 46. These two chain drives are enclosed in a suitable casing 56. The sprocket wheel 48 is considerably larger in diameter than the wheel 44, so that the sleeve 48 will rotate at a much slower speed than the motor shaft. However, the speed of the sleeve 66 is higher than is desirable for the ram driving quill 25, and I therefore use a suitable speed reducing mechanism to connect these parts. For this purpose I provide a pinion on the inner end of the sleeve 46, and I utilize this pinion to drive a gear 52 in mesh therewith. A pinion 53 is fixed to the gear 52 in a coaxial relationship, these parts forming a compound gear which is rotatably supported on a oountershaft 54 mounted in the box 32 beneath and parallel with the shaft 35. The pinion 52 meshes with a gear 55 mounted on the quill 25.

It is ordinarily desirable to operate the ram intermittently rather than continuously, and I therefore mount the gear 55 on a roller bearing 56 (Fig. 4) on the quill 25, and I provide an automatically actuated clutch mechanism to connect the gear to the quill at predetermined intervals. As shown particularly in Fig. 4, the quill 25 is extended axially toward the sleeve 60, and an annular hub 58 is keyed firmly to the extended portion of the quill. Anannular clutch member- 56 is keyed to the hub 58 and arranged to slide thereon in an axial direction. The member 55 and the gear 55 are provided with cooperating clutch teeth 66 and 6| respectively which engage when the clutch membbr is moved toward the gear, and thus form a driving means for the quill 25. Coiled compression springs 62 are provided between the hub 58 and the clutch member 58 to urge the latter toward its driving position.

In order to control the movements of the clutch member 59, I provide the mechanism shown particularly in Figs. 5 to 9 inclusive. The member 59 is provided on its periphery with a cam in the form of an outwardly extending rib 66 having the leading portion 65 of its operative surface inclined rearwardly and laterally toward the gear 55. The clutch member may be held in its released position, against the pressure of the springs 62, by means of a pin 66 which extends radially of the clutch member at the front thereof and engages the side of the cam 6|. The pin 66 is axially slidable in a bearing 61 formed on a bracket 68 mounted in the box 32. A U-shaped yoke is secured to the front of the pin 66, and a pin H extends forwardly from the yoke 10 in axial alignment with the pin 66. The pin II is slidably supported in a. bearing 12 formed on the bracket 68, and a coiled compression spring 13 surrounds the pin ll between the bearing I2 and the yoke 16, this spring being arranged to urge the pin 66 rearwardly toward the clutch member 59. A knob 14 is mounted on the front end of the pin ll outside of the casing, so that the parts can be held manually against the pressure of the spring 13 if desired. A pin extends rearwardly from the yoke 10 into slidable engagement with the bearing 61 to prevent turning of the yoke.

In order to withdraw the pin 66 automatically at predetermined intervals, I form a tooth I6 on the yoke 'lll,'and I provide a rotatable cam 11 which will engage this tooth at each revolution and move the pin 66 out of contact with the cam 64. This rotatable cam 11 is advanced by means of a ratchet mechanism comprising a hollow cylindrical casing 18 to which the cam 11 is secured. Inside the casing 16 is a rotor 19 (Fig. 8) having peripheral notches 86 which gradually decrease in depth toward one end, a roller 8i being located in each notch to engage the inner peripheral surface of the casing 18. With this construction clockwise movement of the rotor will cause the rollers 8| to bind against the casing 18 and move the same, whereas if the movement of the rotor is reversed the rollers will release their grip and the casing will remain stationary.

The rotor 19 is keyed to a shaft 83 arranged parallel to the shaft 35 and mounted in bearings 84 and 85 formed on the bracket 68. A dog 86' is secured to the shaft 83 and extends rearwardly into the path of a roller 81 mounted on the side of the gear 55. The upward movement of the dog 86 is limited by a lug 58 thereon which engages a lug 98. A coiled tension spring 9| extends between the bracket 68 and the dog 86 to urge the lug 89 into contact with the lug 55.

In order to permit an adjustment of the rate position of the lug 98 and thereby vary the extent of oscillation of the dog 88. For this purpose'the lug 98 is formed on the hub of a bevel gear 93 whichis rotatably supported on the shaft 83. A

screw 94 is mounted in the gear 93 and engages a peripheral groove 95 in the shaft 83 to prevent axial movement of the gear. The gear 93 meshes with a second bevel gear 96 mounted on a shaft 91 which is supported in a bearing 98 formed on the bracket 68. .The shaft 91 extends forwardly through the front wall of the box 32 and carries on its front end an operating handle 89. The handle 89 is recessed at its upper end to receive a ball l8! (Fig. 7) which is pressed upwardly by a coiled compression spring I82 into engagement with a notched segmental plate I83 mounted on the bearing 98.

The operation of the invention will now be apparent from the above disclosure. The motor 42 drives the chain 45 and the shaft 35, thus rotating the fan wheel i8 at a high speed and forcing air for combustion through the duct and the gear 52 and pinion 53 to the gear 55, which rotates slowly on the roller bearing 56. At each rotation of thegear 55, the roller 81 will strike the dog 86 and turn the shaft 83 in a clockwise direction as viewed in Fig. 7. When the roller has moved out of contact with the dog, the spring 9| will return the dog to its original position as determined by the stop 98. By moving the handle 98 to various notches in the plate I83, the stop 98 can be adjusted to different positions through the medium of the shaft 91 and the bevel gears 98 and 93. In this way the extent of oscillation of the shaft 83 can be adjusted. As the shaft 83 oscillates, it acts through the ratchet mechanism 18 to advance the cam i1 intermittently in a clockwise direction, and when this cam strikes the tooth 16 it will move the yoke 18 and the pin 66 forward- 1y. Th pin 66 will thus move out of contact with the cam 64 and allow the springs 82 to force the clutch member 59 axially toward the gear 55,

, bringing the teeth 68 into the path of the teeth 6 I.

As a result the clutch member 59, hub 58, quill 25 and eccentric 26 will start to rotate with the gear 55, causing the ram Hi to reciprocate and feed a charge of fuel from the hopper l 8 into the retort I5. Before the eccentric has completed one revolution, the roller 81 will strike the dog 86 again tooth, as would occur when the handle 99 is ad justed for a high feeding rate and the cam I1 is consequently advanced through a large angle at each revolution of the gear 55.) This will, allow the spring I3 to throw the yoke 18 and pin 66 rearwardly, and as the eccentric completes one revolution the beveled portion 65 of the cam 64 will strike the pin 66 and force the clutch member 59 axially away from the gear 55, moving the teeth 68 out of contact with the teeth iii and bringing the eccentric and the ram to a stop. It will thus be seen that a charge of. fuel is delivered to the furnace at each revolution of the cam 11, and the rate of advance of this cam can be controlled by adjusting the conveniently located handle 99. If it is desired to operate the ram continuously for a short time, for example in banking the fire, it is merely necessary to pull the knob 14 forwardly against the pressure of the spring 13, thus allowing the clutch to remain enazed.

It will be noted that the invention provides a very compact construction, which is moreover simple and inexpensive to manufacture and install. The fan and the ram are both driven from accessible for inspection or lubrication but also out of the way of any water or ashes which may accumulate on the firing aisle floor. This motor requires a shaft extension at oneend only, and may be of standard construction. It will also be noted that by reason of the positioning of the box 32 and the fan housing l9 on opposite sides of the eccentric 26 the space available is used to great advantage. A comparatively small floor space is required, and the structure approximates a symmetrical arrangement about the centerline of the ram casing II. This makes it possible to utilize inspection doors and ash removal doors at each side of the stoker if desired without interference with any of the stoker parts. Furthermore, the ram casing is located much lower than is possible in former constructions in which the fan is placed beneath the fuel feeding mechanism. For this reason the stoker is well suited for installation in connection with boilers which are set unusually low. No external countershafts are employed. The stoker is entirely self-contained and can be built and assembled in the shop, so that all diflicult problems of aligning bearings in the field have been eliminated. All moving parts are fully enclosed, and yet they are readily accessible for inspection or replacement upon removal of the cover plate 33. The clutch timing mechanism can be completely assembled on the bracket 68 and subsequently mounted in its proper place in the box 32. This considerably reduces the cost of manufacture.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An automatic stoker comprising a ram casing, a fuel-feeding ram reciprocable therein, a hollow rotatable shaft having an eccentric there, on, driving means for the ram'including a connecting rod operatively connected with the eccentric, a fan housing, a rotatable fan wheel mounted in the fan housing, and a rotatable shaft extending through the hollow shaft and connected to the fan wheel.

2. An automatic stoker comprising a ram casing, a fuel-feeding ram reciprocable therein, a rotatable quill in front of the ram casing and having an eccentric thereon, a connecting rod joining the eccentric with the ram to drive the same, a rotatable shaft extending through the quill, a fan housing anda fan wheel mounted in the fan housing and driven by said shaft.

3. An automatic stoker comprising a ram casing, a fuel-feeding ram reciprocable therein, a quill rotatable about a substantially horizontal axis in front of the ram casing and having an eccentric thereon, a connecting rod joining the eccentric with the ram to drive the same, a rotatable shaft extending through the quill, a fan housing, and a fan wheel mounted in the fan housing, said fan wheel being coaxial with the shaft and driven thereby.

4. An automatic stoker comprising a ram casing, a fuel feeding ram reciprocable therein, a fan housing in front of the ram casing, a'speedreducing mechanism in front of the ram casing,

the speed-reducing mechanism and fan housing being laterally adjacent and located on opposite sides of the center of the ram casing, a quill rotatable about a substantially horizontal axis in front of the ram casing and having an eccentric thereon located between the speed-reducing mechanism and the fan housing, a connecting rod joining the eccentric with the ram to drive the same, driving connections between the speed-reducing mechanism and the quill, a rotatable shaft extending through the quill, and a fan wheel mounted in the fan housing and driven by the shaft.

5. An automatic stoker comprising a ram cas-' ing, a fuel feeding ram reciprocable therein, a fan housing in front of the ram casing, a box in front of the ram casing, the fan housing and the box being laterally adjacent and located on opposite sides of the center of the ram casing, a quill rotatable about a substantially horizontal axis in front of the ram casing and supported in bearings on the adjacent walls of the box and fan housing, the quill having an eccentric thereon located between the box and the fan housing, a connecting rod joining the eccentric with the ram to drive the same, a speed-reducing mechanism in the box, driving connections between the speedreducing mechanism and the quill, a rotatable shaft extending through the quill, and a fan wheel mounted in the fan housing and driven by the shaft.

6. An automatic stoker comprising a ram casing, a fuel-feeding ram reciprocable therein, a fan housing in front of the ram casing, a box in front of the ram casing, the fan housing and the box being laterally adjacent and located on opposite sides of the center of the ram casing, a quill rotatable about a. substantially horizontal axis in front of the ram casing and supported in bearings on the adjacent walls of the box and fan housing, the quill having an eccentric thereon located between the box and the fan housing, a connecting rod joining the eccentric with the ram to drive the same, a speed-reducing mechanism in the box, driving connections between the speedreducing mechanism and the quill, a rotatable .shaft extending through the quill, a fan wheel mounted in the fan housing and connected to one end of the shaft, and an electric motor arranged to drive both the speed-reducing mechanism and the rotatable shaft.

7. An automatic stoker comprising a fuel hopper, a ram casing beneath the fuel hopper and in communication therewith, a ram reciprocable in the ram casing, a fan housing in front of the ram casing, a box in front of the ram casing, the fan housing and the box being laterally adjacent and located on opposite sides of the center of the ram casing, a quill rotatable about a substantially horizontal axis in front of the ram casing and supported in bearings on the adjacent walls of the box and fan housing, the quill having an eccentric thereon located between the box and the fan housing, a connecting rod joining the eccentric with the ram to drive the same, a speedreducing mechanism in the box, driving connections between the speed-reducing mechanism and the quill, a rotatable shaft extending through the quill, a fan wheel mounted in the fan housing and connected to one end of the shaft, an electric motor mounted above the ram casing and in front of the fuel hopper, and power transmitting means connecting the motor with the speed-reducing mechanism and the shaft.

8. An automatic stoker comprising a ram casing, a fuel-feeding ram reciprocable therein, a quill rotatable in front of the ram casing and having an eccentric thereon, a connecting rod joining the eccentric with the ram to drive the same, a rotatable shaft extending through the quill, a fan housing, a fan wheel mounted in the fan housing, said fan wheel being coaxial with the shaft and driven thereby, a rotatable sleeve surrounding the shaft, speed-reducing mechanism driven by the sleeve, driving connections between the speed-reducing mechanism and the quill, an electric motor, and power transmitting means connecting the motor with the shaft and sleeve to rotate the shaft at a high speedand the sleeve at a lower speed.

9. An automatic stoker comprising a ram casing, a fuel-feeding ram reciprocable therein, a quill rotatable about a substantially horizontal axlsin front of the ram casing and having an eccentric thereon, a connecting rod joining the cocentric with the ram to drive the same, a rotatable shaft extending through the quill, a fan housing, a fan wheel mounted within the fan housing, said fan wheel being connected to one end of the shaft and driven thereby, a rotatable sleeve surrounding the shaft at the opposite end of the quill from the fan wheel, a pinion on the sleeve, 9. gear on the quill, means to operatively connect the gear with the quill, means including a compound gear connecting the pinion with the gear to drive the same, an electric motor, and two chain and sprocket drives connecting the motor with the shaft and the sleeve respectively to rotate the shaft at a high speed and the sleeve at a lower speed.

10. An automatic stoker comprising a fuel hopper, a ram casing beneath the fuel hopper and in communicationitherewith, a ram reciprocable in the ram casing, a fan housing in front of the ram casing, a box in front of the ram casing, the fan housing and the box being laterally adjacent and located on opposite sides of the center of the ram casing, a quill rotatable about a substantially horizontal axis in front of the ram casing and supported in bearings on the adjacent walls of the box and fan housing, the quill having an eccentric thereon located between the box and fan housing, a connecting rod joining the eccentric with the ram to drive the same, a rotatable shaft extending through the quill, a fan wheel mounted in the fan housing and connected to one end of the shaft, a rotatable sleeve surrounding the shaft at the opposite end of the quill from the fan wheel, a pinion on the sleeve, 8. gear on the quill, means to operatively connect the gear with the quill, means including a compound gear located beneath the shaft and connecting the pinion with the gear to drive the same, an electric motor mounted above the ram casing and in front of the fuel hopper, and two chain and sprocket drives connecting the motor with the shaft and the sleeve respectively to rotate the shaft at a high speed and the sleeve at a lower speed.

11. An automatic stoker comprising a ram casing, a fuel-feeding ram reciprocable therein, a quill rotatable in front of the ram casing and having an eccentric thereon, a connecting rod joining the eccentric with the ram to drive the same, a rotatable shaft extending through the quill, a fan housing, a fan wheel mounted in the fan housing, sa d fan wheel being coaxial with the shaft and driven thereby, a gear coaxial with the quill, means to rotate the shaft at a high speed and the gear at a low speed, a clutch to connect the gear with the quill, and means to actuate the clutch automatically at predetermined intervals.

12. An automatic stoker comprising a ram casing, a fuel feeding ram reciprocable therein, a. quill rotatable in front of the ram casing and having an eccentric thereon, a connecting rod joining the eccentric with the ram to drive the same, a rotatable shaft extending through the quill, a fan housing, a fan wheel mounted in the fan housing, said fan wheel being coaxial with the shaft and driven thereby, a gear rotatably supported on the quill, means to rotate the shaft at a high speed and the gear at a low speed, an annular clutch member slidably keyed to the quill, the clutch member and gear having cooperating parts which engage at one position of the member and thus cause the member to rotate with the gear, and means to slide the clutch member along the quill at predetermined intervals and thus cause intermittent rotation of the quill.

13. An automatic stoker comprising a ram casing, a fuel-feeding ram reciprocable therein, a quill rotatable in front of the ram casing, an eccentric on the quill, a connecting rod joining the eccentric with the ram to drive the same, a rotatable shaft extending through the quill, a fan housing, a fan wheel mounted in the fan housing, said fan wheel being coaxial with the shaft and driven thereby, a rotatable sleeve surrounding the shaft, speed-reducing mechanism connecting the sleeve with the quill to rotate the same, an electric motor, and two chain and sprocket drives connecting the motor with the shaft and the sleeve respectively to rotate the shaft at a high speed and the sleeve at a lower speed.

14. An automatic stoker comprising a ram casing, a fuel-feeding ram reciprocable therein, a fan housing in front of the ram casing, a box in front of the ram casing, the fan housing and the box being laterally adjacent and located on opposite sides of the center of the ram casing, a speedreducing mechanism in the box, a horizontal r0 tatable shaft driven by the speed-reducing mechanism, the box and the fan housing being shaped to provide two spaced bearings which support the shaft, a connecting rod, means on the shaft between the two spaced bearings to drive the connecting rod, the connecting rod being connected to the ram and to the means for driving the connecting rod, a rotatable fan wheel in the fan housing, and means to drive the speed-reducing mechanism and the fan wheel.

15. An automatic stoker comprising a fuel feeding device, a hollow rotatable shaft, means operatively connecting the shaft with the fuel feeding device to drive said device, a fan housing, a

rotatable fan wheel mounted in the fan housing, i

and a rotatable shaft extending through the hollow shaft and connected to the fan wheel.

JAMES P. NORTON.

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