US3640233A

US3640233A - Incinerator shiftable closure gate

Info

Publication number: US3640233A
Application number: US79038A
Authority: US
Inventors: Joel Russell Reiner; William J Preusch; William G Davenport
Original assignee: BEAUMONT BIRCH CO
Current assignee: BEAUMONT BIRCH CO
Priority date: 1970-10-08
Filing date: 1970-10-08
Publication date: 1972-02-08
Anticipated expiration: 1989-02-08

Abstract

A wheeled closure gate for maintaining opened or closed as desired an aperture disposed in a substantially horizontal plane, the gate being shiftable along tracks embracing the aperture which are so relatively inclined with respect to the horizontal plane as to permit the gate to be moved upwardly along said tracks by power means into aperture-opening position and return thereof by gravity into aperture-closing position. The closure gate in this particular instance comprises a flat plate assembly which is bodily shifted from its aperture-closing position, as across the top of a charging hopper or across the top of an exhaust port, into an inclined position located immediately adjacent to one end of the aperture to completely expose the same for flow of material therethrough. Means are provided to controllably hold the gate in its power-operated raised position and to release it for gravity return to its lowered position. The tracks for and roller wheels of the gate are protected against the accumulation of debris thereon as might interfere with free movement of the gate. The gate when raised into its open position serves, when employed as a cutoff gate for an incinerator charging hopper, to deflect back into the hopper rubbish which would otherwise not be received by the hopper. The opposite sidewalls of the hopper may be also provided with swingable side covers which serve to shield the tracks and wheels of the gate from debris collecting thereon and to deflect back into the hopper rubbish spilling over the sidewalls of the hopper.

Description

United States Patent Reiner et al.

[ 1 Feb. 8, 1972 [54] INCINERATOR SHIFTABLE CLOSURE GATE [72] lnventors: Joel Russell Reiner, Philadelphia; William J. Preusch, Southampton; William G. Davenport, Philadelphia, all of Pa.

[73] Assignee: Beaumont Birch Company, Philadelphia,

[22] Filed: Oct. 8,1970

[21] Appl.No.: 79,038

..ll0/8 R, 110/173 R Primary Examiner-Kenneth W. Sprague plane, the gate being shiftable along tracks embracing the aperture which are so relatively inclined with respect to the horizontal plane as to permit the gate to be moved upwardly along said tracks by power means into aperture-opening position and return thereof by gravity into aperture-closing position. The closure gate in this particular instance comprises a flat plate assembly which is bodily shifted from its apertureclosing position, as across the top of a charging hopper or across the top of an exhaust port, into an inclined position located immediately adjacent to one end of the aperture to completely expose the same for flow of material therethrough. Means are provided to controllably hold the gate in its poweroperated raised position and to release it for gravity return to its lowered position. The tracks for and roller wheels of the gate are protected against the accumulation of debris thereon as might interfere with free movement of the gate. The gate when raised into its open position serves, when employed as a cutofi' gate for an incinerator charging hopper, to deflect back into the hopper rubbish which would otherwise not be received by the hopper. The opposite sidewalls of the hopper may be also provided with swingable side covers which serve to shield the tracks and wheels of the gate from debris collecting thereon and to deflect back into the hopper rubbish spilling over the sidewalls of the hopper.

Attorney-Edelson & Udell 24 Claim 22 Drawillg 9 [57] ABSTRACT A wheeled closure gate for maintaining opened or closed as desired an aperture disposed in a substantially horizontal '35 I" l9 7 II I II7IIIIIII l zIIIIIIIIIIIIIlIIIlI/IIIIIII/ll 'I/ PATENIEU rm BIBTZ SHEET 5 or a INCINERATOR SHIFIABLE CLOSURE GATE This invention relates generally to incinerator apparatus and more particularly to improvements in gates for opening and closing as required the hopper through which charges of 5 rubbish to be burned are introduced into the incinerator combustion chamber and for closing and opening as desired exhaust ports through which gases of combustion may be exhausted externally of the incinerator furnace.

In the operation of the conventional incinerators presently in use, loads of the rubbish to be burned are successively lifted from the ground to an elevated point from whence such loads are successively deposited into a hopper which feeds the rubbish by gravity flow through a suitable refractory throat communicating with the combustion chamber wherein the rubbish is stoked for burning upon grates which dump the residual ash upon continuously moving endless conveyors for transfer of the ash to a suitably located discharge and collecting point. As the rubbish is burned, the gases of combustion are normally exhausted from the combustion chamber through an exhaust stack by the forced draft of a blower located at the base of the stack.

So long as the rubbish to be burned is fed more or less continuously into the hopper so as to maintain the hopper throat substantially filled with the rubbish being supplied to the incinerator furnace, there is little, if any, back draft developed to interfere with proper exhaust of the furnace gases through the stack. However, should there be a lag in the process of charging the hopper, as may occur several times during a normal operating shift of the incinerator, so that the hopper and its throat are substantially free of rubbish, an up draft may develop therethrough in opposition to the natural or forced normal draft from the combustion chamber to and through the outlet, such as the conventional exhaust stack, for exhausting the gases of combustion from the incinerator combustion chamber. Thus, whenever the charging of the incinerator with rubbish to be burned is interrupted, the hopper or its throat must be immediately closed, this being conventionally accomplished by so-called cutoff gates which are shiftable into closed and open positions by movement in a horizontal plane across the path of flow of the rubbish introduced into the hopper. These cutoff gates, which in some installations move across the top of the hopper and in other installations move through and across the base of the hopper or the hopper throat itself, are quite massive and heavy and require considerable effort to shift them into their closed and open positions. Also, since these conventionally employed cutoff gates shift in a horizontal plane, upon movement thereof into their closed positions they may have deposited upon their upper surfaces substantial accumulations of the hopper-charging rubbish, which accumulations interfere with the free movement of the gate and foul up the operating mechanisms for the same. This can result in failure to effect complete closing of the gate in emergency situations requiring that the gate be quickly and effectively closed tight, as in the case of a fire flaring up through the incinerator charging throat and its associated hopper.

Having in mind the foregoing, itis among the principal objects of the present invention to provide an incinerator charg' ing cutoff gate which may be readily withdrawn from a horizontally disposed position in which it rests flatly upon and effectively seals closed the open top of the charging hopper into an inclined position substantially free of the hopper to completely open the latter for receiving charges of the rubbish to be burned and from which inclined position the gate may be released for return movement into its hopper sealing position solely by the force of gravity acting under the influence of the weight of the gate itself.

A further object of the invention is to provide a hopper charging cutoff gate which while shiftable into its hopper opening position by suitable power means, does not require any power means for quickly and effectively shifting it into its hopper closing position, for which purposes the gate is provided withoperating means adapted to be remotely controlled.

Still another object of the present invention is to provide a hopper charging cutoff gate which is adapted to be raised from a flat, horizontal position closing ofl' the top of the charging hopper into an inclined position at the rear end of the hopper to completely open the hopper for reception of rubbish to be burned and with the cutoff gate in its said inclined position serving as a means for deflecting back into the hopper rubbish which 'would otherwise spill over the rear end of the hopper duringthe charging thereof.

The present invention also has among its objects the provisionof means for maintaining substantially free of debris and rubbish tracks and rollers associated with the hopper and its cutoff, including for this purpose auxiliary side covers each swingable into open and closed positions relatively to the opposite sidewalls of the hopper, these side covers when in their closed positions serving not only as means for deflecting rubbish spilling over sides of the hopper during charging thereof into rubbish collecting pits or the like extending along the oppositeiside of the incinerator, but. also as means for shielding the side tracks and roller wheels of the gate against excessive deposit and accumulation thereon of rubbish during charging of the hopper.

Since these side covers must be swung into their open posi tions during the operations of shifting the cutoff gate into either its open or its closed position relatively to the charging hopper, it is a further object of the present invention to provide'rfleans controllable from a remote operatingstation for expeditiously effecting the required swinging of the side covers into and out of their hopper engaging positions.

Stillanother important object of the present invention is to provide a shutoff gate or cover of such design, construction and operation as may enable it to be employed not only as a hopper charging cutoff gate as hereinbefore mentioned but also as an exhaust relief gate for opening and closing as maybe required an auxiliary port provided in the top of the incinerator for emergency exhaust of the gases of combustion from the incinerator furnace. To this end the opening and closing of the shiftable closure of the present invention, when so employed as an exhaust relief valve, is under control of a counterweight system which is operative, upon failure of electric power for operating the gas exhaust blower normally employed in the incinerator for forced draft and discharge of gases through the stack of the incinerator to automatically open the auxiliary relief valve for natural draft discharge of the combustion gas.

Other objects and advantages of the present invention will be apparent from the following detailed description thereof, it being understood that the invention consists in the construction combination and relative arrangement of parts as hereinafter described, as shown in the accompanying drawings and as finally pointed out in the appended claims.

In the accompanying drawings:

FIG 1 is a diagrammatic view showing generally in side elevation the applications of the present invention to an incinerator;

FIG. .2 is a side elevational view showing a shiftable cover constructed in accordance with and embodying the principles of the present invention as installed in an incinerator for closing and opening the charging hopper thereof; the cover being shown in its closed position;

FIG.:3 is a view similar to FIG. 2 but showing the cover for the charging hopper shifted into its open position;

F1014 is a top plan view of the cover, shown partly broken away to expose the charging hopper, as viewed from the line 4-4 of FIG. 2;

FIG. 5 is a fragmentary front elevational view of the charging hopper and its cover as viewed from the line 5-5 of FIG.

FIG; is a longitudinal sectional view of the incinerator charging' hopper and its cover as taken along the line 66 of FIG. 4;

FIG. 7 is an enlarged side elevational view of that portion of the apparatus which is inscribed by the circle 7 of FIG. 2 showing the cover in its detained fully closed position;

FIG. 8 is a transverse sectional view as taken along the line 8-8 of FIG. 7;

FIGS. 9 and 10 are views respectively similar to those of FIGS. 7 and 8 but which show the cover of the charging hopper shifted out of its normally detained closed position for movement into its fully opened position;

FIG. 11 is an enlarged side elevational of that portion of the apparatus which is inscribed by the circle 11 of FIG. 2 showing the cover in its fully opened position;

FIG, 12 is a view similar to FIG. 2 but showing a modified means for shifting the cover into and out of its closed position;

FIG. 13 is a fragmentary side elevational view of the righthand portion of FIG. 12 showing the cover shifted into fully opened position relatively to the charging hopper;

FIG. 14 is a view similar to FIG. 13 showing the cover raised beyond its normal opened position to provide access beneath and behind the same for which servicing thereof and/or cleaning its free of accumulated debris as may be required;

FIG. 15 is a top plan view, partially sectioned, as taken along the line 15l5 of FIG. 12;

FIG. 16 is a partial front elevational view as seen from the line 16-16 ofFIG. 12;

FIG. 17 is a detail perspective view of the portion of the frame structure inscribed within the circle 17 of FIG. 12;

FIG. 18 is a detail perspective view of the portion of the frame structure inscribed within the circle 18 of FIG. 12;

FIG. 19 is a front elevational view ofa hopper fitted with the shiftable cover of the present invention, the hopper in this case being shown provided at its opposite sides with remote controlled fluid pressure operated swingable side covers for preventing material spilling over the top edges of the hopper as it is being loaded from being deposited upon the tracks extending along the sides of the hopper with resulting interference with free movement of the hopper cover along said tracks;

FIG. 20 is a fragmentary side elevational view of the hopper side cover as seen from the line 20-20 of FIG. 19;

FIG. 21 is a view showing the inner face construction of one of the hopper side covers as viewed from the line 21-21 of FIG. 19; and

FIG. 22 is an elevational view of an alternate arrangement for safely retaining the hopper cover in its fully extended position as shown in FIG. 14.

Referring now more particularly to the drawings, FIG. 1 shows the closure gate of the present invention applied to an incinerator as a cover for closing off the top of a hopper through which trash to be burned is introduced into the incinerator and also as a closure for an auxiliary exhaust port through which the gases of combustion may be discharged to atmosphere instead of through the usual gas discharge stack in the event that the latter becomes inoperative for any reason.

The incinerator, designated generally by the reference numeral 10, may be of any conventional construction having a furnace chamber 11 equipped with grates 12 for burning refuse deposited upon the grates by way of a charging hopper 13 having a depending throat or chute 14 leading to the grates. The gases of combustion are normally drawn rearwardly out of the furnace chamber for discharge to atmosphere under the influence of an electric-motor-driven blower 15 located at the base end of an exhaust stack 16. In the incinerator as illustrated, an auxiliary exhaust port 17 is provided just ahead of the opening into the exhaust stack for effecting a natural draft exhaust of the combustion gases from the furnace chamber in the event of an emergency failure of operation of the motor driven blower 15 for forced draft of the gases through the exhaust stack 16.

Both the refuse charging hopper 13 and the auxiliary gas discharge port 17 are fitted with shiftable covers or gates respectively designated 18 and 19, each of which gates is constructed and adapted to be operated in accordance with the principles of the present invention. Except for possible variations in the location and mounting of the gates to best accommodate the same for use either as the closure for the hopper or us the closure for the auxiliary port, the gates, irrespective of their use, are in all material respects generally similar in construction and in operation.

The refuse to be burned in the incinerator is elevated by any suitable means to a point just above the incinerator hopper into which it is dropped and from which it is discharged by gravity into the furnace chamber and onto the grates for movement of the residual ash and other unburned products of combustion to a discharge point, such as a channel 20 having therein a suitable ash conveyor mechanism (not shown).

When the blower 15 is in normal operation for forced draft exhaust of the gases of combustion through the stack 16, the closure gate 19 for the auxiliary exhaust port 17 is, of course, maintained closed, as is the closure 18 for the charging hopper 13 except for the intervals when the gate 18 is necessarily open for loading refuse to be burned into the hopper. So long as the charging hopper and its throat are substantially filled with rubbish to be incinerated, as is the case when the hopper is being more or less continuously loaded with rubbish, there is little likelihood of a back draft being created sufficient to interfere with efficient exhaust of the gases of combustion through the stack 16. However, should the hopper throat be substantially free of rubbish during operation of the incinerator, such an undesired result may then well result and to prevent this the charging hopper gate is desirably maintained closed at all times that the charging hopper and its throat are substantially free of rubbish.

If for any reason, such as the occurrence of an electric power failure, the blower 15 should become inoperative with resultant failure of draft through the exhaust stack 16, the auxiliary port closure gate 19 may be opened to provide for natural draft exhaust of the gases of combustion from the combustion chamber of the incinerator.

Since the

closure gates

18 and 19, although employed for different purposes in the incinerator as shown in FIG. 1 are essentially similar in construction and operation, only the hopper charging gate 18 and its supporting structure and operating pasts will now be described in detail.

Referring now to the apparatus of FIGS. 2 and 8 and more particularly to FIGS. 2 and 3, it will be observed that the closure gate 18 is designed to be shifted across the open top of the incinerator charging hopper 13 to selectively open or close the hopper as may be desired during operation of the incinerator. It will also first be noted that this hopper is provided with downwardly conveying opposite sidewalls 21-21 and downwardly converging front and rear walls 22-23 (as see FIG. 4), all of which walls are so upwardly extended as to provide an open top bounded by perimetral edges disposed in a common plane.

Extending lengthwise along the opposite sidewalls 2121 of the hopper just below the top edges thereof are a pair of rails or tracks 2424 each of right-angle section to provide an outwardly presenting wheel-engaging flange 25. These rails or tracks 2424 are supported in any suitable manner, as by the hopper-supporting struts 26, to extend in a common plane which slopes downwardly and forwardly lengthwise of the incinerator and for disposition of their wheel-engaging flanges respectively below the top edges of the hopper sidewalls, as is best shown in FIG. 8.

The closure gate 18, which is of a shape generally corresponding to that of the open top of the hopper, comprises a solid steel top plate 27 braced and reinforced by I-beams 28 which are secured to its undersurface and extend transversely thereacross at spaced intervals, as see FIG. 6. These transversely extending reinforcing beams 28 for the cover plate 27 are respectively provided with bottom brackets 28a of stepped depth, as best shown in FIG. 6, which have secured to their bottom ends a rectangular bottom frame member 29 which is adapted, when the gate 18 is in its closed position, to seat flatwise upon the top perimetral edges of the hopper. The cover to plate 27, its bottom frame 29 and the crossbeams 28 secured therebetween are all of a transverse dimension exceeding the width of the hopper top so that the cover assembly as just described overhangs opposite sides of the hopper, as is best shown in FIGS. 8 and 10. These overhanging opposite side portions of the cover assembly are respectively rigidly interconnected by side channel members 30 which extend lengthwise along opposite sides of the cover assembly and are each of a depth to embrace and seal the opposite side openings between the spaced top and

bottom members

27 and 29 of the cover assembly. Also, it will be noted (as see FIG. 2) that each side channel member 30 of the cover assembly is provided with an end portion 300 which extends rearwardly beyond the rear edge of the cover plate.

These side channel members each have suitably mounted at the fore and aft ends thereof a front roller wheel 31 and a rear roller wheel 32 both of which are adapted, when the hopper cover 19 is in its closed position, to rest upon the outwardly presenting flange 25 of the wheel supporting rail or track 24. These

wheels

31 and 32 are mounted inboard of their supporting channels 30-30 and thus are disposed vertically beneath the level of the overhanging sideportions of the top cover, as see FIG. 8. Although the top plate member 27 of the cover assembly parallels the inclined plane of the roller wheel tracks 24-24 while the bottom frame member 29 of the cover assembly parallels the horizontal top plane of the open top of the hopper, it will be apparent that as the cover shifts by gravity along said tracks forwardly into its hopper closing position, the bottom frame member 29 of the cover assembly will shift horizontally from a position spaced freely above the horizontal plane of the open top of the hopper into a lowered position in which it rests upon the top edges of the hopper to close the same. Thus, there is eliminated to maximum degree any possibility for the cover to scrape along the top of the hopper as it shifts into its hopper closing position. Instead, the cover is gradually lowered toward the horizontal plane of the hopper top and to more effectively seal it closed against the hopper top the undersurface of the bottom frame member of the cover is provided with a cushioning seal or gasket 33 of asbestos or other suitable gasketing material.

It will be noted that the fore ends of the wheel track flanges 25-25 are each downturned, as at 34, to provide cam surfaces for lowering the front wheels of the hopper cover 18 to insure that the front end of said cover effectively sealingly engages the front top edge of the hopper and for raising the front wheels to quickly break the seal between the front ends of the hopper and the cover when the latter is shifted rearwardly out of its sealing engagement with the hopper and into its fully opened position. Also, these downturned front end portions 34-34 of the wheel track flanges supplemented by front wheel stops 34a, serve as detents to hold the gate or cover 19 in its fully closed position.

'Extending upwardly and rearwardly behind the rear wall of the hopper 13 are a pair of transversely spaced sharply inclined tracks 35-35 having wheel-engaging flanges 36-36 which respectively merge with the hereinbefore described wheel-engaging flanges 25 of the tracks 24-24. These rear tracks 35-35 are of a length sufficient to permit the rear wheels 32-32 of the gate 18 to move upwardly therealong into a position, as shown in FIG. 3, in which the gate is completely out of covering relation with respect to the hopper and with the front wheels 31-31 of the gate resting upon the rearmost portions 37-37 of the tracks 24-24. Any suitable means may be employed to support the rear upwardly inclined tracks 35-35 in rigidly fixed relation to the tracks 24-24, such as the supporting struts and braces shown in FIGS. 2 and 3, so that the wheel-engaging flanges of the track 35-35 extend continuously in sharply angled'relation to the wheel-engaging flanges 25-25 of the side tracks 24-24.

Suitably supported at the top ends of the upwardly inclined rear tracks 35-35 and extending transversely therebetween is a rigidly secured frame structure 38 for supporting a revoluble shaft 39 having its opposite ends suitably journaled in bearings 40-40. Keyed to opposite end portions of this shaft are a pair of winches 41-41 for cables 42-42 which have their free ends respectively secured to transversely spaced points along the rear end of the gate 18. The revoluble shaft 39'is suitably geared, as by the gear train 43, to an electrically operated hoisting motor 44, of any conventional reversible type having coupled thereto an electrically energizable magnetic brake, as for example the DC magnetic shoe brake illustrated in catalog sheet [I6 l .48 of the Beaumont Birch Company, Philadelphia,

Pennsylvania, the motor being operable to drive the shaft 39 for winding the cables 42-42 on their winches and thus draw the hopper gate from its closed position shown in FIG. 2 into its open position shown in FIG. 3, in which latter position the coverjis' held by the brake coupled to the motor. When it is desired'to seal the hopper closed, the brake is deactivated to permit the cover to descend by gravity under the influence of its own weight downwardly along the sharply inclined rear tracks '35-35 and along the side tracks 24-24 to its fully closed position shown in FIG. 2.

Hoisting and lowering of the cover 18 is controlled by suitable limit switches connected in circuit with the electrichoisting motor 44, each having its own control contact. Thus, as shown in FIGS. 2 and 3, a limit switch 45 controlled by contactor 4'6 carried by the cover is provided at the front end of one of" the side rails 24a-24a for interrupting the current supply to the hoisting motor when the gate is moved into its closed fposition. For operating the motor to raise the cover to its fully opened position a motor control limit switch contactor 47 is provided at the rear end of the cover for engagement with and actuation of a limit switch 48 mounted upon the upper end of the rear track 35 to stop the motor and activate the brake for holding the cover in its raised position. Upon deactivation of the brake, the latter releases its hold upon the cover and so permits it to be lowered by gravity under control. of the motor into its hopper-closing position. It will be un derstood, of course, that any suitably coupled motor and brake mechanism and electrical circuitry may be employed for effecting opening movement of the hopper cover by operation of, a hoisting motor acting upon winches and cables as above-described for holding the cover in its open position and for permitting gravity return of the cover into its hopper-closing position.

FIGS. 12 to 18 illustrated certain modifications of the construction of the apparatus as hereinbefore described. In this modified construction, the rearmost pair of roller wheels 32a-32a on the cover 18a are mounted upon the top of the cover as best shown in FIG. 12 for riding up along the sharply inclinedrear track members 35a-35a during raising of the cover into its opened position. These rear tracks 35a-35a are, however, respectively provided with upwardly extending auxiliary tracks 49-49 to form continuations of the rear tracks 350-3511 along which the rear roller wheels may ride for elevating the cover 18a to a height greater than that permissible by the track arrangement of FIGS. 2 to 11.

By so providing for increased lift of the hopper cover into its position best shown in FIG. 14, with the front wheels 31a- 31a of the cover resting upon the rear tracks 35a-35a and the rear wheels 32a-32a resting upon the auxiliary tracks, adequate space is provided between the lower (front) end of the cover and the incinerator hopper for access to the hopper and other closely associated parts of the apparatus for such cleaning and servicing thereof as may be required.

The hoisting motor and its associated cable winches are mounted in this modified arrangement at the base of the rear tracks 3 5a-35a with the cables 50-50 for the winches extending upwardly and trained around elevated idler pulleys 51-5l .and thence downwardly to and along the bottom of the coverto cable securing points 52-52 located at the front end of the cover, as see FIGS. 12 and 14.

As in the previously described construction of the apparatus, a limit switch 48a is mounted upon one of the rear tracks 35a-35a for limiting rearward movement of the cover 19a into its normally open position shown in FIG. 13. However, in :addition to this limit switch 480, a limit switch 53 is mounted upon the upwardly extending auxiliary track 49 for actuation by the contact 47a when the rear wheels of the cover enter upon the auxiliary tracks 49-49 for extra high lifting of the cover. Otherwise operation of this modified construction of the apparatus is substantially similar to that previously described for the construction of FIGS. 2 to 1 l.

As a safety precaution against unintentional or accidental lowering of the cover from its extra-elevated position shown in FIG. 14, a detachable safety chain 54 may be connected between the front end of the cover 180 and the supporting structure for the inclined rear tracks, which chain is of a length sufficient to hold the cover in its extra-elevated position should the magnetic brake of the hoisting motor release its hold upon the cover.

As an alternate safety precaution for holding the cover against accidental release from its extra-elevated position, in lieu of the above-mentioned chain there may be employed the counterweighted detent mechanism shown in FIG. 22. This mechanism includes a detent 55 pivoted as at 56 to a suitably fixed supporting strut or beam 57, which detent is provided with a laterally extending arm 58 adapted normally to project across the path of the front roller wheel of the cover. A counterweight 59 keyed through the shaft of the detent to the detent itself operates to swing the detent into its FIG. 22 position in interfering relation to downward movement of the wheel engaging the detent. When this wheel is below the detent, as when the cover is in the course of being raised, upon upward movement of the cover, its front wheel 31a engages the beveled surface 60 of the detent and cams the latter upwardly and out of the path of upward travel of the wheel against the restraints of the counterweight 59. Once the wheel passes upwardly beyond the detent, the counterweight 59 acts to return the detent to its FIG. 22 position to thereby present its arm 58 in position to prevent unintentional downward movement of the cover. Any suitable means may be employed for operating the detent.

If desired, the cover may be raised into its elevated open position by the use of a counterweight arrangement as shown in phantom in FIG. 12. In such arrangement a counterweight 61 guided for movement in a vertically extending track 62 is connected by a cable 63 to the rear end of the cover with the cable trained over a pulley or sheave 64 suitably journaled for rotation at a fixed point spaced above the uppermost reach of the cover. Also trained about a second pulley or sheave 64a is a second cable 63a connecting said counterweight 61 to the winch of the hoisting motor. Upon descent of the counterweight under control of the hoisting motor, the cover is raised into its open position, while upon lifting of the counterweight under power of the hoisting motor, the cover returns by gravity to its closed position. Thus, the counterweight, of suitable weight relatively to that of the cover, may provide a more controlled slower return by gravity of the cover into its hopperclosing position.

This counterbalancing system is particularly useful for control of the cover 19 employed as a closure gate for the auxiliary exhaust port illustrated in FIG. 1 wherein it will be observed that the counterweight in this instance is of a weight sufficient when released to raise the closure gate to its exhaust port opening position, the counterweight being held in its raised gate-closed position by a spring-loaded electromagnetically operated latch 65. Should there be a failure of electric power rendering inoperative the exhaust blower l and thus requiring opening of the exhaust port 17, the bolt 66 of the deenergized electromagnetic latch will be automatically retracted by its spring-loaded spring, thereby allowing the counterweight to descent and automatically raise the gate into its open position.

Reverting to the cover for the hopper, it will be noted that although the cover front roller wheels and the tracks therefor running along opposite sides of the hopper are more or less protected against debris accumulating thereon during loading of the hopper by overhanging opposite side portions of the cover (as see FIG. 4), it is nevertheless desirable to provide the hopper with side covers 67 as shown in FIGS. 19 to 21 which serve not only as shields for the side tracks on which the front wheels of the hopper cover travel but also as effective means for deflecting rubbish spilled over the opposite side top edges of the hopper into pits (not shown) extending along the sides of the incinerator. Since these side covers or deflecting shields 67 must be swung open to permit movement of the hopper cover from its closed into its open position, they are each hinged as at 68 to permit them to be swung outwardly from the full line position into the dotted line position shown in FIG. 19.

While this swinging open of the side covers or shields 67 may be effected manually by a person climbing up onto the roof of the incinerator, this may not always be possible or safe, particularly should there be a fire in the hopper. Accordingly, mechanism is provided for remote control of the operation of the side covers or shields, which mechanism consists, as shown in FIG. 19, ofa remote controlled double-acting fluid pressure cylinder 69 having its closed end pivotally connected, as at 70, to a sidewall ofthe hopper 19 and the free end of its piston rod 71 pivotally connected, as at 72, to the swingably mounted side cover or shield.

Each of these side covers or shields 67 may be fabricated of one or more sheet metal panels (three being shown in FIG. 20 and 21) rigidified and strengthened by horizontally extending structural members 73 welded or otherwise secured to its inner surface.

Whenever the hopper cover is closed, the cylinders 69-69 are activated to retract their piston rods and so swing the side covers on shields about their hinges into their closed positions as shown in full line in FIG. 19. Whenever it becomes necessary to shift the hopper cover out of hopper-closing position, the cylinders are then actuated to extend their piston rods, thereby swinging the side shields open.

It will be understood that the present invention is susceptible of various changes and modifications in addition to those hereinbefore described without departing from the general principles and spirit of the invention and it is accordingly intended to claim the same broadly as well as specifically as indicated by the appended claims.

What is claimed as new and useful is:

1. A cutoff gate of the character described for use in an incinerator comprising, in combination, a member having a perimetrally continuous planar top edge defining a passage therethrough, a gate shiftable onto and off of said member to selectively open and close said passage, a pair of transversely spaced parallel side rails respectively disposed on opposite sides of and in straddling relation to said member, said rails being disposed in an inclined plane spaced below the plane of said passage top edge and extending upwardly from the front end of said member to points just beyond the rear end thereof, at least one pair of roller wheels journaled on said gate at the fore end thereof adapted respectively to ride along said rails, power-operated means for shifting said gate along said inclined rails into a gate-open position in which said gate is disposed in generally upstanding relation with respect to the inclined plane of said side rails, and means operative to return said gate by gravity along said rails into a position in which said gate is seated upon said top edge of said member to hermetically seal said passage closed.

2. A cutoff gate as defined in claim 1 wherein said top edge defines the open top of a hopper for introducing successive charges of rubbish to be burned into an incinerator.

3. A cutoff gate as defined in claim 1 wherein said passage constitutes an exhaust port in the roof of an incinerator for venting to atmosphere the gases of combustion present in the furnace chamber of the incinerator.

4. A cutoff gate as defined in claim 1 wherein said gate is in the form of a rigid assembly adapted to completely embrace and be seated flatwise upon said top edge of said member to hermetically seal said passage closed and wherein an auxiliary set of rails is provided in rearward extension of said first-mentioned pair of inclined rails, said auxiliary rails being each sharply inclined upwardly and rearwardly with respect to said first-mentioned rails and of a length sufiicient to receive said gate thereon in upwardly inclined relation to the rear top edge of said member.

5. A cutoff gate as defined in claim 4 wherein said top edge defines the open top of a hopper for charging rubbish to be burned in an incinerator, said hopper having an inclined rear wall with respect to which said gate forms an upward extension when positioned upon said auxiliary set of rails to serve as a means for deflecting back into the open hopper rubbish which would otherwise spill over the rear top edge of said hopper.

6. A cutoff gate as defined in claim 4 wherein said gate is provided at opposite sides thereof with front and rear roller wheels adapted to travel along said first-mentioned inclined rails, said front and rear roller wheels being spaced apart fore and aft of the gate a distance such that they both rest on said first-mentioned inclined tracks when the gate is in position to seal closed said passage.

7. A cutoff gate as defined in claim 6 wherein said auxiliary rails are so relatively disposed in continuation of said firstmentioned rails that when said gate is shifted onto said auxiliary rails into its said relatively upright position the rear roller wheels of the gate rest on said auxiliary rails while the front wheels thereof rest on said first-mentioned pair of rails.

8. A cutoff gate as defined in claim 7 wherein said auxiliary rails are each provided with an upward extension thereof to permit said gate to be shifted upwardly along said auxiliary rails into an extra-elevated gate-opened position in which both the front and rear rollers of the gate rest on said auxiliary rails with the front end of the gate raised in spaced relation to the plane of said first-mentioned rails to provide servicing access to the passage and its associated gate and rails.

9. A cutoff gate as defined in claim 8 wherein said gate is provided with means for holding it in its said extra-elevated servicing position against accidental or unintentional return movement downwardly along its supporting rails.

10. A cutoff gate as defined in claim 9 wherein said lastmentioned means comprises a detachable chain extending between the gate and a fixed point located adjacent the lower end of the raised gate.

11. A cutoff gate as defined in claim 8 wherein said lastmentioned means includes a detent pivotally mounted for oscillatory movement about a fixed axis and having a counterweighted arm which is freely swingable out of the path of travel of a front wheel of the gate upon its upward movement upwardly along said auxiliary rails and into intercepting relation to said front wheel upon downward movement of said gate from its extra-elevated position above said detent.

12. A cutoff gate as defined in claim 4 wherein said poweroperated means includes an electric motor-driven hoisting mechanism having cable winding drums and cables extending therefrom and secured to said gate for drawing the latter upwardly along said inclined rails into its said upstanding passage-opening position.

13. A cutoff gate as defined in claim 11 wherein said hoisting mechanism is mounted adjacent the top end of said auxiliary set of rails.

14. A cutoff gate as defined in claim 11 wherein said hoisting mechanism is mounted adjacent the base end of said auxiliary set of rails and the hoisting cables extend from said winding drum to said gate about sheaves elevated above said hoisting mechanism.

15. A cutoff gate as defined in claim 1 wherein the frontal extremities of said side rails are depressed to permit lowering of the front wheels of the gate below their normal plane of travel along the rails whereby to correspondingly lower the front end of the gate into seated engagement with the front top edge of the passage as the gate reaches the forward limit of its travel along said rails.

16. A cutofi gate as defined in claim 1 wherein the underside of said gate is marginally provided with a resilient gasket adapted to engage the top edges of said passage and hermetically seal the passage closed when the gate is shifted into its passage closing position.

17. A cutoff gate as defined in claim 1 wherein said gate is of such transverse dimension relatively to that of the top edge of said member as to provide overhanging side portions projecting laterally beyond the corresponding side edges of said member and wherein said side rails and the gate wheels riding thereon are respectively mounted inboard of the opposite overhanging side portions of the gate.

18 In an incinerator apparatus as defined in claim I wherein said member is an open-topped hopper for charging rubbish to be burned in an incinerator and wherein the opposite sides of said hopper are respectively provided with side covers swingable about parallel axes spaced below and outboard of said side rails whereby said side covers may be selectively swung inwardly toward the side walls of said hopper in covering relation to said side rails or outwardly of said sidewalls in noninterfering relation to movement of said gate along said side rails into its opened and closed positions.

19. An incinerator apparatus as defined in claim 18 including fluid-pressure means operative to effect swinging movement of said side covers into and out of their said rail covering positions.

20. In an incinerator apparatus as defined in claim 18 wherein said side covers when swung into covering position with respect to said side rails present their free ends in closely spaced relation to the top side edges of the hopper and extend downwardly and outwardly of said side edges of the hopper to serve as means for deflecting rubbish spilling over the sides of the hopper during charging of the hopper from being deposited upon said side rails.

21. In an apparatus as defined in claim 18 wherein said fluid-pressure means comprise pneumatically operated cylinders respectively interconnecting opposite sidewalls of the hopper to said side covers.

22. In an incinerator apparatus for burning refuse and the like having a charging hopper for successively receiving and introducing into the furnace chamber of the incinerator loads of rubbish to be burned and an exhaust stack having associated therewith an electric motor-driven blower for forced draft exhaust of the gases of combustion from said furnace chamber to atmosphere through said stack, the improvement comprising in combination an auxiliary gas exhaust vent provided in the roof of the incinerator for natural draft venting of gases from the incinerator furnace chamber, shiftable closure gates for said charging hopper and said auxiliary exhaust vent, a pair of inclined rails for each of said closure gates along which the same travel from closed positions in which they are respectively disposed flatwise over the tops of said charging hopper and exhaust vent to hermetically seal the same closed into open positions in which they are raised into upstanding relation to adjacent top edges of said hopper and exhaust vent, means operative to shift said exhaust vent closure gate along said rails into its open position means to permit gravity return of vent closure gate into its closed position, and means operative to restrain said gravity return of the exhaust vent closure gate automatically upon interruption of electric power for operation of said motor-driven blower.

23. In an incinerator apparatus as defined in claim 22 wherein said means for effecting opening of the exhaust vent closure gage includes counterweight means cable connected to said last-mentioned gate for mechanically drawing the same upwardly along said tracks into its open position.

24. in an incinerator apparatus as defined in claim 23 wherein is included an electromagnetically operated springloaded latch mechanism having a bolt which is operative upon electrical energization of said mechanism to intercept and prevent gate-opening movement of said counterweight, said bolt being automatically retractable upon electrical deenergization of said latch mechanism to permit gate-opening movement of said counterweight.

Claims

4. A cutoff gate as defined in claim 1 wherein said gate is in the form of a rigid assembly adapted to completely embrace and be seated flatwise upon said top edge of said member to hermetically seal said passage closed and wherein an auxiliary set of rails is provided in rearward extension of said first-mentioned pair of inclined rails, said auxiliary rails being each sharply inclined upwardly and rearwardly with respect to said first-mentioned rails and of a length sufficient to receive said gate thereon in upwardly inclined relation to the rear top edge of said member.

7. A cutoff gate as defined in claim 6 wherein said auxiliary rails are so relatively disposed in continuation of said first-mentioned rails that when said gate is shifted onto said auxiliary rails into its said relatively upright position the rear roller wheels of the gate rest on said auxiliary rails while the front wheels thereof rest on said first-mentioned pair of rails.

10. A cutoff gate as defined in claim 9 wherein said last-mentioned means comprises a detachable chain extending between the gate and a fixed point located adjacent the lower end of the raised gate.

11. A cutoff gate as defined in claim 8 wherein said last-mentioned means includes a detent pivotally mounted for oscillatory movement about a fixed axis and having a counterweighted arm which is freely swingable out of the path of travel of a front wheel of the gate upon its upward movement upwardly along said auxiliary rails and into intercepting relation to said front wheel upon downward movement of said gate from its extra-elevated position above said detent.

12. A cutoff gate as defined in claim 4 wherein said power-operated means includes an electric motor-driven hoisting mechanism having cable winding drums and cables extending therefrom and secured to said gate for drawing the latter upwardly along said inclined rails into its said upstanding passage-opening position.

16. A cutoff gate as defined in claim 1 wherein the underside of said gate is marginally provided with a resilient gasket adapted to engage the top edges of said passage and hermetically seal the passage closed when the gate is shifted into its passage closing position.

18. In an incinerator apparatus as defined in claim 1 wherein said member is an open-topped hopper for charging rubbish to be burned in an incinerator and wherein the opposite sides of said hopper are respectively provided with side covers swingable about parallel axes spaced below and outboard of said side rails whereby said side covers may be selectively swung inwardly toward the side walls of said hopper in covering relation to said side rails or outwardly of said sidewalls in noninterfering relation to movement of said gate along said side rails into its opened and closed positions.

24. In an incinerator apparatus as defined in claim 23 wherein is included an electromagnetically operated spring-loadeD latch mechanism having a bolt which is operative upon electrical energization of said mechanism to intercept and prevent gate-opening movement of said counterweight, said bolt being automatically retractable upon electrical deenergization of said latch mechanism to permit gate-opening movement of said counterweight.