US2662241A

US2662241A - Soot blower of the short-travel retracting type

Info

Publication number: US2662241A
Application number: US766183A
Authority: US
Inventors: Mart Le Roy S De
Original assignee: Diamond Power Specialty Corp
Current assignee: Diamond Power Specialty Corp
Priority date: 1947-08-05
Filing date: 1947-08-05
Publication date: 1953-12-15
Anticipated expiration: 1970-12-15

Description

Dec. 15, 1953 Filed Aug. 5, 1947 LE ROY s. DE MART 2,662,241

sooT BLOWER 0F THQ SHORT-TRAVEL RETRACTING TYPE 3 sheets-sheet 1 INVENToR. 25? Je/aff Dec. 15, 1953 LE ROY s. DE MART SOOT BLOWER OF THE SHORT-TRAVEL RETRACTING TYPE 3 Sheets-Sheet 2 Filed Aug. 5. 1947 IN VEN TOR. @Katy Fe/)721111.

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Dec. l5, 1953 LE ROY s, DE MART 2,662,241

sooT BLOWER oF THE: SHORT-TRAVEL RETRACTING TYPE Filed Aug. 5. 1947 3 Sheets-Sheetl 5 IN V EN TOR.

atented ec. l5,

sooT BLOWER F THE SHORT-TRAVEL: RETRACTING TYPE Le Roy S. De Mart, Detroit, Mich., assignor to Diamond Power Specialty Corporation, Detroit; Mich., a corporation of Ohio Application August 5, 1947, Serial No. 766,183

Claims.

This invention relates to soot blowers which are projected into the boiler during the blowing operation and are retracted to a protected position during the intervals between blowing operations.

The main objects of this invention are to provide a soot blower incorporating an improved retractable blower tube which is protected from dust and dirt particularly during its non-use between blowing operations; to provide asoot blower construction in which the tube carrying the cleaning fluid is very rigidly mounted and securely held during the blowing operation; to provide an improved soot blower construction in which leakage of the cleaning fluid during the blowing operation is held to a minimum; to provide a soot blower construction in which the various packings and packing glands are more readily accessible for adjustment and replacement than in presently known constructions; to provide a soot blower of the projecting and retracting tube type which is compact in overall size and which utilizes a standard part made in large production for its supporting frame and to provide a soot blower construction in which it is assured that the cleaning fluid control valve will not be opened until the cleaning nozzle is in a fully projected position.

The present invention constitutes a further development of that disclosed in the copending application of Harry E. Brelsford, Serial No. 643,055, iiled January 24, 1946, now Patent No. 2,486,585, issued November 1, 1949, and assigned to the assignee hereof.

An illustrative embodiment of this invention is shown in the accompanying drawings in which,

Fig. 1 is a view partly in vertical longitudinal section and partly in side elevation, showing a blower head and associated mechanism constructed in accordance with the present invention, with the blower tube in retracted position and some of the parts broken away;

Fig. 2 is a view similar to Fig. 1 but showing, the position of the parts when the blower tube is in fully extended position;

Fig. 3 is a fragmentary transverse vertical sectional view taken substantially on the line 3--3 of Fig. 1 and looking in the direction indicated by the arrows;

Fig. 4 is a thin sectional detail taken substantially on the line 4-4 of Fig. 3 and looking in the direction indicated by the arrows;

Fig. 5 is a perspective view of the latch piece;'\ and Fig. 6 is a fragmentary longitudinal sectional view of a modied construction.

In the construction shown in Figs. 1-5 of the drawings, a supporting frame for the structure comprises a gooseneck casting generally designated 4 which also serves as a fluid inlet conduit and which extends upwardly from an annular 2 fiange 6 by which the structure is bolted to a pipe or other source of cleaning fluid.

A bracket 8 is secured by cap screws I0 to the casting 4 and extends upwardly and terminates ina vertically disposed annular head I2 which is in spaced horizontal alignment with the upper end of the gooseneck 4. The structure is tied together with great rigidity by means of an integrally formed .bracket I4 extending angularly upwardly from the gooseneck 4 and a corresponding bracket I6 integrally formed on the head I2, the upper ends of which brackets are rigidly tied together by a horizontally disposed tie rod I8 having nuts 2i] and 22 threaded on opposite ends thereof. The rod I8 is reduced adjacent its ends to form suitable shoulders against which the upper ends of the brackets I4 and Iii are rigidly held by the

nuts

20 and 22 respectively.

The gooseneck 4 is of hollow construction to form a conduit 24 for cleaning fluid introduced thereinto through a valve seat 26 controlled by a valve 2S. Valve 28 is mounted on the lower end of valve stem 30 which is axially slidable through an exteriorly threaded valve guide' 32 which is mounted through the upper wall of the casing 4 in axial alignment with the valve seat 26. A restricting disc 34 is adjustably threaded on the lower end of the valve guide 32 for controlling the amount of cleaning fluid passing through the valve seat. 'Ihe upper end of the valve stein 30 is provided with a mushroom cap 36 in the usual manner against the underside of which bears the top end of a helical compression spring 38, the lower end of which bears against an out-.turned radial ange 40 integrally formed on an inverted cup 42 which houses a plurality of packings 44 for sealing the valve stem against ghe esctalpefof cleaning uid. The spring 33 perorms e unction of hol on its seat 26. ding the valve 28 closed The upper end of the gooseneck conduit 24 therethrough terminates ina aqallivcirli .zontally disposed socket 55, opening toward and in alignment with the axis of annular iange I2 of bracket 8 and this socket is counterbored to receive a pair of concentric tubes, the outer of which, 46, is sealed at its left end as viewed in Fig. 1 by packing 48 normally held compressed by packing gland 50 secured by bolts 52 positioned at diametrically opposite sides thereof. The inner end of the packing 48 abuts against a bearing sleeve 54 which journals the left-hand end of the outer tube 46 so as to permit both rotation and limited axial movement of the tubes The right-hand end of the tube 48, or inner endl as it is generally referred to, is journaled in a bearing sleeve 56 which is mounted in a sleeve 58 with a packing 60 compressed by packing gland 62 interposed between the sleeve 58 and the exterior surface of the tube 4B. The packing gland 62 is held by a plurality of threaded studs 64 havingnuts 56 `oiitlieir outeiedsand .bei'ng threadedl into" the axiar face bf a drive" gear s's which is mounted on the exterior surface of the sleeve 58 and secured against relative rotation with respect thereto by a key.x'1 ,0.

The sleeve 58 at its right-hand end is `rigidly secured as by welding to a driving nut '|2 hich Iis journaled in an anti-friction bearing' 14 tinted in a counterbored recess foriedo'oncntic the face of the annular head I2. A bearing taining plate 'I6 is secured against the outer face of the head I2 by a plurality of screws '1:3 having their heads countersunk in the plate 16 s'a'slt'o be flush with the outer-'surface thereof.

The nut.|2 is rotatably `andslidably ttedupon an inner tube '80', with which -it is 'thre a`.'de'dlyl fin- :terengaged by means' of ahelical key'84 interiorly .fastened to-and` proj ectinginwardly from theniii'. J2 and engaging in alhelic'al'groove 02' formed'in the exterior. surfaceof the' tube 80. The outer surface of .the inner tube |30` at diametricallypposte points isv provided with axially'extending keyways 85 and B8 for receiving'ke'ys 90 92,

respectively, which are passed thrcughslots (undesignated) formed in the inner `end 'of 'the outer ,tube 43 and rigidly secured thereto as by welding.

.The length o the .tube 4.6 is such that when the parts are in the positioning'shown in Fig. lfoi 'the drawings, tube 4.6 is in spaced relation to the nut .1.2, as shown at 94, .the space 94 determining the amount'of axial movement of the tube' 45m' its supporting sleeve bearings 54 and 55.4 The innertube 80 is held against turning with respec't'to tube 46 `by the key and slot connecting means `SIL-,36 and .e2-B8, while the tube 80 is longitudinally actuatable byturning the nut "i2, aswillfbe apparent. The right-hand end of the inner tube 80 is interiorly threaded .to receive one end of -exlteriorly threaded blower tube 95, the opposite 'or outer end of which isv provided with a 'blower nozzle .9,8 having a plurality of discharge orifices '|00 therein asis usual .in constructions of'vthis general character. Means are provided for rotating the-gear wheel 6MB, sleeve 5,8 and'nut .l2 fori projecting `and'ffresracting the innertube 80. The rotating means comprises a chain sprocket wheel '|02 journale'd on one end of .thetie rod|8 and having its hub lI 4 fast vwith respect to one end ofthe sleeve |00, ,the opposite end of which is connected to a fpinibn gpc whicumeshes withteeth no of a gear wheel .613. The pinion |08 isjournaled on the shaft "I8 at the end thereof opposite to the sprocket wheel |02 and the pinion and gear are partiallyv covered and protected by a housing cover I |2 in the usual manner. The outer tube 45 has a` radially extending mounting ange |,I4 rigidly secured thereon by abutting against a shoulder integrally formed on the exterior of the tube and secured by set screw I I@ which, in turn, issecured by set screw I |8,` the inner end of the screw I l5 b'eingfof'reduced 'diam'- eter and extending into a shallowsocket formed in the exterior surface of the tube 46 'in appro"- priately .spaced relation to the shoulder thereon against which the hub of the .flange ||4 abuts. 'I'he'ange |4 has a cam I20irigid1y secured thereto by one or more bolts as |22.' The cam is generally annular in shape with a portion thereof cut out as is usual in constructions of this character and @oaths .with and is adapted to fopjcrate the upper end of a trigger |24,V the lower endof which'is pivotally mounted by a pin |26 on vns the upper end of a bracket |28 which is integrally gforrnedontle'base portlonof'thecastingf. Triggerf'l24 near its/lower n'd is provided with an integrally formed lobe |30 which is adapted to Yrest upon cap 36 and force the same downward as fshownlin Fig.'3 and which is mounted on one end "of'a'boltI`42 The bolt |42 .is `horizontally and laxially slidable through the trigger |24, in which Jit'lis'supported by a bushing |4I. The end of Athe .bolt opposite tothe latch |40 `projects .from .the opposite face of the trigger and carries a helical compression spring |44 'one end of which abuts andgbears againstthe face of the trigger |24 and the other end of which bears against a washer adjustably secured .in an appropriate position by a nut andlock nut |46 which are ,threaded on'th/e end of the `bolt |42.

The latch I 40 is also yieldably urged clockwise, as viewed in Eig. A3, to the position shown in full lines inthat view,.by'a helical tension spring |49, one'end of which is anchored to a pin |50 rigidly mounted on the' side of the triggerl .|24 and the other end of which is secured to the .latch |40 at `point corresponding to the axis of an anchor Apin' |52 located inspaced relation to the axis of the bolt |42 so as to tend to rotate the latchl |40 -rinar clockwise direction as viewed` in Fig. 3 ybut permitting thesame to swing outwardly in anti- `clockwise direction against the action of. .the spIing'IAS. Pin |50 also serves as a stop to .limit f'clockwise rotation of latch |40.

The upper end of the trigger |24 is provided with a shoe |54 which is of slightly greater width .than the trigger |24` and which serves as a bearing forcontacting cam |20. It is to be noted that the. width of `,the shoe |54 and of the cam' |20 is such thai-...the shoe bears against the outer pel ripheral surface of .the cam` |20 at all times're- ,gardless lof 4the position of the cam and outer tube. In other words, the outer tube may be shifted to the right to the extent of the clearance space and theshoe |54 is maintained in bearing contact on the outer surface of the cam |20 as shown in Eig. 2 of the drawings. The left'endofthe inner tube 80 as viewed in Figs. land 2.0i the drawings is of reduced out'- slde diameter to form a shoulder against which abutsthe base leg of a combined packing follower and bearinglaof L-shaped cross section. I

The peripheral face of the vertical leg of the member] 58 slidably ts the inside diameter" of the outer tube 46 and its axial face wall abuts against a pluraltyof packing rings |60. The packing rings |60 are retained by an internally threaded ring |52 screwed' on i the exteriorly Ythreaded end ofv tube 8,0, and locked thereto by sijitablejmeans. The peripheral surface of the 'rn'g|62 also has a sliding t within the interior of the outer tube 46 and also serves as a bearing between the tubes.

In the operation of this device the chain sprocket |02 is rotated either manually or by a power motor thus imparting rotation to the pinion |08 through the sleeve |06. Pinion |08 meshes with and drives the gear wheel 63 which through the key 'i0 rotates the sleeve 58 and nut l2 which is journaled in the ball bearing 14. Rotation of the nut 12 causes, in accordance with the direction of its rotation, projection or retraction of the inner tube 80 by moving the same axially, as will be apparent. During such axial movement, tube 80 is prevented from turning by the keys 90 and 92 which prevent relative rotation between the inner tube 80 and the outer tube 46. The outer tube 46 is, in turn, restrained from rotation by engagement of the shoulder |34 of flange |4 against the stop |36, which is rigidly mounted on the side of trigger |24. As the tube 80 completes its projecting movement to the right preparatory to a blowing operation, the packing follower |58 engages the left ends of the keys 90 and 92 and thereupon shifts the keys, and the outer tube 46 to which the keys are at tached, axially to the right from the position shown in Fig'. 1 to the position shown in Fig. 2, whereupon the keys and the end of the outer tube 46 abut against the rotating nut l2. This shifting to the right carries the latch |40 to the right against the action of compression spring |44 (because latch |40 overlaps the boiler side of lug |34 on flange I4, which is fast upon outer tube 46, see Figs. 2 and 3). The amount of axial movement is such that the shoulder |34 of flange 4 is disengaged from the stop |38 on trigger |24, whereupon rotation of the outer tube 46 is permitted. Continued rotation resulting from. the continuing actuation of the chain wheel causes the toe portion |2| of cam |20 to swing the upper end of the trigger |24 outwardly and downwardly as indicated by the arrow |32 in Fig. 3, whereupon the lobe depresses the valve stem 30 thus opening the valve 28 by moving itfrom its seat 26 and permitting cleaning fluid to ilow through the conduit 24, tubes 46 and 60 into tube 96 and thus out of the nozzle 98 through the orifices |00. The stop |36 and the tooth |34 now lie in different planes and do not interfere with the aforesaid valve actuation. When the: lug |34 moves out from beneath latchpiece |48, spring |44 moves the latchpiece back to its normal position close to the trigger as shown in Fig. 1. Engagement of the packing follower |58 against the keys 90 and 92 also tends to cause' compression of the packing |60, thus eiecting a tight seal during the blowing operation and effectively preventing the cleaning fluid from escaping through the sliding joint between the inner and outer tubes, while by virtue of this arrangement it is not necessary to fit the packing so tightly as to impose undue friction, as would otherwise be necessary. The packing follower |58 also serves as a rigid support for the end of the inner tube S0 and the outer tube being well"- supported at its opposite ends in the bearing sleeves 54 and 56, the entire rotating structure is rigidly supported during the blowing operation. It will be understood that the operator may continue to turn the chain wheel in the same direction as long as desired to insure proper cleaning, and the cam |20 will open the valve for the predetermined portion of each revolution which its angular extent dictates.

'Upon reversal of the direction of rotation ot the chain and chain wheel, and so of the nut 12, for retracting the tube 80, the inner and outer tubes may rotate together with the inner tube remaining projected until, asA the toe portion |2| of the cam |20, turning clockwise as viewed in Fig. 3, clears the outer end of trigger shoe |54, the trigger again moves inwardly toward the tube axis to the position shown in Fig. 3. The lower end of the shoe |54 is provided with an abrupt or sharp portion |55 which at this time moves into the relieved or cut out portion of the camV and overlies a radially disposed heel portion |23 of the cam to block further clockwise rotation (as viewed in Fig. 3) of the cam and of the tubes 46, 60. Continued rotation of the sprocket and nut in the same (reverse) direction thereafter drives tube 30 in a return movement back into tube 46. As tube 80 completes its retracting movement, the ends of slots 8B, 88 engage keys 30, 92 and move them and the tube 46 to the left to its extreme position shown in Fig. 1. Tooth |34 may then project beside and overlap the side or the thinner web portion of latchpiece |46 farther from the boiler, as before, but it will be seen that if the sloping back (outer) face of the tooth engages the latchpiece during the counterrotation of the cam and flange assembly and before tube 46 has moved all the way to the left7 latchpiece |40 may swing out of the way, simply turning counterclockwise on its pivot pin |42 and stretching spring |49. The parts are thus restored to their initial positioning depicted in Figures l and 3.

1n the modified construction shown in Fig. 6

parts analogous to those already described are identied by like reference numerals distinguished by the addition of the letter A to each. In this construction the latchpiece |40 is eliminated and the return spring |44A which replaces the spring 44 is in the formof a helical compression spring encircling the outer tube 46A and. reacting at one extremity against the collar ISA. and at the other extremity against packing gland. 62A, a washer as 64A being interposed between-l the spring and gland. The gland is constantly urged by the spring against the packing material A.

The cam plate l |4A is provided with a radially project abutment portion |34A adapted to bear against a lug portion |36A carried by the trigger |24A, the tube assembly being thereby held against rotation when the outer tube is at the leftward extremity of its movement, as shown .in Fig. 6. It will be noted that the spring |44A 4constantly urges the parts to and yieldably maintains them in this position under normal conditions. When with the outer tube held against rotation in the manner indicated the actuating nut is turned to project the inner tube A, the action of the parts will correspond to that of the embodiment lirst described, and in like fashion, when the inner tube reaches the end of its movement, it pulls the outer tube to the right, Adisengaging the abutment |34A from the lug 436A, as the cam ||4A moves to the right with the outer tube 46A. Thereafter the two tubes may rotatein unison, as in the previous embodi-1 ment,v and the blowing action may take place `during the entire or any desired portion of the i; rotary movement of the fully projected tube assembly, as will be apparent.

When, with either of the above described embodiments, the actuating means is operated in the reverse direction to tend to retract the inner tube, the twov tubes may tend to rotate in unison,

of said projection for overcoming said yielding means and thereby releasing said shoulder and stop from engagement whereby said outer tube is free to rotate with said inner tube and means controlled by the rotation of said outer tube for introducing cleaning fluid to said conduit and tubes.

8. In a soot blower, a supporting frame including a conduit for cleaning fluid, a tube mounted on said frame for both rotative and axial movement, said tube communicating with said conduit, the exterior of said tube being provided with a helical groove forming a coarse thread, a nut surrounding said tube and threadably engaging said groove, said nut being journaled in a fixed axial position, an outer tube journalcd on said frame in position to surround and normally cover said threaded tube, said outer tube being mounted to have limited axial movement, a shoulder carried by said outer tube, a stop carried by said frame for engaging said shoulder to restrain said outer tube from rotation, keying means preventing rotation of the inner tube relative to the outer tube, yielding means for maintaining said shoulder and stop in engagement, means for rotating said nut to project said threaded tube axially from said outer tube, means responsive to movement of the inner tube to a final stage of said projection for moving said outer tube axially against the action of said yielding means and thereby releasing said shoulder and stop from engagement whereby said outer tube is free to rotate with said inner tube and means controlled by the rotation of said outer tube for introducing cleaning fluid to said conduit and tubes.

9. In a soot blower, a supporting frame, a nut axially fixed and rotatably mounted on said frame, an inner tube threaded through said nut, an outer tube journaled on said frame and surrounding said inner tube and having one end portion limitedly axially movable with relation to said nut, yielding means normally maintaining said outer tube in axially spaced relation to said nut, a key on one of said tubes axially slidable in a keyway in the other of said tubes, means restraining said tubes from rotating only when said outer tube is in such spaced relation to said nut, means for rotating said nut to project said inner tube from said outer tube, means responsive to movement of the inner tube to a iinal stage ci such projection for moving said outer tube axially against the action of said yielding means, such axial movement of said outer tube freeing said tubes for rotation and means for supplying cleaning uid to said tubes.

10. In a soot blower, in combination. with a supporting frame, a pair of telescopically intertted tubes, including a rotatable outer tube, an inner tube longitudinally slidable to project to greater or lesser extent with respect to the outer tube, a screw threaded portion carried by a part of the inner tube which is housed within the outer tube when said inner tube is fully retracted into the outer tube, a driving element engageable with said screw threaded portion to move said inner tube longitudinally with relation to the outer tube, latching means including a releasable latching element engageable with the outer tube, slidable keying means coacting with said latching means and interconnecting said tubes for preventing unwanted relative rotation of said outer tube and inner tube during longitudinal movement of the inner tube, and an abutment portion operatively connected to said latching element and engageable by said inner tube when the latter is moved to projected position to release said latching element and thereby to permit simultaneous rotation of both tubes.

l1. In a soot blower, in combination with a supporting frame, a pair of telescopically intertted tubes including a rotatable outer tube, an inner tube longitudinally slidable to project to a greater or lesser extent with respect to the outer tube, a screw-threaded portion carried by a part oi the inner tube which is housed within the outer tube when said inner tube is retracted into the outer tube, a driving element engageable with said screw-threaded portion to move said inner tube longitudinally with relation to the outer' tube, means including a releasable latching element engageable with the outer tube, slidable keying means interconnecting said tubes for preventing unwanted rotation of said outer tube and inner tube during longitudinal movement of the inner tube, an abutment portion operatively connected to said latching element and engageable by said inner tube when the latter is moved to projected position to release said latching element and thereby to permit simultaneous rotation of both tubes, said outer tube being limitedly longitudinally shiftable by the inner tube as the latter approaches fully projected position, said abutment portion being carried by said outer tube and the latching element being operatively connected to the outer tube whereby such longitudinal shifting movement of the outer tube may serve to actuate said latching element.

12. In combination with means as set forth in claim 1l, means for supplying cleaning uid to said inner tube, means for controlling the fluid supply including a valve, actuating means for said valve including a cam member carried by the outer tube and a follower member engageable by the cam operatively connected to the valve to actuate the latter, the cam and follower members being of sucient length axially of the tube so that such cam and follower may remain in engagement throughout the full range of longitudinal shifting movement of said outer tube.

13. In a soot blower, in combination with a supporting frame, a ipair of telescopically intertted tubes both of which are rotatably mounted in the frame and one of which is longitudinally slidable with respect to the other, means keying said tubes against unwanted rotation with respect to one another, nut and screw portions for moving one of said tubes longitudinally to project and. retract the same, the other of said tubes being held against unwanted longitudinalmovement, means for holding the tubes against unwantedY rotation including an abutment portion on the other of said tubes, a latching element engageable with the abutment portion, means responsive to longitudinal movement of the projectable tube for disengaging said latching element from the abutment, and spring means yieldably urging the latching element into blocking relation with respect to said abutment, said spring means working in a direction parallel to the direction of longitudinal movement of the projectable tube.

14. A soot blower construction as defined in claim 13 whereinsaid spring means comprises a helical spring surrounding the outer tube.

15. A soot blower construction as defined in claim 13 including means for supplying cleaning nuidto they inner tube, the outer tube being 11mitedly. longitudinally-,shiftable to actuate said latchingelementto-and from blocking relation,

aangaat l'li Said Spring meanflatllgupon. Said: Giltl: time to. rieldably-'Oppcsemovemcnt offthclutching` clementf-rom suoli blocking relation.

16. A soot, blowerfasfdefneddn; elaim 13;: includ-l ing means' for supplying cleaning. iluid toV the inner'y tube, aV valve for controlling the,` iiowA ofl such. fluid, actuating means-for the-valve including a cam movable concurrentlywithsaidjlatching element, and. a follower, said abutment being carriedby said follower.

1-7. A soot blower as; iefinedV in claim 13` in.- cluding-:means for supplyingcleaning fluid tothe inner tube, a. valve for controlling the flow of suoli uid, actuating mea-ns for the valve includingA a cam movable. concurrently with said latening element, and a, follower,--A said;springY means being carriedibysaid toilower.

18. Ascot blower as fdened-.in claim-13 including means for Supplyingcleanin'g; fluid tothe inner tube, a valve for controlling;` the; flow of such; fluid, actuating means for the` valve includ-- ing a cam` movable. concurrentlyI withsaid latching` element, andi a follower, and said spring` means beingcarried by said.t outer: tube;

, 19, A soot blower construction. as defined in claim l-3` inoludingmeans'for supplying cleaning fluid tothe inner tube. the outer tube. being limitedly longitudinally' shftable to actuate said latching element to.u andv trom: blocking relation, a valve for controlling. the ow of such` fluid, actuating means. for thev valve including a" cam, carried by and. shif-table-withthe outer tube, and a follower held. against such shifting movement. and engageable byf the? cam, said; latching element being carried bysaid, outer tube and saidl abutment being substantiallyl fixed against such longitudinal shifting movement and against rotation with. saidA outer tube.

20. A soot blower construction asdefined in claim 1-3 including means` forsupplying cleaning fluidv to the inner tube,4V the; outer tube being lim.- itedly longitudinally shiftable to, actuate said. latching element to andl from blocking relation,A a valve for controlling' the: flowof such fluid.. actuatingV means for the valve; including a cam carried by and shftable with the outer tubeand a follower held4 against Sllh shifting; movementY and, engageablebyv thefcaim said latching; element and said; spring means' being carried by said outer tube and saidabutment being;l substantially fixed against such longitudinalv shifting movement. and against. rotation with said outer' tube.

21.. A soot.l blower construction as defined in. claimr 131including means forsupplyingv cleaning: fluid. to the innertubc. the cuter tube being limitedly longitudinally shiiiable te. aotuate said latching element to and` from! blocking relation, a valve for controlling: the ilove of; such fluid, actuating means for the valve? including a cam carried by andY shiftablef with' the; outer tube, and a follower heldagainst such; shifting movement' and engageable bythe cani;4 said latching elemeirit.I being carried by' said; outer tube, said sp1-ingmeans being carried by the follower, and said abutment being. substantially fixed against such longitudinal shifting movement and against. rotation with said outer tube.

22. Ina soot blower,y asupporting frame, an outer tube rotatably mounted on.. said. frame, an inner tubev axially slidable within said outer tube, said tubes being non-rotatable. with respect to each other. means for moving; said inner tube axially to. proiect the Same trom said outer tube, means for restraining, said outer tube against. rotation. during the projection. or said moet tube..

responsive-tomovement of the inner tube tea iinal; stage of projection for releasingr said restraining; means. whereby,- botb tubes, mayA be rotated inunisommeans for supplying a cleaning fluid` to said` tubes, and external bearing means rotatably-supporting said outer tube near both extremities thereof.

23. In. a soot blower, a supporting frame, an outer tube rotatably mounted on said frame, said tube beingV mounted to have limited axial movement, an'. inner tube axially slidable within said outer tube, saidV tubes being keyed together for preventing. Vrelative rotation therebetween. meansfor moving said inner tube axially to project the same from said outer tube, means for restraining said outer tube-against rotation during the projectionl of the inner tube, means responsive tomovement of the inner tubefto a final stage of projection for moving said outer; tube4v axially.- and; thereby releasing said restraining means whereby both tubes may be rotated in unison, and external bearingr means rotatably supporting'said outer tubenear both extremities thereof.

24.- A soot blower as defined in claim l whereinsaidlatching means includes two elements, one

connected to the frame and the other to the outera tube'said-keyingy means being carried partly by the, inner tube and partly by the outer tube.

25. In a soot blower, in. combination with a supporting frame, a pair of telescopically interfitted` tubes, including an inner tube and an outer tube, the inner tube being longitudinally slidable with respect to the outer tube, means for sliding the inner tube toproject and retract the saine, means for supplying cleaning fluid to said inner tube, packing means for sealing the space between. saidL tubes, means for tightening said packingV meansagainst the exterior of the inner tube andthe interior of the outer tube in response to, projection. of the inner tube, including an abutment, portion` carried by said inner tube and movable to a position to, exert pressure upon said packing means: as the slidable tube reaches the projected position, said inner tube being slidable through asubstantial travel, the outer tube being also, limitedly slidable through a relatively slight travehan abutment portion carried by the outer tube, the packing means being interposed between said: abutment portions and compressible therebetween, when the inner tube is fully projected, springl mea-ns opposing` longitudinal movement of; the outer tube inthe direction of projecting; movement: of the, inner tube, wherebyl when tbe inner tube, is fully projected by said means for sliding the same the outer tube is also; longitudinallyy moved by force transmitted throughq said abutments and packing and the resistance. of the. spring means is also imposed upon the packing.

LE ROY S. DE MART.

References Cited in the -file of this patent UNlTED STATES PATENTS