US2493656A

US2493656A - Sequentially operated multiple

Info

Publication number: US2493656A
Authority: US
Publication date: 1950-01-03
Anticipated expiration: 1967-01-03

Description

Jan. 3, 1950 E. c. s. CLENCH SEQUENTIALLY OPERATED MULTIPLE BLOWER 5 Sheets-Sheet 1 Filed April 6, 1945 Jan. 3, 1950 E. c. s. CLENCH 2,493,656

SEQUENTIALLY OPERATED MULTIPLE BLOWER Filed April 6, 1945 5 Sheets-Sheet 2 mm mm 9 Jan. 3, 1950 E. c. s. CLENCH SEQUENTIALLY OPERATED MULTIPLE BLOWER Filed April 6', 1945 5 Sheets-Sheet 3 QR WNN N yak O O mm? Jan. 3, 1950 E. c. s. CLENCH SEQUENTIALLY OPERATED MULTIPLE BLOWER 5 Sheets-Sheet 4 Filed April 6, 1945 was 6mm NNN QNN 3 Jan. 3, 1950 E. c. s. CLENCH SEQUENTIALLY OPERATED MULTIPLE BLOWER 5 Sheets-Sheet 5 Filed April 6, 1945 Patented Jan. 3, 1950 ,stsc

SEQUENTIALLY OPERATED MULTIPLE BLOWER Edward Claude Shakespeare Clench, Leamington Spa, England, assignor to Automotive Products Company Limited, Leamington Spa, England Application April 6, 1945, Serial No. 586,946 In Great Britain January 7, 1944 16 Claims.

This invention relates to sequentially operated multiple blowers and has especial reference to hydraulically operated soot blower systems for boiler and like furnaces. The principles involved are, however, applicable to sequentially operated multiple blower systems used for other purposes.

It is the object of the invention to provide an improved form and construction of motor device for use in systems where a plurality of such devices are fed from a common source of pressure liquid and are desired to operate one after another in a predetermined sequence, each motor device being of the kind (hereinafter mentioned as the kind referred to) incorporating a changeover valve which conducts the supply of pressure liquid to the motor proper when the device is actually operating and thereafter to a bypass connection leading to the supply inlet of the changeover valve belonging to the next motor device in the sequence.

In a hydraulic remote control system having a motor device of the kind referred to, according to the invention the change-over valve is resiliently influenced to assume a position in which the liquid passes from the supply connection to the bypass connection. Preferably holding means act upon the change-over valve to retain the latter in its feed position in which it places the supply connection in communication with the hydraulic motor of the device, said holding means being automatically released when said hydraulic motor has moved a predetermined amount. The holding means conveniently comprises a member which is moved by the hydraulic motor in a direction substantially at right angles to the direction of valve movement, said member being arranged so that after a predetermined movement it frees the valve and permits the latter to be moved to its bypass position by a spring constituting the said resilient influence.

--According to a further feature of the invention there is provided for a soot-blower system, a hydraulically operated nozzle-actuating unit comprising nozzle-rotating mechanism, a hyt h',chanedraulic mo or driving sa1d mec amsm a g on the lme of Figure 2;

over valve which latter receives pressure liquid from the supply and in one position feeds it to the hydraulic motor, and in another'position delivers it to a bypass connection leaving the motor inoperative, spring means urging the'seleotor valve to its bypassing position, means for moving the valve to its feed position, and holding means which retain said valve member in saidfeed position and are actuated by the motor torelease the valve when the motor has moved a predetermined amount, thus allowing the spring means to move the change-over valve to its bypassing position. If desired, integrating mechanism, operated at each revolution of the nozzle, may control the holding means and cause the changeover valve to be released when the nozzle has made a predetermined number of revolutions. This integrating mechanism can conveniently comprise a holding member which is slidable at right angles to the direction of valve movement, and ratchet mechanism actuated by, or in commen with, the nozzle to move the said holding member, the latter being arranged to move to a position in which the change-over valve is freed when the nozzle has made a predetermined number of revolutions.

The improved form of motor unit is particularly suitable for operating the blower nozzles of soot blowers and the invention will therefore be described in this connection by way of example. Hydraulically operated soot blowers are, of course, well known and the nozzle devices fall into two classes, namely the non-retractable type and the retractable type. In the non-retractable type a nozzle fitted into the wall of the furnace is arranged, when operative, to inject steam or other cleaning fluid and at the same time merely rotate about its axis. '0n the other hand, in the retractable type of blower the nozzle is projected axially into the furnace immediately prior to the blowing operation and is then rotated while the blowing takes place, said nozzle subsequently being retracted to its original position, thus bringing the operation toa close.

The invention is illustrated by way of example in the accompanying drawings, in which:

Figure 1 is a fragmentary side elevation of a blower head of the retractable type, some of the internal parts being shown in dotted lines;

Figure 2 is a sectional elevation, drawn to an enlarged scale, showing the internal arrangement of the integrating mechanism and its associated valve device;

Figure 3 is a fragmentary sectional plan taken Figures 4, 5 and 6 are diagrammatic elevations showing parts of the integrating mechanism in various operative positions;

Figures 7 and 8 are views corresponding to Figure 3 and showing the masking plate in different positions, the sections being taken on the lines 1-! and 8-8 respectively of Figures 4 and 5;

Figure 9 is a sectional elevation of a modified form of integrating mechanism and valve device a hollow body In, through which extends a main 1- shaft ll carrying the blower no'zzleindicat'e'd at i2. The main shaft II is formed with a pair 'of flanges 13 and M, which are engaged by "a fork member l5 pivoted to the flood'y at 15. At its upper end the fork l5 has anafih "'11 connected to the piston rod 3 of a double-acting hydraulic piston and cylinder motor indicated generally at it, and shown more particularly in Figure 2. It has a piston l8 slidable in a cylinder which latter is pivotally connected at 2| to the body H3"; thus 'aIslth e p'iston" 'od PB isniov'ed to the left the fork 1'5 acts as'axl'eve'r, "causing the main "shaft 'l l 'ahd to slide aki'ally to the right. -The rnain' sha ft I and fiofizle l2 are rotated by outpu'tshaft n 'connectd by a pinion 24 and counte'rShaft gear I215, Z'B With a gear wheel 21 mounted-'upon aenvin sieeve '28, which is rotatable within the etey H]; but "is located against axiarmovement, The parts numbered 23 to 28 are-shownindottdflines ii l igure 1. The main shaft i l-hasfa st'ein portion 15179,- which is axially 'slida'ble withinithe-ariving-sieeve 28 but is connette therewithby splines or keys enabling a device es-arranged to rgaue'the-desired autoin'atic aCttiatiOn' oftli reciprocating motor i9 "and the rotary-motor-" 22;fsaid v'alv'e device -'bein g actuated by a holding device comprising eentrorniechanism 31. "For actuating this mechanism (which-will be escritfed'in'detail herein- -'after) the pistonrod l tis conriected by e link38 with enemies, the'-'spiridleof "which is indicated "at fill, said'spindle lll thusbeing'oscillated by the farm as as'theblower ziezzie lz'r'ec'iprocates. The gear wheel 2-! is -provided on its' right hand face adjacent its periphery-with a ea'm l l, which is adapted to ipu'sh a tappet l 'z towarcls the right, thus actuating an 'arii1'"43 and-causing a spindle All to b'e oscillated, "ori'c'e' for "each revolution of the blower nozzle Theparts'numbered 4'! to 44 arefshown in 'dofited lines in'Figure 1.

The internal 'constructioniof the valve device 3f5-and also the integrating mechanism 3'! are shownmore clearly in lligure 2; which also indicates diagrammatically the-connections 'to the various components -of "the external hydraulic control circuit. M i

I The valve ,device' 31,6 i s f ormed with two mutually parallel bores' 0 and5l containing respec- 'tively 'achange overpiston valvenie'mber52 and selector va1ve meri'ier?5'3 ,fthe latter also being of the piston :tyl el diuin o'fa tappet 32 and I serves to e n y'alve, member 52 t an annular working space 51 within the bore 58. At its middle part the bore has an enlarged space 58 communicating with a pressure liquid inlet connection 59, which latter is fed with pressure liquid from a pump 60 through the medium of apipe e l ,a-control valve 62 andapipe 63. The pump 66 'is of "course fed with liquid through a pipe as leading from a reservoir 65. The control valve 62 is also arranged to supply pressure liquid through a,pipe to a connection E'i leading pinto the annular working space 51; this operation is herein termed re-setting, the pressure liquid acting upon the valve member 52 and "tiuir'ed for the whole system, and is manually operated ior starting the blowing operation, and for res'etting all theintegrating mechanisms. The change-ever valve member-'52 is formed with 'fl/VQ circumferential grooves-68 and 59, which are respectively 'in permanent c orr'iiniinication with ports 'll} and T l and which

groovies

68 and 69 are adapted to communicate one at a time with the enlarged 'sp'ace5'8; 'th'u's placing the latter in communication with the port Tl when the valve ineinber 5'2 'is' in it'sileft ha nd -position, as shown, "and incommunicationwith the port '10 when the valve "member 52 is in its right-hand position. The port llllea'ds to a b'yp s's -connection l3 comprising a pipe whichlead's to the inlet connection (corresponding 'to59 ofthat'bIOW'er which is to 'beoperated next in'the sequence, i. e. which is required to operate "by-pressure liquid from the pump 63, when the 'p'resentfblower has made a compiste blowing operation. Theport H is constituted by the end-- of "a passage '14, the opposite end of the latter serving as a pressure inlet port 15 Torth'e selector valve member 53. The piston valve member 53 has at its right-hand end a "stem it of reduce'd diameter in order to provide in a manner 'sim il'arlto the valve member 52 that is, when permitted by the holding device 31 "thus bo'thvalve 'rrieiriliers are re-set (i. e. moved to the"le'ft-) simultaneously whenever pressure "liquid is fed to the connection 131.

The selector va lveineinber 53 "has a circumferentia'l groove 8'! WhlhfiS in permanent communication with the ressure inlet port '15, and y H V aunt pressure liquid through a radial passage 82;an airialpa'ssa'ge 83, and radial passages-84 to a narrow circumferential groove 85 adjacent thefierfihandiend 'of the valve member '53 This valvejinein-ber has three operative e9 n' 1and! aiffll f .r l i f s fir a position, thefgroovegfi -b lflg in register with a pe 86 ha in jqql iet 'o'e 1- In h central position fo f the valve frn'eiriber 53Ith'e groove 85 registers with a port "83 'ladinig to 'a connection 'the'valve member 53 is in its and pOSitIOII theqgroove '85 communicates t e-"nth with a port 9 ll l eading to a "connection 9 l. The reservoir SS isc upl'ed bya pipe SZ with a drain lconnection fl this'connection 93 has a transverse passage ll l leading to the

spaces

95 and 96 at the leftliand rentals or; lthe bores 35!) and 5| ectively, jwhile passage 31 connects the reservoir permanently with awide circumferential groove 98 formed in the valve member 53. It will be seen that when the groove 85 registers with any one or the three ports 86, 88 and 98, the other two ports are in free communication with the reservoir 65, either by way of the space 95 or the groove 98.

The connections 81 and SI lead by pipes 99 and I88 respectively to the corresponding working spaces WI and I82 of the reciprocating motor I9;

also the connection 89 leads by a pipe I83 to the inlet of the rotary motor 22, the exhaust from the latter being returned through a pipe I84 to the reservoir 65.

The operation of the valve device 35 is briefly as follows. With the valve members 52 and 53 in their re-set positions the by-pass valve member 52 being in its feed position as shown in Figure 2, the control valve 62 is operated to deliver pressure liquid through the pipe 63 and thence by way of the groove 69 to the feed passage 14, groove 8I,

passages

82, 83, 84, and groove 85 of the valve member 53; the pressure liquid therefore flows by means of the port 85, connection 81 and pipe 99 into the working space I8I of the reciprocating motor I9 (see Fig. 2) and causes the blower nozzle I2 to be advanced into the furnace by the action of the piston I8, rod I8 and lever I5, the liquid expelled from the working space I82 flowing by means of a pipe I88 and connection 9| through the port 98 into the groove 98 and thence back to the reservoir 65 by way of the

passages

91, 94, connection 93 and pipe 92. The advancing movement of the blower nozzle actuates the integrating mechanism 31, as will be hereinafter explained, thus causing the valve member 53 to assume its central position with "the groove 85 in register with the port 88. This causes the pressure liquid to be fed from the groove 85 through port 88, connection 89 and pipe working space I82 of the motor I9. This brings about retraction of the blower nozzle I2, and at the completion of this movement the integrating mechanism 31 frees the change-over valve member 52, thus enabling the latter to slide toits right-hand by-passing position under the action of the coiled spring 54. In its new position the groove 68 of the valve member 52 bypasses the pressure liquid from the connection 59, to the port I8 and the by-pass connection 13 leading to the next blower unit in the sequence; the groove 89 is, of course, isolated from the port 59 when the valve member 52 is in this right-hand position. As above mentioned, both of the valve members 52 and 53 are re-set to their left-hand positions when a fresh operation is required, by causing the control valve 62 to deliver pressure liquid into the connection 61 and thus into the two annular working spaces 51 and I1. This movement of the valve members 52 and 53 to the left also has the action of re-setting the in tegrating mechanism 31, as will be hereinafter explained, and said integrating mechanism acts to hold both valve members in their re-set positions in readiness for the next operation, which is, of course, brought about by feeding pressure liquid once again through the inlet pipe 63.

' tion of the cam 4i and tappet 42.

The integrating and holding mechanism 31 is also shown in Figure 2 and it comprises a casing II8 containing a valve-holding member in the form of a rack III, which is in the form of a somewhat rectangular flat plate having a pair of slots H2 and H3 by which the rack member III is mounted slidably, in a direction at right angles to the axes of the valves 52, '53, upon a pair of studs H4 and H5 carried by the casing 31; each of the slots has an inclined foot portion indicated at H211 and II3a respectively, acting as deflecting means, so that when the rack member III approaches its fully raised position it is deflected towards the right owing to the obliquity of the foot portions II2a and H311. The rack member III is urged downwards by a coiled tension spring I48 connected to the rack member at H5 and anchored to the casing H8 at II1. Along its right-hand edge the rack member III is formed with two sets of ratchet teeth indicated at H8 and H9 respectively. The ratchet teeth H8 are engageable by the upper extremity of a fiat pawl I28, which is pivoted at I2I to an arm I22, which arm I22 is freely rotatable upon a stud I23 carried by the casing H8; the arm I22 has a depending lug fitted with an adjustable stop screw I24 arranged to engage with a projection M5 on the casing II8, while a bracket I220, is mounted on, and extends upwardly from the arm I22, and is fitted with an adjustable thrust screw I25. The arm I22 is urged downwards by a coiled tension spring I26, while a tension spring I21 connects the lower end I28 of the pawl I28 with the stud I23, thus pressing said pawl towards the edge of the rack member III. The ratchet teeth I I9 are similarly engaged by a pawl I28 pivoted upon a pin I29 fixed to the extremity of an arm I38 and having its top end urged into engagement with the rack member I I I by a coiled tension spring I3I attached to the lower end I28 of the pawl I28. In this case, however, the arm I38 is attached to the spindle 44, which, it will be remembered, is oscillated by rotation of the blower nozzle owing to the ac- Thus for each revolution of the blower nozzle I2 the pawl I28 feeds the rack member III upwards through a distance corresponding to one or two of the teeth I19 (depending upon the design of the cam 4i and its associated mechanism). During such upward movement of the rack member III the pawl I28 acts as a detent. The arm I38 is provided with a stop screw I32 and is urged downwards by a coiled tension spring I33 having its upper end attached to the rear end of the pin I29.

It will be seen that the spindle 48, to which the arm 39 is secured, carries inside the casing H8 a pair of arms I34 and I35; the arm 534 is arranged to engage at its end with an adjustable thrust screw I38 mounted upon a bracket I31 forming part of the rack member III, while the arm I35 carries a pin I38 (shown in dotted lines) 'which is adapted to engage with the thrust screw I25 as the spindle 48 reaches the end of its movement in an anti-clockwise direction. Mounted behind the rack member III is a rectangular masking plate I39, which is pivoted to the casing H8 about a vertical axis I48, as is shown in Figure 3, the masking plate I39 being urged reanemone :i'ster when :the irack memberr l IiIfiS ini-lts lowernnhst position, as" shown in :Eig'u're .22, said cam rprojections 1A2 and I143 zthen: causing the masking platexlflsitorbe .pushedcbackwards'put of engagennent'with "the :pawlsi-I 2 "and'II 28. The left-hand iedge'i surface" 144 of *theirack 'member' I I I .is ar- Iangedtoengage..with'the stem portions 55 and 1610f :the piston valve members 52 and-.53 respecitivelyfsaid rack:member thus constituting a stop which holds and positions the valve members ,aagain'stmovement :by their corresponding springs "Hand 8! .At its lower .part the rack member .I-=I-I :is formed with a :step :Ma adapted to hold :the'va'lve member 53 in its central position.

The operation of the integrating mechanism will now be described with reference to Figures 7 '2 and-3 andto-the diagrams shown in Figures 4 to *8 inclusive. Figures 2-.and 3 show the positions :occupied-by the parts towards the commencement of .a blowing-operation, the nozzle I2 being nearly gatjtheend 'of itsiad-vancing -stroke, and thevalve n embers 52 ,and 53 in their left hand positions. -';l'. hi-s means that the ;.arm 39 ismoving angularly a clockwise -direction,bringing the arm I34 :into engagement with the thrust screw I36. The final part ofthe advancing stroke causesthe arm -I3'4 tolift the thrust s erew I36 and -rack member 1H I1 5 through a distance corresponding 'to ;one pi the teeth H8, H9. The selector valve member, 53- is then pushed to the j right by its spring-85 until-the stem I6 engages with the .step -.I Ig,;asis shown :in- Figure 4. The piston :valve member .5-3-is thenin its ;central position and-feeds-the pressure liquid to the rotary motor 22, by:means oi a-groove-85 connecting with the outlet 88, 85 -and pipe lim ior 'turning the blower nozzle .-I 2. At the completion of each revolution ;the ,arm =I -.is-moved upwards, .by the action Yof the cam 4I on the-pin-ez causing rotary move- ,ment of the spindle E4, "andprogressively raises thegraeklmember ;I IIuntil, after a predetermined n nnber of revplutions have been made, the step lsldr has moved upwards beyond the valve stem "16, as indicat'e'd inibroken lines .in Figure 4, thus enabling thespring 88 .to move the valve mem- E-b'er 153 to 'itslri-ght-hand position shown in Fig. 5. This cuts 'ofithe supply of "pressure liquid to the rotary motor 2.2 and tran'stefrs it through the con- .nectionhj to-the working'spac'e Ifl2,"so that the reciprocating motor 'I 9 acts to retract the blower ,n'o'zzi fiz. .The, arm 391 moved angularly in an jantieclockwise direotion, and as theblower nozzle I2 ,ai nproaehes .its fully r e t racted position, .the ISEQon the arm I3,5 reaohes the thrust screw 11 .559 fihatihe? arm .22} ,j eve -up ar sw jthepa'wl'lfio'raises the rack member I II through 1a distance corresponding to one ofthe teeth I I .8. ;During this final movement of the rack member f'II! the foot portions I I2q. and I I3a,,,are in en- ;gagementwith the studs, H4 and II5,, so that,

the upward movement of the .rack member III "is'accompan'ied by a substantial deflection thereof to the right, ,to .the release position shown "Fi r t e wa s f t o i su fic entt Tallow the changelovervalve member 52 to shift :under the action of the spring 55 to its right.-

hand position in which it bypasses pressure liquid from the pipe83 to the 'pipe I3 leading to the "nextblower unit in the sequence of operation.

"During the progressive rising movement of the,

lrack member I II: from the, position shown in 'E su're athe m sk ng p at 9 s s agains h sides ofthe pawls I 23 and ,I2-8,' a s is shown in F u e 7 butes the spring 1 is ela vel l h the masking plate does not impede the action of $aid' ipawls the-masking p1ate.-. I;3 9 rests-against the .pawls; of '-.cour se,- "owing 1130 the fact that the cam :ZDIOjECtlOIl I43 has :moved .out, 10f register with theicam projectiontlfl. The final move- -ment Ofgthfi rackmember III to the right, however, as it reaches the top of its zstrpke' caus'es fthe :pawlsiIZfl and I28 to .be carried beyond the 1 masking ,plate I39, as will be seen in Figure 8, thus-enabling the integrating mechanism to re- :set itself'when the valve members52 and 53 are :re;-s e t. Until that time, however, the .springs154 :a-nd =80, 'actingon the rack'member I II through the medium of the valve members, iretain said rack-member :Iiiin its elevated position owing 170 the obliquity of the foot portions HM and 1130,, thuspreventing the'spring 1 48 from pull- ;ing down the rack member I I I. It will be remembered that the valve members 52 and-53 are both' in; their right-hand-positions when the blowing 'aoperation has finished, and that they are Ire-set to their yleft hand positions by admitting pressure liquid through the pipe 66 to the work- .i-ng spaces 5? and I1. When the force of the asprings -.5I-andp8 fl is thus removed from the rack ,member I I I,the return spring, I4} is able to pull saidmemberdownwards, as is shown in Figure 6, movement tothe left taking place at the same time while the studs II l-and II5 are disposed the foot portions -I I 2a and I I-3a of the slots. -Dnring this movement the-pawls IZII and I28 rest again'st the edge ,of the masking plate I39 and do not therefore ,impede the downward movement or theteeth H8, I I9, As the rack member -;I-i I reaches its lowermost position the masking .p late 1 is deflected owing to the engagement of the camlpro-jections I IIZJ 3, thus enabling the gpawlsfiifi andIIQB }to rte-engage with the rack .member .I IlI as is shownin EigureB.

7 In cases where Iit may Joe, desirable to render any gpariticular blower 'unit inoperative, a stop -pin indicated -in' broken linesat I in Fig. 2 may be .provided inorcler tohold the rack memas; ;I. I I in its rally raised position; the pin I45 is mounted ,up on-;the end of: an arm I46, the 45 ,spi dle M] .of which-projects through the front ;of the casing -I=I;,I-end ng-provided with an :opcrating handle Iii? having two positions, namely a blower on} position corresponding to the lowered position of the pin I45, asshown in Figure 2, and a blower off position in which the pin -I -l5-holds the rack member III at the top of its stroke. s V v V Where the-blower unit is of the non-retractable typethe' reciprocating motor I9 is, of course, omitted and the valve device 3.6 can then 'be simplified =a convenient'arrangement is shown in :Figur'e 9," thewalve-being indicated at 36a and its integrating mechanism at :3'I'a. The valve 350; comprises 'a':chan'ge=over :piston valve mem- {her-"52a, which "is identical 'withthat shown "in Eigurel-"andwhich' is urged towards its" righthand or bypassing positionby'acoiled compre's isi'on"spring"54. The bore'filVahd its ports are "also arranged siniila'r'ly," but this cas e the 'port *tdwcommuriidates directly fwith"a imotor connection'jindicatied ah- 89a. This leadsto the "r'otary jihotbifl? "byyva or a pipe I eta, while the liq'uid senate byI's'-Cid ihotor 22 flows backto er'v'hr; byway of*a piige'TlMand the "whichdatter la dsfitothe drain con- "il wea -est. flnt he' int'graun necnanism it is" Monger n'cessaty 'to'ja'ctuate nie'aim "I22, 'so t at the 'pawl IE fife" r ie d' th'e'rebyhier'ly acts u are aaenetwpntsm aasa ardinevades of the rack member III while the lower pawl I28 is being actuated due to rotation of the cam 4| (Figure 1) and spindle 44. Re-setting of the valve member 52a is carried out as before by admitting pressure liquid to th annular working space 51 by way of the pipe 56, thus forcing the valve member 52a to the left against the action of the spring 54 and enabling the return spring I48 to pull the rack member III downwards to the position shown in Figure 9, the pawls I20 and I28 resting against the edge of the masking plate I39 until this position is assumed similar to the position shown in Figure 6.

When the pressure liquid is cut off from the resetting pipe line 56, the'rack member III retains the valve member 52a in its left-hand position, to start the next blowing operation when the control valve 62 is actuated to feed pressure liquid. from the pump 69 through the pipe 63 to the enlargement 58. The liquid then flows through the port Ha and connection 890. to the rotary motor 22, thus driving the blower nozzle I2 and causing the arm I36 to be oscillated so that the pawl I 28 feeds the rack member III progressively upwards. At the revolution before the last the foot portions H211 and lI3a reach the studs H4, H5, and therefore when the rack member III is further raised during th last revolution, said rack member moves to the right owing to the obliquity of the said foot portions, thus permitting th spring 54 to move the valve member 52 to its right-hand or bypass position.

This cuts ofi the supply of pressure liquid to the rotary motor 22 and diverts it through the pipe 13 to the next blower in the sequence. The integrating mechanism shown in Figure 9 resets itself automatically when the valve member 52 is being re-set, the action being the same as in the preceding example, with the masking plate I39 holding the pawls 26 and I28 away from the teeth H8, H9, until the rack member III reaches its lowermost position, at which point the said masking plate I39 is deflected by the projections I42, I43.

An alternative form of valve and integrating mechanism suitable for a blower head of the non-retractable type is shown in Figures 10 and 11, the valve being indicated at 561) and the integrating mechanism at 312). Disposed Within th bore 59 is a piston valve member 52b, which is formed at its right-hand end with a stem I54 screw-threaded into a yoke member I55 constituting part of the integrating mechanism 31b. The right-hand part I55a of the yoke member I55 is formed with a spigot I56 serving as a guide for a coiled compression spring 541), which latter abuts against a cap I51 and is arranged to urge the yoke member I55 and the piston valve member 521) towards the left. The valve 36?) is of the same general construction as the changeover valves described above, the valve member 521) having an annular groove 6% which is in permanent communication with the enlargement 58 of the bore '56, said enlargement being fed with pressure liquid through a pipe 63 by means of a pump 60 and control valve 62. When the valve member 521) is in its set position, as shown in Figure 10, the groove 6% enables the pressure liquid to flow through the connection 89b and pipe I93 to the rotary hydraulic motor 22. On the other hand when the valve member 52b is in its left-hand position, the enlargement 58 then communicates with a groove 68b arranged to conduct the pressure liquid to an outlet con nection 12b and a pipe 13 leading to the pressure inlet next in the sequence; at the same time the groove 6% connects the motor port 68b with a port I58 leading to the drain connection 93b and thence to the reservoir 65 by way of the pipe 92. To re-set the valve member 52b the control valve 62 is operated to deliver pressure liquid through the pipe 66 leading to the resetting connection 61 and a working space 5111 at the left-hand end of the bore 50. The pressure liquid then acts upon the end of the piston valve member 52b and urges it towards the right against the force exerted by the coiled compression spring 54b.

The integrating mechanism, which is arranged to hold the valve member 52b in the re-set posi tion, comprises a latch bar I59 of rectangular cross-section slidably fitting between the sides I60 and I6I of the yoke member I55 and supported by a tubular guide I62 extending from the casing Ilflb downwards within a bore I'B I formed in the latch bar I59. The tubular guide I62 and the bore I64 contain a coiled compression spring 165, which acts to urge the latch bar I59 downwards, while a pad I66 rigidly secured to the casing H ll) by bolts I61 serves to support the latch bar I59 against movement towards the left on account of the force of the spring 54b. At its lower part the latch bar I59 is reduced in width to form a step I68, the arrangement being such that when the latch bar is in its lowered position, as shown in Figure 10, it effectively holds upper surface I10 of the part I55a, then the yoke member I55 and the valve member 52b can both move to their left-hand positions under the influence of the spring 54b. In order to bring about this rising movement a rocker I361) mounted upon the spindle 44b is urged in an anti-clockwise direction by a spring I33b and is fitted with a driving pawl I2Bb, which latter is urged towards the latch bar I59 by a spring (not shown). At its upper part the latch bar I59 is formed with a series of wide ratchet teeth 91), which are engaged by the driving pawl I281) and also by a detent pawl I26b, the latter being pivoted to the casing I Iilb at HI and also being urged towards the latch bar I59 by a spring (not shown). The pawls I20?) and I28b are sufficiently wide and are so mounted that they extend beyond the edges of the latch bar I59, as is shown in Figure 11, the protruding parts being disposed in line with projections I12 and I13 formed upon the sides I69 and I6I of the yoke member I; the

projections I12 and I13 are, however, normally out of engagement with the pawls, even when the yoke member I55 is in its re-set position, shown in Figures 10 and 11.

At its lower part the casing IIIlb is provided with a spindle I41b carrying an arm I46b, the free end of which is in engagement with the bottom of the latch bar I59, so that angular movement of the spindle M11) in a clockwise direction acts to raise the latch bar I59. The spindle I411) projects through the frontof the casing III! and is provided with an angularly movable handle (not shown) adapted to be positively located in any one of a predetermined number of angular positions within its range, each position corresponding to a predetermined number of revolutions of the blower nozzle.

When the device is in its re-set position, as shown, and pressure liquid is fed by the control valve 62' to the pressure inlet connection 63 to 2,49331: so I drive the rotary motor- 2 2,'-the spind1e 44b is -oscillated by thecam 4| (asdescribed with reference to-Figure l)-oncefor each revolution, the clock wise angular movement of the rocker I30b actuatingthe pawl IZBb so thatit lifts the latch bar I59-by 'an amount corresponding to one of the teeth 'I l 9b.' During the return movement of the rocker 1353b the latch bar I59 is sustained by the detent I292). In this way, as the rotation of the blower nozzle I2 proceeds, the latch bar I59 reaches the position where the surface I69 rises beyond thesurface I'IIl, thus allowing the spring 54b to move the yoke member I55 to the left, thelpa'rt i550; engaging the step I68 and the valve member 525 being moved to its by passing position, This of course-diverts the pressure "liquid tothe next blower in the sequence and the blower nozzle 12 comes toa standstill The number of revolutions which are necessary to bring thelatch bar; I59 to its fully raised-position depend, of course, upon its initialheight and this can readily To re-set the 'de'vice, pressure liquid-is admitted to the wor kingspace-51b as-described above, thus moving the valve member 52b'and'yoke member l55 to the right against the force of the spring 5.459 These parts-move beyond the position shown in -Figure 1, thus enabling the projections I12 and I 'i3 to bear against the pawl I 28b and detent' locoana move them=out of engagement'with the teeth 9b? The-latch'bar I5'9 is'therefore retliatth'e latter canraise th'e latch bar I59 when the 'motor 22 is next operated! It is to be observed that' the arrangements whiehhave been described "are given merely by way of example and-that various modification's may be made :in the construction and arrangement of the parts; also that the invention-isnot limited tosootblower systems, as the'hydrauli'cmotor units can obviouslylbe employed for other purposes.

What I claim is:

1'. Fora soot-blower system; a hydraulically operated nozzle-actuating unit, comprising nozzle rotating mechanism, a: hydraulic motor driving;

said-"mechanism, a change-over valve, a by-pass connectiontherefrom the change-over valve receiving pressure liquid fromthe supply and in one position feeding-it to the motor and in another position delivering it to the by-pass connection leavingth'e hydraulic motor'inoperative, a spring: urging the change-over valve at alltimes to its by-passin'gposition, valve operating means for moving the change-over valve against. the. spring force to its feed-position, and aiholding device for retaining" the change-over valve in said feedpositionysaid holding device comprising .a holding member slidable acrossthe direction of valve movement.- andformed with a surface which controls the change-over valve; and" integrating: mechanism which connects the nozzle with-the holdingmember and moves saidlholding member's at'each revolution ofthe nozzleunit; until :a posi-: tion is reached where theholding: member res- {leases the change-over valve :and allows ithe'r s spring to move the change-over valve toits by:-"

pass position.

2. For a soot-blower system;'a hydraulically operated nozzle-actuating unit, comprising nozzle-1i rotating mechanism, a hydraulic motor drivinga said mechanism; a change-over. valve,-a by-"pass connection therefrom,the change-over valve re ceiving pressure liquid" from the supply and in one position feeding it to the motor and in another? position delivering it to therby-pass connection leaving the hydraulic motor inoperative, a spring;

urging the change-over valve at all timestonits' by-passing position, valve operating means for-1 moving the change-over valve against the. spring force to its feed position, andaholding device for retaining the change-over valve in said feed position, said holding device comprising a holding" member slidable across the direction-of valve" movement and formed with-a surface which controls the change-over 1 valve, ratchetfteeth; formed on the holding member, a. pawl oscillated;

by the rotation of the blower; nozzle and engaging;

said ratchet teeth, thereby progressively moving:

the holding member towards-a release positionin which said holding member is disposed free of the change-over valve to allowthe spring to-v move the change-over valve toits byepass position.

3. A nozzle-actuating unitaccording to claim 2," including pin and slotmec'hanism supporting theholding member, the slot havingra terminal portion disposed obliquely'sothat after reaching: a: predetermined position the: holding. member moves obliquely in a. direction" awayrfromxthe change-overvalve, therebyallowing the spring; to move the change-over valve-to its by-pass posi-i tion.

4. For a SODtr-blOWBI' system, a hydraulicallyoperated' nozzle-actuating-unit, comprisingznozzle rotating mechanism, a hydraulic motor'driving said mechanism, a change-over valve; a'by-pass connection therefrom, the change-over valve receiving pressure liquid from the supply and in one position feeding-it to themotor and in another position delivering it tothe by-passconnection leaving the hydraulic'motor inoperative, a spring urging the change-over valve atalltimes towards its by-passing position; valve re-setting means for moving the by-pass valve against thespring force to its feed position, holding means which retain said'valve member in said feed position and are actuated by the motor to release the valve-when the motor hasmoved a predetermined amount, thus allowing the spring means to move the change-over-valve to its by-passing position, and integrating mechanism, operated at each revolution of the nozzleto control the holding means and cause the'change-over valve to be released when the nozzl'e' has made a predetermined number of revolutions, the integrating mechanism and holding means including a; holding member comprising a raok plateformed with slots extendingparallel with an edge bywhich the'change-over valve is held, studs engaging said slots to guide the rack plate, ratchet teeth carried by said plate,- a pawl engaging said'teeth and oscillated by rotation of the nozzle, and deflecting'means'whereby' the final movement of the plate takes place laterally with respect to said' edge and frees the change-over valve.

5'. A nozzle-actuating unit according to claim 13 4, wherein the slots have foot portions inclined with respect to said edge and arranged to deflect the rack plate sideways as the foot portions of the slots engage the studs.

6. A nozzle-actuating unit according to claim 1, having spring means urging the holding member toward its normal position, and having in the change-over valve, a liquid pressure working chamber, to which pressure liquid is admitted to urge the change-over valve back to its normal position, thereby freeing the holding member and allowing the spring means to return the holding member back to its normal position.

7. A nozzle-actuating unit according to claim 4, wherein the integrating mechanism comprises a masking plate which is urged laterally against the pawl and holds the latter out of engagement with the ratchet teeth while the rack plate is being re-set, and a cam device which moves the masking plate away from the pawl as the rack plate reaches its re-set position.

8. A nozzle-actuating unit according to claim 4, wherein the integrating mechanism comprises a masking plate, a spring urging said masking plate laterally against the pawl and thus holding the pawl out of engagement with the ratchet teeth while the rack plate is being re-set, and a cam device comprising a pair of cam projections carried respectively by the masking plate and the rack plate, which cam projections come into register as the rack plate reaches its re-set position, and thus move the masking plate away from the pawl.

9. A nozzle-actuating unit according to claim 4, wherein the integrating mechanism comprises a masking plate, a spring urging said masking plate laterally against the pawl and thus holding the pawl out of engagement with the ratchet teeth while the rack plate is being re-set, a cam device which moves the masking plate away from the pawl as the rack plate reaches its re-set position, and a spring urging the rack plate to its re-set position.

10. A nozzle-actuating unit according to claim 4, wherein a first pawl engages the rack plate and is oscillated by rotation of the blower nozzle, and a second pawl, actuated by axial advance and retraction of the blower nozzle, also engages said rack plate, the first and second pawls both advancing the rack plate in the same direction.

11. A nozzle-actuating unit according to claim 4, having a selector valve which controls advancing and retracting movements of the blower nozzle as well as the rotation thereof, and is positioned by the rack plate.

12. A nozzle-actuating unit according to claim 4, having a selector valve which controls advancing and retracting movements of the blower nozzle as well as the rotation thereof, and is positioned by the rack plate, and a step formed on said rack plate for locating the selector valve in an intermediate position, in which it feeds with pressure liquid the motor which rotates the blower nozzle.

13. A nozzle-actuating unit according to claim 4, said hydraulic motor being a rotary motor for rotating the blower nozzle, said unit including also a selector valve which controls advancing and retracting movements of the blower nozzle as well as the rotation thereof, and is positioned by the rack plate, a step in the rack plate for locating the selector valve in an intermediate position in which said selector valve feeds the pressure liquid to the motor serving to rotate the blower nozzle, a spring urging the selector valve to a position in which it brings about retraction of the blower nozzle, and liquid pressure means which re-set the selector valve to its nozzle advancing position. 15 14. A nozzle-actuating unit according to claim 1, having a yoke member pressed by the spring of the change-over valve against the side of the holding member, said holding member being slidable relatively to the yoke member, and a step being formed in the holding member to enable the yoke member and the valve to move to the bypassing position when the holding member reaches a predetermined position.

15. A nozzle-actuating unit according to claim 1, having a yoke member pressed by the spring of the change-over valve against the side of the holding member, said holding member being slidable relatively to the yoke member, a step being formed in the holding member to enable the yoke member and the valve to move to the bypassing position when the holding member reaches a predetermined position, said unit also including ratchet and pawl mechanism which moves the holding member during rotation of the blower nozzle, the pawl being disengaged from the ratchet teeth by the yoke member when the latter is moved against the spring during the resetting of the change-over valve.

16. A nozzle-actuating unit according to claim 1, wherein a yoke member is pressed by the spring of the change-over valve against the side of the holding member, the latter being slidable relatively to the yoke member, a step being formed in the holding member to enable the yoke mem- 45 ber and the valve to move from a held position to the bypassing position when the holding member reaches a predetermined position, and wherein a tubular stem slidably carries the holding member, a coiled compression spring disposed within 50 the tubular stem urging the holding member towards its holding position.

EDWARD CLAUDE SHAKESPEARE CLENCH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 60 Number Name Date 1,979,136 Arey Oct. 30 1934 2,309,889 Eves Feb. 2, 1943 2,384,221 Waldie Sept. 4, 1945