A Machine for Cleaning Steam Boiler Flues.
Year: 1892

page_text: Date of Application, 28th June, 1892-Accepted, 26th Nov., 1892
DE BOLTIVATION.
A Machine for Cleaning Steam Boiler Flues.
1, PHILIP SCHUYLER KINGSLAND of No. 318 Chamber of Commerce
Building, Chicago, Cook County, State of Illinois, United States of America,
Mechanical Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
My machine relates to cleaning steam boiler flues, and the machine embodying
my invention is adapted to be placed at the front of a tubular steam boiler, and is
so constructed and arranged that, when once started, the scraper will be positively
forced through and positively withdrawn from each of the flues, one after the other
in successive order until all are scraped out.
I preferably use a chain composed of skeleton, hollow balls connected by jointed
links and driven by a sprocket wheel, whereby the chain is caused to operate the
scraper, positively pushing it through a flue and then positively withdrawing it
again through the same flue. A tubular guide is provided for the chain which
serves to direct the scraper to the proper flue as the carriage, upon which the chain
and guide are mounted, is brought into position.
The carriage must be moved horizontally back and forth in front of the rows of
flues, and must be lowered at the end of each row and the direction of its horizontal
movement reversed. Where the row below the row that has been cleaned contains
less flues, a diagonal downward movement must be imparted to the carriage in order
that it may come to rest opposite the first flue of the row having the lesser number.
Usually the cover of the hand hole comes between the flues of the last row as
illustrated herein. In such case, after the flues on one side of the cover have been
cleaned, it is necessary to pass up around the cover; therefore means must be
provided for hoisting the carriage.
These movements of the carriage must be made in proper relation, with respect
to time, to the operation of the chain so that the chain may be forced into and
withdrawn from the different flues, the carriage remaining at rest in front of each
Hue while the action of the chain in reciprocating the scraper is taking place.
I will now refer in a somewhat general way to certain of the more important
features of my apparatus as embodied in my machine.
FirstA pair of pinions driven in opposite directions are loosely mounted upon
a shaft, upon which a worm clutch is splined; lever mechanism for shifting this
clutch to engage first with one pinion and then with the other is provided. The
shaft is thus driven in one direction or the other, according to the engagement of
the clutch with one or the other of the loose pinions. This shaft is connected by
suitable gearing with the sprocket wheel which carries the chain, and, thus
change of the engagement of the clutch between the driven pinions, changes the
direction of the movement of the sprocket wheel carrying the chain and scraper.
Second After the scraper has thus been inserted in and withdrawn from a
flue, the carriage must be advanced a step to the next flue. This horizontal step
or movement is imparted to the carriage by a rack-bar, which being reciprocated
engages with one or the other of a pair of pawls provided upon the frame of
the carriage.
Third The pawls are separately pivoted, and their free ends or arms linked
together, and so arranged with respect to the rack that when one pawl is in
position to be taken by a notch of the rack, the other pawl will be drawn back
so as not to be engaged; thus the rack on being reciprocated will take a pawl
and so carry the carriage in one direction during one-half of its stroke, but will

page_text: •
not take the other pawl during the other half of its stroke. A weighted lever
in connection with a rotatable bar provided with pins for shifting said lever when
the direction of the carriage is to be reversed, is adapted to bear against the
free end of one of the pawls or that of the other as it is shifted to one side or to
the other of the carriage by coming against the pins upon the rotatable bar.
:
Fourth By means of a reciprocating sleeve carrying pins, provided upon one
end of the rotatable bar, the rack bar is prevented from simply exchanging pawls
to move the carriage back by the return stroke of the rack bar, and the carriage
is allowed to remain at its extreme position, in this instance to the right, until the
rack is again reciprocated.
Fifth A clutch connected with the vertically movable frame on which the
carriage is mounted is so arranged that the frame is lowered and raised as
required.
Sixth A clutch splined to the main shaft is adapted to engage with the hub
of the main driving wheel when the machine is brought into operation, and to be
automatically disengaged therefrom when the last flue has been cleansed, thus
throwing the machine out of action at the proper time.
:-
Seventh A ratchet wheel provided with notches about its periphery, and with
pins upon the side thereof, is combined with pawls, detents and levers in such
manner as to cause the different parts of the machine to operate in proper sequence
with respect to one another.
My invention will be more readily understood by reference to the accompanying
drawings, in which---
Fig. 1 is a front elevation of my automatic boiler flue scraper applied to the
front of a boiler, the doors of the smoke chamber being removed to expose the
front ends of the flues.
Fig. 2 is a detailed front view of the worm clutch, the ratchet wheel and levers
and rods combined therewith.
Fig. 3 is a plan view thereof.
Fig. 4 is a rear view of the machine, the carriage being removed.
Fig. 5 is a plan view of the rack bar with the attachment for reciprocating the
same together with the rotatable bar for changing the position of the pawls of the
carriage, as seen from line 5-5 of Fig. 4.
Fig. 6 is a plan of the clutch which acts to reciprocate the rack bar, and of
the clutch which acts to lower and raise the frame on which the carriage is
mounted.
Fig. 7 is a sectional plan upon line 7-7 of Fig. 1 with certain parts broken
away and removed.
Fig. 8 is a sectional view upon line 8-8 of Fig. 1 showing the worm clutch and
the pinions between which the clutch is placed, and the shaft geared to shaft upon
which the carriage is mounted.
Fig. 9 is a front view of the main ratchet wheel showing the pins upon the
front side thereof.
Fig. 10 is a front view of the same ratchet wheel, the pins upon the rear side
being indicated in dotted lines.
Fig. 11 is a detailed view of the shifting lever provided with a yoke, which
lever acts to shift the worm clutch to cause it to engage with the different
loose pinions.
Fig. 12 is a front view of the graduated indicator.
Fig. 13 is a detailed sectional view upon line 13-13 of Fig. 1, showing the
carriage carrying the sprocket wheel which drives the chain, and the weighted
lever in connection with the bar provided with pins for shifting the said weighted
lever to cause one or the other of the dogs of the carriage to engage with the
rack bar.
Fig. 14 is a plan view of the same on line 14-14 of Fig. 13.
Fig. 15 is a sectional view showing the clutch, the segment gear operated by
an eccentric provided thereon, and the bar provided with a pinion meshing with

page_text: the segment gear which is brought into ACTION DU
carriage.
the direction
DITC
Fig. 16 is a view of the portion of the clutch which is rigid upon the driving shaft.
Fig. 17 is a detailed sectional view showing the lowering and hoisting mechanism
on line 17-17 of Fig. 1.
Fig. 18 is a side view of the carriage in connection with the tubular guide.
The main driving wheel a in Fig. 1 is shown in engagement with the clutch al
which is splined to the shaft a². This shaft a² is provided with journal bearing a³
and the gear wheel a¹ meshing with the pinion a³ upon the shaft a and also meshing
with the teeth upon the wheel a'. The teeth of the clutch a and of the hub of
the driving wheel are V-shaped, and a spring a tends to hold the wheel a towards
the clutch. If, however, the shaft a should be prevented from turning under
moderate power from the driving wheel, the V-shaped teeth will cause the sprocket
wheel to be moved slightly on the shaft against the resistance of spring a³, and
the teeth passing over one another will make a noise to warn the attendant of the
obstruction. The bevel gear & engages with the pinions 12 between which is
placed the worm clutch b³. This clutch is splined to the shaft upon which the
pinions are loosely mounted and thus the direction of the revolution of the
shaft will be reversed as the engagement of the worm is shifted between
the clutches by moving the same longitudinally upon the shaft, as will be more
fully explained later.
The shaft is geared to the shaft b, which by suitable bevel gears 1º is connected
with the shaft which, as shown most clearly in Figs. 13 and 14, is connected
through the idler with the sprocket wheel which drives the chain. The
linkage between the shaft and the sprocket wheel of the form shown and
described, I have found very satisfactory. I however fully understand that this
linkage whereby the movement of the shaft , as it is controlled and driven first
in one direction then in the other, is transmitted and imparted to the sprocket
wheel and thence to the chain and scraper, might be varied according to the
circumstances and the judgment of the mechanic without departing from my
invention.
I have thus shown how the chain by power transmitted from the shaft is
inserted in and withdrawn from a fluc.
I will now describe the carriage which carries the chain longitudinally and the
vertically movable frame on which the carriage is mounted. This frame consists
essentially of the bars c c secured to the end pieces c³ ³, which are provided with
grooves corresponding to the upright guides e c. The carriage d is mounted upon
the bars cc', the bars serving as guides for the concave surfaces of the pieces d d²,
which are adapted to slide thereon, as shown most clearly in Fig. 13. The piece d³
is attached to the rack and moves therewith and is curved to make room for the
gear wheel upon the shaft . This curved piece d³ slides upon the bars c c', as
shown in Fig. 13. Mounted upon this carriage are the pawls d d separately
pivoted, and having their arms connected together by the link d. The weighted
pivoted shifting lever d' is mounted upon the bar d³ at the rear of the pawls and so
arranged that its shorter arm will press against the pawls dds to cause one or
the other of the same to project so as to be in the path of the rack, accordingly
as the weighted lever is in one position, or is moved upon said bar d³ to one side
or the other of the carriage.
As shown in Figure 14, the weighted lever d' is moved to the right of the carriage
so as to be opposite and press against the pawl d so as to bring the working end of
said pawl into the path of the rack do, while by means of the link the pawl d³
is drawn back so as to bring the working end of said pawl d back out of the path
of the notches of the rack io. The rack do is reciprocated to move the carriage
step by step from one flue to another, and the direction in which the carriage is
moved is determined by the position of the pawls d'. When the weighted
lever is at the right of the carriage, pawl d' will be in position to be taken by
the notches, and hence the carriage will be moved to the right a step each time the

page_text: rack is reciprocated. When the weighted lever d' is shifted to the left side of
the carriage, the other pawl d' will be brought in position to be taken by the
.notches of the rack when reciprocated, and thus the carriage will be moved to
the left.
As illustrated in Fig. 1, the carriage is in position to direct the scraper through
the tenth flue of the second row; that is, the carriage may be considered as having
started at the flue 1 of the upper row to travel across the upper row and back to
the left so as to be in the position shown to clean flue 10, counting from the right
of the 2nd row of flues.
The rotatable bar e is provided with pins e¹ e2 at one end, and at the other end
said bar is provided with a sleeve having pins e e e. A star wheel e' is pro-
vided upon one end of this bar e, and so arranged with relation to notches ein
the vertical bare that, as the vertically movable frame is raised and lowered, the
wheel will take the appropriate notches so as to turn the bar e to bring the
appropriate pins e e e e e into the path of the pivoted weighted lever to
shift the same so as to reverse the direction of the movement of the carriage as the
carriage passes from one row to another. The sleeve e is splined to the bar e at
the right end or portion thereof, as shown in Figs. 1 and 5. This sleeve is pro-
vided with a bearing el, as shown in Figs. 4 and 5, to which arm e, connected
with the rack bar do, is fitted so that as the rack 10 is reciprocated, said arm e",
which is fitted to said bearing e, may slide back and forth upon said bearing e
between the shoulders e, e¹³ thereof. The shoulders of this sleeve or bearing e
are a less distance apart than is the length of the stroke of the rack bar, and so
the sleeve e³ will be moved the amount of the difference between the length of said
stroke and the distance the collars are from one another each time the rack is
reciprocated. By means of the reciprocating sleeve e, the pin upon said sleeve
which is to do the shifting is kept out of the way of the weighted arm d' during
the forward stroke of the rack, but on the return the pin will be carried against
the said weighted lever to shift the same. This shifting taking place after the
notch, which will on the next reciprocation carry the carriage to the left, has
gone entirely past the pawl do, and thus the carriage is allowed to remain at its
extreme position to the right until the rack is again reciprocated, whereupon the
said notch of the rack engages with said pawl d³, which is now in position, and the
carriage is carried a step to the left on the return stroke of the rack.
We will now describe the manner in which power is transmitted from the shaft a
to the rack do to reciprocate the same immediately after the scraper has been
withdrawn from the fluc.
As shown in Figs. 1, 4, 6 and 15, a clutch f, is provided upon shaft a. This
clutch is held out of engagement by a latch f', which is normally in the path of
the spring catch until at the proper time the said latch f is pushed aside by the
rod or bar connected at f³, which is brought into position to be thrust longitudinally,
as will be explained more in detail later, at the time the scraper is withdrawn from
the flue. The spring catch fis thus left free to move outwardly, so that the
pin provided thereon will engage with the pin provided upon the collar f
as shown in Fig. 16, which collar is secured rigidly to the shaft a so as to move
therewith. The cam roller f7 mounted upon the clutch, when the clutch is thus
brought into engagement with the collar and shaft a, will be carried in the
direction indicated by the arrow in Fig. 15 about the cam roller guide provided
in the swinging segment gear f®, and thus the said segment gear will be swung
upon its pivot 10. The segment gear f' is in engagement with the pinion fi
provided upon the upright shaft f¹²¸°
Thus it will be seen that whenever the latch f¹ is thrown out of the path of the
spring catch, the pivoted. segment gear will be reciprocated, and thus the
shaft will be turned back and forth. It is by means of this reciprocal
movement of the shaft that the reciprocating motion required is imparted to
the rack do. Any suitable mechanical connection may be made between the
shaft, and the rack d¹0.

page_text: The connecting mechanism we preferably employ consists of the chains geach
fastened respectively on different sides of the wheel g² carried upon said shaft 1.
The chain is connected with the rack 10 by means of a link g. The other
chain is connected by the link g with the chain, which after passing over the
loose sleeve g is attached to the rack 10. When the shaft f12 is reciprocated the
chains or cords g g will be wound upon and unwound from their grooves respectively
upon the wheel; that is, during the first movement of the segment gear, the
chain g will be wound upon its groove, thus drawing the link to the left, and
hence through the medium of the chain g and sleeve g the rack do will be moved
a stroke to the right. When the segment gear returns, the shaft will be
moved in a direction to wind up the chain g, and thus through the link connected
directly with the rack 10, the rack will be moved to the left. The rack
reciprocated engages with the pawls of, the carriage, as before described, to move
the carriage a step in one direction or the other. It is the releasing of the spring
latch by moving the latch f which determines the time of the movement of the
carriage, and as before stated this movement must take place immediately after the
scraper is withdrawn from the flue.
I will now describe the lowering and hoisting mechanism, whereby the vertically
movable frame upon which the carriage is mounted is lowered and raised by power
communicated from the shaft a. The clutch h upon the shaft a, by means of
which the lowering and hoisting movements are transmitted from the shaft is,
generally speaking, similar in construction to the clutch previously described. In
fact, the fixed collar may be the precise counterpart of the collar of said
clutch. The clutch is best illustrated in Figs. 1, 6 and 17. When the spring
catch is in engagement with the latch the shaft does not move the clutch, and
the clutch remains in the position shown in Fig. 1. The cam carried on the
sleeve on the loose portion of the clutch, acts upon the cam roller, which is
mounted upon the lever 1, when the said lever is locked by the latch or
detent, as shown in Fig. 17. It is only at one time during the operation of the
machine we have illustrated, that the lever is thus locked, and that is when the
flue 2 of row 7th having been cleaned, it is necessary to raise the carriage to pass
around the handle 8 of the man hole. The mechanism connected with the ratchet
disk for causing the latch or detent to lock the lever to cause the same to act
as a bell crank to lift the rack h, meshing with the pinion 410 of the windlass 4",
will be explained after we have described the releasing or lowering mechanism
connected with said clutch h.
The chain or cord 12 passes over the sleeves 13 and down to the bar c, or
rather to studs projecting from said bar c. The weight of the frame acts upon the
chain or cord, but the chain is kept from unwinding by the escapement which
consists of the detent and the pins 16. When the lever of the detent is
moved out of engagement with the one of the pins with which it happens to be
in engagement, the frame will be lowered by gravity, the windlass simply turning
to permit the chain to unwind. In my machine, as illustrated, the windlass will
turn half way around each time the escapement lever is operated.
The escapement lever is operated in the following manner. When the latch ³,
as shown in Figs. 6 and 17, is moved out of engagement with the spring catch /²
the pin carried upon the spring catch 2 comes in contact with the pin upon the
clutch collar ', thus causing the disk to revolve with the shaft a. A. pin ",
carried upon the disk, comes in contact with the guide 20 provided upon the
detent arm, causing the said detent arm to move to the left, thus causing the
detent lever is to move to the right out of the path of the pin 10 with which it
was engaged and into the path of the next pin, thus permitting the windlass to
turn one-fourth way around. Then the windlass is brought to rest for an instant
by the engagement of the detent lever 15 with the next pin 10 upon the periphery
of the drum. As the disk continues to revolve the pin slides from the
guide, and the detent arm falls to the right and is held to the right by the
disk upon the lug 48 provided upon the detent
sliding of the periphery of the

page_text: arm A portion of the disk 1 is cut away so that it will not slide upon lug 18
while the pin is in contact with the guide . This movement of the detent
arm to the right causes the detent lever 15 to move to the left again, into its
former position, thus disengaging the pin with which it was for the instant in
contact and permitting the windlass to make another quarter revolution, when it is
again arrested by the detent lever coming in contact with the pin diametrically
opposite the pin which was in engagement with the detent lever, before the clutch /
caused the disk to revolve. Thus the windlass is permitted to turn half way
around at each engagement of the clutch h, but this semi-revolution is made up of
two quarter revolutions caused by the detent lever moving into the path of the
second pin for an instant.
The weighted bell crank lever i is connected by means of link with the hook ;
this hook is connected with the rack bar which meshes with the pinion 10 of
. the windlass. When this weighted bell crank lever is lifted the link will be
thrust in a direction to cause the catch to go over the lever to engage
therewith. The ratchet wheel, which will be presently explained in detail, is
combined in such manner with this bell crank lever i as to cause the hook or
latch to engage with the lever just before the latch is disengaged from the
catch. The clutch is thus brought into engagement with the shaft a and the
cam carried by the clutch, is forced against the cam roller carried upon
lever, and thus the lever is raised, drawing up with it at the same time the
hook and the rack A, which meshing with the pinion of the windlass, turns
the windlass to wind up the chain connected with the vertically movable frame,
and thus the frame and the carriage mounted thereon, are raised. As before
stated, it is only necessary to raise the carriage once during the operation of
cleaning the flues of the boiler like that illustrated, this being when the carriage is
to pass from flue 2 of the 7th or last row, to flue 7 of the 6th row to pass around
the cover of the man hole. If the arrangement of the flues in any case should be
such that it would be necessary to hoist the carriage more than once during one
operation of cleaning, it would only be necessary to arrange for lifting the weighted
lever i as many times and at the moments required.
The driving shaft a may be driven by any suitable power and the clutch a'
remains in engagement with the driving wheel until the work is completed, where-
upon the clutch a' is automatically moved slightly upon the shaft a², away from the
hub of the driving wheel. The clutch is moved longitudinally upon the shaft a²
by means of the rod, which is provided with the yoke, which yoke rests in the
groove provided in said clutch a'. Upon the rod k is the collar k rigid therewith. To
this collar is pivoted the link k³, provided with a handle. This link &³ is attached
to the bell crank lever k³.
When the machine is started, the handle is thrown to the position shown in
Fig. 1. The movement of the clutch a' away from the hub of the wheel a is caused
by vibrating the bell crank lever on its pivot &, after the last flue is cleaned, a
pusher being thrust against said bell crank lever as will be explained more in
detail in connection with the ratchet wheel.
I have thus described the actions of the various mechanisms by which the scraper
is thrust in and withdrawn from a flue, and carried along step by step from one
flue to another and lowered and raised as required by the position of the flues. I
have also described how the machine is thrown out of employment automatically
after all the flues have been cleaned. I have, however, only briefly referred to
the means whereby these various movements are brought into operation and in
proper sequence, and controlled as to time and action with respect to one another.
The ratchet wheel shown in Figs. 1, 2, 3, 7, 9, and 10 should be provided with
as many teeth in its periphery as there are flues to be cleaned; that is, the
mechanism between the ratchet wheel and the carriage is so arranged that when
the ratchet wheel is rotated one notch, the carriage will be moved one step, that is
to the next flue.
There being seventy-two flues, and four, that is 7, 6, 5, and 4 of the 6th row,

page_text: being cleaned twice each time, the ratchet wheel is proved with seventy-x
teeth. The lever m is provided with prongs which ride back and forth in the
thread or spiral groove of the worm clutch between the limiting stops m' m² therein.
This lever m is pivoted at m³ to a stud carried on the shifting lever m. This
shifting lever m is provided with a yoke or stirrup, as shown in Figs. 3 and 11,
which is adapted to embrace the worm clutch, and when shifted acts to change the
engagement thereof between the different pinions. The weighted lever m³ tends
to hold the shifting lever m* forward or to the right so that the lock mo may be pressed
against the pin m², either on one side or the other of the tongue m. The lever m
is provided with springs m and m on opposite sides thereof, which springs are
compressed against stops mm respectively as the lever mis carried back and
forth by the worm. The shifting lever m is provided with a slot m³ at the stud m",
which permits the lever m³ to move longitudinally so that the tongue m* may pass
over the pin when the lever is moved longitudinally.
As shown in Fig. 2 the pin upon pinion 6 is just impinging with the pin upon
the lower end of the worm 3 and the worm is just beginning to rotate to carry the
pin m² to the right. As the worm rotates the end of the lever m fitting in the
grooves of the worm will be carried downward. As the lever m moves downward
the spring will press against stop m¹ and as the lever m continues its downward
motion the tension of the spring m acting against said motion will increase. When
the forked end of the lever m following the groove of the worm has descended far
enough, the pin m' will impinge against the member of the forked end of lever m
that is on the back side of the worm as seen in Fig. 2, and will impart to it a
motion to the left. This will cause the pinion m³ carried upon lever m³ to move to
the left, moving m to the left and the weight m will be raised. When the lever m
has moved to the left by such a distance that the tongue m no longer presses
against the pin m', the spring m10 reacting upon stop m2 will throw the end of
lever n upward and the weight m³ descending will thrust lever m to the right
thus bringing tongue m above pin m and locking said lever m. But the throwing
of the end of lever m' upward carries the worm 3 upward so that the pin carried
thereon will engage with the pin upon pinion and the said pinion will now rotate
in an opposite direction to carry the end of lever m upward until the upper
member of the fork upon the end thereof impinges with pin m² when lever m
will be thrust to the left to cause the worm 3 to engage with pinion b¹.
The worm clutch in Fig. 2 is shown just engaging with the pinion ', and the
stop m² in the thread on the worin just starting to turn or move away from the
prong of lever m. The bifurcated end of lever m will then be carried down until
the stop comes against the under or back prong of lever m. While the lever m
is being carried down from the position shown in Fig. 2 until its downward motion
is arrested by the stop m', the pawl m will be carried up to slowly rotate the
ratchet wheel. It will be observed that the pawl m is normally held by the
weight m towards the ratchet wheel 7. Motion of the lever m is imparted to
the pawl m through the link m, the lever being pivoted at m¹. Any other suitable
lever mechanism might be used with the lever m.
The ratchet wheel when advanced by the pawl m is kept back by the click m¹;
thus each time the lever m makes a complete excursion from stop m² down to
stop m' and back again, the ratchet wheel 7 is rotated a single notch. When the
lever m is forced longitudinally by the stop m², the pushing rod is in position to
be forced longitudinally by the plate n' carried on said lever m, and thus force the
latch out of engagement with the spring catch f of the clutch so that the
clutch is brought into action and reciprocates the bar and thus moves
the carriage, as before described. The rod n is thus pushed each time the ratchet
wheel moves a notch, except when one of the pins n² coming under the guide n³
raises said guide n³ and hence the rod n, so that the plate n passes under said
rod 1, in which case the clutch is not operated. As shown in the drawing
Fig. 1, there are five times when the machine is. performing an operation when
the carriage must not be moved longitudinally, but simply directly down, and

page_text: the pins n², 3, etc., are placed in position accordingly upon the ratchet wheel 7.
That is the carriage is not moved longitudinally in passing from the first row
to the second, from the second to the third, from the third to the fourth, and
from the fifth to the sixth; thus there are four times when the plate a' must pass
the rod n, and hence four pins n² are provided.
The pushing rod o is connected with the latch of the spring catch 2 of
latch. The under or inner edge of plate n¹ is cut away, as shown in Fig. 11, so
that the plate n' does not come against the rod o to push the same longitudinally,
except when the rod o is slightly raised. The vertically movable frame on which
the carriage is mounted must be lowered seven times and raised once during the
process of cleaning a set of flues arranged as shown therefore eight pins o¹ 02 03 04
05 06 07 08 are provided upon the rear side of the ratchet wheel, as shown in Fig. 10,
and so arranged as to come against the guide 02, thus slightly raising the rod o³,
and hence the rod o whenever the said frame is to be lowered or raised by the
windlass. Thus pin o¹ raises guide o at the end of the first row, and the clutch h
is brought into action to operate the escapement.
The pins oooof and are brought into action to lower the carriage at the
ends of the second, third, fourth, fifth, and sixth. rows. The pin of is brought
against the guide o to raise the rod o and bring the latch into action when the
carriage is to pass from flue 2 of the seventh row to flue 7 of the sixth row, and
the pin o8 is brought into action to lower the frame when the carriage is to pass
from flue 4 of the sixth row to flue 7 of the seventh row. The pin pupon the
face of the ratchet wheel acts in connection with the weighted bell crank lever i
to bring the catch into engagement with the lever 1, as before described while
at the same time, the pin of acts to raise the rod o to bring the clutch into action.
Thus the frame and with it the carriage is raised at the right moment.
When the last flue, that is flue 8 of row seventh, is cleaned, the cluich a¹ is
thrown out of engagement with the driving wheel o automatically by means of the
pin upon the disk which is brought up under the guide, thereby changing the
position of the push lever ², so as to be in the path of the plate of lever m.
The push lever is thus forced longitudinally against the bell crank, and this
longitudinal movement is imparted to the rod k to move said rod, and hence the
clutch a' away from the sprocket wheel a. I preferably place the pin q upon the
disk in such position that the machine will not be thrown out of gear until
the carriage has been moved the distance of one step to the right of the last flue of
the series.
As shown most clearly in Figs. 3, 7 and 12, a graduated disk is provided in
connection with the ratchet wheel 1, the spaces on the indicator corresponding
to the notches in the periphery of the ratchet wheel. As the ratchet wheel is turned
the indicating disk turns with it, and the pointer remaining at rest will indicate
the position of the ratchet wheel and consequently that of the carriage in its course
over the flues, the division on the dial or indicator when opposite the pointer
indicates that the carriage is in its highest position at the left, ready to begin
cleaning flue 1 of the first row. The pointer, as illustrated, being at the
10th division of space 2nd of the dial indicates that the carriage is in the position
shown in Fig. 1, that is opposite flue 10 of the 2nd row of flues.
It will be seen that I have practically dispensed with springs for retaining the
various levers, pawls and rods in their normal position, weights being used in place
of springs. I prefer the weights, yet it is evident that springs might be used to
perform the functions of the weights. It is obvious that the mechanical details of
my machine might be varied indefinitely by those skilled in the art, without
departing from my invention.
Having now particularly described and ascertained the nature of my invention,
and in what manner the same is to be performed, I declare that what I claim is :
1. In a flue scraper, the employment of a scraper adapted to be positively forced
into and positively withdrawn from the flues in successive order.

page_text: 2. The combination with the shells forming the chain, of the flue scraper carried
thereby, with a guide for said chain and means for causing the guide to travel step
by step from one flue to another.
3. The combination, with the pinions driven in opposite directions, of a worm
clutch, means for changing the engagement of the worm clutch from one pinion to
the other, and the chain of a flue scraper with linkage between the shaft of the
worm clutch and said chain, whereby the movement of the chain is reversed in
direction when the engagement of the worm is shifted from one pinion to the
other.
4. The carriage provided with the guide for the chain, and the clutch / connected
with the driven shaft and adapted to be brought into action by the worm clutch to
move the carriage step by step as required.
5. The clutch / mounted on a driven shaft with mechanism controlled by the
power which reciprocates the chain carrying the scraper, whereby the frame on
which the carriage is mounted is lowered.
6. The combination, with the clutch of the latch and the lever with
the rack and the windlass, whereby the windlass is turned to raise the carriage.
7. The shifting lever m* in combination with the bifurcated lever
provided
with the plate and the worm clutch, whereby the worm clutch is shifted longi-
tudinally upon its shaft to change the engagement thereof between oppositely
driven pinions.
8. The carriage provided with pawls in combination with the rotatable bar e
provided with pins, and with a reciprocating sleeve e for shifting the position of
the pawls to change the direction of the movement of the carriage.
9. The rack bar d combined with means for reciprocating the same, and the
carriage provided with pawls linked together, and the shifting device d' for
changing the position of the pawls.
10. A ratchet wheel provided with notches and pins in combination with rods or
levers and a pawl n' adapted to be moved against said rods or to pass by the same,
according to the position of the ratchet wheel.
Dated this Twenty-seventh June 1892.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.