IMPROVEMENTS IN AND CONNECTED WITH CALENDERING APPARATUS EMPLOYED IN FINISHING PAPER
Year: 1885

page_text: Employed in Finishing Paper.
I, RICHARD SMITH of Sherbrooke, in the County of Sherbrooke, Province of
Quebec, Dominion of Canada, Machinist, do hereby. declare the nature of my
invention for "IMPROVEMENTS IN AND CONNECTED WITH CALENDERING APPARATUS
EMPLOYED IN FINISHING PAPER," and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :-
This invention relates to means whereby a continuous rapidly travelling paper
web may be automatically forced to pass between and around "Calender-Rolls," so
called, and thus in its passage to receive a smooth and finished surface, thereby it
is adapted for general commercial purposes.
Hitherto in the process of calendering the paper-web as it passes continuously
from the driers of the machine has been conducted and guided through the stack
of Calender-Rolls by the fingers of the machine-tender and serious accidents are
continually occuring in which the fingers of the operator get jammed and terribly
bruised, and the danger is multiplied, since the. paper-web has to be restored every
time its continuity is interrupted for any cause whatever; moreover in the process
of "mending-up" a large amount of "broken" is produced, because the draught
and tension across the paper-web is not uniform and folds or wrinkles are caused
which at once make a crack or break in the paper and these continue until said
tension is properly restored; the paper during this interval being rendered useless
for commercial purposes.
To overcome these objections and to render the waste of paper less and make the
operation of "mending up," less laborious to the operative and to reduce the danger
to a minimum, I have designed the following improvements consisting Firstly, in
the employment in combination with a series of wind-cases or shields alternately
arranged and disposed over one half of the periphery of each roll, of a current of
air, steam or gas, to guide the paper-web through the stack: secondly in the use of
'doctors," so called, to prevent the web from winding up around a roll, în lieu
of advancing down over the surface of the next adjacent lower roll; and thirdly in
the employment of a pair of swift running draught rolls disposed upon the free end
of a swinging table or carriage, whereby the slack is taken up and proper tension
produced upon the paper-web prior to its introduction around and through the
"

page_text: rolls forming the calender stack, all of which arrangements and construction of
parts I will now proceed to fully and completely describe.
In the drawings accompanying this specification I have shown in Fig. 1 a side
elevation of my apparatus arranged as a whole and fitted upon the calender-roll
stack and drier-frame; the two upper rolls being in section. Figs. 2 and 3
represent a plan of the apparatus and Fig. 4 a longitudinal and Fig. 5 a transverse
section, both enlarged, of one of the "doctors," so called.
In these drawings I have shown a portion of the drier-frame of a paper machine
at A with one of the driers at A¹ and with the paper rolls at a a mounted thereon.
Suitably disposed in the standards B B, bolted to the sides of the drier-frames is
the swinging table C, the pivot of which is the shaft D extending across the
machine, while a corresponding shaft D¹ is similarly disposed upon the free or
swinging end of said table in proper bearings. This latter shaft supports and
carries a draught roller E, which cooperates with a like roll E', spring actuated, in
order to produce friction between the two rolls and consequent requisite tension
upon the paper-web.
The top surface of this table is of wood properly smoothed and bolted to the
side frames to stiffen the table and at the same time give it the requisite lightness.
In order to actuate the draught rolls E E¹, I have attached to the ends of the
shafts D D driving pulleys F F, suitably bolted, of which the latter F¹ is the
driver while motive power is furnished by a second belt and pulley F's connected
thereto.
Between the calender stack and the end of the drier frame, I have mounted two
curved arms or housings G G which support parallel shafts c c¹, carrying a series
of rolls d d d d' respectively; while running over these latter is a series of endless
belts or tapes d' d², similar to those used in printing presses, which extend around
a second series of rolls e e¹, of the same diameter as d d. The rolls e e¹ being
mounted upon their shafts ff' and driven by the driving pulley G³ and at the
same speed as the first series.
When the swinging table C is moved upward, it is evident that some quick and
ready means must be adopted by which to sever the continuously travelling paper-
web just prior to its alignment with the adjacent faces of the endless belts d³ d³
before entering between them, to accomplish this object I have secured a saw-
toothed plate or cutter g upon the extreme outer or swinging end of the table C
and a fixed or immovable corresponding one at g¹, between the housings G G¹; the
teeth of these plates interlock and at the instant the plate g has passed by the
fixed cutter g¹ the paper is severed without being stopped and is free to continue
its rapid passage supported between the endless belts dd, which carry it to the
stack of calender rolls.
When the paper-web is travelling continuously and without interruption the
table remains in its normal or raised position, as shown by the dotted lines in Fig. 1
and is locked to the standards G G¹ by any well known mechanical device, as a
spring catch or bolt, while the tension or pull of the rolls E E¹ may be removed
entirely by means of a lever or other equivalent, which will nullify the tension of
the springs upon the rolls E E', which tension is required, when the web is broken,
but after being mended up must cease as soon as the slack caused by a break has
been removed and the table raised.
The side standards or housings supporting the calendar rolls are shown at H H²,
while the rolls are represented at h h h h h suitably mounted and journaled in
the usual adjustable boxes. Since I propose to use a blast of air or its equivalent,
either suction or pressure, in order to guide the paper-web automatically through
and around the rolls, it becomes necessary to partially cover and protect a portion
of the surface of the calendering rolls in order to produce the desired effect by
confining the current of air and thus oblige it to assume a certain direction
and carry with it the advance end of the paper-web to be led between the rolls;
I have therefore shown as partially closing the exterior peripheries of said rolls,
a series of alternately oppositely disposed wind-cases III etc, which are plates

page_text: bent preferably concentric with the curvature of the rolls and extending their
entire length.
Furthermore I have rendered said cases adjustable with respect to the peripherie
of the rolls; that is they are made to advance towards or withdraw from said rolls,
according as a blast of air is required to conduct the paper-web, when mending up.
In order to accomplish this readily and operate the entire series at one moment,
I bave pivoted at the base of the front standard H a hand lever H' to which are
attached two parallel upright connecting rods i i, which operate similar oppositely
disposed bell crank levers J J¹ J' etc. pivoted upon supporting rods
etc.
while short arms or links k k¹ k* are fastened to the wind-cases, the ends of which
are secured to and move within suitable guides K K' attached to the standard H;
parts similar to all these are duplicated upon the rear standard H¹ in order to
move both ends of said cases the same amount and at the same instant and thus
maintain them equally distant at all times from the surface of the rolls.
In revolving bodies centripetal force always exerts a somewhat important func-
tion upon an object located upon its surface, hence and more especially in paper
making machines the paper web has a great tendency to adhere to the surface of
the calender rolls and pass continuously around one roll, in lieu of advancing on
and around the next adjacent roll. This fact is especially noticeable in the manu-
facture of light weight paper and I have found it necessary to employ in connection
with the wind-cases, above alluded to, a device called a "doctor."
In this especial instance I have terminated the upper extremity of the wind-cases,
which enter between two rolls, in the shape of a straight steel bar or doctor M,
which is bevelled to coincide or approximately so with the line of a tangent to the
roll, at the point where said doctor touches said roll, and I find that the most
effective position is a point a short distance to one side of the place of contact
between the two rolls, where the exterior surface of the top roll first begin to
assume an upward path of movement in its rotation.
Hence when the paper after a break is to be mended up the operator raises the
lever and advances the wind-cases towards the rolls and in close proximity thereto,
while their respective doctors are brought in close contact with the upwardly
moving surface of each roll, and thus any tendency which the paper web may
have, as it emerges from one side between two rolls to the other to pass up and
wind around the top roll of the pair, is instantly checked by the doctor, which as
the curve of the latter coincides with the interior curve of the wind cases, guides
the paper along in its proper course down around the lower roll of said pair; the
same action ensues as the paper web emerges from beneath the next two rolls, and
meets the next doctor, and so on down beneath the rolls composing the stock.
Mounted upon the wind-cases with which they are suitably connected, I have
disposed a series of pipes etc. the latter communicate with a blower L,
either exhaust or pressure, and from which the air is obtained as a means for
guiding and passing the paper-web through the rolls. In the present instance
I assume a pressure current is applied and continuously passing in the direction of
the path of movement of the paper-web, and I bave consequently perforated the
pipes at any acute angle with the peripheries of the rolls, so as to more
readily pass along and maintain the air current in the same direction with the
rotation of the rolls.
The doctors M may be made simply as a prolongation of the wind-cases but
since they remain in contact with the rolls every time the paper-web is mended,
it necessarily follows that rapid wear will ensue and that the hand lever H' must
accordingly be further actuated to bring said doctors into proper position, this
however after much use would bring the wind-cases too closely to the rolls, hence
propose, as shown in Figs. 4 and 5, spring actuated doctors in which either a
series of steel fingers m m etc. may be attached to a plate M or a continuous
perforated steel bar or plate may be inserted within a recess formed in the wind-
cases aud actuated by springs n n etc. By this device I can easily maintain the
doctors in proper contact with the peripheries of the rolls to compensate for the

page_text: wear of the former and thus actuate the lever H' always a fixed amount, just
sufficient to bring the wind-cases in proper relation to the surface of the rolls.
Furthermore the interstices or spaces between the fingers on the perforation in the
bar or plate, when used permit the air to pass through without obstructing it
materially.
The operation of this apparatus embodying my invention is as follows, with
the various rolls and pulleys moving in the direction of the arrows as indicated.
The paper-web has been interrupted and broken for some cause and it must be
restored, hence the operator drops the table C into a horizontal position and lifts
the lever H* to bring the doctors to bear against the rolls h h¹ h³ etc. and the wind
cases III³ near to the surfaces of said rolls; the paper is then passed around the
rolls a a and drier A¹ thence over the table C between the quick running rolls E E¹
which exert sufficient tension upon the web commensurate with its strength, hence
adjustable, but not enough to break it. Immediately upon the proper restoration
of the tension and removal of the slack consequent upon the "mending-up," the
operator swings the table upward, the paper-web meantime continuously passing
along until the movable cutter g has engaged with and passed the fixed cutter g¹
upon the arms G G¹. The paper-web is then instantly severed and the draught
rolls carry and feed it directly to the tapes d' d' d, whence it is conveyed to the
entrance of the wind-case I in a line directly at right angles to the calendering
rolls, an important feature, since it obviates the loss of paper incidental to the
ordinary method, where the paper-web is introduced at an angle with the axis of
rotation of the rolls. Upon the arrival of the advance end of the paper-web in
front of the wind-cases the pressure from the air current through the pipe 7 forces
it quickly around the roll h while the interior surface of said case maintains and
guides it in a proper direction between the rolls h and h¹. Immediately said web
emerges from between the rolls, although in close contact and with a tendency to
pass up and wind around the upper one, it at once encounters the doctor, which
removes it therefrom and compels it to follow the curve of the wind case I', when
the pressure from the air current emerging from the pipe still further advances
it and so on through the rolls of the stack, when it may either be passed around
onward and led through in a similar manner by means of a second series of
tapes d² d² to a second stack or be led to the reels upon which it is temporarily
stored.
I find a great advantage accrues by the operation of conducting paper through
calender rolls in the manner before premised; that is the current of air in passing
over the surface of the paper exercises a very decided influence in cooling the
heated continuous paper web as it passes from the driers. Hitherto it has been
customary to grind and finish the calender rolls cold, hence after being mounted in
proper position and the heated web has passed through them for any length of
time the rolls become hot and expand and the result is that the faces of the rolls
do not coincide since they were ground to fit when in a cool condition.
And I further find that a special cold blast of air applied across the web prior to
its entrance between the rolls of the stack and independent of the current inducing
the progress of said web through the stack accomplishes the cooling of the paper
thoroughly and permits the individual rolls to remain cold; hence there is no
expansion and the surfaces coincide exactly with the greatest degree of efficiency.
In the present instance I have shown the wind-cases movable with the doctors,
but in some cases they may be stationary and only the doctors movable back and
forth with respect to the rolls of the stack.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1st A series of revolving rolls over and between which passes a continuously
travelling paper web, in combination with mechanism which applies a current of

page_text: air or its equivalent to said web in the direction of the path of travel of the latter,
substantially as set forth..
2nd In a paper machine the combination with the driers and calenders of a pair
of quick running draught rolls, so arranged that the normal tension shall be
restored to the continuous travelling paper-web prior to its introduction between
Baid calenders, substantially as and for purposes herein described.
3rd In a paper machine the combination with the quick running draught rolls
the swinging table and the cutter or knife attached thereto, of the fixed cutter,
whereby the continuously travelling paper-web may be severed without cessation
of its movement and thence conducted to the calendering rolls, substantially as
described.
4th The combination with the driers and the calender rolls, of the swinging
table, of the quick running draught rolls and the endless belts or tapes by means
of which the continuously travelling paper web is conducted to the calenders in
paths of movement at right angles to their axis of rotation, substantially for
purposes set forth.
5th The combination with a series of revolving rolls of a series of alternately
oppositely disposed curved plates partially enclosing the peripheries of said rolls,
all arranged and operating substantially as described.
6th The combination with a revolving roll of a shield or cover, bent concentric
therewith and partially enclosing and adjustable with respect to its periphery,
substantially as stated.
7th The combination with a pair of rolls provided with and partially enclosed
by bent shields, of a spring actuated bar resting upon and in contact with the
surface of the upper roll, substantially as and for purposes set forth.
8th The combination with a roll h and wind-shield I mounted in suitable guides,
of the levers H J and the connecting rod k by which adjustment of the shield is
effected with respect to the periphery of the roll, substantially as stated.
9th The combination with the revolving rolls h h¹ etc. wind-cases I I¹ etc. of a
guide or "doctor" M provided with the spring actuated teeth m m etc. sub-
stantially for the purposes set forth.
10th A series of revolving rolls between which passes a continuously travelling
paper-web in combination with mechanism which applies a current of air to such
web prior to its entrance within the rolls for the purpose of cooling it, substantially
as described.
T