IMPROVEMENTS IN RAG ENGINES
Year: 1867

page_text: LETTERS PATENT to James Roger Crompton, of Elton Paper Mills, Bury,
in the County of Lancaster, for the Invention of "IMPROVEMENTS IN RAG
ENGINES."
Sealed the 13th August 1867, and dated the 22nd February 1867.
PROVISIONAL SPECIFICATION left by the said James Roger Crompton
at the Office of the Commissioners of Patents, with his Petition, on the
22nd February 1867.
I, JAMES ROGER CROMPTON, of Elton Paper Mills, Bury, in the County of
Lancaster, do hereby declare the nature of the said Invention for "IMPROVE-
KENTS IN RAG ENGINES," to be as follows:-
This Invention relates to improvements in the roll and bottom plate of
rag engines employed in reducing fibrous material to pulp, whereby the
necessity for grinding or renewing the edges of the bars and plates is obviated,
and consists in the employment of a series of adjustable bars or strips of steel
which are of the same or nearly the same thickness throughout, so that the
actual cutting edge will remain uniform or nearly uniform as the bars wear
away. These adjustable steel bars are supported by fixed iron or other metal
bars in the circumference of the roll, and their, adjustment for wear is effected
by having a projection made on the inner edge of each steel bar, which fits
with one or other of a series of grooves or notches made to receive it on the
faces of the fixed supporting bars. Wooden slips or wedges are inserted in
the space between one face of the steel bar and the face of the next or

page_text: succeeding supporting bar so as to assist in holding the several steel bars in
their places. These wooden slips are secured by a hoop or ring of brass or
other metal taking into an annular groove at each end of the roll, such hoops
or rings being by preference made in segments for convenience of adjustment,
and being held in their places by screws, bolts, or otherwise. The hoops or
rings may be either bevelled on the outer periphery and on their inner face
so as to act as a dovetail in holding the slips or steel bars in their places,
and in lieu of bevelling such rings they may be provided or formed with teeth
or projections on their inner faces taking into corresponding notches in the
ends of the slips and iron supporting bars. The bottom plate of the engine is
composed of a series of steel blades similar to those employed in the roll
bolted together and capable of adjustment vertically between and in the
dividing bars by the aid of notches and projections, as described in reference to
the roll.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Roger Crompton in the Great Seal Patent Office
on the 21st August 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
ROGER CROMPTON, of Elton Paper Mills, Bury, in the County of Lancaster,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of February, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the.
said James Roger Crompton, Her special license that I, the said James
Roger Crompton, my executors, administrators, and assigns, or such others
as I, the said James Roger Crompton, my executors, administrators, or
assigns, should at any time agree with, and no others, from time to time and
at all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN RAG ENGINES," upon the condition (amongst others) that I,
the said James Roger Crompton, my executors or administrators, by an instru-
iment in writing under my hand and seal, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal Patent

page_text: Office within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said James Roger Crompton, do hereby
declare the nature of my said Invention, and in what manner the same is to be.
performed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say:-
:
My said Invention relates to improvements in the roll and bottom plate of
rag engines employed in cleansing and reducing fibrous material to pulp,
whereby the necessity for grinding or renewing the edges of the grinders or
bars and plates is obviated, and consists in the employment of a series of
adjustable bars or strips of steel as grinders which are of the same or nearly
the same thickness throughout, so that the actual cutting edge will remain
uniform or nearly uniform as the grinders wear away. These adjustable steel
bars or grinders are supported by fixed iron or other metal backing bars in
the circumference of the roll, and their adjustment for wear is effected by
having a projection made on the inner edge of each grinder which fits into one
or other of a series of grooves or notches made to receive it on the faces of the
fixed backing or supporting bars. Wooden slips or wedges are inserted in the
space between one face of the steel grinder and the face of the next or.
succeeding backing bar so as to assist in holding the several steel bars or
grinders in their places; these wooden slips are secured by a hoop or ring.
of brass or other metal taking into an annular groove at each end of the roll,
such hoops or rings being by preference made in segments for convenience
of adjustment and being held in their places by screws, bolts, or otherwise.
The hoops or rings may be either bevelled on the outer periphery and on
their inner face so as to act as a dovetail in holding the slips and steel grinders
in their places, or in lieu of bevelling such rings they may be provided or
formed with teeth or projections on their inner faces taking into corresponding
notches in the ends of the slips and. iron supporting or backing bars. The
bottom plate of the engine is composed of a series of steel blades similar to
those employed in the roll, bolted together and capable of adjustment vertically
so as to compensate for wear between and in the dividing bars by the aid of
notches and projections, as described in reference to the roll, or by other suitable
or equivalent contrivances.
And in order, that my said Invention may be fully understood I shall.
now proceed more particularly to describe the same, and for that purpose
shall refer to the several Figures on the annexed Sheet of Drawings, the
same letters of reference indicating corresponding parts in all the Figures.

page_text: Figure 1 of the Drawings represents a partial end elevation and transverse
section of a rag engine roll constructed according to my said Invention; Figure 2
is a corresponding side elevation and partial vertical longitudinal section of the
same; and Figure 3 is a full sized detail of a grinder and its backing bar
detached.
A is the body of the roll keyed on to a shaft a, and on the periphery of
this roll are number of projections B, B, running the whole length of it.
In the spaces thus formed between these projections I place any convenient
number of grinders or blades of steel F, F, and a like number of stronger
blades or backing bars G which may be made of steel, iron, or brass; these
latter are intended as a support to the blades of steel which constitute the
grinders; the grinders with their supporting bars G at the back of them are
kept at suitable distances from one another by wedges or dividers of wood H, H.
Between each space formed by the projections on the periphery of the roll I
place an iron wedge C; this wedge and the wood dividers, steel grinding
blades, and backing bars are all made to fill up the space between each
projection; at each end of the roll a groove is formed for the reception of a
hoop D, and a corresponding groove is also formed in the ends of the iron
wedges C for these hoops to fit in; the hoops are fitted with screwed bolts E
at each point where they intersect the wedges C, and the object of these bolts
is to draw down the wedges towards the centre of the roll; by this action of
the wedges C the whole series of grinders, backing bars, and dividers are
made to fit tight and securely in the spaces allotted to them between the fixed
projections B on the periphery of the roll. To prevent the pulp or material
to be operated upon from getting into the grooves and recesses necessarily
formed in the end of the roll for the reception of the hoops and bolts I cover
up the whole with segments of brass plates I made secure with screws into
the sold ends of the roll. These plates are also made to serve as a further
security in checking the tendency which the grinders and other parts have to
fly out by the action of centrifugal force. For this purpose the plates have a
flange or projection on their inner face which is made to fit into a groove
turned into the ends of the grinders, backing bars, and dividers. The
Drawing shows the grinders projecting about a quarter of an inch above
the backing bars, and when the grinders are worn down to the edges of
the backing bars the roll is constructed so as to afford an easy means of
raising them up at intervals as required to compensate for wear and tear.
For this purpose there is a series of grooves formed in the front face of the
backing bars, as shown clearly in the detail Figure 3. The steel grinding
blades have a flange or foot at their lower edge running the whole length of

page_text: the blades, and this fits in the first instance into the bottom grove of the
backing bars and is consecutively raised into the others as the grinders wear
away, thus allowing the edges of the grinders constantly to project above the
edges of the backing bars.
:
:
The operation of raising the grinding blades is accomplished in the
following manner: The brass end plates I are first removed by taking
out the screws that hold them to the body of the roll; this gives admission
to the bolts E which hold down the iron wedges C, and by slackening these
bolts the wedges are raised, thus liberating the grinders, backing bars, and
dividers. The grinders are now raised into the next groove of the backing bar;
and the whole are again made secure by tightening down the wedges and
replacing the end plates when the roll is again ready for work. This
process is repeated each time the grinders become worn down to the edges of
the backing bars.
The grinding blades according to my Invention not being tapered or
bevelled maintain one uniform grinding edge, and this edge may be adapted
by the thickness of the steel blades to that most suitable for the nature of the
material to be operated upon. The facility with which the grinders can be
taken out of the roll is a great improvement on the old plan of constructing a
roll. As the grinders only wear down about a quarter of an inch before they
are again raised the roll never varies more than about half an inch in diameter
and the spaces between the grinders requisite for the purpose of drawing in
the material and keeping up the circulation of the same is maintained nearly
uniform. I also obtain considerable economy both in time, steel, and motive
power over the method of construction hitherto adopted, wherein it has been
usual to permanently fix on the periphery of an iron or wood roll a series
of steel blades bevelled or tapered to a requisite cutting edge. Now as this
edge in the ordinary wear and tear of grinding against the bottom plates became
too dull it was customary either to chip on a fresh bevel or to take the roll
apart and replace with new grinders or forge out the old ones to a new
bevel.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original
and therefore claim as the Invention secured to me by the herein-before in part
recited Letters Patent is,-
First, the general construction and arrangement of rag engine rolls and
bottom plates, as herein-before described.
Second, the application and use to and in rag engine rolls of thin steel blades

page_text: of uniform or nearly uniform thickness throughout and supporting such blades
by bars at the back, substantially as herein-before described.
Third, the system or mode of rendering the grinding blades of rag engine
rolls and bottom plates adjustable so as to compensate for wear and tear.
In witness whereof, I, the said James Roger Crompton, have to this my
Specification set my hand and seal, the
day of August,
One thousand eight hundred and sixty-seven.
JAMES ROGER CROMPTON. (L.S.)