Improvements in and connected with the Method of Grinding and Trueing Cylindrical Surfaces.
Year: 1890

page_text: ate of Application, 4th Nov., 1890-Accepted, 20th Dec., 1890
COMPLETE SPECLICAL.TUN.
Improvements in and connected with the Method of Grinding and
Trueing Cylindrical Surfaces.
We, PETER HOWIESON and SIDNEY SMITH WHITTELSEY both of Atlantic Buildings
928-930 Street, Washington, District of Columbia, United States of America,
Engineers, 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:
Our invention relates to the production of cylindrical surfaces, and it has reference
more particularly to the manufacture of rolls, for calendering paper, or other purposes.
In machines for calendering paper and fabrics for rolling metal, and the like
purposes, it is of the utmost importance that the rolls shall be perfectly straight, so
that as two of them revolve adjacent to each other, the space between them shall
always be of uniform thickness at all points, both in the length and in the circum-
ference of the rolls, otherwise the material which has been passed between them will
not be of uniform thickness or finish which is a serious fault. It has hitherto
generally been the custom to grind the surfaces of such rolls to bring them to a
true cylindrical shape, and several machines have been devised to accomplish this
result. So far as we are aware, they all depend upon the action of a revolving
grinding wheel, arranged to be traversed in a line parallel with the axis of the roll
upon which the grinding wheel operates, the roll being mounted in bearings so that
it can be turned to bring every part of its surface under the action of the grinding
wheel. These machines are frequently defective however, owing to the practical
difficulty of preserving an exact parallelism between the path of the grinding wheel
and the axis of the roll, the variation due to the wearing of the wheel, the presence
of hard or soft spots in the wheel and roll, and other causes.
Moreover, this mode of grinding requires a special and costly machine, in which
each roll is separately treated.
Our process dispenses with all grinding wheels, and other costly machinery. It
can be carried out in a variety of ways, and though in some cases a special machine
may be desirable for applying it, yet such machine may be simple and inexpensive.
The process is adapted to finishing new rolls, and also to trueing old rolls which have
become worn or bruised. It can be applied to a set of new or old rolls mounted
in the machine to which they belong; or to one or more rolls removed from the
machine.
So far as we are aware, the grinding of a curved surface has heretofore been
effected by causing it to move in contact with another curved surface in such a
manner that the two surfaces move in opposite directions, or at different speeds, so
as to produce a rubbing action between them. We are not aware that it has ever
been proposed to grind a curved surface by simply rolling it in contact with another
surface, so that the two surfaces move in the same direction and at the same speed.
The trueing operation is greatly facilitated by giving one or more of the rolls an
axial reciprocating motion at the same time that the rolling is taking place. When
two or more rolls are reciprocated, the notion should be alternated, so that any two
adjacent rolls will move in opposite directions. The combination of end wise and
rolling motions causes the surfaces to react upon each other, and the presence of the
abrasive or grinding substances between them speedily reduces all inequalities and
brings the roll or rolls to a true cylindrical surface.
The abrasive or grinding substance may be any of the known materials or com-
pounds used for that purpose. We prefer a mixture of emery powder and oil. It
can be applied to the rolls in any convenient manner, as for instance, by a swab or
brush in the hands of an attendant, or by a set of distributing rollers similar to the
inking rollers in a power printing press.

page_text: The distributing rollers may be given an axially reciprocating motion if desired,
and may be composed of a material adapted to, assist in the grinding action though
this is not necessary.
In the drawings appended hereto, and to which reference is hereinafter made,
Figure 1 is an elevation of a set of calender rolls.
Figure 2 is an elevation of a similar set of rolls, provided with devices for giving
an axial reciprocating movement to certain rolls.
Figure 3 is an end elevation partly in section, of a machine similar to that
shewn in Figure 2, and provided with distributing rollers.
Figure 4 is an elevation of a frame provided with a set of rollers, for distributing
a grinding mixture upon the surface of a set of rolls.
Figures 5 and 6 are details.
Figures 7 and 8 are diagrams shewing other applications of the invention.
In some rolling machines, such as calendering machines, the rolls normally rest
upon each other. Such a machine is shewn in Figure 1, in which the frame A
supports a set of rolls B, B1, B2, etc., suitably journaled in boxes C which are free
to slide vertically in the frame A. In such a machine as this, it is only necessary
to apply the abrasive substance to the rolls and start the machine, in order to cause
the rolls to true themselves. In some cases special temporary attachments may be
provided to cause the rolls to reciprocate axially at the same time that they are
rotating in their bearings in rolling contact with each other. An arrangement for
this purpose is shown in Figure 2 in which the journals of a stack of rolls are
extended beyond their bearings at each end. The necks of the rolls B', B³, B³, B',
are shorter than the necks of the other rolls, so that the rolls named can have an
axially reciprocating movement in their bearings, while the remaining rolls have no
such motion. In order to produce the axial reciprocation of the rolls B¹, B³, B³, B'
their journals are fitted at one end, with grooved wheels D set obliquely to the axis
of the rolls. On the extended journal of the roll B2, is fitted a wheel D₁, having a
projecting flange, which engages with the groove in the wheels D on the rolls B'
and B3. A similar wheel D on the journal of the roll B, engages with the wheels D,
on the rolls B and B7. The extended journals at the other ends of the rolls are all
provided with gear wheels E meshing with each other, so that all the rolls are
positively driven at the same rate of peripheral speed. The gear wheels have suffi-
ciently broad faces to ensure their always remaining in mesh, while the rolls are
reciprocated. When power is communicated to the stack, the rolls B1, B³, B³, B²
will be given an axial reciprocation, as well as a rotary motion, which tends to
spread the grinding mixture evenly on their surfaces. The abrasive substance may
be applied by hand, or by a special device. This latter may consist of a set of
distributing rollers F, mounted in bearings f, temporarily attached to the frame of the
machine, as shewn in Figure 3. Those rollers may simply rotate in contact with the
rolls, but they may if desired, be given an axial reciprocation by means of certain
devices, such for instance, as that shewn in Figure 6. The roller as here shewn is-
made shorter than the space between its bearings, and is mounted loosely on a
stationary shaft G. A stud projects inwardly and engages with a double screw
thread cut in the shaft G, so that as the roller rotates by contact with the roll,
it will also be carried back and forth continuously on its stationary shaft G. The
ends of the shaft are non-circular or flattened, as shewn in Figure 5, and are received
in inclined slots in the bearings f, so that the roller constantly gravitates against
the rolls. When the rolls have been ground true, the wheels D D' and the gear
wheels E are removed. The rolls B', B³, B, B', are placed with their ends in line
with the other rolls, and collars or washers are inserted, between their boxes and the
ends of their short necks, so as to prevent any endwise motion. The rolls are then
ready for use..
When it is not convenient to attach the special devices for reciprocating the rolls
and feeding the abrasive substance to the calendering or other rolling machine, a
special framework A' Figure 4, may be provided, adapted to receive the rolls, in the
same relative arrangement they occupy when at work, and furnished with appliances

page_text: for rotating and reciprocating the rolls and feeding them with the abrasive substance,
preferably by means of distributing rollers F as shown.
In other cases, it may be convenient to arrange the rolls around the circumference
of a drum, as indicated in Figure 7, by which they can all be rotated by rolling
contact, and properly supplied with an abrasive mixture. In this arrangement, some
or all or none of them may be in contact with each other.
The process can also be carried out by placing the rolls side by side in contact or
not, as desired, on a horizontal or inclined plane surface, as indicated in Figure S, and
then rolling them back and forth on the said surface. Axial reciprocation may be
given them, if desired, and the abrasive substance can be supplied to them in any
convenient manner.
We have mentioned several different modes of carrying out the invention to shew
that the process does not depend upon any particular machine or device, but is capable
of a great variety of development.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
1. The process of trueing the surface or surfaces of a cylindrical object or of
cylindrical objects, which consist in applying to it or them an abrasive substance and
rolling it or them in contact with another surface, or with each other, substantially as
hereinbefore described.
2. The process of trueing the surface or surfaces of a cylindrical object or of
cylindrical objects which consists in applying to it or to them an abrasive substance,
rolling it or them in contact with another surface or with each other and giving one
or more of them at the same time an axial reciprocation substantially as hereinbefore
described.
3. The process of trueing two or more cylindrical objects, which consists in
applying to their surfaces an abrasive substance, rolling them in contact with each
other and at the same time imparting to them axial reciprocations in opposite
directions, substantially as hereinbefore described.
4. The process of trueing a set of calendering rolls, which consists in mounting
them in bearings, applying to their surfaces an abrasive substance, and rotating them
in rolling contact, substantially as hereinbefore described.
5. The process of trueing a set of calender rolls which consists in mounting them
in bearings, applying to their surfaces an abrasive substance, rotating them in rolling
contact, and at the same time giving one or more of them an axial reciprocation,
substantially as described.
Dated this 3rd day of November A.D. 1890.
WILLIAM E. HEIS,
Agent for the Applicants.