A New or Improved Blackboard and Sheet-mounting Apparatus.
Year: 1889

page_text: Date of Application, 5th Nov., 1889
Complete Specification Left, 5th Aug., 1890-Accented. 20th Sept.
1890
PROVISIONAL SPECIFICATION.
A New or Improved Blackboard and Sheet-mounting Apparatus.
I AMBROSE JESSE GRAYSTON of St. Paul Street, Worcester, Schoolmaster do hereby
declare the nature of this invention to be as follows:-
At
The objects are (1) To provide in convenient form and small compass a large
superficial area which being coated with suitable composition may be serviceable for
writing, drawing, &c. (2) To enable a large number of sheets printed or otherwise, to
be massed together in convenient form and small compass. In carrying out this inven-
tion a frame of wood or other material is constructed and at- any desired position
thereon or in relation thereto two rollers are placed. To these rollers are attached
the ends of a sheet of calico, cloth, or other material one end being attached to each
roller. The rollers are revolved and the sheet attached thereto moved and kept in
tension by bands, wheels, springs or other contrivances automatic or otherwise.
the back of the whole or a part of the exposed portion or portions of the sheet, a board
or boards may be placed so that the exposed portion or portions may serve the purpose
of an ordinary rigid blackboard: To ease and guide the sheet additional rollers are
placed at convenient positions their number and relative bearing depending on the
positions of the rollers to which the sheet is attached, on the shape of the frame, and on the
use of one or both sides of the sheet. The rollers which ease and guide the sheet are
of ordinary make but those to which the sheet is attached may be of special con-
struction for keeping the sheet in tension when an equal number of revolutions are
made with varying diameters.
Dated this 2nd day of Novamhan 1000
I
COMPLETE SPECIFICATION.
A New or Improved Blackboard and Sheet-mounting Apparatus.
I AMBROSE JESSE GRAYSTON of Saint Paul's Street, Worcester, Schoolmaster 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:-
This invention relates to a new kind of blackboard, or apparatus with a surface from
which writing may be easily obliterated, by means of which an increased area over
the present form of blackboard may be obtained without materially increasing the
dimensions of the same.
It also refers, either separately or conjointly, to an apparatus for mounting printed
and other sheets. *
The invention is carried out in the following manner, reference being had to the
annexed drawings: :-
Fig. 1 shows in perspective the arrangement of rollers suitably supported in the
frame and carrying the material for supplying the writing surface of the blackboard
or upon which the printed and other sheets may be mounted.
Figs. 2 and 2 show in sectional side elevation modifications of the arrangement of
rollers by which one side only of the material is used.
Fig. 3. shows in sectional side elevation an alternative modification of the
invention.
Fig. 4. shows in transverse section an arrangement with perpendicular rollers.
Fig. 5. shows a detached view of an arrangement for actuating the rollers a when
these rollers are at a short distance from each other, by means of a bandle ƒ and
cog-wheels g, g', g². The ends of the spindles 9 of the rollers a (which rollers must
[Price 6d1

page_text: be constructed as shown in Fig. 7 for keeping the material in tension when an equal
number of revolutions of the rollers a are made with varying diameters) are prolonged
a sufficient distance to allow a cog-wheel g¹ to be attached to each spindle or roller and
gear with an intermediary cog-wheel attached to which is the handle f which on
being revolved operates the rollers a and exposes a fresh portion or fresh portions of
the material.
Fig. 6. shows an arrangement for working the rollers a when these rollers are close
together but ordinary rollers only are used.
Fig. 7 shows a section of a portion of the roller used with the cog-wheels in
Fig. 6.
i, spiral spring working in roller a (a portion of which is hollow) and attached to
the saine at m.
j, rod around which the spring is wound and to which it is attached at n.
k, pulley or cog-wheel attached to the rod j by the pin l, or otherwise.
The rollers being set after the fashion of ordinary spring window blind rollers the
material thrown off by one roller and not taken up by the other is re-wound by a
backward motion of its own roller. By this arrangement the sheet is kept in tension
although equal revolutions of rollers are made with varying diameters.
c, material for writing upon or upon which the sheets are mounted.
a, a, drums or rollers to which the material c is attached.
1, rollers for supporting and guiding the material c.
d, framing which forms a support for the material c.
e, casing within which the rollers are supported in any suitable manner at a¹,
and b¹.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
-
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"blackboard,"
1. The improved construction, arrangement and combination of a
consisting of a suitable casing within which a suitable number of rollers a and b are
arranged, the material having a prepared writing surface being attached to and wound
around the rollers a supported and guided by the rollers 6 substantially as described.
2. In blackboards the combined arrangement substantially as shown by which a fresh
writing surface is exposed by the action of rollers operated by cog-wheels and a bandle,
.or other suitable device.
3. The combination of rollers in a case, substantially as shewn by means of which
a sheet actuated and guided by such rollers may be used on both sides for mounting
sheets and other purposes.
4. The combination of rollers and cog-wheels or other suitable device, substantially
as described, by means of which a sheet attached to two of the rollers is wound and
re-wound and kept in tension, when equal revolutions of the rollers are made with
varying diameters.
T: and dow of Art 1800
.A. J. GRAYSTON.