Means for Illustrating the Principles of Solid Geometry and Model Drawing as Taught in Schools, and for Holding the Necessary Models and Apparatus in any Required Position.
Year: 1887

page_text: Date of Application, 3rd May, 1887
Complete Left, 29th Oct., 1887
Complete Accepted, 29th Nov., 1887
Means for Illustrating the Principles of Solid Geometry and Model
Drawing as Taught in Schools, and for Holding the Necessary
Models and Apparatus in any Required Position.
I, ALEXANDER PARKIN, of 2 Tintern Villas, St. Paul's Road, Sparkbrook,
Birmingham, Government Certificated Teacher, do hereby declare the nature of this
invention to be as follows:-
Two blackboards are hinged together, so that they may be at right angles to each
other and may be held there rigidly by a metal strap and thumbscrew at the side.
These boards represent the Vertical & Horizontal planes, and their intersection is
marked by a white line painted on the boards. When required the two boards can be
brought into one plane and held rigidly by the same metal strap and thumbscrew
mentioned above.
In the Board which forms the Vertical Plane a vertical slot of suitable width and
length is cut.
In this slot works a metal holder clamped at the back with a thumb-
screw, having a shank of suitable length, and furnished with a ball-and-socket joint,
allowing free motion in any direction. The holder has adjustable jaws to grip firmly
the model or other apparatus, which can then be rotated into any required position and
held there by tightening the ball-and-socket joint with a thumbscrew.
This holder will also be made to clamp at the edge of the Black Board instead of
working in a vertical slot in the Board.
The patent is claimed for this apparatus as a whole the separate parts being most of
them well known.
Dated this and dan
1009

page_text: Means for Illustrating the Principles of Solid Geometry and Model
Drawing as Taught in Schools, and for Holding the Necessary
Models and Apparatus in any Required Position.
I, ALEXANDER PARKIN, of 2 Tintern Villas, St. Paul's Road, Sparkbrook,
Birmingham, Government Certificated Teacher 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:-
Two black-boards A B, CD, of any convenient size, are hinged together at E, F,
so that they may be at right angles to each other, and may be held there rigidly by
the metal strap G H, and thumbscrew H at the side. These boards represent the
Vertical and Horizontal Planes, and their intersection is marked by a white line
painted on the lower edge of A B. When required the two boards can be brought
into one plane and held rigidly by the thumbscrew H working in the hole J.
In A Ba vertical slot K is cut. In this slot works a metal holder L M N. The
shank LO passes through the Board and is tightened by the washer and thumb-
screw L. The other end of the shank expands into three arms M, P, Q, forming a
socket in which the ball R can move freely in any plane, and be fixed by the set-
screw S. The two jaws N, V, are hinged at T, opened by the spring U, and closed by
the screw W.
The model or other apparatus is placed between the serrated jaws N Y, secured by
the screw W, and the holder is then rotated in the socket M, P, Q, until the model
is in the desired position, when a turn of the screw S secures it there.
Its plan may then be drawn on CD, and its elevation on A B.
The apparatus will be called "The Projectograph." Figure 3 shows the apparatus
in working order.
my
said
Having now particularly described and ascertained the nature of
invention and in what manner the same is to be performed, I declare that what
I claim is :-
-
1. The Boards and Holder combined form an apparatus which relieves the teacher
of much trouble in holding his model in the required position, while at the same time
it furnishes a surface on which the plans and elevations of objects may be drawn by
L
han nu nunil before they are committed to naner.
1. The Boards and Holder combined form an apparatus which relieves the teacher
of much trouble in holding his model in the required position, while at the same time
it furnishes a surface on which the plans and elevations of objects may be drawn by
teacher or pupil before they are committed to naner.
2. The Holder affords rigidity of grip with great range and facility of adjustment.
3. The Boards can be used as an ordinary Black-board, or folded and placed away
so as to preserve any writing or drawing which is on them from erasure.
Dated this 26th day of October 1887.