Year: 1887

page_text: Date of Application, 18th Mar., 1887.
Complete Left, 24th Aug., 1887.
Complete Accepted, 27th Sept., 1887.
CHARLES EDWIN HAGGERTY Oakfield Villa, North Ormesby Middlesbrough, Science
Teacher and Engineer, do hereby declare the nature of this invention to be as
follows:-
The invention consists of two pairs of levers and pins attached thereto, so
arranged as to constrain the parts hereinafter referred to, to move in the manner
hereinafter described.
Four boards of equal thickness are hinged together at one edge. Two metal levers,
working on a pin at their centres (which pin is supported by a suitable stand for the
purpose
of carrying the model) are attached at their extremeties, to the centre points,
at the sides, of each of the four boards by means of a pin fixed to the boards at that
point, and carried in slats at the ends of the levers. These levers, when supported at
the centre, constrain the boards, when revolved, to lie, either with their faces together
in one plane, or to stand with their surfaces at right angles to each other.
It is claimed that the model is very strong and durable on account of the attach-
ments of the levers to the boards being at the centre points of the latter. It can be
readily worked to any required position when classes of students are being taught.
Dated this 17th day of March 1887.
CHARLES E. HAGGERTY.

page_text: Working Model of the Co-ordinate Planes to Illustrate the
Principles of Orthographic Projection.
CHARLES EDWIN HAGGERTY Oakfield Villa, North Ormesby, Middlesbrough, Science
Teacher and Engineer, 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 fellowing statement :-
Four levers (or bars), marked in the drawing a, b, c, d, are supported at their
centres, by pins, or bolts, K. and L and are capable of turning freely upon the latter.
In the ends of each lever, slats are provided to receive pins (as at e, f, g, h) which
are fixed to the four boards M, N, O, P, at, or near their centres at the side edges.
These pins form the only attachment, between the boards and the levers by which
they are supported.
The pins, or bolts, L and K pass through any suitable uprights for carrying the
bars and boards, and are screwed at their ends to receive hand wheels I and J which
are used to tighten the bars, and fix them in any position desired.
The boards NP, and MO, are shown in the drawing at right angles to each other,
in which position they represent the "co-ordinate planes" in their real position.
When they are folded flat upon each other, so as to represent a flat sheet of paper,
the pins, at the extremities of each bar, (as E and F) approach each other, and the
slots in the bar are provided to guide the pins, and to admit of the motion referred to.
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. That the levers herein referred to are so made and arranged as to impart to
the boards (or "planes") the exact motion required.
•
2nd. That this arrangement of levers minimises the wear and tear upon the joints,
and the friction upon the working parts.
3rd. That the boards being supported at or near their centres the model is exceed-
ingly strong and durable.
4th. That in consequence of the simplicity of the working parts, the model cannot
readily get out of order.
5th. That the position of the "planes" may be instantly adjusted to any required
position with the greatest facility.