Improved Panto-graphic Profiling Instrument for Tunnels, Arches, Bridges, and other Structures.
Year: 1894

page_text: Date of Application, 15th Jan., 1894
Complete Specification Left, 15th Oct., 1894-Accepted, 17th Nov., 1894
PROVISIONAL SPECIFICATION.
Improved Panto-graphic Profiling Instrument for Tunnels, Arches,
Bridges, and other Structures.
FRANK BROOKS HART 49 Old Road Heaton Chapel Manchester Civil Engineer
do hereby declare the nature of this invention to be as follows:-
The instrument hereinafter described is especially adapted for the use of railway
engineers but may be used for other purposes and is constructed for the former
requirement in the following manner :-
The stand or pedestal upon which the measurer or panto-graph proper rests is
formed in the shape of an or an inverted T; the horizontal part or rail gauge
resting on the rails and held in a fixed position, the vertical arm being over the
inner rail when the L pattern is used and over the centre of the "six foot" when
the inverted T pattern is used.
The whole may be in one casting forging or in timber.
The upper extremity of the vertical arm is bored transversely with a pin
(hereinafter called the pedestal pin) fitting.
At the back of the said arm is fixed a plate or board of suitable size at a
convenient distance from the said arm, and the surface of which said board is
parallel to the plane of the pedestal.
The paper or material upon which the section is drawn is fitted on the board.
The plate or board may be fitted rigidly to the pedestal or may work on a swivel
or its equivalent, with or without a clamp.
The panto-graph proper consists of a hollow main shaft with an upper shaft
telescoping into the main shaft.
The lower end of the main shaft fits on the pedestal pin upon which it turns
from side to side.
At a certain determined distance from the pedestal pin another pin (hereinafter
termed No. 1 pin) is fixed in the main shaft.
To No. 1 pin are attached the two ends of a double system of crossing bars
which act as proportional dividers.
At the point where the bars cross the first time is fixed No. 2 pin joining the bars
together through which said No. 2 pin a hole is drilled of suitable diameter to
insert the pencil which draws the section on the paper fixed on the board already
described.
The said pencil fits in the hole loosely and is pressed against the paper by a
spring or its equivalent.
The bars cross & recross a given number of times according to the proportion
required and join and terminate on a pin (hereinafter named No. 3 pin) fixed in the
lower part of the upper shaft.
This No. 3 pin works in a groove reaching from the top to the bottom of the
ower shaft.
A pin passes through each of the bars at the points of intersection and pins join
together the ends of the bars of the two systems.
The centre or intersection pins run in the groove described of the lower shaft,
having collars inside which hold the bars at a fixed distance from the shaft.
The upper shaft is surmounted by a wheel which when the machine is in
operation runs round the structure to be described.
Instead of crossing bars a spring may be used for obtaining the proportion.
The upper shaft may be raised by means of a spring or its equivalent or may be
raised by a cord & pulley wheel fitted to the top of the main shaft.

page_text: The length from the rail level to the pedestal pin is allowed for on the drawing
by scaling off that distance measuring from the centre of the pedestal pin projected
on the paper downwards.
The proportion is found in the following way :-
As the unvariable distance, centre of pedestal pin to centre of No. 1 pin is to
unvariable distance No. 3 pin to top of wheel of upper shaft so is the variable
distance centre of No. 1 pin to centre of No. 2 pin as centre of No. 2 pin is to
centre of No. 3 pin.
Dated this 13th day of January 1894.
COMPLETE SPECIFICATION.
Improved Panto-graphic Profiling Instrument for Tunnels, Arches,
Bridges, and other Structures.
FRANK BROOKS HART 49 Old Road Heaton Chapel Manchester Civil 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 following
statement:-
The instrument hereinafter described is especially adapted for the use of railway
engineers but may be used for other purposes and is constructed for the former
requirement in the following manner :-
The stand or pedestal upon which the measurer or panto-graph proper rests is
formed in the shape of an L or an inverted T ; the horizontal part or rail gauge
resting on the rails and held in a fixed position, the vertical arm being over the
inner rail when the L pattern is used and over the centre of the six foot when the
inverted pattern is used.
The whole may be in one casting forging or in timber.
The upper extremity of the vertical arm is bored transversely with a pin
(hereinafter called the pedestal pin) fitting.
At the back of the said arm is fixed a plate or board of suitable size at a
convenient distance from the said arm and the surface of which said board is
parallel to the plane of the pedestal.
The paper or material upon which the section is drawn is fitted on the board.
The plate or board may be fitted rigidly to the pedestal or may work on a swivel
or its equivalent with or without a clamp.
The panto-graph proper consists of a hollow main shaft with an upper shaft
telescoping into the main shaft.
The lower end of the main shaft fits on the pedestal pin upon which it turns
from side to side.
At a certain determined distance from the pedestal pin another pin (hereinafter
termed No. 1 pin) is fixed in the main shaft.
To No. 1 pin are attached the two ends of a double system of crossing bars
which act as proportional dividers.
At the point where the bars cross the first time is fixed No. 2 pin joining the bars
together through which said No. 2 pin a hole is drilled of suitable diameter to
insert the pencil which draws the section on the paper fixed on the board already
described.
The said pencil fits in the hole loosely and is pressed against the paper by a
spring or its equivalent.
The bars cross and recross a given number of times according to the proportion
required and join and terminate on a pin (hereinafter named No. 3 pin) fixed in the
lower part of the upper shaft.
This No. 3 pin works in a groove reaching from the top to the bottom of the
lower shaft.

page_text: A pin passes through each of the bars at the points of intersection and pins join
together the ends of the bars of the two systems.
The centre or intersection pins run in the groove described of the lower shaft
having collars inside which hold the bars at a fixed distance from the shaft.
The upper shaft is surmounted by a wheel which when the machine is in operation
runs round the structure to be described.
Instead of crossing bars a spring may be used for obtaining the proportion.
The upper shaft may be raised by means of a spring or its equivalent or may be
raised by a cord & pulley wheel fitted to the top of the main shaft.
The length from the rail level to the pedestal pin is allowed for on the drawing
by scaling off that distance measuring from the centre of the pedestal pin projected
on to the paper downwards.
The proportion is found in the following way :-
As the unvariable distance centre of pedestal pin to the centre of No. 1 pin is
to unvariable distance No. 3 pin to the top of the wheel of upper shaft so is the
variable distance centre of No. 1 pin to centre of No. 2 pin to the variable distance
centre of No. 2 pin to the centre of No. 3 pin.
Referring to the drawing a and a' represent the base and vertical arm
respectively of the pedestal.
The upper part of the arm a¹ is bored transversely and fitted with a pin c.
The plate or board d is fixed to the pedestal with stays e and is made parallel
to the plane of the pedestal.
Paper is fitted on the plate or board.
The main shaft f turns upon pin c.
The upper shaft 9 telescopes or slides in shaft f.
Another pin his fixed in shaft fat a determined distance from pin c.
To pin h are attached the two ends of double system of crossing bars i.
At a point where the bars cross the first time a pin k joins the bars together.
Through the said pin a hole is drilled to insert pencil which describes the
drawing on the plate named. The pencil is pressed against the paper by a spring.
The bars i after crossing a given number of times terminate and join on pin m
fitted to the lower part of upper shaft 9.
This pin m works in a groove n reaching from top to bottom of lower shaft ƒ.
A pin p passes through each of the bars at points of intersection.
2°
And pins join ends of bars of the two systems.
Centre or intersection pin p works in the groove n. The said pin has a collar
inside shaft which holds the bars at a fixed distance from the shaft.
The upper shaft 9 is surmounted by a wheels which when the machine is in
operation runs round the arch to be described.
To raise the upper shaft g and consequently elongate the bars vertically a cord
is attached to pin m and passed over pulley wheel t, the other end being held by the
operator who is enabled to raise or lower the upper shaft at will.
The line on plate shews rail level and cu measured vertically represents
distance b¹ to scale.
C
The proportion is as x : x¹ : : y : y².
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The use of the pedestal with vertical arm.
2. The application of unner & lower shafts as described
FRANK BROOKS HART.