IMPROVEMENTS IN MACHINERY FOR THE MANUFACTURE OF CONICAL SPIRAL SPRINGS, AND IN THE MANUFACTURE OF MANDRILS TO BE EMPLOYED IN SUCH MACHINES
Year: 1879

page_text: LETTERS PATENT to Richard de Soldenhoff, of 10, Ruc Wiering, Louvain, in
A
the Kingdom of Belgium, Civil Engineer, for the Invention of "IMPROVEMENTS
IN MACHINERY FOR THE MANUFACTURE OF CONICAL SPIRAL SPRINGS, AND IN
THE MANUFACTURE OF MANDRILS TO BE EMPLOYED IN SUCH MACHINES."
communication from abroad by Oscar Bihet, Engineer of the "Chemin de Fer
Grand Central Belge," Louvain, in the Kingdom of Belgium.
Sealed the 17th October 1879, and dated the 20th May 1879.
PROVISIONAL SPECIFICATION left by the said Richard de Soldenhoff at the
Office of the Commissioners of Patents on the 20th May 1879.
RICHARD DE SOLDENHOFF, of 10, Rue Wiering, Louvain, in the Kingdom of
Belgium, Civil Engineer. "IMPROVEMENTS IN MACHINERY FOR THE MANUFACTURE
OF CONICAL SPIRAL SPRINGS, AND IN THE MANUFACTURE OF MANDRILS TO BE
EMPLOYED IN SUCH MACHINES." A communication from abroad by Oscar Bihet,
Engineer of the "Chemin de Fer Grand Central Belge," Louvain, in the Kingdom
of Belgium.
The conical springs particularly employed in the rolling stock of railways are
formed of a plate or strip of steel of an elliptical or rectangular section wound in a
spiral form.
The winding of these plates or strips forms one of the most important stages in
the manufacture of the springs.
Besides the system in which the plate or strip is first wound in a volute, then
made to assume the conical form, and finally finished by hand (a very defective
proceeding, in as much as the manual labour produces uncertain results, both in the
spacing of the convolutions and the centreing of the axis). There are several other
modes, principally applied to springs of rectangular section and consisting in the
employment of mandrils. In one of such modes a mandril with a smooth conical
surface is employed. In another mode the mandril has the exact form of the
hollow of the spring when the latter still carries the tang.
This mandril, carried at the end of a shaft and driven in a suitable manner,
receives the plate or strip by the intermittent or continuous action of a pressure
suitably applied, either by the motion of the mandril in the direction of its axis or
by shifting the pressure itself at the same rate as the plate or strip advances along
the mandril, which revolves always in the same place.

page_text: This last mode, which is the simplest, has however several serious disadvantages
resulting from the employment of a long lever, by means of which the necessary
pressure is applied to the plate or strip being wound on the mandril.
In most cases the machine is placed at a distance of from 2 to 3 metres (about
6 ft. Gins. to 9 ft. 9 ins.) from the furnace in which the steel is heated, such distance
causing the cooling of the metal, in order to avoid which it is necessary to greatly
overheat the same and thus risk deteriorating the quality of the spring.
Besides this, the lever requires a workman specially to work it.
The objects to be secured by the first part of this Invention are to obtain an
automatic machine for manufacturing conical springs of whatever section, at the
same time abolishing all necessity for any other workman than the machinist, and
effect the placing of the mandril in the closest possible proximity to the furnace.
The frame of the machine is adapted to fit close to the angle of the heating
furnace, so that the mandril is on a level with the door at a distance not greater
than 50 centimetres (about 1 ft. 8 ins.) therefrom. A shaft is mounted in bearings in
the frame and is fitted with suitable gearing, and carries at one end the mandril,
above which a pressure roller is suspended from a support forming part of the
frame or bolted thereto. This roller is capable of four different movements at the
same time, and the peripheries of the mandril and the roller are made to adapt
themselves to conical springs of any section. The roller is brought in contact with
the plate or strip of metal to be wound and exerts a pressure thereon by means of
a spiral spring, regulated to the kind of work being produced by a pressure nut.
The friction of the plate or strip as it advances causes the roller to revolve on its
shaft. The roller also moves laterally along its shaft, which is smooth and fixed
between the two arms of a forked support. The plate or strip of metal drawn
forward by the rotation of the mandril is caused to mount successively the different
steps thereof and push the pressure roller upwards against the spiral spring. This
spring is adapted to exert a maximum pressure of 450 kilogrammes (about 8 cwt.),
but it can be readily replaced by a stronger or weaker spring, as required. The
pressure roller is thus moved vertically and exerts an increasing pressure on the
plate or strip being wound, such increasing pressure being necessary owing to the
development of the spiral and the cooling of the plate or strip of metal.
The fourth movement of the pressure roller is obtained by the angular displace-
ment which the fork from which it is suspended can assume, such fork being guided
to effect this object within the required limits by the cylindrical form given to a
guiding block and to the surface of the two cheeks of the guides in which the block
slides.
The roller by this means can follow the direction of the plate or strip of metal
obliquely to the axis of the mandril.
Arins connected with the pressure roller's forked support form bearings for a
guide roller, over which the plate or strip is led to the mandril, and which is thus
caused to follow the movements of the pressure roller. The latter revolves in
bearings formed in two arms, between the outer ends of which the plate or strip
passes and is carried along laterally with the pressure roller.
A wedge piece slides freely in a groove formed in the cylindrical end of the
mandril, and carries a hook to receive the end of the plate or strip to be wound on
the mandril. This arrangement abolishes the forge work sometimes required to
wind the first spiral.
By means of a ratchet wheel on the mandril shaft the mandril after each operation
can be brought back with the greatest facility to the position requisite to begin a
new winding.
The small space occupied by the apparatus, which in width is less than the
mandril, permits the latter to be advanced as near as is necessary to the door of
the furnace, and the automatic working of the apparatus, which to start it requires
only a slight turning of the fly-wheel, abolishes all manual labour.
This apparatus makes all the springs with mathematical exactitude.
Its solid construction and simplicity leave no doubt as to its durability and small

page_text: cost of working, and it can be economically applied with the greatest facility to
existing machines.
The advantages obtained over machines previously employed will be made
sufficiently clear by the above description.
Independent of the special application to the manufacture of conical springs the
apparatus may be applied to winding or rolling any kind of articles.
The second part of this Invention relates to the manufacture of step mandrils.
The preparation of such mandrils is a slow and delicate operation. It requires a
deal of careful work on the part of the draughtsman, who must trace the spiral
according to the developed plate or strip, and also on the part of the modeller, who
must make the model in plaster or other suitable material according to this
tracing.
Without using a copying lathe, which is very expensive, the model can only be
made by hand and approximatively. Even when a copying lathe is employed the
template must be modelled by hand.
In order to avoid these disadvantages, of which the loss of time is not the least,
a model plate or strip of any suitable substance, leather for instance, is employed,
such plate or strip representing exactly the plate or strip of the spring to be made,
except that its thickness exceeds that of the spring by the amount of play allowed
to the spirals. This model plate or strip resting flatly at the inclination required
by the theoretical development is attached in a suitable manner upon a table which
slides longitudinally in grooves formed in a frame carrying two fixed supports near
one end.
In these supports are fitted three rollers similar to those of bending machines.
The two lower ones turn on their own axes, whilst the top one can also be vertically
displaced. The journals of this roller are supported in a frame which maintains it
parallel to the plane of the table, at the same time exerting a moderate pressure.
The guides at a certain point of their height are opened out to allow this roller
to be removed. By means of a crank or a pulley keyed on the top roller the
machine is put in motion.
A slit formed in the same roller serves to receive the end of the model plate or
strip.
The whole of this mechanism may be made of wood if the model plate or strip
is of animal or vegetable material.
The rotary motion imparted to the roller governs the travelling motion of the
table by the aid of the plate or strip. The latter pressing on the lower rollers is
bent according to the radii which augment by the successive thickening of the
centre, and as the plate or strip is maintained in the direction of the inclined plane
of the developed spiral, a conical spiral, being a facsimile of the spring which is
thinner, and will therefore allow the necessary play for the spirals, is obtained with
mathematical exactitude.
It is now only necessary to pour into the hollow thus formed the substance to be
employed in making the mould for the mandril.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Richard de Soldenhoff in the Great Seal Patent Office on the 17th
November 1879.
RICHARD DE SOLDENHOFF, of 10, Rue Wiering, Louvain, in the Kingdom of
Belgium, Civil Engineer. "IMPROVEMENTS IN MACHINERY FOR THE MANUFACTURE
OF CONICAL SPIRAL SPRINGS, AND IN THE MANUFACTURE OF MANDRILS TO BE
EMPLOYED IN SUCH MACHINES." A communication from abroad by Oscar Bihet,
Engineer of the "Chemin de Fer Grand Central Belge," Louvain, in the Kingdom
of Belgium.
The conical springs, particularly employed in the rolling stock of railways, are
formed of a plate or strip of steel of an elliptical or rectangular section wound in a
spiral form.
The winding of these plates or strips forms one of the most important stages in
the manufacture of the springs.
Beside the system in which the plate or strip is first wound in a volute, then
made to assume the conical form, and finally finished by hand (a very defective
proceeding, in as much as the manual labour produces uncertain results both in the
spacing of the convolutions and the centreing of the axis), there are several other
modes, principally applied to springs of rectangular section, and consisting in the
employment of mandrils. In one of such modes a mandril with a smooth conical
surface is employed. In another mode the mandril has the exact form of the
hollow of the spring when the latter still carries the tang.
This mandril carried at the end of a shaft and driven in a suitable manner
receives the plate or strip by the intermittent or continuous action of a pressure
suitably applied either by the motion of the mandril in the direction of its axis or
by shifting the pressure itself at the same rate as the plate or strip advances along
the mandril, which revolves always in the same place.
This last mode, which is the simplest, has however several serious disadvantages
resulting from the employment of a long lever, by means of which the necessary
pressure is applied to the plate or strip being wound on the mandril.
In most cases the machine is placed at a distance of from 2 to 3 metres (about
6 ft. 6ins. to 9 ft. 9 ins.) from the furnace in which the steel is heated, such
distance causing the cooling of the metal, in order to avoid which it is necessary to
greatly overheat the same, and thus risk deteriorating the quality of the spring.
Besides this, the lever requires a workman specially to work it.
The objects to be secured by the first part of this Invention are to obtain an
automatic machine for manufacturing conical springs of whatever section, at the
'same time abolishing all necessity for any other workman than the machinist, and
effect the placing of the mandril in the closest possible proximity to the furnace.
The frame of the machine is adapted to fit close to the angle of the heating
furnace, so that the mandril is on a level with the door at a distance not greater
than 50 centimetres (about 1 ft. 8 ins.) therefrom. A shaft is mounted in bearings
in the frame, and is fitted with suitable gearing and carries at one end the mandril,
above which a pressure roller is suspended from a support forming part of the
frame or bolted thereto. This roller is capable of four different movements at the
same time, and the peripheries of the mandril and the roller are made to adapt
themselves to conical springs of any section. The roller is brought in contact with
the plate or strip of metal to be wound, and exerts a pressure thereon by means of
a spiral spring regulated to the kind of work being produced by a pressure nut.
The friction of the plate or strip as it advances causes the roller to revolve on its
shaft. The roller also moves laterally along its shaft, which is smooth and fixed

page_text: between the two arms of a forked support. The plate or strip of metal drawn
forward by the rotation of the mandril is caused to mount successively the different
steps thereof and push the pressure roller upwards against the spiral spring. This
spring is adapted to exert a maximum pressure of 450 kilogrammes (about 8 cwt.),
but it can be readily replaced by a stronger or weaker spring as required. The
pressure roller is thus moved vertically, and exerts an increasing pressure on the
plate or strip being wound, such increasing pressure being necessary, owing to the
developement of the spiral and the cooling of the plate or strip of metal.
The fourth movement of the pressure roller is obtained by the angular displace-
ment which the fork in which it is suspended can assume, such fork being guided
to effect this object within the required limits by the cylindrical form given to a
guiding block and to the surface of the two cheeks of the guides in which the
block slides.
The roller by this means can follow the direction of the plate or strip of metal
obliquely to the axis of the mandril.
Arms connected with the pressure roller's forked support form bearings for a
guide roller, over which the plate or strip is led to the mandril, and which is thus
caused to follow the movements of the pressure roller. The latter revolves in
bearings formed in two arms, between the outer ends of which the plate or strip
passes and is carried along laterally with the pressure roller.
A wedge piece slides freely in a groove formed in the cylindrical end of the
mandril, and carries a hook to receive the end of the plate or strip to be wound on
the mandril. This arrangement abolishes the forge work sometimes required to
wind the first spiral.
By means of a ratchet wheel on the mandril shaft the mandril after each
operation can be brought back with the greatest facility to the position requisite
to begin a new winding.
The small space occupied by the apparatus, which in width is less than the
mandril, permits the latter to be advanced as near as is necessary to the door of
the furnace, and the automatic working of the apparatus, which to start it requires
ouly a slight turning of the fly wheel, abolishes all manual labour.
This apparatus makes all the springs with mathematical exactitude.
Its solid construction and simplicity leaves no doubt as to its durability and
small cost of working, and it can be economically applied with the greatest facility
to existing machines.
The advantages obtained over machines previously employed will be made
sufficiently clear by the above description.
Independent of the special application to the manufacture of conical springs the
apparatus may be applied to winding or rolling any kind of articles.
The second part of this Invention relates to the manufacture of step mandrils.
The preparation of such mandrils is a slow and delicate operation. It requires a deal
of careful work on the part of the draughtsman who must trace the spiral according
to the developed plate or strip, and also on the part of the modeller who must make
the model in plaster or other suitable material according to this tracing.
Without using a copying lathe, which is very expensive, the model can only be
made by hand and approximatively. Even when a copying lathe is employed
the template must be modelled by hand.
In order to avoid these disadvantages, of which the loss of time is not the least,
a model plate or strip of any suitable substance, leather for instance, is employed,
such plate or strip representing exactly the plate or strip of the spring to be made
except that its thickness exceeds that of the spring by the amount of play allowed
to the spirals. This model plate or strip resting Hatly at the inclination or angle
required by the theoretical development is attached in a suitable manner upon a
table which slides longitudinally in grooves formed in a frame carrying two fixed
supports near one end.
In these supports are fitted three rollers similar to those of bending machines

page_text: The two lower ones turn on their own axes whilst the top one can also be vertically
displaced. The journals of this roller are supported in a frame which maintains
it parallel to the plane of the table, at the same time exerting a moderate
pressure.
The guides at a certain point of their height are opened out to allow this roller
to be removed. By means of a crank or a pulley keyed on the top roller the
machine is put in motion.
A slit formed in the same roller serves to receive the end of the model plate or
strip.
The whole of this mechanism may be made of wood if the model plate or strip is
of animal or vegetable material.
The rotary motion imparted to the roller governs the travelling motion of the
table by the aid of the model plate or strip. The latter pressing on the lower
rollers is bent according to the radii which augment by the successive thickening
of the centre, and as the plate or strip is maintained in the direction of the
inclined plane of the developed spiral, a conical spiral being a fac simile of the
spring which is thinner, and will therefore allow the necessary play for the spirals,
is obtained with mathematical exactitude.
It is now only necessary to pour into the hollow thus formed the substance to be
employed in making the model for the mandril.
But in order that this Invention may be more clearly understood, I will proceed
to explain the same by the aid of the accompanying Sheets of Drawings, in which
Fig. 1 is an end view of the improved machine employed for manufacturing conical
spiral springs; Fig. 2 is a side view, and Fig. 3 is a plan of the same.
The frame A of the machine is adapted to fit close to the angle of the heating
furnace so that the mandril B is on a level with the door at a distance not greater
than 50 centimeters (about 1 ft. S ins.) therefrom. The shaft C is mounted in
bearing in the frame A, and carries the wheel D which is driven by the pinion E
on the shaft F. This shaft F carries fast and loose pullies G, G¹, and a fly wheel H.
The shaft C carries at the other end the mandril B above which a pressure roller I is
suspended from the support J forming part of the frame A or bolted thereto. The
roller I is capable of four different movements at the same time, as herein before
described, and the peripheries of the mandril B and the roller I are made to adapt
themselves to conical springs of any section. The roller I is brought in contact
with the plate or strip of metal to be wound and exerts a pressure thereon by
means of the spiral spring K which is regulated to the kind of work to be pro-
duced by the pressure nut L. The friction of the plate or strip as it advances causes
the roller I to revolve on its shaft M. The roller I also moves laterally along its
shaft M which is smooth and fixed between the two arms of the forked support N.
The plate or strip of metal drawn forward by the rotation of the mandril B is caused
to mount successively the different steps thereof and push the pressure roller I
upwards against the spiral spring K.
The fourth movement of the pressure roller I is obtained by the angular dis-
placement which the forked support N in which it is suspended can assume, such
forked support being guided to effect this object within the required limits by the
cylindrical form given to a guiding block O and to the surface of the two cheeks of
the guides P, P¹, in which the block O slides.
The roller I by this means can follow the direction of the plate or strip of metal
obliquely to the axis of the mandril B.
QQ, are arms connected with the pressure roller's support N, and forms bearings
for a guide roller R over which the plate or strip of metal is led to the mandril B,
and which is thus caused to follow the movements of the pressure roller I. The
pressure roller I revolves in bearings formed in two arms S, S, between the outer
ends of which the plate or strip of metal passes and is carried along laterally by
the pressure roller I.
A wedge piece T slides freely in a groove U formed in the cylindrical end of the

page_text: mandril B, and carries a hook to receive the end of the plate or strip of metal to
be wound on the mandril B.
By means of a ratchet wheel W on the mandril shaft C and pawl X the
mandril B after each operation can be brought back with the greatest facility to
the position requisite to begin a new winding.
Fig. 4 shows an end view of the machine to be employed in the manufacture of
step mandrils, which mandrils are used in producing conical spiral springs; Fig. 5
is a side view, and Fig. 6 is a plan of the same.
A model plate or strip A, of any suitable substance, leather for instance, is
employed, such plate or strip representing exactly the plate or strip of the spring
to be made, except that its thickness exceeds that of the spring by the amount of
play allowed to the spirals of the springs. This model plate or strip A resting
flatly at the inclination or angle required by the theoretical development is attached
in a suitable manner as shown, at d upon a table B, which slides longitudinally
in grooves formed in a frame C carrying two fixed supports D, D, near one end.
In the supports D, D, are fitted three rollers a, b, and c, similar to those of
bending machines. The two lower ones, b and c, turn on their own axes whilst
the top one a can also be vertically displaced. The journals of this roller are
supported in a frame E which maintains it parallel to the plane of the table B, at
the same time exerting a moderate pressure.
The guides or supports D, D, at a certain point of their height are opened out
to allow the roller a to be removed. By means of a crank F or a pulley keyed on
the top roller a the machine is put in motion.
A slit G, formed in the roller a, serves to receive the end of the model plate or
strip A.
The rotary motion imparted to the roller a governs the travelling motion of the
table B by the aid of the model plate or strip A, one end of which is attached to
the table at d. The model plate or strip A pressing on the lower rollers b and c
is bent according to the radii which augment by the successive thickening of the
centre, and as the model plate or strip A is maintained in the direction of the
inclined plane of the developed spiral, a conical. spiral, being a fac simile of
the spring to be made, which is thinner, and will therefore allow the necessary play
for the spirals, is obtained with mathematical exactitude.
It is now only necessary to pour into the hollow thus formed the substance to
be employed in making the model for the mandril.
Fig. 7 shows the roller a with the model plate or strip A wound in spirals
thereon.
Having now described the nature of this Invention, and the manner of carrying
the same into effect, I wish it to be understood that what I claim as new is,-
First. The general construction of the improved machine for manufacturing
conical spiral springs, substantially as herein described and shown in the Drawings
on Sheets 1, 2, and 3.
Second. The employment in a machine for manufacturing conical spiral springs
of a pressure roller capable of turning on its shaft, moving horizontally along the
said shaft, moving vertically so as to follow the steps of the mandril, and also
in an angular direction, substantially as herein described and shown in the
Drawings.
Third. The employment of the ratchet wheel and pawl for the purpose of
bringing the mandril back to the starting point after each operation, substantially
as herein described and shown in the Drawings.
Fourth. The general construction of the machine, shown on Sheet 4 of the
Drawings, consisting essentially of a sliding table, upon which a model plate or
strip is attached at one end and at the inclination or angle required for the
theoretical development of the spiral of a mandril, and also of three rollers arranged
similarly as in a bending machine, the top one of which receives in a groove formed
in it the other end of the model plate or strip, and which said top roller is capable

page_text: of moving vertically in its supports, substantially as herein described and shown
in the Drawings.
In witness whereof, I, the said Richard de Soldenhoff, have hereunto set
my hand and seal, this Fifteenth day of November, in the year of our Lord
1870
R. DE SOLDENHOFF. (L.S.)