Improvements in Machines for Bending Metals.
Year: 1893

page_text: Date of Application, 7th Oct., 1893-Accepted, 2nd Dec., 1893
COMPLETE SPECIFICATION.
[Communicated from abroad by HENRY LEFEVRE, of 195, Faubourg St. Martin,
Paris, in the Republic of France, Mechanician.]
Improvements in Machines for Bending Metals.
I, HENRY HARRIS LAKE, of the Firm of Haseltine Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, 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 machines for bending metals.
A machine constructed according to my said invention is designed for bending
rolled hollow or flat metals by successively curving the linear elements and
preserving the curves obtained.
The improved machine comprises a bending tool which seizes the articles to be
curved, such as a tube or the like, between rolls and is guided in a path identical
with the line of bending to be obtained (spiral, wave line, serpentine or the like),
thus curving the said article, while auxiliary bending tools, which are carried away
in the same path by the principal tool, and by the intervention of traction parts,
keep the portions already bent of the article in course of being manufactured in its
form and hold the same in its position, and at any desired distance towards the
rear, thus preventing this article from losing the bend which it has already received
while the principal tool continues to advance.
In the accompanying drawings,
Figure 1 is an elevation of my machine;
Figure 2 is a vertical section taken through its middle.
Figure 3 represents a front view of a spiral guide or path of the bending part
in combination with the parts which cause it to move and with the so-called
auxiliary tools serving to prevent the deformation of the end of the tube already bent.
Figure 4 shows an outer view of a bending tool principally designed to obtain
plane bends, such as spirals, wave lines and the like.
Figure 5 shows a vertical central section taken through this bending tool.
Figure 6 is a plan of the guide of a bending tool specially adapted for bending
longitudinally (wave lines).
Figure 7 illustrates an outer view of a bending tool specially serving to produce
serpentine tubes.
Figure 8 is a vertical section taken through this tool.
Figures 9 and 10 show the form and arrangement of the bending rolls employed
for bending any figured iron.
Figure 11 represents another arrangement of the machine for making plane curves,
with horizontal guides.
Figure 12 is a plan of the arrangement shown in Figure 11.
Figure 13 represents a front view of a length of tube held in the principal bending
tool and its two auxiliaries.
Figure 14 represents an arrangement of the machine which is based on the same
principle and is specially designed for making cylindrical, conical and other
serpentines and similar articles.
The bending tool comprises a truck presenting the form of a transverse piece H
and the two extremities J of which are guided upon rails c, Figures 2, 3 and 6,
whose form or path corresponds to that of the bend to be given to the article to be
manufactured. If this article has to be bent according to a plane spiral the rails
or guides e forming projections upon the plate C, Figures 2 and 3, constitute
similar spirals, so that the bending tool which advances in these guides will curve

page_text: the article which it holds between its rolls, thus bending it in accordance with the
path formed by the guides, the said article not being able to be carried away in the
movement, whilst its portions which have already been bent are constantly kept in
their form and held in their position and are consequently protected against any
deformation.
When the article is to be bent in any desired manner in the direction of its length,
for example according to a wave line, the rails or guides c must have the form
represented in .Figure 6.
The extremities of the tool embrace the three free sides of these rails or guides c
by three rolls bbb1, Figures 2 and 4.
Figures 1 and 2 show the arrangement of the machine when it is specially
designed for curving a pipe in a plane spiral. The extremity of the pipe to be bent
is passed between the rolls I of the tool H and is fixed upon the periphery of a
disc K keyed upon an axis D so as not to be able to turn.
The two arms J of the bending tool are guided in the longitudinal slots J' of
levers E, in which this tool H is moved during the rotation upon the fixed axis D ;
being moreover guided by its two extremities in the spiral path it will describe a
spiral as it slides in the slots J¹ of the levers E, that is to say it will during this
movement curve the tube which passes between its rolls according to a spiral.
This pipe is compelled to bend, for the disc K prevents any axial displacement of
the same.
When in lieu of presenting a spiral the article to be manufactured must be
curved only in the direction of its length, namely according to an elongated
line like that represented in Figure 6, I displace the tool H by means of two
endless traction parts, for instance endless chains or their equivalents, along
guides, Figure 6. These parts e, Figure 1, are guided upon a certain number
of rolls R which cause them to assume approximately the desired form for the
bending, namely that of the rails c Figure 6, in order that the direction of the
force of traction may always coincide as much as possible with that of the move-
ment of the tool H, that is to say perpendicular to the position of the latter.
For enabling the rolls R to be displaced in accordance with the form of the
tube or other article to be curved, that is to say for enabling the traction part
to be guided in accordance with any desired form, I provide in the frame A of
the machine numerous slots a receiving the roll Rand enabling them to be
displaced, which rolls also serve in part for fixing the guides c, Figures 2 and 6.
This fixing is effected by means of bolts B, Figure 2, which pass through
the said slots. It is evident, that in this mode of operation the portions
already bent by the forward movement of the tool H have to be supported and
kept in their positions in order to avoid, during the subsequent forward movement
of this tool, any action at the rear tending to destroy the bend already obtained.
For this purpose a series of trucks termed auxiliary bending tools P, Figure 3,
are attached to the tool H, the aforesaid tools being connected by chains Q
with each other and with the principal tool H.
Each of these trucks carries two rolls which embrace the bent article in the same
manner as do the rolls of the tool. As these trucks are moreover guided upon the
rails c, Figures 2 and 6, thus occupying positions which correspond exactly to the
bending already effected, they prevent the tube, at the points where they are
placed, from losing the bend it has received, by reason of a counter-action of the
tool H. In this manner I can prevent, to any distance rearwards of the tool, any
deformation of the article in course of manufacture, for I can attach any number
of these trucks to each other.
It is clear that the article treated in the before described manner need not
absolutely be a pipe but may be metallic bars of any form; in this case the bending
rolls and the guide rolls only change in accordance with the profile of the article
to be made. Figures 9 and 10 represent each a pair of rolls designed respectively
for bending L iron and T-iron. This process may be employed in the same
manner for bending flat iron.

page_text: When it is desired to give tubes the form of serpentines, that is to say helices,
it will be advantageous to arrange the tool as represented in Figure 7.
Two pairs of bending rolls f, fare arranged in a nut S and placed unsymmetrically
one relatively to the other according to the pitch of the helix which is to be
obtained. Two rods T, Figure 8, passing through holes in the nut S and carried
away by the plates U during their rotation upon the fixed central axis D, transmit
to the nut S a rotary movement, by reason of which this nut is displaced at the
same time in the direction of the axis upon its screw threaded rod X, Figure 7.
The pitch of this screw-threaded rod corresponds exactly to the pitch of the
serpentine which is to be obtained and which results from the rotation of the nut S.
When the machine is to serve only for one or the other of these kinds of work,
certain parts may be dispensed with. For example if the bending is to take place
only longitudinally, Figure 6, the central shaft D and its corresponding parts
become useless.
If on the other hand it is intended to manufacture only serpentines the traction
parts e and their numerous guide rolls R become superfluous, the movement having
principally to be transmitted to the central parts US which are still necessary.
Movement is transmitted from the shaft O through the medium of toothed
wheels N N N N to the shaft M which actuates the traction parts e passing
round the rolls R. When necessary I obtain from the pulleys L the movement
communicated to the parts which turn upon the central shaft D. Upon this shaft D
are mounted the loose wheels G, Figures 2 and 7, which through the medium of
endless chains or their equivalents d, receive the movement of the pulleys L and
transmit it to the levers E, Figures 2 and 3, or to the tool S, Figure 7, through the
medium of the plates U, these parts having to make a rotary movement round the
fixed axis D, during the bending as hereinbefore explained. The supports L' for
the pulleys L are adjustable by means of screws for enabling the traction parts e
and d to be stretched.
The machine represented in Figures 11, 12 and 13, designed for bending plane
curves, operates exactly on the same principles as that which has just been
described; the arrangement of its parts alone differs.
This machine comprises a lower frame A carrying interiorly the transmitting
device and serving as a stand for a fixed disc C toothed at its periphery and
possessing radial grooves.
A vertical axis D actuates a series of toothed bevel wheels with a reversing
gear, which wheels impart circular movement in one or the other direction to the
bending tools.
The bending tool H slides longitudinally in the lever E which turns upon the
axis D owing to the rotation of the pinion Z upon the teeth of the disc C. This
first bending tool H being attached by chains Q to the auxiliary bending tools P,
which are displaced longitudinally upon the levers particulated upon the axis D,
carries the said bending tools with it.
The operation takes place on the guides c precisely in the same manner as in the
machine represented in the preceding figures.
Without departing from the principle of my invention I may also fix the lever H
and turn the disc C. The result obtained will be exactly the same.
The machine represented in vertical section in Figure 14 is specially designed
for bending cylindrical, conical and other serpentines or similar articles.
It comprises a frame A' to which a plate A" with a hollow central column A
is secured. Upon this frame is mounted a plate C' having convergent grooves and
rolls moving upon circular rail X through the medium of a toothed crown forming
one piece with the plate C₁ the said plate being operated by a pinion.
Upon the column A is mounted the holder C for the helicoidal guides, made
cylindrical or conical according to the form of the serpentine to be manufactured.
This guide holder is provided with longitudinal grooves by means of which I fix
upon it the guides cl in the form of helices.
The column A11 is traversed by the shaft D¹ which receives its movement by

page_text: toothed wheels and has secured at its top the lever E. This lever is connected
with the plate C₁ by the link E¹ carrying the principal bending tool H¹.
The levers p which are attached to the same plate C¹ by the links p" carrying
the bending tools P₁are loose upon the shaft D', the tools P₁ being connected by
chains to the tool H. For the sake of clearness of the drawing I have not shown
in Figure 14 the lever pl of the lever E', but in reality they follow each other,
because their bending tools are united by short chains. The shaft O' with a
reversing gear receives its movement of the general transmitting device and com-
municates it to the plate C', the shaft D' and consequently to the lever E' and the
bending tool H which turn together at an equal velocity. This tool H¹ conducted
by the guides e¹ follows regularly, by sliding along the link E, the curve which it
is desired to give to the tube. The levers are caused to follow the movement
by means of chains, as herein before explained, or by any other suitable device.
For bending a tube I slide the tube prepared at its extremity into the bending
tools, this extremity is fixed to the guide holder C.
As soon as movement is communicated, the bending tools act upon the tube to
bend it according to the curves indicated by the guides.
When I desire to manufacture serpentines of various dimensions, either
cylindrical or conical, it is sufficient to replace the guide holder (" by one which
is adapted for the type of serpentine to be produced.
Similarly as for the machine before described I may render the plate C', lever E'
and bending tool H' stationary the guide holder C" being adapted to turn.
With these machines I may simultaneously effect the bending and polishing, or
the dressing and polishing of the cold tubes coming from the welding rollers.
I may also combine the parts of the machine for treating several articles at the
same time.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me
by my foreign correspondent, I declare that what I claim is :-
First. A machine for bending metallic bars, figured iron, tubes and the like, in
which the bending tool H H or S, which seizes the article to be manufactured
between bending rolls, is guided by a path c or c¹ similar to that of the line of
bending to be obtained, such as a spiral, wave line, helix or the like, and thus
curves the said article, while auxiliary tools P or P', which are carried away by the
principal tool H, H' or S in the same path c or c¹ by means of traction parts, keep
that part of the article which has already been bent in its form and hold it in its
position, thus preventing it during the forward movement of the principal tool
from losing the bend which it has already received.
Second. A machine for bending metallic bars, figured iron, tubes and the like,
which has a path c or c¹ turning upon an axis at the same time as the article to be
manufactured, in combination with bending tools which cannot turn but are
displaced longitudinally upon the levers carrying the tools.
Dated this 7th day of October 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.