Improved Machine for Bending Tubes.
Year: 1890

page_text: Date of Application, 19th June, 1890
Complete Specification Left, 6th Feb., 1891-Accepted, 21st Mar., 1891
PROVISIONAL SPECIFICATION.
Improved Machine for Bending Tubes.
I, JOHN LAIDLAW, of the firm of Watson, Laidlaw & Co., of 98, Dundas Street,
Kingston, Glasgow, Engineers, do hereby declare the nature of this invention to be
as follows:-
This invention which relates to improvements in machines for bending tubes, has
for its object to provide a machine which will bend the tubes without the necessity
of filling the tubes to preserve the proper section of its bore.
I attain this object by means of the mechanism hereinafter described. Two
rollers are connected together and moveable in a slot between two fixed rollers.
These four rollers are hollowed or grooved so as to suit the diameter of the tube to
be bent. The two rollers which are connected together touch at their circum-
ferences, and the hollowed out groove in the two rollers form a closed curve which
will just enclose the tube to be bent and prevent it getting out of shape in the
process of bending. The two fixed rollers are driven by any convenient mechanism,
and one of them is geared through an intermediate toothed wheel with one of the
two moveable rollers. The position of the moveable rollers in the slot is adjusted
to suit the curve to which the tube is to be bent. Instead of having the two rollers
which are connected together moveable, I may have these fixed, and the other two
moveable in slots.
Dated this 18th day of June 1890.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicant's Agents.
COMPLETE SPECIFICATION.
Improved Machine for Bending Tubes.
I. JOHN LAIDLAW, of the firm of Watson, Laidlaw & Company, of 98, Dundas
Street, Kingston, Glasgow, North Britain, Engineers, 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, which relates to improvements in machines for bending tubes, has
for its object to provide a machine which will bend the tubes without the necessity
of filling the tubes to preserve the proper section of its bore.
attain this object by means of the mechanism hereinafter described. Two
rollers are connected together and moveable in a slot between two fixed rollers.
These four rollers are hollowed or grooved so as to suit the diameter of the tube to
be bent. The two rollers which are connected together touch at their circum-
ferences, and the hollowed-out groove in the two rollers form a closed curve which
will just enclose the tube to be bent, and prevent it getting out of shape in the
process of bending. The two fixed rollers are driven by any convenient mechanism,
and one of them is geared through an intermediate toothed-wheel with one of the
two moveable rollers. The position of the moveable rollers in the slot is adjusted
to suit the curve to which the tube is to be bent. Instead of having the two
rollers which are connected together moveable, I may have these fixed, and the
other two moveable in slots.
In order that my invention may be properly understood and readily carried into
effect I have hereunto appended two explanatory sheets of drawings, in the several
figures of which corresponding parts are marked with the same letters of reference.
Figure 1 is an elevation, and Figure 2 a plan of the bending machine.

page_text: Referring to Figures 1 and 2, A is the machine frame or table. In this table a
slot B B is formed, in which a slide or block C C, carrying the two moveable
rollers D, E, can be moved by means of the following arrangement:-A rod or
spindle is attached to the block C C, and has a screw formed on its outer end.
This screwed part works in a nut, having a bevel wheel G formed on it. The
nut is turned by the hand-wheel H and bevel pinion I. By turning the handle in
one direction or the other the slide or block CC with the rollers D, E can be
moved to one end or other of the slot. The two fixed rollers are shown at J and K.
In each of the four rollers a circumferential groove is formed which will enclose
one half of the circumference of the tube to be bent, so that when two of the rollers
are brought together they will completely enclose the tube. The rollers are driven
by the mechanism now to be described. The first motion shaft L is driven in one
direction or the other by the well-known arrangement of two belts M, M, two
loose pulleys N, N', and one fast pulley 0, or by its equivalent. Motion is
communicated to a second shaft P by the toothed-wheels Q, R. The shaft P has
two bevel pinions 'S and T which gear with the bevel wheels U and V keyed to the
axis of the fixed bending rollers J and K. Motion is communicated to the roller D
from the roller J by means of the toothed wheels W, X, Y, as shown in
Sheets 1 and 2, and motion is communicated to the roller E by means of toothed-
wheels, (one of which is shown in dotted lines at d) underneath the table or
frame A.
When the machine is to be used for bending tubes the slide or block C C is
adjusted to the proper position to give the required bend to the tube and the be
is introduced past the roller into the hollow formed by the grooves of the
rollers D and E. The act of bending the tube tends to oval its cross section at
right angles to the curve of the bend, but the grooves in the rollers being formed
to fit the original cross section of the tube, prevents the ovalling. Consequently
there is a pressure between the tube and the rollers, and by this action the
rollers D and E by their revolution draw the tube along.
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 machine for bending tubes, substantially as described.
2. In a machine for bending tubes, the arrangement of two rollers moveable
together, which in combination with two fixed rollers give the necessary curvature
to the tube while passing through the machine, substantially as described and
illustrated on the drawings.
3. In a machine for bending tubes, the arrangement of two moveable rollers held
together in a sliding frame with their circumferences touching, each having a
circumferential groove which together completely enclose the tube and prevent it
getting out of shape during the process of bending.
4. In a machine for bending tubes, the arrangement for driving the moveable
rollers from one of the fixed rollers by toothed-wheels and a jointed link, sub-
stantially as described, and illustrated on the accompanying drawings.
5. In a machine for bending tubes, the arrangement of gearing by which all the
bending rollers are driven together, at a uniform surface velocity, substantially as
described and illustrated on the accompanying drawings.
Dated this 5th day of February 1891.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicant's Agents.