Improvements in Machines for Bending Metal Tubes.
Year: 1893

page_text: Date of Application, 14th Mar., 1893-Accepted, 15th Apr. 1893
COMPLETE SPECIFICATION.
Improvements in Machines for Bending Metal Tubes.
I, REGINALD HADDAN, of the firm of Herbert Haddan & Co., of 18 Buckingham
Street, Strand, W.C., London, Patent Agent, do hereby declare the nature of this
invention a communication to me from abroad by Allan Stirling, of No. .11 West
9th Street, New York, United States of America, Engineer, 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 certain improvements in machines for bending metal
tubes, such as boiler tubes made of wrought iron or of steel. The improvements
which constitute the invention, are pointed out in the following Specification and
claims and illustrated in the accompanying drawing in which,
Figure 1, represents a plan or top view showing the parts in position before the
operation of bending has commenced.
Figure 2, is a side elevation looking in the direction of arrow 1 (Figure 1).
Figure 3, is a side elevation looking in the direction of arrow 2 (Figure 1).
Figure 4, is a plan, or top view, showing the parts in position while the bending
operation is progressing.
In this drawing the letter A designates a frame which forms the bearings for three
arbors BCC On the upper end of the arbor Bis firmly mounted the bending die D
which in the example shown, consists of a segment provided in its periphery with a
semi-circular groove a, the diameter of which corresponds with the diameter of the
tubes to be bent. For tubes of different diameters different bending dies must be
provided. With the bending die is combined a bridle E which serves to secure the
end of the tube to be bent in the semi-circular groove a. In the example shown in the
drawing this bridle consists of an eye-bolt, the shank b of which extends through a
lug c connected to the bending die (Figures 1 and 4) while the eye d of said eye-bolt
is oblong (Figure 3) so that it can embrace the end of the tube to be bent and also
a lipe which projects from the front edge of the bending die and serves as a support
for the front end of the tube. The shank 6 of the eye-bolt is provided with a
screw thread and with a nut fand by screwing up this nut, the end of the tube can
be firmly clamped on the bending die. In order to prevent the end of the tube
from being crushed, a plug g may be inserted. On the arbor C is eccentrically
If this
mounted the retaining die El and a handle F serves to turn the arbor C.
handle is turned to the position shown in Fig. 1, the retaining die E' is moved away
from the bending die D so that the tube can be conveniently introduced between
the two dies and if the handle F is moved to the position shown in Figure 4 the
retaining die is brought to bear upon the tube so as to hold the same in the
semi-circular groove a of the bending die. The retaining die is provided in its
circumference with a semi-circular groove h (Figure 3) corresponding in its
diameter to the semi-circular groove a in the bending die so that when the two dies
are brought together, the grooves a and embrace the tube. In the example
shown in the drawing, the retaining die E¹ is mounted loosely upon a wrist pin i
which is secured eccentrically in a disk j mounted firmly upon the arbor C and the
handle F is firmly mounted upon the outer end of eccentric wrist pin i.
Behind the retaining die E¹ is situated the stop G to prevent the tube from
flapping as the operation of bending progresses. In the example represented by the
drawing, I have shown a cylinder containing a piston to which motion is imparted
by hydraulic pressure. The piston rod I carries a rack bar J which engages a
toothed segment K mounted on the arbor B.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a machine for bending tubes, the combination with the bending die D,
of the bridle E, and means for imparting to the bending die a rotary motion,
substantially as described.
2. In a machine for bending tubes, the combination with the bending die D,
and the bridle E, of the retaining die E', and means for imparting to the bending
die a rotary motion, substantially as described.
3. In a machine for bending tubes, the combination with the bending die D
and the bridle E of the stop G, and means for imparting to the bending die a
rotary motion, substantially as described.
4. In a machine for bending tubes, the combination with the bending die D, of
the bridle E, having an oblong eye d, a lip e, projecting from the bending die into
this oblong eye and means for imparting to the bending die a rotary motion,
substantially as described.
5. In a machine for bending tubes, the combination with the bending die D,
and the bridle E, of a roller E¹ mounted eccentrically on an arbor C, a handle for
turning this arbor and means for imparting to the bending die a rotary motion,
substantially as described.
1000
Dated
MY CITTA
Herbert Haddan & Co.,
R. HADDAN.
18, Buckingham Street, Strand, London, Agents for Applicant.