A JOINTED MANDRIL FOR TUBE COILING AND BENDING
Year: 1885

page_text: I, GEORGE ROUND of Bearwood Road, Smethwick in the county of Stafford
Manufacturers foreman do hereby declare the nature of my invention for
A JOINTED MANDRIL FOR TUBE COILING AND BENDING to be as follows:-
This invention consists in the construction and arrangement of a mandril having
a portion of its length consisting of a number of jointed links whereon tubes may
be bent or coiled, such mandril being used in conjunction with such other ordinary
mechanism as may be necessary. In describing this mandril and the mode of using
it more minutely I may say that I take a bar of suitable section according to the
interior of the tube which is to be bent or coiled. At one end of this bar I shape
it to receive a link, and to this link I attach another link, and so on until the
desired length is attained, making it in fact a bar or mandril having a chain of
links attached to one end. The other end of the bar or mandril is made so that it
can be secured at will to some fixture, but the chain end is brought near to a block
or other body, such as for instance the face plate of a lathe, or barrel in a lathe, or
other suitable mechanism to which motion can be applied either by power or by
hand, such block or other body being of a suitable diameter and shape for the work
required.
The tube being threaded on to the mandril, with one end of the said tube
generally being left extended a little beyond the end of the chain; the said
extended end of the tube is secured to the block or body, face plate or barrel, to
which latter motion is then applied, and the tube is thus drawn off the mandril in
a coiled or bent shape corresponding to the shape of the block, body, face plate, or
barrel, the jointed links enabling that part of the mandril to yield in shape to the
revolving or moving block, and at the same time offering such a support to the
inside of the tube that preserves its shape, and obviates crumpling to a greater or
less degree.
By these means I am enabled to bend either continuous circles, involute or
other spirals, angles, or other forms desired, according to the shape of the block
used.
This mandril may be made of iron, steel, or other metal, the form of the joints,
and form of links being selected according to best suit the work in hand.

page_text: I GEORGE ROUND of Bearwood Road, Smethwick, in the county of Stafford,
Manufacturers foreman, do hereby declare the nature of my invention for A
JOINTED MANDRIL FOR TUBE COILING AND BENDING, and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :—
:
This invention consists in the construction and arrangement of a mandril having
a portion of its.length consisting of a number of jointed links whereon and whereby
tubes may be bent or coiled, such mandril being used in conjunction with such other
ordinary mechanism as may be necessary. In describing this mandril and a mode
of using it more minutely I may say that I take a bar of suitable section according
to the interior of the tube which is to be bent or coiled. One end of this bar I
shape to receive a link, and to this link I attach another link, and so on until the
desired length is attained, making it in fact a bar or mandril having a chain of
links attached to one end.
The other end of the bar or mandril is made so that it can be secured at will
to some fixture, but the chain end is brought near to a block or other body in
connection with other suitable mechanism to which motion can be applied.
I will now proceed to further describe this my invention by the assistance of the
accompanying sheet of drawings which has figures and letters of reference thereon.
Fig. 1 is an elevation of one form in which the jointed mandril may be made.
Fig. 2 shews a part sectional plan of Fig. 1. Fig. 3 shews a section of Fig. 1 upon
line A-B.
Fig. 4 shews a section of Fig. I upon line C-D. The straight part a, may be
made of greater or lesser length, but is generally about 18 inches long, as its length
may be extended to any required distance by means of a smaller rod b, screwed
thereinto similarly as shewn.
Any required number of links c, c1, c2, c 3, c 4, c 5, c 6, are then secured to each
other, either by rivetting as shewn or, instead of being connected up together by
rivets they may be connected by screws if desired. The end link c7 may be
made rounded at the end as shewn, or, the mandril may terminate with one of
the ordinary links, as in most cases it would be immaterial. Sufficient room is
provided at d, so that the jointed mandril may be beet to the desired angle or circle
to which the tube is to be bent. The surfaces at e, & f, are more or less rounded or
curved, as then, the tension of the upper part of the tube (when being bent), and
the compression of the lower part, take place at, or nearly so, points opposite to each
other, viz upon or near the middle of the length of the link.
These jointed mandrils may be made up of a variety of forms of links, either
with joint pius, rivets, or screws, or, the joint may in some cases be formed as part
of the link itself, after the manner of Fig. 11 & 12. A few forms in which these
links may be made for instance, are shewn at Figs. 5, 6, & 7, Figs. 8 & 9, Figs. 10,
& Fig. 11 &12. . In each and all cases the object being to produce a jointed mandril,
which shall be sufficiently strong and flexible to bend over a desired angle or curve;
upon which metal tubes shall be bent and shaped.

page_text: In some instances I may reduce the friction between the tube and the mandril
when in operation, by introducing rollers as shewn at o Fig. 5 & 6. These rollers
may be either inserted in the top of the mandril only, or in the top and bottom (as
shewn by dotted lines) and may consist of one or more of such rollers in each or
any number of links.
Although I have shewn the mandril as being round to suit round tubes, still
I wish it to be understood that I may make it of any section to suit other tubes.
Fig. 13, shews a method in which this my jointed mandril may be used for
bending tubes, a, c, c, c, being the jointed mandril, b, the rod to extend its length,
g a suitable holding or gripping device to prevent forward movement of mandril,
h the tube to be bent, which has been threaded on to the mandril, k is the block
upon which a coil is made and corresponding approximately to the inside diameter
or form of the desired coil, is a face plate or wheel or other suitable mechanism
to which the block may be secured, and to which the end of the tube projecting to
or beyond the end of the mandril is fastened.
Having passed the tube to a little beyond the end of the mandril and secured it
to the face plate l, similarly as shewn at m, motion is then given to the plate or
wheel in the direction of the arrows, when the tube is drawn off the mandril on
to the block k, and thereby assuming a similar form and size to the said block; the
jointed links enabling that part of the mandril to yield in shape to the revolving or
moving block, and at the same time offering such a support to the inside of the
tube that preserves its shape, and obviates crumpling, creasing, or bulging to a
greater or less degree.
By these means I am enabled to bend either continuous circles, involute or other
spirals, angles, or other forms desired, as the blocks & Fig. 13, may be varied in size
and shape to suit the various forms in which it is desired that the tubes shall be
bent, and the necessary mechanism adapted accordingly.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
A jointed mandril for the purpose of facilitating the bending or coiling of tubes
substantially as hereinstated and shewn upon the drawings, or any mere modifi-
cation of a jointed mandril for such purposes.
Dated this 50th 1 T 100%