Improvements in Tube Expanders.
Year: 1893

page_text: Date of Application, 14th July, 1893-Accepted, 19th Aug., 1893
COMPLETE SPECIFICATION.
Improvements in Tube Expanders.
I, WILLIAM BOAZ, of 29 West India Dock Road, in the County of London.
Engineer, 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, reference being had to the accompanying drawings and to
the letters and figures marked thereon, that is to say :-
My invention relates to improvements in tube expanders, whereby a greater
range of expansion is obtained than with expanders at present in use.
According to my invention, the body of the expander consists of a steel, iron,
or other metal disc, or annular plate, formed with radial grooves in which carriages,
furnished with rollers, are free to slide. Suitable means, (such as a cam-plate, or
a disc provided with curved slots), are provided, whereby the carriages receive.a
simultaneous movement either of separation or of bringing together, and when a
tapered and faced mandrel, or a mandrel having a flat portion, is introduced
between the carriages, these are caused to separate and the rollers to bear evenly
against the interior of the tube and to so expand the same.
And in order that my invention may be readily understood, I proceed to describe
the same fully with reference to the accompanying drawings, in which:-
. Fig. 1 is an elevation of my improved tube expander, with the mandrel
inserted.
Figs. 2 and 3 are face views thereof, Fig. 2 showing it when used for small
tubes, and Fig. 3 when used for large ones.
:
Figs. 4 and 5 (Sheet 2) are back views of the body of the expander, showing
the cam plate or slotted dise in the position it occupies when the carriages are in
their separated, and in their approached, positions, respectively.
Fig. 6 (Sheet 1) is a side elevation of one of the carriages detached from the
body of the expander; and
Fig. 7 (Sheet 1) shows a section of the same.
A is the body of the expander which consists of a steel or other metal disc, or
annular plate, in which are formed, say, three radial grooves of dovetail or other
suitable form. In these grooves are adjusted carriages B, carrying rollers C, which
are free to revolve on pivots D. These carriages also carry bearing blocks b for
abutting against the tube plate. a is a recess in the body A in which is located
the cam plate F, or plate formed with curved slots F', corresponding in number to
the carriages employed. These carriages are provided with studs or headed
pins F, which pass through the slots in the cam plate and through radial slots F
in the body; and by means of these pins the carriages are guided and their simul-
taneous movement ensured, they being brought together when first applying the
expander to a tube. The studs or headed pins above mentioned also serve the
purpose of retaining the cam plate in its position in the recess. are buttons or
studs fixed on the cam plate, and by means of which such cam piate can be turned
when it be desired to bring the carriages together, or to separate them previously
to inserting the expander into the tube.
:
E is the mandrel which is tapered as usual, but is faced or flattened at E'
along its length. It is passed through the centre of the body A, that is to say
between the carriages, and bears against the rollers C. Thus, on the mandrel
being introduced, the carriages are caused to simultaneously separate, and, in so
doing, bring their rollers to bear against the tube and so expand its end. Each
time the faced or flattened portion E of the mandrel comes into contact with the
rollers C, a self-feeding and a self-releasing action are produced, and thus the
.

page_text: expansion of the tube can be quickly effected without the use of a hammer,
the mandrel being revolved by a
66 tommy or lever passed through the eye. E².
"
may provide interchangeable carriages, carrying larger rollers, so that tubes of
large diameter may be readily acted upon.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same may be performed, I declare that what
I claim is
1. A tube expander having its body formed with radial grooves in which work
carriages provided with rollers for bearing against and expanding the tube, and
with means for effecting the separation or the bringing together of such carriages,
substantially as described.
2. A tube expander having its body formed with radial grooves wherein carriages,
provided with bearing rollers, are adapted to be advanced or retired by a cam
plate, or plate having curved slots, in which the said carriages engage, substantially
as described and illustrated.
3. In tube expanders, the use of a tapered mandrel faced or provided with a
flat portion extending along its length, substantially as and for the purposes set
forth.
4. My improvements in tube expanders, substantially as described and shown
with reference to the annexed drawings.
71
T 1
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 6, Victoria Street, Nottingham,
Agent for the Applicant.