AN IMPROVEMENT IN TUBE EXPANDERS
Year: 1884

page_text: I, PIERRE PHILLIPPE HURE of Paris in the Republic of France, Engineer, do
hereby declare the nature of my invention for "AN IMPROVEMENT IN TUBE
EXPANDERS," to be as follows:-
This invention relates to the tool known as a tube expander, which consists of
rollers arranged around a tapered mandril, or of tapered rollers arranged around
a cylindrical or tapered mandril. This tool being pressed into the mouth of a
boiler tube, and caused to revolve, expands the mouth of the tube, as is well
known. Now, according to this invention, the rollers are near each end turned
down so as to present a throat of smaller diameter than the roller itself, and an
annular spring is arranged to embrace within it the throats of the several rollers,
so as to press them at each end close against the mandril, while, at the same time,
it leaves them all free to revolve or shift their position on the mandril as they roll
round it. The annular spring may be of various forms, such as those of key
rings, consisting of a plain strip of steel or other suitable elastic metal bent round
to form more than one convolution of a volute or helix; or it may be a round or
rectangular wire helically twisted or corrugated and formed into the shape of a
complete ring. On the inner end of the mandril, a collar is fixed by a nut, which
prevents the rollers from sliding off the mandril, even when it is held vertically.
The outer end of the mandril may be made square to receive a wrench or handle
for turning it, or it may be made with a head having cross holes for inserting a
round pin to turn it as a vice-screw is turned.
Dated this 16th day of June 1881
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings,
London, W.C.

page_text: :
I, PIERRE PHILLIPE HURE of Paris in the Republic of France, Engineer, do
hereby declare the nature of my said invention for "AN IMPROVEMENT IN TUBE
EXPANDERS," 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 the tool known as a tube expander, which consists of
rollers arranged around a taper mandril or of tapered rollers arranged around
a cylindrical or tapered mandril. This tool being pressed into the mouth of a
boiler tube and caused to revolve, expands the mouth of the tube, as is well
known. Now according to this invention, the rollers are, near each end, turned
down so as to present a throat of smaller diameter than the roller itself and an
annular spring is arranged to embrace within it the throats of the several rollers,
so as to press them at each end close against the mandril, while, at the same time,
it leaves them all free to revolve or shift their position on the mandril as they roll
round it. The annular spring may be of various forms, such as those of key-rings,
consisting of a plain strip of steel or other suitable elastic metal bent round to
form more than one convolution of a volute or helix; or it may be a round or
rectangular wire helically twisted or corrugated and formed into the shape of a
complete ring. On the inner end of the mandril a collar is fixed by a nut, which
prevents the rollers from sliding off the mandril, even when it is held vertically.
The outer end of the mandril may be made square to receive a wrench or handle
for turning; or it may be made with a head having crossholes for inserting a round
pin to turn it as a vice-screw is turned.
Fig 1 of the accompanying drawings shews a side view of a tube expander
constructed according to the present invention; Fig. 2 shews a cross section on
line XX fig. 1; fig. 3 shews a modified form of the mandril end. Figs and 5
shew two forms of spirally coiled annular springs of flat steel for holding the rollers;
figs. _6_and_7 shew respectively a front and side view of a helically coiled flat
spring; fig. 8 shews a circular spring of helically twisted wire, and figs. 9 and 10
shew respectively a front and side view of a circular spring of corrugated wire.
The tube expander consists of a group of rollers A having throats A¹ A¹¹ and
arranged round a central conical mandril B upon which they are held by annular
springs C and C₁ fitting into the throats A¹ A¹ and exercising an inward pressure
upon the rollers concentrically with the mandril, with which the rollers are con-
sequently kept in contact. On the smaller end of the mandril is fixed a collar D,
which prevents the rollers from slipping off, and the larger end of the mandril
has a square head d for receiving a crank handle for turning it; or it may
have an enlarged head as at a' fig. 3, with cross holes for the insertion of a bar
for turning.
1
The advantages of the improved tube expander are as follows:-
First. The rollers, although independent of each other, are constantly kept in
*contact with the central mandril by a concentric pressure, thus forming a tool that
can be tarned with one hand.
Second. The elasticity or yielding nature of the springs, permits the rollers to
assume inclined positions relatively to the mandril, according to the direction in
which this is rotated, and to move farther away from the axis thereof, when, for
expanding the end of a tube, it is forced inwards into the same. This inclination
assumed by the rollers causes them, while rolling upon the mandril and the tube,
to move in helical paths and consequently to facilitate the expansion of the tube by

page_text: their advance into the same, while, on turning the mandril in the contrary direction
they are at once released from the tube. The rotation may be effected either in
one direction or the other.
Third. The elasticity of the springs permits of the rollers being placed in any
desired position upon the conical mandril, and consequently the tool can be
adjusted accurately to the diameter of the tube to be operated upon..
Fourth. The collar at the extremity of the smaller end of the mandril, in
preventing the rollers from passing off the same, allows of the tools being used
with vertical tubes.
Fifth. The minimum or maximum diameter of the tubes to be expanded can be
attained without requiring any alteration in the number of the rollers.
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
1, The construction of tube expanders wherein a set of conical or cylindrical
rollers having one or more throats are arranged separate from each other around
a conical mandril against which they are held by one or more circular springs
embracing the throat or throats, substantially as herein described.
2, In combination with the construction of tube expanders referred to in the
preceding claim, the use of a collar at the smaller end of the mandril for preventing
the rollers from passing off the same, substantially as herein described.
BAL
+
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings,
London, W.C.