An Improvement in Tube Expanders.
Year: 1891

page_text: Date of Application, 11th Apr., 1891
Complete Specification Left, 8th Aug., 1891-Accepted. 31st Oct., 1891
PROVISIONAL SPECIFICATION.
An Improvement in Tube Expanders.
I, JOHN MCKAY, of Victoria Avenue, Whitley, in the County of
Northumberland, Engineer, do hereby declare the nature of this invention to be as
follows:
My invention relates to the rollers of tube expanders, of any of the ordinary
types now in use, and consists in forming in the surfaces of the rollers a groove or
grooves running lengthwise (preferably 3 in number and parallel with the axis)
such groove or grooves extending in length somewhat beyond the thickness of the
tube plate.
The effect of the groove or grooves is that, when the rollers are revolved by the
"mandril" within the tube, a rib is left projecting from the internal surface of the
tube at each groove, which ribs are pressed, by the plain portion of the following
roller or rollers, again "flush" with the internal surface of the tube which, by the
process, is expanded into the tube plate more efficiently, and with less strain, than
with smooth rollers.
All there rollers may be grooved or only one or two of them, in the former case
one revolution of the rollers, when 3 grooves are in each, will form 9 ribs which
will each in turn be pressed flush" with the internal surface as the rollers revolve.
The grooves will be so shaped with rounded edges that no cutting or injury to the
tube can occur.
In the case of tubes screwed into the tube plates, or stay tubes, the effect of the
rollers upon the raised ribs will be to give great additional tightness to the threads
on the tube within the tapped plate, without tending to spread out the tube
lengthwise.
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T. J. DANSON,
By L. W., per F. B.
COMPLETE SPECIFICATION.
An Improvement in Tube Expanders.
I, JOHN MCKAY, of Victoria Avenue, Whitley, in the County of
Northumberland, Engineer, do hereby declare the nature of said invention and in
what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
My invention relates to the rollers of tube expanders, of any of the ordinary
types now in use, and consists in forming in the surfaces of the rollers a groove or
grooves running lengthwise (preferably parallel with the axis) such groove or
grooves extending in length somewhat beyond the thickness of the tube plate.
"
The effect of the groove or grooves is that, when the rollers are revolved by the
"mandril within the tube, a rib is left projecting from the internal surface of the
tube at each groove, which ribs are pressed by the plain portion of the following
roller or rollers, again "flush" with the internal surface of the tube which, by the
process, is expanded into the tube plate more efficiently and with less strain, than
with smooth rollers.
All three rollers may be grooved or only one, or two, of them, in the former case
one revolution of the rollers, when 3 grooves are in each, will form 9 ribs which
will each in turn be pressed "flush" with the internal surface as the rollers revolve
by the smooth portions thereof.

page_text: DESCRIPTION OF DRAWINGS.
On the accompanying drawing I shew my invention in one form with one grooved
roller A. having 9 grooves and two other plain rollers B and C.
Fig. 1 is a view looking on the end of a tube and
Fig. 2 is a sectional side view through the line X-X' on Fig. 1.
A, B and C are the three rollers, D is the tapered mandril the other portions
of the expander not being shewn as they form no part of my invention. E is the
tube being expanded into the tube plate F. The grooved roller A has started at
the point X, Fig. 1, and has travelled in the direction of the arrows through ths
of the internal circumference of the tube having left in its progress 9 ridges or ribs
thereon at each revolution but the following plain roller B has partly pressed these
ridges or ribs into the substance of the tube the third plain roller C completing the
process and leaving the internal surface of the tube perfectly smooth the tube
having now been expanded in the tube plate and any further expansion is effected
by repeating the process until the requisite degree of expansion, depending upon
the working pressure, is secured.
The grooves in the roller A are preferably cut from end to end to facilitate the
introduction of the mandril but they may be cut so as to stop short of the ends also
the number of the grooves may be less or more than 9 and the roller B, or both B
and C, may be grooved in such relation to each other that the ridges or ribs formed
by the leading roller A shall be pressed down by the plain surface of the succeeding
roller which will in its turn raise other ridges or ribs, preferably of less projection,
which will in turn be pressed down by the following roller.
The grooves are shewn parallel with the axis of the roller but I reserve the
right to use them at an angle as shewn by Fig. 3 which may in some cases be
preferable.
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 :-
In tube expanders the use of one or more grooved rollers or a combination of
grooved and plain rollers the grooves running lengthwise, cither parallel with the
axis or inclined thereto, for the purpose of facilitating the expansion of the tube
into the tube plate by the mode of operation set forth and in one form illustrated.
T. J. DANSON, F. Inst. I.A.,
2, St. Nicholas Buildings, Newcastle-upon-Tyne, Agent for Applicant.