Improvements in Machines for Driving Tube Expanders used in the Construction of Water Tube Boilers.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Machines for Driving Tube Expanders used in
the Construction of Water Tube Boilers.
We, ARNOLD FRANK HILLS, of Monkhams, Woodford, in the County of Essex, and
GEORGE SCHOLEY YOUNG, of 50, Clapton Common, in the County of London,
Engineers, do hereby declare the nature of this invention to be as follows:-
Our invention relates to improvements in machinery for conveying and applying
mechanical power for driving tube expanders for expanding the ends of tubes into
the tube plates of water tube boilers for the purpose of making them tight.
In machines of this class as heretofore constructed the power was applied to the
maudrel or other moving part in such a manner that in addition to a torsional force
considerable bending force was applied to the expander resulting in detriment to the
work performed upon the tube whilst being expanded and in the destruction of the
expander itself.
The object of this invention is to provide driving mechanism which shall exert
only a torsional force upon the mandrel or part to be turned, whereby tubes may be
expanded more perfectly and more quickly than heretofore and without detriment to
the expander.
To obtain this result we employ a worm and worm wheel, the former extended
upon the driving shaft and the latter having a shaped hole for revolving the spindle
which loosely fits upon the expander mandrel or part to be revolved, and which can
move freely in and out of the shaped hole in the worm wheel.
We provide a frame for holding the said worm and worm wheel in gear, and also
for receiving a screw which we use for traversing the frame along each row of tubes
to be expanded; we connect the worm driving shaft and traversing screw to the
frame by bearings so extended that they receive the re-action of the twisting force
conveyed to the expander.
We employ supports which we fix to the boiler for supporting the screw and
driving shaft and we make these supports with slots for allowing the worm wheel to
be guided over the various rows of tubes to be expanded. The position of the worm
wheel is thus governed in one direction by the traversing screw and in the other
direction by the cross traverse or twisting in the slots. We make the slots in the
supports straight when the axis of the various rows of tubes are parallel or
approximately parallel to each other. When the axes of the various rows of tubes
are radial or approximately radial to each other we make the slots curved and we
combine supports having straight and curved slots for governing the position of the
worm wheel over tubes with varying axial angles and positions. Instead of slotted
supports suspension links may be used, provided they allow the worm wheel to be
ocated over each of the tubes to be expanded and allow it to be fixed in the required
positions.
:

page_text: In cases where the tubes to be expanded are fitted into small drums or other
shaped vessels, in which there is an opening at each end, we find it convenient to so
connect the driving shaft and traversing screw to the worm wheel frame and also the
traversing screw to the support that the shaft, frame and screw traverse together, and
thus leave the full space in the drum at the opposite end of the supports available
for the workmen to put the expander in and out of the tubes to be expanded. In
cases where the drum into which the tubes are fitted is sufficiently large, we find it
convenient to allow either or both the traversing screw and driving shaft to remain
longitudinally stationary so that the frame with worm and worin wheel traverses
along it or them, and in the case of long drums an additional support may be fitted
for the extended weight of the gear.
We use ordinary methods for driving and reversing the shaft by power, and we
actuate the traversing screw by hand..
Improvements in Machines for Driving Tube Expanders used in
the Construction of Water Tube Boilers.
We, ARNOLD FRANK HILLS, of Monkhams, Woodford, in the County of Essex, and
GEORGE SCHOLEY YOUNG, of 50, Clapton Common, in the County of London,
Engineers, 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 :-
Our invention relates to improvements in machinery for conveying and applying
mechanical power for driving tube expanders for expanding the ends of tubes into
the tube plates of water tube boilers for the purpose of making them tight.
In machines of this class as heretofore constructed the power was applied to the
mandrel or other moving part in such a manner that in addition to a torsional force
considerable bending force was applied to the expander resulting in detriment to the
work performed upon the tube whilst being expanded and in the destruction of the
expander itself.
The object of this invention is to provide a driving mechanism which shall exert
only a torsional force upon the mandrel or part to be turned, whereby tubes may be
expanded more perfectly and more quickly than heretofore and without detriment to
the expander.
In carrying out our invention we employ two parallel shafts or bars projecting
through a suitable support and carrying a frame in which is mounted a worm wheel
engaging with a worm on one of the said shafts which forms a driving shaft, and is
hereinafter referred to as such, the other shaft being provided with screw threads for
moving the frame in the longitudinal direction of the said shafts and being herein-
after referred to as the traversing screw.
The worm wheel has a shaped hole for revolving a spindle which loosely fits upon
the expander mandrel or part to be revolved, and which can move freely in the
shaped hole in the worm wheel.
In cases where the tubes to be expanded are fitted into small drums or other
shaped vessels, in which there is an opening at each end, we find it convenient to so
connect the driving shaft and traversing screw to the worm wheel frame and also the
traversing screw to the support that the driving shaft, frame and traversing screw

page_text: move together, and thus leave the full space in the drum at the opposite end of the
supports available for the workmen to put the expander in and out of the tubes to be
expanded. In cases where the drum into which the tubes are fitted is sufficiently
large, we find it convenient to allow either or both the traversing screw and driving
shaft to remain longitudinally stationary so that the frame with the worm and worm
wheel traverses along it or them, and in the case of long drums an additional support
may be fitted for the extended weight of the gear.
We use ordinary methods for driving and reversing the shaft by power, and we
actuate the traversing screw by hand.
To enable our invention to be fully understood we will describe the same by
reference to the accompanying drawings, in which :-
Figure 1 is a sectional side elevation; and,
Figure 2 is a sectional plan shewing the arrangement of our apparatus specially
adapted for use in small drums or cylinders, that is to say, wherein the driving shaft
and traversing screw move longitudinally with the frame carrying the worm and
worm wheel; and,
Figures 3 and 4 are views similar to Figures 1 and 2 respectively illustrating a
slight modification of this arrangement:
Figures 5 and 6 are respectively an elevation and plan illustrating the arrange-
ment wherein the traversing screw and driving shaft are held against longitudinal
movement the frame carrying the worm and worm wheel being adapted to move
relatively with the said shaft and screw:
Figures 7 and 8 are an elevation and a plan illustrating the arrangement wherein
the driving shaft is adapted to move longitudinally with the frame whilst the
traversing screw remains stationary in So far as longitudinal movement is
concerned :
Figure 9 is a diagram shewing an arrangement of belt gearing for transmitting
motion to the apparatus.
Similar letters of reference indicate corresponding parts in the several figures.
a is the support designed to be fixed to the boiler or the like, b is the traversing
screw and c the driving shaft both of which are carried in the said support and d is
the frame carried upon the said screw and driving shaft.
e is the worm upon the driving shaft c and f is the worm wheel mounted in the
said frame and with which the worm e engages, the said worm wheel having a central
aperture g (which as shown is of square shape) for receiving the spindle designe.[
at one end to be engaged with the mandrel of the tube expander.
With this arrangement it will be obvious that when (the support a being suitably
fixed) rotary notion is imparted to the driving shaft c, for instance through the
medium of a pulley i, rotary motion will be imparted to the wheel f and consequently
also to the spindle h and the tube expander.
As herein before stated the frame d may move in a longitudinal direction with the
traversing screw b and driving shaft c or relatively with both of them or with either
of them. In the arrangement of our invention shewn in Figures 1 and 2 the frame d
is carried upon the ends of the traversing screw and driving shaft and is moved
longitudinally with the latter; in this case both the traversing screw 6 and the
driving shaft c have journals at one end which run in bearings in the frame d and
the traversing screw 6 works through a nut in the support a so that rotary motion
imparted to the said traversing screw causes the longitudinal movement of the
frame d, the driving shaft c at the same time sliding through the support a.
this arrangemement if the driving shaft c is rotated through the medium of a pulley,
such as i, the said shaft is formed with a key-way or channel and a key or feather in
the pulley i engages therewith.
With
The apparatus shewn in the said Figures 1 and 2 is especially adapted for use in
cylinders or vessels of relatively small size in which a workman can from one end of
the vessel reach the tube expander when at the other end it being noticed in the
said arrangement the bearings of the support a through which the traversing screw.
and driving shaft pass project outside the cylinder or vessel.

page_text: In cases where the cylinder or vessel is too long for a workman from one end to
adjust the tube expander at the other end, we arrange for working the expander
from, say, the centre towards the end most remote from that at which the support is
fixed and then, when the tubes of one half have been expanded, we move the support
and expand the tubes of the other half of the cylinder or vessel. With this arrange-
ment in order to afford as much support as possible to the traversing screw and
driving shaft we advantageously arrange that the bearings of the support a carrying
the traversing screw b and driving shaft c shall project into the cylinder or vessel
as shewn in Figures 3 and 4.
In Figures 5 and 6, which illustrate the arrangement wherein the traversing
screw 6 and driving shaft c are held against longitudinal movement whilst the
frame d is adapted to move in relation thereto, the said traversing screw and driving
shaft in addition to being mounted in the support a are also journalled in a bar j the
said screw passing through a nut in the frame d whilst the worm e is provided
with a feather which slides in a key-way or channel in the driving shaft c.
In the arrangement shewn in Figures 7 and 8 the screw b is held against
longitudinal movement as described in the last modification whilst the shaft c is
adapted to move longitudinally in the support a as described by reference to
Figures 1 and 2.
In this modification (Figures 7 and 8) the screw bis provided
with a hand wheel for operating it, the said wheel being made so that it can be
easily moved along the traversing screw and tightened upon the screw for rotating
it. The arrangement described with reference to Figures 7 and 8 is of special
advantage in cases where the apparatus is to be used in conjunction with a drum or
cylinder the man-hole in which is not large enough to allow both the transversing
screw b and the driving shaft c to project through it.
It will be obvious that instead of holding the traversing screw b against longitudinal
movement and moving the shaft c longitudinally the shaft c may be held against
longitudinal movement and the screw b be adapted to move with the frame f.
Any suitable means may be employed for holding the apparatus in position for
work; as shewn in Figures 1 and 2 and also in Figures 3 and 4 the support a is
represented as being pivoted upon a pin fixed to a block m bolted to the flange of
the drum or cylinder the said pin serving as the pivot upon which the support may
be moved from time to time in order to bring the apparatus in position for expanding
another row of holes. As shewn in Figures 5 and 6 the support a is bolted to the
flange of the drum or cylinder whilst the bar j which carries the rear ends of the
traversing screw b and driving shaft c is temporarily secured to a plate or stay n in
the back of the said cylinder.
As shewn in Figures 7 and 8 the support a is clamped in the man-hole whilst the
rear end of the screw b is supported in a boss o on the temporary support n.
In some cases it is advisable to provide the blocks or bars to which the apparatus
is fixed with suitable slots or slides which permit of readily adjusting the position of
the apparatus so as to bring the axis of the worin wheel in alignment with the axes
of the tubes to be expanded. In some cases we combine a swivel movement with a
sliding movement for this purpose.
Motion may be imparted to the apparatus either by hand or by power through the
medium of the pulley i as hereinbefore described. In practice we have found the
apparatus shewn in Figure 9 to work well; this apparatus comprises a pulley p upon
the shop shafting upon which pulley run two belts q, one open and one crossed, the
said two belts running upon two loose pulleys and one fast pulley upon a counter
shaft 8 in a well known manner, in order to cause the said shafts to rotate in one or
the other direction according to which of the belts q or is running upon the fast
pulley. The shaft s has upon it a pulley t from which a belt u runs to the pulley i
upon the driving shaft c of the apparatus. The said belt is advantageously arranged
to run over guide blocks or pulleys v, v on a snatch block anchored in any convenient
position for keeping the band u taut in the different positions to which our apparatus
is placed

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
1. A machine for driving tube expanders wherein a worm wheel is mounted in a
frame carried upon shafts or bars projecting from a suitable support and to
which motion is imparted through the medium of a worm, the said frame being
movable in the longitudinal direction of the said shafts or bars, substantially as
described.
2. In a machine for driving tube expanders the combination of a frame having a
worm wheel mounted upon it, the said frame being carried by two parallel bars
projecting from a suitable support one of which bars has a worm upon it engaging
with the worm wheel and is adapted to be rotated to transmit motion to the worm
wheel and the other of which is formed with a screw thread and serves for traversing
the frame, substantially as described.
3. In a machine for driving tube expanders the combination of two shafts or bars
adapted to slide through a suitable support, a frame carried by the said shafts or bars
at one end, a worm wheel in the frame and a worm upon one of the said shafts
engaging with the worm wheel and adapted to be rotated for imparting rotary
motion to the latter, the other shaft being provided with a screw-thread for moving
the shafts longitudinally in the support, substantially as described.
4. In a machine for driving tube expanders the combination of two parallel shafts
or bars carried in suitable supports one of the said shafts or bars being screw-threaded
whilst the other has a worm wheel sliding upon it, a frame carried by the said shafts
or bars and having mounted in it a worm wheel with which the said worm engages,
the screw thread upon the one bar engaging with a nut in the said frame in such a
manner that the rotation of the screw causes the longitudinal movement of the frame
relatively with the said shafts, substantially as described.
5. In a machine for driving tube expanders the combination of a support, two
shafts or bars projecting from the said support, a frame carried by the said bars and
having mounted in it a worm wheel with which a worm on one of the said shafts or
bars, which forms a driving shaft, engages, the other shaft or bar being formed with
a screw-thread, one of the said shafts or bars being held against longitudinal
movement whilst the other moves with the frame, substantially as described.
6. The improvements in machines for driving tube expanders constructed,
arranged and operating substantially in the manner herein before described and
illustrated in Figures 1 and 2; Figures 3 and 4; Figures 5 and 6 and Figures 7
and 8 of the accompanying drawings.
Dated this 18th dex of Tan 1900
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.