"Bows" for Improvements in the Manufacture of Bent Tubes or Cornets and other Wind Musical Instruments, and in Apparatus for use in such Manufacture.
Year: 1891

page_text: Date of Application, 16th Oct., 1891
Complete Specification Left, 2nd June, 1892-Accepted, 23rd July, 1892
PROVISIONAL SPECIFICATION.
"Bows" for
Improvements in the Manufacture of Bent Tubes or
Cornets and other Wind Musical Instruments, and in Apparatus
for use in such Manufacture.
I, DAVID JAMES BLAIKLEY, of 13, Elsworthy Terrace, Primrose Hill, in the
County of Middlesex, Musical Instrument Maker do hereby declare the nature of
this invention to be as follows:-
My invention relates to the manufacture of bent tubes or "bows" for use in
cornets, trombones and other brass wind musical instruments and to apparatus for
use in such manufacture.
Heretofore it has been usual to make such bends or "bows" by one or other of
the following processes viz. :-
(a) By brazing together two halves or pieces stamped to the required shape out
of flat sheet metal. In "bows" made by this method there are two soldered joints,
one along the inner and one along the outer curve of the "bows;" these joints are
liable to unsoundness in the soldering and also to corrosion from the acids in
the breath.
(b) By filling a straight tube with lead or similar material and then bending
the said tube by placing the same upon a suitable former or die and hammering it
to the required shape. This operation is a very tedious one, the tube requiring to
be first partially bent and then carefully hammered to remove the wrinkles or
"cockles" formed in the said tube by the bending thereof and such partial bending
"cockles" having
of the tube and hammering thereof to remove the wrinkles or
to be repeated until the bend or "bow is of the desired shape or configuration.
By this mode of treatment, moreover, it is difficult to make a bent tube or "bow"
with a regular or uniform bore or passage, that is to say, a bore or passage of the
same shape and size in transverse section throughout the length thereof.
It has been proposed to overcome this difficulty by holding the curved piece or
bend between suitable dies and forcing it into shape by means of a sphere of the
required diameter pressed into and through it by means of spheres of somewhat
smaller diameter. The chief defect of this mode of manufacture is that, by reason
of the downward pressure exerted upon the smaller spheres, the metal at the longer
or outer curve of the bend is greatly reduced in thickness as compared with that at
the shorter or inner curve of the bend, and the removal of the wrinkles or
"cockles" at the shorter or inner curve is not effectually ensured.
The first of these methods is that which is chiefly used when bent pieces of sharp
curvature are required and the main object of my invention is to supersede this
method by a more reliable and effective method of manufacture.
By my invention I greatly facilitate the manufacture of the bent tubes usually
termed "bows," and am enabled to make the same very accurately and of
uniform shape and area in transverse section throughout their length, and at the
same time to condense and harden the metal and finish the interior surface of the
tube. My improvements are also advantageously applicable to the manufacture of
the bent or curved tubes used in the pistons of cornets and similar instruments.
In making a bent tube or "bow" according to my said invention, I proceed as
follows, that is to say :-I take a straight tube of the desired diameter, preferably
a weldless tube, and fill the same with lead or similar material in the usual manner,
and cut the same into pieces of the required length. I find it advantageous to cut
the tube so that the ends of the said pieces are bevelled, the side of the tube which
is to form the inner or shorter curve of the bend being shorter than the opposite

page_text: side thereof which is to form the outer or longer curve of the bend. I thus
considerably diminish the liability to wrinkling or "cockling" of the tube in the
bending of the same. This disposition of the metal serves also to minimize the
gathering or thickening of the metal along the line of the short or inner curve.
To bend the pieces cut from the straight tube as aforesaid, I subject them
successively to the action of a number of pairs of dies in a fly-press or the like.
The first pair of these dies effects the partial bending of the tube, and the
succeeding pairs of dies complete the bending thereof, which is thus effected without
the necessity for.hammering the said tube between the bending operations to remove
the wrinkles or "cockles." The dies to be last used are, in some instances, so
formed as to make the end portions of the bent tube, or "bow" parallel to each
other.
The bends thus made are heated to melt out the lead and to anneal the metal of
which the tube is formed, and are then clamped and held firmly between a pair of
accurately shaped dies. While the bend is held between these dies, it is subjected
to the action of a series of tools each consisting of a ball or sphere formed on or
attached to the end of a curved stem fixed in a suitable handle. The spheres of
these tools are of different sizes, that of the finishing tool being of the same
diameter as the bore of the finished tube or "bow," and those of the other tools
being of smaller and smaller diameter, so that, by the successive use of these tools,
the wrinkles or "cockles" will be gradually removed. The spheres of these tools
are forced in succession first into one end and then into the other end of the bent
tube, the curved stém permitting the sphere to be pressed into the said bent tube
to or beyond the middle thereof. A bent tube or "bow" of uniform bore and of
approximately uniform thickness from end to end thereof and having a finished
interior surface, is thus produced. The metal of the tube is, moreover, con-
solidated by compression between the said spheres and the' interior surface of
the dies.
The ends of the bent tube or "bow" thus made are then turned to fit the
ferrules whereby they are connected to the straight tubes of the slide or other
portion or portions of the instrument. For this purpose I find it advantageous to
employ a machine or apparatus comprising a longitudinally movable rotary cutter-
head around which is passed a belt for driving the same. The part about which
this cutter-head rotates is adapted to receive one or other of a series of inter-
changeable mandrels, whereon the ends of the bend or "bow" are successively
placed while being cut. The cutter is attached to the cutter-head in such a
manner that it is adjustable towards and away from the mandrel to suit bends or
"bows" of different diameter. An adjustable rest or support is provided for the
end of the bend or bow which is not being operated upon. A lever is arranged
in combination with the cutter-head for the purpose of moving the latter up to the
work, and a spring is connected with the said lever for effecting its return move-
ment. An adjustable stop is provided for limiting the movement of the lever and
thus regulating the length of the cut. Another lever is, moreover, provided for
keeping the bend or "bow" pressed upon the mandrel and against the said rest or
support. The mandrel is secured in place by means of a set-screw or in any other
convenient manner, so that it can be readily removed, when desired, and replaced
by a larger or smaller mandrel.
Dated this 16th of A

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Bent Tubes or "Bows" for
Cornets and other Wind Musical Instruments, and in Apparatus.
for use in such Manufacture.
I, DAVID JAMES BLAIKLEY, of 13, Elsworthy Terrace, Primrose Hill, in the-
County of Middlesex, Musical Instrument Maker, 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:-—
My invention relates to the manufacture of bent tubes or "bows" for use in
cornets, saxhorns, trombones and other brass wind musical instruments, and to.
apparatus for use in such manufacture.
Heretofore it has been usual to make such bends or "bows" by one or other of
the following processes, viz. :-
(a.) By brazing together two halves or pieces stamped to the required shape out
of flat sheet-metal. In "bows" made by this method, there are two soldered
joints, one along the inner and one along the outer curve of the "bow;" these.
joints are liable to unsoundness in the soldering and also to corrosion from the acids
in the breath.
"
(b.) By filling a straight tube with lead or similar material and then bending
the said tube by placing the same upon a suitable former or die and hammering it
to the required shape. This operation is a very tedious one, the tube requiring to
be first partially bent and then carefully hammered to remove the wrinkles or
"cockles formed in the said tube by the bending thereof, and such partial
bending of the tube and hammering thereof to remove the wrinkles or " cockles
having to be repeated until the bend or "bow" is of the desired shape or con--
figuration. By this mode of treatment, moreover, it is difficult to make a bent
tube or "bow" with a regular or uniform bore or passage, that is to say, a bore.
or passage of the same shape and size in transverse section throughout the length
thereof.
It has been proposed to overcome this difficulty by holding the said curved piece-
or bend between suitable dies and forcing it into shape by means of a sphere of the
required diameter pressed into and through it by means of spheres of somewhat
smaller diameter. The chief defect of this mode of manufacture is that, by reason
of the downward pressure exerted upon the smaller spheres, the metal at the longer
or outer curve of the bend is greatly reduced in thickness as compared with
that at the shorter or inner curve of the bend, and the removal of the wrinkles
or "cockles" at the shorter or inner curve is not effectually ensured.
The first of the methods above mentioned is that which is chiefly used when
bent pieces or "bows" of sharp curvature are required, and the main object of my
invention is to supersede this method by a more reliable and effective method of
manufacture.
By my invention, I greatly facilitate the manufacture of the bent tubes usually
termed "bows," and I am enabled to make the same very accurately and of uniform
shape and area in transverse section throughout their length, and at the same.
time to condense and harden the metal and finish the interior surface of the
tube.
My improvements are also advantageously applicable to the manufacture of the
bent or curved tubes used in the pistons of cornets and similar instruments.
In making a bent tube or "bow" according to my said invention, I proceed as.
follows, that is to say :-I take a straight tube of the desired length and diameter,.
preferably a weldless tube, and, after the same is filled with lead or similar
material in the usual manner, I gradually bend it by subjecting it successively to
the action of several pairs of dies, whereby the bending is effected with but little if
any wrinkling or cockling" of the tube. I then heat the bent tube to melt out.
68

page_text: the lead, and clamp it between accurately formed holding dies, and force through
the said tube as hereinafter described a series of spheres of different diameters
attached to suitable stems provided with handles. I thus finish the bore of the
tube.and make it of. uniform shape and area. in transverse section throughout its
length and, at the same time, condense and. harden-the-metal. I prefer to make the
straight tubes with bevelled ends, so that the side. of the tube-which is to form the
inner or shorter curve of the-bend will be shorter than the opposite side thereof
which is to form the outer or longer curve of the bend. I thus considerably
diminish the liability to wrinkling or "cockling" of the tube in the bending of the
same. This disposition of the metal serves also to minimize the gathering or
thickening of the metal along the line of the short or inner curve.
In the accompanying drawings
Figure 1 is a side-elevation illustrating the manner in which I prefer to form
straight pieces of tube of the required length, bevelled at the ends ready for
bending to the desired shape.
Figure 2 is a side elevation of a short tube ready for bending.
Figure 3 is a front elevation, partly in vertical central section, and
Figure 4 a section on the line a, a, Figure 3, showing one of the pairs of dies
used for bending the tubes.
Figures 5 and 6 are similar views showing another pair of such dies.
Figure 7 is a side elevation, and
Figure 8 a section on the line x, x, Figure 7, showing another pair of dies
adapted for completing the bending of the tube.
Figure 9 is a plan of a pair of clamping dies hereinafter referred to, with the
bent tube in place therein.
Figure 10 is a side elevation of the said clamping dies, showing also a tool
hereinafter described, thrust into the bent tube held between the said dies.
Figure 11 is a plan, and
Figure 12 a side elevation of a machine hereinafter described for turning or
shaping the ends of the bent tube or "bow."
Like letters indicate corresponding parts throughout the drawings.
I find it advantageous, in carrying my said invention into practice, to proceed
as hereinafter set forth, that is to say-I fill a straight tube with lead or similar
material and then cut it into pieces of the required length in the manner indicated
in Figure 1, so that each piece of tube has its ends bevelled, as clearly shown in
Figure 2. Or I form each tube of the required length with bevelled ends by
drawing, after the manner usually adopted in making metallic cartridge-cases or
the like, using, however, a punch formed in such a manner that the closed end of
the drawn tube will be bevelled as required. I then fill the tube with lead or
similar material, and cut it to the required length.
In bending the straight tube a, Figure 2, I subject the same, in a fly-press or the
like, successively to the action of several pairs of dies such as are shown in
Figures 3 to 8. The first pair of these dies b, c, Figures 3 and 4, effects the
partial bending of the piece of tube, and the succeeding pairs of dies complete the
bending thereof, which is thus effected gradually and without the necessity for
hammering the said piece of tube between the bending operations to remove the
wrinkles or cookles."
The tube a is shown by the full lines in Figure 3 partially bent between the
dies b and c, the positions of the upper die band of the tube a before the bending
operation, being shown by the dotted lines. The tube as bent by the dies b, c is
shown by dotted lines in Figure 5, and the full lines show the said tube after it has
been further bent between and by the dies d, e, Figures 5 and 6. The tube as bent
by the dies d, e is then placed between the dies f, g, Figures 7 and 8, and is forced
through the die g to bring it to the required curvature with its end portions
parallel or approximately parallel with each other. In Figure 7, the parts are
shewn in the position which they occupy when the tube is first placed between the
said dies. In Figure 8, the full lines show the position occupied by the parts when

page_text: the tube has been forced nearly through the die g, the dotted lines indicating the
parts in the position shown in Figure 7.
The tube a is thus gradually brought to the required curvature by being sub-
jected to the .action of succeeding pairs of dies, each succeeding pair bringing it
nearer to the curvature required.
The parts of the said dies which come in contact with and bend the tube a,.
are shaped in such a
manner as to preserve the circular transverse section of.
the said tube, and, at the same time, give it a particular curvature in a longitudinal
direction.
The bend or bow thus made is heated to melt out the lead, and to anneal the
metal of which the tube is formed, and the said bend or "bow" is then clamped
and held firmly between a pair of accurately shaped dies such as are shown-
at h, in Figures 9 and 10, by placing and securing the said dies in a vice or the
like. While the bend is held between these dies, it is subjected to the action of a
series of tools, each consisting of a ball or sphere j formed on or attached to the
end of a curved stem j fixed in a suitable handle. The spheres of these tools
are made of different sizes, that of the finishing or last used tool being of the same
size as the bore of the finished tube or "bow," and those of the other tools,.
commencing with that first used, being of larger and larger diameter and
approaching nearer and nearer to the desired diameter of the 'bore of the finished
bend or
"bow," so that, by the successive use of these tools, any wrinkles or
"cockles" that may have been produced will be gradually removed. The spheres
of these tools are forced in succession first into one and then into the other
end of the bent tube, the curved stem permitting the sphere to be pressed
into the said bent tube, to or beyond the middle thereof, as shown at j in
Figure 10.
In the case of bends or "bows" with a curvature considerably less than a semi-
circle, say up to about 120°, the said spheres can be forced completely through the
tubes from one end only.
A bent tube or "bow" of uniform bore and of uniform or approximately uniform,
thickness from end to end thereof, and having smooth or burnished interior and
exterior surfaces is thus produced. The metal of the tube is, moreover, consolidated
and hardened by compression between the said spheres and the interior surface of
the dies.
The bent tube or bow thus made, is then held between another pair of dies or
clamps, similar to those shown in Figures 9 and 10 but of such dimensions as to
leave rather more of the ends of the bow exposed, and its rough edges are trimmed
off by means of a saw. The bend or bow being removed from these clamps, its.
ends are then turned to fit the ferrules whereby they are to be connected to the
straight tubes of the slide or other portion or portions of the instrument. For this
purpose, I find it advantageous to employ the machine or apparatus shown in
Figures 11 and 12. This machine comprises a longitudinally movable rotary
cutter-head, which is mounted upon a stud firmly secured in an upright m¹.
formed on a base-plate m. A cutter is securely attached to the rotary head k,
and a belt, n is passed around the said rotary head for the purpose of driving the
The stud / is adapted to receive one or other of a series of interchangeable.
mandrels whereon the ends of the bend or
"bow a are successively placed and
held while being cut. The cutter is attached to the cutter-head kin such a
manner that it is adjustable towards and away from the axis of the said head to.
suit bends or "bows" of different diameter. An adjustable rest or support p is
provided for the end of the bend or "bow" which is not being operated upon.
shoulder or enlargement on the mandrel determines the position of the end of
the bend or "bow" being operated upon, relatively to the cutter, the bend or
"bow" being kept in position by one end being pressed against the said shoulder **
and the other end against the vertical part pl of the rest or support p by means of
the lever g pivoted at q' to an upright secured to the base-plate
The rest or
support is so constructed as to resist the pressure in a vertical direction produced
same.
"
11.
A

page_text: by the action of the cutter ¹ on the work and to resist also the pressure in a hori-
zontal direction produced by the lever q. The said rest or support is adjustable
vertically in an upright p' in which is secured by a set screw p².
A lever is pivoted at to an upright secured to the base-plate m, and
is connected by pins or studs t with the cutter-head so that the latter may be
moved up to the work by hand. A spring is connected at one end to the
said lever and at its other end to the upright m¹ for the purpose of withdrawing
the said cutter-head from the work when the lever. is released. The pins t
work in slots in the lever r, and are secured in a ring t¹ fitted in a circular
groove in the cutter-head, so as to allow the said cutter-head to be rotated
within it. An adjustable stop u is provided for limiting the motion of the
lever and thus regulating the length of the cut, or the length of the turned
part of the bend or "bow." This stop is secured in an upright u' attached to
the base plate m.
is secured in place by means of a set-screw, or in any other con-
venient manner, so that it may be readily removed, when desired, and replaced by
a larger or smaller mandrel.
The mandrel
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:-
1
First. The herein described improved method of manufacturing bends or "bows"
for cornets, saxhorns, trombones and similar wind musical instruments.
Second. The manufacture of bends or "bows" for wind musical instruments from
straight pieces of tube of the requisite length having bevelled ends, substantially as,
and for the purpose, above specified.
Third. In the manufacture of bends or "bows" for wind musical instruments, the
bending of a straight piece of tube of the requisite length, by subjecting the same,
while filled with lead or similar material, successively to the action of several pairs
of bending dies such as I have hereinabove described.
Fourth. In the manufacture of bends or "bows" for wind musical instruments,
the herein described method of smoothing or burnishing the interior and exterior of
the bent tube and compressing or consolidating the metal thereof, by forcing
successively through the said tube, whilst the same is clamped between accurately
shaped dies, spheres of various diameters attached to stems or handles, as above set
forth.
Fifth. The improved machine constructed substantially as described with
reference to Figures 11 and 12 of the drawings and operating as, and for the
purpose, above specified.
'
Sixth. A bend or "bow" manufactured by my improved process hereinbefore
described, for the purpose specified.
Dated this 2nd day of June 1892.
D. YOUNG & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.