Improvements in and connected with Machine Tools or Apparatus for Preparing Test and similar Pieces from Metal or other Material.
Year: 1889

page_text: Date of Application, 9th Nov., 1889—Accepted, 3rd May, 1890
COMPLETE SPECIFICATION.
Improvements in and connected with Machine Tools or Apparatus
for Preparing Test and similar Pieces from Metal or other
Material.
I, JOHN ARMSTRONG SNOWDON of Thirlwell House, Wolsingham in the County
of Durham, Engineer, do hereby declare the nature of the said invention and in what
mannerthe same is to be performed to be particularly described and ascertained in
and by the following statement, reference being had to the accompanying three
sheets of drawings, and to the letters and figures marked thereon, that is to say :-
The invention relatos partly to improvements in a machine tool designed by me
and known to engineers as Snowdon's shaping, screwing and bolt making machine,
and partly to improved machinery or apparatus which may be used either in con-
nection with that machine or with certain other machine tools. The chief object
of the said improvements is to facilitate the preparation of test pieces in metal or
other material, but such improvements are also applicable to the preparation of
similar pieces for other purposes.
In the drawings hereto annexed Figure 1 is an elevation of one of my said
shaping, screwing and bolt making machines with part of my present improve-
ments applied thereto, Figure 2 is a plan of summe partly in section, Figure 3 is
a front elevation of the sliding block marked 14 in Figures 1 and 2; its cover
plate, shown separately in Figure 4, being removed to enable the parts beneath
to be more clearly seen.
The machine consists, as is well known, of a cast iron bed A having bolted
thereto or cast therewith a headstock B which carries a hollow traversing mandril C
and an ordinary lathe spindle D the latter driven by cone pulleys E which also
communicate rotary motion to the traversing mandril O by gearing. On the bed A
is also mounted a bracket F which carries a block 14 which can be traversed
transversely across the bed A into various positions, and is provided with cutters
for turning spindles or bolts, screwing dies for forming threads thereon, and
cutters for cutting off the said spindles or bolts. There is also usually pro-
vided, in connection with the lathe spindle D, a rising and falling table G provided
with slides or slide rests on its upper surface as may be required for the particular
class of work to be performed. Such is the general character of the machine
which I propose to apply to the purpose of preparing test piecos in order to
cheapen the cost of such pieces, which have heretofore been prepared in lathes
and other tools at very considerable expense.
I will now proceed to describe my various improvements in the said machine
to adapt it to the above mentioned purpose and in apparatus for the said purpose
applicablo to that and to certain other machine tools.
One improvement consists in the employment of a friction clutch in connection
with the spindle D for the purpose of connecting the same with, or disconnecting
it from the hollow traversing mandril C at pleasure, so that the latter may be
stopped while the spindle D continues to work, an arrangement not hitherto used
in the machine but desirable in some cases.
On the spindle D is keyed the speed cone E and on the same spindle is placed
a sleeve which is free to turn thereon. On the sleeve 4. either cast along with
it or keyed to it, is a toothed pinion 5 which gears with a spur wheel 9 fixed on
the same shaft as the pinion 10 which gears with the spur wheel 11, giving
motion to the hollow mandril C on the end of which is secured the chuck 12.
6 is a clutch sleeve sliding on the sleeve 4 but caused to turn therewith by a
feather. The clutch sleeve 6 is shaped conically at one end so as to act on the
tail of a lever 7 when forced to the right in Figure 2 and to force the said
lever 7 into a wedge shaped groove formed by the ends of a split ring 8 which

page_text: is turned to fit casily into the interior of the speed cone E. When the lever 7
is forced into the said wedge-shaped groove the ring 8 is expanded and presses
tightly against the internal surface of the recess in the speed cone in which it is
contained so as to give motion to the sleeve 4 and pinion 5 and thereby through
the gearing 9, 10, 11 to the hollow mandril C. When the clutch sleeve 6 is moved
to the left in Figure 2, the lever 7 is released, the ring & contracts and is freed
from the speed cone E, and the sleeve 4, pinion 5, gearing 9, 10, 11 and the
hollow mandril Care stopped. The clutch sleeve 6 is moved to the right or left
by means of the handle and connecting rod 13, a similar handle heing placed at
the opposite side of the machine if necessary.
Another improvement relates to the sliding block 14 which moves transversely
in the bracket F and carries the cutters intended to act upon the piece of metal
to be turned. The improvement consists of the following arrangements:-15 is
a V piece and 16 is a straight steady piece both inserted in the block 14 for
the purpose of keeping the rough piece of metal held in the chuck 12 steady and
central while it is being turned to the necessary diameter by the cutter 17. This
cutter 17 is an improvement on those heretofore used in this machine, because it
is of much greater length, so that when it is required to be ground it can easily
be held in the hand during that operation. And by reason of an improvement
in the cover plato 14× of the block 14 the said cutter 17 can be removed and
replaced in much less time than heretofore.
This coverplate 14* has heretofore been made in two parts jointed together
at W W, XX (see Fig. 4) by which arrangement that part of the lower plate
covers the slot containing the cutter 17, thereby rendering it necessary to remove
the seven screws J and to slack back the two screws K in order to release the
lower part of the cover plate before the cutter 17 can be removed from its sint.
I still make the cover plate in two parts jointed together at W W, but instead
of jointing them at ✗X I leave that part attached to the upper portion of the
cover plate, and so shape its edge that it joins against the front of the cutter 17
while the corresponding edge of the lower portion of the cover plate joins against
the back of the cutter 17, thus leaving an open space clear of the said cutter,
through which the latter can be taken out, without removing the covering plate
at all, by simply slacking back or removing the screw 19 which passes through
a cross bar L one end of which bears on the cutter 17 and the other end on the
stealy piece 16 in order to hold both in place. The position of the cutter 17 is
regulated or adjusted by means of the set screw 18 which acts on the shoulder 17b
of the cutter 17. To save measuring the length of the piece when turning I
place a bridle piece 20 in the turning hole in the block 14, which bridle piece is
held in position by the covering plate, the lengths are regulated by means of
screws of suitable length screwed into the bridle piece, as shown at 20. When
the test piece is turned to the proper length its end comes against the screw 20°
and can go no further, it is then withdrawn from the turning hole and the sliding
block 14 is moved so as to bring the hole 21 opposite the end of the turned
piece which latter is then passed into the said hole by the traversing mandril,
and the cutter 21ª is brought up to cut off the piece. When the distances
to turn and cut off the piece do not come within the scope of the bridle
piece 20 I use a hinged bar 20 having two steel pointers 22 and 23 connected
therewith, the said pointers are movable in all directions and can be set to any
length within the scope of the machine. The pointer 22 marks the length to
which the piece is to be turned, and the pointer 23 the length to which it is to
be cut off, after which the bar 20 with its pointers can be turned up against the
covering plate of the block 14 to allow the chuck 12, holding the test piece, to
advance the required distance towards the block 14.
Another improvement relates to modifications of the machine to enable it to deal
with test pieces of square, rectangular or irregular section. Heretofore such pieces
have been turned in a lathe, the corners being sometimes previously planed away to
produce an approximately round piece before the turning operation is performed.

page_text: Such operations are costly and slow, and the angular corners cause an unequal
jolting action which breaks the turning tools, strains the lathe, and often does other
damage, and a series of cuts have to be taken over the piece before it can be brought
to the true circular section. In order to obviate the loss of time and inconveniences
above mentioned I arrange an apparatus shown in Figures 5, 6, 7 and 8 which takes
the place of the ordinary cutter block 14 shown in Figures 1, 2 and 3. Figure 5 is
an elevation, Figure 6 a longitudinal section, Figure 7 a transverse section and
Figure 8 a section on line X Z of Figure 5.
His a frame or tool holder of cast iron, steel or other suitable metal in which are
fitted three cutters 26, 27, 28, the cutting edges of which project into the conical
hole or die 29 made in a block of hardened steel 30, being arranged in such manner
as to operate singly or collectively according to circumstances. The framework H
may be adapted to receive more cutters than three if required or desirable. It will
now be understood that if a piece of material of irregular section is secured at one
end in the chuck 12 of the traversing mandril C (Figures 1 and 2) its other end may
be forced into the conical die 29 and will be acted on by the cutters 26, 27, 28,
which lay in slots cut through the sides of the said die. The cutter 27 is placed at a
lower depth in the die than the cutter 26 and does not come into action on the piece
of material until the cutter 26 has taken off a large proportion of the material that has
to be removed, when it comes into play and removes the remainder. When necessary
the cutter 28 may take a share in the work of turning, although as shown it is
intended for dividing the test piece into two lengths, one for a tensile and the other
for a bending test. The sliding brackets 31 and 32, Figure 6, are use! when the
test piece, from the nature of the casting forging or otherwise, is short, and the whole
of the available material is required to form the test piece. Supposing that the
piece of material has been turned as far as the holding chuck 12 will allow, it is
then removed from the chuck and turned round end for end so that the turned portion
is gripped centrally in the chuck and the latter, with the piece secured in it, is then
advanced so as to bring the rough unturned end into the conical die 29, the sliding
brackets 31, 32 are then moved towards the centre close up to the turned portion and
are clamped in position, thus forming steadying bearings which hold the test piece
concentric no matter how irregular in shape the said piece may have been. The
turning of the rough end can now proceed and thus the turning of the whole length
can be completed so as to make the piece suitable for a bending test piece. The
brackets 31, 32 can be moved to one side out of the way when not required.
To turn a tensile test piece in the apparatus shown in Figures to S the cutters 26
and 27 are replaced by the cutters 33 and 34, Figure 6, and a tool holder of the
kind shown at 35 in Figures 5 and 6 is used for both cutters 33 and 34 to enable
them to be moved forward or drawn back at pleasure. 36 is a forked piece to take
the end strain of the cutters 26, 27 being applicable to both cutters in ordinary work,
its advantage is that it holds the cutiers down by the action of the centre screw 37
at the same time that it keeps the cutter from being forced back from its work in
cases where the cone headed screw 38 might allow it to slip. It also allows the
cutter to be quickly disengaged by dropping out of the way to enable the cutter to
be withdrawn out of its seat.
When the cutters 33, 34 are placed in the positions occupied by cutters 26, 27,
Figure 6, they are used as follows:-The test piece having been reduced to a round
section, and the cutter 33 having been secured in a tool holder of the same kind as
that shown at 35 the said cutter 33 is pressed forward by the screw 39, until the test
piece is cut to the required form to suit the grips of the testing machine. The test
piece is then traversed outwards or upwards as the case may be, the cutter reducing it
in the middle of its length as shown. The cutter 34 is next pressed forward and
completes the opposite end of the test piece which may or may not be cut off by the
cutter.
In some cases I use an extra pair of sliding steadiers immediately below the conical
die block 30. The steadiers 31, 32 may also be replaced by others acting close to the
top of the conical dic. When the apparatus shown in Figures 5 to S is to be used,

page_text: the sliding block 14 shown in Figures 1 and 2 is removed and the.frame 11 takes its
place. The apparatus shown in Figures 5 to 8 may be used on a lathe or on a drilling
or screwing machine when required.
1
Another improvement relates to the production of square test pieces. For this
purpose I employ the tools shown in Figures 9 to 14. Figures 9, 10 and 11 are
respectively an elevation, section and plan of a cast, or forged steel bracket 40
with a pair of vertical jaws 41, 42. The test piece 43 is forced up against these jaws
by means of four screws 44 with collars 45 and spherical washers 46 acting against
two moveable jaws 47. The object of the spherical washers is to accommodate the
jaws 47 to the gripping of other than square sections. The bracket is bolted to the
bed of a planing or shaping machine and the test piece 43 being firmly gripped by
means of the aforesaid screws 44, two planing tools 48 can be employed, one on
each side of the piece as shown in Figure 10. V grooves are cut in the jaws to
hold round pieces that require squaring.
Figures 12, 13 and 14 show the same apparatus with the test piece being
operated upon by two circular milling cutters 49 which may be attached to the
cone mandril D of one of my aforesaid shaping, screwing and bolt making
machines as shown in Figure 2, the bracket 40 with the test piece 43 secured
thereto being bolted on the sliding table 50 by which the necessary movement, is
given to enable the cutters 49 to operate in squaring the test piece. This operation
can be carried on at one side of the machine, Figures 1 and 2, while the other side
of the same machine is engaged in preparing round pieces. The bracket above
described may also be employed for preparing square test pieces in a lathe or in a
milling, drilling or other suitable machine tool if required.
When it is required to obtain a test piece from a casting, forging or dead-head
in which it is not possible or convenient to employ planing or slotting tools, the
operation becomes very expensive. In order to effect this object easily and
economically employ the tool shown in Figures 15 to 20 which forms another
part of my improvements. Figure 15 is a section of a hollow cylindrical tool 51
with a number of cutters 52 formed at its lower end as shown, each cutter being
made to take its proper share of the work, and in such manner that it can easily bo
ground from time to time. In Figures 15 and 16 the cutter portion 53 of the tool
is shown made from a piece of steel separate from the main body 51 of the tool, but
preferably that device is only to be resorted to after the tool, originally made in one
piece, has worn too short to make the proper length of test piece. The separate
cutting portion 53 is fixed to the body 1 by a double clutch-like arrangement and
four screws 54. A hole 55 is drilled through the centre of the tool, the upper
portion of the said hole being made smaller than the lower for the purpose of giving
strength to the tool, and depth of thread for the screw 55° and pad piece 56 (see
Figure 15). Into this hole is fitted a hardened steel centre 57. For the purpose of
lubricating the cutters when working in a vertical position, a cup 58 is secured to the
tool or made in one piece therewith, a hole 59 forming a communication between
the said cup and the interior of the tool, and a groove is cut down the side of the
centre 57 to allow water or other lubricating material to pass to the cutters.
Figures 18 and 19 the cutter portion 53 is shown connected to the body 51 by being
screwed direct thereto.
In
60 in Figures 15, 17, 19 and 20 represents a block of steel or other material being
operated upon by the tool to obtain a test piece. This operation is carried out as
follows: A centre is punched in the material 60 to be operated upon in such a
position that the periphery of the hollow cylindrical tool 51 projects somewhat beyond
the face of the material; that is to say, the annular groove made by the tool that
would otherwise form a complete circle is about of the circumference short of being
a complete circle. By this simple means the cuttings are got rid of at each revolution
and the rate of penetration is thereby greatly increased. The centre 57 is allowed
to project beyond the face of the cutting tool and to press rather lightly in the centre
punch hole. The screw 55* is forced rather tightly against the centre 57 to allow
the tool 51 to slide down over it as the latter is forced down by the feeding

page_text: apparatus of the machine until the cutters have entered the material to the
extent of a quarter of an inch or thereabouts, when the said centre 57 may be
removed and the work proceed without it. In some cases a short centre about
14 inches long, held by a screw in a similar manner, may be employed, which
screw may be slacked when the cutters have entered the material and the said
centre may remain in the interior of the tool until the test piece is cut
out. To remove the test piece, all that is necessary is to either drill the annular hole
entirely through the material or to nick the pin, or part not quite drilled through,
with a chisel when the test piece is easily removed. The tool shown in Figures 15
to 20 may be used in a lathe or drilling machine.
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 :-
:-
First For the purpose of preparing test or other similar pieces in metal or other
material the use of the machine tool known as Snowdon's shaping, screwing and bolt
making machine arranged and adapted as hereinbefore described and illustrated in
the drawings hereto annexed.
Second The combination of a friction clutch with the lathe spindle D of the
machine tool shown in Figures 1 and 2 of the drawings for the purpose of connecting
the traversing mandril & with the said spindle or for disconnecting it therefrom
substantially as herein before described, and 'illustrated in the said Figures 1 and 2 of
the drawings hereto annexed.
Third The improvements in and connected with the sliding block 14 of the
machine tool illustrated in Figures 1 and 2 of the drawings, as herein before
described, and illustrated in Figures 1, 2 3 and 4 of the drawings hereto annexed.
Fourth-The improved frame or tool holder intended to be substituted for the
sliding block 14 of the machine tool shown in Figures 1 and 2 of the drawings con-
structed and arranged as herein before described, and illustrated in Figures 5, 6, 7
and 8 of the drawings hereto annexed.
Fifth The apparatus for holding test pieces while they are being squared in the
machine tool shown in Figures 1 and 2 or in a lathe or other suitable machine tool,
such holding apparatus being constructed and arranged as herein before described,
and illustrated in Figures 9, 10, 11, 12, 13 and 14 of the drawings hereto annexed.
Sixth The hollow cylindrical cutting tool for the purpose of cutting test pieces
from castings, forgings dead-heads and such like, constructed arranged and applied
as hereinbefore described, and illustrated in Figures 15, 16, 17, 18, 19 and 20 of the
drawings hereto annexed.
Dated thin Osh 1000