Improvements relating to the Manufacture of Hollow Projectiles or Shells and to Apparatus therefor.
Year: 1890

page_text: Date of Application, 18th July, 1890
Complete Specification Left, 5th Dec., 1890-Accepted, 10th Jan., 1891
PROVISIONAL SPECIFICATION.
Improvements relating to the Manufacture of Hollow Projectiles or
Shells and to Apparatus therefor.
I, ROBERT Low, of Eildon House, Macaulay Road, Clapham in the County of
Surrey, Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to the manufacture of hollow projectiles or shells for guns of
large or small calibre and to improved apparatus to be used in such manufacture.
My said invention comprises an improved method of manufacturing a hollow
projectile or shell in one heat from a cup-shaped blank of iron or steel.
An important feature of my said improved process is the forging of the said blank
by forcing the same through or between a series or group of revolving squeezing rolls
in the direction of the length of the said rolls. Or I may provide for forging the
blank by passing it gradually between suitable companion half-lies mounted the one
part in the head and the other in the anvil of a steam hammer, the head of which is
kept meanwhile in a constant state of rapid vibration.
My said invention, moreover, comprises improved construction of apparatus for
forging the heated blank and forcing the said blank through the said squeezing rolls
or dies and for other purposes connected with the manufacture of armour piercing
common or shrapnel shells or hollow projectiles according to my said improvements.
In making a hollow projectile or shell according to my said invention I find it advan-
tageous to proceed as follows:-That is to say, I take a solid block or ingot and first
form by punching or cupping or otherwise, a central hole or cavity in the ingot thus
forming a blank. I then heat the said blank and place the same on the end of a
mandrel having a diameter suited to fit into the aforesaid central hole or cavity. The
said mandrel may be mounted to form a continuation of the plunger of a hydraulic
ram preferably in such a manner that while compelled to move in and out with the
said plunger it is quite free to rotate, ball bearings being provided if desired to reduce
the friction between the mandrel and plunger. Or in lieu of employing a hydraulic
the
ram I may provide the said mandrel with a strong screw-thread and
through a corresponding nut fixed in a suitable stationary standard, so that by rotating
the mandrel I provide for advancing and retreating the same. I moreover provide
preferably three chilled cast iron or other suitable rolls removably fixed on axles
mounted to rotate in any suitable bearings, the axes of the said rolls being parallel to
each other and situated at the angles of a triangle the centre of which is in line with
the aforesaid mandrel for carrying the heated blank to be forged. One or more of the
roll axles is or are preferably mounted in sliding bearings and can be adjusted by
screws or otherwise for slightly varying the size of the central space between the rolls
in a well known manner. provide for driving the rolls by a strong annular preferably
steel wheel toothed internally and externally mounted on a central shaft and gearing
internally with wheels on the roll axles and externally with a driving wheel; or I may
drive the rolls in any other convenient manner.
pass
same
Having mounted the heated blank on the mandrel provided to receive it I slowly
force the said blank in a longitudinal direction through the space between the rotating
rolls by means of the hydraulic ram or screw device and in this manner I reduce the
blank to the desired shape and size for forming the shell.
In some instances I find it advantageous to provide apparatus for preventing the blank
being advanced through the rolls too rapidly. For this purpose I may employ a second
small bydraulic ram placed between the roll axles and arranged to have its plunger
abutting against the forward end of the blank. The said ram communicates with an
accumulator or head of water to supply the necessary resisting force. In some cases
I employ a spring supported spindle instead of a hydraulic ram for this purpose.

page_text: To facilitate the removal of the finished rolled shell from its mandrel I may provide
a stationary sleeve or bracket embracing the said mandrel in a position behind the
shell. The said sleeve is of less internal diameter than the external diameter of the
shell, so that when the mandrel is withdrawn from the rolls the rear portion of
the shell will encounter the fixed sleeve or bracket and be therewith stripped from the
mandrel.
I prefer to provide a series of rolls of different diameters which may be substituted
for each other so that shells of different sizes may be forged in the same machine.
To prevent injury to the driving gear in case the rolls from any cause should become
wedged fast or otherwise unduly stressed when rolling, I arrange that in each roll
axle there shall be a weak coupling or other device that under the said circumstances
will give way. The said couplings or weak places are amply strong to drive the rolls
under normal conditions but are so weak as to ensure giving way under any abnormal
stress before there is a possibility of injury to the driving gear.
In the molification of my invention wherein I employ a steam hammer instead of
rolls for forging the blank 1 prefer to use the aforementioned screw arrangement
for advancing the said blank and the spring buffer herein before described for
preventing the blank leaving the mandrel. Moreover I mount the supporting
brackets of the said screw and spring arrangements, on springs within vertical
sockets or similar dovices which allow of an elastic up and down movement while
preventing lateral motion so that as the blank becomes smaller in diameter it may
still rest on the anvil-block or die. Pins may be passed through slots in the up
and down sliding brackets and through the sockets to limit the extent of the
movements of the brackets. Suitable half-dies are mounted in the hammer head.
and in the anvil, and the hammer head is kept in a contact state of rapid vibration
while the blank is being passed through. For advancing the blank automatically
I may provide a ratchet wheel on the outer end of the screw mandrel and a pawl
engaging therewith and actuated through a chain or other connection by a vibrating
lever operated by the hammer head.
Doted this 10th of Jul 1900
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
'
COMPLETE SPECIFICATION.
Improvements relating to the Manufacture of Hollow Projectiles or
Shells and to Apparatus therefor.
I, ROBERT LOW, of Eildon House, Macaulay Road, Clapham, in the County of Surrey,
Engineer, 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 hollow projectiles or shells for guns of
large or small calibre and to improved apparatus to be used in such manufacture..
My said invention comprises an improved method or process of manufacturing
a hollow projectile or shell, in which process the forging of a cup-shaped blank
to elongate the same and reduce its external diameter and the thickness of its wall,
is effected by forcing the said blank end wise through or by subjecting the same to
compression between a series or group of revolving squeezing rolls in the direction
of the length of the said rolls, that is to say in a direction parallel to the axes of the
said rolls, or by passing or feeding the said blank gradually between suitable
companion half-dies or swages mounted one in the head and the other in the anvil or
anvil-block of a steam-hammer or a hydraulic press reciprocating motion being
meanwhile imparted to the said head. The open end of the forging thus produced is
closed or partially closed as may be required in any well known or other suitable
imanner.
By my improved method I am enabled to forge a hollow projectile or shell from a

page_text: cup-shaped blank with a less number of heats than is practicable with the methods
heretofore adopted.
My said invention, moreover, comprises improved apparatus for the manufacture of
armour-piercing, common or shrapnel shells according to my said improved method
or process.
In the accompanying drawings I have shown apparatus constructed in accordance
with my said invention whereby the forging of shells may be conveniently and
advantageously carried into practice.
Figure 1 is a side elevation of one form of my improved forging-machine.
Figure 2 is a plan of the same, partly in horizontal section.
Figure 3 is a plan partly in horizontal section, showing a modification of the
apparatus shown in Figures 1 and 2.
Figure 4 is a transverse section on the line
of construction.
x, Figure 1, showing certain details
Figure 5 is a transverse section on the line y y, Figure 1, showing a movable
standard hereinafter referred to.
Figure 6 is a transverse section on the line z z, Figure 2.
Figure 7 is a transverse section on the line z¹ z¹, Figure 2.
Figures 4 to 7 inclusivo are drawn to an enlarged scale.
Figure 8 is a vertical longitudinal central section of part of my machine for forging
projectiles between a pair of dies or swages mounted upon the anvil-block and the
hammer-head of a steam hammer.
Figure 9 is an end view of the said dies or swages, drawn to an enlarged scale.
Figure 10 is an end elevation, drawn to the same scale as Figure 8, of the said
machine showing combined therewith a device heroinafter described for automatically
rotating the work between the dies.
Figure 11 is a side elevation, drawn to an enlarged scale, of a detail of the apparatus
shown in Figure 10.
Figures 12 to 20 are central sections illustrating different steps or stages in the
manufacture of projectiles in accordance with my said invention.
Like letters of reference indicate corresponding parts throughout the drawings.
In the apparatus shown in Figures 1 to 7, A, A are the rolls which are secured
upon shafts B carried in suitable bearings B1 B2 in the housings or standards C, C
D is a hydraulic cylinder which is supported in a suitable standard D', and the ram E
of which provided with a mandrel F connected thereto by a coupling G. This
mandrel serves to support the blank H during the operation of rolling the same, and
to preserve or determine the shape of the chamber or cavity therein. I is another
hydraulic cylinder, the ram J of which is acted on by a head or pressure of water
from an accumulator or pressure-main. The cylinder I is situated, as shown, in such
a position that its ram J is in line with the mandrel F, and can press against the
blank H for the purpose of holding the same on the mandrel and preventing distortion
of the said blank, whilst permitting longitudinal movement thereof between the rolls A.
Or, in place of this device, I can use a plunger acted upon by a suitable spring tending
to press it with sufficient force against the blank H for the purpose above specified.
The rolls A are preferably made of chilled cast iron. These rolls are secured upon
the shafts or axles B in such a manner, that they can be easily removed therefrom
when desired, to allow of rolls of different form or diameter being substituted therefor,
and the said shafts are by preference so arranged that the axes thereof are parallel to
each other, and equidistant from the axis of the said mandrel F, as shown more clearly
in Figures 4 and 5. The said rolls are, moreover, formed, as shown, with their
forward ends, which first operate upon the blank, tapered or conical so that they will
gradually reduce the diauieter of the blank and more readily work the metal back
over the mandrel.
-
I prefer to mount one or more of the rolls in adjustable bearings, as shown for
example at B (Figures 4 and 5), which bearings can be moved towards or away from
the axis of the mandrel for the purpose of slightly varying the size of the central.
space between the rolls. This adjustment is effected by means of a screw B³, which,

page_text: for the purpose of turning it has secured upon its outer extremity a toothed wheel B*,
and a handle B'. This handle is coupled to the screw by a suitable joint so that it is
free to turn about the axis of the screw and to be raised and lowered to disengage it
from or cause its engagement with one or other of the teeth of the wheel B. By
means of the said handle the wheel B* can be turned through any desired angle to
operate the screw B³.
Other convenient means may however be provided for operating the said screw.
I find it advantageous to provide for driving the rolls A by means of toothed gearing
comprising a strong annular toothed wheel O which is provided with teeth both
internally and externally, and is mounted on a shaft O. The wheel O is geared
internally with toothed wheels or pinions P fixed on the roll axles B; and the said
wheel O is geared externally with a driving pinion Q fixed upon a shaft Q¹ to which
motion is imparted by a belt Q3, from the shaft of an engine or other suitable motor
or otherwise. Or I provide other convenient means for driving the said rolls.
In making a hollow projectile or shell according to my said invention, I proceed
as follows: That is to say, I take a circular piece or disc of metal such as that shown
in Figure 12, and, by means of suitable dies, I work the same into a cupped form in
a manner similar to the first operation performed in the manufacture of a metallic
cartridge-case as heretofore practised. I thus produce a blank H, as shown in
Figure 13. Or I take a solid block or ingot of metal, such as shown in Figure 14,
and form a central hole or cavity therein, by punching or otherwise while the ingot
is supported in a mould adapted to impart to its exterior a slightly taper or conical
form as shown in Figures 15 and 17. The central hole or cavity may be slightly
tapered towards its inner end as shown in Figure 15, or it may be of any other con-
venient form; for instance, in a shrapnel-shell, it may have the form shown in
Figure 17, the main cavity being of considerable diameter, and having a cup-
shaped recess of smaller diameter at the bottom thereof adapted to serve as the
chamber for the bursting-charge.
In the case of armour-piercing shells, I form a pointed or conoidal cup-shaped
blank by either of the methods above described. Or I take a metal bar, and, by
swaging under a steam hammer, I forge therefrom simultaneously two pointed or
conoidal blanks, and in these blanks I form a central hole or cavity by punching or
otherwise, thus producing a cupped blank of the shape shown in Figure 19.
I take either of the aforesaid cup-shaped blanks Hand after heating it place it on
the end of the mandrel F which is of such size and form as to exactly fit the central
hole or cavity in the blank. The said mandrel, as above mentioned, forms a con-
tinuation of the ram E. It is coupled to the said ram in such a manner that, while
compelled to move to and fro with the said ram, it is free to rotate relatively thereto,
suitable ball-bearings E (Figure 2) or other convenient means being provided, if
desired, to reduce the friction between the mandrel and the ram.
Having mounted the heated blank H on the mandrel F, I start the rolls and slowly
force the said blank end wise or in a longitudinal direction through the space between
the said rolls by means of the ram E. By the combined action of the rolls A and the
mandrel F, I reduce the blank by forcing the metal thereof along the mandrel till it
acquires the desired shape and size, as shown for example in either of the Figures 16,
18 or 20.
To prevent the too rapid movement of the blank H through the space between the
rolls, and to retain the said blank on the mandrel, and preserve the shape of the
central chamber or cavity and of the base of the shell I employ the buffer-cylinder I,
which is placed between the roll-axles, and the ram of which abuts against the closed
end of the blank. The said cylinder is in communication with an accumulator or
pressure-main (not shown in the drawings) from which the necessary resisting force is
supplied; or, in case water-pressure is inconvenient or unobtainable, the required
resisting force may be obtained as above specified by means of a spring K as in the
modification of my apparatus shown in Figure 8.
To facilitate the removal of the rolled shell from the mandrel F, I provide in a
suitable position a sleeve or clip which may he placed around the said mandrel, and

page_text: the internal diameter of which is less than the external diameter of the shell, so that,
when the mandrel is withdrawn from the rolls, the shell will encounter the said sleeve
or clip and be thereby stripped from the mandrel.
This clip or sleeve is sometimes constructed as shown in Figure 6, in which R R¹
represent respectively the upper and lower jaws of the clip, which is supported by
suitable arms or studs S S₁ secured in the standard D', the said jaws R R¹ being
pivoted upon the stud S and adapted to engage with the stud Š¹. Both of the
jaws R R are provided with suitable counterweights R'. A catch serves to hold or
lock the said jaws together when the clip is closed, this catch being pivoted to the
jaw R and having a projection or collar adapted to engage with the jaw R'. The
said counterweights R' are of such weight relatively to the jaws R R* that the said
jaws will, on the disengagement of the catch r, separate from one another the upper
one rising and the lower one falling, until they occupy the positions indicated by
dotted lines in Figure 6, and can be closed with the exertion of very little strength.
The jaws R R are so shaped as to closely surround the mandrol, so that when the
same is drawn back with the projectile thereon, the projectile will engage with the
said jaws and, in the continued backward movement of the mandrel, the shell will be
stripped or removed therefrom.
Or I provide for this purpose a clip formed of two sliding pieces arranged in
proximity to the housing, or standard C¹ so that when the two parts of the clip are
brought together they will prevent the withdrawal of the shell with the mandrel F
from between the rolls. After the withdrawal of the said mandrel the shell is ejected
from between the rolls by means of the ram J.
In lieu of the hydraulic cylinder D and ram E I sometimes provide the mandrel F
with a strong screw-thread F1 as shown in Figure 8 which passes through a corr³-
sponding internally screw-threaded block or nut L fixed in a suitable stationary
standard M so that, by rotating the mandrel in one or the other direction I can
advance or withdraw the same, and if necessary simultaneously rotate the blank.
In some instances I combine with the ram E, two or more cylinders D2 having
their piston rods 1)³ connected to a cross-head E' secured upon the ram E' as shown
in Figure 3, these auxiliary cylinders serving to return the said ram after it has
performed its work.
I prefer to provide a series of interchangeable rolls of different diameter one set of
which may be substituted for another, so that shells of different sizes may be forged
in the same machine. To facilitate the changing of these rolls, I so construct the
housing or support C' of the bearings of the axles B, that it can slide longitudinally
to and fro from the rolls in guides C secured to the base-plate or foundation of the
machine, as shown in Figures 1 and 5. A screw shaft C is supported in bearings in
the base plate and is arranged to be turned by a suitable key or otherwise for the
purpose of moving the housing or standard Cf which is provided with an internally
screw-threaded projection or nut C in which the said screw-shaft works. It will be
readily seen that, by moving the said standard (away from the axles B, the rolls
can be easily slipped off the ends of the said axles and other rolls fitted thereon..
Suitable holding-down bolts Care provided for securing the standard C₁ firmly upon.
its base plate. To prevent injury to the driving gear in case the rolls from any cause
should become wedged fast or otherwise unduly strained when working, I provide
each roll axle with a comparatively weak coupling U or equivalent device that will
yield under any undue stress. The said coupling or weak places are strong enough
to drive the rolls under normal conditions, but their strength is sufficiently small to
ensure their giving way under any abnormal stress before there is a possibility of
injury to the driving-gear.
In the modification of my invention shown in Figures 8 to 11, I employ a steam
hammer or a hydraulic or other forging press instead of rotating rolls for forging the
blank, the head V of the said steam-hammer or hydraulic press and the anvil block V¹
being provided respectively with dies or swages W W. These dies or swages have
formed therein suitable recesses W' so that, when the hammer-head is lowered and
the two dies are in contact, or nearly in contact with each other the recesses enclose a

page_text: space or cavity of approximately the same diameter as the finished shell and having
a flaring or divergent opening at that side on which the blank enters the space
between the dies.
In this modification of my invention, I prefer to use the above mentioned screw
arrangement for advancing the mandrel and blank, I mount the supporting bracket or
nut for the screw F1 and I also mount the cylinder I upon plungers F2 adapted to
slide up and down within vertical sockets M and supported in the said sockets upon
suitable springs K' or I use similar devices which form an elastic cushion and permit
up and down movement while preventing lateral notion of the plungers, so that as
the blank H is reduced in diameter it may still rest upon the lower die W.
In forging a shell in this modified form of my apparatus the blank H is placed
upon the screw-threaded mandrel F, and the said mandrel is then turned slowly by
hand or otherwise, and thus fed or moved forward by the working of its screw-threads
in the nut L. The hammer-head is during this feeding motion, kept continually at
work, thereby shaping the blank as desired. When this is done, the steam hammer is
stopped and the hammer-head lifted, and the mandrel is turned in the other direction,
thereby screwing it back in the nut L; the end of the projectile comes into engage-
ment with this nut and is thus separated from the mandrel in the continued backward
movement thereof. Suitable pins or stop pieces M¹ are preferably passed through
slots F3 in the vertical sliding supports or plungers F' and through the sockets M to
limit the extent of the movement of the said supports or plungers.
Although I may rotate the mandrel F by hand I prefer to provide for the automatic
rotation thereof by means of a ratchet wheel a and pawl & shown more clearly in
Figure 10. The said ratchet-wheel is fixed on the outer end of the mandrel F. The
pawl 6 is carried by an arm c pivoted upon the mandrel and connected with a rocking
lever e by means of a chain d, the said rocking lever being actuated by the rising and
falling of the head V. A suitable engagement piece or projection f, shown more
clearly in Figure 11, is secured to a bracket g upon the head V and projects into the
path of the rocking-lever e so that, in the upward movement of the head, it engages
with the said lever and raises the same, thereby raising the arm c and causing the
pawl b to engage with a fresh tooth of the wheel a and rotate the mandrel, the chain
connection d permitting the simultaneous end wise movement of the mandrel. In the
downward movement of the head, the arm e descends by gravity thus moving the
pawl relatively to the ratchet wheel preparatory to the next feed movement.
I close or partially close the open end of the forged shell in any convenient manner,
for instance by means of rotary dies as described in the 'Specification accompanying
my application for Letters Patent dated the 11th of April A.D. 1890, No. 5530 or by
means of swages subjected to pressure or impact, the shell being gradually fed between
the said swages.
In some instances I may so arrange the rolls that by means of adjustable bearings
or otherwise one or more of them can be moved out of position to permit the blank to
be placed between the rolls, and can then be caused to act thereon for the purpose of
compressing and spreading or forcing the metal thereof along the mandrel till the
desired shape is imparted thereto.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I wish it understood that I do
not claim broadly or irrespectively of my improvements herein described the forging
of a hollow cylinder by means of rotating squeezing rolls between which the blank is
caused to move endwise; nor do I claim generally or irrespectively of my said
improvements the manufacture of a hollow projectile or shell from a circular piece or
disc. of metal or from a cup-shaped blank, but I claim :-
First. The manufacture of a hollow body for a projectile or shell by forging a blank
on a mandrel in a space enclosed or bounded by rotating surfaces operating as and for
the purposes specified.
Second. In the manufacture of a hollow projectile or shell the improved method of
elongating the oup-shaped blank and reducing its diameter and the thickness of its

page_text: wall, upon a suitable mandrel whereby it is forced between rotating squeezing rolls in
a direction parallel to their axes or between suitable dies or swages subjected to
pressure or impact, and is continuously or intermittently rotated about its axis, for
the purposes, above specified.
Third. The combination with the rotary squeezing-rolls or with the dies or swages
in the head and anvil-block, of the hydraulic feeding cylinder and the mandrel
coupled to the ram of the said cylinder in such a manner that, whilst free to rotate
relatively to the said ram, the mandrel will participate in the to-and-fro movement
thereof. substantially as, and for the purposes set forth.
Fourth. The combination, with the rotary squeezing rolls (or with the head and
anvil-block provided with the dies or swages) the mandrel and the feed apparatus of
means such as I have herein before described for retaining the blank on the said
mandrel and controlling the movement of the same through the space between the
rolls dies or swages as above specified.
Fifth. In a machine for forging hollow projectiles or shells, between a fixed and a
moving die or swage, a mandrel for supporting the blank, and hydraulic or other
suitable apparatus for imparting intermittent rotary motion to the said mandrel and
for feeding the same with the blank thereon, endwise or longitudinally between the
said dies or swages, substantially as, and for the purposes, above specified.
Sixth. The combination, with the rotary squeezing rolls (or with the head and
anvil-block provided with the dies or swages,) of the screw-threaded mandrel working
in the nut and provided with means for turning it about its axis to intermittently
rotate the blank and feed the same endwise between the rolls, dies or swages,
substantially as hereinbefore described.
Seventh. The combination with the dies or swages of the elastic supports or cushions
for the buffer cylinder I and screw-nut L substantially as, and for the purposes, above
specified.
Eighth. The improved forging-machine constructed substantially as described with
reference to Figures 1 to 7 or with reference to Figures 8 to 11 of the accompanying
drawings and operating as above specified.
Ninth. A hollow projectile or shell manufactured by or according to the method
herein described.
Dated this in day of December 1oU.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.