Improvements in and connected with Disappearing Turrets for Fortifications.
Year: 1892

page_text: Date of Application, 8th Apr., 1892
Complete Specification Left, 9th Jan., 1893-Accepted, 18th Feb.,
1893
PROVISIONAL SPECIFICATION.
Improvements in and connected with Disappearing Turrets for
Fortifications.
I, GEORGE FREDERICK REDFERN, of the firm of G. F. Redfern & Co. The
General Patent Office, No. 4, South Street, Finsbury, in the County of London,
Patent Agents, do hereby declare the nature of this invention (a communication
to me by André Christophe, of 46, Avenue Maillot, Neuilly-sur-Seine, in the
Republic of France, Civil Engineer,) to be as follows:-
This invention relates to disappearing turrets for fortifications.
In disappearing turrets previously known the surface area of the turret and the
diameter of the well into which the turret descends have been such as to allow the
gun, howitzer or mortar to be raised at the angle of elevation in which the weapon
may generally be required to be fired for different ranges, that is, at an angle of
elevation not exceeding, say 45° to the horizontal. In these positions and allowing
the space required for loading and for the recoil, the weapon has required a well of
a diameter generally greater than the total length of the gun, and the roof of the
turret being of corresponding size has consequently offered a large surface to the
enemy's fire.
The object of my invention is to reduce the surface exposed to the enemy's fire
to very much smaller dimensions than has hitherto been possible, whereby the
weights to be elevated and the weight and cost of material generally are reduced,
and to arrange the movements of the gun, howitzer or mortar within the turret.
According to this invention I keep the gun, howitzer or mortar in a vertical or
nearly vertical position or in a position generally more approaching the vertical
than, the angle at which the gun is likely to be fired while the turret and the gun
are in their lower position, protected by the outer defence of iron or steel rings
embedded in concrete; and while the turret is being raised and in some cases
partially after the turret is fully raised I cause the gun to decline automatically or
otherwise into the position which it has to occupy when firing at the different
ranges. The gun is again moved to its original position during, or partially
previous to, the descent of the turret. In some cases and especially when the gun
is long I have found it useful to give to the gun an accelerated movement in
reference to the turret so that the trunnions of the gun move a larger distance than
the turret itself during the same time. In this way the diameter of the well and
the surface of the roof of the turret can be reduced to very much smaller dimensions
than hitherto.
'
My turret comprises a vertical cylinder which carries the gun, its mounting, and
the recoil buffer (when required) as well as the means for laying the gun at
different elevations. and for firing it, the said cylinder and its roof being of the
desired thickness to resist direct and plunging fire. The base of the cylinder is
fixed to the elevating piston for raising and lowering the turret, the said piston
working within a hollow column or tube. At the lower end of the elevating piston
is a bearing for the chains suspending the counter-weights which equilibrate the
moving weights.
The turret has in addition to its raising and lowering gun, also the necessary gear
for turning it 360° for all round fire and in order to prevent any interference with
this all round movement by the possible slight displacement of the cylinder
surrounding the well the column or tube in which the elevating piston moves rests

page_text: upon ball bearings on a pivot or hemispherical bearing so as to allow the position of
the entire system to be corrected in proportion to such displacement.
The gun proper slides during the recoil in a bed or jacket against the resistance
of the recoil buffer or buffers and is replaced into its firing position by a spring or
springs. On one side of the bed or jacket a toothed segment engages in a pinion or
cog wheel which causes the gun to rotate in order to give it the desired elevation.
This cog wheel has on one part of its periphery teeth which engage with the teeth
of the segment and on another part bevel teeth which engage in a horizontal bevel
wheel fixed to the upper end of a second piston which moves up and down in unison
with the turret. In this second piston a groove is cut, in which runs a pin or stop,
which groove is straight for the portion of the movement of the turret when the
gun is not required to be pivotted and at an angle for the part of the movement
when the gun has to be pivotted. The pin or stop can be raised and lowered as
desired by a hand-wheel and as the turret is always raised to the same height the
position given to the pin or stop will determine the angle to which the gun will be
pivotted.
The horizontal movement of the turret required for laying the turret and the gun
laterally is caused by a pinion moved by hand and engaging with teeth on the
hollow column in which the elevating piston moves, and as the elevating piston is
forced to participate in the lateral movement of the hollow column by means of
protruding parts of the former, the rotation of the hollow column will be transferred
to the elevating piston and to the turret and gun.
The turret and the gun are raised by means of a pinion engaging in teeth cut on
one side of the elevating piston, the counterweights causing this movement to be so
easy that the pinion can be moved by a crank or hand-wheel.
Indicators are placed on suitable parts to shew the angles of elevation and of
direction.
In order to secure the turret at its uppermost position during the firing and in
order that this position shall always be the same, I apply a strong stop-catch,
which, when the turret has reached its highest position, engages in the elevating
piston and prevents it from continuing its upward movement as well as from
descending. This catch is acted upon by a spring or can be applied by hand; and
the catch also acts by suitable intermediary rods or other parts upon the firing
mechanism of the gun so that the gun can be discharged automatically the instant
the catch has engaged, but not before.
This catch must be withdrawn before the turret can be made to descend and
thus acts as a safety-catch against the turret being lowered before the shot has been
fired.
As during the time that the weapon is within the turret it is in a more or less
vertical position it is necessary to provide means for loading and unloading the same,
and I will indicate how this can be done in the case of breech-mechanism having
an interrupted screw. It is to be understood, however, that other forms of breech-
mechanism can be used.
I provide in axial alignment with the gun a loading piston, moved up and down
by a pinion acting in teeth cut on the piston.
When loading, the breech of the gun rests on the upper end of the loading piston
and the cartridge is placed on the top of the breech, I then raise the loading piston
until the cartridge and the breech are inserted into the gun; I then turn the
loading piston by means of a closing handle engaging in a groove in the piston until
the breech is closed by the interrupted screw being turned to the full extent of its
movement; the loading piston is then lowered.
When unloading I proceed in the contrary way, the empty fired cartridge case
being withdrawn, together with the breech, by the downward movement of the
loading piston.
In order to prevent the possibility of the turret and gun being raised before the
breech is properly closed, I cause a part of the closing handle to engage in the main
elevating piston in such a manner that the latter cannot be raised until the loading

page_text: handle has fully closed the breech at which moment it disengages from the elevating
piston and leaves the turret free to ascend.
Dated this 8th day of April 1892.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION..
Improvements in and connected with Disappearing Turrets for
Fortifications.
I, GEORGE FREDERICK REDFERN, of the firm of G. F. Redfern & Co., The
General Patent Office, No. 4, South Street, Finsbury, in the County of London,
Patent Agents, do hereby declare the nature of this invention (a communication
to me by André Christophe, of 46, Avenue Maillot, Neuilly-sur-Seine, in the
Republic of France, Civil Engineer) and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to disappearing turrets for fortifications.
In disappearing turrets previously known the surface area of the turret and the
diameter of the well into which the turret descends have been such as to allow the
gun, howitzer or mortar to be raised at the angle of elevation in which the weapon
may generally be required to be fired for different ranges, that is, at an angle of
elevation not exceeding, say 45° to the horizontal. In these positions and allowing
a well of
the space required for loading and for the recoil, the weapon has required
a diameter generally greater than the total length of the gun, and the roof of the
turret being of corresponding size has consequently offered a large surface to the
enemy's fire.
The object of my invention is to reduce the surface exposed to the enemy's fire
to very much smaller dimensions than has hitherto been possible, whereby the
weights to be elevated and the weight and cost of material generally are reduced,
and to arrange the movements of the gun, howitzer or mortar within the turret.
According to this invention I keep the gun, howitzer or mortar in a vertical
or nearly vertical position or in a position generally more approaching the vertical
than the angle at which the gun is likely to be fired while the turret and the gun
are in their lower position, protected by the outer defence of iron or steel rings
embedded in concrete; and while the turret is being raised and in some cases
partially after the turret is fully raised I cause the gun to decline automatically or
otherwise into the position which it has to occupy when firing at the different
ranges. The gun is again moved to its original position during the descent of the
turret.
To enable my invention to be fully understood I will describe the same by
reference to the accompanying drawings, in which :-
Figure 1 is a central vertical section through the well and chamber of the turret,
the mechanism for operating the gun being shewn in elevation; and,
Figure 2 is a similar view to Figure 1 but looking in the direction of the
arrow 1:
Figure 3 is a section on the line 3-3, Figure 2:
Figure 4 is a view similar to the upper part of Figure 3 but shewing the turret
raised and the gun in the firing position :
Figure 5 is a section on the line 5-5, Figure 1.
Similar letters of reference indicate corresponding parts in the several figures.
a is the armour round the well containing the turret, which armour is supported
upon the upper ends of stanchions a¹, a', which latter by means of intermedia.e
plates carry the weight of the concrete and earth-work by which the turret is
surrounded. b is a cylinder adapted to be moved vertically within the well an
the
forming the turret proper, the said cylinder serving to carry
and its
gun

page_text: mountings and having an opening 6x at one side through which the gun can he
projected as hereinafter described. The said cylinder is provided with a roof.or
cover at its upper part, which roof or cover when the cylinder is in its lower-
most position is practically flush with the surface of the earth-work surrounding
the turret.
is a gauge-ring which is arranged at the upper part of the well and into which
the upper and lower parts of the cylinder b which are slightly larger in diameter
than the other parts of the cylinder are adapted to fit so that when the turret is in
either its upper or lower position it will be held central relatively to the well.
By making the intermediate portion of the cylinder of slightly less diameter
than the ends I ensure the movement of the said cylinder with only slight friction.
c is a rod or piston carrying at its upper end the turret b which is provided with
a cross-bar or bridge-piece c' in a hole or recess in which the upper end of the said
rod c fits whilst the lower end of the said rod is carried in a step-bearing ³ to which
a rope or chain or ropes or chains carrying a weight c for balancing the gun and
its accessories is connected so that the up-and-down movements of the turret can be
effected with as little labour as possible, the said ropes or chains passing over
suitable pulleys, c on the underside of a base plate c. The vertical movement
of the said rod c for raising and lowering the turret and gun is effected by means
of a hand-wheel d secured to a shaft d carrying a pinion & engaging with rack-
teeth upon the said rod c, the said shaft d¹ having bearings in a hollow column or
sleeve e surrounding the rod c, the said sleeve being adapted to rotate with the
shaft c as hereinafter described and being supported at its lower end upon a ball-
bearing upon a guide y through which the rod c slides, the well with the turret
sliding therein serving to guide the upper end of the said rod.
As the repeated explosions of an enemy's projectiles in the neighbourhood of
the turret might cause the displacement of the armoured well a and thereby if the
guide was a fixture cause the turret to jam owing to the eccentricity of the well
relatively to the said turret and thus render the gun within the same practically
useless, I mount the said guide g upon a hemispherical block g¹ preferably of wood
and carried in a corresponding seat in the base-plate e so that in case the well is
displaced the turret will be free to follow the movements thereof without causing
the jamming of the rod c in the said guide.
is the gun, which, as shewn in the drawing, is adapted to slide in a bed or
cradle formed integral with the buffer cylinder 2, the said cradle and buffer
cylinder being suitably mounted upon trunnions ³, h³ in the turret b in such a
manner that the cradle with the gun therein can be turned upon the trunnions to
project the gun through the opening in the turret. The rear part of the gun
has upon it a ring i, a projection upon which is connected to the rod i of the
buffer piston, as shewn most clearly in Figure 4.
As hereinbefore stated the gun when within the turret occupies a vertical position
or a position more or less approaching the vertical.
In order that during the time the turret is being raised the gun shall be caused
to project through the opening in the turret at a proper angle for the discharge,
I provide the following arrangement, that is to say, upon one side of the bed or
cradle and concentric with the trunnions I fix a toothed segment j with which gear
the teeth upon the periphery of a disc. I also form upon the said disc a series of
bevel-teeth with which engage the bevel-teeth of a segment. This segment j
is secured to the upper end of a second piston or shaft & extending through and
having a bearing in the cross-bar c' of the turret, the said segment serving also
as a collar for causing the said shaft k to participate in the vertical motions of the
said turret. The lower part of the said shaft & slides in guides in two arms k¹, k¹
carried by the hollow column or sleeve e.
As in practice it is not necessary to move the gun through an angle. of more
than, say, 90°, that is to say, from a vertical to a horizontal position I have arranged
the teeth of the segment j, of the disc and of the segment j so that a quarter of
a revolution of the said segment will impart the necessary movement to the gun.

page_text: l
The rotation of the shaft k for effecting the rotation of the segment through a
quarter of a revolution during the elevation of the gun is as follows,-that is to
say,
the shaft k is provided throughout its length with a groove l, one part of which
is straight whilst the other part is spiral, as shewn most clearly in Figure 2. Into
this groove projects a lug l upon a nut held against rotation but capable of
being moved vertically by means of a screw m carried in suitable brackets upon
the guide-arms k¹, k¹ and adapted to be rotated by a hand-wheel m'. With this
arrangement it is obvious that whilst during the raising of the turret with the gun
and the shaft k by the upward movement of the rod c the lug is in the straight
part of the groove / no movement in a rotary direction will be imparted to the said
shaft k: when, however, during the continued upward movement the spiral part of
the groove acts upon the lug it is obvious that the said lug upon the nut being
stationary, the shaft k will be caused to rotate. By varying the vertical position
of the said nut P, it follows that during the upward movement of the turret a
greater or less amount of rotary movement will be imparted to the said shaft k
according to how much of the length of the spiral part of the groove / comes into
engagement with the lug. For instance, if the nut is in the position shewn in
Figure 3, that is to say, at the upper end of the screw m it follows that only a
small portion of the spiral part of the groove I will act against the said lug so that
the gun will only be moved a relatively short distance out of a vertical position
whilst, when the nut is at the bottom of the screw m, the whole of the spiral part
of the groove will engage the said lug so that the shaft k will be moved a quarter
of a revolution and move the gun to a horizontal position.
It will be obvious that by varying the position of the nut the elevation at
which the gun is fired can be accurately determined, and to facilitate the adjust-
ment of the said nut I arrange in conjunction with the brackets carrying the
screw m a graduated scale n, as shewn in Figure 2, a pointer attached to the nut
sliding over the said scale.
I effect the rotary movement of the turret for enabling the gun to be fired in
any direction by the following means, that is to say,-On the upper end of a tubular
column o formed integral with the rod guide I form or fix a worm-wheel o¹,
Figures 2 and 3, and in a bracket o' upon the sleeve e I mount a shaft o³ carrying
a worm of at one end engaging with the wheel o' aud provided at the other end
with a hand-wheel of by means of which the said worm may be rotated. With this
arrangement it will be obvious that by rotating the said wheel o in one or the
other direction the sleeve e will be caused to rotate relatively to the column o, the
friction between the hemispherical bearing surface carrying the guide to which
the column o is attached being sufficient to prevent the said column from moving.
The anti-friction balls at the lower end of the sleeve also serve to facilitate the
movement of the latter relatively with the column o. It is to be understood that
the sleeve e is connected with the rod e by means of a spline or feather so that any
rotary motion imparted to the said sleeve is also communicated to the said rod c
whilst at the same time the rod c is free to move in a vertical direction without
affecting the said sleeve.
In order that the direction of fire may be accurately determined, I arrange
adjacent to the column o a graduated ring p.
Although I may employ in my turret, guns provided with different systems of
breech, I nevertheless prefer one closed by means of a screw-block having inter-
rupted threads and to employ an arrangement of mechanism for the introduction of
the charges into the gun.
This arrangement of mechanism consists of a rod y having circular rack-teeth
and the upper end of which is square and adapted to engage in a corresponding
recess made in the back part of the breech-block 9', as shewn in Figure 3, the said
rod sliding through a guide g³ carrying a pinion 9 engaging with the teeth of the
rack and operated by a crank-handle q. The said rod q is provided throughout
its length with a straight groove in which a pin upon a collar surrounding the
said rod engages, the said collar having a lever I to enable it to be turned, as

page_text: shewn in Figure 5. It will be obvious that, in opening the breech, if the rod q is
raised by actuating the crank-handle in the required direction, the square end of
the said rod will first enter the corresponding recess in the breech-block and that
then by moving the lever r¹ a rotary movement can be imparted to the breech-
block to disengage it from the screw-thread in the gun. On turning the crank-
handle g in the opposite direction the rod 7 will be lowered with the breech-block.
If a projectile and its charge enclosed in a metal cartridge case be now placed upon
the breech-block, as shewn in Figures 1 and 3, and the movement herein before
described of the crank-handle q be repeated, the charging of the gun will be
effected and the breech will be locked by actuating the lever ¹ of the collar in
an opposite direction to that in which it was previously operated.
To prevent the turret from being raised before the charging and the closing of
the breech shall have been accomplished I provide the collar with a sector r³,
Figure 5, adapted to engage in a notch made in the central rod c, thereby pre-
venting any vertical movement of the latter until the lever r¹ has been actuated in
order to disengage the sector from the rod c, which operation at the same time
locks the breech-block in the gun.
To effect the firing of the charge, the breech-block of the gun is provided with
the usual firing mechanism (striker, detent and spring) but in order that the firing
shall only take place at the precise moment when the angle of ure previously
determined shall have been attained, that is to say, at the moment when the eleva-
tion of the turret has been completed I have arranged an automatic firing apparatus
which can only work under the condition above named.
At the level of the breech-block and on one side of the gun projects a detent-
pushers, and an arm s', mounted on a rod t and of a shape which allows it to be
adjacent to the detent-pushers in all the different positions the said pushers may
occupy during the movement of the gun around its trunnions, is adapted to be
moved by a lever . This rod t participates in the rotary movement of the turret,
being supported near its upper end in a bearing 2 on the cross-bar c' of the turret
and sliding at its lower part through a guide t upon the upper part of the sleeve e.
The rod is moved by the lever to cause the arm s¹ to impinge against the detent-
pushers to fire the gun. The said lever t' has formed integral with it an arm v,
Figure 5, pressed against the central rod c by a spring v¹ fixed on the sleeve e and
adapted with its free end to enter a notch v³ in the rode when the latter is in its
uppermost position. The result is that as soon as the said notch 2 of the rod c
comes opposite the arm the latter will under the action of its spring enter the said
notch and thus cause the rotary movement of the rod t which will thereby actuate
the arms to press the detent-pusher s. In this manner not only will the auto-
matic discharge of the gun be effected but also the vertically ascending movement
of the rod c will be limited.
To cause the turret to disappear after the discharge it is only necessary for the
attendant to move the lever t¹ to disengage the arm from the notch and then
turn the wheel d in the required direction.
Instead of firing the gun by mechanical means I may employ electricity.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. An armoured turret adapted to be raised and lowered in an armoured well,
the diameter of which is considerably less than the length of the gun within the
turret, substantially as described.
2. The combination with an armoured turret adapted to be raised and lowered
in a well by means of a vertically moving piston or rod the lower part of which
slides in a guide, of a hemispherical block carrying the said guide and adapted in
case of any axial displacement of the turret and piston or rod to follow the same,
substantially as, and for the purpose, described.

page_text: 3. The combination with an armoured turret of a diameter less than the length
of the gun which it contains, of means whereby, during the raising of the turret,
the gun will be moved from the position which it occupies during the time that the
turret is in its lowermost position to the required angle for firing, and during the
lowering of the turret be again moved into a vertical or nearly vertical position,
substantially as described.
4. The combination with an armoured turret of a diameter less than the length
of the gun which it contains, of means substantially as herein before described for
causing the gun to pivot upon its trunnions during the ascent of the turret to such
an extent that, when the turret is fully raised, the gun is at the required angle for
firing, substantially as described.
5. The combination with an armoured turret of the kind hereinbefore described,
of means for charging the gun whilst in a vertical or approximately vertical position,
substantially as described.
6. The combination with an armoured turret of the kind hereinbefore described,
of meaus for ensuring that the raising of the turret shall not be commenced before
the breech of the gun is closed, substantially as described.
7. The combination with a turret of the kind hereinbefore described of means for
firing the gun and of ensuring that the firing shall not take place before the turret
is completely raised, substantially as described.
8. The improved disappearing armoured turret consisting of the parts constructed
and combined substantially as bereinbefore described and illustrated in the accom-
panying drawings and operating as, and for the purposes, set forth.
Dated this 9th day of January 1893.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.