Improvements in Apparatus for Controlling the Recoil and Running Out of Guns.
Year: 1889

page_text: Date of Application, 9th Nov., 1889
Complete Specification Left, 8th Aug., 1890-Accepted, 8th Nov., 1890
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Controlling the Recoil and Running
Out of Guns.
I, PER NORDENFELT of 32 Victoria Street in the City of Westminster Engineer do
hereby declare the nature of this invention to be as follows:-
In recoil apparatus in which some of the force of the recoil is stored up by the
compression of a spring or otherwise and is at the end of the recoil allowed to at
once run out the gun we employ control mechanism for controlling the running
out which is independent of the control mechanism by which the recoil is controlled
so that either one can be modified or adjusted without affecting the other.
Usually the recoil is controlled by a hydraulic cylinder the fluid in which has to
pass through a small passage or passages from one side of the piston to the other
during the recoil--and power is at the same time stored by the compression of a
spring.
To control the running forward of the gun by the spring at the end of the recoil
we use a second independent cylinder preferably we mount this additional cylinder
at one end of the recoil cylinder and the pistons of both cylinders we carry on the
same rod.
The piston of the recoil cylinder may have a valve in it which permits fluid to pass
freely when the piston is moved in the direction to run out the gun so that at this
time the recoil cylinder has no effect in controlling the movement of the gun-
similarly the piston of the second cylinder may have a valve which allows liquid to
pass when the gun is run back but not when the gun runs forward-or one of the
pistons only might be fitted with the valve.
The small passages by which liquid can pass from one end to the other of the recoil
cylinder can be adjusted separately and quite independently of the passages by which
liquid passes from one end to the other of the additional cylinder.
Two passages may be used for each cylinder and may be at its side-one passage
may be formed so as mainly to control movement at one end of the cylinder, the
other so as mainly to control movement at the opposite end and either passage can
be adjusted independently of the other by shifting a moveable plug within it or in
other convenient way.
Or in place of using two cylinders one to act during recoil and the other during the
running out a single cylinder might be used with two small passages one for allowing
liquid to pass during recoil the other during the running out.
The passages night both be formed along a cylindrical plug fitting a corresponding
cylindrical chamber at one side of the cylinder and parallel with it and either of
them might by a partial turn given to the plug be brought opposite to a slot cut
through from the chamber into the cylinder-a feather or projection on the piston
might work in this slot.
The plug night he turned automatically to bring one of the passages into position
for use when the gun ruus forward and be again turned automatically as the gun
completes its forward movement to bring the other passage into position for acting
when the next recoil takes place.
Or when a single cylinder is used the piston might be formed with passages
through it which are open during recoil but closed by a valve as the gun runs
forward.
To give a uniform pressure in the cylinder during the recoil other small passages
may be formed at the side of the cylinder for the passage of liquid and these may
be made adjustable At the end of the recoil a disc on the piston rod of somewhat

page_text: smaller diameter than the piston may enter a contracted part of the cylinder and
so stop or impede all passage of liquid through the passages in the piston.
As the gun goes forward and the passages through the piston are closed by the
valve above mentioned other passages are opened from one side of the piston to
the other through the piston rod which is made hollow. The passage through the
hollow rod from one side of the piston to the other can be increased or decreased at
different parts of the stroke by a shaped rod passed into the hollow piston rod and
fixed to one end of the cylinder.
Dated this 9th day of November 1889
COMPLETE SPECIFICATION.
Improvements in Apparatus for Controlling the Recoil and Running
Out of Guns.
I, PER NORDENFELT, of 32 Victoria Street, in the City of Westminster, 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:-
In recoil apparatus in which some of the force of the recoil is stored up by the
compression of a spring or otherwise and is at the end of the recoil allowed to at
once run out the gun the recoil is usually controlled by a hydraulic cylinder the fluid
in which has to pass through a small passage or passages in the side of the cylinder
from one side of the piston to the other during the recoil-and power is at the same
time stored by the compression of a spring.
To control the running forward of the gun by the spring at the end of the recoil
I use either a second and independent cylinder which acts only or mainly during the
running out whilst the recoil cylinder acts only or mainly during recoil-or I use a
single cylinder and when the running out takes place I cause the passage in the side
of the cylinder which was used during recoil for allowing liquid to pass from one
side of the piston to the other to be put out of action and another substituted
for it.
Figure 1 is a longitudinal section of recoil and running out apparatus in which two
cylinders are used.
Figure 2 is a side elevation of a gun and mounting to which this apparatus is
applied.
Figure 2x is a cross section through the cylinder used for controlling the running
out of the gun.
Figure 3 is a back elevation-Figure 4 a cross section-Figure 5 a longitudinal
section through the line ab Figure 4 and Figure 6 a longitudinal section through
the line c d Figure 4 of recoil and running out apparatus in which a single cylinder
is used and the passage for allowing liquid to pass the piston during recoil is changed
for another during the running out.
Figure 7 is a side elevation of a gun and mounting to which this apparatus is
applied.
groove
Figures 8 to 10 are views of part of the mechanisın in which is formed the
used for causing one passage to be changed for another. Figure 8 is an end view
of the part. Figure 9 is a section through the line a 6 Figure 8 and Figure 10 is a
face view.
In Figure 1 A B are two cylinders fixed together end to end in a line with one
another. C is a piston rod passing into both cylinders and having upon it a
piston A for the cylinder A and a piston B' fitting a lining which is within the
cylinder B. The piston rod passes out through a stuffing box at the end of the
cylinder A so that its end may be secured to the gun D whilst the cylinders are
secured to the cradle or carriage E within which the gun is free to slide endwise
as shown at Figure 2.

page_text: Within the cylinder A the piston rod C is surrounded by a coiled spring Zone
end of which bears against the end of the cylinder and the other end bears against
a collar C' fixed on the rod-the cylinder is also filled with liquid. Through the
piston A are passages A which are closed by a valve F when the piston rod is
drawn outwards from the cylinder but which are open when the piston is moved
in the opposite direction. Similarly the piston B₁ has passages B² through it
which are closed by a valve G when the piston moves in one direction but not when
it moves in the opposite direction and the valve G opens when F closes and closes
when opens.
When the gun recoils and the piston rod is drawn outwards the spring Z is
compressed and liquid passes from one end of the cylinder to the other through a
slot formed lengthwise through a portion of the side of a thin tube As with which
part of the cylinder A is lined. At the same time liquid passes from one end of the
cylinder B to the other through the passages formed through the piston B as the
valve G then opens freely. At the end of the recoil and when the piston rod is forced
back in the opposite direction by the spring the valve G closes and liquid has to pass
from one end of the cylinder B to the other through a slot B in the side of a
cylindrical lining B³ which is within the cylinder B and the spring is so restrained
from effecting the running out of the gun too quickly. As the valve G closes
the valve F opens and the liquid in the cylinder A has no offect in controlling the
running out.
In order to be able to vary the speed at which the gun is run out at any time
when it may be desired to do so without having to change any of the parts of the
unechanism for others or without having to take the mechanisin to pieces-I mount
the lining cylinder B in such a manner that it can be turned within the cylinder B
and be locked in any desired position. It is closed at its end and has a spindle H
extending from the centre of the end and passing out through a stuffing box Be at the
end of the cylinder B. The outer end of the spindle H has an arm H' fixed upon it
by which it can be turned and through the end of the arm is screwed a screw H²
which when the spindle has been turned into the position desired can be screwed
inwards and its end made to enter any one or other of a number of holes B' formed in
the end of the cylinder B and the lining cylinder B³ will in this way be locked in the
position desired.
Between the cylinders B and B is a cylinder B³ in which are a number of
longitudinal slots B° of different widths as shewn at Figure 2x. This cylinder
is prevented from turning within the cylinder B by a screw pin B1⁰ as shown in
Figure 1.
When the inner cylinder B is turned into such a position that the slot B formed
in it is not opposite to any of the slots B in the cylinder B the area of the passage
by which liquid can pass from one end of the cylinder B to the other is the slot B+.
If the cylinder is turned so that the slot B is opposite to any one or other of the
slots B then the area of the passage is increased by the area of this slot and as the
slots B are of different widths any desired area of passage from one end of
the cylinder B to the other can be obtained.
In the arrangement of apparatus shown at Figures 3 to 10 in which my invention
is carried out with the use of one hydraulic cylinder only, I is the cylinder, J the
piston rod of the piston of this cylinder-this rod is at its end secured to the rear
end of the cradle K of the mounting. The cylinder I is formed in one piece with a
portion of a clamp ring which embraces the rear end of the gun and the cylinder
is in this way fixed to the gun. The gun is free to slide end wise in the cradle as in
gun mountings heretofore made. M is a coiled spring placed around the piston
rod J-I is a slot formed through the side of the cylinder I and opening into a
cylinder N which is alongside of this cylinder and formed in one piece with it.
Ji is a feather or projection on the piston fitting within the slot I and obstructing
the direct passage of liquid from one side of the piston to the other through
the slot.

page_text: O is a cylindrical plug fitting and free to be turned within the cylinder N. In the
side of the plug O is a cavity O¹ which during recoil is opposite to the slot I' and
liquid can pass through it from one end of the cylinder I to the other. Through the
centre of the saine end of the plug O is also a slot 02 within which is a block 0³ of
width somewhat less than the diameter of the plug. During the running out of the
gun the plug is turned as hereinafter described into such a position that the end of
the slot O2 is opposite to the slot I' and then liquid passing from one side of the
piston to the other has to pass through the slot 03 and the area of the passage so left
for the passage of liquid can be controlled by moving the block Os into such a position
as to at this time bring the side of the block nearer to or further from the slot I¹.
To effect this a spindle P is passed through a stuffing box in the end of the cylinder N
and made to extend into a hole formed into the plug O from the centre of its end. This
spindle passes through a slot formed in the block 03 and the portion which pas es
through the block is made eccentric-in this way if the spindle is locked in such a
position that the longer radius of the eccentric is towards the cylinder I then when
the plug is turned into such a position that the slot O2 is opposite the slot 1 the block
will be brought into comparatively close proximity to the mouth of this slot and the
area left for the passage of liquid will be small but if the spindle is locked in position
with the smaller radius of the eccentric towards the slot the space between the side
of the block and the mouth of the slot I will be large. In order to be able to turn
the spindle into any position desired the end of the spindle has fixed upon it a disc P¹
the disc carries a spring bolt P the end of which can be made to enter any one or
other of a number of small holes N¹ in the end of the cylinder N and so the spindle
can be locked in any position desired.
The way in which the plug O is turned so as during recoil to have the cavity O¹
opposite the slot I' and during the running out to have the slot O2 opposite to this slot
is as follows.
The opposite end of the plug O to that which has the spindle P passing into it is
made to pass out through a stuffing box in the end of the cylinder N-this end of the
plug is hollow and has extending into it a rod Q which is fixed to the cradle K. The
rod at its inner end has a pin R thrust out froin its side by a spring R'. The pin
enters a groove cut in the side of the hollow in the plug or rather cut in the segment S
of a cylinder which lies in a corresponding recess inade at the side of the hollow
in the plug. Various views of this segment of a cylinder are shewn at Figures 8, 9
and 10.
As will be seen one part S' of the groove is straight and parallel with the axis of
the plug the stud travels along this part of the groove during the greater part
of the recoil. The groove gradually decreases in depth as shown at Figure 9 until
at Sit suddenly again becomes of the original depth and is also made to incline some-
what to the axis of the plug as shewn at Figure 10 and then for a short distance S³
the groove is again made straight.
At S the straight portion S3 of the groove branches in two directions one into the
straight portion S₁ and the other into a short inclined groove S'which at its end opens
into a straight portion So which is parallel with the straight portion S¹. At the end
of the straight portion S' is another short inclined groove Se leading into the
portion S¹ at some little distance from its end. The straight portion S like the
straight portion S₁ is made gradually to decrease in depth and the inclined con-
tinuation Se of the shallow end of the groove is made of this same shallow
depth.
When recoil takes place the pin R moves along the straight portion S' of the
groove and is gradually forced back somewhat into the rod Q as the groove S¹
decreases in depth. At S the pin R again springs out into a deeper portion of the
groove and the groove being slightly inclined at this point the plug
has a slight
turn given to it and then for the remainder of the recoil the pin R. travels along the
straight portion S. Afterwards at the commencement of the running out of the gun
the pin R travels back along the straight portion S* until it comes against the

page_text: shoulder S and then as it cannot ride over this shoulder it must necessarily enter
the inclined portion S' the plug is consequently made to turn through a considerable
angle and then for the greater part of the remainder of the running out it is retained
in the position into which it has been turned by the pin R travelling along the straight
portion S. Near the end of the running out the pin R enters the inclined portion So
of the groove and the plug is consequently turned back to its original position. As
the pin passes along the straight portion S and inclined portion So it is gradually
pressed inwards by the decrease of depth of these grooves but so soon as the pin passes
out of the inclined portion Se it springs out again and enters the straight portion S'
which is here of its full depth.
In Figures 3 and 4 the lower portion L'of the clamp which embraces the gun and
which has the cylinders I and N formed in one piece with it is shewn to be also
forined with a passage V through it which is to form a bearing for an axis by which
the breech mechanism of the gun is to be opened and closed-but as my present
invention does not relate to breech mechanism no breech mechanism is shown in the
drawing.
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. Apparatus for controlling the recoil and subsequent running out of guns, in
which a spring is compressed during recoil and the recoil and subsequent running out
is controlled by two separate and independent cylinders each having its own side
passage and filled with its own supply of liquid and one acting only during recoil and
the other only during the running out and in which the area of the passage in the
cylinder which controls the running out can readily be varied from the exterior
without its being necessary to take the mechanism apart and without varying the
resistance offered during recoil.
2. The construction of apparatus for controlling the recoil and running out of guns
substantially as hereinbefore described with reference to Figures 1, 2 and 2x.
3. Apparatus for controlling the recoil and subsequent running out of guns, in
which a spring is compressed during recoil and the recoil and subsequent running
out is controlled by a single cylinder filled with liquid and two passages at its side,
one of which can be brought into position to allow of liquid passing the piston from
one end of the cylinder to the other when the gun recoils and the other brought into
position to allow fluid to pass the piston during the running out.
4. The combination of the gun, the gun cradle, the cylinder I fixed to the gun,
the piston fitting this cylinder, its piston rod J fixed to the gun cradle the spring M
contained within the cylinder and bearing against the piston the slot I' formed
along one side of the cylinder and opening into a cylindrical casing N and the
cylindrical plug O contained within this casing and having two grooves formed along
its sides one of which is brought in front of the slot I' before recoil takes place and
the other during the running out.
5. The combination of the gun, the gun cradle, the cylinder I fixed to the gun,
the piston fitting this cylinder its piston rod J fixed to the gun cradle the spring M
contained within the cylinder and bearing against the piston- the slot I' formed along
one side of the cylinder and opening into a cylindrical casing N,the cylindrical plug Ổ
contained within this casing, the two grooves O¹ 02 formed along it, means for
bringing one groove in front of the slot I before recoil takes place,and for bringing the
other in front of the slot during the running out and the eccentric P and sliding
block Os for adjusting the area of the passage O².
6. The combination of the gun, the gun cradle, the cylinder I fixed to the gun,
the piston fitting this cylinder, its piston rod J fixed to the gun cradle, the spring M
contained within the cylinder and bearing against the piston-the slot I' formed
along one side of the cylinder and opening into a cylindrical casing N, the
cylindrical plug O contained within this casing, the two grooves 01 02 formed along

page_text: it and the fixed rod Q spring pin R and groove S1 S2 S3 S4 S5 and S* formed
along the sides of a cylindrical recess in the plug O to turn the plug at the times
required.
This sch
ST. 1000