Improved Method of and Apparatus for Compressing Air and other Fluids for Use in Guns, and for other Purposes.
Year: 1889

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c. Act, 1883) as allowed by
the decision of the Comptroller General, of the 11th day of June 1898.
Date of Application, 23rd July, 1889-Accepted, 24th Aug., 1889
COMPLETE SPECIFICATION (AMENDED).
Improved Method of and Apparatus for Compressing Air and other
Fluids for Use in Guns, and for other Purposes.
I, CHRISTIAN ALBERT JENSEN, of 77, Chancery Lane, in the County of London,
Patent Agent, 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, (a communication to me from abroad by Dana Dudley,
Engineer, of Lynn, Essex County, Massachusetts, United States of America):
I have herein described this invention as applied to an improved pneumatic
gun provided with a separate compartment, in which the air-compression is
produced, connected by suitable tubing with the gun barrel from which the
projectile is to be discharged.
The accompanying drawing which illustrates the said invention is a vertical
cross-section through a gun showing its different parts.
A is the air-compression chamber, having a removable breech-piece B of well-
known construction and provided with firing mechanism B¹. C is the explosive.
D is a diaphragm of metal or other suitable material, closing the end of the
explosion chamber and held in place by means of the cap EE, which screws onto
and partly over the end of the air-compression chamber A. This diaphragm D
when thus secured in place tightly closing the chamber A acts as a pressure safety
valve, the resistance of the diaphragm providing one means for determining the
degree of pressure that can be produced within the chamber. This required degree
of resistance may be attained either by variation in the thickness of the diaphragm
or in its material. FF is an air tube open at both ends which connects the
compression-chamber A with the barrel G of the air gun, in the rear of the
projectile H as shown. I is the breech-piece removable for the purpose of intro-
ducing the projectile, and K K are braces to hold the parts together.
The operation of the gun is as follows:
The gun having been loaded as shown in the drawing, with the projectile in
barrel G forward of the entrance of the air tube F and the explosive in chamber A,
the breech-pieces B and I are closed, and the diaphragm D firmly secured in place.
On the explosion of the explosive C by means of a primer, or in any well-known
way, the contained air is at once greatly compressed and this pressure com-
municated through tube F to the rear of the projectile in barrel G discharging the
gun.
A gun
of the following dimensions will give good results, in which the diameter
of the bore proper (barrel G) is 14 inches, length 84 inches: diameter of air tube
(tube F) is 2 inches, length 40 inches: diameter of air-compression chamber (A)
is 3 inches, length 38 inches: weight of projectile is 2 lbs. of powder charge 8.oz.,
and the resistance of plate D to blowing out 45 lbs. per square inch. But I do

page_text: not limit myself to the dimensions here given as each and all of them may be
greatly varied without departing from the essence of the invention.
Among numerous advantages presented by the improved gun are the great
simplicity and consequent cheapness of construction, the facility with which the
air-pressure is produced and the absence of any fouling of the gun barrel due to the
smoke and unburnt powder.
It is evident that the explosive charge and the gun barrel G remaining un-
changed the pressure in the latter may be regulated by varying the size of
chamber A it is also evident that while I have shown chamber A in the drawing
in the shape of a tube open at both ends and with the necessary closing devices,
a form which is greatly preferable because of the increased facility it affords for
cleaning the chamber, I do not limit myself to the same, as the chamber may be
of any convenient shape, provided always that it has means for the introduction
of the explosive, and for connecting it with the barrel containing the projectile.
Neither do I limit myself to the particular location with respect to each other of
the compression-chamber A and of the gun-barrel G; these are shown in the
drawing as being in a vertical plane, but they may also be in a horizontal plane,
or even disconnected in every respect until the moment of firing.
It is also obvious that other ways of firing the explosive may be used from that
shown in the drawing.
I do not limit myself to the use of air alone as the clastic agent in performing
the work, as gas or gases of greater or less density may be used without departing
from the spirit of my invention.
Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed, I declare that what I
claim, as communicated to me from abroad by my correspondent, is:
1. The method of discharging projectiles by means of the explosion of an
explosive, consisting in interposing a column of air uninterruptedly between
the projectile and an explosion chamber and then exploding an explosion in said
chamber, whereby a high pressure is developed and the projectile discharged,
substantially as described and shown in the accompanying drawing.
2. A pneumatic gun consisting of an air-compressing chamber adapted to con-
tain air to be compressed by an explosive therein, a barrel to contain the projectile,
means for communicating the air pressure to the projectile in the barrel, means for
charging the air compressing chamber and the barrel and means for exploding
the explosive in the air compressing-chamber, substantially as and for the
purpose described.
3. The combination of chamber A, adapted to contain air to be compressed by an
explosive therein, having a breech-piece B, an explosive contained in said chamber
and firing mechanism, barrel G having the breech-piece I and connecting tube F
substantially as and for the purpose set forth.
4. The combination of chamber A adapted to contain air to be compressed by
an explosive therein and having the breech-piece and firing mechanism for ex-
ploding the explosive, diaphragm D and cap E closing the explosion chamber,
barrel G, having the breech-piece I, and tube I connecting chamber A with
harrel G in the rear of the projectile, substantially as and for the purpose
described.