Improved Methods of Testing Percussion Caps and the Apparatus therefor.
Year: 1892

page_text: Date of Application, 7th July, 1892
Complete Specification Left, 7th Apr., 1893-Accepted, 17th June, 1893
PROVISIONAL SPECIFICATION.
Improved Methods of Testing Percussion Caps and the Apparatus
therefor.
1
I, WILLIAM DALRYMPLE BORLAND, of Beacon Lodge, Green Street Green,
in the County of Kent, Analytical Chemist, do hereby declare the nature of this .
invention to be as follows:-
My invention consists essentially of improved methods and apparatus for testing
percussion caps in respect to:
(1.) Sensitiveness to blows of varying and accurately determined degrees of
intensity.
(2.) Effect of shape and size of striker.
(3.) Effect of variations in respect of the direction of the blow delivered by the
striker on-the cap.
(4.) Explosive force of cap.
་
(5.) Time between delivery of blow on striker and ignition of cap.
(6.) Comparison of igniting power of caps.
The apparatus consists of a heavy base on which is erected a rigid graduated
standard carrying a sliding clamp which can be fixed at any desired point.
The clamp has attached to it means for holding a weight and releasing the same
so that it falls upon the centre of a striker resting upon the cap to be tested, which
cap is held in position in a holder on the base of the apparatus.
The weight is preferably held and released by the use of an electro-magnet, or
by the use of a small clutch actuated by pneumatic release.
Provision is made for fixing the cap at any desired angle with the striker, so
that the blow may always be delivered on the centre of the cap by supporting the
cap or cartridge on wedge shaped rings of different inclinations.
In testing the explosive force, the cap is fixed gas tight upon the end of a tube
clamped in the base of the apparatus. An accurately fitting plunger carrying a
knife upon its lower end works in the tube, and the force exerted by the explosion
is measured by gauging the cut which the knife makes on prepared cylinders or
blocks.
In time tests the striker is made to enter one circuit of an electrical chronograph,
and the movement of the striker under the falling weight interrupts the current.
The second electrical circuit of the chronograph is closed by means of a spring
or other contact such, for example, as a weighted lever held in position by a
fragment of some explosive material placed in the path of the flash from the cap.
The explosion of the cap ignites the said fragment, and the spring being thereby
released, interrupts the chronograph circuit and the registration is made in the
usual way.
In comparing the igniting power of various caps, a small charge of explosive is
carried in a cup or on a plate placed in the path of the flash with adjustment for
varying the distance between explosive and cap, so as to determine the maximum
distance at which certain ignition can be obtained.
Dated this 7th day of July 1892.
.
W. H. MUNNS,
Agent for Applicant.

page_text: COMPLETE SPECIFICATION.
Improved Methods of Testing Percussion Caps and the Apparatus
therefor.
I, WILLIAM DALRYMPLE BORLAND, of Beacon Lodge, Green Street Green,
in the County of Kent, Analytical Chemist, 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 consists essentially of improved methods and apparatus for testing
percussion caps in respect to :
1. Sensitiveness to blows of varying and accurately determined degrees of
intensity.
2. Effect of shape and size of striker.
3. Effect of variations in respect of the direction of the blow delivered by the
striker on the сар.
4. Explosive force of cap.
5. Time between delivery of blow on striker and ignition of cap.
Fig. 1. is a view of machine arranged to test the explosive force of cap.
Fig. 2. is a separate view of striker R.
Fig. 3. is a view of tube S with plunger T inserted.
Fig. 4. is a view of cylinder O holding cap and bush.
Fig. 5 is a top view of bush P holding percussion cap Q.
Fig. 6 represents crusher T¹ with lead cylinder W on support X.
Upon a strong base A furnished with levelling screws B are erected columns C
supporting bracket D. The bracket D carries the graduated standard E hinged
at F so that it may be fixed at any desired angle with bracket. D. On the
standard E is sliding clamp J with set screw J carrying bracket K¹ supporting
electro-magnet K and also a small fork M with set screws M¹ for assisting in
steadying weight L. The clamp G with set screw G' holds the tube H which
secures the weight L when it has fallen. N is a cover hinged or screwed on to a
hollow cylinder O, which is not shown in Fig. 1. This cylinder O passes through
and fits into an orifice in bracket D, the notch O³ fitting into a guiding stud on
bracket to prevent twisting of O. The set screw Of secures O in position.
Secured to the under side of bracket D are screw rods C². The frame A¹ ending
in rings A² encloses these rods and the plate B¹ is secured to the said rods by
screws C¹. Through this plate B is screwed the hollow screw V with milled
wheel U. The striker R passes through cover N the wider part of R in its lowest
position resting upon an internal collar of N and the bottom of narrow end touching
cap Q. The bush P holding cap Q accurately fits into O and rests on an internal
collar of O. The tube S is so shaped at its upper end S2 that when forced up by
screw V it makes a gas tight fit with the base of the cartridge or bush holding cap.
This fit can be assisted by the use of an elastic wad or the use of some lubricant
material. The shoulder of S rests on screw V. The plunger T moves in tube S,
the knife edge of T resting on lead cylinder W, which is supported by head X
attached to screw Y, which itself is screwed in to Z a movable piece fitting into
cavity Z of base A. In order to accurately fit the cartridge or bush holding the
cap Q, movable rings S₁ of various diameters can be put on the tube S, or tubes of
different diameters can be provided to suit different sizes. D', D' are electric
wires to K and D2, D2, are contact makers.
The tube S is forced up by screw V till it makes a gas tight fit with the
cartridge or bush P. When the circuit is complete the weight L is held
suspended from the electro-magnet K immediately over the striker R. When
the current is interrupted the weight L falls upon the striker R. The lower end

page_text: of striker R by impact upon cap Q causes it to explode. The only escape of the
gas of explosion is downwards in tube S on to the top of plunger T. The edge
of T is thus forced into the lead cylinder W. The explosive force of the cap Qis
estimated by the amount of the cut into W. It is found convenient to have the
knife edges at an angle of 60° to each other. The cut can be accurately gauged
in the following manner as shown in Fig. 9. In an ordinary micrometer caliper
the measure is taken of a perfect lead cylinder W and model knife T2 with edges
corresponding to those of T. When the cut cylinder W is put in the caliper with
the same measuring knife T' the difference of the gauge will be the measure of
the cut.
If it is desired to estimate the explosive force by the crushing effect, X and Y
are removed and the screw X' with flat head substituted. The lead cylinder W
is placed upright on its base and a plunger T' with flat head substituted for
plunger T.
To ensure that the weight L shall fall vertically on to the striker R, a light
steel rod is suspended previously from the magnet K and the machine adjusted till
the point of the rod coincides with the centre of the striker R.
Fig. 7 shows the upper part, and
Fig. 8 the lower part of the apparatus employed in time tests.
The plunger T, cylinder W & supports are removed and the lower part of the
apparatus as shown in Fig. 8 placed on the base A. It is desirable also to replace
tube S by a similar one which is to be used when the plunger T is not inserted, as
the gases rapidly corrode and spoil the tube when used without a plunger. To
striker R is attached a metallic rod E'. One circuit of an electric chronograph is
closed by screw F' on rod E¹. When the striker R is struck by the falling weight
the rod E' is moved from contact with screw F1 and the circuit interrupted. In
the path of the flash of the exploded cap a thread H¹ of gun cotton or other
explosive material holds a bent lever L1, L2 so as to make contact with screw P¹,
and so complete the second circuit of the chronograph. The lever L', L² is fulcrumed
at N. Qis a weight sliding on L2, and R₁ a graduated rod. The explosion of
the cap ignites the thread H¹, the arm L² consequently falls from contact with
screw P, and the second current is thus interrupted.
It is obvious that the arrangement of the apparatus shown in Figs. 1 to 6, and 9,
serves to test the effect produced by different weights, and by strikers of different
shape and size.
In comparing the igniting powers of caps, the plunger T and movable parts
below are removed, and a small charge of explosive is carried in a cup or on a
plate placed in the path of the flash with adjustment for varying and recording the
distance between said explosive and cap.
To judge whether a proper detonation is effected the flash may be received on
paper and the amount of residue and charring observed.
In order to estimate the effect of variations in respect of the direction of the
blow delivered by the striker on the cap the cover N is removed and the
apparatus shown in Fig. 10 is used. N2 is the substituted cover screwed or hinged
on to cylinder O carrying bush and cartridge. N2 has a wide opening at top
shaped as shown. In this opening moves the ball U₁ furnished with a projection
above and a diametric opening to receive the striker R. The striker R is placed
at the required angle to the cap, and the apparatus of Fig. 1 adjusted so that the
striker R is in the vertical. The standard E is also placed in the vertical so that
the weight L falls directly on to the striker R. Fig. 11 shows a pneumatic release
which can be used instead of the electric magnet K. V' is a pneumatic tube
supported at top by bracket K. W' is a piston moving in the tube VI and
attached to one arm of a lever Y¹ fulcrumed at Z2. The other arm of lever Y¹
ends in a catch Z³ holding weight L. The tube V' ends in a ball. When the
ball is pressed the air in tube V lifts up the piston Wand removes the
catch Z³ from the weight L which accordingly falls.

page_text: 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. In a percussion cap testing machine the striker R, the tube S for making a
gas tight fit with the cap holder, and the plunger T furnished with a knife edge in
combination with a weight delivering apparatus for the purpose of testing the
explosive force of caps.
2. In a percussion cap testing machine the striker R, the tube S for making a
gas tight fit with the cap holder, and the plunger T¹ furnished with a flat head in
combination with a weight delivering apparatus for the purpose of testing the
explosive force of caps.
3. The apparatus substantially as described and shown in Figs. 1-5, for the
purpose specified.
4. The special form of tube S as described and shown in Fig. 6 for the purpose
specified.
5. In a percussion cap testing machine the striking apparatus described and
shown in Fig. 1 with the time testing apparatus described and shown in
Figs. 7 & 8.
6. In a percussion cap testing machine the apparatus for varying the direction
of the blow given by the striker on the cap substantially as described and shown
in Fig. 10.
7. In a percussion cap testing machine the apparatus for releasing the weight
substantially as described and shown in Fig. 11.
Dated this 7th day of April 1893.
W. H. MUNNS,
Agent for Applicant.