Improvements in Cornets and similar Brass Wind Musical Instruments.
Year: 1897

page_text: Date of Application, 2nd Dec., 1897-Accepted, 12th Feb., 1898
COMPLETE SPECIFICATION.
Improvements in Cornets and similar Brass Wind Musical
Instruments.
I, DAVID JAMES BLAIKLEY, of 13, Elsworthy Terrace, Primrose Hill, in the
County of Middlesex, Musical Instrument Maker, 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 cornets and other brass wind musical instruments of the
kind or class in which three or four piston-valves are used for the purpose of
producing the chromatic scale.
In such instruments, a ring or annular piece of cork is usually fitted into the
top cap of each valve to serve as a cushion for the head of the piston-spindle and
thus prevent noise or jar when the piston is depressed. These cork rings or
cushions have hitherto been fitted into a recess formed by enlarging at its upper
end the hole through the said cap in which the piston-spindle works. The cork
ring or cushion is, therefore, only supported on the exterior by the metal of the
cap, and consequently is liable to be easily pressed down or deformed so that
it will no longer stop the piston in its downward movement in the proper position
to ensure the coincidence of the passages through the piston or pump with those
through the core-tube and pump-case. Moreover should the piston-spindle be
slightly bent, it will bear directly against the cork and will consequently have a
sluggish return or upward movement.
The main object of my present invention is to obviate these defects, and for
this purpose I form in the upper side of the top cap and concentrically with the
hole through which the piston-spindle passes, an annular groove which is preferably
made with its outer wall or inner wall or both of its walls more or less undercut,
and I force the cork ring into this groove in any convenient manner. When thus
fitted into the cap, the cork ring is firmly supported on the interior as well
as on the exterior by the metal of the said cap, and is therefore not liable to be
pressed down or deformed as heretofore, but is much more rigid, while it serves
equally well or better as a cushion for the purpose above specified.
My improved cap can be advantageously employed in conjunction with the cork
washer which is usually placed upon the spindle of the piston beneath the cap,
to serve as a cushion for the piston at the termination of its return or upward
movement.
In some instances, however, I fit a cork ring in an annular groove formed in the
manner above described in the underside of the cap.
In other instances I form an annular groove, with one or both of its walls
undercut, in the top of the piston, concentric with the spindle thereof, and
force a cork ring into the said groove.
In the accompanying drawing
Figure 1 is a sectional elevation of a piston-valve with my improvement applied
thereto.
Figure 2 is a similar view illustrating a modified construction of the top cap, and

page_text: Figure 3 is a similar view of a piston or pump removed from the core-tube or
pump-case, showing a further modification of my invention.
is the pump-case with its core-tube; b is the piston or pump; c is the top
cap having a central hole c' in which works the spindle b' of the piston; d is the
ring or annular piece of cork.
It
In the upper side of the cap c is formed an annular groove e concentric with the
hole and with its exterior wall undercut so as to securely retain in place the
cork ring d, which is forced into the said groove in any convenient manner.
will be seen that the said cork ring d is supported by the inner wall as well as
by the outer wall of the groove e, and, therefore, cannot be crushed or squeezed
inward against the spindle of the piston like the cork rings as hitherto fitted
in the top cap. Moreover the spindle b', should it be slightly bent, will bear
against the metal of the cap and not against the cork ring as heretofore, and con-
sequently any such bending of the spindle will be at once detected.
In the form of construction shown in Figure 1, the piston is provided with
the usual ring or washer f of cork resting upon the top of the piston and
surrounding the spindle & thereof.
In the modification of my invention shown in Figure 2, instead of the usual
cork ring or washer f, 1 employ a ring or annular piece y of cork, which is forced
into an undercut groove e formed in the underside of the cap c.
Figure 3 shows a further modification of my said invention, in which I force a
ring or annular piece of cork into an undercut annular groove ; formed in the
top of the piston b around the spindle thereof. This form of piston can be used
with a cap constructed either as shown in Figure 1 or as shown in Figure 2. The
cap shown in Figure 1 is, however, sufficient for all requirements.
Although it is more advantageous to make the aforesaid annular grooves with
one or both of their walls undercut for the purpose above specified, I can, if desired,
make the walls of the groove parallel with each other and, if necessary, secure the
cork ring therein by means of cement or the like.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declaro that what I
claim is:-
First. A top cap for the piston-valve of a cornet or similar brass wind musical
instrument, in which the cork ring or cushion is secured in an annular groove
formed in the upperside of the said cap surrounding the hole in which the piston-
spindle works (with or without the ring or annular piece of cork secured in an
annular groove in the underside of the said cap), substantially as, and for the
purposes, herein before described.
Second. A piston or pump for a cornet or similar brass wind musical instrument,
having a ring or annular piece of cork secured in an annular groove formed in
its upper end around its spindle, substantially as described with reference to
Figure 3 of the drawing for the purpose above specified.
1200
затоп LA
Decemur
BAYAN NA Z
AJAY BE DecemUEL LO
D. YOUNG & Co.,
11 and 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.