Improvements in and relating to Pneumatic Power Hammers.
Year: 1895

page_text: Date of Application, 24th Oct., 1895-Accepted, 21st Mar., 1896
COMPLETE SPECIFICATION.
Improvements in and relating to Pneumatic Power Hammers.
I, JEAN BÊCHÉ Jr., of Hückeswagen, in the Province of the Rhine, German
Empire, Manufacturer 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 :-
This invention refers to pneumatic hammers of that kind, in which the ram, rammer
or monkey is formed by a cylinder containing a piston, and in which said cylinder is
operated from said piston by the mediation of air, that is enclosed within the said
cylinder above or below the said piston. There are in a hammer of said kind the
movements or blows of the ram, rainmer or monkey, i.e. of the cylinder, dependent
on the movements of the piston, and the latter is to he set going or is to be stopped
if the cylinder is to strike or is not to strike. Owing thereto, the regulation of
the number of blows, and of their strength, is in hammers of the said kind a difficult
one ;.
My improvements in the machines in question relate to means for doing away with.
the drawbacks mentioned at the end of the foregoing paragraph, and I attain that
object by the construction shown in the accompanying drawing, in which the guide-
piece a for the monkey b is formed into a cylinder, and in which the cross-head c for the
piston-rod d is formed into a piston adapted to move up and down within said
cylinder a. There are thus in my improved machine two pistons connected by a
common rod, and moving simultaneously upwards and downwards without altering
their relative distance. The upper (c) of said pistons forms together with the
monkey b a chamber e.
lateral tube-like extension a¹ of the cylinder a serves as a casing for a plug f,
which may be turned from the shaft g by the mediation of the lever hand the
link i. The shaft 9 is for that purpose provided with a handle y'. The plug f
forms in its upper part a seat for a valve k which is acted on by a spring
constantly tending to close said valve. It is thus to be seen, that air may be
forced out of the chamber e at any time, but can be sucked in only if the cock a' f
is open.
Supposed, the cock be open, the monkey b will be raised and lowered, i.e.
as will be clear without
caused to strike, at every stroke of its piston 6',
further explanation to every one versed in the art in question. If, however, the
monkey to cease striking, the plug f is turned so as to close the air-channel a¹,
when the further action will be as follows:-
The piston c moving (rapidly) upwards causes the air contained within the
chamber to rarefy, whereas the air contained within the monkey babove
the piston is compressed by this piston. Owing the rapid movement of the
piston 6, the degree of compression of the air is very strong, and the monkey is
suddenly thrown upwards with a considerable force, the more, as the air within
the chamber e is in a rarefied state. In consequence of the compression on one
side, and the rarefication on the other side, the powerful upward movement of
the monkey continues after the same movement of the piston 6' has ceased, and
a corresponding part of the air contained within the chamber e is thus driven
out through the valve k. The space finally remaining between the piston c and
the monkey in the highest position of the latter is, in fact, only a seventh or an
eighth of what it was in the lowest position of said two parts.

page_text: The piston c, and consequently the piston 6, too, do never stop in their
reciprocating motion; there is, however, the difference that the strokes of, said two
pistons are unvariably of the same length, whereas the strokes of the monkey
become considerably shorter after the cock f has been closed, said latter strokes
being then so short, that a comparatively great distance remains between the anvil
and the monkey in the lowest position of the latter. The space between the
monkey and the piston c does not, as a matter of course, remain as small as
described at the end of the foregoing paragraph, but, on the other hand, said
space does not again become as large as it formerly had been, the rarefaction on
one side and the atmospheric pressure on the other side hindering the monkey from
assuming its proper lowermost position.
The monkey regains this latter position, i.e. begins again to strike, as soon as the
cock fis opened. If said cock is fully, or nearly fully, opened, the strength of the
blows of the monkey will be the greatest attainable one; if, however, the cock is but
slightly opened, the strength of the blows will be correspondingly decreased, the
degree of strength being dependent upon the degree of opening of the cock. The
monkey follows the movements of the cock f, or of the handle respectively, with
remarkable exactness, and the number of blows, as well as their strength, may be
regulated perfectly at will.
The construction of the piston is old, but for the sake of completeness I will
give a short explanation of the purpose of the channels and ball-valves arranged
within said piston.
The piston-rod d contains a channel d', which is at its lower end constantly
closed by a ball-valve m (the ball of which is preferably supported by a spring), and
opens at its upper end by any suitable aperture (not shown) into the atmosphere.
Said channel d communicates by the angular channel 62 with the chamber above
the said piston 6, but said communication is normally interrupted by a ball-valve m¹
arranged in the upper part of said channel 6 2.
The purpose of the arrangements just described is to prevent the arising of a
vacuum in either of the chambers of the monkey b. If, for instance, the piston bis
caused to remain for rather long a time in its upper position, the air contained, and
compressed, within the upper chamber of the monkey will slowly be forced away
by the weight of the latter; when, thereafter, the machine is to work again, and the
piston b is to move away from the upper part of the monkey, there then occur in
proper working of the machine disturbances resulting from the vacuum in the
upper chamber of the monkey b. Such disturbances are effectively avoided by the
use of the valve m', in that in the case afore stated air may enter the empty space
through the channels d' 62, but cannot leave that space through these channels.
Just the same is the case with the lower chamber of the monkey b and the
valve m, and I think I may after the explanation afore given abstain from repeating
the
the same.
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 pneumatic hammer having as a monkey a cylinder operated by a piston
arranged within said cylinder, the combination with the said cylinder or monkey, of
another cylinder forming a guide for said monkey, and of another piston connected
with said former piston, and moving within said other cylinder; means for rarefying
the air contained within the space between the said monkey and said other piston,
for the purpose as described.
2. In a pneumatic hammer having as a monkey a cylinder operated by a piston
arranged within said cylinder, the combination with the said cylinder or monkey,
of another cylinder forming a guide for said monkey, and of another piston connected
with said former piston, and moving within said other cylinder; two valves adapted
to put the air connected within the space between the said monkey and said other
piston into. intercommunication with, or disconnect it from, the outer air; one of

page_text: said valves being operated by said first-mentioned air, the other compulsorily, for the
purpose as described.
3. In a pneumatic hammer having as a monkey a cylinder operated by a piston
arranged within said cylinder, the combination with the said cylinder or monkey,
of another cylinder forming a guide for said monkey, and of another piston
connected with said former piston, and moving within said other cylinder; a valve
or plug adapted to put the air contained within the space between the said monkey
and said other piston into intercommunication with, or disconnect it from, the outer
air; another valve arranged within or upon said former valve, and adapted to be
actuated by the air contained within said space; means for operating the said former
valve compulsorily, substantially and for the purpose as described.
Dated the out andahan 100K
JEAN BÊCHÉ, Jr.,
By Geo. H. Rayner,
37, Chancery Lane, London, Agent for the Applicant.