Improvements in Pneumatic Hammers and Valve Mechanism therefor.
Year: 1896

page_text: Reprinted as amended in accordance with the decisions of the 10th Nov. 1897,
25th Oct. 1898, and the 20th day of July 1908.
(The amendments are shown in erased and italic type.)
Date of Application, 29th Oct., 1896-Accepted, 10th July, 1896
COMPLETE SPECIFICATION (AMENDED).
Improvements in Pneumatic Hammers and Valve Mechanism
therefor.
I, JOSEPH BOYER, of Saint Louis, Missouri, United States of America, Machinist,
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 present invention relates to machines of the general nature of that hereto-
fore patented to me by Letters Patent No. 7,672, of April 16, 1895. The first and
principal feature of my present invention relates to the valve mechanisın, by
which the movements of the piston are controlled. It is highly desirable, for
purposes of convenience in handling the tool when at work, that the bodies of
tools of this character shall be made as short as can be done consistently with
the length of stroke which it is necessary to give the piston in order that the
latter may act with sufficient power upon the chisel or other working tool ein-
ployed with the hammer. Inasmuch as the force of the blows delivered by the
piston at any given pressure of motive fluid depends mainly upon its weight and
length of stroke, it is desirable that it shall be heavy and that it shall have as
long a stroke as possible. But it is also desirable that the body of the tool shall
not be of excessive diameter, and weight must therefore be added to the piston by
increasing its length, rather than its diameter. Under these conditions, therefore,
it follows that increased power in the tool is to be attained chiefly by increasing
the length of the piston chamber, to accommodate long strokes of a long piston,
and a piston chamber of maximum length consistent with the length of the tool
as a whole is therefore essential to improvement along these lines. It is the
principal object of the novel valve mechanism constituting the first feature of
my present invention to accommodate a piston chamber of increased length
without increasing the length of the tool as a whole, and to thereby permit a
greater length of stroke of the piston in a tool of given length, and conse-
quently increase the power of action of tools of this character. In the tool
shown and described in my aforesaid patent, and in many other tools
of this character which have been patented and some of which are in
practical use, the valve has been arranged in a separate chamber immediately in
rear of the piston chamber, between the latter and the handle or head of the tool,
with the result that this interposition of the valve in a separate chamber at the
rear end of the piston chamber and in line with the latter has necessarily diminished
the possible length of the piston chamber by the amount of space occupied by the
valve chamber and valve, and has consequently diminished to that extent the
possible length to be given the stroke of the piston in any tool of given length. In
the novel valve mechanism of my present tool the valve consists of a cylindrical

page_text: shell arranged within the piston chamber itself and of a sufficient internal diameter
to surround the piston and permit it to pass entirely through the valve. This valve
is preferably located in the rear end of the piston chamber, so that the piston passes
through and is surrounded by the valve at the end of its rearward stroke, as
illustrated in the drawing and hereafter described, but this particular location of
the valve is not essential to the broader scope of my invention, as will be apparent
from the description thereof hereinafter given, and from the terms of my respec-
tive claims. It results from this construction and arrangement of the valve that
the space occupied by it does not diminish the length of the piston chamber at all,
since the piston chamber extends entirely through the valve, and it therefore
follows that a tool of given longth will accommodate a piston chamber as much longer
than the piston chambers of the prior tools above referred to as the length of the
space occupied by the valve chamber and valve in such prior tools, thereby per-
initting greater length of stroke for the piston and correspondingly increasing the
force of its blows and the power of action of the tool.
Another feature of my present invention consists in a construction whereby the
inner end of the shank of the chisel or other working tool itself forins the means
for closing the front end of the piston chamber and constitutes a part of the cylin-
der head or abutment against which the motive fluid admitted to the front end of
the piston chamber acts in driving the piston rearward.
Another feature of the invention relates to a novel locking device for the
coupling sleeve which holds the parts of the tool together; all of which features
will be hereinafter more fully explained by reference to the accompanying drawings,
in which Figure 1 is a longitudinal section of my new tool, with part of the handle
left in elevation, and with the piston at the forward end of its stroke and the valve
in corresponding position; Figure 2 a view corresponding to Figure 1, with the
handle of the tool broken off, and with the piston near the rear end of its stroke,
and with the valve in corresponding, position; Figure 3 a perspective view of the
valve itself; Figure 4 a vertical section of the valve block and valve, with the valve
in the position shown in Figure 1; Figure 5 a corresponding view with the valve
in the position shown in Figure 2; Figure 6 an elevation of the rear face of the
valve block, (the right hand face of the block shown in Figures 4 and 5); Figure 7
a sectional detail illustrating the locking device heretofore referred to, and Figures 8
and 9 further details of the same, and Figure 10 a sectional detail of a modification.
Of the several views Figures 3 to 8 correspond in size to the tool from which
the drawing was made, while Figures 1 and 2 are approximately two-third such
size.
The same letters of reference are employed to represent corresponding parts
in all the views.
The cylinder or barrel A of the tool is provided at its rear end with an annu-
lar flange B over which fits a coupling sleeve C provided at its front end with
an internal flange abutting against the flange B on the cylinder, and externally
threaded upon its rear portion to screw into the interiorly threaded cap D pro-
jecting froin the cylinder head or handle base E, such head or base having the
grasping handle F of the tool formed integral with it. The supply duct G for
the motive fluid extends through the handle F and is controlled by a throttle
valve operated by a thumb lever H, as in my aforesaid patent. Located within
the cap D and rear end of the coupling sleeve C, and clamped by them between
the rear end of the cylinder A and the head E, is the cylindrical valve block I
hereinafter more particularly described. Suitable dowel pins interposed between
the rear end of the cylinder A and forward side of the valve block I, and between
the rear side of the valve block and the cylinder head or handle base E, hold
the cylinder, valve block, and head E in position and prevent turning of thein
relatively to each other. The novel lock which co-operates with the coupling
sleeve to prevent unscrewing of the latter will be hereafter described. The
portion of the piston chamber within the cylinder A consists of a straight cylin-
drical bore whose rear end opens at its full diameter through the rear end of

page_text: the cylinder A, and whose front end is partially closed by the annular shoulder
or ring J left within the cylinder A. The extreine forward end of the cylinder A
is in the present instance bored out to the same diameter as the piston chamber,
and has driven into it, so as to be held in fixed position therein, a chisol sleeve or
bushing K. The rounded rear end of the shank of the chisel or other working
tool L extends through the sleeve or bushing K, and in the present instance
through the ring J to a point about flush with the rear face of the latter.
The piston M consists of a solid cylindrical piece of steel fitting the bore.
within the cylinder A, and in the present instance provided with a circum-
ferential groove M near its rear end, and also having formed upon its front
end (for a purpose hereafter explained) a short projecting stem N which con-
tacts with the rear end of the shank of the tool L when the piston reaches the
forward end of its stroke.
The valve O, Figure 5, consists of a very thin steel shell, which is circular in.
cross-section at all points in its length, but of irregular shape in longitudinal section,
and the passage through which is at its sinallest diameter somewhat larger than the
piston M. Near its left hand or forward end the valve O is provided upon its exterior
with a circunferential groove a, while immediately at the right or rear of its middle
line it is formed into an outwardly projecting hollow flange or ring b whose left hand
or forward face forms an annular pressure area c against which the motive fluid acts
to move the valve rearward or to the right in the manner herenfror hereafter explained.
Near its right hand or rear end the valve is formed with an annular shoulder or
pressure area d, against which the motive fluid acts to force the valve forward, as
hereafter explained.
The valve O fits within the valve block I, which latter is composed of two parts,
a main portion or body I, und a flanged ring or disk I fitting against the rear face
of the block I. The left hand or forward half of the block I is bored out to a given
diameter corresponding to the external diameter of the left hand or forward half of
the valve O, while the right hand rear half of the block I is bored out to a larger
diameter, corresponding to the external diameter of the projecting ring b of the valve.
A circular flange or ring I projecting from the left hand forward face of the ring I
enters and snugly fits within the rear end of this larger bore of the block I, leaving
a space between the forward side of said flange and the annular shoulder at the
forward end of the larger bore of the block I, within which space the projecting ring b
of the valve fits and travels back and forth as the valve is moved in one direction
or the other. The surface f of the valve, between the ring band the pressure area d,
Figure 3, snugly fits within the flange I" of the ring I', Figures 3 and 4, while the
surface g at the rear end of the valve snugly fits within the circular opening in the
ring I when the valve is in right hand rearward position, as in Figures 1 and 4...
When the valve is in rearward position, Figures 1 and 4, there is an annular space
or chamber e between the pressure area c of the valve and the front wall or shoulder
of the larger bore of the valve block, while there is an annular chamber or space e¹
between the pressure area d of the valve and the front side of the inner edge of the
ring I The former may be called, for convenience of description, the space or
chamber in front of the valve, and the latter the space in rear of the same. When
the motive fluid is admitted to the space e¹ it will act upon the area d of the valve
and will force the latter forward if there is no motive fluid in the space e acting upon
the larger area d of the valve. When the motive fluid is admitted to the space
the pressure against the front of the valve will overcome that against the rear, and
force the valve rearward.
The larger bore of the block 1 is provided about midway of its length with an
internal circumferential groove A which communicates by a series of radial ports i
with an annular open space j around the valve block immediately in rear of the
right hand rear end of the coupling sleeee sleeve C, Figures 1 and 2, and this space j
opens to the outer atmosphere through a series of holes k in the lower side of the
threaded cap D which screws over the coupling sleeve C. The groove is therefore
an exhaust passage constantly open to the atmosphere. The ring b is provided with

page_text: a series of slots which when the valve is in right hand rear position register with
the groove h and thereby place the interior of the valve in communication with the
exhaust. When the valve is moved forward (to the left) the slots I are carried away
from the groove & and the communication between the interior of the valve and the
exhaust cut off.
The smaller bore of the valve block I is provided with two internal circumferential
grooves m n, for a purpose hereafter explained, the groove m being considerably
deeper than the groove n. When the valve is in forward left hand position these
two grooves are put into communication with each other by the circumferential
groove a upon the exterior of the valve. The rear groove n communicates by a
passage o with the exhaust port i, so that said groove is always open to the exhaust,
and when it is placed in communication with the groove m by the groove a of the
valve the groove m will then likewise be open to the exhaust. For the purpose of
furnishing freer communication between the groove n and the exhaust there are
preferably several passages o connecting said groove with different ports i.
A passage opening into the piston chainber at P, Figures 1 and 2, leads rearward
through the wall of the cylinder and through the wall of the valve block I and opens
into the annular space e in front of the pressure area c of the valve, Figures 4 and 5.
A second passage opening into the piston chamber at Q leads rearward through the
wall of the cylinder and wall of the valve block I and opens by a radial port into
the groove n in the valve block, as indicated by the dotted lines in Figures 4 and 5.
Inasinuch as the groove n is constantly open to the exhaust it will be seen that the
passage constantly communicates with the exhaust and will open the front end
of the piston chamber to the exhaust whenever the front end of said passage is
uncovered by the piston, as in Figure 2. The provision of a separate passage Q
leading back to the exhaust at the rear end of the tool is not essential, since there
might be instead simply a radial exhaust port extending through the wall of the
cylinder at the point now occupied by the front end of either the passage Qor the
passago P, and the passage Q be thus dispensed with. It is preferable, however,
to carry the exhaust back to the rear of the tool, and hence the provision of the
passage in the present instance.
A third passage R opens into the piston chamber near the front end of the latter,
and leads thence rearward through the wall of the cylinder and into the wall of
the valve block I and communicates with the groove m in the valve block. The
rear end of this passage R also communicates by a small passage S with the
space e in front of the pressure area c of the valve, as indicated by the dotted lines
in Figures 1, 2, 3, and 4.
A passage T opening into the piston chamber at a point in front of the rear end
of the piston when the latter is in forward position, Figure 1. leads thence rear-
ward through the wall of the cylinder and communicates with a small passage
extending through the wall of the valve block I and also opening into the space e
in front of the valve.
The supply inlet G which extends through the handle F of the tool opens at its
forward end into a circular groove V formed in the forward face of the head E
Communicating at its rear end with this groove V is a passage T extending for-
ward through the valve block II and the wall of the cylinder A, and opening
into the piston chamber at about the same point in its longth as the passage T,
(see dotted lines in Figures 1, 4, and 5, and full lines in Figure 6, in which latter
the front end of the passage is shown). Inasmuch as the groove V in the head E
is constantly filled with the motive fluid from the inlet G, the passage "T" will like-
wise be constantly filled with it, and when the piston M is in forward position its
grooves M will put the forward end of the passage T¹ into ciommunication with
the passage T, as in Figure 1, and the motive fluid be thereby admitted through.
the passages T U to the space e in front of the valve, as hereafter explained.
Registering with the groove V in the head E is a circular row of holes W bored
into the flanged ring of the valve block, Figure 6, in such position that their
inner sides cut through the inner surface of the flange I of said ring, Figures 1, 2, 4,

page_text: and 5, and thereby furnish comminunication between the groove V in the circular
head E and the space el at the rear of the annular shoulder or pressure area d of
the valve, with the result that the motive fluid admitted through the inlet Gin
the handle to the annular groove V in the heat E may pass through the holes W
and constantly act upon the pressure area d of the valve and tend to force the
latter forward.
One or more of the holes W communicates by a passage X with the larger
bore of the valve block I, said passage opening into the space e in front of the
valve when the latter is in rearward position, as in Figures 1 and 4, and being
closed by the ring b of the valve when the latter is in forward position, as in
Figures 2 and 5. The capacity of the passage X is greater than that of the pas-
sage S, (or, preferably, to the same end, there are several small passagos X con-
necting the space e in front of the valve with different ones of the holes W, instead
of a single large passage,) so that motive fluid may be admitted to the space e by
the passage or passages X faster than it can escape through the passage, for a
purpose hereafter explained.
Under the construction and arrangement above described the operation of the
tool is as follows; starting with the piston and valve in the position shown in
Figures 1 and 4: In such position of the parts the motive fluid admitted through
the inlet G to the annular groove V in the cylinder head E will pass through the
holes W into the space e! and act upon the pressure area d of the valve and tend
to force the latter forward, but the motive fluid in the space e in front of the
pressure area c of the valve, (admitted thereto in the manner hereafter explained).
acting upon such larger area, will serve to hold the valve in rearward position
against the pressure exerted on the area d. From the annular space e in front
of the valve the motivo fluid will pass through the passage S into the passage R, and
through the latter to the front end of the piston chainber, where it will act upon the
front end of the piston and drive the latter rearward, the rear end of the piston cham-
ber being at such time open to the exhaust through the slots / in the valve and the ex-
haust groove h in the valve block I, the groove / as before explained being constantly.
open to the outer air through the holes i, annular space j and holes k. When
the piston has moved rearward far enough to uncover the front end of the exhaust
passage the motive fluid in the front end of the piston chamber will escapo
through such passage and the groove n and its connections, heretofore explained;
to the outer air. The front end of the passage P will be uncovered at the same
time as the passage Q and the motive fluid in the space e in front of the valve will
escape through the passage P into the piston chainber, and thence through
the exhaust passage Q and its connections to the outer air. The exhaust-pas-
sage P leading from the space in front of the valve being much larger than the
passage (or passages) X by which the motive fluid is supplied to such space the
pressure upon the area c of the valve will be greatly diminished when the front
end of the exhaust passage P is uncovered by the piston, so that the pressure of
the motive fluid in rear of the valve, which is acting constantly upon its smaller
pressure area d, will force the valve forward to the position shown in Figures 2
and 5, whereupon the projecting ring 6 of the valve will close the front end of the
passage X and cut off the supply of motive fluid from the space in front of the
valve, thereby permitting the pressure upon the smaller area d of the valve to
hold the latter in forward position. When the valve is thus moved to forward
position its extreme rear end will have been carried forward beyond the circular
inner edge of the ring I of the valve block, leaving an annular opening p entirely
around the rear end of the valve, between the latter and the inner edge of the
ring 11, (Figures 2 and 5), through which opening the motive fluid may pass from
the holes W and annular space e to the interior of the valve, and there acting upon
the rear end of the piston drive the latter forward again. As the piston moves
forward the air in front of it can escape through the exhaust passage Quntil the
latter is closed by the front end of the piston, and thereafter can escape through
the passage R into the groove m in the valve chamber, which groove, when the

page_text: valve is in the position it occupies while the piston is moving forward, is in com-
munication with the exhaust groove n through the medium of the groove a in the
exterior surface of the valve, so that the air driven backward through the pas-
sage R may escape to the outer air. When the piston has moved forward far
enough for its groove M¹ to place the front end of the live air passage T¹ in com
munication with the passage T the motive fluid from the passage T' will pass
through the passages T and U to the space in front of the pressure area c of the
valve, Figures 2 and 4, and there acting upon the said area of the valve will over-
come the constant pressure which is acting upon the smaller area d of the valve
and force the valve rearward again. This rearward movement of the valve will
open the front end of the passage X and again admit motive fluid through the
latter to the space e in front of the valve, and will also open the passage S leading
from such space to the passage R and front end of the piston chamber. It will
also open the interior of the valve to the exhaust, through the slots and exhaust
groove A, so that the pressure behind the piston may escape, and will cut off the
exhaust from the passage R and front end of the piston chamber by disconnecting
the grooves m and n, so that the motive fluid admitted to the front end of said
chamber through the passages S and R will drive the piston rearward again.
rearward movement of the piston will carry its groove M away from the front ends
of the passages T and T and close the cominunication between them, and the
admission of motive fluid from the live air passage T¹ to the space e in front
of the valve be thereby cut off; but the motive fluid admitted to such space
through the passage (or passages) X will serve to hold the valve in rearward
position, notwithstanding the escape of motive fluid through the passage S,
since the latter is of sufficiently less capacity than the passage or passages X
for that purpose.
The
It will be understood that while the passage T' is put into communication with
the passago T by the groove M, to shift the valve, before the front end of the
piston strikes the shank of the tool L, the momentum of the piston and the ex-
panding pressure behind it carries it on forward into contact with the tool; and
that, likewise, while the exhaust passage Q is uncovered by the front end of the
piston before the latter has reached its rearward limit of stroke, the momentum of
the piston and the expanding pressure behind it will carry it on rearward, the
motive fluid admitted in rear of it by the shifting of the valve before it completes
its rearward stroke serving to cushion it at the end of such stroke. The desideratum
is to so adjust and time the operation of the parts that the piston shall be moved
rearward as far as may be possibly done without danger of its rear end hammering
against the cylinder head, in order that as long a forward stroke as possible may be
obtained. The parts may be so adjusted that the piston will move at its rearward
stroke to or beyond the position shown in Figure 2, and there be cushioned by the
newly admitted motive fluid and not allowed to strike the cylinder head E.
The live air passage T¹ and the groove M¹ in the piston may be dispensed with
by opening the front end of the passage T into the piston chamber at a point
slightly in rear of the rear end of the piston when the latter is in its forward
position, as shown in Figure 10, instead of having it open into the piston chamber
at the point shown in Figures 1 and 2. Under such arrangement of the passage T
(and dispensing with the passage T and groove M' in the piston,) when the piston
approached its forward limit of stroke and its rear end uncovered the front end of
the passage T the live air in rear of the piston chainber would pass through the
passages T and U, to the space e at the front of the valve, and there acting upon its
pressure area c force it rearward, just as does the live air adınitted from the
passage T through the passages TU in the construction illustrated in Figures 1 and 2.
The passage U is of such limited size that its capacity combined with that of the
passage S is less than the capacity of the passage or passages X, so that the inotive
fluid would be admitted by the latter to the front side of the valve faster than it
could escape through the passages U and S, (after the rearward movement of the
valve opened the rear end of the piston chamber to the exhaust) and serve to hold

page_text: the valve in rearward position notwithstanding the escape of motiva fluid through
the passages U and S. As soon as the piston began to move rearward the front
end of the passage T (Figure 10) would be closed by the piston, so that there could
then be no further escape of motive fluid through the passage U., In tools of some
sizes, and under some conditions, however, I have found the valve to operate better
when moved rearward by live air admitted to its front side directly from the source
of supply, as distinguished from that admitted to it from the piston chamber under
the modification shown in Figure 10, and I have therefore illustrated and described
my preferred construction as embodying the live air passago T and groove M' in
the piston, as in Figures 1 and 2, although the arrangement explained in con-
nection with Figure 10 is entirely satisfactory in many tools, and is clearly within
the broader scope of my invention.
Under the preferred construction shown in Figures 1 and 2 it is not essential
that the passage U shall be made of such limited capacity as has been described,
but under the construction in Figure 10 it is necessary that it shall have such
limited.capacity, or else that a check-valve be interposed in it to prevent the escape
of motive fluid from the space e in front of the valve when the rear end of the piston
chamber is opened to the exhaust.
From the foregoing description of my new tool it will be seen that inasmuch as
the rear end of the piston chamber extends entirely through the valve block and
valve the space occupied by the latter is not provided at the expense of the piston
chamber, and that said chamber is as long as it could be made even if the
valve were arranged in a chamber at one side of and parallel to the piston
chamber, instead of in line and concentric therewith. In the tool from which the
drawings were made the longitudinal thickness of the valve block is about an
inch and a quarter, (as will appear from the full-sized views of said block in
Figures 4 and 5,) and in tools of the same size made in accordance with my pre-
viously mentioned patent the valve blocks were of approximately the same
longitudinal thickness. In such prior tools the piston chamber necessarily termi-
nated at the forward side of the valve block, while in my present tool it extends
entirely through the valve block, so that in a tool of given length as a whole the
piston chamber under the construction of my present tool may be made more than
an inch longer than under the construction employed in my prior tool, with
the consequent possibility of correspondingly increasing the length of the piston
and the power of action of the tool.
Inasinuch as the valve in my new tool consists of an exceedingly thin steel shell,
and is consequently very light, and inasmuch as its limit of movement is very short,
not exceeding an eighth of an inch in a tool of the size from which the drawings
were inade, (Figures 4 and 5) it follows that the momentum acquired by the valve.
in its rapid reciprocations is vory slight, and is not sufficient to so hammer the
valve against the abutments at the opposite ends of its strokes as to cause damago
and rapid wear of the valve.
Under the construction shown in Figures 1 and 2, (which includes the live air
passage T and the groove M' in the piston) the auxiliary passage X is necessary
only for the purpose of supplying motive fluid to the front end of the piston
chamber, through the passage S, and in event some other passage controlled by the
valve for supplying the motive fluid to the froat end of the piston chamber were
substituted for the passage S, as might be done, the auxiliary passage would be
unnecessary. Under the construction shown in Figure 10, however, the auxiliary
passage X is necessary for the further purpose of supplying motive fluid to the
larger area of the valve, to hold the latter in rearward position alter it has been
moved thereto by the motive fluid admitted to it from the piston chamber through
the passage T U. As will be understood, the rearward movement of the valve opens
the rear end of the piston chamber to the exhaust and the motive fluid which had
been admitted to the larger area of the valve through the passage. T U in Figure 10
would escape backward through said passage and perinit the pressure behind the
valve to force it forward again if it were not for the provision of the auxiliary

page_text: passage X for supplying motive fluid to the larger area of the valve faster than it
can escape therefrom. Under the construction shown in Figure 10, therefore, the
provision of the auxiliary passage X, and the reduction in size of the portion U of
the passage leading to the piston chamber, enable me to dispense with the check
valve which in the machine of my prior patent was employed in the passage leading
from the piston chamber to the larger area of the valve, and the auxiliary passage X
thus serves a useful purpose in the construction shown in Figure 10 quite inde-
pendently of its function of supplying motive fluid to the passage S leading to the
front end of the piston chamber.
From the foregoing it will be understood that while the auxiliary passage serves
the purpose in the construction of Figures 1 and 2 of supplying motive fluid to
the front end of the piston chamber, and while in the construction of Figure 10 it
serves that purpose and also the further purpose of rendering unnecessary any
check valve in the passage leading from the piston chamber to the larger area of the
valve, it nevertheless is not absolutely essential to either construction, and may be
'dispensed with in the former hy substituting some other passage for the passage S,
as heretofore explained, and in the latter by making the same substitution and by
placing a check valve in the passage between the piston chamber and larger area of
the valve, as in my prior machine. So far as I am aware, however, the valve
mechanism of my new tool is the first instance in which an auxiliary passage
such as the passage X, co-operating with the valve in the manner described, has
been employed for either of the purposes mentioned. It therefore forms a novel
and useful, even though not absolutely essential, feature of my new valve mechanisın,
and may also be employed in connection with valves of other form than that herein
shown and described, such, for instance, as the valve of my prior patent.
The purpose of the stem N projecting from the front end of the piston M is to
provide a cushion for the piston at the end of its forward stroke, and prevent its
striking the shoulder J at the front end of the piston chamber, whenever the chisel
or other working tool L is not in position to receive the blows of the piston and
arrest the latter. At such time the stem N will enter and snugly fit the opening
within the annular shoulder or ring J, and as the front end of the passage R will be
closed by the front end of the piston proper at about the same time the air between
the end of the passage R and the shoulder J will be trapped and serve to arrest and
cushion the piston, and prevent its striking the shoulder J. So long as the chisel L
is in working position, however, the stem N is not necessary for this purpose, since
the contact of the piston with the end of the shank of the chisel will serve to arrest
the piston. If, therefore, means were provided for holding the working tool in
position, (as is frequently done in tools of this character) the piston need not be
provided with the stem Ñ, but its front end be left the same as its rear end, the
shank of the tool L in such case being arranged to project slightly into the front
end of the piston chamber, to receive the blows of the piston, and the passage R
being made to open into the piston chamber nearer the front end of the latter. In
such event the piston would be permitted a still longer stroke than in the present
instance.
It will be noticed that the shank of the chisel L, by closing the opening, which
leads into the front end of the piston chamber, itself forms a part of the end wall of
said chamber or the abutment against which the motive fluid admitted by the
passage R acts in driving the piston rearward. So far as I am aware I am the first
in the art to employ the shank of the chisel or working tool for this purpose, or to
'so construct and arrange the parts that it could be employed for this purpose. By
so employing it the variety of means heretofore used for closing the front end of
the piston chamber are entirely dispensed with, and the construction of the tool
simplified and cheapened. I have found from experiments and practical use of
tools of this character that the rebound of the piston from contact with the working
tool is of itself nearly sufficient to return the piston to the rear end of the piston
chamber,so that but a small quantity of motive fluid need be admitted to the front end
of the piston chamber for this purpose, and that the front end of the piston chamber

page_text: need not be air-tight in order that the motive fluid may act with sufficient force.
To such an extent is this true that no great care need be exercised in having the
shank of the chisel snugly fit the chisel sleeve K or the opening within the ring J
and I have found the tool to work satisfactorily in some instances with a chisel
whose shank was not round, but hexagonal in shape, the round shoulder of the
shank, which fits against the outer end of the chisel sleeve, serving to sufficiently
confine the motive fluid in the front end of the piston chamber.
One of the chief objections to the use of tools of this character has heretofore been
the shock and jar incident to their use, which caused a severe strain upon the
workınan using them. These shocks and jars were caused to an equal or greater
extent by the rearward strokes of the piston, than by the forward strokes thereof.
As before stated, I have discovered that the rebound of the piston from contact
with the working tool is of itself nearly sufficient to return the piston, so that in
my new tool I have arranged to admit motive fluid to the front end of the piston
chamber through a very small passage (S), and to cut off its admission thereto and
open the exhaust before the piston has nearly reached its rearward limit of stroke,
with the result that the rebound of the piston from contact with the working tool
is aided by a very small quantity of motive fluid admitted in front of the piston
during only a portion of its rearward stroke, so that while the piston is thrown
rearward quickly enough, it is not moved with sufficient force to cause the
objectionable jarring of the tool heretofore referred to.
The novel locking device for preventing the coupling sleeve from unserowing,
which has been heretofore referred to, is illustrated in Figures 7, 8, and 9, where
Figure 7 is a sectional detail in a vertical plane immediately in front of the front
end of the coupling sleeve, and looking toward the rear. As there shown it will be
seen that the inner edge of the internal flange upon the front end of the coupling
sleeve is serrated to co-operate with a locking block Y which is seated in a radia
bore in the wall of the cylinder A, and is pressed upward by a coiled spring Z
placed beneath it and fitting in a recess in its under side. The upper or outer end
of the locking block Y has formed upon it one or more teeth a' to co-operate with
the serrations of the coupling sleeve, the spring Z serving to normally engage said
teeth with said serrations and thereby prevent the coupling sleeve being turned
backward. The locking block Y is held in place in the bore in which it fits by a
pin b which is driven from the rear end of the cylinder through a longitudinal
hole intersecting the recess in which the block Y fits, which pin overlies a
shoulder c' upon the side of the block Y, and prevents the latter being forced out
of place by the spring Z when the coupling sleeve is removed and the tool taken
apart. The locking block Y is provided with a second shoulder, d', located above
and at an angle to the shoulder c', and when it is desired to release the coupling
sleeve from the locking device, to permit it to be unscrewed and the tool taken.
apart, it is only necessary to press the locking block Y downward slightly, against.
the resistance of the spring Z, and then turn it in the direction of the arrows in
Figures 8 and 9, to move its shoulder d beneath the pin 6, whereupon, u on
removing pressure from the block Y, the engagement of the shoulder d with the
pin 6 will prevent the spring Z forcing the block upward into re-engagement with
the serrations of the coupling sleeve. When the parts of the tool are again
reassembled, and the coupling sleeve screwed tightly in place, the locking block Y
can be re-engaged with the serrations of its flange by simply turning it back to
normal position, to disengage its shoulder d' from the pin band permit the spring
Z to press it upward again.
In the tools of my prior patent I employed a coupling sleeve having the inner
edge of its flange serrated as in the present instance, and a locking device located
in the wall of the cylinder and co-operating with the serrations of the coupling
sleeve to prevent the latter becoming unscrewed; but the locking device above
described is simpler and better than the ones heretofore employed, and much more
convenient in operation by reason of the ease with which it may be disengaged
from the serrations of the coupling sleeve and maintained out of engagement there
with while the sleeve is unsorowod and removed and replaced in position.

page_text: Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1-In-a-pneumatic-hammer;-a-valve-for-controlling-the-movemente-of-the-piston
eonsisting-of-a-eylindrical-shell-located-in-the-piste --chamber-and-adapted-to-have
the-piston-pass-through-it,-and-provided-with-opposing pressure-areas-against-which
the-motive-fluid-acts-to-shift-the-valve-in-opposite-directions.
1. In a hand pneumatic hammer, a valve for controlling the movements of
the piston, consisting of a cylindrical shell located in the piston chamber and
adapted to have the piston pass through it, and provided with opposing pressure
surfaces of different areas, against the smaller of which the motive Buid constantly
acts, to press the valve in one direction, and to the larger of which the motive
fluid is intermittently admitted, to move the valve in the opposite direction, sub-
stantially as described.
2-3. In-a-pneumatie hammer,-the--combination, with--the--piston-chamber-and
piston, of-a-valve-located-in-the-piston-ebamber-and-consisting-of-a-cylindrical-shell
through-which-the-piston-passes,-and--provided--with--differential--pressure--areas
against-the-smaller--of-which-the-motive-fluid-constantly asts--to-press- he-valve in
ene-direction;-and-a-passage-controlled-by-the--pis: on--for--intermittently admitting
the-motive-fluid to--the--larger--pressure--area--to--move-the-valve-in-the--opposite
direction.
3-4. In-a-pneumatie-hammer,-the--combination,--with-the-piston chamber-and
piston,-of-a-valve-located-in-the-rear-end-of-the--piston--chamber--and--consisting-of-a
eylindrical-shell-through-which-the--rear--end--e--the--piston-passes-at- the--end-of-its
rearward stroke, and provided-with-differential--pressare-areas-against-the--smaller
of-which-the-motive-fluid-constantly-asts-to-press-the--valve-in--oue-direction,-and-a
passage-controlled-by-the-piston-and--opened-by-the--latter--at-is-forward-stroke-to
admit-motive-fluid-to-the-larger-area-of-the-valver
4-5.-In-a-pneumatie-hammer;-the-combination;-with--the--piston chamber-and
piston;-of-a-valve-loeated-in-the-rear-end-of-the--piston-ehamber-and-eons sting-of-a
eylindrical-shell-through-which-the-rear-end--of--the--piston--passes-at-the-end-of-its
rearward-stroke,-and-provided-with-differential-pressure--areas-against-the--smaller
of-which-the-motive-fluid-constantly-aets-to-press-the--valve-forward;-and-a-tassage
controlled-by-the-piston-and-opened-by-the-latter--at-its--forward-stroke-to-admit
motive-fluid-te-the-larger-area-of-the-valve,-to-move-the-valve-rearward.
2.5.-6. In a hand pneumatic hammer, the combination, with the piston chamber
and piston, of a valve located in the rear end of the piston chamber and consisting
of a cylindrical shell through which the rear end of the piston passes at the end of
its rearward stroke, and provided with differential pressure areas against the
smaller of which the motive fluid constantly acts to press the valve forward, and
a passage controlled by the piston and opened by the latter at its forward stroke to
admit motive fluid to the larger area of the valve, to move the valve rearward, said
valve when moved forward by the constantly acting pressure against the smaller
area opening an annular port around its rear end to admit the motive fluid to the
rear end of the piston chamber, and when moved in the opposite direction by the
intermittent pressure admitted to its larger area opening a passage leading to
the front end of the piston chamber, substantially as described.
6-7. In-a-pneumatic--hammer,-the--combination;-with-he-piston-chamber-and
piston,-of-a-valve-for-controlling-the-movements-of-the-piston,-consisting-of-a-erlin-
drical-shell-loeated-in--the-piston--chamber--and--adapted-to--have--the-piston-pass
through-it,-and-provided-with-differential--pressure--areas -against--the--smiller--of
which-the-motive-fluid-constantly aste-to--press-the-valv. -in-one-direction,-a-passage
controlled by the-piston-and-opened-by--the-latter-at--its--forward--stroke-to-admit,
motive-fluid-to-the-larger-area-of-the valve; and an exhaust-passage-leading-from-said
larger-area-of-the-valve-and-opened-by-the-piston-at-its-rearward-stroke.
78-In-a-pneumatie-hammer;-the--combination, with--the-piston-chamber-and
piston,-of-a-valve-provided with differential--pressure--areas--against-the-smaller-of

page_text: whieh-the-motive fluid-constantly-nets-to-press-the-valve-in-one-direction,- a-passage
controlled-by-the-piston-for-intermittently-admitting-the-motive-fluid-to-the--larger
area of-the-valve,-to-move-the-valve-in-the-opposite-directions-and--an-auxiliary-pas-
sage-opened-by-the-last-mentioned--mevement-of-the-valve-to-admit--an-additional
supply-of-motive-fluid-to-the-larger-area-of-the-valve.
80. In-a-pueumatie-hammer,-the-eombination;-with--the-piston--chamber-and
piston,-of-a-valve-having--differential--pressure--areas--against-the--smaller-of-which
the-motive-fluid-constantly-aets-to-press-the--valve-in--one--direction,-a-passage-con-
trolled-by-the-piston-and-opened-by-the-latter--at-its--forward-stroke,-to--admit
motive-fluid-to-the-larger-area-of-the-valve--and--move--the--letter--in--the--opposite
direction,-an-auxiliary-passage--opened--by-the--last--mentioned--movement--of-the
valve-te-admit-motive-fluid-to the-larger-area-of-the-valve--direetly-from-the-soures
of-supply-and-an exhaust-passage-leading from-said--larger-area--et--the--valve-and
area-than-the-auxiliary-passage-by-which-the-motive--flaid-is-admit ed-ta-the-larger
opened-by-the-piston-at-its-rearward-stroke,-said--exhaust-passage--being-of-larger
area-of-the-valve.
0.-10. In-a-pneumatie hammer-the-combination,-with--the-piston-chamber-and
piston, of-a-valve-having--differential--pressure--areas--against-the-smaller--of-which
the-motive-fluid-constantly acts--to--press-:he-valve in-one-direction,-a--passage-een-
trolled-by-th--pis:
on--and-opened-by--the--latter--at-its--forward--stroke,-to--admit
motive-fluid to-caid-larger--area--of-the-valve-and--move--the-latter-in-the--opposite
direction, and-an-auxiliary-passage-opened-by-the-last-mentioned--movement-of-the
valve-to-admit-motive-flaid-to-the-larger--area-of-the-valve-directly-from-the-souree
of supply, said auxiliary-passage-exseeding-in--eapacity--the-said--passage-controlled
by-the-piston.
10-11. In-a-pneumatic-hammer,-the-ecmbination,--with-the-pisten-chamber-and
piston;-of-a-valve-having-differential--pressure--aras--against-the--smaller-of--which
the-motive-fluid-constantly-acts-to-press-the-valve-in-one-direction,-a-passage-con-
trolled by the-piston-for--intermittently--admitting-motive-fluid-to-the--larger- rea
of-the-valve--to-move-the-latter-in-the--opposite-direction, an--auxiliary passage
larger-area-of-the-valve-directly-from-the--souree-of- supply,--and--a-passage-leading
opened-by-the-last-mentioned--mevement-of-the-valve-to-admit-motive-fluid-to-the
from-the-larger--area-of-the-valve-to-one-end-of-the-piston-chamber--through-which
the--motive-fluid-admitted-by-the-auxiliary-passage--may-pass-to--said--end-of-the
piston-chamber-and-drive-the-piston-toward-the-opposite-end-of-the-chamber.
11-12 In-a-pneumatie-hammer,-the-combination;-with-the-piston-ehamber-and
piston,-of-a-valve-having-differential--pressure--areas--against-the-smaller-of-which
the-piston-and-opened-by--the--latter--at-its-forward-stroke,-to--admit-motive-fluid
sage--opened--by-the-last-mentioned-movement--of-the--valve-to-admit-motive-fluid
to the-larger-area-of-the-valve--direetly-from-the--souree-of--supply-and-a-passage
leading from--such-larger-area--of--the--valve-to-the--front-end-of-the-piston-cham-
ber,-through-which-the--motive--flaid--supplied-by--the--auxiliary--passage-may-be
admitted-te-the-front-end-of-the-piston-chamber-to-drive-the-piston-rearward.
3. 12. 13. In a hand pneumatic hammer, the combination, with the piston
chamber and piston, of a valve having differential pressure areas against the
smaller of which the motive fluid constantly acts to press the valve in one direction,
a passage controlled by the piston and opened by the latter at its forward stroke,
to admit motive fluid to the larger area of the valve and move the latter in the
opposite direction, an auxiliary passage opened by the last mentioned movement of
the valve to admit motive fluid to the larger area of the valve directly from the
source of supply, and a passage leading from such larger area of the valve to the
front end of the piston chamber, through which the motive fluid supplied by the
auxiliary passage inay be admitted to the front end of the piston chamber to drive
the piston rearward, the capacity of the aforesaid auxiliary passage being greater
than the combined capacity of the other two passages communicating with the
larger area of the valve, substantially as described.
the-motive-fluid-constantly-aets-to-press-the--valve-forward, -a-passage-controlled-by
to-the-larger-area of the valve--and--more--the--latter--rearward;-an-auxiliary-pas-

page_text: 4 13 11. In a hand. pneumatic hammer, the combination with the piston.
chamber and. piston, of a valve having differential pressure areas against the
smaller of which the motive fluid constantly acts to press the valve in one direction,
a live air passage leading directly from the source of supply to the piston chamber,
through the wall of the latter and independently of the piston and a passage leading
from the piston chamber to the larger area of the valve, the piston operating to
close plaee-said-passages-in communication between said passages except when with
each-other-as it approaches one end of its stroke, and then place said passages in
communication with each other to thereby admit the motive fluid to the larger area
of the valve, substantially as described. and--operating--to-close-communicatio i
between-said-passages-as-it moves-in-the-opposite-direction.
5. 14. 14a. In a hand pneumatic hammer, the combination, with the piston
chamber and piston, of a valve having differential pressure areas against the smaller
of which-the motive fluid constantly. acts to press the valve in one direction, a live
air passage leading directly from the source of supply to the piston chamber, and
a passage leading from the piston chamber to the larger area of the valve, the
piston being provided with a circumferential groove which places said passages
in communication with each other as the piston approaches its forward limit of
stroke; to thereby admit the motive fluid to the larger area of the valve, and
the piston operating at its rearward stroke to cut off such communication and to
open an exhaust passage from the larger area of the valve., substantially as
described.
15. In--a-pneumatie-hammer,-the-combination,-with-the-piston-chamber-and
piston, of a valve-having-opposing--pressure-areas--to--which--the-motive--fluid--is
admitted-for-shifting-the-valve-in-opposite--directions,--a-passage-controlled--by-the
piston-for-intermittently-admitting-motive-fluid-to-one--of-the-pressure-areas-of-the
valve,-to-move-the-letter-in-one-direction,-and--an-auxiliary-passage-opened-by-the
last-mentioned--movement-of-the-valve-to-admit an-additional-supply-of-motive-fluid
to-said-larger-area-of-the-valver
16-In-a-pneumatie-hammer, the-combination,-with-the-piston-chamber-and-pis
ton, of a valve having-opposing-pressure-areas-to--which-the-motive-fluid-is-admitted
tor-shifting-the-valve-in-opposite-directions, a--passage--controlled-by-the-piston, for
intermittently-admitting-motive-fluid-to-one-of-the--pressure--areas-of-the-valve, to
move-the-latter-in-one-direction,-an-auxiliary-passage-opened by-the-last mentioned
movement-of-the-valve-to-admit-an-additional-supply-of-motive-flaid--to-said-area-of
the valve,-and-a-passage-leading-from-said-area-of-the-valve-to-one-end-of-the-piston -
ehamber, through-which-motive--fluid-supplied-by--the--auxiliary-passage may be
admitted-to-said-end-of-the-piston-chamber-to-move-the-piston-toward-the-opposite
end-of-said-ehamber.
17. In-a-pneumatic-hammer,-the-combination,-with-the-piston-ehamber-and-pic-
ton,-of-a-valve-located-in-the-piston chamber-and--consisting of -a-eylindrical-shell
through--which--the-pisten--passes, and--provided--with--differential-pressure-areas
against-the-smaller-of-which-the-motive-fluid-eonstantly--aets-to-press-the-valve-in
one-direction,-a-passage-controlled-by-the-piston-for-intermittently-admitting-motive.
fluid-to-the-larger--pressure area of-the-valve,--te--move-the--latter--in--the--opposite
direction, and--an-anxiliary-passage-opened-by-the-last-mentioned--movement-of-the
valve-to-admit an-additional supply-of-motive-tuid to-the-larger-area-of-the-valver
18-Ina--pneumatie--hammer, the combination,--with--the--piston--chamber-and
piston,-of-a-valve-for-controlling-the-movements-of-the-piston,-consisting-of-a eylin-
drical-shell-loeated-in-the-rear-end of-the-piston-chamber-and-adapted--to--have--the
rear-end-of the-piston-pass-through-it-at-the-end-e-its-rearward-stroke-and-provided
with--differential-pressure-areas-against-the-smaller-of-which-the-motive-fluid-con-
stantly--aets-to-press-the-valve-in-one-direction,-a-passage-controlled--by-the-piston
and-opened by the latter--at-its-forward-stroke, to-adm.t-motive-fluid-to-the-larger
area of the valve--and--move-the--latter-in-the-opposite-dir.etion,-and-an-auxiliary
passage--opened--by-the-last-mentioned-movement--of-the--valve--to--admit-motive
fluid to the-larger-area-of-the--valve--direetly-from-the--source-of--supply.
10. In-a-pneumatie -hammer,-the-combination,-with-the--piston-chamber-and
piston,-of-a-valve-located-in-the piston-chamber-and consisting-of-a-cylindrical-she!!

page_text: through-which--the-piston--passes--and--provided--with--differential--pressure--areas
against-the--smaller-of-which-the-motive-fluid-constantly-aets-to-press-the--val-
one-direction, a-passage-controlled-by-the-piston-and--op:ned-by-the-la ter-at-its-for
ward-stroke-to-admit-motive-fluid-to-the-larger area of the valve-and-move-the lat ee
in-the-opposite-direction,-an-auxiliary-passage-opened-by-the-last-mentioned--move
ment--of-the-valve-to-admit-motive-fluid-to-the-larger-area--of--the-valve:dirtet!
from-the-souree--of-supply,--and--an-exhaust--passage--leading--from--said-larger
area-of-the-valve-and-opened-by-the-piston-at-its-rearward-stroke,-said-exhaust-pas-
sage-being of larger-area-than-the-auxiliary-passage--by whieh--the--motive--fluid--is'
admitted-to-the-larger-area-of-the-valve.
20:-In-a-pneumatie-hammer, the-combination,-with-the-piston-chamber-and-pis-
ton;-of-a-valve-for-controlling-the-movements-of the--pistos, consisting-of-a--erlin-
drical--shell--located--in--the--piston--ehamber--and-adapted-to-have-the-piston-pass
through it, and--provided--with--differential--pressure-areas--against-the-smaller-of
which-the-motive-flaid--constantly--acts--to-press-the valve-in--one--direction,-a-pas
sage-controlled-by-the-piston-and opened-by-the latt-r-at-its forward-stroke,-to-admit
motive fluid-to-said-larger-area-of-the-valve--and--move-the-latter--in-the-opposite
tion,-and-an-auxiliary passage-opened-by-the-last ment ened-movement-of-the-valve
to-admit-motive-fluid-to-the-larger-area-of--the--valve--direet!y-from-the--source-of
supply, said-auxiliary-passage-exeeeding-in-area-the-said--passage-controlled-by-the
piston.
21. In-u--pneumatic--hammer,-the--combination;-with-he--piston--chamber--and
piston,-of-a-valve-located--in--the--piston-chamber--and--cousisting-of--a--eylindri al
against-the-smaller-of-which-the-motive-fluid--constantly--acts--to-press-the-valve-in
one-direction,-a-passage controlled--by-the-piston--for--intermittently-a 'mitting-the
motive-flid-to-the-larger-area-of-the-valve-to-move-the-latter-in-the-opposite--diree-
tion,-an-auxiliary-passage opened-by-the-last-mentioned--movement--f-the-valve-te
admit-motive-fluid-to-the-larger-area-of-the-valve-directly-from-the-source-of-supply,
and-a-passage-leading-from-the-larger-area--af--the--valve--to--one-end-of-the-piston
chamber-through-which-the-motive-fluid--admitted-by--the--auxiliary--passage-may
shet-through-which-the-piston-passes,-and provided--with-differential-pressure-areas
pass-to-said end-of-the-piston chamber-and-drive-the-piston-toward-the-opposite-end
of the-chamber.
mber-and-adapted--to--have--the
22. In-a-pneumatis--hammer, the combina ion--with--the--piston--chamber-and
piston,-of-a-valve-for-controlling-the-movements-of-the-piston;-eonsisting-of-a eylin-
drical-shell located-in-the-rear-end of-the-piston-ch
rear-end-of the-piston-pass-through-it-at-the-end-of-its-rearward-stroke,-and-provided
with--differential-pressure-areas-against-the-smaller-of-which-the-motive-fluid-een-
stantly-aets-to-press-the-valve-in-one-direction,-a-passage-controlled--by-the-piston
and-opened-by-the--latter--at-its-forward--stroke,-to-admit-motive-fluid-to-the-larger
area-of-the-valve--and--more--the--latter--in--the--opposite--direction--an-auxiliary
passage--opened-by-the-last-mentioned-movement--of the--valve--to--admit-motive
Anid-to the-larger-area-of-the--valve--directly-from- the--source-of--supply,-and-a-pas-
sage-leading-from-such larger-area-of-the-valve-to-the-front-end-of-the-piston-eham-
ber-through-which-the--motive-flaid--supplied--by--the-auxiliary passage--may--be
admitted-to-the-front-end-of-the-piston-chamber-to-drive-the-piston-rearward.
23. In-a-pnenmatie-hammer-the-combination,-with-the-piston-chamber-and
piston-of-a-valve-loeated-in-the rear-end-of-the--piston-chamber-and-consisting-of-a
:
eylindrical shell-through-which-the-rear-end-of-the-piston--passes--at-the--end-ef-its
rearward-stroke, and-provided-with-differential-pressure-areas-against-the-smaller-of
which-the-motive-fluid--constantly-acts--to-press-the--valve-in-one--direction,-a-pas-
sage-controlled--by-the-piston-and-opened-by-the-latter--at--its--forward-stroke, to
émit-motive-flaid-to-the-larger-area-of-the-valve-and-move-the-letter-in-the-opposite
direction,-an-auxiliary-passage opened-by-the-last-mentioned movement--f-the-valve
to-admit-motive flaid--to-the--larger-area--of-the-valve-directly from the-source-of
supply, and-a-assage-leading-from-such-larger-area-of-the-valve-to-the-front-end-of
the-piston-chamber,-through-which-the-motive-fluid-suppl ed-by-the--auxiliary-pas

page_text: sage-may-be-admitted-to-the-front--end-of--the--piston--chamber-to-drive-the-piston.
rearward,-sneh passage-leading-to-the-front-end-of-the-piston chamber-being-of-less
capacity-than-the--aforesaid--auxiliary--passage--whereby-the--necessary---ressure,
ag inst-the-larger-area-of-the-valve-may-be--maintained-by-the-motive-fluid-admit-
ted-through-the--auxiliary--passage--notwithstanding--the--esespe--of--motive--fluid
through-the-passage-leading-to-the-front-end-of-the-piston-chamber.
24. In-a-pneumatie-hummer,-the--combination, with--the-piston-chamber-and
piston,-of-a-valve-located-in-the rear-end-of-the--piston-chamber-and-consisting-of-a
eylindrical-shell-through-which-the-rear-end-of-the--piston-passes--at-the-end-of-its
rearward-stroke,-and-provided--with--differential-pressure-areas-against-the--smaller.
trolled-by-the-piston-for-intermittently-admitting-the-motive-fluid-to-the-larger-area
of-which-the-motive-fluid-constantly-aets-to-press-the--valve-forward; a-passage-een-
ef-the-valve,-te-move-the-lutter-rearward, and-an-auxiliary-passage--opened-by-sueh
rearward-movement-of-the-valve-to-admit-an--additional--supply-of-motive--fluid-te
the-larger-area-of-the-valve.
25. In-a-pneumatie-hammer,-the-combination,--with--the--piston--ehamber--and.
piston, of a valve-located-in-the-rear-end-of-the-piston-ehamber-and--consisting-of-a
eylindrical-shell-through-which-the-rear-end-of-the--piston--passes-at--the-end-of-its
rearward-stroke,-and--provided-with-differential-pressure-areas-against-the-small.p
of-which-the-motive-fluid constantly-acts-to-press the valve-forward,-a-passage-con-
trolled-by-the-piston-and-opened by the latter-at-its-forward--stroke,-to-admit-motive
fluid-to-the-larger-area-of-the-valve,-to-move-the--valve-rearward,-an-auxiliary-pas-
sage-opened-by-such-rearward-movement-of-the-valve-to-admit-motive flaid-to-the
larger-area-of-the--valve--directly-from-the--source-of-supply,-and-an-exhaust-pas-
sage-communicating-with-the-larger-area-of-the-valve-and--open ed-by-the-piston-at
its-rearward-stroke.
26. In-a-neumatic--hammer,-the--combination,-with-the--piston-chamber-and
piston,-of-a-valve-located--in--the-rear-end-of-the-piston-chamber-and-cousisting-of-a
cylindrical shell-through-which-the-rear-end-of-the-piston--passes--at-the--end-of-its
rearward-stroke, and provided-with-differential-pressure-areas-against-the-smaller-of
which--the--motive--fluid---constantly--acts--to--press--the--valve--forward,--a-pas-
sage controlled--by-the--piston--and-opened-by-the-latter--at--its--forward-stroke, to
almit-motive-fluid-to-the-larger-area-of-the-.valve,-to-move-the-valve-rearward,--an
auxiliary-passage-opened-by-sueh-rearward--movement-of-the-valve-to-admit-motive
fluid--to-the--larger-area-of-the-valve-directly-from-the-souree-of-supply,-and-a-; as-
sage-leading-from-such-larger-area-of-the-vaive-to-the-front-end-of-the-piston-cham-
ber, through-which-the-motive-fluid-supplied-by-said- auxiliary-passage
mitted-to-the-front-end-of-said-chamber-to-drive-the-pisten-rearward.
may-be-ad-
27-In-a-pneumatie--hammer,-the combination,--with--the--piston--ehamber--and
piston-of-a-valve-located-in-the-rear-end-of-the--piston-chamber-and-eens.sting-of-a
eylindrical shell-through-which--the--rear end-of-the-piston--passes-at-the-end-of-it-
rearward-stroke, and provided-with--differential-pressure--areas-against-the-smaller
trolled--by-the-piston--and--opened by-the--latter--at-its-forward-stroke,--to--admit
of-which-the-motive-fluid-constantly-aets-to--press-the-valve-forward;-a-passage-con-
motive-fluid-to-such-larger-area-of-the-valve,--to-move--the-valve--rearward,--an
auxiliary passage--opened-by-such-rearward-movement-of-the-valve-to-admit-motive
fluid to the larger-area-of-the-valve--directly-from-the--souree-of--supply,--a-passage
leading-from-the larger-area-of-the-valve to the-front-end-of-the-piston-chamber,
through-which-the-motive--fluid--supplied-by--said-auxiliary passage-is-admitted-to
the-front-end-of-said-chamber, to-drive-the-piston-rearward,-and un-exhaust-passage
leadin-from-the-larger-area-of-the-valve-and-opened-by-the--rearward-movement-of
the-piston:
28. In-a-pneumatic-hammer, the-combination-of--a--eylinder, a-cylinder--head,-a
valve-block-interposed-between-the-eylinder-and-head--and--having--e--longitudinal
bore-forming-a-continuation--of-the-piston--chamber--in-the-eylinder, and--a-valve
loeated-in said valve-block-and consisting-of-a-cylindrical shell-adapted-to-have-the
piston-pass-through-it-at-the-end-of-its-rearward-stroke, and provided-with-opposing

page_text: pressare-areas-to-which-the-motive-fluid-is-admitted-for-shifting the valve-in-opposite
directions.
20. In-a-pnenmatie-hammer,-the-combination-of--a--cylinder, a-cylinder-head,-a
valve-block-interposed-between-the-eylinder-and-head--and--having--a--longitudinal
bore-forming-a-continuation--of-the-piston--chamber--in-the--eylinder, and--a-valve
loeated-in-said-valve-block-and-consisting-of-a--eylindrical shell-adapted-to-have-the
piston-pass-through-it-at-the-end-of-its-rearward-stroke-and-provided--with-differen-
tial pressure-areas-to-the-smaller-one-of-which-the-motive-flaid-is-constantly-admit-
ted-through-an-inlet-in-the-cylinder-head-and-to-the-larger-one-of-which-tho-motive
fluid-is-intermittently-admitted-through-a-passage-controlled-by-the-piston:
30. In-a-pneumatic-hammer, the-combination-of-a-cylinder,-eylinder-head, valve
block-confined-between-the-cylinder-and-head-and--having a longitudinal-bore-form-
ing-a-continuation--of-the-piston chamber-in-the-cylinder, and a valve-located-in-said.
valve-block-and-consisting-of-a-cylindrical--shell adapted to have-the-piston--pass
through-it-at-the-end-of-its-rearward-stroke;-and-provided-with-differential-pressure
areas,-to-the-smaller-rear-one-of--which--the--motive--flaid--is--constantly--admitted
through-a-series-of-ports-registering-with-a--circular--groove-in--the--eylinder-head;
and-to-the-larger-forward-one-of-which-the-motive--fluid is--intermittently-admitted
through-a-passage-controlled-by-the-piston.
31. In-a-pneumatie-hammer-the-combination of-a-cylinder--having--an external
annular-flange-at-its-rear-end,-a-eylinder--head-having a-forwardly-projecting-cylin
drical-eap-provided-with-serew-threads,-a-threaded-coupling--sleeve-engaging-said
eap-and-provided at-its-front-end-with-an-internal-annular-flange--engaging-the-ex-
ternal-flange-upon-the-rear-end-of--the-cylinder, a--eylindrical--valve--bleek--fitting.
within-the-coupling-sleeve-and-cap-and-confined-by-them-between--the eylinder-and
eylinder-head, said-valve-block-having-a-longitudinal--bore--forming-a-continuation:
of-a-piston-chamber-in-the-eylinder,-and-a-valve--located--in--said-valve-block-and
consisting-of-a-eylindrical-shell-adapted-to-have--the--piston--pass-through-it-at-the
end-of-its-rearward-stroke-and-provided-with--opposing-pressure-areas-to-which-the
mo:ive-fluid-is-admitted-to-shift-the-valve-in-opposite-directions.
32. In-a-valve-mechanism-for--pneumatic-hammers--for--controlling--the-move-.
ments-of-a-piston,-a-valve-having-differential-pressure--areas-to-the-smaller-one-of.
and-to-the-larger-one-of-which-the-motive-fluid--is-intermittently-admitted, -to-move.
the-valve-in-the-opposite-direction,-and-an--auxiliary--passage-opened -by-the-last
mentioned-movement-of-the-valve-to-admit-an-additional-supply--of--motive-fluid-to.
wich-the-motive-fluid-is-constantly-admitted-to-press the--valve--in-one-directions.
said-larger-area-of-the-valve.
33.-in-a-valve--mechanism -for--pneumatie--hammers--for--controlling-the-move..
ments-of-a-piston,a-valve provided-with-differential--pressure--areas-to-the-smaller
the last
fluid-to
one-of-which-the-motive-fluid-is-constantly-admitted-to-press-the-valve-in-one-diree-
tion;-and-to-the-larger-one-of-which-the-motive--flaid-is--intermittently-admitted,-to
move-the-valve-in-the-opposite--direetion,-an-auxiliary-passage--opened by
mentioned-movement-of-the-valve-to-admit-an--additional--supply-of-motive
said-larger-area-of-the-valve-and-a-passage-leading from said larger area of the valve,
to-one-end-of-the-piston-chamber, through--which--motiv-fluid supplied-by-the
auxiliary-passage-may-be-admitted-to-said-end--of-the--piston-chamber-to-move-the
piston-toward-the-opposite-end-of-said-chamber:
34. In-a-valve-mechanism--for--pneumatic-hammers--for-controlling-the-move-
ments-et-a-piston,-a-valve-provided-with--differential--pressure--areas-to-the-smaller
of-which-the-motive-fluid-is-eonstantly-admitted-to--press-the-valve-in-one-direction;.
and-to-the-larger-one-of-which-the-motive-fluid-is--intermittently--admitted throngh
a-passage-controlled-by-the-piston,-to-move-the-valve-in-the-opposite-diree ion,-and
an auxiliary passage-opened-by-the-last-mentioned-movement-of-the-valve-to-admit.
an-additional-supply-of-motive-fluid-to-the-larger-area-of-the--valve, said
passage-exeeeding-in-capasity the-said-passage-controlled-by-the-piston
auxiliary.
35. In-a-valve mechanism-for-pneumatie--hammers--for-controlling--the--move-.
ments-of-a-piston,-a-valve-consisting of-a-cylindrical shell-1. eated-in-the-piston cham-

page_text: directions.
ber-and-adapted-to-have-the-piston-pass-through-it--and--provided--with-opposing
pressure-areas-to-which-the-motive fluid-is-admitted to shift the valve-in-opposite
35-36-In-a-valve-mechanism--for-pneumatic-hammers-for-controlling the move.
ments-of-a-piston;-a-valve-consisting-of-a-cylindrical--shell--located--in--position--to
have-the-piston-pass-through-it-and-provided-with-differential-pressure-areas-to-te
smaller-one-of-which-the-motive-flaid-is-constantly-admitted-to--press-the--valve-in
one-direction;-and-to-the-larger-one-of-which-the-motive-fluid-is--intermittently--ad-
mitted to-move-the-valve-in-the-opposite-direction.
36 37. In-a-valve-mechanism for-pneumatic-hammers-for-controlling-the-move-
ments-of-a-piston,a-valve-located-in-the-pisten-chamber-and-consisting--of-a-eylin-
drical-shell-adapted-to-have-the-piston pass-through-it,-and-provided-with-differen
tial-pressure--areas-to-the-smaller-one of which-the-motive-fluid-is-constantly-admit-
t-d-to-press-the-valve-in-one-direction,-and-to-the-larger--one-of--which--the-motive
fluid-is-intermittently-admitted,-to-move-the-valve-in-the-opposite-direction;-and-an
auxiliary passage-opened by the-last-mentioned--movement-of-the-valve-to-admit-an
additional--supply-of-motive fluid-to-the-arger-area-of-the-valve;
37 38. In-a-valve-mechanism-for-pneumatic-hammers-for-controlling-the-move-
ments-of-a-piston,-a-valve-located-in-the-piston-chamber-and-consisting-of-a cylin-
drical shell-adapted-to-have-the-piston-pass--through-it,-and-provided-with-differen-
tial pressure-areas-to-the-smaller-one-of-which-the-motive-fluid-is-constantly-admit-
ted; to-press-the--valve-in-one-direction, and-to-the-larger-one-of-which-the-motive
fluid--is-intermittently-admitted, to-move-the--valve--in--the--opposite-direction,--an
auxiliary passage--opened -by-the-last-mentioned--movement-of-the-valve,-and--an
outlet-passage-from--the--larger-area--of-the--valve--for-conveying-to-one-end--of
38-30-In-a-valve-mechanism-for-pneumatic-hammers-for-controlling-the-move-
ments-of-a-pisten;-a-valve-lecated in the rear-end-of-the-piston chamber-and-consist-
ing-of-u-eylindrical shell-adapted-to-have-the-piston-pass-through-it-at-the-end-of-its
rearward-stroke;-and-provided-with-differential-pressure-areas-to--the-smaller-one-of
which-the-motive-flaid-is-constantly-admitted;-to-press-the-valve-forward, and-to-the
larger-one-of-which-the-motive-fluid-is--intermittently--admitted--through-a-passage
the--piston-chamber--motive-fluid-supplied-by-said-auxiliary-passage.
controlled-by-the-piston;-to-move-the-valve-rearward said--valve--when--moved-for-
ward by-the-constantly-acting-pressure-against--its-smaller-area-opening-an-annalar
port-around-its-rear-end-to-admit-the--motive--fluid-to-the--rear--end--of--the--piston
chamber,-and-when-moved-in-the-opposite--direction -by--the--intermittent-pressure
admitted-to-its-larger-area-opening-a-passage-leading to-the-front-end--of-the-piston
chamber.
30-40.-The-herein-described-valve,-for-a--pneumatie--hammer-consisting-of-the
eylindrical-shell-O-having-the-ring-b--provided-with-the-porte-l-and-the-differential
pressure-arean-c-d.
40-44-The-herein deseribed-valve-for-a-pneumatic--hammer, -consisting of the
eylindrical shell-O having-the-eireumferential groove a;-the-projecting-ring-b-provi
ded-with-the-ports-1;-and-the-differential-pressure-areas-c-d.
41-42 In-a-pneumatie--hammer-the--combination--of-the-valve-block-having
the-internal eireumferential groove-h-open-to-the--exhaust,--of-the-valve--located in
said-bleek-and-consisting-of-the-cylindrical--shell-O-having-opposing-pressure-areas
to which-the-motive-fluid-is-admitted,to-shift-the-valve--in--opposite-directions;-and
provided-with-the-ring-b-having the-ports-/-adapted-to--register--with--the-exhaust
groove-h-when-the-valve-is-in-one-position.
42-43. In-a-pneumatie-hammer-the-combination--of-the-valve-block-having-the
internal-eireumferential-grove-h-open-to-the-exhaust,-of-the-valve--located--in-s id
bleek-and-consisting-of-the-cylindrical-shell--0--having--opposing--pressure-areas-to
which-the-motive-fluid-is-admitted-to-shift-the-valve-in-opposite-directions, and pre
vided with-the-ring-b--having-the-porte----adapted--to-register--with--the--exhaust
groove-h-when-the-valve-is-in-one-position;-said-valve when-in-its-opposite-position

page_text: cutting-of-communication-with-the-exhaust-groove-h-and-opening-the-annular-port-p
Brennd-its-end-to-admit-the-motive-fluid-to-its-interior.
43-44. In-a-pneumatie-hammer--the-combination,with-the-valve-block;-of--the
valve-leeated-therein-and-consisting-of-the-cylindrical--shell--O-having--the--ring--b
provided--with--the-ports-l;-and-the-differential-pressure--areas-c-d-and--said--block
having-the--cireumferential--exhaust--groove-h-co-operating- with--the-ports-/-in-the
valve-the-inlet-passage-U-and-exhaust--passage--P--communicating with-the-pres-
Euro-area-c--of--the--valve;-and-the-inlet-ports--W-communicating-with-the-pressure
area-d-of-the-va.ve.
44-45-In-a-pneumatie-hammer-the-combination,--with-the-valve--bleek,-of-the
valve-loentod-therein-and-consisting-of-the-eylindrical-shell-O-having-the-ring-b-pre-
vided-with-the-ports--1,-and-the--differential-pressure-areas-c-d,-and-said-valve-block
haring-the-circumferential-exhaust-groove--h-co-operating--with--the--ports-l-in-the
valve; the-passages-and-P-communicating-with-the-pressure--area-c-of-the-valve,
the-inlet-ports--communicating-with-the-pressure-area--d--of--the--valve;-and-the
auxiliary-passage-X-communienting-at-one-end-with--the-inlet--ports--W--and-at-its
other--with-the-space-e-adjacent--the-pressure-area-c-of-the-valve:
45-46. In-a-pneumatie-hammer-the--combinatiou,-with--the-valve-block;-of-the
valve-loeated therein-and-consisting-of-the-eylindrical-shell-O-having-the-ring-b-pro-
vided-with-the-ports-l;-and--the-differential-pressure--areas-c-d-and-said-valve-bloek
having-the-cireumferential-exhaust-groove-h--ee-operating--with-the--ports-l-of-the
valves-the-inlet-passage-U-and-exhaust-passage-P-communicating-with-the-pressure
arca-c-of-the-valve, the-inlet-ports-W-esmmunicating-with-the-pressure-area-d-of-the
valve,-the-auxiliary passage X-communicating-at-one-end-with-the-inlet-ports-Wund
at-its-other-with-the-space-e-aijaeent-the-pressure-area-c-of-the-valve, and-the outlet
passage-S-leading-from-the-spn-e-c-to-the-piston-ehamber.
46-47 In-a-pneumatic-hammer-the--combination,-with-the--valve-block;-of the
valve-located therein-and-consisting-of-the--eylindrical-shell-O-having-the-externa!
eireumferential-groove-a,-the-differential-pressure-areas-c-,-and-the-ring-b-provided
with-the-ports-l-and-suid-valve-block--having--the--eircumferential-grooves-m-n-and
passages R-and-o-co-operating-with-the-groove-a-of--the--valve--the-circumferential
exhaust-groove-h-eo-operating-with-the-ports-l-in-the-valve,-the-inlet-passage-U-and
exhaust-passage-P-eommunien ing-with-the-larger-area--c--of--the--valve,--and--inlet
ports-W-communieating-with-the-smaller-area-d-of-the-valve.
47-48. In-a-pneumatic-hammer-the-herein--described-valve-block,-composed-of
the part-I-bored-to-different-diameters-and-the-part-1'-fitting--against--the--end-ot
the-part-1-and-provided-with-the-proje ting--annular--Bange--or--ring--I"-fitting-the
larger-bore-of-the-part-1-the-part-1-being provided--in--its--larger-bore-with-the-eir-
cumferential groove-k-communicating-with-the-exhaust-ports-i,-and-the-part-1'-being
provided-with-the-inlet-ports W.
48-49. In-a-pneumatic-hammer-the-herein-deseribed--valve-block,-composed-of
the part-I-bered-to-different-diameters;-and-the-part-1-fitting-against-the-end-of-the
part-1-and-having the-projecting-annulur-flange-1"-entering-the--larger--bore-of-the
part I,-the-part-I-being provided-with-the-circumferential--grooves--m-n-in-its-smal-
ler-bere-and-the-eircumferential-greove--h-in-its--larger-bore, the--grooves-n-and-h
communieating-with-the-exhaust-ports;-the-part-1-being-also provided-with-the-pas-
sages-P-U-communicating-with-its-larger-bore,-and--with-the-passage-R-communi-
cating with the groove-m-and-the-part-1-being-provided-with-the-inlet-ports-W
49 50. In-a-pneumatic-hammer-the-herein-described-valve-bleek,-composed-of
the-part-1-bored-to-different diameters, and-the-part-1-fitting-against-the-end-of-the
part-I-and-having-the-projecting-ring-I"-entering--the-larger-bore-of-the-part-I; and
having-the-inlet-ports-W-opening-through said-ring, the-part--I-having-the-circum-
ferential-grooves-m-n-in-its-smaller--bore-and-the--cireumferential-groove-h-in--its
eommunicating--with--the-groove-n,and-the-exhaust-port-i-communicating-with-the
larger--bore--the--passage-R communicating-with-the-groove-m;-the-exhaust-port-o
groove-h-the-passages UPS-eemmunicating--with-the-larger--bore-sf-the--part-I,
and--the--passage--X--communicating--with-the-inlet-port W.

page_text: 50-51. A-pneumatie hammer-provided at its front-end-with-a-tool-receiving-bare
adapted-to--receive--and--be
elosed-by-the-shank-of-the-working-tool,-and-having-a--passage--for--admitting-the
motive-fluid-to-the-front-end-of--said--piston--chamber, whereby-the-thank--of-the
opening-into-the-front-end-of-the-piston--chamber-and-
working-teel-is-made-to-form-part-of-the-end--wall-of--the--piston--chamber-against
which-the-motive-fluid-aets-to-force-the-piston-rearward:
5152 A-pneumatie-hammer-having-a-piston-chamber-whose--front-end-is-par-
tially-elosed-by-an-annular-shoulder-surrounding-an-opening-adapted-to-receive-the
shank-of-the-working-tool, und-having-a-passage-for--admitting--the-motive-fluid-to
the--trout--end--of--said-piston--chamber, whereby-the-shank-of-the-tool-is-made-to
form-part-of-the-end-wall-of-the-chamber--against-which--the--motive--fluid-aets-te
feree-the-piston-rearward.
0-32 53. A-pneumatis-hammer-having-a-piston--chamber-whose-front-end-is
partially-closed-by-an-annular-shoulder-surrounding-an--opening--adapted to-receive
the-shan-of-the-working-to-1,-so-that-said-teel-forms-part--of--the--end--wall-of-the
piston-ehamber-against-which-the-motive-fluid-aets-to-force--the-piston--rearward.-in
combination-with-a-piston-provided-upon-its-front-end-with-a-projecting-stem-adap-
ted-to enter-and-fit-said-tool-receiving-opening-when-the-absence-of-the-working-tool
frem-position-to-receive-the-blows-of-the--piston--permits--the--latter--te--make--an
abnormal-forward-stroke, whereby--the--piston--is--eushioned-at--the--ends--of--such
strokes-and-not-permitted-to-strike the-end-of-the-piston-chamber.
51-53-54 A-pneumatic-hammer-having-a-piston--chamber-whose-front-end-is
partially-elsed-by-the-integral-annular-shoulder-J-surrounding-the-opening-adapted
to-which-receives the shank of an unconnected-and removable-the-working teel-L, and
having-the-passage-R-for-admitting-the-motive-fluid-to-the-front-end-of-the--piston
chomber-where-it-may-act-upon-the-shoulder-J-and-shank-of-the-tool-L-to-force-the
piston-rearward.
52-54-55.-A-pneumatic-hammer-whose-piston-chamber--is--partially-elosed-as
its-front-end-by-the-integral-annular-shoulder J-surrounding the tool receiving-open
ing,-and-whese-front-end-is-provided with- a-bore--into--which--is--driven--the-chisel
sleeve,-and-which-is-provided-with-the-passage-R-for-admitting-motive--fluid-to-the
front end-of-said piston-chamber, the-chisel-sleeve-and--the--opening--surrounded by
the-shoulder J-being-adapted-to-receive-the-shank-of-an-unconneeted-and-removable
the--working--tool-L,-whereby-the-latter-is-made-to-form-part-of-the-end-wall-of-the
53-55-56.-A-pneumatic-hammer-whese-piston-chamber-is--partially--elosed-at
its-front-end-by-the-annular-shoulder-J-adapted-to-receive-the-shank-of-the-working
tool-L-and-which-has-the-passage-R-for-admitting-motive--fluid-to--the-front-end-of
said-ehamber,-in-combination-with-the-piston--M--having--the--stem--N-adapted-to
enter-and-fit-the-opening-surrounded-by-the-shoulder-J-when--the--absence--of--the
tool-L-frem-working-position-permits-the--piston--to--make-an--abnormal--forward
piston-chamber-against-which-the-motive-fluid acts-to-drive-the-piston-rearward.
streke, whereby-the-piston-is-eushioned-at the-ends-of--such-strokes,-and-prevented
from-striking-the-shoulder-J.
54-56-57-In-a-pneumatie-hammer-the-combination,-with-the-coupling-sleeve
having-the-internal-serrated-flange,-of-a-leeking-member-seated-in-a-recess-beneath
said-flange-and-pressed-outward-inte-leeking--engagement-with-the-flange-by-means
of-a-spring-said-locking member-being-adapted-to--be-depressed-out-of-engagement
with-the-flange-and-turned-in-its-recess,-and-means-for-holding-it-in-such-disengaged
position:
55-57-58.-In-a-pneumatie-hammer-the--combination, with the coupling-sleeve
having-the-internal-serrated-flange,-of-a-locking-member-seated-in-a-recess-beneath
the-flange-and-pressed-outward-inte-locking-engagement-with--the--flange-by-means
of-a-spring, said-locking-member-being-provided-with a shoulder-and being adapted
to-be-pressed-inward out-of-engagement-with--the--flange--and--turned-in-its-recess,
and-means-eo-operating-with-its-shoulder,-when--so--depressed--and-turned,-to-hold
the-member-out-of-engagement-with-the-flange.

page_text: 56-58 59-In-a-pneumatie-hammer-the-combination,-with-the-eylinder-A-har-
ing-the-aanular-Hange-B;-and-the--coupling--sleeve--C--provided--with--the--internal
flaug co-operating-with-the-flauge-B-serrated-upon--its-inner--edg-of-the-locking-
block-Y-seated-in-a-recess-in-the-wall-of-the-cylinder-A-and-provided-upon-its-uppеr
er-outer-end-with-one-or-more-teeth-to-co-operate-with-the-serrations-of-the-eupling
sleeve;-the-spring-Z-beneath-said-locking-block;-and-the--pin--6--eo-operating-with
the-shoulder-d-of-the-locking-block-to-maintain-the-latter-out-of-engagement-with
substantially--as-and-for-the-purpose-described.
the-eeupling-sleeve,
Dated this 29th day of October 1896.
HERBERT HADDAN & Co.,
Agents to the Applicant,
18 Buckingham Street, Strand, London. W.C.