Improvements in and connected with Pneumatic Power Hammers.
Year: 1897

page_text: Date of Application, 3rd June, 1897
Complete Specification Left, 1st Apr., 1898-Accepted, 7th May,
1898
PROVISIONAL SPECIFICATION.
Improvements in and connected with Pneumatic Power Hammers.
I, WILLIAM DREDGE PLAYER, of Lionel Street, in the City of Birmingham,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has reference to that class of pneumatic power hammers in
which a rapidly rising and falling air cylinder contains the piston which carries
the hammer or tup, the said cylinder being arranged to trap the air above or
below the piston to form air cushions when the blow is being delivered and when
the hammer is being raised and this invention consists of the herein. described
improved construction and arrangement of the valve and ports and valve operating
mechanism by which the quantity of air imprisoned under the piston and the
consequent stroke of the hammer or tup can be easily regulated by the operator
to enable him to deliver a light or heavy blow as the nature of the work may,
require.
In carrying out this invention I provide in the air cylinder a series of air out-
let holes or passages one above the other at certain intervals apart terminating
in air ports in the cylinder face where the slide valve is situated. I provide a
slide valve in which are narrow slots or openings corresponding in number with
the said air ports in the cylinder face but not arranged at the same distances apart
but the slots or openings in the slide valve are somewhat nearer together than
are the ports in the cylinder face so that only one of the said air ports in the
cylinder will be uncovered by the slide valve at any time. For instance the air
ports and openings are so arranged that when the first opening in the valve corres-
ponds with the first or lowest port in the cylinder so that this port is open, all
the other ports are closed; and when the slide valve has been moved through a
short space to bring the second opening of the valve opposite to the second port
of the cylinder the first port and all the other ports will then be closed, and so on
with all the other ports; a certain regular further movement of the valve in one
direction gradually opening the ports one after the other reckoning upwardly from
the bottom port, and a movement of the slide valve in the opposite direction open-
ing the ports one after the other reckoning downwardly from the top port. Thus
a proper movement of the slide valve whilst the hammer is at work will cause
any one of the series of air ports to be opened and thus determine the point at
which the escape of air from below the piston is to be arrested and regulate the
stroke. of the hammer. For instance if a heavy blow is required the slide valve
will be moved by the operator so as to open the bottom port of the cylinder and
thus trap a small volume of air below the piston so that the piston and hammer
can descend to their lowest extent, then to give a lighter blow the slide valve has
to be moved so as to open one or other of the higher ports of the cylinder and
entrap a larger volume of air and thus prevent the piston and hammer from
descending so far.
By arranging the openings in the slide vale to differentiate with the air ports
of the cylinder as above described a very small movement of the valve is required
to open any of the ports and the valve operating mechanism is more simple and

page_text: the hammer is under more perfect control than when as in some pneumatic
hammers the valve has to be turned through a very considerable angle to vary
the blow.
The said slide valve and the ports in the cylinder face may be arranged in
various ways, that is to say, the slide valve may be arranged to move to and fro
vertically or horizontally or in an inclined direction or it may be made to slide
by turning in a circular direction as about a central pin or the slide valve itself may be
of a cylindrical form and the valve face and ports therein made to correspond, the
opening of the ports being regulated by a sliding turning movement or by a slid-
ing longitudinal movement of the valve. What I prefer is for the slide valve to
be constructed as a circular plate to turn about a central pin the ports of the
cylinder and of the valve being arranged in about a semi-circle on one side of
the centre. The turning of the valve may in this case be controlled by a short
crank which has a crank pin working up and down in a vertical slot in a guide
bar which is carried by parallel links turning on centres fixed to the hammer frame
which links are connected by suitable rods or otherwise to a treadle, so that the
workman by slightly moving the treadle can alter the position of the guide bar
relatively to the valve, and thus impart an angular sliding movement to the valve
causing the same to turn and slide over the cylinder face and to open the proper
port corresponding with where the escape of air from underneath the piston is
to be cut off.
Dated this 1st day of June 1897.
Improvements in and connected with Pneumatic Power Hammers.
I, WILLIAM DREDGE PLAYER, of Lionel Street, in the City of Birmingham,
Engineer, 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:-
.C
This invention has reference to that class of pneumatic power hammers in
which a rapidly rising and falling air cylinder contains the piston which carries.
the hammer or tup, the said cylinder being arranged to trap the air above or
below the piston to form air cushions when the blow is being delivered and when
the hammer is being raised and this invention consists of the hereindescribed
improved construction and arrangement of the valve and ports and valve operating
mechanism by which the quantity of air imprisoned under the piston and the
consequent stroke of the hammer or tup can be easily regulated by the operator
to enable him to deliver a light or heavy blow as the nature of the work may
require.
In carrying out this invention I provide in the air cylinder a series of air out-
let' holes or passages one above the other at certain intervals apart terminating
in air ports in the cylinder face where the slide valve is situated. I provide a
slide valve in which are narrow slots or openings corresponding in number with
the said air ports in the cylinder face but not arranged at the same distances apart
but the slots or openings in the slide valve are somewhat nearer together than
are the ports in the cylinder face so that only one of the said air ports in the
cylinder will be uncovered by the slide valve at any time. For instance the' air
ports and openings are so arranged that when the first opening in the valve corre-
sponds with the first or lowest port in the cylinder so that this port is open, all

page_text: the other ports are closed; and when the slide valve has been moved through a
short space to bring the second opening of the valve opposite to the second port
of the cylinder the first port and all the other ports will then be closed, and so on
with all the other ports; a certain regular further movement of the valve in one
direction gradually opening the ports one after the other reckoning upwardly from
the bottom port, and a movement of the slide valve in the opposite direction clos-
ing the ports one after the other reckoning downwardly from the top port. Thus
a proper movement of the slide valve whilst the hammer is at work will cause
any one of the series of air ports to be opened and thus determine the point at
which the escape of air from below the piston is to be arrested and regulate the
stroke of the hammer. For instance if a heavy blow is required the slide valve
will be moved by the operator so as to open the bottom port of the cylinder and
thus trap a small volume of air below the piston so that the piston and hammer
can descend to their lowest extent, then to give a lighter blow the slide valve has
to be moved so as to open one or other of the higher ports of the cylinder and
entrap a larger volume of air and thus prevent the piston and hammer from
descending so far.
On the accompanying drawings Fig. 1 is a back elevation of the air cylinder of
a pneumatic power hammer with my invention applied; Fig. 2 is a cross sectional
elevation of the same; Fig. 3 is a sectional plan of the same on line X X of Figs. 1
and 2; Fig. 4 shews the same parts as Fig. 1 but with the slide valve and its
operating mechanism in a different position; Fig. 5 is a back elevation and Fig. 6
is a side elevation of the cylinder of a pneumatic power hammer with another
form of my invention applied thereto; Fig. 7 is a sectional plan of the same on
line YY of Fig. 5; Fig. 8 is a back elevation of another cylinder of a pneumatic
power hammer with a further modification of my said invention applied thereto;
Fig. 9 is a sectional plan of the same on line Z Z of Fig. 8; Fig. 10 is a back view
of the said cylinder shewn in Figs. 8 and 9 without the air escape valve which
latter is shewn separately by Fig. 11; Fig. 12 is a sectional back elevation of the air
cylinder of a pneumatic hammer with a modification of my said invention applied
thereto and Fig. 13 is a sectional plan of the same on line W W of Fig. 12.
The same letters of reference indicate the same or corresponding parts in all
the figures of the drawings.
Referring firstly more particularly to the arrangement of my invention shewn by
Figs. 1, 2, and 3, A is the air cylinder which moves rapidly up and down in the
usual way, B is the piston in the air cylinder and 61 is the piston rod which carries
the hammer or tup at its lower end. The series of air outlet holes or passages,
in this case seven in number, are marked respectively c¹ c² c3 c4 c5c6c7 arranged
one above the other at short intervals apart and terminating respectively in the
seven air ports d¹ d² d³ d¹ d³ do in the cylinder face a¹ where the slide valve E
is situated and which latter has narrow slots or openings, in this case seven in
number, corresponding with the seven air ports in the cylinder face these air slots
or openings of the valve E being respectively marked e¹ e e e e e e and they
are arranged at regular intervals apart somewhat nearer together than are the
ports d d d d d d d in the cylinder face a¹ so that only one of the seven
ports d¹³d d³ d d will be uncovered by the slide valve E at any time. The
slide valve E moves up and down with the cylinder A and is supported against
the valve face a¹ of the cylinder by the rebated guides a³ a between which the
slide valve E fits and by the bell crank lever F which is connected to the slide
valve E by the pin es fixed to the slide valve and engaging in the slotted end f¹
of the bell crank lever F, this lever F turning on a fulcrum pin f fixed to the
cylinder A. The pin f³ at the end of the other arm of the lever F engages in the
vertical slot g' of the guide bar G which is carried by and jointed to the ends of
the two parallel links H¹ H arranged one above the other and turning on
centres h¹h fixed to the stationary hammer frame I. The link H is jointed to
the rod J which at its lower end is connected to the usual treadle or lever (not
shewn on my drawings) by which the workman regulates the force of the blow

page_text: delivered by the hammer or tup. As the slot g¹ is parallel with the line of motion
of the cylinder A it follows that so long as the guide bar G remains stationary
the pin of the lever F will move up and down the slot g¹ without imparting
any movement to the slide valve E relatively to the cylinder A but by the work-
man slightly moving the treadle so as to depress the rod J from the position shewn
by Fig. 1 the guide bar G and the end of the lever F will be moved slightly
nearer to the vertical centre line of the cylinder A and the valve E will be corres-
pondingly raised through a short space and in the same way when the workman
moves the treadle so as to raise the rod J and guide bar G a corresponding down-
ward movement of the valve E on the valve face a¹ is effected.
The parts above described act as follows:-When it is desired to trap the smallest
quantity of air under the piston B and deliver the heaviest blow the workman
by the treadle moves the rod J so that the guide bar G will occupy the position
shewn by Fig. 1 and the bottom slot e¹ of the slide valve E will correspond with
the air outlet port d¹ of the bottom hole c¹ in the cylinder A as shewn in Figs. 1
and 2 and all the other air ports d³ d³ d4 d5 do 7 will now be closed as they do
not correspond with any of the openings e e e e e e of the slide valve E. To
entrap a larger quantity of air under the piston B and deliver a lighter blow the
slide valve E has to be moved upwardly through a short space so as to bring say
the next higher slot e² of the valve E opposite to the second air outlet port da as
shewn in Fig. 4 and now the air will escape through the port d³ as the first port d'
Thus the
and all the other ports d³ d d d d will be closed by the valve E.
proper movement of the valve E by the rod J whilst the hammer is at work will
cause any one of the series of air ports d¹ da d³ d d d d to be opened whilst the
others are closed and thus determine the point at which the escape of air below
the piston B is to be arrested and regulate the stroke of the hammer.
By arranging the openings e¹ es e³ et e5 e6 e7 of the slide valve E to differentiate
with the air ports d' d² d³ d d d d of the cylinder A as above described, a very
small movement of the valve E is required to open any one of the air ports d¹ d² ds
dddd and thus the mechanism for operating the valve E is more simple and
the hammer is under more perfect control that when, as in some pneumatic hammers,
the valve which regulates the escape of air from the cylinder has to be turned
through a very considerable angle to vary the blow.
It will be evident that the said slide valve made with the narrow slots or open-
ings to differentiate with the ports d¹ dª d³ d¹ d5 d d in the cylinder face may
be arranged in other ways than that shewn by Figs. 1, 2, 3 and 4 without departing
from the nature of my invention, for instance as shewn by Fig. 5 the slide valve E
may be arranged to move to and fro horizontally. Or the slide valve E may be
arranged to move in an inclined direction, or as represented by Figs. 8, 9, 10 and 11
the slide valve may be made to turn in a circular direction about a central pin K,
or as in the arrangement represented by Figs. 12 and 13 the slide valve E may be
of cylindrical form and the valve face and air ports therein made to correspond,
the opening of the ports being regulated by a sliding longitudinal movement of
the valve. These modifications of my invention I will now proceed to more par-
ticularly describe. .
It will be seen that in the arrangement shewn by Figs. 5, 6, and 7 the slide
valve E is of similar construction to that shewn by Figs. 1, 2, 3 and 4 but is
arranged to work in horizontal guides a³ a* of the cylinder A. and the valve face a¹
is made with the seven outlet ports d¹ d³ d³ d' da do d' communicating respectively
with the seven outlet holes c¹ c³ c3 c4 c5 c c7 of the cylinder. In this arrangement
the lever F is not required to be bell cranked but is a straight lever as shewn turn-
ing about the fulcrum pin f, fixed to the cylinder A so that as the rod J and guide
bar G are moved downwardly from the position shewn by Fig. 5 the slide valve E
will be moved towards the left hand of Fig. 5 and cause a larger quantity of air
to be entrapped under the piston and when the rod J and guide bar G and
links H¹ H² are moved upwardly the slide valve E will be caused to move towards

page_text: the right hand side of Fig. 5 and thus cause a smaller quantity of air to be
entrapped underneath the piston B.
In the arrangement of my invention shewn by Fig. 8 where the slide valve E
is made as a circular plate to turn about the central pin K, the air outlet ports d
dddddd in the valve face a¹ are arranged in about a semicircle on
one side of
the centre pin K and the slots e¹ e² e³ e¹ e5 e6e7 in the slide valve E are also arranged
in about a semicircle the same side of the centre pin K as shewn in Figs. 8 and 11.
The turning of the valve E is effected and controlled by the short crank L fixed
to the valve E and made with a crank pin e8 at one end to work up and down the
vertical slot g¹ of the guide bar G so that when the rod J and links H¹ H² and
guide bar G are depressed the valve E will thereby be caused to turn in the
direction indicated by the arrow on the right hand side of Fig. 8 to entrap a larger
quantity of air underneath the piston B, and when the rod J and links H¹³
and guide bar G are. moved upwardly the slide valve E will be caused to turn
in the direction indicated by the arrow on the left hand side of Fig. 8 and thus
entrap a smaller quantity of air under the piston B and deliver a heavier blow.
It will be understood that my invention is not limited to any particular number
of air holes e c3 c4cc6c7 and corresponding air ports d¹ d² d³ d4 d5 de d7 in the
cylinder face a¹ and slots el es e³ et e5 e6 e in the slide valve E as the number of
these will vary according to circumstances as will be easily understood.
The
In the arrangement of my invention shewn by Figs. 12 and 13 the slide valve E
is made of cylindrical form fitting in a cylindrical casing M the interior of which
forms a cylindrical facing a¹ provided with the air outlet ports d¹ d³ d³ d' d³ de d
communicating with the air outlet holes cl c² c³ c¹ c5 c6 c² of the cylinder A.
cylindrical valve E is hollow and open at the top or at the bottom for the escape
of the air and is made with narrow slots e¹ e³ ³ et es e6e7 arranged as above described
to differentiate with the air outlet ports d¹ d² d³ d¹ d³ do 7 of the cylinder and is
operated by similar means to those above described with reference to Figs. 1, 2, 3
and 4.
The accompanying drawings illustrate what I consider to be the best ways of
carrying my invention into practice but it will be evident that my said invention
is not limited to the precise details shewn.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I would have it understood
that I am aware that prior to my said invention the rapidly rising and falling air
cylinder of a pneumatic power hammer has been made with a series of air outlet
holes one above the other communicating with outlet ports controlled by a valve
operated by the workman so as to vary the volume of air below the piston and I
do not make any broad claim to this but I declare that what I claim is:
1. In a pneumatic power hammer the employment of an air cylinder made with a
series of air outlet holes or passages one above the other at certain intervals apart
terminating in corresponding narrow air ports in the cylinder face, in combina-
tion with a slide valve arranged to work on said cylinder face and made with a
series of narrow slots or openings corresponding in number but differentiating
with the said air ports the said slide valve being provided with means for hold-
ing it in any desired position relatively to the cylinder face and for moving the
slide valve thereon so as to make any one of the slots of the slide valve open a
corresponding air port of the cylinder to the atmosphere whilst all the other air ports
are closed thus enabling the quantity of air imprisoned under the piston in the
cylinder and the consequent stroke of the hammer or tup to be easily regulated by
the operator all substantially as hereinbefore set forth.
2. In a pneumatic power hammer the employment of the air cylinder A made
with a series of air outlet holes one above the other at certain intervals apart
terminating in corresponding narrow horizontal air ports in the cylinder face, in
combination with the slide valve E arranged to work vertically on the cylinder
face and made with a series of narrow 'horizontal slots or openings corresponding

page_text: in number but differentiating with said air ports, the said slide valve being con-
nected to the bell crank lever F which is carried by the cylinder and engages with
and is adapted to move up and down the vertical slot g¹ of the guide bar G which
is carried by parallel links H¹ H2 and is connected to a treadle rod by moving
which the guide bar will so act upon the bell crank lever as to move the slide valve
on the cylinder face and make any one of the slide valve slots open the correspond-
ing air port of the cylinder to the atmosphere whilst all the other air ports are
closed, thus enabling the quantity of air imprisoned under the piston in the
cylinder and the consequent stroke of the hammer or tup to be easily regulated
by the operator, the said parts being arranged and acting substantially as herein-
before described and illustrated by Figs. 1, 2, 3 and 4 of the accompanying
drawings.
3. In a pneumatic power hammer the employment of the air cylinder A made
with a series of air outlet holes one above the above at certain intervals apart
terminating in corresponding narrow vertical air ports in the cylinder face, in
combination with the slide valve E arranged to work horizontally on the cylinder
face and made with a series of narrow vertical slots or openings corresponding in
number but differentiating with said air ports, the said slide valve being con-
nected to the lever F which is carried by the cylinder and engages with and is
adapted to move up and down the vertical slot g¹ of the guide bar G which is
carried by parallel links H1 H2 and is connected to a treadle rod by moving
which the guide bar will so act upon the lever as to move the slide valve on the
cylinder face and make any one of the slide valve slots open the corresponding
air port of the cylinder to the atmosphere whilst all the other air ports are closed,
thus enabling the quantity of air imprisoned under the piston in the cylinder and
the consequent stroke of the hammer or tup to be easily regulated by the operator,
the said parts being arranged and acting substantially as herein before described
and illustrated by Figs. 5, 6 and 7 of the accompanying drawings.
4. In a pneumatic power hammer the employment of the air cylinder A made
with a series of air outlet holes one above the other at certain intervals apart
terminating in corresponding narrow radial air ports in the circular cylinder
face a¹ in combination with the slide valve E arranged to turn about a central
pin on the cylinder face and made with a series of narrow radial slots or openings
corresponding in number but differentiating with said air ports, the said slide
valve having a pin which engages with and is adapted to move up and down the
vertical slot g¹ of the guide bar G which is carried by parallel links H¹ H2 and
is connected to a treadle rod by moving which the guide bar will turn the slide
valve on the cylinder face and make any one of the slide valve slots open the
corresponding air port of the cylinder to the atmosphere whilst all the other air
ports are closed, thus enabling the quantity of air imprisoned under the piston in
the cylinder and the consequent stroke of the hammer or tup to be easily regulated
by the operator, the said parts being arranged and acting substantially as herein-
before described and illustrated by Figs. 8, 9, 10 and 11 of the accompanying
drawings.
5. In a pneumatic power hammer the employment of the air cylinder A made
with a series of air outlet holes one above the other at certain intervals apart
terminating in corresponding narrow horizontal air ports in a cylindrical cylinder
face, in combination with the cylindrical hollow slide valve E arranged to work
vertically on the cylinder face and made with a series of narrow horizontal slots
or openings corresponding in number but differentiating with said air ports, the said
slide valve being connected to the bell crank lever F which is carried by the cylinder
and engages with and is adapted to move up and down the vertical slot g₁ of the
guide bar G which is carried by parallel links H¹ H2 and is connected to a treadle
rod by moving which the guide bar will so act upon the bell crank lever as to
move the slide valve on the cylinder face and make any one of the slide valve
slots open the corresponding air port of the cylinder to the atmosphere whilst all
the other air ports are closed, thus enabling the quantity of air imprisoned under-

page_text: the piston in the cylinder and the consequent stroke of the hammer or tup to
be easily regulated by the operator, the said parts being arranged and acting sub-
stantially as hereinbefore described and illustrated by Figs. 12 and 13 of the
accompanying drawings.
Dated this 31st day of March 1898.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.