Improvements in the Valve Mechanism of Pneumatic Power Hammers.
Year: 1891

page_text: Date of Application, 20th June, 1891
Complete Specification Left, 9th Mar., 1892-Accepted, 9th Apr., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Valve Mechanism of Pneumatic Power
Hammers.
We ARTHUR WINKLER WILLS of Park Mills Nechells Birmingham in
the County of Warwick Edge Tool Manufacturer and JOSEPH EVANS of
No. 153 Nechells Park Road Birmingham aforesaid Manager of Works do
hereby declare the nature of this invention to be as follows :-
-
The said invention has reference to that class of pneumatic power hammers
in which the piston carrying the tup or hammer head works in a rising and
falling air cylinder which piston is cushioned at each end of its stroke; and the
said invention consists in the adaptation to or combination with the said pneumatic
power hammers of the automatic inlet and escape valves and mechanism connected
herewith hereinafter described whereby the working parts of the valves are
relieved from friction and wear during the greater part of the reciprocating
motion of the air cylinder and the blow of the hammer head regulated in a
simple and efficient manner. The inlet and escape valves which we use arc
ported trunnion valves and are automatically worked.
These valves are carried
by the air cylinder and consist of circular discs having ports in them at equi-
distant points opening into the air cylinder which ports by the motion of the
valve through a small angle can be made to coincide with or be cut off from
similarly arranged ports in the valve plate or body secured to the moving air
cylinder the ports in the said valve plate or body communicating with the external
air. These ported circular discs or valves are arranged one near the top of the
air cylinder and the other at a short distance below the middle of the air cylinder
the said valves being carried by parallel horizontal spindles trunnions on which
work in bearings in the valve plate. The bearing faces of the top and bottom
ported valves are pressed to and made to work air tight against the face of the
valve plate or body by means of lock nuts screwed on the ends of the valve
spindles external to the air cylinder.
The top and bottom valves are geared together by means of toothed sectors
on their parallel spindles the said spindles being so geared together and the
valves so arranged upon them that when the top valve is closed the bottom valve
is opened and the reverse. On the upper valve spindle is a projecting tappet
arm for operating the geared valves.
The opening and closing automatically of the two valves is effected as the air
cylinder makes its travelling motion in one or other direction by means of a
vertical regulating bar carrying stops or tappets which are situated in the path of
the tappet arm of the valve mechanism the said tappet arm when the air cylinder
nearly reaches the end of its upward stroke striking one of the stops or tappets and
when nearly reaching the end of its down stroke striking the other stop or tappet.
By the striking of the tappet arm against one or other of the stops or tappets on
the regulating bar a slight angular motion is given to the tappet arm and a corre-
sponding angular motion in opposite directions is given to the geared valves so as
simultaneously to open one valve and close the other valve for the cushioning
operation within the air cylinder as is well understood.
The regulating bar carrying the stops or tappets is connected to a hand or foot
lever and by operating on the said lever the position of the stops or tappets can be
adjusted to regulate the blow of the hammer head.
It will thus be understood that during the greater part of the stroke of the air
cylinder of the hammer the valves are unoperated upon and are thus relieved from

page_text: friction or wear excepting when it is necessary to reverse their position for the
cushioning operation as before described.
The stops or tappets instead of being secured to a regulating bar adjusted by a
hand or foot lever may be secured to a slide or other equivalent arrangement may
be used whereby the position of the stops or tappets may be adjusted according as
a light or heavy blow is required in the hammer.
Dated the 20th day of June 1891.
W. T. WHITEMAN,
Agent for the Applicants.
COMPLETE SPECIFICATION.
Improvements in the Valve Mechanism of Pneumatic Power
Hammers.
We, ARTHUR WINKLER WILLS of Park Mills Nechells, Birmingham, in
the County of Warwick Edge Tool Manufacturer and JOSEPH EVANS of
No. 153 Nechells Park Road, Birmingham aforesaid Manager of Works do
hereby declare the nature of the said invention and in what manner the same
is to be performed to be particularly described and ascertained in and by the
following statement:―
The said invention has reference to that class of pneumatic power hammers in
which the piston carrying the tup or hammer head works in a rising and falling air
cylinder which piston is cushioned at each end of its stroke; and the said invention
consists in the adaptation to or combination with the said pneumatic power
hammers of the automatic inlet and escape valves and mechanism connected there-
with hereinafter described, whereby the working parts of the valves are exposed to
little friction and wear and the blow of the hammer head regulated in a simple and
efficient manner.
The inlet and escape valves which we use are ported trunnion valves and are
automatically worked. These valves are carried by the air cylinder and consist of
circular discs having ports in them at equi-distant points opening into the air
cylinder, which ports by the motion of the valve through a small angle can be
made to coincide with or be cut off from similarly arranged ports in the valve
plate or body secured to the moving air cylinder, the ports in the said valve plate
or body communicating with the external air. These ported circular discs or
valves are arranged one near the top of the air cylinder and the other at a short
distance below the middle of the air cylinder, the said valves being carried by
parallel horizontal spindles, trunnions on which work in bearings in the valve plate.
The bearing faces of the top and botton ported valves are pressed to and made to
work air tight against the face of the valve plate or body by means of lock nuts
screwed on the ends of the valve spindles external to the air cylinder.
The top
and bottom valves are geared together by means of toothed sectors on their
parallel spindles, the said spindles being so geared together and the valves so
arranged upon them that when the top valve is closed the bottom valve is opened
and the reverse. On the upper valve spindle is a projecting tappet arm for
operating the geared valves.
The opening and closing automatically of the two valves is effected as the air
cylinder makes its travelling motion in one or other direction by means of a
vertical regulating bar carrying stops or tappets which are situated in the path of
the tappet arm of the valve mechanism, the said tappet arm when the air cylinder
nearly reaches the end of its upward stroke striking one of the stops or tappets and
when nearly reaching the end of its down stroke striking the other stop or tappet.
By the striking of the tappet arm against one or other of the stops or tappets on
the regulating bar, a slight angular motion is given to the tappet arm and a corre-
sponding angular motion in opposite directions is given to the geared valves so as

page_text: simultaneously to open one valve and close the other valve for the cushioning
operation within the air cylinder as is well understood.
The regulating bar carrying the stops or tappets is connected to a hand or foot
lever and by operating on the said lever the position of the stops or tappets can be
adjusted to regulate the blow of the hammer head.
We will now proceed to describe with reference to the accompanying drawings
the manner in which the said invention is to be performed.
Figure 1 represents in front elevation, partly in vertical section, and Figure 2 in
side elevation, partly in vertical section, a pneumatic power hammer to which valve
mechanism constructed according to this invention is applied.
Figure 3 represents in vertical section, partly in elevation and Figure 4 in front
elevation, drawn to a larger scale, the valve mechanism and regulating bar and
stops or tappets of the same; Figure 5 represents the same view of the valves as
Figure 3 excepting that their positions are changed; and Figure 6 represents a
horizontal section of the regulating bar and a portion of one of the stops or tappets
thereon.
In Figures 1, 2, 3 and 4 the valve mechanism is arranged for the hammer head
to deliver a light blow of the minimum strength and in Figure 5 the valve
mechanism is arranged for the hammer head to deliver a heavy blow of the
maximum strength.
The same letters of reference indicate the same parts in the several figures of the
drawings.
a is the reciprocating air cylinder of the pneumatic hammer worked from the
crank and connecting rod and crank shaft e in the usual way; d is the tup
or hammer head carried by the piston rod e and the piston working in the air
cylinder a.
It will seen by reference to Figure 1 that there is no mechanical connection or
gearing between the cylinder a and piston f; the cylinder and piston do not move
at the the same speed, the cylinder causing the piston to move by producing a
compression or expansion of air between either end of it and the piston as herein-
after described; g h are atmospheric valves near the top and bottom of the
cylinder. These valves constitute no part of this invention and have for their
object the admission of air into the cylinder above and below the piston when the
air within the said cylinder is of less pressure than that of the external atmosphere,
the said valves closing automatically when the pressure of air within the cylinder
exceeds that of the external air. As the functions of these valves are well known
we do not consider further explanation necessary.
In order that the action of the valve mechanism constituting this invention may
be the better understood we remark that the strength of the blow to be delivered
by the hammer head d is determined by the quantity of air compressed between the
bottom of the cylinder and the falling piston and the quantity of air compressed
between the top of the piston and cover of the cylinder so that by opening wholly
or partially one of the valves and closing wholly or partially the other valve, the
quantity of air to be compressed by the rising and falling piston can be regulated
and the strength of the blow changed as hereinafter particularly described. This
is effected by the use of the valve mechanism and appliances constituting this
invention which we will now proceed to describe in detail.
i, are two ported circular valves carried by the air cylinder for permitting of
the entrance of air into and the escape of air from the said cylinder. The ported
valve is situated near the top of the air cylinder a and the other valve k near the
middle of the air cylinder, the said valves being supported by the valve plate
secured to the air cylinder. The construction and action of the air inlet and
escape valves i, k will be best understood by referring to the enlarged views
Figures 3, 4 and 5.
The ports in the valves i and k are marked respectively and and the ports
in the valve plate are marked respectively 12, 13, the said ports 12, 13 opening to
the external air.

page_text: By moving the valves & through a small angle they can be made to open wholly or
partially the ports 12, and thereby permit air to enter and escape from the
cylinder (see the open top ports and the closed bottom ports in Figures 3 and 4).
The said valves i, are made solid with the parallel horizontal spindles, and
trunnions m, m on the said spindles work in the hollow bearings n, n in the valve
plate 1.
The bearing faces of the top and bottom valves i, kare pressed to and made to
work air tight against the face of the valve plate by the lock nuts at screwed
on the ends of the valve spindles as seen in Figure 3. The two ported valves i, k
are geared together by means of the toothed sectors p. 7 on the parallel
spindles, of the said valves. It will be seen by an examination of the
drawings that the two valve spindles are so geared together and the ported valves so
arranged upon them that when the top valve is opened the bottom valve kis
closed and the reverse. On the upper valve spindle is a projecting tappet arm
for operating the geared valves.
On the side of the hammer frame is a regulating vertical bars sliding in guides
on the said hammer frame. This regulating bars carries two horizontal stops or
tappets which are situated in the path of the tappet arm on the top valve of
the geared valves. It is by the action of one or other of these stops t, on the
tappet arin that the positions of the geared valves can be so changed as to
regulate the blow of the hammer head. The movable stops or tappets, on the
sliding regulating bars are fixed at the required height on it and at the required
distance apart by the clamping plates and nuts at 2 (see Figure 6). The
height of the sliding bar s carrying the stops or tappets t, is adjusted to regulate
the blow of the hammer head by means of the hand lever a (or other lever) which
is fixed, after the bars has been adjusted, in the quadrant by a clamping screw
or otherwise. When the regulating bars is adjusted in one position, the stop or
tappet can be made to operate during the upward motion of the reciprocating
cylinder on the geared valves i. k through the tappet arm r, and when the
regulating bar is adjusted in another position the other stop or tappet a can be
made to operate during the downward stroke of the cylinder, on the tappet arm r
and reverse the positions of the said valves i, k.
A
In the hammer represented in Figures 1 and 2 and in the enlarged views of the
valve mechanism represented in Figures 3 and 4 the regulating bar s has been so
adjusted that the tappet arm of the geared valves has struck the top stop or
tappet t on the upward motion of the cylinder a, thereby fully opening the top
valve and fully closing the bottom valve k; that is, the turning down of the
tappet arm r, by striking against the temporarily fixed stop or tappett, has
moved the ported valve i through such an angle as to make its ports coincide with
those in the valve plate ; at the same time the other valve & has been moved,
through the gearing p, q, in an opposite direction so that its ports do not coincide
with those in the valve plate as represented. When the valves are so arranged
the minimum quantity of air between the cover of the cylinder and the top of the
piston is obtained for cushioning on the ascent of the cylinder and piston, and for
giving the least initial velocity to the piston on the descent of the cylinder and the
maximum quantity of air in compression is obtained between the bottom of the
cylinder and the underside of the piston by the compression of which maximum
quantity of air on the downward motion of the cylinder and piston the said piston
is arrested or cushioned and the hammer head thereby made to give its lightest or
minimum blow. On the ascent of the cylinder the piston has the required
upward velocity given to it by the expansion of the air between its bottom and
the underside of the piston. As the hammer works, the reciprocating cylinder a
carries the tappet arm between the two stops t, u, which are temporarily
inoperative; that is, as the cylinder a rises the tappet arm just reaches but is
not operated by, the top stop t and as the cylinder descends the tappet arm does
not reach the bottom stop u. The two valves ik are thus maintained in the
relative positions represented in Figures 1, 2, 3 and 4 so long as the hammer head
2"

page_text: is required to give the blow for which the regulating bars has been adjusted.
When it is desired to change the blow delivered by the hammer head, from a
light to a heavy blow, the regulating bars is raised by the hand lever so as to
bring into operation the lower stop or tappet and take out of action the upper
stop or tappet t. When the cylinder a now makes its descending stroke the tappet
arm strikes the now operating lower stop or tappet and the said tappet arm is
lifted into the position represented in Figure. By this lifting of the tappet
arm the top valve is fully closed and the bottom valve is fully opened as
represented in Figure 5, the said valves remaining in those positions till the
position of the regulating bars is again changed.
By the changed positions of the two valves, last described and represented
in Figure 5 the maximum quantity of air in compression between the cover of the
cylinder and upper side of the piston for cushioning on the ascent of the cylinder
and for giving the greatest initial velocity to the piston on the descent of the
cylinder, is obtained. The quantity of air between the bottom of the cylinder
and the underside of the piston is at the same time diminished so as to offer the
least resistance to the downward motion of the piston and the hammer head is
consequently made to deliver its heaviest or maximum blow.
By raising the regulating bar and its stops to the required position so as to
cause them to act on the tappet arm and partially open both of the valves i, ka
blow of the desired intensity may be delivered by the hammer head.
It will thus be understood that during the working of the hammer the ported
valves are not operated upon and are thus relieved from friction or wear, the
valves only being moved when it is necessary to reverse or alter their positions for
the cushioning operation.
The stops or tappets instead of being secured to a regulating bar adjusted by a
hand or foot lever, may be secured to a slide, or other equivalent arrangement
whereby the positions of the stops or tappets may be adjusted according as a
light or heavy blow is required in the hammer.
Having now particularly described and ascertained the nature of the said inven-
tion and the manner in which the same is to be performed we declare that what
we claim as the said invention of Improvements in the valve mechanism of
pneumatic power hammers :-
:-
First The combination with the reciprocating air cylinders of pneumatic
power hammers, for the purpose of regulating the blow delivered by the tup or
hammer head, of two ported inlet and escape valves and correspondingly arranged
ports in the valve plate communicating with the external air, the said ported
valves being so arranged on parallel spindles and geared together that when one of
the said valves, is wholly closed or partially closed, the other valve is simul-
taneously wholly opened or partially opened for admitting air to and permitting of
the escape of air from the reciprocating cylinder of the hammer, the several parts
being arranged and operating substantially as herein before described and
illustrated in the accompanying drawings.
Secondly-The combination with the said ported valves and appliances, of a
vertical sliding bar or a slide carrying stops or tappets situated in the path of a
tappet arm on the spindle of one of the ported valves, the striking of the tappet
arm against one or other of the stops or tappets operating the ported valves in
the manner described and thereby regulating the blow delivered by the hammer
head substantially as herein before described and illustrated in the accompanying
drawings.
Dated the Twenty-third day of February 1892.
ARTHUR WINKLER WILLS.
JOSEPH EVANS.