IMPROVEMENTS IN ATMOSPHERIC HAMMERS
Year: 1876

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention of
"IMPROVEMENTS IN ATMOSPHERIC HAMMERS." A communication from abroad
by John Cooledge Butterfield, of Chicago, Illinois, United States of America.
Scaled the 11th August 1876, and dated the 7th June 1876.
Scaled the 11th August 1876, and dated the 7th June 1876.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 7th June 1876.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN ATMOSPHERIC HAMMERS."
A communication.
Atmospheric hammers have heretofore been constructed, and their characteristics
may be classed as follows, namely:-The employment of atmospheric pressure added
to the weight of the hammer to increase the impact, the expansion of compressed
air to increase the impact compression above and below the piston, the former to
elevate the hammer and the latter to increase the impact, also regulating the force
of the blow by air cushioning and elevating the hammer by mechanism and by
compressed air.
For the purpose of clearly explaining this Invention I will point out the material
differences between it and the atmospheric haminers heretofore made.
An important desideratum in hammers of this class is to intercept the shock of
the hammer blow so that it shall not be transmitted to the frame of the machine.
In one of the hammers alluded to above this object is accomplished by the inter-
position of a body of air between the hammer and its motive mechanism, but
shocks are, nevertheless, transmitted through the close packings required to prevent
the escape of air under pressure. In my hammer the transmission of shocks is
prevented by the interposition of cushions of an elastic solid body like india-rubber
or other suitable substance. The hammers above alluded to have their air cylinders
in line with the hammer, and the power required is sufficient to lift said hammers
as dead weight. My hammer is counterbalanced, and therefore moved with a
minimum expense of power. The aforesaid hammers are designed only to cushion
in one direction, and can only control the force of the blow with variations of the
rapidity of delivery. My hammer cushions in either or both directions, and the
force of the blow can be controlled irrespective of the rapidity of delivery. It
Price 6d1

page_text: will therefore be perceived that I do not employ air springs for the purpose of
intercepting a shock,, but solely for the purpose of operating and controlling the
action of the hammer.
My Invention comprises, first, a balanced atmospheric or air spring hammer;
second, a supplemental air cylinder capable of cushioning in either or both directions
and to any desired extent; third, a tightener, treadle, and brake; fourth, a cast
metal hammer beam. Also various details of construction hereafter specified.
The main elements of this Invention are as follows, that is to say, a hammer
moving in upright guides and attached to one end of a hammer beam mounted
on journals about midway of its length, combined with an air cylinder attached
to. the opposite end of the said beam, and a piston in said cylinder actuated by an
excentric or crank rod. Also the oscillating hammer beam mounted upon journals
about midway of its length, and attached to the opposite ends of the same, in
combination with an air cylinder, the piston whereof is actuated by a crank or
excentric combined with a supplemental cylinder with an adjustable valve near
its upper end, and its piston rod joined to said beam between its fulcrum and the
haminer, for the purpose of arresting the upward thrust of said hammer. The
supplemental air cylinder is also provided with an adjustable valve near its lower
end for the purpose of cushioning the downward blow of the hammer to regulate
the impact thereof without affecting the speed of delivery. The said air cylinder
is provided with a piston whose length is nearly equal to the length of its stroke.
The aforesaid treadle is provided with a rack combined with the tightener arm
which has a rack for operating the said tightener, and there is a laterally projecting
shoe adapted to enter within the rim of a pulley and act as a brake thereon. The
hammer beam is constructed of cast metal with a central longitudinal web, flanges,
and angular truss ribs. Intercepting cushions are placed between the cross head
and cups or seats to allow the laminer to have an easy movement and to avoid
the concussion and shocks which the hammer would otherwise have, and prevent
the hammer rod from wholly resisting the rebound of the hammer. These cushions
I prefer to make of solid india-rubber, with vertical holes through them to receive
a piston rod, which is provided with a screw to receive a tightening nut to hold
the said rubber cushions between the seats and cross head at a proper tension.
I also use an adjustable excentric slotted in its central part and placed on a shaft,
the object of the slot being to give a greater or less throw to the excentric. The
means for holding the excentric in place when adjusted consist of a nut turned on
the shaft and a set screw put through a slot in a collar or plate, by means of
which the adjustment is made permanent.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the 5th
December 1876.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, and Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN ATMOSPHERIC HAMMERS."
A communication from abroad by John Cooledge Butterfield, of Chicago, Illinois,
United States of America.
Atmospheric hammers have heretofore been constructed, and their characteristics
may be classed as follows, namely:-First, atmospheric pressure added to the
weight of the haminer to increase the impact; second, expansion of compressed air
to increase the impact; third, compression above and below the piston, the former
to elevate the hammer and the latter to increase the impact. In the first and
third cases it has been proposed to regulate the force of the blow by air cushioning;
the first and second elevate the hammer by mechanism; the third elevates it by
compressed air.
For the purpose of clearly explaining my Invention I will point out the material
differences between it and the atmospheric hammers heretofore made.

page_text: A principal desideratum in hammers of this class is to intercept the shock of the
hammer blow so that it shall not be transmitted to the frame of the machine. In
the aforesaid third hammer this is accomplished by the interposition of a body of
air between the hammer and its motive mechanism, but the shock is, nevertheless,
transmitted through the closed packings required to prevent the escape of air
under pressure. In my machine the transmission of shocks is prevented by the
interposition of cushions of an elastic solid material, such as india-rubber.
The aforesaid haminers have their air cylinders in line with the hammer, and the
power required is suflicient to lift said hammers as dead weight. My hammer is
counterbalanced, and therefore moved with a minimum expenditure of power. The
aforesaid hammers cushion in one direction, and can only control the force of the
blow with variations of the rapidity of delivery. My hammer cushions in either
or both directions, and the force of the blow can be controlled perfectly irrespective
of the rapidity of delivery. From the above statement it will be perceived that I
do not employ air springs for the purpose of intercepting a shock, but solely for
the purpose of operating and controlling the action of the haminer, as will more
fully appear in the following description.
My Invention comprises, first, a balanced atmospheric or air spring hammer;
secondly, a supplemental air cylinder capable of cushioning in either or both
directions and to any desired extent; thirdly, a tightener, treadle, and brake; and,
fourthly, a cast metal hammer beam.
Figure 1 is a side elevation of an atmospheric hammer constructed according to
this Invention. Figure 2 is a sectional elevation of the principal air cylinder of
the same.
Figure 3 is a sectional elevation of the supplemental air cylinder.
Figure 4 is a side elevation of the treadle and tightener. Figure 5 is a front
elevation, partly in section, of the said tightener.
Figures 6, 7, 8, and 9, shew details of the excentrics.
Figure 10 is a side elevation of the hammer beam. Figure 11 is a plan of the
same.
Figures 12 and 13 are front and edge elevations of the hammer and hammer rod.
The leading elements of this Invention are, a hammer A moving in upright
guides; a horizontal oscillating hammer beam B mounted on journals about midway
of its length; an air cylinder C attached to the said beam at the end opposite the
hammer; and a piston D in the said cylinder operated by the crank or excentric
rod E. The intercepting cushions F¹ placed between the cross head F, Figures 12
and 13, and cups or scats 3, 3, allow the hammer to have an easy movement and
avoid the concussion and shock which a hammer would otherwise have, and prevent
the hammer rod from wholly resisting the rebound of the hammer. These cushions
I prefer to make of solid india-rubbber with vertical holes through them to receive
a piston rod 4, which is provided with a screw to receive a tightening nut to hold
the said rubber cushions between the seats 3, 3, and cross head F at a proper
tension.
in
Figures 6, 7, 8, 9, shew the construction of an adjustable excentric, Figures 8 and 9
being a side and edge elevation thereof. This excentric is slotted in its central part
and is placed on a shaft H, the object of the slot being to give a greater or less
throw to the excentric. The means for holding the excentric in place when adjusted
consists of a nut 5 turned on the shaft H and a set screw 6 put through a slot
the collar or plate 7, by means of which the adjustment is made permanent. The
two slots perimit the excentric J to have such a throw as to give to the piston rod E,
Figure 1, any desired length of stroke. The collar 7 is shrunk fast to the shaft E,
or is to be otherwise tightly secured. The frame G which supports all of the
working parts of this hammer has at its top boxes g one on either side for the
reception of the journals b, b, of the hammer beam B. The guide frame a and

page_text: anvil block caro upon the front side of said frame, and two arms & project from the
rear side near the base to support the boxes in which the crank shaft E revolves.
The hammer rod e is joined to the front end of the beam B by a wrist pin and to
the cross head F by forked connections; the said pin is driven transversely through
the end of said beam. At the rear end the hammer beam B is expanded and formos
a circular loop having centre screws i in its opposite sides and transversely to the
beam whereon the oscillating cylinder C is suspended. The piston D works in the
cylinder C, and its piston rod E is coupled to the crank or excentric rod, which
is actuated by the excentrics J. The cylinder C is closed at each end and has a
vent hole in its side about midway of its length. Power is transmitted to the
pulley K on the shaft H by a belt in the usual manner. It will be perceived
that I have a horizontal oscillating hammer beam with its fulcrum about midway
of its length. From the front end of this beam the hammer A is suspended, and
the cylinder C is attached to its rear end. This cylinder and its attachments
are constructed to equal in weight the hammer A and its attachments, so that
said hammer and its working connections are balanced upon the hammer beam
journals b, and to move the said hammer requires only sufficient power to overcome
the inertia and friction of the parts, whereas with all atmospheric hammers hereto-
fore used the required power must be sufficient not only to overcome the inertia
and friction but to raise the dead weight of the hammer in addition. These
hammers therefore require a maximum power while mine requires only the minimum.
When the piston D descends the compression of the air in the bottom of the
cylinder C begins as soon as said piston passes the vent k, and said cylinder will
begin to descend and the hammer will begin to rise as soon as the compression is
sufficient to overcome the inertia and friction of the moving parts. When the
movement of the piston is reversed, expansion of the compressed air and momentum
will cause a slight continuance of the upward motion of the hammer, but this
action will be quickly checked by compression of the air in the top of the cylinder C
as the piston D moves upward, and the hammer will thereby be driven downward
upon the anvil, the intensity of the impact being proportionate to the rapidity of
the reciprocation of the piston. As the excentric or crank passes its lower centre
the weight of the piston D, with its rod E and attachments, is sustained by the
compressed air in the bottom of the cylinder C, and therefore the excentric is
entirely relieved of thrust in reversing the motion of said piston and rod. The
same effect in a reverso direction takes place as the excentric passes its upper centre.
The above-described operation is effective, but is accompanied by one disadvantage,
namely, an upward thrust upon the bearing b occasioned by the continued upward
movement of the hammer as above mentioned, and this effect is counteracted by
the second part of my Invention, which relates to a supplemental air cylinder L
whose piston rod is jointed to the hammer beam B by the centre screws m in
front of the fulcrum 6. The cylinder L is so mounted upon centre screws n that
it is capable of the required oscillation as the beam B moves upon its fulcrum.
The cylinder L is smaller in calibre than the cylinder C. As its piston is moved
from end to end in the cylinder L its effect is in opposition to cylinder C as follows:
-When the cylinder Ċ descends under the force of the compressed air in the
bottom of said cylinder, the piston P is drawn to the top of the cylinder L, and
the tension of the compressed air therein is opposed to the downward movement
of the said cylinder ; but this effect may be so graduated as to equal only
the power necessary to overcome the upward thrust of the hammer, and then by
the expansion or reaction of the air compressed in the top of the cylinder L to
impart to the hammer its initial downward movement. By the proper graduation
of these opposing forces all upward thrusts of the journals b against the caps of the
boxes gmay be prevented, and the operation of the hammer beam will be unaccom-
panied by any jarring or shocks. The required control of the resistance in the
cylinder L is obtained by means of the valve p, which enables the attendant to 5
regulate the amount of air cushioning by adjusting said valve to permit a greater
or lesser escape of the compressed air. The piston D passes the vent at mid-

page_text: stroke; but it is necessary that the piston P in the cylinder L shall cut off its
vent q almost as soon as the movement of said piston commences. Therefore it
is possible to secure about double the compression in the cylinder L as compared
with the cylinder C, and a corresponding ease and delicacy of adjustment at the
valve
2). I therefore make said piston P very long, nearly equal to half the length
of said cylinder L, and provide two vents so that air may enter both top and
bottom ends of said cylinder. In atmospheric hammers heretofore used the force
of the blow could only be controlled by regulating the speed of the hammer. But
it is of considerable importance to control the blow without varying the speed.
This result is readily effected by means of a valve at the bottom of the cylinder L.
When this valve is closed the air compressed under the piston P takes up the force
of the hammer stroke downward, and without in any degree affecting the speed,
and this effect may be graduated at will by adjusting said valve to permit an
escape of a greater or less portion of the confined air. The aforesaid nachine is
provided with the usual treadle S and tightener T, whereby the speed may be
regulated in the common manner. The treadle connection, however, is peculiar,
that is to say, the treadle S has its fulcrum upon pins & driven into the sides of
the frame G near its base, and extends to the rear of said fulcrum pins. On one
side it is provided with a counterweight, and on the other it is provided with
a segment rack which meshes into a similar segment rack u on the front end of
the tightener arın U, which is journalled at its rear end upon a pin v driven into
the extremity of the arm & on the same side of the frame with the pulley K. A
projecting shoe w on the side of the tightener arm U enters within the rim of the
pulley K and acts as a brake thereon when the tightener falls down out of action
to stop the motion of the driving shaft H. The hammer beam B requires sufficient
strength and stiffness to move the hammer with the requisite speed, and at the
same time it is desirable to reduce its weight as much as may be compatible with
the requisite rigidity. I have therefore devised a cast-metal trussed beam, which
has been found to answer this purpose. The said beam B consists of a web a with
top and bottom flanges y and angular ribs or trusses extending from end to end
as shewn. The web x is in the centre longitudinally, and the flanges y and ribs.
are arranged on each side of said web. This beam is cast in a single piece.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim
First. A hammer attached to one end of a hammer beam mounted on journals
about midway of its length combined with an air cylinder attached to the opposite
end of the said beam and a piston in said cylinder actuated by an excentric or
crank rod operating in the manner and for the purpose set forth.
Second. An oscillating hammer beam mounted upon journals about midway of its
length and attached to the opposite ends of the same a hammer and an air
cylinder whose piston is actuated by a crank or excentric combined with a supple-
mental cylinder with an adjustable valve near its upper end, and its piston rod
joined to said beam between its fulcrum and the hammer for the purpose of
arresting the upward thrust of said hammer, as above set forth.
Third. An oscillating bammer beam mounted upon journals about midway of its
length and attached to opposite ends of the same a hammer and an air cylinder
whose piston is actuated by a crank or excentric combined with a supplemental air
cylinder provided with an adjustable valve near its lower end for the purpose of
cushioning the downward blow of the hammer to regulate the impact thereof
without affecting the speed of the delivery.
Fourth. The air cylinder provided with adjustable valves near its upper and
lower ends, and with a piston in length nearly equal to the length of stroke com-
bined with a hammer and its operative mechanism for the purpose specified.
Fifth. The treadle provided with a rack combined with the tightener arm also
rovided with a rack for the purpose of operating the said tightener, as above set
forth.

page_text: Sixth. The combination of the tightener arm and the laterally projecting shoe
adapted to enter within the rim of the pulley and act as a brake thereon, as above
set forth.
Seventh. A hammer beam constructed of cast metal with a central longitudinal
web, flanges, and angular truss ribs, as above set forth and for the purposes
specified.
Eighth. The combination of the india-rubber cushions, the scats, and the cross-
head, as above described and for the purpose specified.
Ninth. The combination of the forked hammer rod, the beam, the cross head, the
cushions, and the seats, as above set forth and for the purpose specified.
Tenth. The slotted excentric in combination with the shaft, the plate or collar,
the nut, and the set screw, and with the piston, as above set forth and for the
purpose specified.
Eleventh. An atmospheric hammer with its parts constructed and combined as
shown in Figure 1, and the other Figures of the Drawing, and operating as above
set forth.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and scal, this Fifth day of December, in the year of our Lord One
thousand eight hundred and seventy-six.