IMPROVEMENTS IN MACHINERY FOR COMPRESSING AND SOLIDIFYING BLOCKS OF CONCRETE AND OTHER MATERIALS, BENDING SHEET METAL, AND FOR SIMILAR PURPOSES
Year: 1878

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 MACHINERY FOR COMPRESSING AND SOLIDIFYING BLOCKS
OF CONCRETE AND OTHER MATERIALS, BENDING SHEET METAL, AND FOR SIMILAR
PURPOSES." A communication from abroad by Augustus Frederick Nagle, of
Providence, Rhode Island, United States of America,
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 3rd June 1878.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent
Agents, Southampton Buildings, London. "IMPROVEMENTS IN MACHINERY FOR
COMPRESSING AND SOLIDIFYING BLOCKS OF CONCRETE AND OTHER MATERIALS,
BENDING SHEET METAL, AND FOR SIMILAR PURPOSES." A communication from
abroad by Augustus Frederick Nagle, of Providence, Rhode Island, United States
of America.
These improvements relate to that class of presses containing dies or moulds with
which a plunger co-operates for subjecting matter to heavy compression, either for
the purpose of solidification, or for imparting to such matter a form corresponding
to that of the die or mould. For the accomplishment of both purposes I have
embodied the several features of this Invention in a press particularly designed to
mould and compress asphaltic concrete paving blocks.
My improvements are in part applicable however to presses for other purposes, as,
for instance, the bending or forming of sheet metal useful in the manufacture of
metallic goods of various kinds, and they are equally useful in many other processes
where rapidity in execution, high pressure, and economy in operation are of special
importance.
In the manufacture of compressed concrete paving blocks it is more important
that the blocks should be practically uniform in density than that they should have
the same exact dimensions. The moulds in all cases arbitrarily secure uniform

page_text: length and breadth to blocks formed therein, but it is obvious that if the thickness
be uniform, the density will vary in proportion as the mould is wholly or partially
filled with concrete prior to compression. It is also obvious that in a press which
has its plunger operated for compression by a cam or other positive mechanical device,
uniformity in the density of the compressed material is only possible when the
mould is filled each time with accuracy, and this is practically impossible, owing to
the semi-plastic condition of the concrete.
The prime object of this Invention is to secure uniform compression regardless of
the quantity of material in the mould, and to that end the said Invention consists
mainly in the combination with a suitable die or mould of a plunger fitted to the
mould, a piston, a piston rod, a steam cylinder, and an automatic valve for succes-
sively admitting steam to and exhausting it from the cylinder at the rear of the
piston. In a press embodying these elements in combination the plunger will
compress with a power equal to the aggregate steam pressure on the piston, less the
power requisite to overcome the weight of the parts moved and their friction, and
the pressure is the same on the contents of the mould whether it be properly filled
or not.
For properly controlling the piston and plunger while under steam pressure, the
said Invention further consists in the combination with the mould, the plunger, the
piston and its rod, of a steam cylinder, provided with a steam and exhaust port at
one end thereof, and a port or passage at its opposite end for the escape and
admission of air (or exhaust steam, as the case may be) from and to the cylinder in
front of the piston, and a valve or valves for automatically controlling the said
passages. The aforesaid valve or valves must be so operated, and so constructed
and arranged with reference to the cylinder ports, that when live steam is first
admitted to the cylinder at the rear of the piston the passage or port at the front
end is wholly closed, thus cushioning the piston, and obviating or preventing such
shocks as would otherwise be incident to its movement. After the cushioning of
the piston the front port is partially uncovered, permitting the air to escape, and
thereby allowing the piston to advance and exert its full power through the plunger
upon the material in the mould. Then the rear port is closed to steam and opened
to exhaust, the front port remaining open to allow the admission of air or exhaust
steam in front of the piston, which is then with the plunger free to move to its
normal position.
I prefer that the press should be upright, in order that the return of the piston
and the withdrawal of the plunger in the mould may be effected by gravity.
The mould employed for the purpose of this Invention is one which has a
moveable top or head block, and is therefore open at both ends, the top or upper
end of the plunger serving as the bottom of the mould. During the movement of
the head block in opening the mould, it is obvious that the pressure on the contents
of the mould should not be continued, and therefore the steam pressure is wholly
removed from the piston, and the plunger is allowed to drop, thus freeing itself from
the concrete block, which is thereafter ejected from the mould by a second forward
movement of the plunger, and for accomplishing this object my Invention further
consists in the combination with a mould, a sliding head block, a plunger, piston
rod, piston, steam cylinder, and valve, of a continuously driven lifting device, which
at proper intervals forces up the plunger for ejecting the contents of the mould.
I prefer a cam on a continuously driven shaft, and a piston rod which carries the
plunger on its upper end, and extends downward through the lower head of the
cylinder for contact with the cam, but other well-known mechanical devices may be
successfully employed.
The more or less plastic character of asphaltic concrete renders it difficult to
properly charge a mould, but this charging is greatly facilitated by another feature
of my Invention, which consists in the combination with a mould of a vertical
hopper or chute, which is smaller at its upper end than at the lower end, so that
concrete supplied thereto passes in a mass readily downward into the mould without
clogging or wedging,

page_text: It is desirable that the lower end of the chute or hopper should be somewhat
smaller than the mould, so that the concrete will have no corner or edges to engage
with in its downward movement.
I prefer also for lessening the liability of wedging that the corners of the chute
should be rounded instead of rectangular.
In order to secure a complete closure of the mould by a sliding head block, the
said Invention further consists in the combination with a mould, provided with a
hardened cutting edge on one side at its top, of a sliding head block provided with
a similar cutting edge for shearing or cutting through particles of rock and asphalt
interposed between the cutting edges during the closing movement of the said head
block.
For preventing the blocks from unduly adhering to the mould, and for keeping
the latter smooth and clean, the said Invention further consists in the combination
with the mould and plunger of a reservoir connected with the plunger by suitable
ducts or pipes, whereby oil or other lubricating matter may be distributed upon the
interior surfaces of the mould during the movements of the plunger therein.
As the top or end of the plunger forms the bottom of the mould, and as it is
desirable that the press should be capable of making blocks of various sizes, this.
Invention further consists in the combination with the mould and its movable head
block of a plunger which is adjustable with reference to the mould, so that it
may be permitted to fall more or less, according to the thickness of the blocks
required.
For relieving the shock otherwise incident to the fall of the plunger and piston,
the said Invention further consists in the combination with the plunger rod and
piston of a head on the piston rod beneath the plunger, and a chamber to which
the head is accurately fitted, so that when the plunger falls the head enters the said
chamber, and is cushioned by the air therein.
In the accompanying Drawings,-
Figure 1 is a side elevation of a press embodying the several features of my
Invention, as arranged for the manufacture of concrete paving blocks.
Figure 2 represents the same press partly in central lateral vertical section, and
with the front main columns of its frame removed.
Figures 3 and 4 represent in side elevation and central vertical section the valves
and valve chamber and its connections.
Figure 5 represents in horizontal section the piston of the said steam valve.
Figure 6 illustrates the shape of the valve cam.
Figure 7 represents in vertical section the sliding hopper, the head block, and
mould filled with concrete and closed ready to receive pressure.
Figure 8 is a similar view showing the mould open, and the compressed block
ready to be discharged.
Figure 9 represents a portion of the inould and the plunger partly in section to
illustrate the manner of lubricating the mould.
Figure 10 is a side view of the cams mounted on a shaft.
Figure 11 represents the plunger in horizontal section, and shews the arrangement
of interior lubricating (lucts.
A denotes the steam cylinder, which is incorporated with and forms part of the
frame of the press. It is supported on four columns a¹ mounted on a base plate a.
The cap plate a² of the press is above the cylinder, and is firmly connected thereto
and supported by four heavy iron rods or bolts a³. The mould is centrally located
in the cap plate, and may be of any desired form.
For making asphaltic concrete paving blocks it is desirable that the mould be
lined with steel plates a secured by bolts, as shown in Figure 2, and this steel
lined mould constitutes one portion of my Invention.
The said cap plate on each side is provided with two heavy upright flanges, one
on each side, which are channelled from front to rear, as shown at a, Figures 7
and 8, for the reception of laterally projecting portions of the sliding hopper B,
and its head block b. The interior of the hopper is clearly shown in Figures 2, 7,

page_text: and 8. It has interior rounded corners, is smaller at the top than at the bottom, and
is somewhat smaller at its lower end than the area of the mould C, so that the
more or less plastic mass of concrete will readily pass downward into and fill the
mould. The head block b is clad on its lower face with a hardened steel plate b¹,
which is in sliding contact with the upper surface of the cap plate a². The head
block plate has a shear or 'cutting edge, which co-operates with a corresponding
hardened edge of the steel lining of the mould, in order that small fragments of
rock may not obstruct the movement of the sliding block enclosing the mould, said
fragments being readily disposed of by the cutting edges.
A pan is mounted on the hopper to serve as a receptacle for concrete, and from
which the hopper and mould is supplied from time to time by an attendant, it being
advisable that the said hopper should at all times contain considerably more concrete
than is requisite for filling the mould. This hopper is connected by a link b² to a
vertical lever b³, which is pivotted on the frame near the cylinder, and is furcated at
its lower end.
Each leg of the lever 63 is connected by double links b* to rockers 65 pivotted to
the bed plate a.
One of these rockers is located in front, and the other at the rear
of the shaft D, and each is provided with a friction roller 68, clearly shewn in
Figures 1, 2, and 10. One of these double links b is composed of oval counter-
parts, with the central portions thereof removed to afford space for the shaft D,
which carries the two cams d, shown in Figures 2 and 10.
These cams are 80
shaped and so set on the shaft with reference to each other that the lever b³ is
positively vibrated, and the sliding hopper moved to and fro at certain intervals, as
hereafter described.
The shaft D also carries a cam d', which is located beneath and in line with the
centre of the steam cylinder, and is the mechanical lifting device by means of which
the compressed contents of the mould are ejected.. At the outer end of the shaft D
is a valve cam d³, which is relied upon to impart certain movements to the valves
of the press. The cam is cut in the side of a circular plate, and is a continuous
groove of a form which is illustrated on an enlarged scale in Figure 6, and also fully
shown in Figure 10.
The plunger E is so fitted to the mould that it may move freely and securely
therein in close contact with the sides of the same. For lubricating the interior of
the mould, thus keeping it smooth and permitting the blocks to be easily ejected,
an oil reservoir e is attached to the press at a point above the mould, and con-
nected with the plunger by a jointed or flexible pipe e¹, which communicates with
a central vertical duct e² and other horizontal ducts within the plunger, through
which oil or other lubricant is discharged, preferably into a mass of fibrous
absorbent which is kept in place around the plunger by perforated springs e*,
one of which is shown in Figure 9. The contact of these springs with the sides
of the mould secures a proper distribution of the lubricant. The sectional view of
the plunger, Figure 11, shows the arrangement of the ducts.
The plunger is firmly mounted upon the upper end of the piston rod F, and it is
preferably arranged so that when at its lowest position it will still be within the
mould, in order that it may always be guided therein, and because when so arranged
the plunger and mould may be more accurately fitted to each other than would be
possible if the plunger at each stroke was permitted to leave the mould. The
piston rod F is preferably extended downward through the lower or rear head of
the cylinder; its lower end can then be placed in direct communication with the
ejecting cam d, but instead of having the piston rod thus extended it may terminate
at the piston G, and the ejecting cam may be arranged to co-operate with a lever
connected by a link to an upper lever in turn connected with the piston rod and
plunger; but this latter arrangement would involve complication with no more
satisfactory results.
The piston G is strong and heavy, is secured to the rod F, and properly packed
with relation to the cylinder, and each head of the latter is provided with a stuffing
box for the piston rod.

page_text: H denotes a cylindrical valve chamber, which communicates by the port f with
the lower or rear end of the cylinder, and by the port g with the upper or front
end of the same. The steam pipe h communicates with the lower end of the valve
chamber, and the exhaust pipe i communicates with the central portion thereof.
The valve is of peculiar construction, and is in fact two valves mounted on a
valve rod k, which is provided with a stuffing box in each head of the chamber;
this valve has two pistons; the lower one controls the cylinder port f for admitting
and exhausting steam; it is hollow and webbed, and has apertures l¹, which admit
steam within it, and thence the steam by an annular space surrounding the valve
rod passes to the upper portion of the chamber, thus balancing the valve against
steam pressure. The upper valve piston m is solid, but has a wide flange supported
by radial webs m¹. The flange is cut away at m² beneath the upper valve piston
head for affording a communicating passage by the port g between the front or upper
end of the cylinder and the central portion of the valve chamber.
It is to be understood that the upper valve piston is relied upon to properly
guard the port g, so that the upward movement of the cylinder piston G under
steam pressure may be properly controlled, and all undue shocks may be obviated
by maintaining a cushion of air or exhaust steam above the piston as long as may
be necessary, and then permitting the compressed air to slowly escape while the
piston and plunger are completing their upward movement.
The lower end of the rod k is provided with a slide k¹ and a friction roller k²
mounted on a stud projecting from the slide, so that the roller occupies the cam
groove in the cam da on the outer end of shaft D. Above the cylinder, and
mounted thereon, is a yoke frame n with a screw-threaded eye which encloses the
piston rod. A hand wheel o, with a screw-threaded neck, is fitted to the yoke, so
that by turning the wheel it may be raised or lowered on the screw thread. The
upper surface of the wheel is centrally recessed, as at o¹, forming a chamber which
is accurately fitted to receive the circular head or plate o² on the bottom of the
plunger E, so that when the plunger falls an air cushion is afforded in the chamber
to obviate the undue shock which would otherwise be liable to occur when the
plunger falls.
By turning the hand wheel up or down the drop of the plunger may be varied,
thereby decreasing or increasing the cubic capacity of the mould. A guide is
afforded for the lower end of the piston rod by a yoke p, which is secured to the
lower head of the cylinder. In discharging a block from the mould an easy contact
is afforded between the cam d¹ and the piston rod by a friction roller at the lower
end of the rod.
The operation of this improved press is as follows:-It will be assumed that the
plunger is at its lowest position, the interior of the hopper in line with the mould,
and the shaft D in motion. An attendant secures the proper supply of concrete to
the mould. The revolution of shaft D and cams d operating through lever ba
moves the hopper rearward, placing the head block 6 over the mould, thus closing
it, and shearing off the mass of concrete.
The concrete in the hopper then rests upon the cap plate a². As soon as the
mould is closed, as in Figure 7, and the hopper and head block are at rest, the valve
cam d² lifts the valve rod and admits steam through port f into the cylinder
beneath the piston, which is thereby moved upward against the confined air and
exhaust steam in the upper end of the cylinder; but after this first movement of
the piston the upper port g is slightly uncovered by the valve which allows the
compressed air to escape, and permits the piston to move freely upward under full
steam pressure, and to compress the contents of the mould to a degree equal to the
aggregate steam pressure on the piston, minus the weight lifted and the friction of
the parts; the continued rotation of the cam d² next moves the valve downward,
uncovering both cylinder ports fand g, which permit the exhaust steam to escape,
from below the piston, and air and exhaust steam to enter above the piston, where-
upon the piston and plunger fall without shock because they are cushioned by the
air beneath the plate o³, when the same has entered into the chamber, above the

page_text: cylinder. As soon as steam pressure is removed from the piston the cams d move
the hopper rearward and uncover the mould, after which the block is ejected by the
cam the hopper then moves forward, sliding the block from the plunger to the
surface of the cap plate, from which it may be delivered to an endless belt, as indi-
cated in dotted lines in Figure 1.
It will be seen that in case the mould should be entirely empty the movement of
the piston will be properly controlled, so that it will ascend gradually to its full
height without shock, and also that in case the mould has much or little concrete
therein, the blocks will be of practically the same density because subjected to the
same degree of compression. During the exhausting of the steam from the lower
end of the cylinder it will be seen that the upper port g being open the exhaust
steam may freely enter the upper end of the cylinder to serve as a cushion during
the succeeding movement of the piston.
Steam may be supplied to the said press from a boiler exclusively provided
therefor, or from the boiler which affords the motive power for driving the shaft.
The action of the steam being prompt and efficient for inducing the desired pressure
it is practicable to operate the shaft at a speed which will deliver, say, ten to twenty
blocks a minute, if the concrete be of a character which will enable the moulds to
be rapidly filled, this latter operation being the one that practically controls the
speed at which the press may be successfully operated.
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 do not limit myself to the precise construction shown, for I am aware that
other well-known mechanical devices may be employed for moving the hopper,
actuating the valve, and discharging the block without departing from the spirit of
my Invention or materially affecting its practical value; nor do I limit myself to a
valve or valves of the precise construction shewn, for while I now employ practi-
cally two valves on one rod I am well aware that each port of the cylinder may be
guarded by a separate valve of a different construction and separately actuated, and
I am also aware that the lower end of the said cylinder may be provided with two
ports, one for steam and the other for exhaust, and that these may be guarded by
separately actuated valves. I have however produced the desired results by simple
and effective means, and have avoided as far as possible unnecessary complication,
and I claim,
First. The combination with a die or mould of a plunger fitted to the mould, a
piston rod, piston, steam cylinder, and valve for successively admitting "live" steam
at the rear of the piston and exhausting it therefrom, whereby the plunger is forced
into the dio or mould by the pressure of steam on the piston, as above set forth.
Second. The combination with a mould plunger, piston rod, and piston of a
cylinder for the piston, provided with a steam and exhaust port at its rear end, a
passage or port at its front end, and the valve or valves which control the said ports
or passages, whereby when steam is first admitted to the rear end of the cylinder
the front port will be closed, and thereafter opened, as above set forth.
Third. The combination with a mould, a movable head block which opens the
mould, a plunger, a piston and its rod, and a steam cylinder and its valve of a
mechanical lifting device for forcing the plunger through the mould whereby the
compressed contents of the mould are ejected therefrom, as above set forth.
Fourth. The combination with a mould of a hopper which is smaller at the top
than at the bottom, whereby concrete may freely pass downward to the mould, as
above set forth.
Fifth. The combination with a mould, having a hardened cutting edge at its top,
of a sliding head block provided with a hardened cutting edge, whereby particles of
rock and concrete will not obstruct the movement of the block in closing the mould,
as above set forth.
Sixth. The combination with the mould and a plunger provided with ducts of a
reservoir connected with the plunger, whereby lubricating matter is distributed upon
the surface of the mould, as above set forth.

page_text: Seventh. The combination with an open mould and a movable head block of a
plunger which is adjustable with reference to the mould, whereby the cubic capacity
of the mould may be varied, as above set forth.
Eighth. The combination with the plunger, piston rod, and piston, of a head on
the rod below the plunger, and a recess or chamber to which the head is accurately
fitted, whereby the fall of the plunger rod and piston is relieved from shock by the
cushioning of air in the chamber, as above set forth.
Ninth. A mould for compressing asphaltic concrete, provided with a detachable
steel lining, as above described,
Tenth. A machine or press which embodies in its construction the above specified
novel features, or any of them, and which operates as herein described, and for the
purposes set forth.
In witness whereof, I, the said Willian Robert Lake, have hereunto set
my hand and seal, this Second day of June, in the year of our Lord One
thousand eight hundred and seventy-eight.
TUM DAT
T5
W. ROD LAKE
KE. (L.)