Year: 1889

page_text: and closing the same; and it consists in an improved form and construction of the
bucket sections, means for journaling, bracing, and operating the same, and in certain
details of construction, all of which will be more fully explained by reference to the
accompanying drawings, in which
Figure 1 is an elevation of my excavator, showing one bucket-section in cross-
section.
Figure 2 is a top view of the excavator.
Figure 3 is a perspective view of one of the bucket-sections.
Figure 4 is an end view of the valve.
Figures 5, 6, 7, and 8 are horizontal sections of the valve and chamber, showing
their different relative positions.
A is a cylinder of any suitable dimensions, suspended so as to hang vertically from
tackle which is connected with a hoisting derrick, so that the cylinder and its attach-
ments can be raised and lowered by the derrick, and swung to any other point where
the load is to be deposited, when operating.
The opening and closing of the bucket is effected by the pressure of steam, air, or
other medium acting upon a piston which moves vertically within the cylinder.
The piston-rod B extends downwardly through a stuffing-box in the lower
head of the cylinder, and its upper end passes through the upper cylinder-head,
as shown.
Upon the upper end of the cylinder is a bracket or standard D, with an attach-
ment at its upper end, to which the cable is fastened, whereby the apparatus is
raised and lowered.
This bracket is high enough above the cylinder-head to allow the upper end of the
piston-rod to rise as high as may be necessary without striking the bracket.
The excavating bucket is formed of sections G, which, when closed together, form
a cup or continuous vessel, shaped something like a flattened hemisphere. The
object of these variations from the hemispherical form will be more fully described
hereafter.
Each of these sections, which together form a complete bucket, has a strong, heavy,
central rib H, extending from the point or shoe along the inside and up to the upper
end of the section, from which an arm or continuation extends upwardly to a point
above the cross-head C. A shoe or point I, made of heavy steel, is fitted to the point
of each of the segments, abutting against the end of the strengthening ribs H, and
serving to dig or excavate the material to be operated on. These shoes may be
removed to sharpen, and replaced when worn out, with little trouble.
Shafts K extend horizontally across the top of each segment, and a solid filling of
iron is fitted between these shafts and the upper edges of the sections through which
they are strongly bolted.
These shafts are, preferably, curved inwardly, as shown in the plan view, Figure 2,
so as to act as trusses to brace and strengthen the segments. To the lower end or
head of the cylinder A, are cast or secured the arms L, which extend outwardly and
downwardly at an angle from the cylinder, as shown, and on their outer ends are
formed journals, into which the ends of the shafts K enter, these ends being turned
so as to fit the journal-boxes and rotate in them when the bucket-sections are opened
or closed.

page_text: These journal-boxes may be adjusted upon the arms L, to stand nearer to or farther
from the center, and the amount of opening of the bucket-sections is thus controlled.
The central strengthening ribs H, are extended above the upper edges of the
sections, as previously described, being bent inwardly as shown in Figures 1, and 3;
and by means of the connecting rods M, their upper ends are united with the cross-
head C, which is strongly secured to the lower end of the piston-rod, so that as the
latter is depressed by the downward movement of the piston, these extensions or
arms H are drawn downwardly and inwardly, throwing the bucket-sections outward,
and opening them about the journals upon which they turn.
When pressure is applied beneath the piston in the cylinder to force the piston up,
it carries with it the cross-head C, and acting through the connecting rods M, it
forces the arms H, first upwardly and finally outwardly, thus closing the bucket-
sections and forcing the points together.
The action of the inwardly-bent arms H, and the connecting rods M, is similar to
that of a toggle-joint because as the cross-head rises, the connecting rods M, come
more nearly into a position perpendicular to the arms H, which incline inwardly from
the top of the bucket-sections, and thus exercise a powerful direct pressure which is
exerted upon the bucket-sections to force the points together.
Owing to the changing position of the connecting rods M, the power to force the
sharp-pointed sections through hard material increases as the sections penetrate
deeper, and at the time when the greatest power is required. In order to overcome
the tendency of the bucket-sections to twist out of shape when power is applied to
them, and when working in hard or rocky ground, I employ brace-rods N, the lower
ends of which pass through the bucket-sections near the outer edges at the abrupt
bend in the segments, and the upper ends are bolted to the arms H, as shown.
Experience has shown that a segment of a perfect globe or hemisphere does not
do satisfactory work, because the excavated. material piles up in an irregular manner
when the sections are closed together.
For this reason the sections of my bucket are formed as shown in Figures 1, and 3,
the upper portion extending downwardly from the upper edge in a nearly vertical
direction when the sections are closed together, curving gradually towards the center,
and extending from this point toward the shoe in a more flattened curve, as is plainly
shown in the drawing, Figures 1, and 3.
This construction allows the excavated material to slide well up from the point
toward the sides, thus filling the bucket more evenly than when the hemispherical
sections are used. The connecting rods M, which unite the cross-head with the
inwardly-inclined arm H from the bucket, are V-shaped in form, the united end or
point of the V, connecting with the arm, while the open or separate ends are journaled
upon shafts upon the cross-head C, thus making strong and rigid connection between
the two. The arms L, extending out from the bottom of the cylinder, and which
carry the journal-shafts of the bucket-sections are strongly braced from the upper
flange of the cylinder by brace-rods R.
Steam or compressed air is brought to the operating cylinder through a flexible
jointed or telescopic pipe, which will allow the apparatus to be moved freely as may
be desired, and in order to utilize the expansive force to the fullest extent within the
cylinder, I employ a four-way rotary valve P, which turns within a valve-chamber
upon the top or upper head of the cylinder.
This valve-chamber is constructed with four ports, marked 1, 2, 3, and 4 respectively.
No. 1, at the right, receiving steam or air. No. 2 connected with the bottom of the
cylinder. No. 3 with the top of the cylinder, and No. 4 with the exhaust. Steam
or compressed air is first admitted through the ports 1, and 2, by turning the
"valve so that these ports correspond with the passage 5 in the valve, and it passes
thence into the bottom of the cylinder and forces the piston to the top, the upper
end of the cylinder being connected with the exhaust; thus acting through the
piston-rod to close the bucket-sections, in which condition they remain until the
apparatus has been hoisted by means of the derrick, and turned to the place where it
is desired to discharge the load.

page_text: The valve is then turned by the lever Q, until the ports 2, and 3 are connected by
means of the passage 6 in the valve, and this allows steam or air to pass from the
bottom to the top of the cylinder, and relieving the piston from pressure from below,
the bucket-sections will then partly open by the weight of their load.
Another turn of the valve connects the port 2, from the bottom of the cylinder, and
the exhaust-port 4, by means of the passage 7, thus allowing the steam or air to
exhaust from the bottom of the cylinder, while the portion remaining above the
piston expands and forces the piston down, and throws the bucket well open.
A still further movement of the valve connects the ports 3, and 4 by the passage 8,
thus allowing steam or air to exhaust from the upper end of the cylinder.
The valve being again returned to its first position after the apparatus has been
placed ready to take another load, the bucket-sections will again be closed, as above
described.
By this construction, the air or steam which is admitted below the piston to close
the bucket-sections, is transferred to the upper end of the cylinder where it acts
expansively to force the piston down and open the sections to discharge the load, thus
doing double service and economizing the air or steam.
I have also greatly strengthened the bucket-sections; improved their form and
capacity for entering and excavating dry or hard material, and improved the
mechanism by which they are closed, making it more direct and operative.
Having now particularly described an: ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. An excavator, comprising the concave, flattened, spheroidal segments, the
horizontal shafts or trunnions, about which the upper ends of the segments turn,
the points with supplemental, removable shoes, closing downwardly about a common
center, the central strengthening ribs with continuations at their upper ends, a cross-
head fixed to the piston-rod of the suspended operating cylinder, and connecting
rods from the cross-head, by which the excavating sections are opened and closed,
as described.
2. The radially-diverging arms fixed to the lower head of the operating cylinder
with journal-boxes in which the trunnions of the excavator bucket-sections turn, as
described.
3. The trunnion-shafts extending across the tops of the excavator-sections and
having the central parts bent inwardly to form braces, as described.
4. The peculiarly-shaped and strengthened excavator-segments, journaled in radial
arms diverging from the lower cylinder-head, a cross-head fixed to the piston-rod,
and intermediate connecting mechanism, by which the segments are opened and
closed about a common centre, and means for suspending the cylinder and raising and
lowering it with the excavator, as described.
5. The valve-chamber fixed to one end of the cylinder so as to move with it, and
the rotary, segmental valve with ports, operating lever, and pipes connecting with
both ends of the steam cylinder, as shown.
Dated this Tranter first day of Mo., 1980
For the Applicant,
W. E. GEDGE,
Agent.