Improvements in and relating to Apparatus for Excavating Coal, Sand, Grain, and other like Substances or Materials.
Year: 1889

page_text: Date of Application, 8th Oct., 1889-Accepted, 9th Nov., 1889
COMPLETE SPECIFICATION.
Improvements in and relating to Apparatus for Excavating Coal,
Sand, Grain, and other like Substances or Materials.
We, THOMAS MCBRIDE, of Number 2312, Lombard Street, in the City and
County of Philadelphia, State of Pennsylvania, one of the United States of America,
Coal Dealer, and EBENEZER FISHER, of Kincarden, Province of Ontario, Dominion
of Canada, 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 stateinent :-
Our invention relates to improvements in devices for excavating coal, sand,
grain etc., and the object of our invention is to dispense with the heavy weight of
iron or other material now used in this class of devices for forcing the exca-
vating buckets or scoops into the material to be raised, and also to insure a quick
and positive closing of the scoops so as to prevent any of the material from falling
out between the scoops, and to this end our invention consists in connecting the arms
of the scoops to the winding or operating drum by means of links or bars, whereby
the power exerted to close the scoops and hold the same in a closed position, is exerted
on the outer ends of the arms of the scoops.
Our invention consists further in confining the axis of the winding drum which
operates the chains for opening and closing the scoops, in segmental or eccentric slots
formed in guide bars, whereby said winding drum is steadied and guided in its
operation.
Referring to the accompanying Drawings:
Figure 1, is an end view of our excavating bucket in a closed position.
Figure 2, is a view in perspective, showing the scoop open.
Figure 3, is a side view of one of the guide bars detached from the device.
Figure 4, is an end view of a modified form in which the winding drum is placed
at right angles to the length of the buckets or scoops, and in which the buckets are
shown in full lines in an open position, and in a closed position in dotted lines.
A, indicates the scoops forming the buckets, said scoops being of the usual clam-
shell shape, and of any suitable material which will withstand the hard usage to which
such devices are subjected, the end of said scoops being connected by the bars, B,
which give strength and rigidity to the structure.
C, are levers or arms secured to the upper inner corners of the scoops and are
bent inward at their central portions, as shown at, a, 'so that their upper ends will
set in a short distance from the ends of the scoops.
The levers or arms, C, are crossed and pivoted together after the fashion of a pair
of shears, by the bolts, b, the outer or free ends of said levers, C, being connected to
the ends of the bars, D, by means of the toggle levers, E.
The bars, D, are joined together at their ends by means of suitable stays or brace
rods, F, so as to form a frame in which the winding drum, G, is mounted.
H, are brace or stay rods, the lower ends of which are hinged to the rear upper
corners of the scoops, while the upper ends of said bars or rods are secured to the
cross bar, I, the office or function of which is to force down the scoops, while the
links or toggles are closing on the material.
The cross bar, I, to which the brace rods, H, are secured, is connected to the derrick
or other hoisting device, by means of the chain, R.
As before intimated, G, is a winding drum the ends of which are mounted in
suitable bearings in the bars, D, and around said drum the hoisting chain, L, is.
wound, the other end of said chain being passed over pulley blocks on the derrick and
to a suitable winding drum.

page_text: On each side, the drum, G, is provided with spool-shaped hubs, M, to receive
the chains, N, one end of said chains being secured to the hubs, M, the other ends
being secured to the cross-bar, I.
O are guide bars secured to the inside of the upper ends of the inner levers, C,
as shown in Figure 1, said guide bars being provided with a segmental or eccentrically
formed slot, P, through which are passed the ends or axis of the drum, G.
The object of these guide bars is to hold the drum at all times in a central position
and cause the scoops to move uniformly down into the material to be excavated and
to close on the central line.
The operation of our device is as follows:
The scoops being opened as indicated in Figure 2, they are let down onto the
material to be excavated.
The opening of the scoops and the consequent lowering of the drum, G, down
between the levers, C, causes the chain, L, to unwind from the drum and by this
motion the chain, N, is wound upon the grooved or spool hubs, M.
Power is now applied to chain, L, which turns the drum winding the chains, N,
onto the spool hubs, M, and while the chain, L, is being unwound from the drum, the
lifting power is still continued on the chain, L, and the weight of the device comes
onto the drum; the link motion causes the drum to rise above the pivot point, as
shown in Figure 1, and through the action of the toggle levers, E, and levers, C, the
scoops are closed.
After the scoops are closed the device is carried with its load to the place where it
is to be deposited, when the weight of the device with its load is transferred to the
chain, R, this pulls on the rod, H, to open the scoops and allows the drum, G, to
descend, unwinding from the spools the chains, N, and winding the chain, L, on the
drum, G.
In Figure 4, we have shown a modified form of excavator in which the drum for
operating the chains is placed at right angles to the length of the scoops, the same
principle however, applies in this case, viz. connecting the outer ends of the arms of
the scoops to the frame supporting the drum carrying the operating chains, by a
toggle lever connection, whereby the power exerted is applied directly to the outer
ends of the arms of the scoops.
In this instance the brace or stay rods, E¹, are used, one end of which is secured to
the rear upper edge of the scoops, while the other ends of said rods are secured to the
ends of the toggle levers, E, and to the outer ends of the arms or levers, C.
Having now particularly described and ascertained the nature of our inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
First In an excavating device of the character described the chain operating drum
mounted in suitable bearings in a frame, the said frame being connected to the arms
or levers of the scoops by toggle levers, and segmentally slotted guide-bars adapted to
receive the axis of the winding drum, whereby the drum is centrally guided in its
raising and falling motion to open and close the scoops, as set forth.
Second: In an excavating device of the character described, the scoops provided
with the lever arms crossed and pivoted together as described, the upper ends of said
levers being pivoted to one end of the toggle levers, the other end of said toggle levers
being pivoted to the frame which supports the chain operating drum, as set forth.
Third In an excavating device of the character described, the chain operating
drum mounted in suitable bearings in end bars, said bars being connected to the arms
For levers of the scoops by toggle levers, whereby the raising and lowering of the drum
operates to open and close the scoops, as set forth.
Fourth In an excavating device of the character described, the combination with
the winding drum, the winding wheel located thereon, and the operating chains of
the scoops, the crossed levers carrying the same, the toggle levers connecting with the
cross levers, and the edges of the scoops, the curved arms pivotally connected to the

page_text: said edges of the scoops and the connecting bar to which the upper end of said arms
are pivotally connected whereby the scoops may be lowered or elevated, and opened
or closed automatically, substantially as specified.
Fifth In an excavating device of the character described, the combination with
the cross levers fulcrumed at their intersections and carrying the scoops with the
toggle levers, connecting the said cross levers with the shaft of the winding drum,
the lower members of said toggle levers being curved to permit the drum to settle
well down between the scoops, substantially as specified.
Dated this 8th day of October 1889.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.