IMPROVEMENTS IN SELF- ACTING BUCKETS, GRABS OR SKEPS FOR RAISING AND DISCHARGING GRAIN VD ARF
Year: 1882

page_text: LETTERS PATENT to George Martin Key and James Lowrie, both of Limehouse
in the County of Middlesex for an Invention of IMPROVEMENTS IN SELF-
ACTING BUCKETS, GRABS OR SKEPS FOR RAISING AND DISCHARGING GRAIN
VD
ARFRA
PROVISIONAL SPECIFICATION left by the said George Martin Key & James
Lowrie at the Office of the Commissioners of Patents on the 18th November
1882.
GEORGE MARTIN KEY and JAMES LOWRIE, both of Limehouse in the County of
Middlesex "IMPROVEMENTS IN SELF-ACTING BUCKETS, GRABS OR SKEPS FOR
RAISING AND DISCHARGING GRAIN AND OTHER CARGOES AND FOR EXCAVATING
AND THE LIKE
"
Our Invention relates to an improved grab bucket or skep for raising or
discharging grain or other cargoes in bulk, for excavating or dredging and for other
purposes.
The grab bucket or skep of our Invention is so constructed as to open and close
automatically so as to be self filling and self discharging by the mere act of raising
and lowering it without the aid of the cumbrous gear usually required to operate it.
The grab bucket or skep proper is of the usual hemispherical or semi-cylindrical
form and is made in two parts connected together by and pivoted to a suitable
frame so as to open and close in the usual manner and may be constructed of
solid plates or of tines or prongs or otherwise according to the nature of the
material to be raised.
It is suspended and worked by a single chain the opening and closing being
effected through the medium of two sets of connections so attached to the two
halves of the bucket or skep that an upward strain on the one set opens and on
the other set closes the bucket. These two sets of connections are respectively
attached to two cross heads or slides capable of independent vertical movement
and situated the one above the other. The lower cross head is attached to the
lower ends of a pair of guide rods upon which the upper cross head is free to slide
Din 27

page_text: and the one or the other of these two sets of connections and crosshends is made
to support the weight of the bucket or skep at required moments through the
agency of a self acting tumbler or a quadrant shaped link by which the bucket or
skep is connected to the suspension chain and which is made to connect with the
one or other crosshead in the following manner. This tumbler or quadrant link
oscillates in a vertical plane being pivoted to a cross bar sliding on the guide rods
above mentioned and it is connected to the suspension chain in such a manner
that when the latter becomes slack by the weight of the bucket or skep being
taken off by coming to rest upon any support the chain upon being again tautened
seizes the tumbler or link in such a way as to oscillate it and cause it to occupy
a new position and become engaged with or disengaged from one of the crossheads
as hereafter explained. For this purpose the chain is connected to the tumbler or
link by a block which embraces the curved part or are and has pins so disposed
as to be caused to bite the said curved part or arc when a lifting strain comes on
the block after the latter has assumed a horizontal position in consequence of a
previous slackening of the chain. This tumbler or link has a hooked projection
adapted for engagement at the proper moment with the upper crosshead.
The operation is as follows. Supposing the hook of the quadrant link to be
engaged with the upper crosshead, the strain will then be borne by the latter and
its connections and the bucket or skep will be opened and when it plunges into
the grain or other matters to be raised, the chain being relieved of the weight
becomes slack and allows the block by which it is connected to the tumbler or link,
to slip down the curved part or arc of the latter and assume such a position that
when slack of the chain is taken up previous to drawing up the bucket or skep,
the block is caused to bite the tumbler, oscillate or throw it over to the other side,
and thus disengage its hook from the upper crosshead. The chain thereupon at
first draws up the tumbler alone until the strain comes upon the guide rods and
the lower crosshead whereupon the bucket is first closed and then raised with its
load, the strain coming entirely upon the lower crosshead and its connections.
The loaded bucket or skep is discharged by being lowered onto a bed-or-support
whereupon the chain becomes slack, its block slips down the quadrant link or
tumbler, and when the chain is drawn up again the block grips the link or
tumbler and throws it over to its former position, thus causing its hook projection
to re-engage with the upper crosshead so that the strain will then come on the
latter and will therefore cause the bucket to open and discharge its contents in
the act of rising, the bucket remaining open until again lowered and filled as
before.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Martin Key & James Lowrie in the Great Seal Patent
Office on the 18th May 1883.
GEORGE MARTIN KEY and JAMES LOWRIE both of Limehouse in the County of
Middlesex "IMPROVEMENTS IN SELF ACTING BUCKETS, GRABS, OR SKEPS FOR
RAISING AND DISCHARGING GRAIN AND OTHER CARGOES, AND FOR EXCAVATING
AND THE LIKE
"
Our Invention relates to an improved grab bucket or skep for raising and
discharging grain or other cargoes in bulk, for excavating or dredging, and for other
purposes.
This grab bucket or skep is so constructed as to open and close automatically
and be self filling and self discharging without the aid of the cumbrous gear usually
required. The grab bucket or skip proper is of the usual hemispherical or semi-
cylindrical form made in two parts connected together by, and pivoted to a suitable
frame so as to open and close in the usual manner. It may be constructed of solid
plates or of tines or prongs or otherwise, according to the nature of the material to
be raised. It is suspended and worked by a single chain, the opening and closing
being effected through the medium of two sets of connections so attached to the two
halves of the bucket or skep that the,strain due to its own weight coming on the
one set opens, and on the other set closes, the bucket. These two sets of con-
nections are respectively attached to two cross heads or slides capable of independent
vertical movement and situated the one above the other. The lower crosshead is
attached to the lower ends of a pair of guide rods upon which the upper crosshead
is free to slide, and the one or the other of these two sets of connections and cross-
heads is made to support the weight of the bucket or skep at required moments
through the agency of a self acting tumbler or a quadrant shaped link in connection
with and operated by the suspension chain. This tumbler or quadrant link
oscillates in a vertical plane, being pivoted to a cross bar which slides on the guide
rods above mentioned, and it has a hooked lug adapted for engagement at the
proper moment with the upper cross-head,
DESCRIPTION OF DRAWINGS.
Figures 1 and 2 are side and end elevations of the grab bucket or skep open,
and Figure 3 is an end elevation of the same closed. Figures 2* and 2 are details
of the self acting tumbler and its connections with the suspension chain by which
the weight is thrown upon the one or other set of connections, according as the
bucket is to be opened or closed.
A A are the two halves of the bucket pivoted between the ends B' of a frame B
and working on bolts C extending across from one end B¹ to the other. D is the
lower cross-head, and E are two pairs of levers pivoted upon the bolts C and bolted
at their outer ends to the top outer edges of the halves A A, and connected at their
inner ends by links e to the opposite ends of arms d bolted to the ends of the
crossbead D. F are the pair of guide rods extending upwards and passing freely
through B and joined at top by a yoke or slotted link f for the suspension chain
to pass through, said yoke being provided with a central sheave f¹ for the chain to
work against G is the upper crosshead mounted to slide upon the guide rods F.
H are links jointed respectively to the crosshead G and to the top outer edges of
the halves A A as shown. g is a staple or eye fixed on the crosshead G for the
hook of the tumbler to engage with. I is the tumbler crosshead also fitted to

page_text: slide on the guide rods F. It is separated from the crosshead G by tubular sliding
distance pieces i. K is the tumbler pivoted loosely upon the centre of the sliding
crosshead I and provided with a hooked lug L adapted to engage with the eye g
of crosshead G. It is also formed with a quadrant shaped part having an undercut
notch & in it, this quadrant shaped part preponderating on weight so as to cause
the tumbler to assume the position shown in Figure 2b when free from strain.
is a stop to limit its motion in this direction. M is a forked radius link or
stirrup piece pivoted on the crosshead I at either side of the tumbler which it
embraces between its limbs. Its pivoted ends have elongated slots so as to permit
of a longitudinal motion of the link of sufficient extent to enable a cross pin m
fixed in its limbs to engage with and become disengaged from the undercut notch k
of the tumbler. m is a weight fixed on this link to ensure it falling in the
direction of the notch when the chain is slackened. N is the suspension chain
by which alone the bucket is raised, lowered, opened and closed through the agency
of the connections above described. It is attached to link M and passes through
yoke f.
In Figures 1 and 2 the weight is supported by the chain N, link M, crosshead I,
tumbler K, hook L, crosshead G, and connections H. The weight of the frame B
and of the parts A thereby causes the latter to assume the open position shown.
Immediately the bucket plunges into the grain, the chain slackens and the tumbler
being already free of the pin m, falls into the position shown in Figure 2, thereby
disengaging its hook L from crosshead G. Upon then drawing up the chain,
the crosshead I slides up the rods F until it strikes against the shoulders f² as in
Figure 2b, whereupon the weight comes on the guide rods F and the lower cross-
head D whereby the halves A of the bucket are first closed together through the
agency of links e and levers E as shown in Figure 3 and the bucket is then raised
with its load. The loaded bucket or skep is discharged by lowering it on to a bed
or other support and slackening the chain sufficiently to let the tumbler slide
down to the cross head G and the link M to fall over with the cross pin m resting
in rotch as shown in Figure 3ª. Upon again tightening the chain the cross pin m
_ engages the undercut part of the notch-b-and-raises the tumbler-until-the-book-L
re-engages with crossliead G, whereupon by continuing to draw up the chain, the
strain comes on said crosshead and thereby causes the bucket to open and discharge
its contents in the act of rising, the bucket remaining open as in Figures 1 and 2
until again lowered and filled as before.
Figure 4 represents a modification in which the lower crosshead and the lever
connections are dispensed with and the opening and closing of the bucket is
effected wholly through the crosshead G and links H. To effect this the cross-
bead I is connected to the crossbead ( by chains P which pass under sheaves p on
frame B, and over sheaves on crosshead I. p₁ are weights forming stops and
serving to take up the slack of the chains P when the crosshead I is lowered, as
will be readily understood. The links H are in this case double and splayed
outwards towards the corners of the bucket, and the guide rods F are rigidly bolted
to the frame B. The tumbler K and link M are the same as before and the action
will be readily understood. In the position shown the weight is on the chains P
whereby the crosshead G is drawn downwards and links H are forced outwards,
thereby closing the bucket, but when the tumbler has been caused to engage with
the crosshead Gas before explained, the strain comes on said crosshead and links H
in the opposite direction and the weight of the frame B and parts connected
therewith throws the parts A-open.--
Having described the nature of the said Invention and the manner of performing
the same, we would observe that we are aware that it has before been proposed to
suspend and operate such grab buckets or skeps by one and the same chain but
that what we claim as the Invention to be protected by the herein before in part
recited Letters Patent is.
1 In a grab bucket or skep, the combination with a single suspension chain
and with the connections whereby the two halves of the bucket are caused to open

page_text: and close by their own weight as herein described, of means interposed between
the suspension chain and the said connections, whereby the weight of the bucket
may be transferred to the one or other set of connections at. required times for
opening and closing the bucket substantially in the manner herein specified.
2nd In a grab bucket or skep, the combination with a single suspension chain
and with connections whereby the two halves of the bucket are caused to open
and close by their own weight, as herein described, of the oscillating tumbler hook
and its sliding support arranged to operate substantially in the manner herein
described and shown in the drawings for the purpose specified.
3rd In a grab bucket or skep the combination of the two sets of connections and
their respective crossheads, the guide rods attached to one crosshead, the oscillating.
tumbler hook and its sliding support respectively adapted to engage with the
sliding crosshead and the guide rods, the mechanism for throwing the said hook
into engagement and the suspension chain, the whole combined and arranged to
operate, substantially in the manner and for the purpose herein specified and shown
in Figures 1 to 3 of the drawings.
In Witness I the said James Lowrie for myself and on behalf of the said
George Martin Key have hereunto set my hand and seal this seventeenth
day of May, A.D. 1883.
J LOWRIE (L.S.)