Year: 1886

page_text: We JAMES SHANKS Engineer Arbroath and JAMES GORDON LYON Engineer
Arbroath do hereby declare the nature of this Invention to be as follows:-
The Invention relates to the Grab or Excavator proper and to the arrangement
at the Gib head for operating the said Grab or Excavator proper. The buckets of
the Grab or Excavator may be of any suitable shape or kind and they are attached
to the crosshead by a hinge joint-To each of the buckets are jointed the ends of
knuckle levers jointed at their other ends to the crosshead. To the knuckle pins
of these levers are attached by means of links the heaving chains, The opening
chains are also attached by similar links to the said knuckle pins-Bolts rollers or
pulleys are provided in the crosshead for guiding the heaving chain. When the
Grab is filled and has been lifted to the height at which its contents are to be
discharged the heaving chains are lowered and the opening chains are prevented
from lowering so that the latter haul up the buckets by the pins forming the
knuckle joints before mentioned and so open the said buckets. If then the Grab
be allowed to fall to the earth or matter upon which they are operating and tho
heaving chains be wound up the buckets will then close and fill themselves. The
Grab is then raised to the required height and the contents discharged as herein- .
before explained.
The following is an arrangement of Grab by which these operations can be
performed. On the gib head are two pulleys with projections on their peripheries.
between which the links of the heaving and opening chains are respectively held..
Attached to the pulley of the lowering chain is a brake wheel encircled by a brake
strap. This brake strap is operated by a bell crank and lever in the usual manner-
A stop is cast on the face of the said pulley and a corresponding stop cast on the
face of pulley of the heaving chain-Suppose the Grab to be resting on the earth
and the crane to be put in operation to lift it, as the links of that chain fit the
recesses in the periphery of the pulley over which it passes it follows that the said
pulley is carried round by the chain and that when the stop or projection thereon
comes into contact with the stop on the pulley of the lowering chain that pulley
ונס....D

page_text: also revolves and carries up the slack of the running chain-When the Grab has
been lifted to the necessary height the brake is tightened thus preventing the
pulley of the lowering chain from revolving and as the heavy chain is lowered
away the pulley thereof revolves until the stop thereon comes into contact on the
opposite side of the stop on the pulley of. the lowering chain the distance which the
pulley is allowed to travel being the amount required for opening the Grab. The
brake is then slightly eased and the Grab lowered until it strikes the earth these
operations being repeated whilst the apparatus is at work.
J. HENRY JOHNSON,
47, Lincoln's Inn Fields, London,
Agent for the said James Shanks and
James Gordon Lyon.

page_text: We, JAMES SHANKS and JAMES GORDON LYON both of Arbroath, North Britain,
Engineers, 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 statement:-
This Invention relates to the grab or excavator proper and to the arrangement at
the Jib head or elsewhere for operating the said grab or excavator proper. We will
describe our Invention with reference to the accompanying drawings whereon
Figure 1 is an end sectional view and Figure 2 is a partial side elevation and
longitudinal section shewing the grab in the closed position and Figure 3 is an end
view shewing the grab in the open position Figures 4 and 5 are respectively a
section and a side view of the arrangement for operating the grab.
Referring first to Figures 1, 2 and 3, A represents the buckets of the grab or
excavator proper, which may be of any suitable form or kind, and are attached to
the cross-head B, by hinge joints C. To each of the buckets at D, are jointed the
ends of knuckle levers E, the said knuckle levers being jointed together at G and
at their other ends they are jointed to the cross-head B, by the pins H. To the
knuckle pins G are attached by means of the links K the heaving chains J. The
opening chains L are also attached by similar links K' to the knuckle pins G—
M are bolts rollers or pulleys in the cross head for guiding the heaving chains.
Referring to Figure 1 let it be supposed that the grab is filled and has been lifted
to the height at which its contents are to be discharged-The heaving chains J are
lowered and the opening chains L are prevented from lowering so that the latter
will haul up the buckets A by the pins G and so open the said buckets as shewn in
Figure 3. If then the grab be allowed to fall to the earth or matter which is being
operated upon and the heaving chains J be wound up, the buckets A will then
close and fill themselves with the earth or other matter. The grab is then raised
to the required height and the contents are discharged as hereinbefore described.
The following is an arrangement of gear, by which these operations can be
performed. Referring to Figures 4 and 5, on the jib head or in other suitable
position are two pulleys with projections, or other peripheries, between which the
links of the heaving and opening chains are respectively held. M¹ is the pulley
round which the heaving chain runs, and N is a pulley for the chain L. Attached
to the pulley N is a brake wheel O, encircled by a brake strap P which is operated
by a bell crank Q and a lever R in the usual manner of operating such brakes.-
S is a stop, cast or fixed on the face of the pulley M³, and T is a corresponding stop,
cast or fixed on the face of the pulley N-Suppose the grab to be resting on the
earth and the crane to be put in operation to lift it, as the links of the heaving
chain fit the recesses in the periphery of the pulley M¹ it follows that the said
pulley is carried round by the chain and that when the stop or projection S comes
into contact with the stop T on the pulley N that pulley also revolves and carries
up the slack of the chain L. When the grab has been lifted to the necessary height
the brake P is tightened thus preventing the pulley N from revolving and as the
heaving chain is lowered away the pulley M₁ revolves until the stop S thereon
comes into contact with the opposite side of the stop T the distance which the
pulley is allowed thus to travel being the exact amount required for opening the

page_text: grab. The brake is then slightly eased and the grab lowered until it strikes the
earth or material to be operated upon these operations being repeated whilst the
apparatus is at work. It will be understood that although we have shewn the
operating pulleys as being applied to the jib head yet that they may be applied to
the barrel of the crane or to any other suitable part of the apparatus and it will be
further understood that the improvements in the grab or excavator proper and the
improvements in the gear for operating it may be used in conjunction with any
other suitable operating mechanism or grab respectively which may be suitable to
operate the said grab or to be operated upon by the said operating mechanism
respectively.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we declare that what
we claim is :-
First: In excavating apparatus the arrangement and combination of parts con-
stituting the grab or excavator proper substantially as herein before described and
illustrated in Figures 1, 2 and 3 of the accompanying drawings.
Second-In grabs or excavators the knuckle levers E connected with the cross-
head and buckets and operated by the chains J and L substantially as hereinbefore
described and illustrated by Figures 1, 2 and 3 of the accompanying drawings.
Third-In excavating apparatus the arrangement of pulleys stops and brake
substantially as hereinbefore described and illustrated by Figures 4 and 5 of the
accompanying drawings.
Fourth-In excavating apparatus the pulleys M and N provided with stops S
and T and operating substantially as hereinbefore described and illustrated by the
accompanying drawings.
Fifth In excavating apparatus the arrangement of grab or excavator proper
and means for operating it substantially as herein before described and illustrated
in Figures 1 to 5 of the accompanying drawings.