AN IMPROVED CONSTRUCTION OF GRABS SKIPS BUCKETS AND SIMILAR INSTRUMENTS
Year: 1884

page_text: We WALTER PITT of the Newark Foundry Bath in the County of Somerset.
Engineer and JOSEPH HENRY WILD of 12 Richmond Walk Devonport in the
County of Devon, Engineer do hereby declare the nature of our Invention for
AN IMPROVED CONSTRUCTION OF GRABS SKIPS BUCKETS AND SIMILAR INSTRUMENTS
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
Our Invention relates to a novel method of constructing skips, grabs, buckets,
diggers or other receptacles used for lifting and discharging materials and more
particularly to those skips or grabs commonly called "single chain" grabs or skips,
which are operated by one chain and in which the discharging is performed by
temporarily supporting the frame of the skip or grab whilst the bottom part is
being lowered out and opened.
The object of our Invention is so to construct such single chain grabs or skips or
similar instruments as to occupy less height than when made as heretofore and at
the same time to make a stronger and more compact machine: the saving in height
and consequent economy of headroom being an object of the utmost importance in
many situations.
"
In previous machines the top frame of the grab or skip has been made to form
a straight connection from side to side as is usual in the so called "double chain
grab; the suspended support and apparatus for attaching the grab to the same
have been kept above and clear of the above mentioned top frame and this has
necessitated the use of long connecting parts or rods between the supporting
mechanism and the opening bar of the skip or grab and at the same time required
a clear space above the top frame at least sufficient to allow the gripping gear to
make an equal travel to that of the opening bar. Now in our Invention we
construct the top frame of the grab with an opening in plan through which the
suspended support may pass, this enables us to connect the gripping mechanism
directly with the opening bar and either to reduce the length of the above-
mentioned connecting rods till they become mere bolts or to dispense with them
altogether by absorbing the gripping gear and the opening bar into one and the
saine member. The dispensing with the long rods adds greatly to the strength and
shortens the total length of the machine by several feet. The apparatus that we
prefer to use in connection with our invention is "Wilds Patent Apparatus for
Working Grabs" more particularly described in Letters Patent Number 842. One

page_text: thousand eight hundred and eighty three, but our Invention can also be applied
to other forms of working gear which require the use of a temporary support
whilst discharging. The construction and operation of the Invention will be
understood on reference to the accompanying Drawings in which Fig. 1 and Fig.
represent our improved grab fitted with a Wilds Patent Apparatus Fig. 3. Fig. 4.
Fig. 5 represent a grab somewhat similar to Figs. 1 and 2 but with a different
form of opening bar, the opening bar and the Wilds apparatus being made in one.
In Fig. 1 the grab is shown at the top of the lift just previous to being lowered
on to the ring support G for discharge-If the grab is now lowered the hooks F
engage with the ring G and by the rodsk (which are here made very short) support
the opening bar K. and on the lowering being continued the grab opens and is
discharged. In order to keep the rods k short and attach the apparatus directly to
the opening bar K it will be seen that the ring G has to pass entirely within the
frame of the grab and to permit of this the top frame is constructed in the form of
a ring L so as to allow it to pass up freely round G.
In Figs. 3 and 4 the rods k are suppressed altogether and the opening bar K
Fig. 1 is made in one piece with the crosshead A (Fig. 1) of the discharging
apparatus It will be readily seen that when L-Fig. 1 is made straight across as
heretofore the rods k must pass through holes in it and the crosshead A must work
entirely above it and consequently the frame L cannot approach the suspended
support G.
In the Drawings the other details of the discharging gear remaining unaltered
from those described in Wilds Patent Number 842. One thousand eight hundred
and eighty three, and the parts are here marked with the same letters as in Wilds
Drawings.
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
1 Making the top frame which connects the upright sides of a skip or grab
with an opening large enough to permit of the passage through it of the suspended
support G or its equivalent.
2nd Attaching the parts which connects the grab and support directly to the
opening bar so as to dispense with the long rods k or their equivalent and thereby
shortening the whole apparatus.