Year: 1887

page_text: Date of Application, 25th Oct., 1887
Complete Specification Left, 25th July, 1888
Complete Specification Accepted, 31st Aug., 1888
I CHARLES DAVY of 30 Whitworth Road Ranmoor, Sheffield in the County of
York, Engineer do hereby declare the nature of this invention to be as follows:-
In overhead travelling cranes as generally constructed the longitudinal and transverse
driving shafts are supported in tumbler bearings which are lowered to allow the
mechanism which takes the power from the shaft to pass. These tumbler bearings are
expensive to make and their employment is open to many objections. For instance,
should the rails on which the crane travels get out of parallel with the driving shaft,
the shaft and the bearings will be subjected to considerable strain and wear.
The object of my invention is to obviate these and other disadvantages, and to this
end, I dispense with the tumbler bearings and take the power from the driving shaft
(whether the main driving shaft or the similar shafts which transmit power to the
hoisting crab) by means of a toothed drum supported in bearings in the framing of
the traveller (or the hoisting crab) and adapted to gear with spur wheels keyed on the
driving shaft. The teeth of the drum, as the crane travels along, slide through those
of the spur wheels which are placed at such a distance apart that one of the spur
wheels will always be in gear with the drum. By this means, it will be seen that I
can support the shaft in ordinary fixed bearings.
The drum is preferably placed above the driving shaft so that should the rails get
out of parallel with said shaft and the drum be consequently moved somewhat to either
side, the spur wheels will still remain in gear with the drum.
Dated this 5th day of Ontahan 1007
CHAS.
DAVY.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: Improvements in Overhead Travelling Cranes.
I, CHARLES DAVY, of 30, Whitworth Road, Ranmoor, Sheffield, in the County of
York, 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 statement :- :
In overhead travelling cranes, the longitudinal and transverse driving shafts are
usually supported at intermediate points by-what are termed tumbler bearings--that is
to say bearings supported by counterweighted pivoted or sliding brackets-so that
they may be lowered to give passage to the sleeve or mechanism that slides along and
takes the power from any point of the shaft. These tumbler bearings are expensive to
construct and maintain, and their employment is open to many objections.
The object of my invention is to dispense with the tumbler bearings and to provide
means whereby sliding connection may be maintained with a shaft mounted in ordinary
fixed bearings whether it be the main driving shaft or the transverse driving shafts
which transmit power to the hoisting crab. The means whereby this is effected,
consist of a toothed drum mounted parallel to the driving shaft but in the travelling
gantry or the crab to which power is to be transmitted from said shaft, the said drum
gearing with spur wheels keyed on the driving shaft at distances apart less than the
length of the toothed drum, so that the teeth of the latter will slide across those of the
spur
wheels and will always be in gear with at least one spur wheel on the driving
shaft. The drum is preferably placed above the driving shaft so that should the rails
get out of parallel with said shaft, the drum although not quite in the same vertical
plane with the shaft will nevertheless still remain in gear with it without causing any
undue strains and wear such as result under corresponding circumstances when
tumbler bearings are used.
Reference is to be had to the accompanying drawings forming part of this
specification wherein figure 1 is a sectional end elevation of the travelling gantry
shewing the mode of communicating motion from the main driving shaft to the
gearing on the gantry. Figure 2 is an elevation showing the application of the same
means of communicating motion from the driving shaft on the travelling gantry to the
crab or carriage traversed along said gantrys. The same letters of reference serve for
like parts in both figures.
In figure 1, A is the main driving shaft supported by fixed bearings B.and receiving
constant motion in the usual way. It is an ordinary round shaft (instead of being
square as usual) and has a series of spur wheels C keyed upon it at equal distances
apart. D is a toothed drum or spur wheel of a length greater than the distance
between two adjacent wheels O in order that as the drum moves along in the direction
of its axis, its teeth will slide across those of the wheels C and will not become;
disengaged from one of said wheels before being engaged with the next wheel in
advance, in order that the drum may be always in gear with the shaft A. In the
spaces or any of them thus bridged over by the drum, the bearings B are situated.

page_text: In figure 1, this toothed drum D is mounted at the end of the travelling gantry E
with its axis parallel to, and above, the main shaft A and by its means motion is
imparted from the main driving shaft A to the reversing cone shaft or other reversing
device giving motion in any suitable manner and at required times to the longitudinal
traversing, cross-traversing, and hoisting gears. The reversing and other gears need
no description as they form no part of this invention.
In figure 2, the shaft A is one of the shafts upon the travelling gantry by which
motion is imparted to the gear on the carriage or crab for hoisting the load, a similar
arrangement of shaft and gear being used for traversing the crab on the gantry. The
shaft A is mounted in fixed bearings B along the girders E figure 1 of the gantry
and has spur wheels C keyed on it, as before, which gear with a toothed drum Ď
mounted on the carriage or crab F, motion being communicated from the drum D to
the hoisting (or traversing) mechanism of the crab by any suitable gearing which
need not be described as it forms no part of the present invention. In this case, the
shaft A whether it be used for driving the hoisting or traversing mechanism receives
intermittent motion that is to say it is started, stopped, and reversed at required times
by the reversing clutches or other reversing gear, before referred to.
In both cases, the wheels C are of course so keyed on the shaft A that the teeth of
the several wheels shall be in alignment with each other and the teeth of the long
wheel or drum D are bevelled at the ends, as at d, to ensure their sliding easily into
engagement with those of the wheels C.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed I declare that what
I claim is
In an overhead travelling crane, the combination with a driving shaft having spur
wheels keyed upon it at intervals, as described, of a toothed drum parallel to said shaft
mounted upon the travelling or traversing part (as the case may be) of the crane and
engaging always with at least one of the wheels on the driving shaft, so as to remain
constantly in gear with the latter, as and for the purpose specified.
Dated this 25th day of July 1888.
C. DAVY.
By A. M. & Wm. Clark,
53, Chancery Lane, Loudon,
Patent Agents.