Improvements in Cranes, specially applicable to Electrically Driven Cranes.
Year: 1896

page_text: Date of Application, 20th Feb., 1896-Accepted, 16th May, 1896
.
COMPLETE SPECIFICATION.
Improvements in Cranes, specially applicable to Electrically
Driven Cranes.
I HENRY BERRY of the Croydon Works, Hunslet, Leeds in the County of.
York Mechanical 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:-
My invention has for its objects and advantages a simple arrangement whereby.
the hoisting and lowering gear may be so driven, that not only is the rate of
lowering much faster than that of hoisting, but two different rates of hoisting and
two different rates of lowering are provided, in order to suit the varying loads to
be moved; and also the mechanism is much more compact, extending to a much.
less depth below the crane girders than is usual in such cases.
My invention is hereunder described with reference to shop travelling
cranes, but as will be evident is more or less applicable to other descriptions of
cranes.
My invention consists essentially in driving two transverse shafts at different
speeds from the first motion shaft, and in driving a short longitudinal worm shaft
from one or other of the transverse shafts through a differential cone gearing.
device. Such differential arrangement consists of a large wheel on the end of the
longitudinal worm shaft, having a large and a small cone friction gearing surface.
formed on the outer surface thereof; whilst the transverse shaft is provided with
two cone friction wheels, respectively on opposite sides of the intersection of the
two (i.e. longitudinal and transverse) axes, the one gearing with the larger cone-
and the other with the smaller cone surface on the above mentioned large wheel.
Both the cone wheels are fitted on or connected to a long sleeve, riding over a key
or feather on the transverse shaft, so that the cones can be slid simultaneously and
longitudinally along the shaft. The cone wheels are fixed at such a distance
apart by the sleeve, that only one of the cone wheels is in gear with its
corresponding cone surface on the large wheel at a time. The pulleys of the two
transverse shafts are most conveniently on opposite sides of the crane girder or
girders. The hoisting barrel is driven from the worm on the worm shaft by means:
of intermediate toothed gearing, conveniently comprising two intermediate shafts,
to obtain the desired or required reduction of speed.
And in order that my invention and the manner in which the same is to be
performed may be more readily and clearly understood, I have annexed hereto the
accompanying sheet of drawings, more or less diagrammatically illustrating my
invention; in which
Fig. 1 is a side elevation of one end of the traveller with the mechanism
comprising my invention, Fig. 2 is a plan, and Fig. 3 an end elevation.
Fig. 4 is a separate plan view, partly in section, of the differential cone gearing
device.
In all the figures the same reference letter is used to indicate the same or
corresponding part.
A. A. are the side girders of the traveller, B is the hoisting or lowering barrel,
Cis one of the wheele carrving the traveller and running on the rail D.

page_text: a is the first motion shaft, driven by the electric motor, and provided at the
ends with driving pulleys b and b³ respectively.
c and care the above mentioned transverse shafts, the shaft c carrying at one
end the pulley d. and the shaft c¹ carrying at one end the pulley d'. The pulleys d
and d, which are driven respectively from the pulleys and b, are corre-
spondingly placed on opposite sides of the traveller respectively. On each
transverse shaft (c, c') is fitted a sleeve (e, e',) fitted thereon, with a key or feather
arrangement to permit of the sleeve (e, e',) being moved longitudinally on the
shaft (c, c¹). The opposite ends of the sleeve (e, e',) carry respectively the cone
friction wheels (f, g, 1 g). Between the shafts (c, c) is placed the longitudinal
worm shaft h, which carries at the opposite ends the large wheels k, k respectively.
On the outer face of each wheel is formed the large and small cone friction
gearing surfaces or wheels (m, n, m', n¹).
i is the worm fixed on the worm shaft, and which by means of the gear wheels.
on the intermediate shafts ; and 1, drives the large wheel p connected to the
barrel B or the barrel axle g.
The distance of the cone wheels f, g, (f), g) apart is such, that when the cone
wheel (f) is in gear with the cone surface m (m¹), the cone wheel g, (g¹) is out
of gear with the cone surface n (n'), and vice versa; and also that both cone
wheels and g (f, g') may be simultaneously out of gear.
The details of the mechanism for moving the sleeves e, e' along the shafts c, c¹,
not being material to my invention, are omitted.
The above described mechanism operates in such a manner, that when the cone
wheel is put into gear with the cone surface m, the hoisting is performed at
the slower speed suitable for the heavier weights; whilst when the cone wheel f¹
is put into gear with the cone surface m', the hoisting is performed at the higher
'speed suitable for the lighter weights; also that when the cone wheel g is in gear
with the cone surface n, the lowering is performed at the slower speed suitable for
the heavier weights, whilst when the cone wheel g' is in gear with the cone
surface n', the lowering is performed at the higher speed suitable for the lighter
weights.
It will be evident that the differential cone gear arrangement above described
though forming a principal part of my invention as above described, may be
replaced by other differentially operating mechanism, and in such case the
arrangement of the first motor shaft driving from opposite ends thereof two
transverse shafts c, c' respectively, the latter operating by some differential
mechanism a common intermediate longitudinal shaft, still offers the great
advantage of occupying but a comparatively short depth below the traveller and
uniform overhang of the first motion shaft.
Having now particularly described and ascertained the nature of my said inven->
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In crane mechanism the employment of a duplicate arrangement of the
differential cone driving gear illustrated in Fig. 4 for driving a common shaft
such as the worm shaft h, in order to obtain two different speeds of hoisting and
two different speeds of lowering.
2. In crane mechanism the arrangement or combination of the first motion
shaft a driving at different speeds the transverse shafts c, c', with the differential
cone driving gear illustrated in Fig. 4 for the purpose of operating the worm
shaft has desired in two different directions and at two different speeds in each.
direction.
3. In crane mechanism the arrangement or combination of a transverse first
motion shaft a driving from opposite ends two transverse shafts c, cl, which latter
by means of suitable gearing operate a common intermediate shaft such as h in
two different directions and at two different speeds in each direction:

page_text: 4. My improved crane mechanism arranged, combined, and operating suo-
stantially as herein set forth and illustrated in Figs. 1 to 4 of the accompanying
drawings.
10th day of Febrnare 1896.
J. CLARK JEFFERSON,
30 Park Row, Leeds, Agent for Applicant.