Year: 1886

page_text: I, ALEXANDER GRAFTON of 113 Cannon Street, in the City of London, Engineer,
do hereby declare the nature of this invention to be as follows:-
This Invention relates to improvements in the construction of traveller crabs
and specially to the double purchase lifting gear- and to the longitudinal travelling
and transverse traversing gear on the crab, and is chiefly applicable to such
travellers as are worked by hand although it may also be applied to power driven
travellers. According to my invention the barrel and its gear wheel are arranged
at the upper part of the crab and the handle shaft and pinion gearing for working
the barrel are placed below the barrel at a level or nearly so with the axles of the
travelling wheels of the crab and in such close proximity to one of them, that the
said axle may be utilized as a second motion shaft in the train of gearing by
placing upon it a wheel and pinion which turn freely as one on the axle, and are
free to slide on the axle for the purpose of throwing the pinion in or out of gear,
with the barrel wheel, the handle shaft being also adjustable longitudinally for the
purpose of throwing its pinion into or out of gear with the second motion wheel or
the barrel wheel as the case may be. I further utilize this axle as a shaft for
applying the break to the barrel and for this purpose I attach to the axle, a short
lever to which the break strap is connected and I prolong the axle through the
travelling wheel and provide it with a hand lever. The other axle I make tubular
and attach a band wheel directly to it in order to obtain the cross traversing
motion. Through this hollow axle I pass a handle shaft, which is geared by bevel
gear with a tumbler shaft, mounted alongside the cross girders and attached to
the longitudinal travelling wheels as usual. The bevel wheel through which the
tumbler shaft passes is carried by a quill which as well as the wheel is free to slide
upon the tumbler shaft and is mounted in a tubular bearing which is supported by
a prolongation of the handle shaft that passes through the hollow axle and upon
which prolongation the other bevel wheel is keyed.
The advantages I obtain by this arrangement are a considerable gain in head
room for working, fewer shafts and bearings, and hence a great economy in first
cost, and in power consumed by friction.
2 T
1000
A. GRAFTON.
By A. M. & W Clark, Patent Agents,
53, Chancery Lane, London,

page_text: I ALEXANDER GRAFTON, of 113 Cannon Street, in the City of London, 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:—
This invention relates to the construction of hand-power traveller-crabs and
especially to improvements in the double-purchase lifting, the longitudinal-
travelling, and the transverse-traversing gears, whereby the number of shafts
and bearings is reduced, with a corresponding economy in first cost and in power
consumed by friction, and whereby a considerable gain in head room for working
the crab is effected, which is all-important when over-head space is limited.
According to my invention, the handle, or first-motion, shaft and gearing for
working the barrel are placed below, instead of above the barrel and nearly at a
level with, and in proximity to, one of the axles of the traversing wheels of the
crab, and the said axle is utilized as the axis of the second-motion gear through
which the first-motion shaft is geared with the barrel when double-purchase is
required. The said axle is further utilized as a shaft for applying the brake to the
barrel. The axle of the other pair of traversing wheels is tubular, and within it
is mounted the first-motion or hand shaft of the longitudinal-travelling gear the
suid first-inotion shaft being geared direct to the tumbler-shaft of the longitudinal-
travelling wheels without intermediate gear. A hand-wheel is applied directly to
the hollow axle for obtaining the transverse-traversing motion.
In this manner all the hand operated shafts are arranged considerably below the
level of the barrel axis, so as to be easily operated simultaneously or separately by
a man standing at a lower level than the rails on which the crab travels, so that
no overhead room is required for working.
Reference is to be had to the accompanying drawings forming part of this
specification, wherein figure 1 represents a front elevation. Figure 2 a side
elevation and Figure 3 a half plan of the improved crab, the figures being partly
in section. Figure 4 is a separate view of the wheel axle in which is mounted the
first or hand motion shaft of the longitudinal-travelling motion, the gear connecting
this shaft with the tumbler-shaft being in section.
The same letters of reference indicate the saine parts in all the figures.
A, is the axis of the barrel B fixed in bearings at the upper part of the frame C,
of the crab. D, E, are the axles of the two pairs of traversing wheels D' E¹ of the
crab, they are journalled in the frame C. F, is the first-motion or handle shaft for
working the hoisting barrel B. It is journalled in the frame C in such proximity
to the lower part of the barrel, and to the axle D that a pinion f upon it may be
made to gear either directly with the gear wheel 6 of the barrel for single-purchase,
or indirectly as shewn in the drawings through a combined spur wheel G and
pinion g for double-purchase. The wheel G turns as one with the pinion g loose

page_text: upon the axie D of the combined wheel and pinion being free to slide as well as to
rotate on the axle and the shaft F being longitudinally adjustable in its bearings
for the purpose of bringing either the single- or double-purchase gear into action as
required. The adjustment of the combined wheel and pinion is effected by hand
and the wheel G is retained in gear with the pinion f and the pinion g with the
barrel-wheel b, by means of a sleeve g¹ which is slid upon the axle, and is locked
when the intermediate gear G, g, is in operative position, by means of a bayonet
slot g engaging with a stud on the axle.
To enable the axle D to be utilized as the brake shaft, the traversing wheels are
loose upon it and it is prolonged through one of them and has a hand-lever h fixed
on the prolonged end for applying the brake. H, is the brake strap which is made
fast at one end to the frame C, and is connected at the other end to a short lever h¹
fast on the axle.
The other pair of traversing wheels are fast on their axle E, which has a hand-
wheel E fixed upon a prolongation of the axle in order to obtain the transverse
traversing motion of the crab.
This axle is tubular and in it is mounted the first-motion or hand shaft K of the
longitudinal travelling gear for moving the main carriage along its rails. This
shaft is provided with a handle K₁ for operating it, the handle turning in front of
the hand wheel E', and the shaft is geared at its opposite end directly with the
tumbler-shaft L (to which the longitudinal-travelling wheels of the cross girders
or carriage are attached as usual) the gear connecting these two shafts being
supported by the first-motion shaft and being free to swivel thereon so as to adapt
itself to the direction of the tumbler-shaft should the latter sag between its points
of support. This gear consists of a bevel wheel k keyed on the shaft K and
gearing with another bevel wheel m fast on the quill M which is free to slide upon
the tumbler-shaft L but turns therewith, the quill being mounted in a tubular
T shaped bearing N which is pivoted upon a prolongation of the shaft K, so that
the quill M and wheel m are free to swivel about the axis of said shaft without
disengaging the bevel gear.
I am aware that the first-motion shaft of the longitudinal-travelling gear has
already been mounted within a hollow shaft at the upper part of the crab, but
such hollow shaft has been part of the gear and not the axle of the traversing
wheels.
The rails upon which the crab is traversed are shown, but not the cross girders
or longitudinally travelling carriage which carry them. The various handles for
operating the crab are within easy reach of the workman, standing on a flying
platform (not shown) carried by the said cross girders on carriage.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
1. A traveller-crab in which the intermediate or second-motion wheels of the
hoisting gear turn about the axle of one pair of traversing wheels as a centre,
substantially as and for the purpose specified.
2. In a traveller-crab in which the axle of one pair of traversing-wheels is free
to turn loose within the wheels, the combination with this traversing-wheel axle of
the brake-strap and of means for operating it, substantially as specified.
3. A traveller-crab in which the intermediate or second-motion wheels of the
hoisting gear turn about the axle of one pair of traversing wheels as a centre and
in which the said axle is loose within the wheels and is combined with the brake
strap, and means for operating it whereby the axle is utilized both as the axis for
the second-motion gear and as a brake-shaft, substantially as specified.
4. A traveller-crab in which the first-motion, or hand, shaft of the longitudinal-
travelling mechanism is mounted within a tubular, traversing-wheel, axle and
gears direct with the tumbler-shaft for producing longitudinal-travelling movement,
substantially as specified.

page_text: 5. A traveller-crab in which the first-motion shaft of the longitudinal-travelling
mechanism is mounted within a tubular axle having a pair of traversing-wheels
fast upon it, and provided with a hand wheel for producing the cross-traversing
motion.
6. A traveller-crab in which the shafts and gear of the hoisting, brake, cross-
traversing and longitudinal-travelling, mechanism are combined with the traversing-
wheel axles and arranged at the lower part of the crab, substantially as herein
described and illustrated in the drawings.