IMPROVEMENTS IN HOISTING APPARATUS
Year: 1885

page_text: THOMAS HENRY WARD of the Firm of Lee Howl Ward & Howl Engineers
Tipton Staffordshire I do hereby declare the nature of my said invention for
IMPROVEMENTS IN HOISTING APPARATUS to be as follows:-
My Invention relates to improvements in that class of hoisting apparatus known
as the Hoisting Crab, but it is used in conjunction with chain only.
Such Crabs as referred to, are commonly provided with a barrel, around which
the lifting chain is coiled in the action of winding, & the other end of which after
passing above & over a pulley independently provided for the purpose, is attached
to the load directly, or else indirectly, through multiple or sheave blocks, supplied
for the purpose of obtaining extra leverage or purchase. As a consequence, the
height to which the load is capable of being lifted by such apparatus, is thereby
limitted by the diameter & the length of the barrel; involving practically, an
apparatus more costly, more bulky, heavier, & less compact, than might otherwise
be necessary, but for that barrel.
My Invention more particularly provides a remedy for this evil, & it further
relates to improvements connected with the brake or lowering gear, & likewise
other general improvements, thereby obtaining a very compact, cheap, neat, &
handy form of Crab; whether as arranged for the floor, the ground, or the platform;
or whether as fixed to the wall, the post, the pillar, or other suitable support.
In place of the above mentioned barrel upon which the chain is wound, I provide
a chain wheel only, such as one of the top sheaves of an ordinary Weston's
Differential pulley block, & like it, requiring that the chain used, shall be specially
made so as to gear into its teeth; which chain must embrace that wheel in a like
manner, & to a like extent about, that is, about half a circle, sufficient at least to
ensure that the chain is released from binding the teeth, on the back or far side of
the wheel; thereby enabling it to drop, or fall away again, from the wheel on that
side, instead of completing the coil.
Unlike Weston's however, this chain is inverted, that is, it passes & winds under
instead of over the pulley; consequently gravity tends to disengage it, & to avoid
so doing, I pass it over a guide preferably a loose roller, on the back side, provided
for that purpose, & allow it to hang loosely over the same.
A frame by preference of Cast iron, & of box section, is provided, the one end
of which, may be arranged for securing to the wall, floor, or other support; & the
other end by preference, may be opened so as to form a bifurcated frame. The
before mentioned chain wheel is keyed to a shaft, & carried in between the sides or
forks of such frame, by means of bearings on either side. By preference, one end
of this shaft projects outwards, beyond its bearing, & to it is keyed by preference
also, an internal spur wheel. Parellel with the said shaft, may be situated another,
having bearings provided for its reception in the frame, as in the former case, one
on either side; which shaft carries a fixed or solid pinion, gearing into the spur

page_text: wheel before mentioned, & is actuated by a winch handle or its equivelent, provided
for that purpose.
By preference a brake gear of a special nature is provided, for the purpose of
arresting automatically, the descent of the load when raised, thereby enabling the
handle to be released at will; & it is further provided for the purpose of obtaining
a more thorough, & a safer command when lowering.
It is applied in connection with the one, or the other, of the shafts, by preference
the pinion or first motion shaft, & it consists as follows as applied for example to
the pinion shaft.
The end of this shaft is screwed with a quick thread, preferably a double square
thread, & in a direction such, that in raising the load by rotating; the handle (which
is likewise screwed to correspond, serving the purpose of a nut) grips tightly in
between it, & a fast collar, (provided for that purpose on the shaft,) a disc, or roller,
identified as N° 1, & which is merely threaded loosely thereon; thereby rotating
handle, roller, shaft, & pinion as one solid piece.
From the near side of the said frame, a rigid projecting piece, serving the purpose
of an incline plane, overlaps this roller, with a clearance in between, & in such a
manner, that a small roller N° 2 which is loosely inserted between, drops by gravity,
& lies in contact with both N° I roller & that incline plane; constituting thereby
a rolling wedge, but acting as such, in the direction of lowering only.
When the handle is released, the suspended load tends to drag the said shaft
back, in the wedging direction, & is thereby retarded.
By rotating the handle in that same direction, the grip is released between N° 1
roller & the pinion shaft; & although that roller can never rotate in that direction,
on account of the roller wedge, yet the shaft, & the pinion can do so, but only at
the same time, & at the same speed of rotation, as that of the handle.
The pitch of the above mentioned screw, should be as quick as possible, so long
as there is sufficient grip for the chain-wheel to pick up the lead; otherwise if too
slow, it is difficult to release it as necessary, in the action of lowering.
It is immeterial as to whether there be one, two, or more shafts; but it is always
desirable that the brake gear shall be connected with the handle shaft, since the
strain upon it is least there.
By slight modifications, the chain-wheel, or the pinion as the case may be, may be
fixed to the shaft, & the handle screwed, or vice versa; the example as herein before
described, being identified as a case, where the pinion is fixed, & the handle screwed.
There are other modifications, some of which are inferior equivelents; as for
examples, as where the roller wedge is applied, to act internally, instead of
externally, upon the main roller; or again, where a ratchet, & detent or pawl,
serves instead of such rolling wedge. Or again where external spur gear, or bevel,
or even chain gear, serves instead of the internal spur gear. Further, where an
ordinary brake strap, or its equivelent serves in place of the one described, in which
case, it may be very advantageously applied, on the outside of the before mentioned
internal spur wheel.
But the most important modification of all, is one affecting the Brake-gear; in
which, the object is to provide for more rapid lowering; & it consists of merely
threading the chain wheel, or pinion as the case may be, loosely upon the shaft, &
gripping it tightly, in between the screwed handle, & the collar, in company with,
& in a similar manner to roller N° 1.
By unscrewing, & thereby releasing the grip upon it, it parts company with N° 1
roller; & unlike the latter, it rotates freely in the direction of lowering, by virtue
of gravity of the load, whilst the shaft, roller, & handle, remain stationary.
By screwing up again, the chain wheel is gripped tightly, & its descent arrested;
or it may be raised by further rotation in that direction.
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page_text: I, THOMAS HENRY WARD of the Firm of Lee Howl Ward & Howl Engineers
Tipton Staffordshire do hereby declare the nature of my invention for IMPROVE-
MENTS IN HOISTING APPARATUS and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement:-
My Invention relates to improvements in that class of hoisting apparatus known
as an hoisting crab, but capable of being used only with chain, & it has for its
chief objects the production of an apparatus which shall be on the whole more
compact & efficient, & which so far as regards the lowering gear shall be under
more thorough control, hence it is safer both as to life & property.
It is a self acting brake gear, which releases as the load is being raised, sustains
it afterwards, & only permits of lowering by winding backwards, in which case
a very slight effort is required, & as accelerated speed is impossible, the handle
stops even when suddenly released accidentally or otherwise, hence the safety as
before mentioned.
According to one simple arrangement of my invention, which for example I will
now describe, considering it to be by far the best, but which is capable of various
modifications without departure therefrom, I make it as follows.
Figure 1 represents in elevation such an apparatus arranged for bolting to a wall,
& Figure 2 is a sectional plan thereof on line 1 & 2 of Fig. 1, Figure 3 is a front
view, & Figure 4 is an outside plan, whilst Figure 5 represents the identical
arrangement but as suitable for the floor or ground rather than the wall.
Instead of an ordinary barrel I use a chain wheel A engaging & sustaining the
chain B by means of teeth A, cast thereon, after the manner as provided in a
Westons differential pulley block, which chain embraces the wheel in a like
manner, & to a like extent of about half a circle or sufficient at least to ensure its
release on the opposite side.
Unlike Weston's however this chain is inverted, that is it. passes & winds
under instead of over the wheel A consequently gravity tends to disengage it, & to
avoid so doing I pass it over a loose roller O on the back side provided for that
purpose, & allow it to hang loosely over the same.
A cast iron box or pillar section frame is provided D the one end of which is
suitable for securing to to the wall, ground, or other support, & the outer end
opened or otherwise provided for the reception of the Chain wheel A &.
This chain wheel A is keyed to a shaft E & carried in between the sides or fork
of such frame D by means of bearings E, on either side. One end of this shaft
projects outwards as shown at E, beyond its bearing, & to it is keyed an internal
spur wheel E3. Parrellel with this shaft E is situated another shaft F having
bearings provided for its reception in the frame as in the former case one on either
side, which shaft F carries a fixed pinion F, gearing into the spur wheel E, & is
actuated by a winch handle G or its equivelent provided for that purpose.
The brake gear is provided in connection with one or other of the shafts, but is
herein described as connected to the first motion shaft F as most suitable.
The end of this shaft F.is screwed in a direction such that in raising the load by
rotating the handle G (which is likewise screwed to correspond serving the purpose
of a nut) grips tightly in between it & a fast collar H (provided for that purpose
on the shaft) a friction cone J, which is merely threaded loosely thereon, & which

page_text: engages the fast collar H, which collar is coned likewise to suit, thereby rotating
the handle G friction cone J collar H pinion F, & shaft as one piece (when the load
is being raised).
This friction cone J is also provided with teeth J₁ engaging with a pawl K, in
such a manner & direction that its rotation is possible in the direction of raising
only.
When the handle is released, the suspended load tends to drag the shafts F
backwards, but as the friction cone J cannot rotate in that direction, & is firmly
gripped between the cone collar H & the handle G, it prevents thereby the descent
of the load.
By rotating this handle G in the direction of lowering, this grip is released, &
.although the cone ratchet wheel J can never rotate in that direction, yet the
shaft F within can do so, but only at the same time, & at the same speed of
rotation as that of the handle.
Instead of the friction cone being provided with teeth & being retarded in the
lowering direction only, by the pawl engaging therein, its periphery may form a
plain roller, & be retarded in a like manner, by a small rolling wedge jamming
between it & an overhanging bracket cast or otherwise fixed to the frame, the
inner surface or rolling path of which forms a short incline plane for that purpose.
The angle of the friction cone on the one hand must be relative to the pitch of
the screw, sufficient to avoid slipping, yet capable of being released without
jamming; whilst the angle of the screw on the other hand relative to the friction
cone must be sufliciently slow to satisfy the cone gripping, & yet sufficiently great
to ensure an easy release.
Having now particularly described & ascertained the nature of my said
Invention, & in what manner the same is to be performed, I declare that what
I claim is
(1.) In chain crab hoisting apparatus, the arrangement & combination of parts
constituting the several constructions of my apparatus, substantially as herein
before described & illustrated in Figures 1, 2, 3, 4, & 5 of the accompanying
drawings..
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(2.) In chain crab hoisting apparatus, the mode of arranging the brake
the extreme end of the shaft F after passing through the bearings, substantially as
herein before described & illustrated more especially in Figure 2 of the drawings.
(3.) In chain crab hoisting apparatus, the combination of the pinion F₁, screwed
shaft F, the fixed cone collar E, the loose cone & ratchet wheel J, & pawl K (or
their equivelents if rolling wedge) & handle G substantially as herein before
described & illustrated in the accompanying drawings.
(4.) In chain wall crab hoisting apparatus, the arrangement of parts whereby
the chain & chain wheel face at right angles to the wall rather than parellel
thereto, substantially as herein before described & illustrated in the accompanying
drawings.
(5.) Utilizing the idle pin which carries the idle or guide wheel C, as a fulcrum
for the pawl, substantially as herein before described & illustrated in the accom-
panying drawings.
(6.) In chain crab hoisting apparatus the combination of the inverted chain
wheel A, the idle or guide wheel C, & the box or pillar section frame D substan-
tially as herein before described & illustrated in the accompanying drawings.
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