Improvements in Lifts, Hoists, and the like.
Year: 1888

page_text: Date of Application, 26th Nov., 1888
Complete Specification Left, 16th Aug., 1889-Accepted, 21st Sept., 1889
PROVISIONAL SPECIFICATION.
Improvements in Lifts, Hoists, and the like.
We, HENRY CLAUDE WALKER and ROBERT FALKLAND CAREY both of the
Newington Iron Works, Falmouth Road, London S.E. Engineers do hereby declare
the nature of this invention to be as follows:-
Our invention relates principally to that class of lifts and hoists called self-
sustaining in which the load is automatically held suspended when the motive power
is withdrawn but is released by the reversal of the direction of the motive power and
allowed to run back as long as this reverse motion is continued, and at the same
speed. Our invention is also applicable to cranes, winches, and other kinds of lifting,
hauling, and winding machinery.
The object of our invention is to provide a self-sustaining hoist or the like to fulfil
the above conditions whether the pull of the load tends to revolve the machinery
in one direction or the other, and to lower the load evenly and without the jerky
motion sometimes present in those forms of self-sustaining hoists in general use.
also in some cases provide a secondary means of lowering the load independently of
the reversed direction of the motive power.
We
Our Invention consists principally of a driving wheel to which the motive power is
applied, a lifting wheel or drum to which the load is suspended, a brake ring
which in its normal condition is prevented from revolving by being held by a
brake strap or other convenient mechanism or coupled up to a suitable fixed support,
and the arresting mechanism which consists of one or more cams which revolve
with the lifting wheel and engage with the brake ring aforementioned.
The driving wheel may be of any convenient shape to suit the medium by means
of which the motive power is transmitted. It may for instance have a V-groove
to suit a rope or chain or have teeth or it may be replaced by a crank when it is
desirable to apply the motive power direct. This driving wheel is secured to a shaft
running loose in suitable bearings and is provided with two sets of projections or
other media one set being for the purpose of driving the lifting wheel and the
other set for releasing the cams. These projections may be formed either upon the
driving wheel itself or upon a disc or other suitable appliance keyed on to the same
shaft or to other shafts receiving direct motion.
The lifting wheel may have a suitable groove or grooves for a rope or chain, or a
drum or barrel may be used in place of the wheel. This wheel or barrel may be
mounted on a separate shaft and driven by gearing from the driving wheel or it may
be arranged on the same shaft but not secured thereto, formed with the wheel or
barrel or secured thereto is a sleeve carrying the arresting mechanism and having a
set of projections or other media for engaging with the projections or other media
aforementioned connected with driving wheel such media having sufficient play
between them to allow the driving wheel a little independent movement for the
purpose of releasing the cams.
The arresting mechanism consists of one or more cams or brake blocks the faces of
which act upon the inner periphery of the brake ring. These cams are fulcrummed
on a sleeve connected to or forming part of the lifting wheel or drum and revolve
with it. They are arranged sufficiently close to the brake ring to cause sufficient
friction to put them into action and are of such a configuration as will allow them to
free themselves when the sleeve to which they are attached is revolved in the reverse
direction to the one which put them into action and they are released by the arms
with which they are provided coming into contact with the projections aforementioned
connected with the driving wheel. These arms have sufficient play between the said
projections to allow them to come into action. For light loads only one cam is

page_text: necessary so that in this case when the cam comes into action with the brake ring the
reaction on the fulcrum causes that portion of sleeve diametrically adjacent to the
said fulcrum to press against the shaft and so arrest, its movement. For heavy loads
two or more cams are used and as in this case they are preferably arranged at equal
distances from each other their reactions would be rendered non-effective on the shaft.
In this case the cams instead of being fulcrummed direct on the sleeve are each
fulcrummed on a rubbing piece which revolves with the sleeve but is pressed on the
shaft when the cams come into action. The same effect may be produced by doing
away with the rubbing pieces and arranging the cams at different distances from each
other so as to throw the centre line of sleeve away from the axis of shaft when the
cams come into action.
The action of a hand power lift of our invention is as follows:-
Suppose the motive power to be withdrawn and the load to be hanging from the
lifting wheel. The weight of the load acting upon the lifting wheel tends to revolve
the whole of the moveable parts equally in a direction the reverse of the one taken
in lifting the load. The cams however work sufficiently close to the brake ring to
cause a friction between them and by retarding the motion of the cams cause them to
press against the inside periphery of brake ring and so set up sufficient friction to
prevent the load descending any further.
The load is now suspended. To lower the load the driving wheel must be kept in
advance of the lifting wheel to the extent of the independent action allowed between
the projections on sleeve and those connected with the driving wheel this inde-
pendent action being sufficient to allow the cams to be released by means of their
arms coming into contact with the projections connected with driving wheel.
Should the load make the lifting wheel gain on the driving wheel the cams again
come into action and by retarding the motion of lifting wheel cause the load to
descend regularly according to the speed of driving wheel.
When the load is being made to descend quickly by means of the driving wheel
and the motive power is suddenly withdrawn, sufficient impetus has been given to
the driving wheel to cause it to continue to revolve for some little time before it
comes to rest. This is found in practice to give trouble by causing the load to descend
in jerks as the load is arrested by cams and released in turn by the driving wheel.
In the apparatus of our invention this is obviated by the means aforementioned for
arresting the motion of the driving wheel by the cams at the same time as they
arrest the lifting wheel.
In cases where it is considered desirable to be able to lower the load independently
of the driving wheel we apply a mechanism such as a brake strap with suitable levers
to prevent the brake ring revolving under ordinary conditions but may be released
or arrested at will, or we may attain the same end by fitting a sliding clutch on the
shaft or some other arrangement by means of which the cams may for the time be
rendered non-effective.
We may also in some cases fulcrum the cams directly on the lifting wheel or drum
instead of on a sleeve connected to it.
Dated this 26th day of November 1888
HENRY C. WALKER.
ROB. F. CAREY.
COMPLETE SPECIFICATION.
Improvements in Lifts, Hoists, and the like.
We, HENRY CLAUDE WALKER and ROBERT FALKLAND CAREY both of the
Newington Iron Works, Falmouth Road, London, S.E. Engineers do hereby declare 5
the nature of this Invention and in what manner the same is to be performed to
be particularly ascertained and described in and by the following statement :-
Our invention relates principally to that class of lifts and hoists called self-sustaining
in which the load is automatically held suspended when the motive power is withdrawn
but is released by the reversal of the direction of the motive power and allowed to 5

page_text: run back as long as this reverse motion is continued, and at the same speed. Our
invention is also applicable to cranes, winches, and other kinds of lifting hauling and
winding machinery.
The object of our invention is to provide a self-sustaining gear to fulfil the above
conditions whether the pull of the load tends to revolve the machinery in one direction
or the other, and to lower the load evenly without the jerky motion common to the
self-sustaining hoists in general use. We may also provide a secondary means of
lowering the load, to act independently of the reversed direction of the motive
power.
Our invention consists principally of a driving wheel to which the motive power is
applied, a lifting wheel or drum to which the load is suspended, a brake ring which in
its normal condition is prevented from revolving by being held by a brake strap or
other convenient mechanism or coupled up to a suitable fixed support, and the
arresting mechanism which consists of one or more cams which revolve with the
lifting wheel and engage with the brake ring aforementioned.
The driving wheel may have a V-groove to suit a rope or chain or have teeth or it.
may be replaced by a crank when desirable. This driving wheel is mounted on a shaft
and has two sets of projections or other media one set being for the purpose of
driving the lifting wheel and the other set for releasing the cams. These projections
may be formed on the driving wheel itself or upon a disc or other appliance
connected therewith.
The lifting wheel may be similar to the driving wheel or a drum or barrel may
be substituted. This wheel or barrel may be mounted on a separate shaft and
Formed
driven by gearing from the driving wheel or it may be on the same shaft.
with it or connected thereto is a sleeve carrying the arresting mechanism and having
a set of projections or other media for engaging with the projections or other media
connected with driving wheel such media having sufficient play between them to allow
the driving wheel a little independent movement for the purpose of releasing the
cams.
The arresting mechanism consists of one or more cams or brake blocks the faces of
which act upon the inner periphery of brake ring. These cams are fulcrummed on
the sleeve aforementioned and revolve with it. They are arranged sufficiently close
to the brake ring to cause sufficient friction to put them into action and are of such
a configuration as will allow them to free themselves when the sleeve to which they
are attached is revolved in the reverse direction to the one which put them into action
and they are released by their arms coming into contact with the projections afore-
mentioned connected with the driving wheel. These arms have sufficient play
between the said projections to allow them to come into action. For light loads it is
only necessary to use one cam which when it comes into action with the brake ring
will re-act on the fulcrum and cause the sleeve to press against the shaft. For
heavy loads two or more cams may be used arranged preferably at equal distances
from each other and as in this case their re-actions combined on the sleeve would
neutralise each other they are each fulcrummed on a separate rubbing piece which
revolves with the sleeve but may be pressed on the shaft. The same effect could be
produced by placing the cams at different distances from each other.
In the accompanying drawings the same letters indicate the same parts and
figs. 1, 2, 3, 4 & 5 show one form of our apparatus, fig. 6 a modified form and fig. 7
an adaptation, figs. 8 and 9 also show modifications.
Fig. 1. is a sectional elevation, fig. 2 a sectional elevation on xx fig. 1. looking
in the direction of lifting drum, and fig. 3 a sectional elevation on y. y fig. 1 looking
in the direction of driving wheel. Fig. 4 is a plan view of sleeve detached and
fig. 5. a perspective view of one of the cams.
A is a wheel driven by the hand rope a and keyed to spindle B which runs in
suitable bearings. C is the lifting drum keyed to sleeve D which runs loose on
spindle B and has a gab d' which engages with gab e¹ on driving plate. E is a
driving plate keyed to spindle B and provided with slots e to engage with cam arms

page_text: and gab e¹ to engage with sleeve D. The cams F have arms f¹ and are pivotted at f
to rubbing pieces G which slide loosely in slot d in sleeve. H is a brake ring running
loosely on sleeve D but ordinarily held by brake strap I and lever i.
The action of this apparatus is as follows:-
Suppose the motive power to be withdrawn and the load to be hanging from the
lifting drum. The weight of the load acting upon this drum tends to revolve the
whole of the moveable parts equally in a direction the reverse of the one taken in
lifting the load. The cams however work sufficiently close to the brake ring to cause
a friction between them and by retarding the motion of the cams cause them to press
against the inside periphery of brake ring and so set up sufficient friction to prevent
the load descending any further. The load is now suspended. To lower the load the
driving wheel must be kept in advance of the lifting wheel to the extent of the
independent action allowed between the projections on sleeve and those connected
with the driving plate this independent action being sufficient to allow the cams to
be released by means of their arms coming into contact with the ends of slot on
driving plate. Should the load make the lifting drum gain on the driving wheel
the cams again come into action and by retarding the notion of lifting wheel cause
the load to descend regularly according to the speed of driving wheel.
When the load is being made to descend quickly by means of the driving wheel
and the motive power is suddenly withdrawn, sufficient impetus has been given to
the driving wheel to cause it to continue to revolve for some little time before it
comes to rest. This is found in practice to give trouble by causing the load to
descend in jerks as the load is arrested by cams and released in turn by driving
wheel. In the apparatus of our invention this is obviated by the means afore-
mentioned for arresting the motion of the driving wheel by the cams at the same
time as they arrest the lifting wheel.
Fig. 6 shows an arrangement with one cam only, the action being as previously
described.
Fig. 7 shows a modified form of cam adapted as a self-sustaining brake. In this
case the cam J is fulcrummed on a stationary point and the brake ring K, which is
connected to the lifting drum, revolves freely in the direction shown by arrow but is
immediately arrested if it attempts to revolve in the reverse direction.
Figs. 8 and 9 show a modification. The brake ring H and cams F are the same
as before. The sleeve D is in this case keyed on to shaft B which operates the lifting
drum although it might be connected direct as before. The sleeve is driven by
projection which engages with a similar projection on a disc L which revolves
freely on shaft B. The hand-lever M also runs loose on shaft and drives the
apparatus by levers N pivotted at n to the disc L and engaging with cam arms f¹.
The action of the cams in this modification is similar to those before described
with the exception of the method of releasing them by means of pivotted levers N
which method is found to give excellent results.
In this modification a hand lever is shown as the operating medium but any other
lever or wheel might be substituted.
Having now particularly described and ascertained the nature of our inven-
tion and in what manner the same is to be performed, we wish it to be particularly
understood that we do not bind ourselves to the exact details illustrated and described,
but we do declare that what we claim is―
1. The self-sustaining gear substantially as shown in figures 1, 2, 3, 4 and 5 and
as hereinbefore described.
2. The modification of this gear substantially as shown in fig. 6 and as herein before
described.
3. In self-sustaining gear for hoists and the like, the employment of one or more
cams or brake blocks acting upon the inner periphery of a brake ring and released 'by
projections or other media operated by the driving mechanism substantially as
described.

page_text: 4. In self-sustaining gear for hoists and the like, the combination of the cams
or other sustaining gear with the rubbing-pieces or equivalent for arresting the
motion of driving wheel substantially as and for the purposes set forth.
Thaind thin 21nt dove of T-1-1900
HENRY CLAUDE WALKER.
ROBERT FALKLAND CAREY.