IMPROVEMENTS IN LIFTING OR HOISTING MACHINERY
Year: 1884

page_text: We JOHN MARSH DAY, WILLIAM ROBERT GREEN, HENRY CLAUDE WALKER
and ROBERT CAREY, all of Falmouth Road in the County of Surrey, Engineers,
do hereby declare the nature of our invention for IMPROVEMENTS IN LIFTING
OR HOISTING MACHINERY" to be as follows:
Our invention relates to lifting or hoisting machinery in which it is required
that the load which is being lifted or lowered shall be automatically sustained
whenever power is not being applied, and it has for its object improvements in the
construction and arrangement of such machinery by which the load is automatically
held in any position and prevented from running down or back when the power is
not being exerted, the lowering of the load being effected by reversing the direction
in which the power is applied to raise it.
In order to put our invention in operation, we cause a spindle or shaft of
suitable size and strength to revolve by any convenient means in bearings suitably
supported and fixed. Upon the shaft we fix a short feather or key, and round the
shaft where this feather is fixed we fit two loose segments or friction pieces of such
size and shape that their outer circumference is cylindrical whilst each piece where
they join has a notch cut out of its end so as to pass freely over the feather the
notch so formed being of such length that the segments may revolve for a short
distance round the shaft before they are stopped by the feather against the ends of
the notch. The other or opposite ends of the segments are sufficiently far apart to
allow the end of a square bar parallel with the shaft to be inserted between them.
An outer ring of sufficient strength is fitted freely round the segments arranged
upon the shaft as described, and this ring is firmly attached by a radial arm or
other convenient means to the framing of the machinery, or other support, so that
it cannot revolve with the shaft and segments.
The feather upon the shaft extends for a sufficient distance beyond the segments
to drive a pinion, wheel, barrel, or other device by which the load is raised in the
usual way, and this pinion or other device has a key way at its centre exactly
corresponding with the size of the notch formed in the ends of the segments and
fitting over the feather as already described, so that the feather comes in contact
with the end of one of the segments at one end and with the end of the keyway in
the pinion at its other end, and in whichever direction the shaft is made to revolve
[Pico 671

page_text: the feather upon it will carry round the pinion or barrel and the segments in the
same direction and in the saine relative positions.
The square bar the end of which is inserted between the opposite ends of the
segments as above described is then turned at right angles so as to project about
radially from the shaft, its outer end being held loosely between two studs or
projections upon the end of the pinion or barrel.
So long, therefore as it projects radially from the shaft its square end fits freely
between the ends of the segments, but if it be turned slightly out of its radial
position to the right or left, its square end is turned so that its opposite corners
separate the segments and join the latter sufficiently tightly in the ring which
surrounds them so that it prevents them from revolving.
So long therefore as the rotation of the shaft by the power applied to it keeps
the bar in its radial position the segments, bar, and pinion or barrel, are all turned
round together freely, but when the power turning the shaft is removed the barrel
or pinion is pulled backward by the load and the shaft being free to move, the bar
is slightly turned backward out of its radial position and the edges of its square
end pressing in opposite directions against the segments causes them to bite against
the inside of the fixed ring and the barrel or pinion is thus prevented from running
back, whilst the heavier the load the more firmly are the segments forced against
the ring.
The square end of the bar will operate in the same way in whichever direction
it is turned, and the machinery is therefore applicable to double lifts or to lifts
having a balance weight heavier than the cage, or to cases in which the load
to be lifted may sometimes be upon one side of the barrel and sometimes on the
other side.
In some cases we use the following modified arrangement, in order to avoid the
loss of leverage in lowering the load for which purpose in the arrangement just
described it is necessary to bring the lever back to its radial position by the pressure
of the feather on the shaft forcing the segments against the twisted edges of the
square end of the bars until the bar is brought to its radial position against the load
pressing upon its long arm. We firmly fix upon the shaft a collar of sufficient
diameter having a projection upon one side engaging between two corresponding
projections upon the barrel or pinion so that it will drive the latter in whichever
direction the shaft is made to revolve, a little play being left between them so that
the shaft can move slightly round in either direction before the barrel or pinion
begins to be driven by it.
Two segments fit round the collar with a fixed ring as in the arrangement first
described, the end of a square bar being inserted between the ends of the segments
in the same way. Instead however of the outer part of the bar projecting radially
from the shaft only, it has also a second arm projecting inwardly to the shaft by
the side of the fixed collar, the entire bar being therefore T-shaped.
The arm projecting outward is held loosely between two studs or projections
upon the barrel or pinion, whilst the arm projecting inward fits between two studs
or projections upon the side of the fixed collar, one or other of which just touches
the arm when the projection formerly mentioned engages with one or other of the
corresponding projections upon the barrel or pinion. When therefore the power is
withdrawn from the shaft and the load attempts to run back the square end of the
lever is twisted between the ends of the segments which are forced apart and hold
the load by their friction against the fixed ring as in the arrangement first
described; whilst when it is required to lower the load the shaft is turned in the
opposite direction and one of the studs or projections upon the fixed collar comes
in contact with the arm projecting inward and forces it back to its radial position,
thus releasing the segments and allowing the load to descend so long as power is
applied to make the shaft revolve, but retaining the load in its position directly
the power is withdrawn from the shaft.

page_text: Our invention may be modified in its details to suit the varying circumstances in
which it is to be applied. For instance the bar may be straight and arranged to
lie parallel with the shaft, one end being inserted between the segments as
described, and its other end being operated by the barrel or pinion which is kept
at a sufficient distance from the segments and fixed ring to give the requisite bite,
the bar lying parallel with the shaft whilst power is being applied to the latter, but
being slightly turned to the right or left and separating the segments when the
power is removed so that the load is held.
Or a wedge shaped bar may be used, and a ring or part of a ring instead of
the segments, so that when moved slightly in either direction the wedge forces the
inner ring against the outer one, and gives the necessary friction to hold the load.
The end of the bar inserted between the segments as described may be elliptic or
other suitable shape instead of being square as described.
D
71

page_text: We, JOHN MARSH DAY, WILLIAM ROBERT GREEN, HENRY CLAUDE WALKER,
and ROBERT CAREY, all of Falmouth Road, in the county of Surrey, Engineers,
do hereby declare the nature of our invention for "IMPROVEMENTS IN LIFTING
OR HOISTING MACHINERY and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement:—
"
Our invention relates to lifting or hoisting machinery of the kind known as self
sustaining in which it is required that the load which is being lifted or lowered
shall be sustained whenever power is not being applied, and it has for its object
improvements in the construction and arrangement of such machinery by which the
load is automatically held in any position and prevented from running down or
back when the power is not being exerted, the lowering of the load being effected
by reversing the direction in which the power is applied to raise it.
In the accompanying drawings, which are in illustration of our invention,
Figure 1 is a side view, figure 2 an end view, and figure 3 a plan of part of a lift
having our invention applied to it.
a is a spindle or shaft of suitable size and strength revolving in bearings b, b¹,
suitably supported and fixed as shewn at c.
Upon the shaft a we fix a short feather or key d, and round the shaft where this
feather is fixed we fit two loose segments or friction pieces e, e, of such size and
shape that their outer circumference is cylindrical whilst each piece where they
join has a notch cut out of its end so as to pass freely over the feather d the notch f
so formed being of such length that the segments may revolve for a short distance
round the shaft a before they are stopped by the feather d against the ends of the
notch (as shewn on a larger scale at figure 14). The other or opposite ends of the
segments e, e, are sufficiently far apart to allow the end of a square bar g parallel
with the shaft to be inserted between them. An outer ring h of sufficient strength
is fitted freely round the segments e, e, arranged upon the shaft a as described, and
this ring his firmly attached by a radial arm i or other convenient means to the
framing c of the machinery or other support, so that it cannot revolve with the
shaft and segments.
The feather & upon the shaft extends for a sufficient distance beyond the
segments e, e, to drive a pinion, wheel, barrel, or other device by which the load
is raised in the usual way (as shewn in figure 3), and this pinion or other device has
a keyway at its centre exactly corresponding with the size of the notch f formed in
the ends of the segments e, e, and fitting over the feather d as already described, so
that the feather comes in contact with the end of one of the segments at one end
and with the end of the keyway in the pinion k at its other end, and in whichever
direction the shaft is made to revolve the feather upon it will carry round the
pinion or barrel k and the segments e, e, in the same direction and in the same
relative positions.
The square bar the end of which is inserted between the opposite ends of the
segments as above described is then turned at right angles so as to project about
radially from the shaft, its outer end being held loosely between two studs or
projections, l, upon the end of the pinion or barrel k.
So long, therefore as it projects radially from the shaft its square end fits freely
between the ends of the segments e, e, but if it be turned slightly out of its radial
position to the right or left, its square end is turned so that its opposite corners
separate the segments and jam the latter sufficiently tightly in the ring which
surrounds them so that it prevents them from revolving.

page_text: So long therefore as the rotation of the shaft a by the power applied to it keeps
the bar g in its radial position the segments e, e, bar g, and pinion or barrel k are
all turned round together freely, but when the power turning the shaft is removed
the barrel or pinion is pulled backward by the load and the shaft a being free to
move, the bar g is slightly turned backward out of its radial position and the edges
of its square end pressing in opposite directions against the segments e, e, causes
them to bite against the inside of the fixed ring h and the barrel or pinion is thus
prevented from running back, whilst the heavier the load the more firmly are the
segments forced against the ring.
The square end of the bar
will operate in the same way in whichever direction
it is turned, and the machinery is therefore applicable to double lifts or to lifts
having a balance weight heavier than the cage, or to cases in which the load to be
lifted may sometimes be upon one side of the barrel and sometimes on the
other side.
In some cases we use the following modified arrangement, (shewn applied to a
hoisting pulley in figures 4, 5, and 6, and to a barrel in figures 7 and 8) in
order to avoid the loss of leverage in lowering the load for which purpose in the
arrangement just described it is necessary to bring the lever or bar g back to its
radial position by the pressure of the feather on the shaft a forcing the segments
against the twisted edges of the square end of the bar, until the bar is brought to its
radial position against the load pressing upon its long arm. We firmly fix upon the
shaft à a collar m of sufficient diameter having a projection upon one side engaging
between two corresponding projections upon the barrel or pinion le so that it will
drive the latter in whichever direction the shaft a is made to revolve, a little play
being left between them so that the shaft can move slightly round in either
direction before the barrel or pinion begins to be driven by it.
Two segments e, e, fit round the collar within a fixed ring has in the
arrangement first described, the end of a square bar being inserted between
the ends of the segments e, e in the same way. Instead however of the outer part
of the bar projecting radially from the shaft only, it has also a second arm g¹
projecting inwardly to the shaft a by the side of the fixed collar m, the entire bar
being therefore T-shaped. The arm projecting outward is held loosely by a stud or
projection upon the barrel or pinion, whilst the arm projecting inward fits between
two studs or projections o, o, upon the fixed collar m one or other of which just
touch the arm g¹. When therefore the power is withdrawn from the shaft a and
the load attempts to run back the square end of the lever g is twisted between the
ends of the segments e, e, which are forced apart and hold the load by their friction
against the fixed ring has in the arrangement first described; whilst when it is
required to lower the load the shaft is turned in the opposite direction and one of
the studs or projections o, o, upon the fixed collar m comes in contact with the
arm g¹ projecting inward and forces it back to its radial position, thus releasing
the segments e, e, and allowing the load to descend so long as power is applied to
make the shaft revolve, but retaining the load in its position directly the power
is withdrawn from the shaft.
Our invention may be modified in its details to suit the varying circumstances
in which it is to be applied. For instance the bar may be straight and arranged
to lie parallel with the shaft, one end being inserted between the segments as
described, and its other end being operated by the barrel or pinion which is kept
at a sufficient distance from the segments and fixed ring to give the requisite bite,
the bar lying parallel with the shaft whilst power is being applied to the latter, but
being slightly turned to the right or left and separating the segments when the
power is removed so that the load is held.
Or a wedge shaped bar may be used and a ring or part of a ring instead of the
segments, so that when moved slightly in either direction the wedge forces the
inner ring against the outer one, and gives the necessary friction to hold the load.
The end of the bar inserted between the segments as described may be elliptic or
other suitable shape instead of being square as described.

page_text: We do not claim generally the construction of lifting or hoisting machinery in
which the load remains sustained when the power applied to raise or lower it is
withdrawn, but having now particularly described and ascertained the nature of
our said Invention and in what manner the same is to be performed, we declare
that what we claim is:-
In self sustaining lifts or hoists the combination of the shaft a, key or feather d,
ring or segments e, e, ring h, and bar g, arranged and operating substantially as and
for the purpose described and shewn in the drawings.
1001