IMPROVEMENTS IN HOISTING AND LIFTING APPARATUS
Year: 1878

page_text: LETTERS PATENT to Henry Harris Lake, of the Office of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention of
"IMPROVEMENTS IN HOISTING AND LIFTING APPARATUS." A communication
from abroad by Charles Stokes, of Chicago, Illinois, United States of America.
ealed the 20th June 1879, and dated the 30th December 187
PROVISIONAL SPECIFICATION left by the said Henry Harris Lake at
the Office of the Commissioners of Patents on the 30th December 1878.
HENRY HARRIS LAKE, of the Office of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN HOISTING OR LIFTING
APPARATUS." [A communication from abroad by Charles Stokes, of Chicago,
Illinois, United States of America, Merchant.]
This Invention relates to improvements in hoisting or lifting apparatus or
machinery and is designed to provide improved safety lock apparatus whereby if
the hoisting rope should break the elevator would be securely locked to the elevator-
guides. The said improvements comprise the employment of slotted dogs pivotted
to the head of the draw-bar and combined with guides to direct the dogs into
notched racks, and with a spring and adjustable jamb-nut, whereby the dogs may
be adjusted to notched racks after they may have become worn, or to racks standing
a greater or less distance from the elevator proper. The advantage of this combi-
nation is that the elevator is supported wholly on the adjustable nut which controls
the position of the dogs in relation to the racks, and that there is no greater force
on a coiled spring, hereinafter mentioned, when raising one weight than another.
This device differs from the elliptic spring which straightens out to catch in the
notches of the racks, in that the pitch of the dogs is not such as to cause them to
press with too great force against the guides, but there is sufficient pitch to enable
the dogs to hold the platform suspended although the guides should to any ordinary
amount spread.
In carrying the said Invention into practice I provide a frame which is a con-
tinuous piece of iron extending from the lifting beam of a hoisting apparatus far
.

page_text: enough up to permit a coiled spring to be placed within its walls, and also properly
to guide a draft bar and support it in a vertical position, a hole being made through
the top of the frame for said bar to pass. The lower part of the said frame is pro-
vided with flanges which, by means of connecting rods or bolts, are fastened to a
strong iron plate which is placed flatwise under the lifting beam and projects
laterally over the sides to permit the said bolts to pass through it. The bolts fitting
closely to the lifting beam prevent the frame or plate from turning out of place.
The aforesaid draft-bar passes through the said lifting beam and also through the
said iron plate, and on the lower end of the bar is formed a screw-thread on which
a jamb-nut is placed to sustain the weight of the elevator or platform. Above the
lifting beam is placed a nut, between which and the top of the frame is placed the
aforesaid coiled spring, of such strength as will ensure the instantaneous movement
of the dogs outward, should the hoisting rope break. A socket-head is formed on
the upper end of the said draft-bar, and to it are pivoted dogs, the ends of which
have bearings against said head, so that the pivots are not wholly relied on as
supports against the pressure of the dogs endwise, as when engaging the racks.
The middle portion of these dogs are provided with slots through which pins from
the guide pass, and not only act as fulcrums for the dogs to turn on to some extent,
but permit the dogs to have a longitudinal movement, both of said movements being
necessary to enable the dogs to enter the notches in the aforesaid racks in case the
cord or rope should break. The outer guides not only direct the dogs at all times
into these racks but they prevent the dogs from springing or being bent up by any
sudden jar they may be liable to. The device is automatic in its operation as con-
structed, the only attention required is to turn up the nut so as to keep the outer
ends of the dogs as close to the racks as possible but not so as to enter the notches
in the movement of the elevator or platform. The object of that position of the
dogs in relation to the rack is that the dogs shall move the shortest possible
distance to catch in the notches of the rack in case the rope should break. "

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Harris Lake in the Great Seal Patent Office on the 28th June
1879.
HENRY HARRIS LAKE, of the Office of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN HOISTING OR LIFTING
APPARATUS." A communication from abroad by Charles Stokes, of Chicago, Illinois,
United States of America, Merchant.
This Invention relates to improvements in hoisting or lifting apparatus or
machinery, and is designed to provide improved safety apparatus whereby if the
hoisting rope should break the elevator would be securely locked to the elevator
guides. The said improvements comprise the employment of slotted dogs pivotted
to the head of the draw-bar and combined with guides to direct the dogs into
notched racks, and with a spring and adjustable jamb-nut, whereby the dogs may
be adjusted to the notched racks after they may have become worn, or to racks
standing a greater or less distance from the elevator or platform. The advantages
of this combination are that the elevator is supported wholly on the adjustable nut
which controls the position of the dogs in relation to the racks, and that there is no
greater force on a coiled spring herein-after mentioned when raising one weight than
when raising another. This device differs from the elliptic spring which straightens
out to engage with the notches of the racks, in that the pitch of the dogs is not
such as to cause them to press with too great force against the guides, but there is
sufficient pitch to enable the said dogs to hold the platform suspended although the
guides should spread to any ordinary extent.
Figure 1 is an elevation of a hoisting machine embodying these improvements.
Figure 2 is a plan or top view of the locking devices and elevator-beam
detached.
Figure 3 shews one of the slotted dogs removed from its guides and its connection
with the head of the draw-bar.
Figure 4 shews the guides to one dog taken transversely to the dog which operates
therein.
Figure 5 is a perspective view of the frame which supports and guides the
draw-bar and also supports the upper end of the spring which forces the dogs out-
ward and into the notches of the rack.
Figures 2, 3, 4, 5 are drawn to an enlarged scale.
A represents the lifting beam of an ordinary hoisting machine or elevator, and
B, B, are the elevator-guides; C, C, are the toothed or notched racks in which the
locking devices of the elevator are to catch in case the hoisting rope should break.
All of the above parts are of the ordinary construction; D represents a frame which
is a continuous piece of iron extending up from the beam A far enough to permit a
coiled spring E to be placed within its walls, and also to properly guide the draft-
bar F and support it in a vertical position, a hole being made through the top of the
frame for the said bar to pass. The lower part of the frame D is provided with flanges
G, G, which by means of connecting rods or bolts H, H, are fastened to a strong
iron plate I, which is placed flatwise under the lifting beam A and projects latterally
over the sides to permit the bolts H to pass through it. The bolts fitting closely to
the beam A prevent the frame or plate from turning out of place. The draft-bar F
passes through the lifting beam A and also through the plate I, and on the lower
end of the bar is formed a screw-thread on which a jamb-nut J is placed to sustain
the weight of the elevator or platform. Above the beam A is placed a nut K,
between which and the top of frame is arranged the coiled spring E, of such strength
as will ensure the instantaneous movement of the dogs outward should the hoisting

page_text: rope I break.
A socket-head M is formed on the upper end of the draft-bar F, and
to it are pivoted at P dogs N, N, the ends of which have bearings against said head
so that the pivots are not relied on as the sole supports against the pressure of the
dogs endwise, as when engaging the racks. The middle portions of these dogs are
provided with slots R, through which pins b from the guides S, S pass;
these pins not only act as fulcrums for the dogs to turn on to some extent, but
permit the dogs to have a longitudinal movement, both of these said movements being
necessary to enable the dogs to enter the notches in the racks C, C, in case the cord
or rope L should break. The outer guides T, T, not only direct the dogs at all
times into these racks C, C, but also prevent the dogs from springing or being
bent up by any sudden jar they may be liable to. The device is automatic in its
operation, the only attention required being to turn up the nut J so as to keep the
outer ends of the dogs N, N, as close to the racks C as possible, but not so as to
enter the notches in the movement of the elevator or platform. The object of
causing the dogs to occupy this position in relation to the rack is that the dogs
shall move the shortest possible distance to catch in the notches of the rack in case
the rope L should break.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it under-
stood that I claim,-
The slotted dogs having fulcrums and being capable of sliding on pins b, in com-
bination h the guides, the draft-bar and head, the spring, the frame, the plate,
the lifting beam, and the set-nut and jamb-nut, as and for the purpose set forth.
In witness whereof, I, the said Henry Harris Lake, have hereunto set
my hand and seal, this Twenty eighth day of June, in the year of our Lord
One thousand eight hundred and seventy nine.