AN IMPROVED SAFETY APPARATUS FOR LIFTS OR HOISTS AND OTHER LIKE MACHINERY
Year: 1874

page_text: LETTERS PATENT to Henry Albert Davis, of Appleby Road, Dalston,
in the County of Middlesex, for the Invention of "AN IMPROVED
SAFETY APPARATUS FOR LIFTS OR HOISTS AND OTHER LIKE MACHINERY.”
Sealed the 22nd January 1875, and dated the 24th November 1874.
PROVISIONAL SPECIFICATION left by the said Henry Albert Davis
at the Office of the Commissioners of Patents, with his Petition,
on the 24th November 1874.
I, HENRY ALBERT DAVIS, of Appleby Road, Dalston, in the County of
Middlesex, do hereby declare the nature of the said Invention for "AN
IMPROVED SAFETY APPARATUS FOR LIFTS OR HOISTS AND OTHER LIKE MACHINERY,"
to be as follows:-
==
My said Invention relates to simple apparatus to be applied to the cage,
box, chamber, or platform of a hoist or lift used in a hotel, warehouse,
or other building, or in mines or otherwise, for raising or lowering persons
or merchandize, and is designed to prevent the falling of the said cage
or box in case the rope or chain supporting the same should be broken
or detached.

page_text: In practising my said Invention I use a wedge or two or more wedges
suspended by separate or independent cords, ropes, or chains in such a
position between the said cage or box and the vertical guide posts or
standards between which the said cage or box ascends and descends,
that on the breaking or detachment of the said rope, cord, or chain the
said wedge or wedges will be caught between the said cage or box and
posts, and will bind or jam the cage or box, so that its fall or descent
will be impossible until it has been released from the said wedges. The
said wedge or wedges must be arranged with their thin edge upward,
and projecting between the cage or box and the guide posts, the thick
end being below the said cago or box. I prefer to form recesses in the
cage or box to receive the end of the wedges, and with grooves for their
ropes or chains. The said wedges should have flanges or pins to guide
them upon the said posts or standards. I may form a guide by con-
structing the wedge with a central tongue fitting and sliding in a central
groove or guide way formed in the vertical guide posts, but I prefer to
provide the said wedge with guide flanges or pins projecting over the
sides of the said post. In the event of the breaking of the cord, rope, or
chain whereby the cage or box is suspended the said cage or box, no
matter how heavily it may be loaded, cannot drop more than an almost
imperceptible distance before it is caught and jammed by the said wedge
or wedges, and therefore the persons or objects in the said cage will
suffer no injury, and no inconvenienco will arise beyond the short delay
required for repairing the said chain or rope, and releasing the cage or
box from the wedge or wedges.
To increase the efficiency of the said safety apparatus I form the lower
or thick end of the wedge with a sharp tooth or projection, which, when
the wedge is forced into contact with the post by the dropping of the
aforesaid cage or box from its suspending rope or chain, will be forced
into the said post; or for the same purpose I provide the wedge with
pointed pins or spurs, which are attached to a plate on one face of the
said wedge, and passed through holes therein. While the said cage or
box remains suspended by its rope or chain these pins or spurs are kept
back by a spring, but when the cage escapes from its rope the points of
the said pins will be forced into the post or standard, and will ensure thie
safe retention and support of the aforesaid cage or box.
The winding apparatus of the hoist or lift to which my Invention is
1
1
3.02.

page_text: such slight changes as may be required for the reception and working of
the cords or chains of the aforesaid wedges, and for keeping the said
wedges in the proper position with regard to the cage or box.
filed by the said Henry Albert Davis in the Great Seal Patent
Office on the 22nd May 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
ALBERT DAVIS, of Appleby Road, Dalston, in the County of Middlesex,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of November, in the year
of our Lord One thousand cight hundred and seventy-four, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Henry Albert Davis, Her
special licence that I, the said Henry Albert Davis, my executors,
administrators, and assigns, or such others as I, the said Henry Albert
Davis, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"AN IMPROVED SAFETY APPARATUS FOR LIFTS OR HOISTS AND OTHER LIKE
said
MACHINERY," upon the condition (amongst others) that I, the,
Henry Albert Davis, my executors or administrators, by an instrument
in writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters
Patent.

page_text: and by the following statement, reference being had to the accompanying
Drawing forming a part of this Specification: -
My said Invention relates to apparatus to be used in combination
with the cage, box, chamber, or platform, or ascending and descending
part of a hoist, or lift, or machine for raising or lowering persons or
merchandize used in hotels, warehouses, or other buildings, or in mines
or other places, and is designed to prevent the falling of the said
cago or box or ascending and descending part of the hoist or lift, in case
the rope or chain supporting the same should be broken or dis-
connected.
My improved safety apparatus is constructed as shown in the accom-
panying Drawing, in which,—
Figure 1 is a horizontal section of a portion of a lift provided with my
improved safety apparatus.
Figure 2 is a side clevation of a portion of a lift provided with the
said apparatus.
Figure 3 is a vertical section showing a modification of the said
apparatus.
Figures 4 and 5 are elevations illustrating further modifications of the
said apparatus.
Figure 6 is an elevation showing the adaptation of the said Invention
for use in coal mines.
Like letters indicate the same parts throughout the Drawing.
a, a, are the fixed vertical guide posts, between which the cage or
platform of the lift moves in ascending and descending; b is the cage,
box, or chamber, in which the persons or objects are raised or lowered;
b' is the rope or chain for supporting and operating the said cage, box,
or chamber; c, c, are the wedges of my safety apparatus; d, d, are cords
or chains supporting the same. I use one wedge or two or more of these
wedges suspended by these separate or independent cords, ropes, or
chains d, in such a position between the said cage or box band the
vertical guide posts or standards a, between which the said cage or box
ascends and descends, that on the breaking or detachment of the said
rope, cord, or chain b¹ the said wedge or wedges will be almost imme-
diately caught between the said cage or box and posts, and will bind or

page_text: jam the cage or box so that its further fall or descent will be impossible
until it has been released from the said wedges. The said wedge or
wedges c must be arranged with their thin edge upward, and projecting
between the cage or box and the guide posts, the thick end being below
the said cage or box, as clearly shown in Figure 2. I prefer to form
recesses b² in the cage or box to receive the thin end of the wedge,
and grooves ³ for the ropes or chains d. The said wedges should have
flanges c¹ or pins to guide them upon the posts or standards a.
I may
form a guide by constructing the wedge with a central tongue fitting
and sliding in a central groove or guide way made in the vertical guide
post, but I prefer to provide the said wedge with guide flanges c¹, as
shewn, projecting over the sides of the said post. In the event of the
breaking of the cord, rope, or chain b', whereby the cage or box is
suspended, thic said cage or box, no matter how heavily it may be loaded,
can only drop an almost imperceptible distance before it is caught and
jammed by the said wedge or wedges, and therefore neither the cage,
box, or chamber, or the persons or objects in the same, will suffer any
injury, and persons ascending or descending therein will be subject to no
inconvenience beyond the short delay required for repairing or re-con-
necting the said chain or rope, and releasing the cage or box from the
wedge or wedges c.
To increase the efficiency of the said safety apparatus I form the lower
or thick end of the wedge with sharp teeth or projections c², which when
the wedge is forced into contact with the post by the dropping of the
cage or box 6 from its suspending rope or chain &' will be forced into the
post a; or for the same purpose I construct the wedge, as shewn in
Figure 3, that is to say, I provide it with a pointed pin or spur e, or two
or more of the same attached to a plate fon one face of the said wedge,
and passed through a hole or holes therein. While the said cage or box
remains suspended by its rope or chain these pins or spurs e arc kept
back by a spring g, but when the cagc b escapes from its rope the point
of the said pins will be forced into the post or standard, and will more
fully ensure the quick catching and safe retention and support of the
aforesaid cage or box.
In the apparatus shown in Figures 4 and 5 the wedge is connected by
a cord / to the cage or box, and the flanges c¹ of the wedge are provided
with springs c³, which bind upon the sides of the guide posts a, thereby
retarding the descent of the wedges, so that if the chain or rope b' breaks

page_text: the cage or box in falling will overtake the wedges, and be stopped within
a very short distance.
In some instances I provide the cage or box with iron or brass plates i,
as shown in Figure 1, which embrace and slide upon the posts a, and
serve to guide the said cage or box in its ascent or descent; and to further
ensure the instantaneous arrest of the cage in case of accident these
plates act in combination with the wedges as clamps.
The winding apparatus of the hoist or lift to which my Invention is
applied may be the same as in other hoists or lifts, with the exception
of such slight changes as may be required for the arrangement of the
cords or chains of the aforesaid wedges, and for keeping the said wedges
in the proper position with regard to the cage or box.
For general purposes, as in warehouse and hotel lifts, I prefer to
extend the cords of the wedges over a pulley or wheel at the top of the
guide post, and connect them to the balance weight ordinarily used 1
as a counterpoise to the cage or box of the lift.
The said safety apparatus may also be used as a brake to stop the cage
or box in any position by bringing the wedge or wedges into close contact
with the cage or box by means of a cord manipulated by the attendant
or other person at the bottom or other portion of the building wherein 2
the lift is placed; and the box or cage of the lift in all cases should have
a hole in one of its sides to allow a person inside the same free access to
the cord of the wedge or wedges for the purpose of stopping the cage or
box in any required position.
In Figure 6 I have shown an arrangement of apparatus very con-
venient for coal mines. In this arrangement the rope b' is passed over
the pulley j, and extended to the engine. The wedges-are suspended by
a rope, which is passed over a pulley or wheel %, and provided with a
balance weight 7.
Having thus fully described my said Invention, and the manner of
performing the same, I wish it understood that I claim,-
First. In a hoist or lift or machine for raising and lowering heavy
bodies or objects the employment of a wedge or wedges suspended inde-
pendently of the supporting rope or chain of the cage, box, or platform,
or ascending and descending part of the said hoist or lift, and operating
as hercin set forth to prevent the falling of the said cage, box, or plat-
2

page_text: form when the same is released or detached from the said supporting
rope or chain.
Second. Constructing the wedge or wedges c with teeth c³, and with
flanges c' or other suitable guides, with or without springs, as herein set
forth and for the purposes specified.
Third. Constructing the wedge c with pins or teeth e fixed in a hinged
or jointed plate, and passing through holes in the body of the said
wedge, as herein set forth and for the purpose specified.
In witness whereof, I, the said Henry Albert Davis, have here.
unto set my hand and scal, this Twenty-second day of May, in
the year of our Lord One thousand eight hundred and seventy-
five.
HENRY ALBERT DAVIS. (L.S.)
Witness,
JA³. EDWARDS,
8, Southampton Buildings,
London.