IMPROVED SAFETY APPARATUS FOR HOISTS, LIFTS, CRANES, AND OTHER SIMILAR MACHINERY
Year: 1873

page_text: LETTERS PATENT to Henry Thomas Davis, of St. Donatt's Road,
Lewisham Road, New Oross, in the County of Surrey, for the
Invention of "IMPROVED SAFETY APPARATUS FOR HOISTS, LIFTS, CRANES,
AND OTHER SIMILAR MACHINERY."
Sealed the 2nd April 1874, and dated the 9th October 1873.
PROVISIONAL SPECIFICATION left by the said Henry Thomas Davis
at the Office of the Commissioners of Patents, with his Petition, on
the 9th October 1873.
I, HENRY THOMAS DAVIS, of St. Donatt's Road, Lewisham Road,
New Cross, in the County of Surrey, do hereby declare the nature of the
said Invention for "IMPROVED SAFETY APPARATUS FOR HOISTS, LIFTS, CRANES,
AND OTHER SIMILAR MACHINERY,” to be as follows:-
My Invention relates to apparatus for proventing accidents by tho
breaking of the rope or chain whereby the weight is suspended in a
hoist or other machine for raising or elevating heavy bodies or objects.
It is chiefly designed for application to the hoists or lifts employed in
hotels, warehouses, hospitals, and other lofty buildings, where the

page_text: persons or objects to be raised or lowered are placed in a cage or
chamber suspended by a rope or chain from the top of the building, and
where the falling of the said cage or chamber would probably be attended
with loss of life and other serious consequences.
My improved apparatus is constructed as follows:-A frame of wrought
iron or other suitable metal is securely attached to the top of the sus-
pended cage, box, or chamber of the machine. This frame consists of
two sides united by a strong cross bar extending across the top of the
cage. This cross bar has at its centre a hole, through which is passed a
short rod attached to the rope or chain whereby the said cage is sus-
pended. The said rod is attached to a block or link of wrought iron or
other suitable metal, to which I joint two bars or spurs, whose outer
ends project through slots or holes in vertical flat bars, which are secured
to the sides of the aforesaid frame. When these spurs or bars are held
up by the rope their outer ends are drawn in nearly flush with the side
frames, but when the inner ends of the said bars are released and allowed
to fall they are thrown outward. The cage is placed between vertical
guide posts, between which it is raised and lowered. I form in the inner
sides of these guide posts channels or grooves for the reception of the
vertical flat bars secured on the side frames of the cage. If the said guide
posts are formed of wood I prefer that the back and sides of the channels
should be lined with iron or other suitable metal. In the back of the
said grooves or channels I form at suitable intervals slots or holes of
suitable size to admit freely the ends of the aforesaid spurs or bolts,
which ends project through the aforesaid flat bars of the side frames into
the channels or grooves in the guide posts.
"
As the inner ends of the said spurs are jointed to the central block to
which the suspended rope of the cage is secured it is obvious that so
long as the said rope remains intact the spurs will not project far enough
through the side frames to arrest or impede the movement of the cage
between its guides; but if the rope should break the inner ends of the
said spurs immediately drop, the outer ends are pressed outward, and
before the cage can fall more than a very slight distance they enter the
aforesaid slots and act as bolts, whereby the cage is immediately stopped
in its descent, and held in safety until the rope is repaired.
the
•
I prefer to attach a weight to the aforesaid short rod which connects
rope to the said spurs to accelerate the action of the latter when the

page_text: said rope breaks. The slots in the guide bars should have their upper
edges curved or sloped to facilitate the entrance of the spurs or bolts,
while the lower edge must be left square to form a solid support for the
said spurs or bolts. I prefer to provide the top of the cage with spring
latches, which catch and firmly hold the said spurs when they have
fallen.
I sometimes modify the above described apparatus as follows, namely,
I make the vertical side bars on the cage capable of adjustment, and
'combine with them at their lower ends spring bolts, which are held back
by the said bars till the rope breaks; and are then released and enter
the slots in the guide posts, thereby forming an additional support for
the cage.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Thomas Davis in the Great Seal Patent
Office on the 9th April 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
THOMAS DAVIS, of St. Donatt's Road, Lewisham Road, New Cross, in
the County of Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of October, in the year
of our Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Henry Thomas Davis, Her special licence
that I, the said Henry Thomas Davis, my executors, administrators,
and assigns, or such others as I, the said Henry Thomas Davis, my
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter 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
"IMPROVED SAFETY APPARATUS FOR HOISTS, LIFTS, CRANES, AND OTHER SIMILAR
MACHINERY," upon the condition (amongst others) that I, the said Henry
Thomas Davis, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should particu-
larly describe and ascertain the nature of the said Invention, and in whạt

page_text: 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.
NOW KNOW YE, that I, the said Henry Thomas Davis, do hereby
declare the nature of my said Invention, 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 apparatus for preventing accidents by the
breaking of the rope or chain whereby the weight is suspended in a
hoist or other machine for raising or elevating heavy bodies or objects.
It is chiefly designed for application to the hoists or lifts employed in
hotels, warehouses, hospitals, and other lofty buildings, where the
persons or objects to be raised or lowered are placed in a cage or chamber
suspended by a rope or chain from the top of the building, and where
the falling of the said cage or chamber would probably be attended with
loss of life and other serious consequences.
My improved apparatus is constructed as follows:-A frame of wrought
iron or other suitable metal is securely attached to the top of the sus-
pended box or chamber of the machine. This frame consists of two
sides united by a strong cross bar extending across the top of the cage.
This cross bar has at its centre a hole, through which is passed a short
rod attached to the rope or chain whereby the said cage is suspended.
.The said rod is attached to a block or link of wrought iron or other
suitable metal, to which I joint two bars or spurs, whose outer ends
project through slots or holes in the side frames and in vertical flat
guiding bars, which are secured to the sides of the aforesaid frame.
When these spurs or bars are held up by the rope their outer ends are
drawn in nearly flush with the side frames or vertical flat guiding bars,
but when the inner ends of the said spurs or bars are released and allowed
to fall they are thrown outward. The cage is placed between vertical
guide posts, between which it is raised and lowered, and on the inner
sides of these guide posts I form channels or grooves for the reception of
the vertical flat guiding bars, these being secured to but shifting or
sliding on or against the side frames of the cage. If the said guide
posts are formed of wood I prefer that the back and sides of the channels
should be lined with iron or other suitable metal. In the back of the
said grooves or channels I form at suitable intervals slots or holcs of
•

page_text: suitable size to admit freely the ends of the aforesaid spurs or bolts,
which ends project through the aforesaid flat bars of the side frames into
the channels or grooves in the guide posts.
As the inner ends of the said spurs are jointed to the central block, to
which the suspending rope of the cage is secured, it is obvious that so
long as the said rope supports the weight of the cage the spurs will not
project far enough through the side frames and vertical guide bars to
arrest or impede the movement of the cage between its guides, but if the
rope should break, and consequently cease to support the weight of the
cage, the inner ends of the said spurs will immediately drop, and their
outer ends be pressed outward, and before the cage can fall more than a
very slight distance these ends will enter the aforesaid slots and act as
bolts, whereby the cage will be immediately stopped in its descent and
held in safety whilst the rope is being repaired.
I prefer to attach a weight or spring or both to the aforesaid short rod,
which connects the rope to the said spurs, to accelerate the action of the
latter when the said rope breaks, and firmly hold down the spurs when
they have fallen.
The vertical flat guiding bars are capable of adjustment by sliding
vertically, so as to hold back or release spring bolts on the under side of
the cage, the bolts being held back by the said guiding bars till the rope
breaks, when they become released and enter or shoot into the slots or
holes in the guide posts, thereby forming an additional support for the
cage.
The accompanying Drawing illustrates the construction of the improved
apparatus.
Figure 1 is perspective view; Figure 2, vertical section; Figure 3,
side elevation of inner face of one of the vertical guide posts; and
Figure 4, plan view of under side of the cage, shewing spring bolts and
horizontal section of guide posts.
a is the cage; b, the wrought-iron frame; and c, the cross bar, by
which the cage is suspended by the rod d and rope e; f, is the block or
link; and g, g, the two stopping bars or spurs; h, h, the vertical flat
guiding bars; i, i, the vertical guide posts; k, k, iron linings to same,
providing for the outer ends of the stopping bars or spurs, either slots or
holes, as above described, or preferably rackwork, as shown in the

page_text: כי
1
Drawing; is the weight; and 7*, the spring for better ensuring the
action of the bars g, g. The vertical flat bars h have in them at intervals
slots to admit of their sliding on pins h* protuding from the sides of
the cage. The Figure 4 shew the spring bolts m, m, held back from
action by the vertical bars ; and Figure 2 shews them released and
engaged in the rackwork. The release of the bolts m is thus effected:-
When the spurs or bars 9, 9, fall, their outer ends as they extend into
and engage with the rackwork, also by the act of falling, prize up or lift
the vertical flat guiding bars, and the feet or lower ends of these thus
become lifted out of the way of and no longer detain the bolts m, m,
from acting. These then consequently engage in the rackwork, and
form the additional support for the cage, as above mentioned. The
vertical distance between the spurs or bars 9, 9, in their down position,
and the bolts m, m, should be such as to correspond with the slots, holes,
or rackwork in the guide posts.
Having now described the nature of the said Invention, and the
'manner in which the same is to be and may be performed, I declare that
I claim as of the said Invention, the use in combination of stopping
bars at the top and of spring bolts at the bottom of the cage or chamber,
both held out of action while the cage or chamber is suspended, but
coming into action in the event of the rope or chain breaking, all
substantially as herein set forth and as represented in the Drawing.
In witness whereof, I, the said Henry Thomas Davis, have here-
unto set my hand and seal, this Ninth day of April, in the year
of our Lord One thousand eight hundred and seventy-four.