IMPROVEMENTS IN SAFETY TACKLE FOR RAISING AND LOWERING HEAVY WEIGHTS
Year: 1868

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN SAFETY TACKLE FOR RAISING AND LOWERING HEAVY
WEIGHTS." A communication from abroad by Benjamin Bellair, of
Paris, in the Empire of France.
Sealed the 20th April 1869, and dated the 24th November 1868.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition,
on the 24th November 1868.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
5 of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN SAFETY TACKLE FOR RAISING AND LOWERING
HEAVY WEIGHTS," a communication from abroad by Benjamin Bellair,
of Paris, in the Empire of France, to be as follows:-
This Invention relates, firstly, to certain improvements in the safety
tackle for which Letters Patent were granted to Pierre Joseph Jamet,
bearing date the 3rd of April 1865, No. 937.

page_text: And, secondly. To certain new constructions and arrangements of
safety tackle.
According to the first part of this Invention it is proposed to introduce
into the oscillating pulley block described in the Specification of the
said Patent a hinged break which is acted upon by the fixed "cross
piece," and applys friction to the whole of the rope on the upper surface
of the "return pulley," in lieu of one part only of such rope being
nipped directly between the "cross piece" and the pulley itself, whereby
the rope was liable to become injured.
According to the second part of this Invention the oscillating motion
of the upper pulley block, as well as the "special "return pulley" itself,
are dispensed with, a ratchet wheel and detent hinged to a break being
substituted therefor. The ratchet wheel is mounted upon the axsis of
the sneaves, and into the teeth of this ratchet wheel engages the detent
which is hinged to the break. This break has a concave surface, and
presses upon a considerable length of that portion of the rope which
rests upon the upper surface of the sheave or sheaves. When the
weight is left to hang freely it tends to turn the ratchet wheel, which
in its turn acts upon the detent, and causes the break to which the
detent is hung to be applied to the rope passing over the pulley with a
force proportionate to the weight of the suspended load, and thereby
prevented it from running down. The detent is lifted clear of the
ratchet wheel, and the break taken off by means of a separate cord
attached to the tail of the detent lever, and passing over an overhead
guide; or in lieu of this separate cord for disengaging the detent in
case of a load requiring to be lowered, the same result may be effected
by the fall rope itself. For this purpose an oscillating frame is hung
freely on the axis of the sheaves in the upper block, the fall rope.
passing down through an eye in the bottom cross bar of this frame
whilst its upper cross bar can be brought to bear against the detent
lever, and thereby release it from the ratchet wheel by simply pulling
the fall rope laterally or out of the perpendicular.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 24th May 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, 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 eight hundred and sixty-eight, in the
32nd year of Her reign, did; for Herself, Her heirs and successors, give
and grant unto me, the said John Henry Johnson, Her special
license that I, the said John Henry Johnson, my executors, adminis-
trators, and assigns, or such others as I, the said John Henry
Jolinson, my executors, administrators, or 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 Inven-
tion for "IMPROVEMENTS IN SAFETY TACKLE FOR RAISING AND LOWERING HEAVY
WEIGHTS," a communication from abroad by Benjamin Bellair, of
Paris, in the Empire of France, upon the condition (amongst others)
that I, the said John Henry Johnson, my executors or administrators,
by an instrument in writing under my hand and seal, 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.
NOW KNOW YE, that I, the said John Henry Johnson, 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, reference being had to the accom-
panying Drawings, and to the letters and figures marked thereon, that
is to say:
The said Invention relates, firstly, to certain improvements in tho
safety tackle for which Letters Patent were granted to Pierre Joseph
Jamet, bearing date the Third day of April, One thousand eight hundred
and sixty-five, No. 937.

page_text: And, secondly. To certain new constructions and arrangements of
safety tackle.
According to the first part of this Invention it is proposed to introduce
into the oscillating pulley block described in the Specification of the
said Patent, a hinged break which is acted upon by the fixed "cross
piece," and applies friction to the whole of the rope on the upper surface
of the "return pulley" in lieu of one part only of such rope being
nipped directly between the "cross piece" and the pulley itself, whereby
the rope was liable to become injured.
According to the second part of this Invention the oscillating motion
of the upper pulley block, as well as the special return pulley itself,
are dispensed with, a ratchet wheel and detent hinged to a break being
substituted therefor. The ratchet wheel is mounted upon the axis of
the sheaves, and into the teeth of this ratchet wheel engages the detent
which is hinged to the break. This break has a concave surface and
presses upon a considerable length of that portion of the rope which
rests upon the upper surface of the sheave or sheaves.
When the
weight is left to hang freely it tends to turn the ratchet wheel, which in
its turn acts upon the detent, and causes the break to which the detent
is hung to be applied to the rope passing over the pulley with a force
proportionate to the weight of the suspended load, and thereby prevents
it from running down. The detent is lifted clear of the ratchet wheel,
and the break taken off by means of a separate cord attached to the
tail of the detent lever, and passing over an overhead guide; or in lieu
of this separate cord for disengaging the detent in case of a load
requiring to be lowered the same result may be effected by the fall rope
itself. For this purpose an oscillating frame is hung freely on the axis
of the sheaves in the upper block, the fall rope passing down through
an eye in the bottom cross bar of this frame, whilst its upper cross bar
can be brought to bear against the detent lever, and thereby release it
from the ratchet whcel by simply pulling the fall rope laterally or out
of the perpendicular,
And in order that the said Invention may be fully understood I shall
now proceed more particularly to describe the same, and for that purpose
shall refer to the several Figures on the annexed Sheet of Drawings, the
same letters of reference indicating corresponding parts in all the
corresponding Figures.
In the improved arrangement of safety tackle shown at Figure 1 of

page_text: the annexed Sheet of Drawings the pressure of the piece K is not
exerted directly upon the fall rope g, as was previously the case, but
upon the intermediate piece or break i, which embraces a large surface
of the fall or haulling rope g, and works at one end on the centre K'.
On releasing the fall the weight of the load causes the upper block to
oscillate or turn partly on its centre, and the piece K brings its pressure
to bear upon the break i, which nips the fall rope not at one point only
but over the entire portion resting upon the return pully, whereby
the wear and tear of the rope is considerably reduced.
Should
Figures 2 and 3 represent respectively a side and front view of a novel
arrangement of safety tackle. As will be seen on referring to the
Drawings there is mounted upon the axis of the sheaves a, a, a, a
ratchet wheel d which is enclosed by the check plate m. In the teeth
of this wheel engages a projection or detent n of the piece o jointed at p
to the break g which works on the centre r. If the attendant pulls at
the falls in the direction of the arrow 1 the ratchet wheel is free to
revolve, the detent n of the piece o allowing the teeth to pass freely,
but on the release of the fall the load produces a strain in the direction
of the arrow 2. This has the effect of engaging the detent n with one
of the teeth of the ratchet wheel and of applying the break powerfully.
The load will consequently be held suspended, and the attendant has
only to pull the fall again in the direction of the arrow 1 in order to
further lift the load. Each time the fall is let go the weight will be
prevented from running down by the application of the break.
it be required to allow the weight to descend freely the attendant pulls
a cord or rope which is attached at o' to the piece o, and passes up
through the guide 7. The strain upon this cord has the effect of raising
the piece o, and of thereby disengaging the detent n from the ratchet
wheel d, whereupon no obstacle will be presented to the free descent of
the weight or load. It is simply requisite to let go the cord in order to
stop the discent, as the piece o and break q will by their own gravity
return to their normal position again already described. If found
desirable the fall rope itself may be employed for disengaging the
detent n from the ratchet wheel and permitting the free descent of the
load. For this purpose the arrangement shewn at Figure 4 may be
used. It consists in passing the fall through the hole u in the piece o
fixed on the axis of the pulleys, and shewn detached at Figure 5. In
pulling the fall perpendicularly the piece is caused to turn slightly on

page_text: its axis, and the brass bar z then acts upon the piece o so as to dis-
engage the detent n, and by continuing its action presses upon the
projection w of the break, which it elevates in its turn, thereby liberating
the load and allowing it to descend freely.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe in conclusion that what I con-
sider to be novel and original and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,-
First. The application and use to and in what is known as safety
tackle of a break which exerts pressure upon the whole or the greater
portion of that part of the fall or haulling rope which lies upon the
surface of the return pulley arranged and operated substantially as and
for the purpose herein-before described and illustrated by Figure 1 of the
Drawings annexed.
Second. The combination in what is known as self-acting safety
tackle of a ratchet wheel detent and break arranged and operating
substantially as and for the purpose herein-before described and illus-
trated by Figures 2 and 3 of the Drawings annexed.
Third. The peculiar construction of what is known as safety tackle, as
herein-before described and illustrated by Figure 4 of the Drawings
annexed, wherein the whole of the parts are operated by the fall or
haulling rope alone.
In witness whereof, I, the said John Henry Johnson, have to
this Specification set my hand and seal, the Twenty-fourth day
of May, One thousand eight hundred and sixty-nine.
J. HENRY JOHNSON. (L.S.)