IMPROVEMENTS IN SNATCH BLOCKS
Year: 1871

page_text: LETTERS PATENT to George Tangye, of Birmingham, in the County
of Warwick, Engineer, for the Invention of "IMPROVEMENTS IN
SNATCH BLOCKS."
Sealed the 25th July 1871, and dated the 31st May 1871.
PROVISIONAL SPECIFICATION left by the said George Tangye at the
Office of the Commissioners of Patents, with his Petition, on the
31st May 1871.
I, GEORGE TANGYE, of Birmingham, in the County of Warwick,
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN SNATCH BLOCKS," to be as follows:-
This Invention consists of an improved construction or arrangement
of snatch block whereby the action of the weight or load automatically
locks the moveable strap or plate, rendering unnecessary the split pins
or fastenings commonly employed, and whereby also the rope or chain
may be more readily introduced or withdrawn than in those heretofore
made.

page_text: In carrying out my Invention I connect the moveable strap to the
cross head so that they swivel together on the pin of the cross head
The free
which secures it to the strap on the other side of the block.
end of the moveable strap is formed with a hook, slot, or groove, which,
when the weight is on the block, engages with a pin or projection,
preferably the pin on which the sheave of the block revolves. By
causing the moveable strap and cross head to swivel a space is left
above the sheave, through which the rope or chain may be introduced
or withdrawn. The hook being attached to the cross head in the usual
way by a neck and rivet the action of the weight causes the cross head
and moveable strap to swivel and lock the latter securely on the pin or
projection, as above described.
To render this locking more certain the moveable strap is so attached
to the cross head that when locked the centre line of the hook makes an
angle with the longitudinal centre line of the pulley block in side
elevation. The action of the weight tends to make these lines coincide
and the moveable strap engage with the pin or projection.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Tangye in the Great Seal Patent Office
on the 30th November 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
TANGYE, of Birmingham, in the County of Warwick, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirty-first day of May, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said George Tangye, Her special license that I,
the said George Tangye, my executors, administrators, and assigns, or
such others as I, the said George Tangye, 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 Invention for "IMPROVEMENTS IN SNATCH BLOCKS,"

page_text: upon the condition (amongst others) that I, the said George Tangye,
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 George Tangye, 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 accompanying
Drawings and to the letters and figures marked thereon (that is to
say):
:
My said Invention consists of an improved construction or arrange-
ment of snatch block whereby the action of the weight or load
automatically locks the moveable strap or plate, rendering unnecessary
the split pins or fastenings commonly employed, and whereby also the
rope or chain may be more readily introduced or withdrawn than in
those heretofore made.
And in order that my 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
Figures.
Figure 1 of my Drawings represents an edge view of my improved
snatch block; Figure 2 is a corresponding side elevation of the same,
shewing its position when a load is suspended therefrom; and Figure 3
is a similar view of the snatch block when opened for the adjustment
of the rope or chain thereon.
According to my Invention I connect the moveable strap A of the
snatch block to the cross head B in such a manner that they will swivel
together on the pin C of the cross head which secures it to the strap D
on the other side of the block. The free end of the moveable strap A
is formed with a hook, slot, or groove at a, which when the weight is
on the block engages with a pin or projection, preferably the pin E, on
which the sheave F of the block revolves. By causing the moveable
strap A and cross head B to swivel a space is left above the sheave, as
shown in Figure 3, through which the rope or chain may be introduced

page_text: or withdrawn. The hook G being attached to the cross head in the
usual way by a neck and rivet the action of the weight causes the cross
head and moveable strap to swivel and lock the latter securely on the
pin or projection E, as above described.
In order to render this locking more certain the moveable strap A is
so attached to the cross head B that when locked the centre line 1-2 of
the hook makes an angle with the longitudinal centre line 3-4 of the
The
pulley block in side elevation, as shewn clearly in Figure 2.
action of the weight consequently tends to make these lines coincide
and the moveable strap engage with the pin or projection E.
Having now described and particularly ascertained the nature of my
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
consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is, the
construction and use of snatch blocks wherein the action of the weight
or load automatically locks the moveable strap or plate, substantially
as and for the purpose herein-before described and illustrated by my
Drawings.
In witness whereof, I, the said George Tangye, have to this my
Specification set my hand and seal, this Twenty-fifth day of
November One thousand eight hundred and seventy-one.
Witness,
SAMUEL PUPLETT,
Engineer.
GEORGE TANGYE. (L.S.)