A NEW OR IMPROVED AUTOMATIC PULLEY BLOCK BRAKE
Year: 1879

page_text: LETTERS PATENT to Charles Albert Tow, of Birmingham, in the County of
Warwick, Engineer, for the Invention of "A NEW OR IMPROVED AUTOMATIC
PULLEY BLOCK BRAKE."
PROVISIONAL SPECIFICATION left by the said Charles Albert Tew at the
Office of the Commissioners of Patents on the 12th December 1879.
CHARLES ALBERT TEW, of Birmingham, in the County of Warwick, Engineer.
"A NEW OR IMPROVED AUTOMATIC PULLEY BLOCK BRAKE,"
My improved break or "brake" is by preference attached to the lower block of
the two forming a pair of pulley blocks, and may be applied to ordinary blocks
having one or more sheaves or pulleys.
For the purposes of my Invention I provide a short rod which is to act as a lever,
and which is of suitable length, and being drilled through its centre horizontally so
that it will partly turn upon the top or uppermost crossbar of a pulley block. An
opening or aperture is made in cach end of this sufficiently large for the rope, cord,
or chain employed.
Two studs are inserted into this rod, one of which is made to rest upon the outer
plate of the block, so that when the weight is being lifted the bar is retained in a
horizontal position, the other stud being intended for a catch to take over it and
so to prevent the rod or lever from moving until it is allowed to do so.
The action of my improved break will then be as follows:-So long as the rod or
lever is maintained in a horizontal position the cord, chain, or rope will pass freely
through the block; but so soon as the catch is released during the action of
lowering the weight the rod or lever is drawn down by the friction of the rope or
chain against the sheave or pulley, and the rope is thereby securely locked.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Albert Tew in the Great Seal Patent Office on the 11th
June 1880.
CHARLES ALBERT TEW, of Birmingham, in the County of Warwick, Engineer.
"A NEW OR IMPROVED AUTOMATIC PULLEY BLOCK BRAKE."
My improved break or "brake" is by preference attached to the lower block of
the two forming a pair of pulley blocks, and may be applied to ordinary blocks
having one or more sheaves or pulleys.
For the purposes of my Invention I provido a short rod which is to act as a lever,
and which is of suitable length, and having a hole drilled or cast through its centre
horizontally, so that it will partly turn upon the top or uppermost cross bar of a
pulley block, or on a separately arranged fulcrum fitted theroto.
An opening or aperture is made in each end of this bar in a direction contrary to
the fulcrum sufficiently large for the rope, cord or chain employed to pass through, or
as a modification of my Invention instead of holes being cast or drilled in the ends 1
of the bar it may be constructed with a hook at each end, or the bar may be
constructed of two plates rivetted together.
The bar or lever is so constructed that when in a horizontal position it rests on
the outer plate of the block, so that when the weight is being lifted the bar is
retained in a horizontal position, a stud is inserted in the bar and is intended for a 2
catch to take over it so as to prevent the rod or lever from moving until it is
allowed to do so.
The action of my improved break will then be as follows:-So long as the rod or
lever is maintained in a horizontal position the cord, chain, or rope will pass freely
through the ends of the lever and the block can be used as those of ordinary 2
construction, but so soon as the catch is released and the weight begins to fall the
rod or lever is drawn down by the friction of the rope or chain against the sheave
or pulley, and the rope is thereby securely locked and the weight suspended.
That my Invention may be fully understood I have annexed Drawings thereof,
which I now proceed to describe.
Fig. 1 is an elevation of a pulley block shewing the bar in a horizontal position
when the break is not in use.
Fig. 2 shews an end elevation.
Fig. 3 is an elevation of a pulley block shewing the bar in action.
Fig. 4 is an elevation shewing a modified arrangement of the catch.
Fig. 5 is a plan of the bar or lever.
Similar letters of reference are employed to indicato like parts in the several
Figures.
A is the bar or lever which is shown in elevation in Figures 1, 3, & 4, and of
which an end view is given in Fig. 2, and a plan view in Fig. 5. B, B, in Fig. 5 4
are the holes through which the rope C passes. C is the rope; D is the fulcrum
pin on which the bar or lever is pivoted.
E is the projecting piece which rests on the outer plate of the block when the
lever is in a horizontal position.
F is the catch which is pivoted on the pin G. In Figs. 1 and 3 this catch is 4
pivoted at its end, but Fig. 4 shews another arrangement in which the catch is
prolonged below the pivoting point G, and which projecting part is made to work
against a spring H whereby the catch is prevented from accidentally moving out of
its place.
In Fig. 4, H_is a spring against which the catch F is made to move, and J is a 5
handle for moving the catch in or out of gear as may be required.
Having now described the nature of my Invention and the manner in which the
same is or may be carried into effect, I desire it to be understood that what I claim

page_text: as the Invention to be protected by the hereinbefore in part recited Letters Patent
is, the construction of a new or improved pulley block brake, substantially as
hereinbefore described, and as illustrated in the accompanying Drawings, in which
the bar or lever (which may be made in one or more pieces) is constructed with
vertical holes in its ends for the rope to pass through, and which bar is pivoted on
the cross bar of either one of a pair of blocks.
I claim also as part of my Invention the same bar fixed in any other convenient
position for producing a like effect; and also the same bar constructed with a
hook or other similar contrivance at each end and intended for the same purpose.
I claim also,--
The catch which is employed to retain the said bar in a horizontal position, so that
blocks made with the said bar can be used as ordinary ones. It will be understood
that the said catch may be made to work either with or without a spring.
In witness whereof, I, the said Charles Albert Tew, have hereunto set my
hand and seal, this Eighth day of June, in the year of our Lord One
thousand eight hundred and eighty.