FORMING A DOUBLE CHAIN GUIDE FOR DIFFERENTIAL AND OTHER PULLEY BLOCKS
Year: 1884

page_text: PROVISIONAL SPECIFICATION,
We JOHN BARNSLEY ROBERT BARNSLEY, ALFRED BARNSLEY, JOHN WALTER
BARNSLEY and EARNEST FREDERICK HANDEL BARNSLEY all of Netherton in tho
County of Worcester Iron Founders and Pulley Block Manufacturers do heroby
declare the nature of our Invention for FORMING A DOUBLE CHAIN GUIDE FOR
DIFFERENTIAL AND OTHER PULLEY BLOCKS to be as follows:-
The Invention may be applied to all pulley blocks and pullies but particularly to
those known as Westons Differential Pulley Blocks.
The object of our Invention is to prevent any part of the chain used in working
the pulley blocks (whether the outer or the inner loops of the chain) from being
displaced from the teeth and grooves of the differential pulley and also to ensure
the fitting or engagement of every part of the chain (both the outer and the inner
loops) with the teeth and grooves of the pulley.
This is effected by means of the following combinations and additions to the
pulley block.
The two arms of the frame on either side of the differential pulloy are extended
and united each in the shape of two small curves, with the corresponding arms on
the other side of the frame. Through each of the extended corresponding arms or
curves is placed an axis parallel to the axis of the differential pulley and upon each
of the two additional axis two small wheels or rollers revolve. These wheels or
rollers are so curved and grooved and so placed that each one just misses the teeth
of the differential pulley and as they allow only sufficient space for the chain when
engaging the teeth and groove of the differential pulley to pass they thereby press
and force the chain into its proper place.
The four wheels or rollers are made to freely turn on their axis and when fixed
in their respective places each wheel or roller forms in conjunction with the teeth
and grooves of the differential pulley a passage of the shape and proportions of the
chain thereby ensuring that the chain as it passes on the differential pulley block
must fit and engage the teeth and grooves of such differential pulley.
Each wheel or roller effects its purpose independent of the other or others and
neither wheel or roller directly assists the other or others in placing the chain to

page_text: fit and engage the teeth and groove of such differential pulley but cach wheel or
roller attains this object with the assistance of the differential pulley itself.
Whichever way the chain is pulled whether to wind up or let down the block
carrying the weight there is always a wheel or roller working in conjunction with
the differential pulley to fit and engage the outer loop of the chain, as it passes on 5
to the pulley, with the teeth and groove of the differential pulley, and another one
to fit and engage the inner loop of the chain as it passes on to the pulley with the
teeth and groove of the differential pulley.

page_text: We JOHN BARNSLEY, ROBERT BARNSLEY ALFRED BARNSLEY JOHN WALTER
BARNSLEY and FARNEST FREDERICK HANDEL BARNSLEY all of Netherton in the
Parish of Dudley in the County of Worcester Ironfounders and Pulley Block
Manufacturers do hereby declare the nature of our Invention for IMPROVEMENTS
FOR FORMING A DOUBLE CHAIN GUIDE FOR DIFFERENTIAL AND OTHER PULLEY
BLOCKS and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
Our Invention may be applied to pulley blocks and pullies in general but more
especially to those pulley blocks known as Westons Differential Pulley Blocks.
The object of our Invention is to prevent the chain used in working the
differential pulley (whether the outer or the inner loops) being displaced from tho
teeth and grooves of the differential pulley and also to ensure the fitting and
engagement of every part of the chain (both the outer and the inner loops) with
the teeth and grooves of the pulley.
This is effected by the combination with the pulley block of four small wheels or
rollers with a groove in the middle of each wheel or roller and a curve on either
side of the groove.
The two arms on either side of the frame of the differential pulley are extended
or lowered and united each in the shape of two curves with the corresponding arms
on the other side of the frame. Through each of these extended corresponding
arms or curves is placed an axis parallel to the axis of the differential pulley and
upon each of the two additional axis are placed two small wheels or rollers which
revolve upon such axis. These wheels or rollers have a groove in the middle with
a curve on either side of the groove the joining of the groove with the curve on
either side of it forming a projecting edgo.
The wheels or rollers are made to turn freely on their axis and they are so
grooved curved and edged and so placed that each wheel or roller when revolving
forms in conjunction with the teeth and groove of the differential pulley as passage
of the proportions of the chain. As this passage is only sufficient to allow the
chain to pass when it is lying in such teeth and groove of the differential pulley it
consequently ensures that the chain as it passes on to the differential pulley must
fit in and engage the teeth and grooves thereof.
Each wheel or roller is placed apart from and effects its purpose independently
of the other or others and neither wheel or roller directly assists the other or others
in placing or forcing the chain to fit and engage the teeth and groove of the
differential pulley but each wheel or roller attains this object with the assistance of
the differential pulley itself.
The following will describe our Invention with reference to the Drawings
accompanying this Specification. Figure 1. represents a side view of one of Westons
differential pulley blocks with our Invention added. Figure 2. represents a front
view of the same pulley block with our Invention added. Figure 3. represents two
of the added wheels or rollers with the extended or projecting curves by which the
corresponding arms of the frame on either side are joined together. It also shews
the axis upon which such two rollers revolve. The letters A. in the Drawings
herewith represent and shew the wheels or rollers or parts of them whilst the
letter B. represents the curved frame by which the corresponding arms of the pulley
block are united and the letter C. represents the axis upon which such wheels or
rollers revolve. The form of the wheels or rollers before referred to and used in
our Invention is shown by Figure 3. and their position when added to one of

page_text: Westons differential pullies is shewn by Figures 1. and 2. the wheels or rollers
in each Figure being marked A. The letter D. in Figure 3. shews the groove the
letters E. E. the curves and the letters F. F. the projecting edges in each wheel or
roller. These wheels or rollers when fixed to the differential pulley are so spaced
from the differential pulley that the curved part on either side of the groove of
cach wheel or roller just misses, the teeth of the differential pulley some of which
teeth are shewn in Figure 2. by the letter G. When these wheels or rollers are
fixed at the front and back of the pullies as shewn in Figures 1. and 2. the chain
by which the pulley is worked passes between each wheel or roller and the
differential pulley. Such of the links of the chain as when passing should lie flat
and fit in the teeth of the differential pulley are if they are twisted or out of place
forced into their proper positions by the projecting edges marked F. F. in Figure 3.
of the rollers A. there being sufficient space only for such links to pass the
projecting edges when properly fitting in the teeth of the differential pulley and
such links as when passing between the wheels or rollers A and the differential
pulley should stand on their side in the groove of the differential pulley and in the
groove marked D. in Figure 3. of the wheels marked A. are by the conformation of
the wheels or rollers and the teeth and groove of the differential pulley forced into
their proper position that is to say in the groove of the differcutial pulley and the
groove marked D. in Figure 3 of the wheels or rollers A. and unless all such links
are engaging the teeth or groove of the differential pulley and are in their proper
places they cannot pass the wheels or rollers A.-
Having described the nature of our Invention and also the manner in which
the Invention is to be worked we claim as our Invention the improvement for
guiding the chain on to differential pulties hereinbefore particularly described or
illustrated in the Drawings accompanying this, that is to say; the addition-to-and-
combination with differential pullies or pully blocks of revolving wheels-or rollers
grooved edged and curved, tho curves of which wheels or rollers correspond with
the curves of the teeth of the differential pulley and when revolving closely but
freely pass such curved teeth, and so spaced and fixed to the pulley block that the
groove edge and curve of each wheel or roller allow only sufficient space for the
chain when engaging the teeth and groove of the differential pulley to pass between
it and such wheels or rollers thus forming a guide for the loops of the chain working
the differential pulley the same being constructed and worked for the purposes
and substantially in mannor herein before and in the accompanying Drawings
particularly described or shown.