Year: 1886

page_text: I ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Engineer, do hereby declare the nature of this invention (a communication from
Lucius Dyer, George Stillman Sawyer, and Charles Henry Dyer of Millbridge,
Mecosta, in the United States of America) and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention has relation to sheaves for the passage of a rope sheet or
equivalent through a yard-arm, spar, boom or similar object, and it consists in the
improved construction and combination of parts of a guide-bail for such a sheave,
which will guide the sheet or rope straight to the sheave, preventing it from
becoming jammed at the side of the sheave in the slot, if the rope or sheet is
drawn to one side or the other, thus insuring the free passage of the rope or sheet
over the pulley, as hereinafter more fully described and claimed.
In the drawings,
Figure 1 is a perspective view of a portion of a yard-arm provided with this
improvement.
Figure 2 is a longitudinal sectional view of the same; and
Figure 3 is a perspective view on an enlarged scale of the bail and plate
comprising this improvement.
Similar letters of reference indicate corresponding parts in all figures.
A, indicates the end of a yard-arm, and this yard-arm is provided with the usual
slot, B having the pulley, C, over which the sheet, D, passes journalled within it.
The upper end of the slot is provided with a plate E, which surrounds the slot
and is formed with a downwardly projecting flange, F, which fits against the sides
of the slot, filling out or lining the upper end of the slot.
The plate is provided near the outer end with two pairs of upwardly projecting
perforated lips G, G, one pair at each side of the slot, and the ends of a bail, H,
having its outer end bent at a right angle to its side-pieces has its ends pivotted
upon bolts, I, passing through the perforated lips and through the ends of the bail.
A rectangular frame, J, pivotted with pins K, K, projecting from the middle
of the end-pieces, between the sides of the outer portion of the bail, and this frame
Dis 27

page_text: is provided with two rollers, L, L, which are journalled in the side of the frame
having a space between them sufficient to allow the sheet to pass between them.
It will be seen that any strain from the sail upon the sheet will tilt the pivotted
bail and the rocking frame within the bail, so as to keep the sheet straight with
relation to the sheave, so that the sheet may be hauled home, or may be slackened
without any danger of the sheet chafing or getting caught in the slot by being
drawn towards the side of the slot away from the sheave, as will happen where no
bail and guide rollers are provided the bail and rollers preventing any danger of
the sheet breaking from being cut or chafed and having an undue strain exerted
upon it.
The plate surrounding the upper end of the slot will reinforce this slot and
prevent the strain of the sheet upon the sheave from splitting the yard-arm, the
flange lining the entire top of the slot and bearing considerable of the strain upon
the slot. It follows that this guide bail and rollers may be used in spars, booms,
or any place, where a rope passes over a sheave and is liable to have a strain
exerted upon it transverse to the plane of the sheave, the device being applicable
to any sheave, which is journalled within a slot, or recess in a rigid object and not
in a swivelled or freely moving block.
It is obvious that the application of this improvement is not limited to the yard
arms of vessels, but that it may be employed with equal advantage as out-hauls on
booms of fore-and aft-vessels.
Having now particularly described and ascertained. the nature of the said
invention and in what manner the same is to be performed as communicated to
me by my foreign correspondent I declare that what I claim is,
1. In combination with a sheave journalled in a slot, a flange plate lining the
upper end of the slot and a pivotted frame above the sheave having guide rollers
for the passage of a sheet: as and for the purpose shown and set forth.
2. In combination with a sheave journalled in a slot a pivotted frame above the
sheave having guide rollers in its outer end forming a passage for a sheet or rope;
as and for the purpose shown and set forth.
3. In combination with a sheave journalled in a slot, a bail having its outer end
bent at a right angle to its arms and pivotted at the top of the slot with the ends
of the arms, and guide rollers journalled in the outer bent portion of the bail; as
and for the purpose shown and set forth.
4. In combination with a sheave journalled in a slot, a bail having its outer end
bent outward at a right angle to its arms and having the ends of its arms pivotted
near the outer end of the slot, a frame having its ends pivotted between the bent
portion of the bail, and guide rollers journalled in the pivotted frame; as and for
the purpose shown and set forth.
5. In combination with a sheave journalled in a slot, a plate having a down-
wardly projecting and lining the upper end and the edges of the slot and provided
with two pairs of upwardly projecting lips, a bail having its outer end bent at a
right angle to its arms and having the ends of the arms pivotted between the lips,
a rectangular frame having trunnions at its ends pivotted in the sides of the bent
portion of the bail and two guide-rollers journalled in the sides of the pivotted
frame forming a passage for a sheet or rope; as and for the purpose shown and
set forth.