IMPROVEMENTS IN CAPSTANS
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by the said Thomas Roberts at the
Office of the Commissioners of Patents on the 24th May 1877.
THOMAS ROBERTS, of Newlyn, in the County of Cornwall; Ironfounder.
"IMPROVEMENTS IN CAPSTANS."
My Invention consists in constructing capstans, so that instead of working on a
dead neck and collar or brass bushing on the capstan spindle as hitherto, they work
on balls of, brass or other metal placed in a groove in a collar fixed to the capstan
spindle; the boss of the wheel or a washer fixed thereon is formed with a groove
corresponding to the first-named groove to fit over the balls. By this arrangement
the friction during the rotation of the capstan is much reduced. The collar and
the wheel or washer thereon are held together by screws, passed through holes in
a flange on the collar into a groove in the wheel or washer.
The Invention also consists in the introduction of antifriction rollers between
the boss of the wheel and the capstan spindle, so as to reduce the friction at the top
bearing of the capstan. The bottom bearing is provided with similar rollers as in
some capstans now made.
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page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Roberts in the Great Seal Patent Office on the 24th November
1877.
THOMAS ROBERTS, of Newlyn, in the County of Cornwall, Ironfounder.
"IMPROVEMENTS IN CAPSTANS."
My Invention consists in constructing capstans, so that instead of working on a
dead neck and collar or brass bushing on the capstan spindle' as hitherto, they work
on balls of brass or other metal placed in a groove in a collar fixed to the capstan
spindle; the boss of the wheel or washer fixed thereon is formed with a groove
corresponding to the first-named groove to fit over the balls. By this arrangement
the friction during the rotation of the capstan is much reduced. The collar and the
wheel or washer thereon are held together by screws, passed through holes in a
flange on the collar into a groove in the wheel or washer.
The Invention also consists in the introduction of antifriction rollers between the
boss of the wheel and the capstan spindle, so as to reduce the friction at the top
bearing of the capstan. The bottom bearing is provided with similar rollers as in
some capstans now made.
•
Figure 1 of the annexed Drawings is a vertical section of a capstan constructed
with my improvements.
A is the spindle, and B the wheel of the capstan ; C is a collar of iron or other
metal fixed to the spindle A, and formed on its upper face with a groove in which
balls E, E, of brass or other metal are placed; F is a washer of iron or other metal
fixed to the boss of the wheel B, and formed on its under face with a groove to
correspond with the groove in the collar C and to fit over the balls E, E. The
collar C and the wheel B are held together by screws H, H, passed through holes
in a flange I on the collar into a groove in the washer F; L, L, are antifriction
rollers between the boss of the wheel B and the spindle A, for the purpose of
reducing the friction at the top bearing; M is a wire let into a groove in the
wheel B to keep the rollers L, L, in place; N, N, are antifriction rollers at the
bottom bearing...
Figure 2-represents a modified arrangement of the top bearing. Similar letters
to those in Figure 1 indicate corresponding parts.
And, having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim as my "Improvements in
Capstans,"
First. Constructing capstans so that they work on balls, substantially as herein-
'before described and represented in the annexed Drawings.
1:
Second. Constructing capstans with antifriction rollers at the top bearing, sub-
stantially as herein-before described and represented in the annexed Drawings.
Third. The general arrangement or combination of parts of capstans, as herein-
before described and represented in the annexed Drawings.
In witness whereof, I, the said Thomas Roberts, have hereunto set my hand
يه
and seal, this Twenty-first day of November, One thousand eight hundred
and seventy-seven.
MITTA