Improvement in Capstans.
Year: 1892

page_text: Date of Application, 20th May, 1892-Accepted, 30th July, 1892
Improvement in Capstans.
I, FRANK STEAD MANTON, of No. 105 Prospect Street, in the City of Providence,
in the County of Providence, State of Rhode Island, United States of America,
Mechanical Engineer, do hereby declare the nature of this invention, 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 reference to improvements in the construction of ship capstans,
and consists in the peculiar and novel combination and arrangement of the several
co-acting parts, whereby the maximum of strength and efficiency is secured with
the minimum of cost, and the capstan-barrel may be driven through intermediate
gears with increased power in one direction and driven in the opposite direction at
increased speed.
In the use of capstans on board a ship, anchors and other heavy weights are
raised and after reaching a certain height require to be lowered,-lines are also
frequently drawn in, in warping or otherwise manipulating the ship, which at times
have to be cased off, or paid out, without cutting the lines or casting the same off
from the capstan. When drawing in the line or raising the weight greater power
is required than in paying out or lowering; by the peculiar construction of my
improved capstan this can be readily done at increased speed by reversing the
movement of the capstan-head.
Figure 1 is a vertical transverse sectional view of my improved capstan, the
spindle being shown in view.
Figure 2 is a horizontal cross-section on a line immediately above the inter-
mediate pinion-gears.
Figure 3 is a side view of the capstan-head part of which is shown broken away
so as to illustrate the construction of the pawl and the operating-lever by which the
same is raised and lowered to connect or disconnect the capstan head and the barrel.
In the drawings the base 4 is provided with the circular channel 5 having radial
ratchets with which the usual retaining-pawls, pivoted to the capstan-barrel,
engage; these pawls are shown in broken lines in Figure 2. The annular rim 6
extends upward above the lower annular projection of the barrel 7 and forms a
circular chamber in the bottom of which the channel 8 having radial ratchets is
formed. The base 4 has in its centre the substantial boss 9 in which the spindle 10 is
rigidly secured. The base is strengthened by means of the deep radial-ribs 11
extending from the central-boss 9 to the outer rim of the base, three or more
ribs 11 are used so as to secure a firm and rigid base, the whole being cast in one
piece. Within the circular space, surrounded by the rim 6, is placed the disk 12
journaled on the spindle 10. In the disk 12 the vertically-sliding gravity-pawls 13
are mounted in vertical slides; these pawls 13 engage with the ratchets in the
annular-channel 8 and hold the disk 12 against rotation in one direction while they
permit the disk to turn in the opposite direction, the pawls being raised by the
-inclined surfaces of the ratchet-teeth. The stud-pins 14 are rigidly secured in the
disk 12 and form the shafts on which the pinion-gears 15 revolve, to reduce the
friction the pinion-gears are lined with Babbitt or other anti-friction metal. On
the spindle 10 is placed the gear 16; this gear is provided with the anti-friction
metal-bearing 17 of considerable length so that the gear has a firm bearing on the
spindle and yet may be easily turned thereon. The upper part of the gear 16
is provided with the cylindrical projection 18 the outer surface of which is finished
so as to form a bearing for the barrel 7 the weight of which is supported on the
flange 19. The cylindrical upper portion of the gear 16 is formed into clutch-
recesses into which the clutch-projections 20 of the sleeve 21 enter.
The sleeve 21 forms part of the capstan-head 22;-the sleeve is provided with the

page_text: bearings 23 which encompass the spindle 10, so that the sleeve and capstan-head
turn on the spindle. The collar 24 is firmly secured to the upper end of the
spindle 10, the whole is protected by the cover 25 which rests on the capstan-head 22
and turns with the same. The capstan-head is provided with the usual capstan-bar
sockets 26 and is also provided with the vertically-sliding pawl 27 on which the
stop-block 28 is formed by which the upward motion of the pawl is limited. The
hand-lever 29, pivotally connected to the capstan-head at its inner end, projects
through the slot 30 in the capstan-head,-in the edge forming the upper margin of
the slot 30 the notches 31 are formed and the lever 29 is provided with raised
projections which enter these notches 31 and hold the lever 29 in the two opposite
positions. The pawl 27 connects with the annular ratchet 32, formed on the upper
surface of the barrel 7, so that, when the pawl is permitted to drop, the capstan-
head and the capstan-barrel turn together, and, when the hand-lever 29 is moved
under the beveled end of the pawl 27 so as to raise the same, the capstan-head is
free to turn independent of the capstan-barrel, and the capstan-barrel may be
driven by means of the spindle and the gears between the said spindle and the
teeth on the inside of the capstan-barrel.
The capstan-barrel has its bearings on and turns on the cylindrical surface of the
sleeve 21 at its upper end, and on the cylindrical projection 18 of the gear 16 at its
lower end; these bearings 33 are made of Babbitt or other similar anti-friction
metal.
.1
By the peculiar construction herein described, firm and rigid bearings are secured
for the operative parts of the capstan, and, by reason of the facility with which the
capstan-barrel can be connected with and disconnected from the capstan-head, can
be turned at less speed with increased. power through the gears, or with greater
speed directly from the capstan-head. The capstan can be used more quickly and
efficiently, than capstans as heretofore constructed, under such emergencies as
frequently present themselves on board a ship, when the safety of the ship depends
on the prompt action of the capstan.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
Claim 1. A capstan, consisting of the base provided with two annular ratchets
and having a central spindle firmly secured thereto, a disk provided with one or
more pawls and one or more pinion-gears, a barrel provided at its lower end with
gear-teeth and at its upper end with an annular ratchet, a capstan-head having a
vertical pawl adapted to engage with the annular ratchet on the capstan-barrel, a
hand-lever adapted to raise and lower the pawl and a central sleeve connecting the
capstan-head with the central-gear, and a collar secured to the spindle, all the
bearings of the capstan being formed of Babbitt or other anti-friction metal, as
described.
2. In a capstan, the combination with the base, the barrel, the capstan-head, and
the spindle forming the central column of the capstan, of the disk 12, the pinion-
gears 15, the gear 16, the gear on the lower end of the capstan-barrel, and the
sleeve connecting the gear 16 and the capstan-head, of the ratchets 8 and 32, the
pawls 13 and 27, and the hand-lever 29 adapted to connect or disconnect the capstan-
head and barrel and drive the barrel either directly, or through the intermediate-
gears, as described.
cul
AD 2000
FRANK STEAD MANTON.
Haseltine, Lake & Co.,
4
45, Southampton Buildings, London, Agents for the Applicant.