Improvements in Friction Clutches.
Year: 1898

page_text: Improvements in Friction Clutches.
RICHARD NUTTALL, Engineer, 4, Garden Street, Tottington, Bury, Lancashire,
HUGH PORRITT ROBERTS, Bleacher, Tottington Hall, Bury, Lancashire, do hereby
declare the nature of this invention to be as follows:-
The clutch consists of an outer shell, pulley, or drum running loose on a shaft
with an expanding interior fast on the shaft. The interior is composed of a block
with 3 arms equi-distant on which are 3 sliding segments and 3 screws, each with
right & left hand threads fitted into 6 nuts one of which is attached to each end
of each segment. There is also a sliding block on the shaft with 3 links, equi-
distant coupled to the 3 screws. By this means the interior can be expanded
so as to cause it to grip the inner side of the outer portion of the clutch. The nuts
& screws are fitted to the segments so that the centres of the screws are equi-
distant from the outer & inner edges of the segments, thus avoiding canting
when such segments are pressed outwards to grip the outer shell.
The nuts can be adjusted so as to regulate the expansion of the inner body.
The segments when expanded grip the whole inner circumference of the outer
body with the exception of 2 inches as a maximum. By this method of construc-
tion the inner body grips a larger proportion of the inner circumference of the outer
body than in clutches as usually made and the grip is equal and uniform at all
parts of contact.
Dated this 13th dow of Anil 1808
RICHARD NUTTALL.
HUGH PORRITT ROBERTS.
RICHARD NUTTALL, Engineer, Garden Street, Tottington, Bury, Lancashire,
HUGH PORRITT ROBERTS, Bleacher, Tottington Hall, Bury, Lancashire, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
This invention relates to an improved friction clutch for driving purposes, or
same may be used as a detachable coupling between two shafts working in the
same line.
The nature of said invention & the manner in which same is to be carried into

page_text: practical effect will be readily understood on reference to the sheet of drawings
hereunto annexed & the following explanation thereof
Figs. 1 & 2 are respectively part sectional front & side elevations of the clutch
as applied for driving purposes, & which consists of an outer shell, pulley or
drum A, revolving loose on shaft B, the boss of said shell A being bushed with
brass or other suitable antifriction metal. The outside diameter of
this boss being turned to receive driving pulley or wheel C, which
is securely keyed on said boss.
The inside periphery of shell A is turned full across its face, to receive the in-
ternal expanding segments D. These segments, which are three in number, have
each a suitable boss or socket cast on same, which is bored to slide on circular
turned arms or shanks E cast on centre block F, this block being keyed on centre
shaft B.
The segments D are turned on their outside periphery to fit inside drum A, &
are, by means of the right & left handed screws G, made to expand outwards
from centre of shaft B, to fit inside shell A, or to contract inwards towards shaft B,
so as to be clear of interior of shell A.
The screws G, are of the same number as segments D & have plain preparation
in centre & a right hand thread on one end and a left hand thread on the other
end, a rotating lever H being securely fixed on the plain part of each screw, or
for preference, the screws G with levers H, may be made in one solid piece. Each
threaded end of each screw to work in bush I, made from brass or other suitable
material, these bushes I being fixed in suitable preparations cast on each end of
segments D & held in position by means of the caps J, & bolts K. The levers H,
& consequently screws G, are actuated by means of the grocved sliding block L,
which is coupled up to the levers H by means of the links M.
Figs. 3 & 4 are respectively part sectional front & side elevations of friction
clutch used as a detachable coupling between two shafts working in the same line,
the shell A in this case being keyed on the centre shaft B, & the centre boss, or
block is keyed on the independent shaft B.
Referring again to Figs. 1 & 2, the clutch is here shewn in gear; that is, the
internal expanding segments D, are pressed against the interior of shell A: whilst
in Figs. 3 & 4, the clutch is shewn out of gear; that is, with the internal seg-
ments D drawn clear away from inside of shell A. These two positions of the
inner segments D are obtained by manipulating the sliding block L, which works
on a feather key fitted in shaft B & consequently revolves along with shaft B,
the clutch being put in gear by sliding the block I, by suitable mechanism, from
the position as shewn in Fig. 4, to the position shewn in Fig. 2, nearer to the
centre block F. This sliding motion, through the links M & levers H,
imparts a rotary motion to screws G which turn in the bushes I and these bushes I
being firmly fixed in each end of segments D, these segments, sliding on arms E,
are pushed diametrically outwards from centre shaft B & made to grip the inside
periphery of shell A.
The nuts I are fixed in the centre of the width of face of segments D & the thrust,
arising from the. screws G, 'is consequently even across the face of said segments.
When the clutch is put out of gear, the sliding block L is drawn away from
boss F & the segments D are consequently drawn clear away from internal peri-
phery of shell A. By reason of the peculiar construction of this clutch, when same
is in gear, the inner segments D grip & exert an equal pressure on the whole inner
surface of the shell A, with the exception of the very small space between each
segment, thus obtaining the full benefit of the gripping surface available. When
the clutch is out of gear, the segments D are withdrawn an equal distance from
shell A, all round the circumference, thus allowing the outside shell to run clear;
& when the internal segments D are in this position the bottom edge of sockets,
sliding on arms E comes in contact with a facing at bottom of said arms, as at X
Fig. 4, the whole of the segments being thus rigidly & compactly supported from
centre block F. The bushes I are provided with holes, so that they may be

page_text: turned round by means of a "tommy key" & the diametric position of segments
regulated.
Figs. 5 & 6 are enlarged views shewing the method of securing the bushes I in
the preparations cast on segments D. These bushes I are turned externally &
are placed in grooved preparations cast on segments, these preparations having a
recess O cast in with narrow bearing surface at collar end of bush I. White metal
or other suitable alloy is run into the recess 0 round the bush, up to its centre
line. The cap J is then placed on the top half of bush I, one end of the cap fitting
under a lip cast on segment D, the other end being securely bolted to prepara-
tion cast on segment D by means of bolt K.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:-
Firstly. An improved friction clutch to be used either for ordinary driving or
as a detachable shaft coupling, & having an outside shell & an adjustable interior,
consisting of 3 regulatable segments, centre block, nuts, screws, levers & fixings
peculiarly arranged so that, when clutch is in gear, the interior grips & exercises
an equal pressure on a maximum of the inner surface of outer shell; & when out
of gear, the interior is an ample & equal distance away from the outer shell & is,
in this position, compactly sustained from centre shaft.
Secondly. The peculiar method of fixing bushes in ends of segments, in connec-
tion with clutches forming the subject matter of the first claim."
All substantially as described and set forth.
Dated this 18th day of June 1898.