IMPROVEMENTS IN FRICTION CLUTCHES
Year: 1887

page_text: I, IRVIN GILBERT HOOPER, of Newark, County of Essex and State of New Jersey,
United States of America, Engineer, do hereby declare the nature of my invention
for "IMPROVEMENTS IN FRICTION CLUTCHES" and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
The general class of inventions to which my improvement relates is friction-clutches
provided with expanding frictional surfaces which are caused to move outwardly by
means of suitable mechanism and bind against the inner peripheral surface of a
pulley or gear-wheel, and is designed to secure a friction-clutch that is more
positive and prompt in binding and in releasing the pulley or gear-wheel, which may
be easily adjusted to take up the wear, and which secures an increased frictional
surface.
In the accompanying two sheets of drawings, in which similar reference-letters are
employed to indicate corresponding parts in each of the, views, figure 1 is a front
elevation of a drum of a hoisting-machine to which is attached my improved clutch
mechanism. Figure 2 is a section of the same, taken through line. Figure 3 is a
longitudinal section of said drum, taken through line y, figure 2. Figure 4 is a
similar view through line 2, figure 2; and figure 5 is a longitudinal section of an
adjusting-cap with the end of the threaded plunger or actuating rod inserted therein.
On sheet 2, figure 6 is a view similar to figuro 2, illustrating a different construction
of the toggle-joints. Figure 7 is a view similar to figure 4, showing the clutch
mechanism in an expanded holding position. Figure 8 illustrates the manner of
fastening the friction ring, and figure 9 is a plan view of one of the springs used for
releasing the frictional surfaces.
In the drawings, A indicates the drum of the hoisting-machine which turns loosely
on a hollow shaft, a, which is journaled in suitable hearings, al, as illustrated in
figure 1. In one end or face of the drum is a recess, a³, in which is arranged a
reciprocally-sliding collar, b, having an inclined or beveled surface, b, which engages
with a correspondingly inclined surface on the blocks c, to which the rods
pivotally attached, forming a toggle-joint. (Shown in figure 2.)
are
A recessed gear-wheel, D, keyed on the hollow shaft a, is arranged close to the

page_text: recessed face of the drum, and in the space between said drum and gear the clutch
mechanism is placed, which, in addition to the beveled blocks and collar alread y
described, consists of segmental expanding plates E, provided with broadened flanges e
on the outside thereof, which form frictional surfaces, which, when said segmental
plates are thrown outwardly, engage with the inner peripheral surface, d, of the gear-
wheel, or with an interposed ring of vulcanized fiber, f, or other suitable material,
arranged between the said plates and gear-wheel, as shown in figures 2 and 6. The
rods c, which are pivoted to the blocks c are also pivotally attached to the segmental
plates, and when the toggle-joint is straightened by the engagement of the sliding
collar with the blocks c the effect is to throw the segmental plates into frictional
contact with the gear or ring of fiber.
In the segmental plates are slots e, in which are arranged slotted angle-plates a³,
which are adjustably secured to the recessed face of the hoisting-drum, and which servo
the double function of causing the said plates to turn with the drum, while at the same
time permitting the necessary outward movement of the plates, and also the projecting
portion a³ of said angle-plates provides a fixed stop, against which the springs e² bear
at their central point, being held at their extremities by the lugs e on the segmental
plates, as in figure 2.
When by the action of the toggle-joints the segmental plates are thrown into
holding engagement with the gear-wheel or fiber and then released from said
engagement, the springs e act immediately to draw the said plates inwardly away from
the frictional contact with the gear or -fiber, as will be understood by reference to
figures 2 to 7.
Springs a, secured to the drum by pins a, are placed contiguous to and bear
against the top of the blocks c, and co-operate with the springs e to quickly and
positively cause the separation of the frictional surfaces. As illustrated in figures 2
and 6, the rods c are pivotally secured to the segmental plates and the blocks c by
forming annular recesses and therein, portions e and c thereof being cut away to
permit the movement of the rods, und in said recesses the rounded ends c' of the rods
are placed, and held between the face of the segmental plates and the inner flat faco
of the gear-wheel without the use of any other means of fastening the same, as will
be understood by references to figures 2 and 3, the latter figure showing the annular
recesses only, the rods being omitted from said view.
In figure 2 the annular recesses are formed on opposite sides of the blocks c, and aro
independent one of the other, while in figure 6 the annular recess is formed centrally
in the block, and the rounded end c¹ of ono rod fits within the recessed end c* of the
other of the rods.
The mechanism for producing the forward movement of the sliding collar toward
and against the inclined surface of the blocks c consists of a rod, g, arranged within
the hollow shaft, as illustrated in figure 3, one end of said rod bearing against a
plate g', moving in a slot, g², in the hollow shaft, which bears against the sliding
collar or against a washer, 63, figures 3 and 4, the opposite end of said rod projecting
from the hollow shaft and provided with an adjustable cap, g³, which screws upon
the end of the rod, as indicated in figure 5. Adjacent to the cap and pivotally
arranged in an arm, ', is a cam-lever, 9, having a rounded end or portion, 9,
which engages the said cap when the lever is depressed and forces the rod
forward, causing thereby the sliding movement of the collar and its engagement with
the blocks c.
By means of the adjustable cap the degree of pressure may be regulated, and as the
parts become worn they may be adjusted to compensate for the lossa point of great
value in friction-clutches.
Springs baro arranged between the end of the sliding collar and the gear-wheel,
as indicated in figures 4 and 7, the former figure showing the expanded position of
said springs and the latter the compressed position thereof when the sliding collar has
been moved forward to cause the frictional engagement of the segmental plates and
gear-wheel. Upon the release of the collar said springs act to force said collar
backward away from the blocks, and thus co-operate with the springs e and a to

page_text: return the several parts of the clutch to their normal disengaged position, as shown in
figures 2, 3, and 4.
The interposed ring f, which may be in one or in several pieces, and may be of
fiber, copper or any other suitable material, is placed between the fixed and expanding
or movable frictional surfaces of the clutch, and is held in place by inserting a
straight or tapering pin; f', in an opening made where the ends of the ring join, by
means of which the ring is spread outwardly and caused to bind the inner peripheral
surface of the gear, as will be understood by reference to figure 2. By this arrange-
ment of an interposed ring double frictional surfaces are secured, which is of manifest
advantage.
'
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 :-
1. In a friction-clutch, the combination of a recessed gear-wheel, segmental plates
arranged oppositely within said recessed gear-wheel and adapted to engage with the
inner peripheral surface of said gear-wheel, toggle joints connecting said oppositely
arranged segmental plates, consisting of rods c¹ and blocks c, having inclined surfaces,
a sliding collar provided with an inclined surface, 61, which engages with the inclined
surfaces on said blocks c, mechanism constructed and arranged to cause engagement
of said collar and blocks, and springs engaging with said seguiental plates, blocks c,
and sliding collar, substantially as and for the purposes set forth.
2. In combination, a hoisting drum; a hollow shaft on which said drum turns;
a gear-wheel keyed on said shaft adjacent to said drum, the cogged periphery of which
projects toward said drum, providing a recess therebetween; segmental plates E,
arranged oppositely in said recoss and adapted to engage with the inner peripheral
surface of said gear-wheel, and provided with slots e', therein; toggle-joints connecting
said oppositely arranged plates, consisting of rods c and blocks c, having inclined
surfaces; adjustable angle-plates, arranged in said slots e¹ and secured to the face of
the drum; a sliding collar moving on said hollow shaft, having an inclined surface, b',
which engages the inclined surface of the blocks; springs e, a, and 63, arranged
for the purposes set forth; a sliding rod moving in said hollow shaft, having an
adjustable cap on one end thereof; means arranged to communicate the movement of
said rod to said sliding collar; and a cam-lever engaging with said rod, for the purposes
set forth..
Dated this Fifteenth day of October 1887.