Improvements in and relating to Clutches.
Year: 1895

page_text: Date of Application, 4th June, 1895-Accepted, 20th July, 1895
COMPLETE SPECIFICATION.
Improvements in and relating to Clutches.
I, ERASTUS WOODWARD, a citizen of the United States of America, residing
at 32 Wigglesworth Street Somerville, County of Middlesex, and State of
Massachusetts, one of the 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:-
My invention has for its object to produce an improved friction movement by
which a shaft can be connected to and disconnected from the driving pulley, which
gives it motion, and my invention consists of certain novel features, arrangements
and combinations hereinafter described and particularly pointed out in the claims.
In the accompanying drawings which form a part of this application;
Figure 1 is a side elevation of the shaft with the driving pulley and other parts
in section.
Figure 2 is an end view of Figure 3, looking in the direction indicated by the
arrow shown in Figure 3.
Figure 3 is a central longitudinal section through the engaging block, by means
of which the driving pulley and shaft are connected.
Figure 4 is a side view of the shaft, driving pulley and connecting part,
showing the location of the parts when the shaft is disconnected from the driving
pulley, and with the releasing device in its upper position to
disconnection.
cause said
Figure 5 is a cross-section on the line --, Figure 4 and showing the releasing
device by which the driving pulley and shaft are disconnected.
Figure 6 is a side elevation of a portion of the shaft, driving pulley, engaging
block and releasing device by which the driving pulley and shaft are disconnected,
and showing the position of the parts, when the shaft and driving pulley are
connected with the releasing device in its lower position.
Like letters of reference refer to like parts throughout the several views.
In the drawings A represents the shaft to which power is to be applied, and at
one end it has a portion A¹ of diameter less than the main portion, and beyond
that portion A¹ there is a continuation A2 of further reduced diameter, and at the
opposite end there is provided a crank shaft A', by which the motion of the
shaft A is communicated to perform work.
On the portion A2 of the shaft A there is loosely mounted the driving pulley B,
and the hub thereof is provided with a rearward extension B' extending outwardly
and contacting with a washer B2 secured to the end of the shaft by a screw or
other suitable device, and said hub has an inward extension B³ which contacts with
and bears against the shoulder of the portion A. of the shaft A. In the inner
face of the driving pulley B there is provided a circular groove B*, in which the
engaging block C is adapted to move inwardly and outwardly, and when in its
inner position, as shown in Figure 6, forms a fixed clutch with the pulley B.
On the portion A' of the shaft A there are arranged four spirals C', which
are spirally arranged from the front to the back of said portion. On the interior
of the engaging block C there are provided two threads C², which extend a little
over one-half the length of the engaging block, and two threads C³, which are
about one-half the length of the threads C². These threads are adapted to fit
in between the spaces formed between the spirals C₁ on the portion A¹ of the
shaft, and in the spaces where the half spirals fit there are two spiral springs D,

page_text: which bear against one end of each half spiral, and at the other end against
the upper end of the space formed between two of the spirals (see Figure 1) and
the tendency of said springs is to cause the unwinding of said engaging block
from the spirals C₁ and move it into the recess B, so that the engaging block
fits tightly in the recess or groove B of the driving pulley B, and power is
thereby communicated from said pulley B to the shaft A to cause the revolution
of the same.
On the outer periphery of the engaging block C there is arranged a lug E,
the purpose of which is to disengage the engaging block C from the friction
connection with the driving pulley B, and thereby stop the operation of the
shaft A. This lug E is adapted to operate with the releasing device F, connected
to and operated by a lever G extending downwardly and operated by a suitable
foot lever or treadle or other means. This releasing device F is pivoted on the
shaft H secured in the frame of the machine, and extends forwardly and is provided
with two forwardly extending arms F1, and F2, and to the forward end of the
arm F the operating lever G is pivotally connected at F3. With the shaft A
and driving pulley B connected and the shaft in operation, as shown in Figure 6,
if it desired to disconnect the driving pulley and shaft, the foot is removed
from the lever and the rod G and the releasing device F, with its arms F1 and F2,
move upwardly on the pivot H from the position shown in Figure 6 to the
position shown in Figures 4 and 5, and in the revolution of the pulley B and
engaging block C on the shaft A, the lug E comes in contact with and moves along
the inclined side F4 of the arm F', and owing to this contacting of the lug E and
arm F the engaging block C is unwound from connection with the driving pulley B
and the power of said pulley is not communicated to the shaft A.
With the parts as shown in Figures 4 and 5, the shaft A and pulley B are
disconnected and no power is transmitted from said pulley to the shaft, but when it
is desired to cause the connection of said shaft and pulley the operator, pressing on
a suitable foot treadle, pulls down the rod G with the releasing device and its
arms F and F2, and as the arm F' passes down from its contact with the lug E,
leaving said lug entirely free, the springs D, arranged between the spirals on the
shaft and engaging block, exert their teusion on said engaging block and at once
screw it up into the recess B of the pulley B, and as said engaging block unscrews
and pinches into the recess B4 of said pulley B, the more you turn the pulley the
more the engaging block tries to unscrew, and by this means the two form a fixed
friction clutch, the tendency of which is to unscrew said pulley rearwardly, but as
it cannot be unscrewed from said shaft owing to the washer B2 on the rear of the
shaft, it carries the shaft with it, and the shaft is kept in revolution until the
releasing device F is allowed to assume its upper position, shown in Figures 4
and 5, when the lug E, in the revolution of the engaging block C, coming in
contact with the releasing wedge shaped arm F, stops the revolution of said
engaging block and the shaft screwing on to the end unloosens it from the
pulley B and moves said engaging block from its friction connection with said
pulley B, and the operation of the shaft A is stopped.
I do not limit myself to the arrangement and construction shown, as the same
may be varied without departing from the spirit of my invention.
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 clutch mechanism, a driving pulley, a shaft adapted to be connected to
and disconnected from said pulley, an engaging block mounted on said shaft,
nechanism suitably controlled for preventing the engagement of said block and
pulley, and independent automatic mechanism for engaging the block and pulley
upon the operation of said controlled mechanism.
2. In a clutch mechanism, a driving pulley, a shaft adapted to be connected to
and disconnected from said pulley, an engaging block loosely mounted on said

page_text: shaft and having a screw thread engaging with a corresponding screw thread on
the shaft, mechanism suitably controlled for preventing the engagement of said
block and pulley, and independent automatic mechanism for engaging said block
and pulley upon the operation of said controlled mechanism.
3. In a clutch mechanism, a driving pulley, a shaft adapted to be connected to
and disconnected from said pulley, an engaging block mounted on said shaft,
mechanism suitably controlled for preventing the engagement of said block and
pulley, and a spring bearing against said block and held under tension by said
mechanism and adapted upon the operation of said mechanism to move said block
into connection with said pulley.
4. In a clutch mechanism, a driving pulley, a shaft adapted to be connected to
and disconnected from said pulley, an engaging block mounted on said shaft and
having a screw thread engaging with a corresponding screw thread on the shaft,
mechanism suitably controlled and contacting with said block for preventing the
engagement of said block and pulley, and independent automatic mechanism for
engaging said block and pulley upon the operation of said controlled mechanism.
5. In a clutch mechanism, a driving pulley, a shaft adapted to be connected to
and disconnected from said pulley, an engaging block mounted on said shaft and
having a screw thread engaging with a corresponding screw thread on the shaft,
niechanism suitably controlled for preventing the engagement of said block and
pulley, and independent mechanism for engaging said block and pulley, after
the operation of said controlled mechanism.
6. In a clutch mechanism, a driving pulley, a shaft adapted to be connected to
and disconnected from said pulley, an engaging block mounted on said shaft,
mechanism suitably controlled for preventing the engagement of said block and
pulley, and independent mechanism for engaging the block and pulley after the
operation of said controlled mechanism.
7. In a clutch mechanism, a driving pulley, a shaft adapted to be connected to
and disconnected from said pulley, an engaging block mounted on said shaft,
mechanism suitably controlled for preventing the engagement of said block and
pulley, independent mechanism for engaging the block and pulley after the
operation of said controlled mechanism, and a lug on said block adapted when
contacting with said controlled mechanism to move said block from engagement
with the pulley and thereby disengage the shaft and pulley.
8. In a clutch mechanism, a driving pulley, a shaft adapted to be connected to
and disconnected from said pulley, an engaging block mounted on said shaft and
normally tending to engage with said driving pulley, mechanism suitably controlled
for preventing the engagement of said block and pulley, and independent
mechanism for engaging the block and pulley after the operation of the said
controlled mechanism.
Dated this 4th day of June 1895
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.