Year: 1886

page_text: Date of Application, 2nd Oct., 1886.
Complete Left, 1st Mar., 1887.
Complete Accepted, 1st Apr., 1887.
We, WILLIAM POLLARD and JAMES POLLARD, both of Atlas Iron Works, Burnley,
in the County of Lancaster, Machinists, do hereby declare the nature of this invention
to be as follows :-
This invention is designed to prevent the working back of certain parts composing
friction couplings, and to reduce the lateral pressure and friction upon the slide block,
which actuates such parts, whereby the tendency of the slide block to heat, and the
consequent attention and undue lubrication thereof, are avoided.
These Improvements consist in the employment of a spindle chased with a screw
thread to correspond with a similar thread formed in a hole in the centre of a toothed
wheel, which is mounted upon the spindle, and placed within an annular recess or
limited space, formed in the face of a cylindrical casting. This casting is fixed to the
shaft to be actuated, and around the circumference of this circular casting, are placed
one or more segments of a circle, over which is mounted a drum or gear wheel.
The number of spindles may be increased as may be desired, each being provided with
a similar toothed wheel as the one above alluded to, so that the ends of the spindles may
be moved outwards to actuate the segments, and cause their surfaces to bear equally
against the drum, pulley, or the like, mounted upon the segments.
A Slide block is provided, which may be caused to slide upon the shaft by means
of an hand wheel or lever; and to the said block are fixed adjustable tooth racks,
horizontally disposed, by which the extremities of the spindles may be regulated, so
as to bear equally upon the segments when actuated by the slide block. The racks.
may correspond in number, and gear with each respective wheel of the screw spindles,
in such a manner, that as the slide block is pushed forward upon the shaft, to which
the circular casting is fixed, the racks cause the toothed wheels to revolve and screw
each respective spindle outwardly, causing the segments to bear firmly against and
lock the drum or wheel or the like to the circular casting by frictional contact. Upon
the slide block being withdrawn, the wheels are actuated in a reverse direction, by
which means the screw spindles are drawn inwards to liberate the circular casting and
segments from the drum, pulley, or wheel, which now continues to revolve through
its actuating medium, whilst the shaft and other parts fixed thereto, remain stationary.
Springs may be used to ensure the segments being brought against the circular casting,
when the racks are withdrawn.
Dated this 30th day of September 1886.
THOS. RICHMOND,
Agent for the Applicants.

page_text: Improvements in and relating to Friction Couplings.
We, WILLIAM POLLARD and JAMES POLLARD of Atlas Iron Works, Burnley, in the
County of Lancaster, Machinists, do hereby declare the nature of our invention for
IMPROVEMENTS IN AND RELATING TO FRICTION COUPLINGS, and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement:―
This invention is designed to prevent the working back of the parts composing
friction couplings, so as to relieve the parts from strain and pressure.
The Improvements consist in the employment of one or more spindles, each of
which is chased with a screw thread, to correspond with a similar thread formed
in the hole of a small tooth wheel, one being mounted on each spindle. These spindles
are preferably three in number (but more or less may be used if required) and are
placed equally apart within recesses formed in the face of a cylindrical casting, which is
fixed upon the shaft to be actuated. One end of each spindle projects into a hole in the
boss of the casting; whilst the other, terminating in a V or taper piece protrudes through
an opening formed at the circumference of the cylindrical casting, over which are
placed three segments of a circle, inclining inwards at the ends, to correspond
with the V or taper end of each spindle, which acts between the ends of the adjoining
segments.
A slide block is provided which may be caused to slide upon the shaft, by means of
a lever, or by a screw and hand wheel. To the slide block are fixed adjustable tooth
racks, horizontally disposed. These correspond in number with the tooth wheels
above alluded to, with which they gear, in such a manner, that as the slide block is
pushed forward by the lever or hand wheel, upon the shaft, the racks cause the tooth
wheels to revolve, and screw their respective spindles outwards, causing the segments
to bear firmly against, and lock the drum and circular casting together, by fractional
contact.
When the slide block is withdrawn to actuate the tooth wheels in a reverse
direction the drum becomes loosely mounted upon the segments, and now acts as
a loose pulley or drum; whilst the shaft and other parts fixed thereto remain
stationary.
And in order that our invention may be properly understood, and readily carried
into practical effect, we have hereunto attached the accompanying sheet of drawings,
reference being had to the figures and letters marked thereon; the same letters referring
to the same parts in all the views and figures.
Fig. 1, is a side elevation; Fig. 2 an end view partly in section; and Fig. 3, a
vertical section, taken through the plane of the line Z. Z. Fig. 2, representing a
friction clutch or coupling, constructed in accordance with our invention. A is
a drum, mounted upon segments B, (seen in Fig. 2) surrounding the circular
casting C, secured to shaft D. To maintain the drum in position upon the segments,
the side shields E are provided, one on each side of the circular casting, in which are

page_text: formed three recesses, within each of which is inserted a toothed wheel F, provided
with a rack G, fixed to slide block H by the adjustable nuts I.
A spindle F¹ is screwed into each wheel F; that when the slide block is moved
longitudinally upon the shaft D, by the handle J, the racks G are thrust inwards,
causing the wheels F to revolve, and screw outwards each spindle F1, the taper end
of which, acting respectively between the adjoining segments, expands them equally
against the inner rim A¹ of the wheel or drum A, and locks the parts together by
frictional adherence, which is equal to the duty of transmitting the motion of one
part of the coupling to the other. To release the coupling, the racks are drawn
backwards by the slide block H, through the medium of the handle J, when the
wheels F revolve in a contrary direction, and lower the spindles F against the under
lips of the segments B, which are thereby drawn against the circular
The drag pin K, seen in Fig. 2, provided to assist the we
heads of the spindles F¹, in driving the segments round wit'
when in motion; and to regulate the height of the heads of f'
are adjustable by the nuts I, secured to slide block H, whi
upon a key sunk in the shaft D. For the purpose of remong the racks when
desired from the casting C, the bracket L is first removed, to allow the teeth of the
racks, to be moved out of contact with the teeth of the wheels F.
isting C.
taper ends, or
cular casting
.es F¹, the racks
arranged to slide
Suitable grooves are formed in the segments as seen in Fig. 2, to reduce the weight
of the segments, and to render them flexible when thrust against the inner surface
of the drum. Grooves or recesses are also provided on the inner surface of the
drum, to retain oil, which may be discharged from the frictional surfaces, that
immediately the coupling is thrown into action the oil deposited in the grooves will
be distributed upon the frictional surfaces, which are thus restrained from adhering
too suddenly to each other, and thereby prevent undue shock or strain on the parts
to be actuated.
Having now particularly described and ascertained the nature of our said invention,
and in what manner the same is to be performed, we declare that what we claim is :-
The employment of the racks G, wheels F, and spindles F¹, substantially as shown
and described for the purpose specified.