An Improved Fly Wheel Brake.
Year: 1893

page_text: Date of Application, 7th Sept., 1893-Accepted, 18th Nov., 1893
An Improved Fly Wheel Brake.
I, LUDWIG LUCKHARDT of Cassel, in the German Empire, Engineer, do
hereby declare the nature of this invention and in what manner the same is to he
performed, to be particularly described and ascertained in and by the following
statement :-
This invention relates to a quick action stopping device for steam engines,
turbines, gas motors, etcetera, which upon the occurrence of accidents, break downs
and other kinds of interruptions in working, may be set in action from any
working place, and which acts upon the fly wheel of the particular motor in such
a way as at once to stop its movement. The device consists of a peculiarly
constructed band-brake which the moment it is released, is pulled by a friction
disc and thereby the periphery of the revolving fly wheel so strongly gripped as
effectually to stop it.
In the drawing
Fig. 1 shews the band-brake of this invention applied to a fly wheel,
Figs. 2, 3, 4, 5, are detail views drawn to an enlarged scale.
A is the fly wheel of a motor, an arrow indicating the direction of motion.
For mounting the band-brake, two firm points are requisite, namely, a supporting
point and a draw point. In Fig. 1, a is the supporting point located on the
left in two frames B, and the draw point located on the right in fork E which
latter is carried by lugs on the fixed bed plate P in such a way that it may
oscillate round pin r. The brake band is formed in two parts which almost
completely enclose the fly wheel, part, or band u, being at bottom and part w, at
top, the latter being provided with a longitudinal rib to stiffen it. The brake
band parts u, w, are not connected direct to each other but both are suspended
from a frame f, g, (Figs. 1 and 5). The top band part w ends in a link frame /
and from this toy there is a draw rod connection v, therefore, if I raise the
frame f, g, not only will the bottom band part u be drawn on but also the top
part w, and brought to bear upon the periphery of the wheel. The revolving
pin o of frame f, g, is hung on pitch chains and these are wound up at the
decisive moment by means of chain wheels i, k. The operation is effected by the
draw disc G the periphery of which has a covering of india rubber or leather.
is shewn in side view in Fig. 2 and in cross section in Fig. 3. It is mounted on
shaft n to turn in fork E clamped in between flange like extensions d, d', of chain
wheels i, k, there being two leather discs at the surfaces of contact.
Whilst chain
wheels i, k, are firmly keyed on shaft n and can only be displaced in an axial
direction the disc (located between them may turn on shaft n when it has
overcome the frictional resistance produced by the clamping which resistance may
be regulated by the two screw nuts m.
It
When, upon the application of the brake, the chain wheels i, k, have drawn the
frame f, g, together with the brake bands upwards, these remain with the pull on
them whilst the disc G having overcome the adjustable frictional resistance keeps
turning until the power of the fly wheel is broken. Fork E is, in the position of
rest held removed from the fly wheel by rod t and in the same position also the
brake bands, which are hung on spring bearers, do not of course contact with the
wheel. Rod is horizontally displaceable in a slot of columu F on the right
hand side of which it has a notch in which engages a pawl or catch which may be
released by an electro magnet placed within the foot of the column. An electric
battery is in connection with the electro magnet and also with the electric contacts
which are located in the working places. The release may also be accomplished
by rope pull or pneumatically.

page_text: The braking operation takes place in the following manner :-
At the moment that an electric contact in a working place is closed, a current
passes through the electro magnet, fork E with friction disc G falls upon the
fly wheel and is at once set in rotation, the pitch chains being thereby wound up
and the balance frame f, g, with the brake bands drawn up. The bottom band u
comes the first to a bearing against the wheel but as the balance frame, y, at the
same moment sinks down at the band can only be slid against by the wheel
without this being firmly engaged or gripped, which effect is only obtained when
the top band w has been brought by rod to bear against the periphery of the
wheel that is to say when the balance frame, g, is loaded equally at both ends.
Therefore, by means of the balance frame I obtain from the band u at the same
moment and with the same power a grip on the lower half of the wheel equal
to that from band w on the upon the upper half of the same, thereby preventing
all back lash.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is :
A fly wheel brake consisting of two braking bands u, w, surrounding the wheel,
the pull on which bands is automatically effected by the rotation of friction disc G
upon the release of fork E, whereupon a balanced pull on the brake bands is
obtained by means of balance frame f. g, in the manner that the bottom band u
cannot firmly grip the periphery of the wheel until the top band also comes to
a firm grip. In this fly wheel brake, the adjustment of the pulling force on the
brake bande, by the friction disc G not being connected direct to chain wheels i
and k, but through flange like extensions d, d', on the said chain wheels which
serve as friction discs, the pressure of the same being capable of adjustment by
nuts working over screw threads, substantially as described and shewn.
Dated this 7th day of September 1893.
CAPITAINE & Vox HERTLING,
89, Chancery Lane, London, W.C., Agents for the Applicant.