Improved Frictional Coupling for Shafting and the like.
Year: 1886

page_text: Improved Frictional Coupling for Shafting and the like.
I, ANDREAS MECHWART of N° 36 Donatigasse Budapest in the Austrian Empire,
Managing Director, 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 relates to frictional couplings for shafts, wherein cylindrical cheeks
carried by the one length of shafting are pressed against an inner cylindrical
surface on the other length of shafting with sufficient force to effect a frictional
grip between the two.
My improvements have for their object so to construct such couplings that a
maximum amount of frictional pressure shall be attainable by means of a minimum
amount of axial pressure, while ready adjustment is provided for any wear of the
frictional surfaces; both parts of the coupling are fixed upon their shafts, and
either the one or the other can be used as the driving shaft; also the one part of
the coupling serves as bearing for the end of the other shaft.
The above condition of obtaining the maximum amount of frictional pressure
might be fulfilled by means of toggle levers, not however by forming these as
heretofore with an angle of nearly 180° but with a considerably smaller angle, as
otherwise the slightest wear of the surfaces would make the coupling inoperative.
But as with a less obtuse angle the axial pressure would require to be very great,
thereby producing considerable friction in the mechanism by which the axial
pressure was applied, the toggle levers are according to my present invention so
arranged that while the angle formed by the operating lever or link with the axial
line of the shaft is nearly 90°, a ready adjustment is provided whereby that angle
is maintained notwithstanding wear.
The constructions which I employ for this purpose are shewn on the accompanying
drawing. In which Fig. 1 shews a longitudinal section of one arrangement and
Figs. 2 and 3 shew detached details.
A and B are the two lengths of shafting; on A is fixed the part C of the
coupling, the extended boss of which has a cylindrical recess lined with brasses M,
and serving as bearing for the end of the shaft B. On B is fixed the disc D having
guides D¹ for two, or three, frictional cheeks E as shewn at Fig. 2. The boss of D,
carries the sliding sleeve F having two, or three arms F1 Fig. 3, according to the
number of cheeks employed. To these arms are pivotted the toggle levers G H,

page_text: the parts of which are pivotted to the cheeks E, while the parts G are formed
as elbow levers one of the arms of which are connected adjustably to screws k, as
shewn at Fig. 1, whereby the parts H may be made to adjust the cheeks E
relatively to the frictional surfaces of C. If the cheeks E are so adjusted as to be
in contact with C when the levers H are brought by F into a position nearly at
right angles to the axis of the shaft, then the coupling will be effected by a very
moderate axial pressure.
The lubrication of the bearing at M is effected by a grease box as shewn.
In the modification shewn at Fig. 4 the arm G₁ of the elbow lever is formed as
a spring, which is adjusted by the screw k¹ so as to adjust the positions of the
lever Hand cheek E, the cheeks being by this arrangement made to act with
elastic pressure. A straight rigid lever might also be used in place of the spring
lever. In the modification shewn at Fig. 5 the lever G or G¹ is replaced by an
eccentric pin h, to which the lever His pivotted, and which is rotated by the worm
and worm wheel L for adjusting the fulcrum of H'.
It will be readily understood that the above described improved coupling may
also be employed for coupling a loose pulley or toothed wheel to a shaft.
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
1. Constructing the lever mechanism for actuating the cheeks of frictional
couplings in such manner that while the levers or links that effect the frictional
contact of the cheeks with the other part of the coupling are situated nearly at
right angles to the axial line, their fulcra or supports are rendered adjustable by a
screw, eccentric, or equivalent adjusting device to compensate for wear, substantially
as herein described.
2. In frictional couplings such as are referred to in the preceding claim, the use
of levers or links H connected at one end to the cheeks E and at the other end to
elbow levers G, adjusted by means of screws k, substantially as herein described
with reference to Fig. 1 of the drawings.
3. In frictional couplings such as are referred to in the first claim the use of
levers or links H¹ connected at one end to the cheeks E and at the other end to
spring levers G¹ adjusted by screws ¹, substantially as herein described with
reference to Fig. 4.
4. In frictional couplings such as are referred to in the first claim, the use of
levers or links H' connected at one end to the cheeks E and at the other end to
eccentric pins, adjustable by worm and worm wheel gear L, substantially as
herein described with reference to Fig. 5.
ABEL & IMRAY,
.Agents for the Applicant.