Improvements in Friction Couplings.
Year: 1898

page_text: Date of Application, 5th Aug., 1898-Accepted, 10th Sept., 1898
COMPLETE SPECIFICATION.
Improvements in Friction Couplings.
I, JASPER WETTER, Patent Agent, of 37 and 39, Essex Street, Strand, in
the County of London, do hereby declare the nature of this invention, a
communication from abroad by the Elektrizitäts-Aktiengesellschaft vormals
Schuckert & Co., Electrical Engineers, of Nürnberg, Bavaria, to be particularly
described and ascertained in and by the following statement:-
This invention relates to friction couplings actuated by centrifugal force and has
for its object, to render such couplings suitable for use with shafts revolving at a high
speed.
In the accompanying drawings:
Fig. 1 is a longitudinal section of a shaft coupling embodying this invention,
Fig. 2 is a cross section of the same,
Fig. 3, 4 and 5 show modifications on a larger scale.
On the driving shaft 1, (Figs. 1 and 2) is mounted a hollow cylinder or coupling
box 2, and another coupling box 3, of the same dimensions as (2) faces this on the
opposite shaft (15), or it may be adapted to revolve on the same shaft. Within the
space formed by the two coupling boxes is situated a wheel (5) having in its circum-
ference a series of open cells, which contain rolling weights (4), and a sliding ring (6)
mounted on the driving shaft (1) outside the coupling box (2) is connected with the
said wheel (5) by means of arms (14), so as to support the said wheel and impart
motion to the same.
+
The sliding ring or sleeve (6) is coupled with the driving shaft (1) by means of
groove and feather and has a circular groove (7) for a guide fork, like the movable
clutch of a clutch coupling, by means of which fork the sleeve may be caused to slide
along the shaft (1), so that the cell wheel (5) passes from the interior of one coupling
box into the other. During this motion the weights (4) roll on the inner surface of
the coupling boxes, because the centrifugal force which presses the weights outward
is greater than their friction against the walls of the cells.
The dotted lines in Fig. (1) show the position of the rollers (4), when the coupling
is out of gear, or the driven shaft at rest, while the-full lines show the position, when
the coupling is in gear.
As soon as the weights roll over the edge (8) of the coupling box (3), they slide
temporarily on the inner surface of the box (3), until the latter revolves at the same
speed as the wheel (5).
When the wheel is withdrawn into the box (2), the weights (4) rest against the
inner surface of the latter.
As the operations of coupling and uncoupling cause the weights (4) to roll forward
and backward the same distance, only a small part of their circumference will be
exposed to sliding friction, and the weights are liable to wear out unequally. Special
means have therefore been provided to reduce the wear and tear of the rolling
weights.
As represented by Fig. (3), this may be effected by cutting in the inner
circumference of the coupling box (3) a fine screw thread g, which causes the weights
to revolve on their respective axes as long as the friction lasts, so that every time the
Price 871

page_text: coupling is set in gear, a different part of the circumference of the roller weights is
made to act on the box (3).
According to the method represented by Fig. (4) and (5), strips or plates (13) of
suitable material, one for each weight, are interposed between the weights and the
inner circumference of the coupling boxes, the said strips or plates being secured to
the coupling box (2) either by means of balancing pivots or trunnions (11), as shown
by Fig. (4), or by means of spring arms and screws (12), as shown by Fig. (5).
When the sleeve (6), together with the wheel or ring (5), is shifted to the left, the
weights roll from the position represented by dotted lines into the position
represented by full lines, and press the strips (13) against the inner circumference
of the coupling box (3).
When the wheel (5) is withdrawn, the weights roll again into the position
represented by dotted lines. Sliding friction takes place only or principally between
the strips (13) and the coupling box (3), which strips can be easily removed, while the
rollers are almost free from wear.
As in the case of other friction couplings, the driven part viz. the box (3), need
not be fixed on a separate shaft, which is to be set in motion, but may transmit motion
from its circumference in any convenient manner, or the arrangement may be
reversed, by making the shaft (1) the driven shaft and the shaft (15) the driving
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. In friction couplings adapted to operate by means of centrifugal force, the
combination of a coupling box open on one side, with a ring having in its
circumference open cells containing roller weights, and means for shifting the said
ring into and out of the said coupling box, the said ring being attached to the
driving part and the coupling box to the driven part, or vice versa, substantially as
described.
2. In centrifugal friction couplings of the type specified, a coupling box provided
at its inner circumference with a screw thread, in order to turn the roller weights on
their respective axes, substantially as described.
3. In centrifugal friction couplings of the type specified, the combination of. the
coupling boxes and roller weights with intermediate plates or strips secured to one
of the coupling boxes by means of pivots or springs, substantially as described.
4. A centrifugal friction coupling constructed and adapted to operate substantially
as described and illustrated by the drawings.
Dated this 5th day of August 1898
FAIRFAX & WETTER,
Agents, 37 and 39, Essex Street, Strand, London.
FAIRFAX & WETTER,
Agents, 37 and 39, Essex Street, Strand, London.