IMPROVEMENTS IN FRICTION GEARING
Year: 1876

page_text: LETTERS PATENT to Ernst Brauer, of Berlin, Prussia, for the Invention of
"6
IMPROVEMENTS IN FRICTION GEARING."
PROVISIONAL SPECIFICATION left by the said Ernst Brauer at the Office
of the Commissioners of Patents on the 9th November 1876.
66
ERNST BRAUER, of Berlin, Prussia. IMPROVEMENTS IN FRICTION GEARING."
According to this Invention I make friction pulleys or wheels with a number of
flat rings, by preference of hoop iron, which can shift or swing in their axial
direction on their pulleys or wheels, but by a fixed spring appliance are prevented
from turning against the same. The rings of two such wheels gear into one another
alternately at the place of contact, that is like fingers of two hands interposed
between one another, so that a pressure exerted there in a direction vertical to the
wheels is transferred with equal intensity through all points of contact successively
up to the resistance on the opposite side, and thereby produces a friction which is
available for mutual movement, this friction being equal to the friction between
two such multiplied by the number of points of contact.
In order to prevent the hoops from assuming a slanting position to each other
because of the pressure I provide a pressing disc, the nave of which is bored out
true and can slide on the shaft of one of the wheels; the flanged edge of this
pressing disc can be made to bear against the end hoop of the wheel or pulley.
The shaking and clatter of the hoops is prevented by means of interposed rings of
felt or other suitable yielding material placed on a wire or rod passed through thein
and fixed to the pulley rim in, say, three or more places. The felt rings may
however be left out if preferred.
In order to prevent objectionable friction I preferably reduce the surface-of
contact as much as possible to a point, and for this purpose the hoops on one
pulley or wheel are formed conical and the hoops on the other parallel.
As the number of such friction wheel pairs may be as large as desired it is
obvious that the pressure between each pair may be as small as desired for
preventing great wear and tear; also that such friction wheels may be used for the

page_text: transmission of far greater power than any heretofore known friction wheels. To
clutch out these wheels it is only necessary to remove the pressure of one against
the other, which may be done by any well known clutch appliance also during the
working of the wheels. A sleeve which by a fixed rod is prevented from turning
on the friction wheel shaft may for this purpose be fitted thereto and formed with a
flange, and abutting axially against a flange or ring fixed or formed on the shaft ;
another sleeve may by the turning of a hand wheel formed with a female thread
draw the latter sleeve one way or the other, thereby compressing or releasing india-
rubber washers interposed between the sleeve and the aforesaid ring, which serves
to press the end hoop of one friction wheel against the corresponding one of the
other friction wheel.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Ernst Brauer in the Great Seal Patent Office on the 8th May 1877.
ERNST BRAUER, of Berlin, Prussia. "IMPROVEMENTS IN FRICTION GEARING."
According to this Invention I make friction pulleys or wheels with a number of
flat rings, by preference of hoop iron, which can shift or swing in their axial
direction on their pulleys or wheels, but by feather and groove or other fixing
appliance are made to turn round with the wheel, and rings of two such wheels
gear into one another alternately at the place of contact, that is like fingers of two
hands interposed between one another, so that a pressure exerted there in a direction
vertical to the wheels is transferred with equal intensity through all points of
contact successively up to the resistance on the opposite side where the last hoop
rests against a projecting flange, and thereby produces a friction which is available
for mutual movement, this friction being equal to the friction between two such
multiplied by the number of points of contact.
Figure 1 of the accompanying Drawings is a section through three such pulleys
or wheels A, B, and C, gearing with one another; Figure 2 is an enlarged section of
the rim part of same showing the place of contact between them; and Figure 3 is an
end elevation. The two wheels A and B are provided with hoop iron rings h and k
respectively.
In order to prevent the hoops from assuming a slanting position to each other
because of the pressure, I provide a pressing disc a, the nave of which is bored out
true and can slide on the shaft of one of the wheels, or as in this case on the shaft
and nave of the wheel B. The flanged edge of this pressing disc a can be made to
bear against the end hoop of the wheel or pulley B. The shaking and clatter of the
hoops is prevented by means of interposed rings b of felt or other suitable yielding
material placed on a wire or rod and m respectively passed through them and
fixed to the pulley rim in, say, three or more places; o, o, shown in elevation at
Figure 4, are lugs for holding the wires. The felt rings may however be left out if
preferred.
In order to prevent objectionable friction I preferably reduce the surface of
contact as much as possible to a point, and for this purpose the hoops on one pulley
or wheel; in this case the smallest one B are formed conical and the hoops on the
other parallel, as shown.
The
As the number of such friction wheel pairs (each driving and driven hoop con-
stituting, so to say, a wheel pair) may be as large or small as desired, it is
obvious that the pressure between each pair may be as small or large as desired for
preventing great wear and tear; also that such friction wheels may be used for the
transmission of far greater power than any heretofore known friction wheels.
hoops on the pinion spindle C are similar to those described. To clutch out these
wheels it is only necessary to remove the pressure of one against the other, which
may be done by any well known clutch appliance, also during the working of the
wheels. A sleeve which by a fixed rod is prevented from turning on a shaft of one

page_text: friction wheel may for this purpose be fitted thereto and formed with a flange, and
abutting axially against a flange or ring fixed or formed on the shaft; another
sleeve may by the turning of a hand wheel formed with a female thread draw the
latter sleeve one way or the other, thereby compressing or releasing india-rubber
washers interposed between the sleeve and the aforesaid ring which serves to press
the end hoop of one friction wheel against the corresponding one of the other
friction wheel. A suitable appliance for this purpose is shown here at Figure 1.
The sleeve c is by the rod & prevented from turning round with the shaft of the
wheel B; the presser sleeve e can be pushed endways relatively to the sleeve c by
means of a hand wheelf forming the nut to the male screw thread on the sleeve e,
and abutting against the sleeve c, which again abuts against the collar n fixed on
the shaft, the presser sleeve e can thereby be made to press against india-rubber
washers g, and against the ring a which presses against the hoops k. To clutch out
run the hand wheel ƒ back again, and the ring a will be released and the frictional
pressure of the hoops k and h against one another will thereby be removed. This
wheelf may obviously also serve to regulate the frictional pressure as required.
A certain similarity will be observable between the aforesaid friction wheels and
those of three other inventors, and I will now proceed shortly to notice them,-
1. Sellars, of Philadelphia, uses in turning lathes friction wheels, in which lateral
pressure is applied for transmission of power, but only for one pair of hoops; hence
for small power only and without using means for preventing the hoops from
assuming a slanting position.
2. Minotte has in his wedge wheels attempted the same object as here described,
vis., to distribute the pressure over many points of contact, and thus to diminish
the wear; but the great difficulties of manufacture of his appliances have left the
object very far from being attained.
3. In the disc coupling which comes more and more into use the principle is is also
applied of changing the friction according to the number of points of contact by the
alternate gearing of the discs connected with the two halves of the coupling.
Now according to this Invention all these three ideas are combined in such a
way as to produce a novel means for transmission of power possessing the following
important advantages:
1. Perfectly noiseless working, even with the highest number of revolutions.
2. The facility afforded for the greater differences in diameter of the wheels, as
the latter may conveniently be made very small and work well with very large
wheels in contradistinction to ordinary tooth wheels and strap pulleys, where a great
disparity in size is inadmissible.
3. The possibility of gliding of the hoop surfaces against one another in case of
extra strain, thus preventing breakage of the machinery.
4. Small loss of effect through friction."
5. Facility for throwing out of gear.
6. Facility for adjusting the pressure to the exact requirements.
7. Saving in material, because the wheels and parts connected are not exposed to
shocks as ordinary tooth wheels sometimes are, and may therefore be made lighter.
8. Small wear and tear, as the surface pressure is small and lubrication may be
applied.
9. Complete absence of the strong axial pressure which takes place in most
other friction wheels.
Because of the two first points these wheels are suitable for lathes, centrifugal
pumps, blowing fans, extractors, wood working machines, and for all transmissions
to very great speed from a comparatively slow speed, and vice versa; because of the
second point their applicability to winches is obvious, because one pair of wheels
will-suffice.
The third point is of importance in regard of such machines wherein great
irregularities take place, such as rock drills, plate shearing machines, punching
machines, horse gear, and rolling mills of the most different kinds; applied to
cranes and winches the wheels will prevent dangerous overloading of same.

page_text: The fourth. point recommends their application where power is to be saved, and
affords especially a guarantee against stoppage of works, as the coupling and
uncoupling can be effected during the working of the gear.
The points 6, 7, 8, and 9 need no special elucidation. Respecting wear and tear
it may be mentioned that the results obtained are from wheels applied to a
threshing machine and beater drum with 830 revolutions per minute. The hoops
may while in motion be faced up if required after some years wear.
From the foregoing it will be clear that these wheels are applicable almost in all
cases in preference to tooth wheel gearing, except in such where a very exact speed
proportion is to be maintained very often; also in preference to strap and. pulleys;
the costs are not higher and for large dimensions even lower than those of tooth
wheels. As applied to cranes and winches these friction wheels may be and have
already been used by the inventor for the purposes to which brake wheels and pawl
wheels are now applied.
And having thus fully described the nature of this my Invention, I declare that
I claim,-
Firstly. The application of hoops to the circumferential faces of wheels so as to
be able to slide but not turn thereon, the hoops of one wheel fitting in the spaces
between the hoops of the other wheel, and being evenly pressed against one another
for effecting frictional power transmission, all substantially as set forth.
Secondly. The application to friction hoops as set forth of felt or other inter-
mediate packing rings or pieces, held together and operating substantially as
set forth.
Thirdly. The mode and means here set forth for producing, regulating, reducing,
or taking off the pressure wherewith the hoops of one wheel are held against those
of the other wheel.
In witness whereof, I, the said Ernst Brauer, have hereunto set my hand
and seal, this Fifth day of May, in the year of our Lord One thousand eight
hundred and seventy-seven.