IMPROVEMENTS IN COUPLINGS FOR SHAFTS WHEELS AND THE LIKE
Year: 1885

page_text: We MAX LOHMANN and MAX STOLTERFOHT doing business under the firm of
Lohmann & Stolterfoht at Berlin W. Lutzow str 99 do hereby declare the nature
of the said invention for "IMPROVEMENTS IN COUPLINGS FOR SHAFTS WHEELS AND
THE LIKE" to be as follows :—
The characteristic feature of the friction coupling to which this invention relates
is, that the body or part (say a belt or rope pulley, or a friction wheel or toothed
gear) which is to be connected with a continuously rotating shaft is when it is to
be disconnected, so shifted in the direction of its axis that all contact between the
friction surfaces ceases and that the part which is to be intermittently rotated is
totally disconnected from the continuously rotating portions, By this means
excessive wear of the bore of the part to be intermittently rotated is avoided as
well as loss of power. Moreover the non-rotating parts of the clutch gear may be
so arranged that when the coupling is released, they act as a brake for the dis-
connected part and thus the uncoupled parts of machinery will soon be stopped
and an accidental restarting of the same, which might prove a source of danger is
avoided.
The coupling is furthermore combined with elastic connecting or intermediary
parts in a well known manner so that in uncoupling these elastic resilient parts
are compressed whilst when the parts are coupled up their elasticity produces the
required amount of friction.
Upon the driving shaft a coupling piece is fixed; in one form it may have plain
straight and conical friction-surfaces. To these surfaces correspond the conical
bore of the boss or nave of the part which is to be rotated (say a pulley) and the
contiguous surface of a disc. With the boss a second disc is firmly connected by
bolts whilst bolts connect the discs. As the bolts pass through holes or recesses of
the discs and through flanges of the boss or nave, it follows that the parts can be
moved relatively to one another in the direction of their axes but can not rotate
independently of one another. The exterior discs will therefore be compelled
always to participate in the rotation of the rotating part.
Between either the one or the other pair of disc surfaces an elastic body is
inserted, say a ring of india rubber or a spring which tends to move the parts
apart axially so that the friction surfaces come into contact with one another.
The exterior discs are carried upon cylindrical bearing surfaces by sleeves which

page_text: slide upon the shaft. The shifting of the sleeves is effected by means of pivoted
levers and having their upper ends adjustable by a nut and screw arrangement.
The sleeves may conveniently be utilized as bearings for the shaft also and for this
purpose have bearing surfaces; as the levers have a very limited motion only the
sleeves may be considered as guided in a straight line. By reason of this arrange-
ment the discs and the rotary parts are, when the coupling is thrown out of gear,
carried entirely by the sleeves and by means of the surfaces so that a slight
amount of motion between the sleeves suffices for removing the friction surfaces
from the corresponding surfaces and to maintain the rotating part freely suspended
without allowing the flexibility of the shaft to act disadvantageously. The bearing
surfaces ensure that the movement between the parts may take place in a suitable
manner. These surfaces also prevent any injurious contact between the friction
surfaces after they are thrown out of gear.
As moreover the rotation of the sleeves is prevented the surfaces serve as brake
surfaces also and tend to retard the motion of the rotating part when the coupling
is thrown out of gear.
Screws allow the pressure exerted by the elastic body to be regulated.
The coupling can be modified in several ways the essential portions above
referred to being always retained; thus in one form both the friction surfaces are
cone shaped and the disc forms the nave of one half of the rotating body the
bearing surfaces are replaced by conical surfaces and two elastic rings are provided.
The elastic pressure of the parts is in this form and in similar ones regulated by
screws. In a modification of this coupling the discs are entirely omitted and the
parts are directly filled with bearing surfaces. The coupling piece fixed upon the
shaft here consists of two parts adjustably connected by screws. One part has a
conical friction surface and plain bearing surface, whilst the other part has a
straight friction surface and a straight bearing surface. The teeth rising from the
nave or boss and engaging with suitable recesses in the adjoining part of the
mechanism prevent rotation of the parts relatively to one another.
Here also the screws allow the elastic pressure of the ring to be regulated.
Both friction surfaces may be conical, both parts are part of the rotating body
and directly provided with conical bearing surfaces.
The teeth of a toothed wheel engaging with the rotary part of the mechanism
prevent undue rotation of the other parts. The sleeves may have independent
bearings so that they do not touch the shaft which has also independent bearings
so that the surfaces are entirely dispensed with. Here also contact surfaces are
provided.
Generally speaking the parts, when the coupling is disengaged, are shifted only
to such an extent, that the contact surfaces just touch, unless it is intended to
produce a brake-like action upon the shaft.

page_text: Improvements in Couplings for snarts, wheels, and the uke.
We MAX LOHMANN and MAX STOLTERFOHT doing business under the firm of
Lohmann and Stolterfoht at Berlin W., Lutzow Strasse 99 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:-
The characteristic feature of the friction coupling to which this invention relates
is, that the body or part: (say a belt or rope pulley, or a friction wheel or toothed
gear) which is to be connected with a continuously rotating shaft is, when it is to
be disconnected, so shifted in the direction of its axis that all contact between the
friction surfaces ceases and that the part which is to be intermittently rotated is
totally disconnected from the continuously rotating parts. By this means excessive
wear of the bore of the part to be intermittently rotated is avoided as well as loss
of power. Moreover the non-rotating parts of the clutch gear may be so arranged
that when the coupling is released, they act as a brake for the disconnected part
and thus the uncoupled parts of machinery will soon be stopped and an accidental
restarting of the same, which might prove a source of danger is avoided.
The coupling is furthermore combined with elastic connecting or intermediary
parts in a well known manner so that in uncoupling these elastic resilient parts
are compressed, whilst when the parts are coupled up their elasticity produces the
required amount of friction.
In the accompanying drawings several forms of this coupling are shown.
Figure 1 shows in elevation; partly in section a geared coupling.
Figure 2 is a transverse section of the same.
Figure 1 shows the parts of the coupling when disengaged or conclutched.
Upon the driving shaft W a coupling piece a is fixed; in this form it is represented
as having plain straight and conical friction surfaces 8. To these surfaces corre-
spond the conical bore of the boss or nave b of the part v which is to be rotated
(here shewn as a pulley) and the left hand surface of the disc c. With the boss b
a second disc b¹ is firmly connected by bolts t, whilst bolts S connect disc c with
disc c'. As the bolts t pass through holes or recesses of the disc c and the bolts S
through the flanges of the boss or nave b it follows that the parts b b and c c¹ can
be moved relatively to one another in the direction of their axes but cannot rotate
independently of one another.
The exterior discs b¹ c' will therefore be compelled always to participate in the
rotation of the rotating part v.
Between b and c or band o¹ or as represented between c and 61 an elastic body e
is inserted, say a ring of indiarubber or a spring which tends to move the parts b bi
and c c axially apart, so that the friction surfaces of come into contact with one
another, see Figure 1. The exterior discs b¹ and c¹ are carried upon cylindrical
bearing surfaces B by sleeves g and h which slide upon the shaft W. The shifting
of the sleeves is effected by means of levers p pivotted in o and having their upper

page_text: ends adjustable by a. nut and screw arrangement. The sleeves g and h
may
conveniently be utilised as bearings for the shaft W and for this purpose have
bearing surfaces ; as the lever p have a very limited motion only the sleeves g
and may be considered as guided in a straight line. By reason of this arrange-
ment the parts bc, b₁ c¹ and v are when the coupling is thrown out of gear, carried
entirely by the sleeves g and h and by means of the surfaces ẞ so that a slight
amount of motion between the sleeves g and h suffices for removing the friction
surfaces from the corresponding surfaces on the parts b and c and to maintain
the rotating part freely suspended without allowing the flexibility of the shaft to
act disadvantageously. The bearing surfaces a between g and bi and h and c¹ on
the one hand and between c¹ and a on the other ensure that the movement between b
c c¹ and a may take place in a suitable manner.
These surfaces also prevent any. injurious contact with the friction surfaces f
after they are thrown out of gear; the flat surface on the left has a similar effect.
As moreover rotation of the sleeves g and his prevented, the surfaces a and B
serve as brake surfaces also and tend to retard the motion of the rotating part v
when the coupling is thrown out of gear. The screws t allow the pressure exerted
by the elastic body e to be regulated.
Figure 4 shows the general arrangement of a shaft fitted with such couplings.
As illustrated by Figures 3, 5, and 6 the coupling can be modified in several ways
the essential portions above referred to being always retained, thus in Figure 3
both the friction surfaces fare conical shaped and the disc c forms the nave of one
half of the rotating body v; the bearing surfaces a and B are replaced by conical
surfaces and two elastic rings e are arranged between 6 and c¹ and between c
and b. Figure 3 shows the coupling out of gear. In this form also the bearing
surfaces ensure correct axial motion of the parts whilst the surfaces y act as
brakes during the uncoupling of the gear.
The elastic pressure of the parts is regulated by the screws t as well as the
screws 8.
In the modification of this coupling as shown in Figure 5 the discs b' and c¹ are
entirely omitted and the parts b and c are directly fitted with bearing surfaces a
and B. The coupling piece fixed on the shaft here consists of two parts a and a¹
adjustably connected by screws t; the part a has a conical friction surface f and
plain bearing surface, whilst a¹ has a straight friction surface f and straight
bearing surface . The teeth i rising from the nave or boss b and engaging with
suitable recesses on c prevent rotation of b relatively to c.
Here also the screws t allow the pressure of the elastic body e to be regulated.
In Figure 6, both friction surfaces f are shown as conical both parts b and c are
part of the rotating body v and directly provided with conical bearing surfaces y.
The teeth of a toothed wheel engaging with the rotary part v prevent rotation
of the parts b and c relatively to one another. As will be seen in Figure 6 the
sleeves g and h may have independent bearings so that they do not touch the
shaft W which has also independent bearings so that the surfaces & are entirely
dispensed with. Here also contact surfaces are provided.!
Generally speaking the parts when the coupling is disengaged are shifted only
to such an extent, that the contact surfaces just touch each other unless it is
intended to produce a brake like action upon the shaft W.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we de lare that what
we claim is:-
1. A friction coupling for connecting or disconnecting a rotary body with a
shaft consisting of the parts such as a, b, c, h and g movable relatively to each
other and provided with the friction surfaces f and the bearing surfaces a ẞ and y
respectively and an elastic intermediate body e the whole constructed and operating
substantially as specified.
.

page_text: 2. The co-axial disposition of the sleeves g and h with the shaft W the arrange-
ment of bearing surfaces & upon these sleeves forming a bearing for the shaft for
the purpose of preventing the contact of the conical surfaces f after the disconnecting
of the coupling substantially as specified.
3. The bearing surfaces on part a to prevent contact of the conical surfaces
after disconnecting the coupling substantially as specified.