Improved Holder for Brushes of Electro-motors and Dynamo Machines.
Year: 1887

page_text: Date of Application, 17th Mar., 1887
Complete Left, 15th Dec., 1887
Complete Accepted, 10th Feb., 1888
PROVISIONAL SPECIFICATION.
Improved Holder for Brushes of Electro-motors and Dynamo
Machines.
I, MORITZ IMMISCH, of 119 Torriano Avenue, Camden Town, London, in the
County of Middlesex, Electrician, do hereby declare the nature of this invention to
to be as follows:-
The objects of the present invention are 1st. To ensure a perfect and certain contact
between the brushes and commutator of electro-motors and dynamo machines at the
exact point where desired in spite of any variation in the diameter of the commutator
due to wear of same, and notwithstanding any wear of the brushes; and 2nd. To
provide an efficient arrangement of brush holders for enabling electro-motors to be
reversed.
In carrying out the first object of my invention I provide a holder frame one ond
of which I pivot to the frame of the machine in a suitable bearing, in which it can be
fixed when it has been shifted to the required position. This holder frame is insulated
from its bearing in the frame of the machine and it extends over the commutator.
From each end (i.e. the pivotted end and the outer end) an arm projects outwards and
forms bearings to receive trunnions on the brush holder proper, through which holder
the brushes are passed (so that they are transverse to and in a line with the axis of the
trunnions), and secured by screws. By first setting the pivot of the holder frame
above referred to in the desired position in its bearing the brushes will rest on the
commutator at the required point (and such holder frame can be shifted so as to
always ensure this), when it must be firmly secured in the position to which it has
been shifted. A spring or springs is or are caused to bear towards the end of each
brush and the pressure of such spring or springs can be adjusted so as to regulate the
pressure of the brush on the commutator, and also to re-adjust same when any wear
occurs.
As the holder proper is free to turn on its trunnions carried by the holder frame, the
springs acting on same will give, and so any vibrations which may occur will be
taken up.
A similar holder is provided for each brush

page_text: In carrying out the second object of my invention I employ two positive and two
negative brush holders similar to those above described, and arrange the positive
holders on one side and the negative holders on the opposite side of the commutator.
One or the positive brushes is connected to one arm of a double armed lever pivotted
at its centre to a fixed point of the frame of the machine on one side of the
commutator, and the other positive brush is connected to the other arm of such lever,
so that the two brushes are situated one above and the other below the commutator,
the two holders being metallically connected together. The two negative brushes
are similarly carried by a second double armed lever pivotted on the other side of
the commutator, and are also metallically connected together.
A link connects the two levers and is provided with a projection to which a part in
the form of an anchor is pivotted and moves over a slide formed with a notch at each
extremity. The anchor forms the handle or push for reversing the brushes and when
one of its arms engages the notch at one end of the slide, one of the positive brushes
is in contact, say with the upper or top side of the commutator, and one of the negative
brushes with the under or lower side of the commutator.
When it is desired to reverse the motor force or pressure is applied to the anchor
piece which is first caused to turn on its pivot and disengage the arm which occupied
the notch at one end of the slide, the continued pressure will then cause the anchor to
move along the slide carrying the link connecting the two double armed levers with
it, until the other arm of the anchor engages the notch at the other end of the slide.
This movement of the link causes the double armed levers to rock on their central
supports in the same direction, thus simultaneously lifting the positive brush off the
top and the negative brush off the bottom of the commutator, and at the same time
bringing the other positive brush to bear on the bottom and the other negative brush
on the top of the commutator. When the anchor is engaged with either of the notches
in the slide the brushes are locked in the position to which they have been moved and
can only be shifted by first disengaging the anchor by causing it to turn on its pivot.
A spring is preferably caused to bear on the anchor in order to avoid its accidental
disengagement from the notch in the slide.
Dated this 17th day of Moh 1887

page_text: I, MORITZ IMMISCH, of 119 Torriano Avenue, Camden Town, London in the County
of Middlesex, Electrician, 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 objects of the present invention are 1st. To ensure a perfect and certain contact
between the brushes and commutator of electro-motors and dynamo machines, at the
exact point where desired, in spite of any variation in the diameter of the commutator
due to wear of same, and notwithstanding any wear of the brushes; and 2nd. To
provide an efficient arrangement of brush holders for enabling electro-motors to be
reversed.
My invention is illustrated in the accompanying drawing, in which :-
Fig. 1 is a side elevation partly in section, of my complete holder, embodying both
features of my invention.
Fig. 2 is a plan view of same, also partly in section.
Fig. 3 is a detached end view of one of the double armed levers pivotted to the frame
of the machine, and
Fig. 4 is a detached end view of the brush holder proper.
In carrying out the first object of my invention I provide a holder frame A, one
end of which is pivotted at B to the frame of the machine in a suitable bearing C, in
which it can be fixed after having been shifted to the required position. This holder
frame A is insulated from its bearing C in the frame of the machine (as shown at C¹),
and it extends over the commutator D in the direction of its width. From each end
of the frame A (i.e. the pivotted end B and the outer end B¹) an arm E projects
outwards and forms a bearing to receive one of the trunnions F provided on the
brush holder proper F, through which holder the brush G passes (through the
longitudinal axis of the trunnions) and is secured by screws H. By first setting the
pivot B of the holder frame A in the desired position in its bearing C, the brush G will
rest on the commutator D at the required point (and such holder frame can be shifted
so as to always ensure this), when it must be firmly secured in the position to which
it has been shifted, by means of the nut I. A spring or springs J is or are caused to
bear towards the end of each brush G, and the pressure of such spring or springs can
be adjusted so as to regulate the pressure of the brush on the commutator, and also to
re-adjust same when any wear occurs, the screws K' being provided for this purpose,
and working through an arm K secured to and projecting inwards from the holder
rame A.
As the holder proper F is free to turn on its trunnions F1 carried by the holder

page_text: frame A, the springs J acting on same will give, and so any vibrations which may
occur will be taken up.
A similar holder is provided for each brush.
In carrying out the second object of my invention I employ two positive brush
holders A, A, and two negative brush holders A2, A3, arranging the former on one
side and the latter on the opposite side of the commutator D.
The positive brush G is mounted on one arm of a double armed lever L, pivotted at
its centre M to a fixed point of the frame of the machine on one side of the
commutator D, and the other positive brush G¹ is mounted on the other arm of such
lever L, so that the two positive brushes G, G¹, are situated one above and the other
below the commutator D, the two holders A, A¹ being metallically connected together.
The two negative brushes G2, G3, are similarly carried by a second double armed
lever L' pivotted on the other side of the commutator D at M¹, and are also
metallically connected together.
A link Ň connects the two levers L, L', and is provided with a projection N, to
which a part O in the form of an anchor is pivotted at 1, and moves over a slide P
formed with a notch P1, P2, at each extremity. The anchor forms the handle or
push for reversing the brushes, and when its arm 01 engages the notch P¹ at one end
of the slide P (as shown in Fig. 1), the top positive brush G is in contact with the
upper or top side of the commutator D, and the negative brush G3 with the under or
lower side of same.
When it is desired to reverse the motor force or pressure is applied to the anchor
piece O, which is first caused to turn on its pivot R and disengage the arm O from
the notch P at one end of the slide P; the continued pressure will then cause the
anchor to move along the slide P, carrying the link N connecting the two double
armed levers L, L', with it, until the other arm 02 of the anchor engages the notch P²
at the other end of the slido P. This movement of the link N causes the double
armed levers L, L, to rock on their central supports M, M', in the same direction,
thus simultaneously lifting the positive brush G off the top and the negative brush G³ off
the bottom of the commutator, and at the same time bringing the other positive brush G¹
to bear on the bottom and the other negative brush G2 on the top of the commutator D.
When the anchor O is engaged with either of the notches P1, P2, in the slide P, all
the brushes are locked in the positions to which they have been moved, and can only
be shifted by first disengaging the anchor O by causing it to turn on its pivot R. A
spring S is preferably caused to bear on the anchor in order to avoid its accidental
disengagement from the notch in the slide.
The movement of the top brush holders proper on their trunnions in the direction
to move the brushes downwards towards the commutator, is limited by the under side
of the brush coming in contact with a stop or projection T on the under bar of the
holder frame A, so that the brush cannot fall by its weight on to the commutator,
when the lever L or L is in the position where the top brush it carries ought to be
out of contact.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what 1
claim is
1. The improved holder for commutator brushes consisting of a holder frame
pivotted to the frame of the machine (so that it can be adjusted and fixed thereon),
and provided with outwardly extending arms with bearings to receive trunnions with
which the brush holder proper is provided, all substantially as and for the purpose
specified.
2. The arrangement of holders for commutator brushes for the purpose of enabling
electro-motors to be reversed, such arrangement consisting in mounting two positive
brushes respectively at opposite ends of a double armed lever, which is pivotted at its
centre to the frame of the machine, so that one brush occupies a position above and
the other below the commutator on one side of the vertical axis thereof, while two

page_text: negative brushes are similarly mounted and disposed on the other side of such vertical
axis, the two double armed levers being connected so as to move simultaneously in
the same direction on their pivots, the whole constructed and operating substantially
as specified.
3. The means for actuating and locking the double armed lovers referred to in the
preceding claim, consisting in the pivotted anchor piece O working over a slide
provided with notches at its opposite ends, with which notches the opposite arms of
such anchor piece respectively engage, when the latter is at the limit of its travel in
either direction, substantially as specified.
ALLISON BROS.,
Agents for the Applicant.