Improvements in Dynamo Electric Machines.
Year: 1895

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Complete Specification Left. 28th Sept., 1896-Accepted, 7th Nov., 1896
PROVISIONAL SPECIFICATION.
Improvements in Dynamo Electric Machines.
We, P. R. JACKSON & Co. LTD. Steel Manufacturers, and JOSEPH
SLATER LEWIS, Engineer, both of Salford Rolling Mills, Hampson Street,
Salford, in the County of Lancaster, do hereby declare the nature of this invention
to be as follows:-
Our invention relates to dynamo electric machines of the type known as the
"under" or "Edison" type and has for its object to improve and cheapen the
construction of the field magnets of such machines. Our invention also comprises
an improved construction of bobbin for the field magnet coils of these machines.
According to our invention the field magnet cores and yoke, and sometimes the
pole pieces also, are formed in one piece being preferably made in one steel casting.
The pole pieces are secured to the cores by short bolts or set pins screwed in to
the cores through a flange of the pole piece formed by undercutting a portion of
the same adjacent to the junction thereof with the core. When the pole pieces are
cast in one with the cores they are first sawn from them or parted by suitable
means. The metal sole-plate joining the ends of the pole-pieces and which carries
them and their adjuncts is preferably made of gun-metal and is secured thereto by
set pins. By this construction either one of the pole pieces can be very readily moved
out laterally when the bolts holding it in place are removed, thus exhibiting the
armature. The upper part of the field magnet requires supporting to a small
extent when the pole piece is finally withdrawn.
In order to prevent the magnet coils slipping off the cores when the pole-piece is
removed we provide a projecting strap of metal or other material secured to or
forming part of the bobbin. This is secured to the yoke of the magnet in any
suitable manner.
For example the said tongue may project through a hole or slot
made in a flange on the yoke and may be secured by means of a nut or other
suitable means.
This construction also enables us to draw the field magnet coils
up into position, where they remain suspended independently altogether of the
projecting flange on the pole-piece, which is usually employed for this purpose.
Dated this 28th day of December 1895.
W. P. THOMPSON & Co.,
31, High Holborn, London, W.C., Patent Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Dynamo Electric Machines.
We, P. R. JACKSON & Co. LTD. Steel Manufacturers, and JOSEPH
SLATER LEWIS, Engineer, both of Salford Rolling Mills, Hampson Street,
Salford, in the County of Lancaster, 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 :---
Our invention relates to dynamo electric machines of the type known as the
"under "
or Edison type and has for its object to improve and cheapen the
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011
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page_text: construction of the field magnets of such machines. Our invention also comprises
an improved construction of bobbin for the field magnet coils of these machines.
According to our invention the field magnet cores and yoke, and sometimes the
pole pieces also, are formed in one piece being preferably made in one steel casting.
The pole pieces are secured to the cores by short bolts or set pins screwed into
the cores through a flange of the pole piece formed by undercutting a portion
of the same adjacent to the junction thereof with the core. When the pole pieces
are cast in one with the cores they are first sawn from them or parted by suitable
The metal sole-plate joining the ends of the pole-pieces and which carries
them and their adjuncts is preferably made of gun metal and is secured thereto
by set pins.
means.
In order that our invention may be clearly understood we have illustrated in
the accompanying drawing a dynamo electric machine of our improved construction.
Figure 1 is a front elevation and
Figure 2 is a side elevation partly sectional of the machine.
A, A, are the pole-pieces, B the yoke, C the sole-plate and D the magnet coils.
The pole-pieces are undercut or recessed as shewn at A' and through the flange so
formed are screwed bolts A' by means of which the pole-pieces are connected to
the field magnet cores. The bolts connecting the sole-plate to the pole-pieces are
shewn at C said bolts are screwed up or unscrewed when necessary through
orifices C2 in the side of the sole plate opposite the bolt heads.
By this construction either one of the pole pieces can be very readily moved out
laterally when the bolts holding it in place are removed or the pole piece may be
moved out a short distance and then slewed round so as to permit inspection or
cleaning of the armature without removing the pole piece entirely. When the
pole piece is wholly withdrawn the upper part of the field magnet requires
supporting to a small extent.
In order to prevent the magnet coils slipping off the cores when the pole piece
is removed we provide a projecting strap of metal or other material secured to or
forming part of the bobbin. This is secured to the yoke of the magnet. in any
suitable manuer.
For example as shewn in the drawing the strap E projects
through a hole or slot made in the flange B¹ on the yoke B and is secured by
means of a nut E' turning in a recess in the yoke. This enables us to draw the
field magnet coils up into position. The strap may also be flat and be secured to
the yoke by a bolt screwed horizontally thereinto through an orifice in the strap.
By this device the coils are, suspended independently altogether of the projecting
flange on the pole piece, which is usually employed for this purpose.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
1. A dynamo electric machine constructed as described with reference to the
accompanying drawing.
2. For a field magnet coil a bobbin provided with a projecting strap and means
for securing said strap to the yoke substantially as described.
Dated this 28th day of September.
W. P. THOMPSON & Co.,
322 High Holborn, London, W.C., Patent Agents for the Applicants.