AN IMPROVEMENT IN THE RING ARMATURES OF CERTAIN DYNAMO-ELECTRIC OR ELECTRO-DYNAMIC MACHINES
Year: 1884

page_text: I; ROBERT EDWARD DUNSTON of Malden Factories, Kentish Town in the County
of Middlesex, Civil Engineer, do hereby declare the nature of my' Invention for
"AN IMPROVEMENT IN THE RING ARMATURES OF CERTAIN DYNAMO-ELECTRIC OR
ELECTRO-DYNAMIC MACHINES" and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :--
In ring armatures of the Pacinotti or Gramme kind used in certain dynamo
electric or electro dynamic machines, as the wire coils have approximately parallel
sides, the spaces between them on each side of the ring are necessarily wedge
shaped as illustrated in Fig. 1 of the accompanying Drawings shewing a side view
of part of the ring c having on it parallel sided coils e, with wedge shaped pieces a
filling the spaces between the coils. Sometimes these spaces aro filled up with
wood or such like material; sometimes pegs of wood are passed through the ring
between the coils, and sometimes when the ring is built up of separate annular
concentric hoops, strips of iron or other metal are passed through between the
separate hoops so as to project at each side between the coils. In some cases the
ring has parallel sided chases or grooves cut in its sides and periphery to receive
the coils, leaving the solid metal standing out between them. My Invention
consists in fixing between the coils pieces of iron a, which may be either made in
solid pieces or built up of strips, so as to project a little beyond the external faces
of the coils e and therefore to pass very close to the field magnets, which are thus
made to exert more influence on the coils. The pieces a may be fixed in various
ways. As shown in Fig. 1, and in the transverse sections Figs. 2 and 3 and in the.
perspective view Fig. 4, they are either connected to or formed in one piece with
an annular strip b which may be put on in segments on the main ring c, and
secured in its place by the winding on of the coils e which enclose portions of it, or
by the screwing of the pieces a to the ring a as shewn in Fig. 3. The strip b may
be made in short lengths sunk into the periphery.of the ring c as shewn in Fig. 5,
and held in position by the coils wound between the wedge pieces a. Figs. 6 and 7
are sections of the ring c. Fig. 8 is a perspective view and Fig. 9 a plan of part of
it shewing how the wedge pieces a may be secured; somewhat in the manner of a
bayonet catch, by notching their limbs internally and by a longitudinal movement
along the ring c engaging these notches on studs d projecting from the sides of the
D.
с

page_text: ring. As shewn in Figs. 10 and 11, each wedge piece a is made with a groove b to
receive a wire binding it to the ring c. The wedge pieces a may be made of a
number of plates fixed together side by side by rivetting and held on the ring c by
studs d as shewn in Figs. 12 and 13.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I hereby declaro that
I make no claim to the use in ring armatures of cogs or saddle pieces made in one
with the ring nor to pegs or metal strips projecting from the sides of the ring
between the coils thereon, but what I claim is :
Attaching to a ring armature separate wedge shaped saddle pieces of iron i
substantially as and for the purposes herein set forth.