Improvements in Electric Signals or Indicators.
Year: 1899

page_text: Date of Application, 27th Apr., 1899-Accepted, 27th May, 1899
Improvements in Electric Signals or Indicators.
We, ALWYN WALTER STAVELEY, of East View, Regent Road, and ISAAC HARDY
PARSONS, of "Branscombe," Hinckley Road, both of Leicester, in the County of
Leicester, Electricians, 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 what are known as drop signals, or indicators, especially
those known as clutch drop " movements, and those movements where the
electro-magnet employed is formed by a horse-shoe, or "U" shaped core, and has
for its object the simplifying and cheapening of the construction of such indicators,
notably in three directions.
1. Whereas indicators having their magnetic cores horse-shoe shaped, and their
ends driven into a metallic plate or frame, which supports other mechanism, namely
the armature catch and the signal arm, hitherto have had this plate constructed
of some non-magnetic metal, such as brass, to avoid such plate completing the
magnetic circuit, our invention enables us, by clipping a piece of non-magnetic
material between the plate, to use for the plate itself a magnetic metal, notably sheet
iron (which is cheaper and better,) and at the same time fix the horse-shoe magnet
firmly and rigidly by both poles or ends.
2. Heretofore the armatures of clutch drop indicators have been made from cast
metal, the weight being distributed so that they over-balance in the required way,
or if stampings from sheet metal have been used, they have been controlled by a
spring. Our invention enables us to over-balance a sheet metal armature in the
manner described, by doubling over certain extension pieces in such a way as to
make several thicknesses of metal where weight is required, and one, or fewer
thicknesses of metal where it is required that the armature should be lighter.
3. Further, in clutch drop indicators, the signal arm, or lever, with its sleeve, or
bearing, carrying the signal disc, has heretofore been made from cast metal, or
of stampings and turnings riveted together-in our invention we form the said
arm and its bearings, by stamping out a tongue from the centre of a piece of
sheet metal of suitable size and shape, and so bending and piercing the metal as
to form two bearings to work on a screw, or pivot.
To enable our invention to be more fully understood, we describe the same by
reference to accompanying drawing, where
Fig. is the elevation of a complete clutch drop movement.
Fig is a side elevation of same.
Fig is a plan of same.
Figs. 4, 5, and 6 are views showing methods of clipping a non-magnetic metal to
the iron plate.
Figs. & 8 illustrate the improved armature stamping.
Figs. 9 & 10 illustrate the improved signal arm.
a is the base from which is bent
the piece b. c is an embossed non-magnetic
metal plate, having a circular hole at one end, which admits easily, but without
shake, one end f of the horse-shoe shaped magnet core. D is a slot cut in the plate c

page_text: and is in such a position, and of such a size, that when slipped over the projecting
piece b in plate a, the projection can be closed down, and will thus clip the plate c,
holding it firmly and rigidly, the side flanges on c preventing any lateral movement.
e is a hole punched through the folded up projecting part b, and through c, which is
folded up in b, and is of such a size that the end of the magnet f will drive in tight,
and remain rigid.
Fig. 4 shows details of bent piece b, whilst Figs. 5 and 6 are elevation and plan
of the extension piece c.
Fig. 2 shows clearly how is firmly clipped, and how the magnet poles f and f¹
are held in position.
Fig. 7 shows the blank from which the improved armature is made. The
parts m and m' are bent at right angles to form bearings for a pivot or screw,
whilst the part is doubled over, and the part is doubled over n.
right angles to form the catch on the armature.
Fig. 8 is an elevation of the armature.
g is bent at
The
Fig. 9 shows blank from which we manufacture the improved signal arm.
piece r, shown by dotted lines, is knocked out to form a tongue, and bent at right
angles from the point s, and at point t the tongue is again bent at right angles
holes being pierced at points kk, which form the bearings to work on the screw or
pivot, as shown at Fig. 10.
With the arrangement hereinbefore described, it will be readily seen that if,
when the signal disc is in the position shown in full lines in Fig. 1, an electric
current is passed round coil of the electro-magnet, the armature w will be operated
to disengage the catch on the signal arm-whereby the signal disc will drop to
position indicated by the dotted lines in Fig. 1, and the disc will be returned to its
normal position by pushing the arm z.
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. In electric indicators the use of a non-magnetic extension piece, clipped or
riveted to an iron plate, and forming holes to receive the poles of an electro-magnet
in the manner described.
2. In an electric indicator the manufacture and use of a stamped iron armature,
balanced or weighted by pieces of iron left on the blank being doubled over in
the manner described.
3. In an electric indicator the manufacture and use of a metal arm, struck out of
sheet metal, and bent in the manner described.
4. In an electric indicator the bending and folding of sheet metal as, and for
the purposes described.
Dated the 26th day of April 1899.
ALWYN WALTER STAVELEY.
ISAAC HARDY PARSONS.