Improvements in Electric Clutches.
Year: 1890

page_text: Date of Application. 14th Oct., 1890
Complete Specification Left, 13th July, 1891-Accepted, 15th Aug., 1891
PROVISIONAL SPECIFICATION,
Improvements in Electric Clutches.
I, PETER WILLIAM WILLANS of Ferry Works, Thames Ditton, in the County
of Surrey, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention has for its object improvements in electric clutches.
In order to connect two shafts in line with each other, one the driving and the
other the driven shaft I fix upon the one an iron cross head or magnet core with
projecting extremities and upon the other an iron wheel or ring. There are internal
projections upon the ring on either side and the arrangement is such that the
extremities of the first mentioned part come into close proximity to the projection
on the interior of the ring. One of the parts is wound with coils through which an
electric current may be passed in this way one part is magnetised and the other
part completes the magnetic circuit. The extremities and projections may be so
fashioned as to present a series of poles with intervals between them.
In this clutch the parts do not come into actual contact but operate by the
magnetic drag.
Improvements in Electric Clutches.
1, PETER WILLIAM WILLANS, of Ferry Works, Thames Ditton, in the County
of Surrey, Engineer, 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 -
This invention has for its object improvements in electric clutches.
In order to connect two shafts in line with each other, one the driving and the
other the driven shaft fix upon the one an iron cross head or magnet core with
projecting extremities and upon the other an iron wheel or ring. There are internal
projections upon the ring and the arrangement is such that the extremities of the
first mentioned part come into close proximity to the projection on the interior of
the ring. One of the parts is wound with coils through which an electric current
may be passed in this way one part is magnetised and the other part completes
the magnetic circuit. The extremities and projections may be so fashioned as to
present a series of poles with intervals between them.
In this clutch the parts do not come into actual contact but operate by the
magnetic drag.
In order that my said invention may be fully understood and readily carried inte
effect I will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 shows the electric clutch in a simple form, and in part diagrammatically.
a is an iron bar fixed to and projecting radially from one of the axes to be coupled.
bis this axis. ccare insulated wire windings upon the bar a through which the
circuit of a battery or other source may be completed at pleasure, whereby the bar a
is magnetised. The circuit is made to pass through brushes and insulated rings on

page_text: the axis in a well known manner. d is a disc fixed upon the second axis, it has a
ring like flange d' and this is notched to form upon it a succession of horns d*.
When one of the parts a, d, revolves without the other, eddy currents are
generated, and resistance is offered to such independent rotation. To favour this
action rings of metal of low electrical resistance such as copper may be fixed around
the horns.
Figure 2 is similar to Figure except that the bar a is provided with several
horns a corresponding to the horns d upon the ring d¹.
Figure 3 shows a longitudinal section of another form of electric clutch. The
bar upon the axis in this case becomes a complete disc and the winding is in a
groove around its periphery. On either side of the groove are horns a*. The
disc d also has horns * as in Figures 1 and 2 but in this case there are two circles
of horns in place of one only. is the axis on which the disc d is fixed, it may
be either the driving or the driven axis.
In this figure the insulated rings for receiving the current and conveying it to
the winding are shown.
Figure 3 is a part end elevation of Figure 3..
Figure 4 shews an arrangement similar to Figure 3 but the disc d has one ring
of horns only and these enter between the horns upon the disc a.
Figure 5 is a part end elevation of Figure 4.
Figure 6 shews another form; here the winding is on the boss of a disc a on the
axis band this has two series of horns a¹ and aº.
On the part d there are two corresponding series of horns d'and do. There are
suitable intervals between the horns as in the previous examples and they are so
arranged that alternately the magnetic circuit is complete through iron, (excepting
at narrow air spaces) and open, there being in the latter case comparatively wide
intervals between metal and metal.
Figure 7 is similar to Figure 3 except that the axis 6 is so mounted and the
extremities of the horns are so formed that the two axes may deviate to an
appreciable extent from-exact alignment.
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 I
claim is
•
1. An electric clutch consisting of two parts of iron the one on an axis driven by
a motor and the other upon a second axis which it is required to drive from time to
time; such parts being able to revolve in close proximity but without contact and
being provided with coils in which when desired 'án electric current can be caused
to pass; the whole arrangement being such that inagnetic-circuits are established
lying partly in the one part and partly in the other part which result in the produc-
tion of the requisite magnetic drag.
"
2. In an electric clutch such as is defined by the preceding claim so fashioning
the iron parts that they present a series of poles with intervals between them as
herein set forth.
3. Electric clutches substantially as represented by the annexed drawings.
Dated this 13th day of July 1891