Improvements in Electric Switches.
Year: 1891

page_text: Date of Application, 8th Oct., 1891
Complete Specification Left, 8th July, 1892-Accepted, 20th Aug., 1892
PROVISIONAL SPECIFICATION.
Improvements in Electric Switches.
I, WILLIAM BROOKS SAYERS, of Glenwood, Bearsden near Glasgow, in the
County of Dumbarton, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention has reference to a construction of electric switch in which
electrical connection is made between insulated contacts or conductors by a metal
ring of any convenient section loosely mounted upon a movable holder by which
it is capable of being forced between or against the contacts so as to make
connection therewith.
In one arrangement, the holder is arranged within a suitable case and is formed
with a cam groove or surface that acts against a fixed pin or abutment, the
arrangement being such that when the holder is partly rotated by a suitable
handle, it is caused to move endways against the action of a spring and force
the metal ring between and against the contacts to be electrically connected, and.
when the holder is partly turned in the opposite direction the spring reacts and
forces the holder into its original position and breaks the electrical connection.
In a modified construction, the holder is formed with a double cam surface that.
acts against two fixed set screws. For concentric wiring the switch case is made-
of metal and the contacts are in the form of short metal rods carried by bushes
of insulating material screwed or otherwise removably fixed in externally screw-
threaded tubular extensions of the metal case to which the outer conductor can
be readily connected. In ordinary double wiring the case is formed with additional
side passages through the end insulating pieces for the second or return conductor.
The loose ring may advantageously be made of thin hard rolled or spun metal
of channel form in cross section so that it can be compressed when forced between
the contacts. By making the ring loose it will, when the holder is turned to the
"off" position, be caused to rotate independently of the holder and will con-
sequently be likely to present fresh surfaces to the insulated contacts each time
the switch is turned into the "on" position.
In another construction of switch according to this invention the loose ring is
replaced by a metal connecting piece that is carried by and extends through the
holder. This connecting piece may be a rigid pin or a coiled spring.
When
a coiled spring is used its central portion may advantageously be made to tightly
fit the hole in the holder, and its ends may be twisted to serve as contacts or
may be provided with separate caps for this purpose.
The insulated contacts carried by the switch case may be each formed with an
enlarged inner end between which and its insulating bush may be placed a métal
washer that bears against a washer of yielding material such as asbestos.
The holder, which may be of porcelain, can be made in one with the handle for
turning it or separate therefrom. In the latter case one of them is provided with
pins that enter holes in the other so that rotary movement can be transmitted from
the handle to the holder, a spring or springs being arranged between the two.
கட் "
Out 1001

page_text: COMPLETE SPECIFICATION.
Improvements in Electric Switches.
I, WILLIAM BROOKS SAYERS of Glenwood, Bearsden near Glasgow, in the
County of Dumbarton, Electrical 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 reference to a construction of electric switch in which
electrical connection is made between insulated contacts or conductors by a metal
ring of any convenient section loosely mounted upon a movable holler by which it
is capable of being forced between or against the contacts so as to make connection
therewith:
In one arrangement, the holder is arranged within a suitable case and is formed
with a cam groove or surface that acts against a fixed pin or abutment, the
arrangement being such that when the holder is partly rotated by a suitable
handle; it is caused to move endways against the action of a spring and force the
metal ring between and against the contacts to be electrically connected, and when
the holder is partly turned in the opposite direction the spring reacts and forces the
holder into its original position and breaks the electrical connection. In a modified
construction the holder is formed with a double cam surface that acts against two
fixed set screws. For concentric wiring the switch case is made of metal and the
contacts are in the form of short metal rods carried by bushes of insulating
material screwed or otherwise removably fixed in externally screw-threaded tubular
extensions of the metal case to which the outer conductor can be readily connected.
In ordinary double wiring the case is formed with additional side passages
through the end insulating pieces for the second or return conductor.
The loose ring may advantageously be made of thin hard rolled or spun metal of
channel form in cross section so that it can be compressed when forced between the
contacts. By making the ring loose it will, when the holder is turned to the "off"
position, be caused to rotate independently of the holder and will consequently be
likely to present fresh surfaces to the insulated contacts each time the switch is
turned into the "on" position.
The holder which may be of porcelain, can be made in one with the handle for
turning it or separate therefrom.
In the latter case one of them is provided with pins that enter holes in the other
so that rotary movement can be transmitted from the handle to the holder, a spring
or springs being arranged between the two.
In the accompanying drawings
Figs. 1. 2. and 3. respectively represent three views of a switch constructed
according to this invention adapted for concentric wiring--and Figs. 4. 5. and 6.
respectively represent three views of a switch adapted for double wiring with a
modified form of flexible ring.
Figs. 7 and 8. represent respectively plan and edge views of the said modified
form of flexible ring.
In each of the views A. is the holder, B the flexible ring and C. C. the contacts
between which electrical connection is to be made and broken by the action of the
switch. D. D. are the insulating blocks.
Referring to Fig. 1. which represents a sectional view of a switch for concentric
wiring the flexible ring B. is made of thin spun copper, one edge being spun into
the recess formed in the holder A. to receive it. The lower end of the holder A is
formed with a cam surface that acts against the fixed pin E while the upper end is
formed with a shoulder or collar F. G. is a spiral spring which abuts against the
internal ledge formed at the upper end of the case H.
The cables I. 1. are united with the case in the manner described in Specifi-
cation 16958 A.D. 1891.

page_text: The action of the switch is as follows; Suppose the holder to be in the "off"
position which is indicated by the dotted lines and that it is rotated one quarter
turn from right to left the action of the cam surface upon the fixed pin E. will
cause the holder to move edgeways and so to force the flexible ring B. in between
the contacts C. C. and thus establish electrical connection between them at the
same time the spiral spring G is compressed and on again rotating the holder back.
into its former position the spring reacts and tends to cause a quick break and also
to maintain the holder in the "off" position.
Fig. 4. is a sectional view of a switch for double wiring constructed according to
my invention. Figs. 5 and 6. are respectively a plan and an end view of same.
Referring to Fig. 4. A. is the holder which may conveniently be made of
porcelain. B. the Hexible ring which is composed of two thin hardrolled copper
rings laid together and loosely secured upon the holder A. by means of two
pins J. J. passing through the holder and having their ends turned one in one
direction and one in the other direction to prevent them from moving endways in
their respective holes. K. is a pin which is fixed into the holder A and works upon
the cam surface formed on the inside of the cover of the case H. G. is the spiral
spring. C. C. are the contacts. D. D. are the insulating blocks, and 7 represents
the through connection for the second conductor. The pins J. J. which serve to
keep the flexible ring B. in its position on the holder A. are arranged so as to be
approximately at right angles to the points of contact when the switch is on the
on position. By this means full advantage of the flexibility of the ring is
obtained. In Fig. 1. the holder A. is shown in the "on" position. When the
holder is rotated one quarter turn from left to right the pin K. slides under the
reaction of the spring G. on the cam surface shewn on the inside of the cover of
the case H. and the holder thus moves endways in the direction indicated carrying
the flexible ring B. with it and thus breaking the electrical connection.
"
My invention can be applied to switches of any size for switch board or other
work and when so applied the case H. can usually be dispensed with.
Having now particularly described and ascertained the nature of the inven-
tion and in what manner the same is to be performed; I declare that what I
claim is:
In an electric switch making the contact making and breaking device in the
form of a flexible metal ring loosely mounted upon an insulated holder, the holder
being connected directly or through intermediate mechanism with an operating
device or handle by means of which the said loose flexible ring is forced in
between or against the contacts or points between which it is desired to make
or break electrical connection substantially as herein described and illustrated in
the drawings and for the purpose specified.
Deted this 7th day of July 1892.