Improvements in Electrical Switches.
Year: 1890

page_text: Date of Application, 17th Nov., 1890;
Complete Specification Left, 17th Sept., 1891-Accepted, 7th Nov., 1891
PROVISIONAL SPECIFICATION.
Improvements in Electrical Switches.
I, HENRY JAMES PIERCE of South Acton Works, Beaumont Road South
Acton in the County of Middlesex Electrical Engineer do hereby declare the
nature of this invention to be as follows
-
This invention relates to electrical switches and its object is to produce a quick-
break switch in which the making point of contact is at a different place from the
leaving point of contact at both surfaces of contact.
To this end I provide the oscillating arbor of the switch with a contact lever
pivoted excentrically to a boss or arm ou said arbor and provide a spring tending
to press said lever into a position tangential to said boss so that the outer end of
the lever shall be usually at a less radial distance from the centre of rotation (the
axis of the arbor) than it is when held back against the tension of said spring. For
the fixed contact or contacts between which electrical connection is made by said
contact lever, plates are used of the nature of leaf springs, having two lateral
projections at different radial distances from the arbor aforesaid, so that in bringing
the lever into contact it meets only the nearer lateral projection whereas in moving
it out of contact the frictional resistance of the surfaces in contact holds back the
lever while the arbor is rotated so that the lever is thrust outward and when
eventually leaving the contact, it leaves at the further projection, leaving also with
a quick break by reason of the action of the spring in the lever which was brought
into tension by the backward retention of the lever due to the resistance of the
surfaces in contact. The action of the contact surfaces herein described also tends
to keep said surfaces clean and even.
Dated this 17th dev of November 1890.
HERBERT & CO.,
Agents to Applicant.
COMPLETE SPECIFICATION.
Improvements in Electrical Switches.
I HENRY JAMES PIERCE of South Acton Works, Beaumont Road South
Acton in the County of Middlesex, 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 relates to electrical switches and its object is to produce a quick
break switch in which the making point of contact is at a different place from the
leaving point of contact at both surfaces of contact.
In the drawing
Fig. 1 is a plan.
Figs. 2 and 3 are back and front elevations respectively of the improved
switch.
I provide the oscillating arbor C of the switch with a contact lever A pivoted
eccentrically at A¹ to a boss or arm B on said arbor and provide a spring E tending
to press said lever into a position tangential to said boss so that the outer end of
the lever shall be usually at a less radial distance from the centre of rotation
(the axis of the arbor C) than it is when held back against the tension of the
spring E.
For the fixed contact or contacts, between which electrical connection is made by
said contact lever, plates H are used of the nature of leaf springs having two lateral
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page_text: projections H H at different radial distances from the arbor aforesaid so that in
bringing the lever into contact it meets only the nearer lateral projection H¹
whereas in moving it out of contact the frictional resistance of the surfaces in
contact, holds back the lever while the arbor C is rotated so that the lever A is
thrust outward and when eventually leaving the contact it leaves at the further
projection H leaving also with a quick break by reason of the action of the spring E
in the lever which was brought into tension by the backward retention of the lever
due to the resistance of the surfaces in contact. The action of the contact surfaces
herein described also tends to keep said surfaces cleau and even. Ilare terminal
binding screws.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is
In a switch the combination of the boss B on the arbor C with the lever A and
spring E forming a knee joint substantially as specified with the contact plate H
having the two arms H H one at a greater radial distance from the axis of the
arbor C than the other for the purpose specified.
Dated this 17th day of September 1891.
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicant.