Year: 1888

page_text: Date of Application, 6th July, 1888
Complete Specification Left, 8th Apr., 1889
Complete Specification Accepted, 11th May, 1889
WILLIAM MACKIE Turks Head Yard, Turnmill Street in the county of Middlesex
Electrical Engineer do hereby declare the nature of this invention to be as
follows:-
The object of my invention is to make a switch or electric contact breaker & inaker
so that the metallic connecting piece assumes a positive position independently of
the absolute control of the handle or actuating mechanism.
To accomplish this I fix one end of a spring to a crank pin (or other suitable
device) & the other end of the spring is fixed permanently either to the case of the
switch or on to the base of the switch.
.
The position in which this spring is placed in relation to the connecting piece of
the switch is such that when it has the least tension on it the connecting piece shall
be either right off or right on.
The crank is (preferably) not a fixture to the handle or actuating parts of the
switch but has a certain amount of back lash or lost time before the said handle. is
able to move it.
The crank pin is prolonged so that it catches the side of the connecting piece of
the switch.
7
Now on moving the handle to turn the switch off the direction will be such that
it takes up the back lash between it & the crank, it will then be able to turn the
crank which will elongate the spring and eventually place the spring in such a
position that it tends to pull the crank on the other side of its centre. When this
position is obtained the crank pin catches the connecting piece of the switch also on
the other side of its centre. On continuing the motion of the handle the pin will
then commence to drive the connecting piece off the contact pieces until the spring
Price 7

page_text: is capable of pulling it off itself when it will do so to the extent of the amount of
travel or back lash between the crank & the handle which is enough for the crank pin
to knock the connecting pieces right off the contact pieces & vice versa.
The crank pin could be made to impart a backwards & forward sliding motion to
the connecting piece of a switch.
improvements relating to Switches for Electrical Purposes.
WILLIAM MACKIE Turks Head Yard, Turnmill Street 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 :-
The object of my invention is to make a switch or electric contact breaker & maker
so that the metalic connecting piece assumes a positive position independently of
the absolute control of the handle or actuating mechanism.
To accomplish this I fix one end of a spring to a crank pin A. (or other suitable
device) and the other end of the spring B. is fixed permanently either to the case of
the switch or to the base of the switch.
The position in which this spring is placed in relation to the connecting piece C of
the switch is such that when it has the least tension on it, the connecting piece C
shall be either right off or right on.
The crank A, is (preferably) not a fixture to the handle D. or actuating parts of the
switch but has a certain amount of "back lash," or lost time before the said handle is
able to move it.
;
The crank pin A is prolonged so that it catches the side of the connecting piece C
of the switch.
Now on moving the handle to turn the switch off, or on the direction will be such
that it takes up the back lash E. between it & the crank, it will then be able to turn
the crank A which will elongate the spring and eventually place the spring in such
a position that it tends to pull the crank on the other side of its centre F.
When this position is obtained, the crank pin catches the connecting piece of the
switch, also on the other side of its centre F.
On continuing the motion of the handle, the pin will then commence to drive the
connecting piece C. off the contact pieces until the spring is capable of pulling it off

page_text: itself, when it will do so to the extent of the amount of travel or back lash" between
the crank and the handle, which is enough for the crank pin A to knock the connecting
piece C right off the contact pieces & vice versa.
The crank pin could be made to impart a backward & forward sliding motion to the
connecting piece of a switch.
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
1st. I claim a loose driving crank having "back lash" or lost time between the
driving pin of the handle and the crank pin itself and making the crank pin pull or
push on or off the connecting pieces of an electric switch in connection with a spring
substantially as described.