Year: 1889

page_text: Date of Application, 30th Jan., 1889
Specification Accepted, 9th Mar., 1889
1, GEORGE HERBERT WHITTINGHAM of Pikesville in the City of Baltimore, County
of Baltimore, State of Maryland, United States of America, Electrician, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:-
This invention has relation to an electric switch designed for use in starting and
stopping the supply of an electrical current to a conductor or conductors employed in
transmitting the same for lighting or other mechanical purposes the object of the
invention being primarily to so control the delivery of the electrical current to the
motor or to the conductors that the supply shall be gradual in order that the motor or
the mechanism to which the conductors lead shall be prevented from any injurious effects
arising from an overcharge of the current. In the application of the invention for
controlling the supply of the current to an electric motor and to a line of supply as
for example lighting devices, the construction arrangement and operation of the
several parts hereinafter described remains the same; but in one instance the
supply passes from the line through the switch to the motor, and in the other
instance from the line through the switch to the point of work.
The main purpose, object and advantage of the invention that is the gradual supply
of the electrical current involves the interposition of any well known extraneous
resistance and a certain particular construction of mechanical devices for rendering
the control of the said supply automatic.
Other objects and advantages will appear in the following description.
Referring to the drawing
;-
Fig. 1 is a plan of a switch constructed in accordance with my invention, and
Fig. 2 is a side elevation looking in the direction indicated by the arrow in
Fig. 1.
Like numerals refer to like parts in both the figures.
1 represents the base which may be the bottom or back of a casing having a glass
in its front to protect the operative parts of the switch from dust and moisture.
2 and 3 represent binding posts for the incoming and outgoing lines. 4 represents a
similar post for the field and armature line 12 of the motor X. 5 represents a binding
[Price 8d.]

page_text: post leading from the field of the motor, while 6 represents the point of connection
of the associate armature line 44 with the resistance 7. The resistance 7 comprises
a series of insulated plates 7 a connected with the coils 7 b.
The posts 2 and 4 are connected by a conductor 8 having an interposed fusible
section 8 a held in position by clamps S of conducting material electrically connected
with the conductor S. The latter ends in clamping contact plates 9 mounted upon a
block 1 of insulated material and constitutes one terminal of the circuit. Similar
contact plates 11 are mounted on the block 10 a distance from the plates 9 and are
electrically connected with the conductor 12 which is a continuation of the con-
ductor 8 and extends to the motor X. From one of the clamps 86 the conductor 8
extends to a magnet 13 and from the magnet to the clamp 14 with which a latch 15
is adapted to make contact and being of conducting material serves for the passage of
the current therethrough and to its pivot 16 from which to the clamp 9 the con-
ductor & extends.
A keeper 17 is provided to swing in front of the poles of the magnet 13 and into a
notch 18 formed in the end of the latch. A post or other stop 19 projects from the
base to limit the movement of the latch in one direction which movement is caused
by a coiled spring 20 secured at one end 21 to the base and at the other to a
disc 22 of non-conducting material secured to the latch and having a notch 23 in its
periphery.
At or about the centre of the base is a standard or stud 24 on which is pivotally
mounted a brass disc 25 having diametrically opposite depending lugs 26 and 27 and
a third lug 28. The operating lever 29 of the switch is secured in any suitable
manner to the disc and is provided with a contact plate 29 a which is adapted to reach
from one to the other of the clamping plates 9 and 11 when brought into contact
therewith to complete the circuit. On the standard 30 and below the disc is pivotted
independently a resistance bar 30 which terminates in contact plates 31 which are
adapted to bear against the upper and lower surfaces of the plates 7 a of the resistance.
Between the pivotted and free ends of the resistance bar as at 32 is pivotally connected
a resistance bar governing device the function and object of which is to control the move-
ment of the plates over and along the resistance. In this instance the governing device
is a dash pot having a rod 34 extending from its closed end and pivotally connected
with the bar 30 while its piston rod 35 is pivotally connected with the base at 36 and
its head is provided with one or more openings or ports 37 so that oil or other desirable
liquid within the dash-pot is caused to pass through said ports or openings and thus
to regulate and control the movement of the bar along the resistance.
In this instance the dash pot rod is suspended at 36 so that the weight of its
cylinder and of the resistance bar is the moving force which causes the bar to move
along over the resistance but it is apparent that any convenient arrangement of a
spring may be employed instead of the suspended dash-pot. For example said spring
may be connected with the resistance bar and with the lever as shown by dotted
lines at 38.
By the means just described al movement of the bar 30 in one direction
is provided for, while its movement in the opposite direction is caused by
a depending lug 26 on the brass disc 25 which is brought into operation
in that movement of the lever which occurs in breaking the connection with
the plates 9 and 11. A spring 39 extends from a pin on the lever to
a stud 40 arranged with relation to the stud 25 so as to withdraw the lever after it
has passed its centre of motion in either direction; thus insuring on the one hand
complete connection with the plates 9 and 11 and on the other hand a complete return
of the resistance bar. Now in order to insure a good contact of the plate 29 a with
the plates 9 and 11 in making the circuit a hook 41 is pivotted on the standard 40 and
it is adapted to take into the notch 42 in the bar 30 so that the depending lug 28 on
the brass disc 25 must reach said hook and force it out of said notch before a complete
contact occurs between said plates 29 a 9 and 11. Instead of removing the hook
mechanically by the lug 28 it may be accomplished electrically by arranging a
magnet 28 adjacent to the hook as shown by dotted lines and placing said hook

page_text: in the circuit 8 between the clamp 14 and the magnet 13 so that said hook in that
case will also not be removed or released from the bar 30 until the circuit is com-
pleted by the lever.
On the right of the switch is shown the conductor 43 extending from the post 3 to
the pivot of the resistance bar and the current is conducted along the same t'irough
the bar and the resistance to the point 6 where it takes the conductor 44 to the
armature of the motor. Another conductor 45* extends (preferably beneath
the base) from the post 3 to the post 5 and from thence to the field line 12* of
the motor.
Its
As above stated the latch 15 is thrown in one direction by a spring 20.
movement is caused in the opposite direction by the depending lug 27 on the
disc 25 when the lever 29 is thrown to the right. Now, it will be seen that
taking the parts in the position illustrated in Fig. 1 the circuit is broken at the
plates 9 and 11, and that in order to complete the same the switch lever must be
thrown over so that the plate 29 a thereof shall connect the two terminals 9 and 11.
By this act instead of throwing the supply of electricity upon the companion line of
the circuit to that which is closed by said plate 29a said supply is caused to pass
through the resistance 7 and as the switch lever is thrown over, the hook 41 being
removed by magnet 28* from the recess 42 the dash pot and resistance bar fall by
gravity carrying the plates 31 along over the resistance gradually as said bar is
allowed to move or is controlled in its movement by the mechanical resistance of the
liquid within the cylinder of the dash pot as it passes through the port 37 of the
piston thereof.
At this point it is noted that in case the current should be abnormal to such a
5 degree as to injure the motor the magnet 13 retracts the keeper 17 and the latch 15
is thrown from the contact with the plates 14 by the spring 20 thus breaking the
circuit and stopping the motor. The poles of the magnet are adjustably supported in
the bracket 14 by set screws 46 so that said magnet may be adjusted to withdraw the
keeper when an excessive amount of current or one required beyond that for the work
to be performed is conducted to the magnet.
As a further precaution the fusible strip 8 a is provided in order that in case the
magnet 13 should fail in its intended operation the current if sufficiently abnormal
shall melt the strip and thus break the circuit so that in either case the motor is
protected from injury by an excessive amount of current. In case the latch is
released the current broken and the motor stopped, the operator has only to move said
switch lever to the right to again make the circuit.
Sparking is prevented by insulating and separating the plates 9 and 11 and
extending the plate 29 a to reach from one to the other.
I deem it proper to state the several novel features of my invention are capable of
being used successfully without employing the intermediate cut-off, involving the
magnet 13 and latch 15 and other mechanical connections with the switch lever may
be used. For example the conductor 8 may be extended directly from the clamp S
to the contact plates 9 as illustrated by dotted lines Y. In this modified construction
the operation of the switch so far as regards the action on the remaining parts and
especially of the governor and resistance bar connected and cooperating with the
switch lever described which would attain the primary objects of the invention,
I do not limit my invention to the use of all the features herein shown and
described.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what [
claim is ;-
1. A switch comprising an operating lever carrying a circuit closing plate a
resistance an arm extending from the operating lever to the resistance and con-
nected with a dash-pot and a device connected with the operating lever for
maintaining the arm against movement until said operating lever is connected with
the circuit which it is adapted to close substantially as specified.

page_text: 2. The combination with the lever and resistance of a switch and a latch arranged
in the path of the lever to be operated in one direction and a spring for operating the
latch in the opposite direction a keeper and a magnet for controlling the keeper
substantially as specified.
3. In a switch and electrically connected with the conductors thereof a resistance a
resistance bar mechanism substantially as described for automatically controlling its
movement in one direction the switch lever proper a latch having mechanical
connection with said lever for movement in one direction a spring or its equivalent
for moving it in an opposite direction a keeper and a magnet for automatically
releasing the latch substantially as specified.
4. In a switch and in combination with its lever a resistance a resistance bar
mechanically connected with the lever for its operation positively in one direction and
a governor for automatically controlling the operation of the resistance bar in the
opposite direction substantially as specified.
5. In a switch the combination of the lever 29 having at its pivotted end a disc 25
having the lug 26 depending from the disc a standard 24 for supporting the lever and
a bar 30 independently pivotted to said standard and extending to the resistance
substantially as specified.
6. The combination of the resistance 7 its bar arranged to move over the resistance a
governing device substantially as described connected therewith the switch lever 29
terminating in a disc 25 and having independent movement relative to the bar 30 and
provided with means for moving said bar in the opposite direction to that of the
movement produced by the governing device substantially as specified.
7. The combination of the lever 29 bar 30 and disc 25 having lugs 26 and 28 and
hook 41 the bar 30 and hook 41 being arranged in the path of said lugs substantially
as specified.
8. The combination of the lever 29 disc 25 having lug 27 and latch 15 having
notched disc 22 arranged in the path of said lug substantially as specified.
9. The combination of the magnet 13 keeper 17 latch 15 contact plate 14 in the
path of the latch the non-conducting disc 22 on the latch the lever 29 its
depending lug 27 in the path of the disc with conductor 9 substantially as
specified.
10. The combination with the switch lever 29 a resistance and resistance bar
and a governing device substantially as described of a hook adapted to take into
said bar and means substantially as specified for releasing said hook at about the
time that the circuit is completed by the operation of said lever substantially as
specified.
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1000