Improvements in Electrical Switches.
Year: 1889

page_text: Date of Application, 11th Dec., 1889
Complete Specification Left, 10th Sept., 1890-Accepted, 25th Oct., 1890
PROVISIONAL SPECIFICATION.
Improvements in Electrical Switches.
I, HENRY BAYLEY, trading as Bayley Brothers, of Selborne Works, Walsall in the
County of Stafford, Electrical Fitting Manufacturer, do hereby.declare the nature of
this invention to be as follows:-
This invention has for its object the construction of electrical switches in such
manner that the contact pieces (or contact makers and breakers) may make and
break contact with the terminal plates or blocks simultaneously over the entire
bearing area between such parts and be also capable of rubbing contact therewith, such
rubbing contact being preferably simultaneous with the area contact, the purpose of
the invention being to avoid or greatly reduce the tendency to sparking
occasioned by the area of the bearing surfaces of the contact pieces being brought
into and out of contact gradually (though rapidly) with the terminals as in the
forms of switches commonly employed and to avoid the inconvenience due to the
accumulation of dust between the bearing surfaces of the switches now employed in
which full area of contact takes place and is broken immediately but in which
there is no rubbing contact.
According to a convenient application of this invention a clutch having inward
teeth is fixed to and near the outer end of a central pin which is itself fixed to the base
or insulating block. A corresponding clutch, having outward teeth capable of gearing
with those of the outer clutch, is mounted on the pin on the inner side of the first
mentioned clutch and is capable of turning loosely on the pin. A square is formed
on the back of the inner clutch, and the contact piece of the switch has a square
hole formed therethrough and is passed over the square projection along which it is
capable of sliding but upon which it cannot turn. The contact piece is pressed
outwards by a spiral spring around the pin or by other suitable spring, and a bow or
other spring is interposed between the contact piece and the inner clutch. A key
or turning-piece is mounted to be capable of turning loosely on the outer end of
the pin, and studs project inwards therefrom which pass, respectively, alongside of
ears formed on the sides of the inner clutch. As the key is turned the studs
push against the ears on the inner clutch and cause it, together with the contact
piece, to turn also, and simultaneously therewith the inner clutch is forced inwards
by the outer clutch and the contact piece thus brought into full area and also rubbing
contact with the terminals. The teeth of the clutches are so formed that the inner
clutch is continued to be pressed inwards for a short distance after the contact has
been made, the spring between the contact piece and inner clutch yielding and
thus increasing the pressure of the contact-piece on the terminals.
to enable the operator to readily put on the full pressure without risk of accidentally
turning the contact piece too far and thus breaking the contact, the teeth are so
shaped that when the full pressure has been brought thereon the contact piece
may be continued to be turned for some distance in the same direction without
breaking the contact, the pressure remaining constant; and the rear ends of the teeth
are formed as straight abutment, and when it is desired to break contact the key is
turned further in the same direction as before until the rear ends of the teeth of
the inner clutch coincide with those of the outer clutch, when the contact piece
and inner clutch are suddenly forced outwards by the coil spring and thus the whole
area of the contact is simultaneously broken. A spring guard is fixed to the base
in position to prevent the contact piece being turned backwards out of contact with
the terminals.
Dated this Tenth day of December 1889.
In order

page_text: COMPLETE SPECIFICATION.
Improvements in Electrical Switches.
I, HENRY BAYLEY, trading as Bayley Brothers, of Selborne Works, Walsall in the
County of Stafford, Electrical Fitting Manufacturer, 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 the construction of electrical switches in such
manner that the contact pieces (or contact makers and breakers) may make and break
contact with the terminal plates or blocks simultaneously over the entire bearing
area between such parts, such contact being made by a rubbing movement of the
parts upon one another; the purpose of the invention being to avoid or greatly
reduce the tendency to sparking occasioned by the area of the bearing surfaces
of the contact pieces being brought into and out of contact gradually (though
rapidly) with the terminals, as in the forms of switches commonly employed, and
to avoid the inconvenience due to the accumulation of dust between the bearing
surfaces of the switches now employed in which full area of contact takes place and
is broken immediately, but in which there is no rubbing contact.
This invention is illustrated by the drawings herewith, of which
Figure 1 is an elevation of a switch constructed according to this invention.
Figure 2 an elevation of the same taken at right angles to Figurel.
Figure 3 a vertical section taken through the centre of the switch and corresponding
to the elevation Figure 1, and
Figure 4 a sectional plan taken on line y y of Figure 2.
In Figures 1 and 3 the contact piece is clear away from the terminal plates, but in
Figure 2 it is shown to be bearing thereon.
A round pin A is fixed to the centre of a slate, vulcanite, or other insulating
block B which forms the base of the switch. The terminal plates C are fixed upon
the face of this block by means of screws a passing up through holes in the block
and screwed into the plates, and the leads are connected by means of the terminal
screws b. A clutch D having inward or downward teeth d is formed with or fixed
rigidly to the pin A, and a corresponding clutch E having outward or upward
teeth e is carried so as to be capable of turning easily around, and sliding endways
along, the pin A. This clutch E is provided with a sleeve c on its under side, which
also fits easily around the pin A, but is formed square outside. The contact piece F
has a square opening through its centre and is passed up over the end of the sleeve c,
as shewn, and between the underside of the clutch E and the upper face of the
contact piece F is interposed a bridge-piece G, formed of brass plate or other material
which will give some elasticity and allow the ends to spring slightly as pressure is
brought thereon. The contact piece F is constantly pressed outwards against the
ends of the bridge-piece G, by means of a spiral spring which encircles the
lower end of the pin A and bears up against the underside of the contact piece; and
to enable a considerable length of spring to be used for this purpose the pin A
is soldered or brazed into the bottom end of a ferrule H which is of sufficiently
larger diameter than the pin A to allow room for the spiral spring between the
exterior of such pin and the interior of the ferrule. The ferrule H may be con-
veniently fixed in the block B in the manner shewn, that is by forming it with a
collar g at its upper end and screwing a collar hon to its lower end. A pin i, pro-
jecting from the side of the ferrule and lying within a recess formed therefor in the
block B, securely prevents the ferrule from turning in the block. The upper end j of
the pin A is, preferably, reduced in diameter, as shewn, and over such portion is placed,
so as to turn easily there-around, an insulating key or turning-piece J, to the lower
face of which is fixed, by means of screws r, a plate K carrying studs k which engage
with ears formed with the clutch E, so that as the key Jis turned in the direction
indicated by the arrow m, Figure 4, the clutch E is turned also. The teeth on the
clutches D and E, respectively, are formed inclined or curved as seen most .clearly in

page_text: The
the side elevation thereof, Figure 1. and thus as the teeth e are turned with the
clutch E they are forced down, by the teeth d of the clutch D, into the position
shewn by Figure 2, the clutch E carrying down with it the bridge-piece G a contact
piece F, such bridge-piece and contact-piece turning therewith also as they are
mounted on the square sleeve c which is formed with or fixed rigidly to such clutch;
and thus the contact piece is forced down flat upon the two terminal plates C, causing an
instantaneous full contact area between the bearing surfaces of the contact piece and
terminal plate, respectively, on each side of the switch, simultaneously with a rubbing
motion between the surfaces caused by the turning of the contact piece.
teeth d and e, respectively, are so proportioned that after full area contact has been made
the clutch E will be continued to be forced down as it is continued to be turned for some
little distance in the same direction, the extra pressure thus put upon the contact piece
being conveyed through the elastic bridge-piece G; but in order to enable the
operator to readily put on the full pressure without risk of accidentally turning
the contact piece too far, and thus breaking the contact, the teeth are formed flat or
straight for a short distance along their parts of greatest depth or projection, that is
at the parts s Figure 1, so that as the key is still further turned in the same direction
no further pressure will be brought upon the contact piece F. The contact piece is
shewn by Figure 2 as bearing with full pressure on the terminal plates. The rear
ends of the teeth are formed as straight abutments n, and when it is desired to break
contact the key is turned still further in the direction indicated by the arrow m until
the rear ends of the teeth e coincide with those of the clutch D as shewn by Figure 5
(which is a detached side elevation of the clutches shewing the rear ends of the teeth e
to be just passing beyond the corresponding ends of the teeth d), when the contact
piece F and clutch E are suddenly forced outwards or upwards by the spring f,
carrying up the teeth e into the hollows between the teeth d, and thus the whole area
of contact between the contact-piece and terminal plates is instantaneously broken.
The ears project somewhat above the teeth e, so as to be in gear with the studs k
when the clutch E is in its lowest position.
By this invention, the electrical connection between the terminal plates or blocks
is made by rubbing contact simultaneously through the entire bearing area between
the contact piece and terminal plates or blocks, and thus the tendency to sparking is
avoided or greatly reduced. It is not, however, essential to the successful use of the
invention that the electrical connection shall be formed through the whole bearing
area between the contact piece and terminal plates instantaneously, as the purpose of
the invention will be answered more or less completely if such connection is formed
through a considerable proportion of such area instantaneously, as would be the case,
for instance, if a considerable portion only of the width of the contact piece came first
against the ends of the plates before the remaining width thereof was slid
thereover.
In order to prevent the contact-piece from being turned backwards out of contact
with the terminals, a spring guard L is carried in such position that it is pressed upon
and forced downwards or inwards by the contact piece as the latter is brought to its
bearing, and as the contact piece is continued to be turned it passes over the guard,
which consequently springs up behind it and securely prevents it from being
turned backwards. This guard, consists conveniently, in the arrangement shewn in
detached view Figure 6 that is to say, of a pin carried within a case o and pressed
outwards by means of a spiral spring p within such case. The pin L has an enlarged
head, as shewn, to prevent it being forced out of the case, and the case is held to the
insulating block. by means of a screw q screwed into the end of the case and bearing
against a shoulder formed in the block. The spiral spring p is compressed between
the head of the pin L and the end of the screw q. A stud k¹ (Figures 1 and 2)
corresponding to the studs k before described, is carried down from the plate K in
front of one of the ears l, and thus while the guard L prevents the contact-piece from
being turned backwards out of contact, the stud k prevents the key from being turned
backwards independently of the clutch E and contact-pince F.

page_text: A sheet metal case M, of the usual character, covering in the whole of the mechanism,
is shewn in section by broken lines Figure 1.
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
1 claim is
1. An electrical switch in which electrical connection between the terminal plates or
blocks is made by rubbing contact simultaneously through the entire bearing area (or
through a very considerable proportion thereof) between the contact piece and terminal
plates or blocks, substantially as described, for the purpose set forth.
2. An electrical switch in which a contact piece is brought inwards or downwards
against or upon terminal plates or blocks by a turning movement which causes a
rubbing contact simultaneously with the area contact, substantially as described for
the purpose set forth.
3. An electrical switch in which the contact piece is simultaneously pressed inwards
or downwards, and turned, by the aid of an inner clutch which is forced inwards or
downwards as it is turned in contact with an outer clutch, substantially as described
and shewn, for the purpose set forth.
4. In an electrical switch in which the contact piece is turned as it is moved
inwards or downwards towards the terminal plates or blocks, the employment of a
spring guard to allow the contact piece to be brought against the plates and to
prevent it being turned backwards out of contact therewith, substantially as
described.
5. An electrical switch in which the contact piece is turned as it is moved
inwards or downwards against or upon the terminal plates, constructed substantially
as described with reference to the drawings herewith, for the purpose set forth.
Dated this 9th day of September 1900
QUAS
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicant.