Year: 1899

page_text: Date of Application (in United Kingdom), 30th Dec., 1899
Complete Specification Left, 28th Sept., 1900-Accepted, 24th Nov., 1900
I, ALEXANDER JAY WORTS, of Westinghouse Building, Pittsburg, in the Courty
of Allegheny, and State of Pennsylvania, U.S.A., Electrical Engineer, do hereby
declare the nature of this invention to be as follows:-
My invention relates to lightning arresters employed for preventing injury to
electric machines and circuits from charges of static electricity derived from the
atmosphere.
My improved lightning arrester is provided with a number of spark gaps and
with a resistance interposed in series with each gap the latter having the effect of
causing a discharge to divide among the several gaps thereby reducing the in-
tensity of the discharge along any one gap.
I have prior to this application used lightning arresters of this general character
as described for example in my United States Patents Nos. 509783 and 509784 of
28th November 1893 and my present invention consists in a specially compact
and convenient form of lightning arrester of this class.
In carrying out my invention one of the sparking terminals of the arrester is
divided into several parts all mounted on an insulating block and separated by
spark gaps from an undivided terminal mounted on the same block. Each division
of the divided terminal is furnished with a socket to receive the end of a resistance
rod the other ends of which rods are connected to the circuit to be protected or
to the earth.
A further improvement consists in a particular form of resistance rod which I
have devised for use in series with the spark gaps.
In the accompanying drawings I have shown a lightning arrester constructed
according to my invention.
Figures 1 and
displaced in Figure 2.
Figure 3 is a side elevation of one of my improved resistance rods, a portion of
the protecting sheath thereof being removed.
are perspective views of the arrester, one side plate being shewn
At
Referring to Figures 1 and 2 the undivided sparking terminal of the arrester is
constituted by two plates a secured one on each side of an insulating block b.
the side of each plate a is provided a strip of hard wood e arranged with its fibres
substantially perpendicular to the face of the insulating block and on the
FD 977

page_text: opposite sides of the strip are located the plates forming the divided sparking
terminal. Across the strips c are charred grooves arranged so as to connect the
plates with the plates a as shewn; these grooves constitute the spark gaps
and form a path which is very slightly conductive. To the outer ends of the
plates are attached sockets e each of which receives one end of a resistance
rod f, the other ends of said rods being received in sockets 9 which are connected
by a plate h. The sides of the device are enclosed by the plates one of which is
shewn displaced in Figure 2 and which plates are provided with a grooved strin k
in position to engage with the strip c of the block b. It will be clear that the
groove in the strip k crosses each of the grooves in the strip c and it forms therefore
an opening by which any gases due to a spark passing along the spark gaps can
escape.
The plate hand terminal a are severally connected to the circuit to be protected
and to earth.
The resistance rods which I prefer to use are formed of a mixture of graphite,
kaolin and some binding material such as starch for example, and I have found
that the rods are much better adapted for my purpose if they are merely compressed
and allowed to dry at ordinary temperatures in lieu of baking the same. Rods
made in this manner are, however, somewhat fragile and I therefore provide a
stiffening sheath 7, Figure 3, preferably extending throughout the greater portion
of the length of the rod: such a sheath is conveniently made of tough paper which
may be applied as follows:-
I first moisten a sheet of paper till it becomes pliable and then after allowing
the surplus moisture to dry off I smear it with shellac or other suitable adhesive
and roll it round the rod until a suitable thickness has been obtained.
My improved lightning arrester is exceedingly small and compact, but is not-
withstanding capable of dealing with large discharges. It will be understood of
course that the duplication of the parts shewn in the drawings is not necessary,
and that the number of gaps may be varied if desired.
Dated the 30th day of December 1899.
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.
Improvements in and relating to Lightning Arresters.
I, ALEXANDER JAY WURTS, of Westinghouse Building, Pittsburg, in the County
of Allegheny and State of Pennsylvania, United States of America, 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:-
My invention relates to lightning arresters employed for preventing injury to
electric machines and circuits from charges of static electricity derived from the
atmosphere,
My improved lightning arrester is provided with a number of spark gaps and
with a resistance interposed in series with each gap the latter having the effect of
causing a discharge to divide among the several gaps thereby reducing the in-
tensity of the discharge along any one gap.
I have prior to this application used lightning arresters of this general character
as described for example in my United States Patents Nos. 509783 and 509784 of
28th November, 1893, and my present invention consists in a specially compact
and convenient form of lightning arrester of this class.

page_text: In carrying out my invention one of the sparking terminals of the arrester is
divided into several parts all mounted on an insulating block and separated by
spark gaps from an undivided terminal mounted on the same block. Each division
of the divided terminal is furnished with a socket to receive the end of a resistance
rod, the other ends of which rods are connected to the circuit to be protected or
to the earth.
A further improvement consists in a particular form of resistance rod which I
have devised for use in series with the spark gaps.
In the drawings filed with my Provisional Specification I have shown a lightning
arrester constructed according to my invention.
Figures 1 and 2 are perspective views of the arrester, one side plate being shown
displaced in Figure 2.
Figure 3 is a side elevation of one of my improved resistance rods, a portion of
the protecting sheath thereof being removed.
Referring to Figures 1 and 2 the undivided sparking terminal of the arrester is
constituted by two plates a secured one on each side of an insulating block b. At
the side of each plate a is provided a strip of hard wood arranged with its fibres
substantially perpendicular to the face of the insulating block 6 and on the
opposite sides of the strip are located the plates d forming the divided sparking
terminal. Across the strips c are charred grooves arranged so as to connect the
plates d with the plates a as shown; these grooves constitute the spark gaps
and form a path which is very slightly conductive. To the outer ends of the
plates are attached sockets e each of which receives one end of a resistance
rod f, the other ends of said rods being received in sockets which are connected
by a plate h. The sides of the device are enclosed by the plates i one of which is
shown displaced in Figure 2 and which plates are provided with a grooved strip k
in position to engage with the strip c of the block b. It will be clear that the
groove in the strip & crosses each of the grooves in the strip e and it forms therefore
an opening by which any gases due to a spark passing along the spark gaps can
escape.
The plate h and terminal a are severally connected to the circuit to be protected
and to earth.
Rods
The resistance rods which I prefer to use are formed of a mixture of graphite,
kaolin and some binding material such as starch for example, and I have found
that the rods are much better adapted for my purpose if they are merely compressed
and allowed to dry at ordinary temperatures in lieu of baking the same.
made in this manner are, however, somewhat fragile and I therefore provide a
stiffening sheath 7, Figure 3, preferably extending throughout the greater portion
of the length of the rod: such a sheath is conveniently made of tough paper which
may be applied as follows:
.
I first moisten a sheet of paper till it becomes pliable and then after allowing
the surplus moisture to dry off I smear it with shellac or other suitable adhesive
and roll it round the rod until a suitable thickness has been obtained.
My improved lightning arrester is exceedingly small and compact, but is not-
withstanding capable of dealing with large discharges. It will be understood of
course that the duplication of the parts shown in the drawings in not necessary,
and that the number of gaps may be varied if desired.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed I declare that what
I claim is:-
1. A lightning arrester having a divided sparking terminal and a plurality of
resistance rods severally connected at one end to the divisions of the sparking
terminal, substantially as described.
2. A resistance rod having a stiffening cover or sheath attached thereto by
adhesive material.
3. The method of forming a resistance rod which consists in making a mixture

page_text: of comminuted conducting, non-conducting, and binding materials compressing
such mixture into the form desired and then applying alternate layers of adhesive
and stiffening materials.
4. A resistance rod manufactured as herein described.
5. A lightning arrester constructed and operating substantially as described
with reference to Figures 1 and 2 of the accompanying drawings.
Dated the Twenty-eighth day of Santambor 1000
F. W. LE TALL,
Chartered Patent Agent,
The Westinghouse Patent Bureau, Westinghouse Building,
Norfolk Street, Strand, London, W.C.