Improvements in Apparatus for Giving Motion to Reciprocating Parts, such as Percussive Tools, by Means of Electricity.
Year: 1889

page_text: Date of Application, 18th June, 1889-Accepted, 16th Nov., 1889
COMPLETE SPECIFICATION.
Improvements in Apparatus for Giving Motion to Reciprocating
Parts, such as Percussive Tools, by Means of Electricity.
A communication from abroad by HARRY NORTON MARVIN, of Syracuse, Onondaga
County, New York, United States of America, Electrician.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E. of the Agency for Foreign
Patent Solicitors 6 Lord Street, Liverpool, and 6 Bank Street, Manchester both in
the County of Lancaster and 323 High Holborn in the County of Middlesex, Civil
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to he particularly described and ascertained in and by the
following statement :-
The invention relates to the construction and organization of apparatus for producing
reciprocating movements by means of electricity.
The object of the invention is to provide a reciprocating engine or machine, such
for instanco as is used for operating a rock drill, which can be actuated in the required
manner by means of electric currents. in which the engine shall be simple in its con-
struction, requiring in itself no movable contacts, commutator, or other apparatus
liable to get out of order.
The invention will be described in detail in connection with the accompanying
drawing, which is a diagram showing an end view of the generator and a section of
the reciprocating tool.
This
Referring to the Figure, A represents a generator for electric currents.
generator here represented consists of a field inagnet F provided with two poles F¹
and F. The field magnet is energized by means of currents from any suitable
source O, connected through the field magnet coils F³, by means of conductors 1
and 2. This produces opposite polarities in the two poles F and F2. The armature B
It is here
is carried upon a shaft band is driven in any suitable well known manner.
shown with one coil only wound, after the manner of a Siemens shuttle-wound
armature. Other types of armature may, however, be adopted, as found convenient.
The respective terminals of the coils Care connected with contact plates d¹ and d².
The former of these is a continuous ring carried upon the shaft and is provided with
a brush E. The latter contact-plate, d, occupies a portion only of the periphery of
the commutator. In this instance it is shown in the form of a semi-circle, but the
length may be varied as required in a manner that will hereafter appear. This plate
is provided with two brushes E' and E2 and they are at an angle of 180 degrees with
each other, so that the plate leaves one brush as it comes into connection with the
other. It will be evident, therefore, that if the brushes E' and E' be connected with
the brush E by different conductors, currents will be transmitted through these con-
ductors altérnately.
The reciprocating tool consists of a core H movable to and fro within two
solenoids Hand H. These are placed end to end and carried in any suitable
frame or support K. The core is provided with an extension h adapted to carry
a rock-drill or a rod connecting therewith, or any suitable instrument according to
the purpose to which the invention is to be applied. A buffer or recoil spring M
may be applied to the core for the purpose of receiving the blow upon its reverse
movement. As here shown it is carried in a head M' but the precise construction
is not material. The brush E' is connected by a conductor 3 through the coil H¹
to a binding post N. The brush E' is connected by a conductor 4 through the
coil H to the same binding post N, and the conductor 5 leads from this binding
post to the brush E. The direction of winding of the coils and the connections
with the generator are preferably such that the direction of polarization of the core
will always be the same.

page_text: It will be evident that as the armature of the generator is revolved, currents
will be transmitted alternately through the solenoids H and H2 and these will drive
the core or armature H to and fro with a rapidity dependent upon the rate of
movement of the armature. If the plate d' occupy one half the periphery of the
commutator as shown in the drawing, then the reverse movement will cominence
immediately upon the cessation of the forward movement and the core will make a
complete reciprocation for each revolution of the armature, but by varying the
length of this plate, the blows may be made more intermittent-that is, separated
by any desired interval-and, in general, the organization of this plate and the
brushes applied thereto may be modified as found convenient for special purposes.
A circuit-closer or switch P may be included in the conductor for controlling the
circuit-connections.
It is evident, that where the invention is applied to a rock-drill, for instance, the
instrument may be placed at any desired distance from the generator as it is necessary
only to lead three conductors therefrom, and as the construction of the instrument
itself is very simple there is nothing to become out of order and it does not require
skilled labour to control and operate the device.
The invention is not confined to use in connection with a rock-drill, but it may be
employed for various other devices where reciprocating movements are desired.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. A source of electric currents consisting of a field magnet and an armature
revolving in the field of said magnet, a collector with which one terminal of the
armature coils is connected, a brush at all times in contact with said collector, a second
collector in connection with the other terminal of the coils, and two contact brushes
alternately making contact with said second collector, each of said brushes connected
to an independent circuit, substantially as described.
2. A source of electric currents, consisting of a field-magnet and an armature
revolving in the field of force of said magnet, a collector with which one terminal of
the armature coils is connected, a contact-brush at all times in contact with said
collector, a second collector in connection with the other terminal of the coils, two
contact brushes alternately making contact with said collector, conductors leading
from the latter brushes respectively, and two solenoids or electromagnets respectively
connected in said conductors, and a conductor leading therefrom to the first-named
contact brush.
Dated this 17th day of June 1889.
WM. P. THOMPSON & Co.,
Agents for the Applicant.