Improvements in Electric Drills or Reciprocating Motors, and in Dynamos for Working the same.
Year: 1894

page_text: Date of Application, 3rd Jan., 1894
Complete Specification Left, 2nd Oct., 1894-Accepted, 29th Dec.. 1894
PROVISIONAL SPECIFICATION.
Improvements in Electric Drills or Reciprocating Motors, and in
Dynamos for Working the same.
I, NATHANIEL SHEPARD KEITH of 711 Jones Street, in the City and County
of San Francisco, State of California, United States of America Electrical
Engineer do hereby declare the nature of the said invention to be as follows:-
This invention relates to drills or reciprocating motors which are caused to
reciprocate by two solenoids through which electric current is alternately passed.
In such drills great difficulty has heretofore been caused by the heating of the
solenoids which has rendered continuous working impossible and although various
expedients have been resorted to with a view of overcoming this difficulty none of
them have been wholly successful.
According to this invention I keep the solenoids cool by making their coils of
hollow wire and passing water or other fluid through it. The wires and the holes
through them may be of circular square or other section and the area of the holes
may be diminished by passing a wire or wires through them.
I also add greatly to the efficiency and endurance of such drills by various
improvements in their construction.
The tool or steel drill is carried by a cylinder of iron, slotted longitudinally.
This iron cylinder has an extension fastened on one end of it, of non-magnetic
metal, such as brass, bronze, or the like, for the purpose of holding the steel drill.
The other end of the cylinder is made smaller in diameter so as to slide within a
ratchet nut. It also has one or more spiral grooves, in this end, which fit corre-
sponding spiral projections on the internal wall of the ratchet nut. The ratchet
nut is held by pawls so that it can only revolve in one direction and when the
cylinder is caused to reciprocate rapidly its engagement with the ratchet-nut causes
it to rotate when the drill is being withdrawn.
The ratchet-nut is made of brass, bronze, or some suitable non-magnetic
material.
The cylinder is when in action caused by magnetic attraction to reciprocate in
a case which is a longitudinally slotted tube made of brass or like non-magnetic
material; it acts as a guide and support for the cylinder. The ends of the tube
are received in recesses in two annular collars of iron, and a third annular radially
slotted collar is placed upon the tube midway between the other two. The latter
are made larger in diameter than the central one so that they may be bound
against the ends of an outer iron, tubular, cylindrical case, by bolts external to the
case, and passing through both of them, the central collar fitting inside the case.
In this way there are formed two annular spaces, in which are placed the solenoidal
coils which may be made to fill the spaces, if desired.
The conductors of these coils, are tubular, as above described.
There is a cap fastened on one end of the apparatus. In this cap are the pawls
for restraining the motion of the ratchet nut and also a piston, and air-valve.
This piston and air-valve with the cap form an air-spring which receives the
impact of the cylinder when it moves that way. The object of the valve is to
allow of the admission of air to replace that which leaks by the piston.
The pawls are put in recesses in the cap and are caused to press against the
ratchet-teeth, of the ratchet nut by small spiral compression springs.

page_text: In order that the electric current may be alternately passed through the two
solenoids I modify the dynamo as follows:-
On the shaft of any direct current dynamo I fasten two rings of electric
conducting material concentric with the shaft, but insulated therefrom and from
each other, except through the coils of the armature of the dynamo as hereinafter
stated. From two diametrically opposite points of the armature I electrically
connect the coils of the armature with the rings, one connection with each ring.
To one ring I apply a metal spring or brush which is electrically connected with
one end of each of the two solenoids of the reciprocating drill or motor. To the
other ring I fasten, tangentially or otherwise, a conducting spring or brush, which
is caused to impinge at its outer end upon the inner surface of a separately
supported and concentrically placed ring. This ring is, in its body, of non-
conducting material, but it carries on its inner surface two segments of conducting
metal, insulated from each other, and so placed that when rotated the brush bears
upon them in succession each during nearly one half of the rotation of the brush.
These two segments are electrically connected to the other ends of the wires of
the solenoids. One segment to each solenoid. I provide that this ring may be
rotatable in its support so that it may be placed and fastened at the point where
the brush may pass from segment to segment with the least sparking.
With this apparatus clectric current is passed through the solenoids, each
successively.
In cases where there is not sufficient natural, or otherwise obtainable, pressure
on the fluid used to pass through the hollow wires of the solenoids, I provide a
pump for such liquids as an attachment, and accessory, to the drill or reciprocating
motor. This pump I cause to operate by suitably connecting it through a tube
with the interior of the rear end of the drill case. Part or all of the air which
is sucked in and expelled at the rear end of the drill case, by the reciprocation of
the cylinder, causes the operation of the pump.
Dated this 2nd 1.
1000
Improvements in Electric Drills or Reciprocating Motors, and in
Dynamos for Working the same.
I, NATHANIEL Shepard Keith of 711 Jones Street, in the City and County
of San Francisco, State of California, 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 :-
This invention relates to drills or reciprocating motors which are caused to
reciprocate by two solenoids through which electric current is alternately passed.
In such drills great difficulty has heretofore been caused by the heating of the
solenoids which has rendered continuous working impossible and although various
expedients have been resorted to with a view of overcoming this difficulty none of
them have been wholly successful.
According to this invention I keep the solenoids cool by making their coils of
hollow wire and passing water or other fluid through it. The wires and the holes
through them may be of circular square or other section and the area of the holes
may be diminished by passing a wire or wires through them.
Such wires are shewn in section to an enlarged scale at Figures 1, 2 and 3, a being
the hollow wires and 6 (Figure 3) the internal wire.

page_text: I also add greatly to the efficiency and endurance of such drills by various
improvements in their construction.
Figure 4 shows the dynamo and drill the former being shown diagrammatically
and the latter in longitudinal section.
The tool or steel drill c is carried by a cylinder d of iron, slotted longitudinally
at d'. This iron cylinder has an extension d² fastened on one end of it, of non-
magnetic metal, such as brass, bronze, or the like for the purpose of holding the
steel drill c. The other end d³ of the cylinder is made smaller in diameter
so as to slide within a ratchet nut e shown with the cap in end elevation at
Figure 5. It also has one or more spiral grooves d' in this end, which fit
corresponding spiral projections e' on the internal wall of the ratchet nut. The
ratchet nut is held by pawls f' (not shown in Figure 4) in the cap so that it
can only revolve in one direction and when the cylinder d is caused to reciprocate
rapidly its engagement with the ratchet nut causes it to rotate when the drill is
being withdrawn.
The ratchet nut e is made of brass, bronze, or some suitable non-magnetic
material.
The cylinder is when in action caused by magnetic attraction to reciprocate in
a case which is a longitudinally slotted tube made of brass or like non-magnetic
material; it acts as a guide and support for the cylinder. The ends of the tube
are received in recesses in two annular collars of iron, and a third annular
radially slotted collar is placed upon the tube g midway between the other two.
The latter are made larger in diameter than the central one so that they may be
bound against the ends of an outer iron, tubular, cylindrical case k by bolts (not
shown) external to the case, and passing through both of them, the central
collar fitting inside the case. In this way there are formed two annular spaces,
in which are placed the solenoidal coils indicated in diagram which may be made
to fill the spaces, if desired.
k
Or the construction may be varied as shown in Figure 6 the case / being screwed
onto the collars h and the tube g into nuts g¹ held between the collars.
The conductors of the solenoid coils, are tubular, as above described.
There is a cap fastened on one end of the apparatus. In this cap are the
pawls for restraining the motion of the ratchet nut and also a piston m and air-
valve f³. This piston and air-valve with the cap form an air-spring which receives
the impact of the cylinder when it moves that way. The object of the valve is to
allow of the admission of air to replace that which leaks by the piston.
The pawls fare put in recesses in the cap and are caused to press against the
ratchet-teeth, of the ratchet nut e by small spiral compression springs f³.
In order that the electric current may be alternately passed through the two
solenoids I modify the dynamo as follows:-
On the shaft of any direct current dynamo I fasten two rings n n¹ of electric
conducting material concentric with the shaft, but insulated therefrom and from
each other, except through the coils o of the armature of the dynamo as hereinafter
stated. In practice these rings would be of the same diameter and placed side by
side instead of concentric with each other as shown. From two diametrically
opposite points p p¹ of the armature I electrically connect the coils of the armature
with the rings, one connection with each ring. To one ring n I apply a metal
spring or brush q which is electrically connected with one end of each of the two
solenoids of the reciprocating drill or motor. To the other ring I fasten,
tangentially or otherwise, a conducting spring or brush r which is caused to
impinge at its outer end upon the inner surface of a separately supported and
concentrically placed rings shown in elevation with one of its connections in
section at Figure 7. This ring is, in its body, of non-conducting material, but it
carries on its inner surface two segments s¹s of conducting metal, insulated from
each other, and from the rings and so place that when rotated the brush r bears
upon them in succession each during nearly one half of the rotation of the brush.
These two segments are electrically connected to the other ends of the wires of the

page_text: solenoids. One segment to each solenoid. I provide that this ring may be
rotatable in its support so that it may be placed and fastened at the point where
the brush may pass from segment to segment with the least sparking.
With this apparatus electric current is passed through the solenoids each
successively.
In cases where there is not sufficient natural or otherwise obtainable pressure on
the fluid used to pass through the hollow wires of the solenoids I provide a pump
shown separately at Figure 8 for such fluid as an attachment and accessory to the
drill or reciprocating motor. This pump I cause to operate by suitably connecting
it through a tube t with the interior of the rear end of the drill case between
m and d. Part or all of the air which is sucked in and expelled at the rear end
of the drill case, by the reciprocation of the cylinder, causes the operation of the
pump, which as shown has two cylinders ue the former connected to the pipe t and
having an opening a¹ at the other end and the latter having an inlet v' for air or
other fluid and an outlet v provided with a valve and connected by a pipe not
shown with one end of each of the hollow wires of the solenoids. In the cylinder
is a piston w whose rod is a plunger working in the cylinder v.
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 :-
1. Making the solenoid coils with hollow wires substantially as described.
2. Making the case of two concentric tubes clipped between the ends substan-
tially as described.
3. The cap with its loose piston and air valve substantially as described.
4. Causing the air compressed by the backward stroke of the drill to work a
pump for forcing fluid through the hollow wires of the solenoid coils substantially
as described.
5. The combined electric drill or reciprocating motor and dynamo substantially
as described and shown in the drawings.
Dated this 26th day of September 1894.