IMPROVEMENTS IN DIRECT-ACTING ENGINES AND DRILLING APPARATUS, THE SAME BEING APPLI- CABLE TO DENTAL TOOLS, ROCK AND OTHER DRILLS
Year: 1879

page_text: LETTERS PATENT to Henry Richmann and Uriah Kline Arnold, of San Fran-
cisco, California, U.S.A., Gentlemen, for the Invention of "IMPROVEMENTS IN
DIRECT-ACTING ENGINES AND DRILLING APPARATUS, THE SAME BEING APPLI-
CABLE TO DENTAL TOOLS, ROCK AND OTHER DRILLS."
Sealed the 7th March 1879, and dated the 10th January 1879.
COMPLETE SPECIFICATION filed by the said Henry Richmann and Uriah
Kline Arnold at the Office of the Commissioners of Patents on the 10th
January 1879.
HENRY RICHMANN and URIAH KLINE ARNOLD, of San Francisco, California,
U.S.A., Gentlemen. "IMPROVEMENTS IN DIRECT-ACTING ENGINES AND DRILLING
APPARATUS, THE SAME BEING APPLICABLE TO DENTAL TOOLS, ROCK AND OTHER
DRILLS."
Our Invention relates to certain improvements in that class of apparatus known
as direct-acting engines and drilling apparatus, in which the drill is actuated
directly from a piston moving in a cylinder, and driven preferably by compressed
air, which is brought to the cylinder through a flexible or other suitable tube.
This apparatus may be employed for a rock drill or for a dental engine, and for
other similar uses. When used for either of these purposes we employ a piston
moving axially within a cylinder, said piston containing a valve which is concentric
with itself, and has a reciprocating movement in the same direction with the
piston. Suitable ports are formed within the cylinder and the piston to afford
ingreas and egress to the air, which is employed as a motor. In combination with
this peculiar piston and valve we employ a stem or spindle which may hold the
operating tool, and is actuated by the movement of the piston. When employed as
a dental engine, a pin passing through the stem, and a transverse alot in the case,
serves to limit the movement of the tool; when employed for a rock drill, the
cylinder is mounted and guided within a trough, which is in turn supported upon a
tripod, said tripod being provided with a novel means for mounting and adjusting
the parts upon it.
An improved means for regulating the rotation of the drill is embodied as a
portion of our Invention, together with certain details of construction which will be
more fully described by refering to the accompanying Drawings, in which,
-
Fig. 1 is an exterior view of our apparatus as applied for use in a rock drill,
with its tripod and adjusting mechanism.
Fig. 2 is a section taken through the axis of the cylinder.
Figs. 3, 4, 5, and 6 are detailed views of parts of the machine,

page_text: Fig. 7 is an exterior view of our apparatus as applied to a dental engine; Fig. 8
is a section of the same taken through the axis.
In describing our Invention we shall first refer to its employment for a rock drill,
in which A represents the slotted cylindrical trough or carriage in which the
cylinder and operating mechanism of the drill is supported, said carriage having
trunnions which are journaled in the tripod stand as shown. In the trough or
carriago is fitted a slotted cylindrical case B, which carries the cylinder C, said case
having a removable head D arranged so that the head may be screwed on after the
cylinder is in position.
At each end of the trough or carriage is a lug E, in which rotates the feed screw F,
operated by the hand wheel G, and said feed screw passes through an internally-
threaded leg or carrier H attached to the sliding case B, as shown. By rotating the
hand wheel the feed screw slides the case B, carrying the cylinder and drill up or
down in the carriage, thus giving any desired feed to the drill. By this construction
the cylinder is free to revolve in the case, so as to get a proper rotation to the drill,
as herein-after described, while at the same time the drill may be fed forward or
withdrawn from the hole.
The cylinder C has a neck or extension I, which may project up through a central
bole in the upper head J of the case B; at the upper end of this neck I is the
coupling K for the hose which furnishes compressed air or steam to the cylinder,
and the stuffing-box L serves to keep a tight joint at this point. The hose connec-
tion is made so as to remain stationary as the cylinder rotates.
A novel feature of our device is in the construction of the operating piston
having its controlling valve situated within itself, and moving in the same direction
with the piston, and this enables us to obtain a very high rate of speed. The
piston U moves in the cylinder C, and the stem or spindle V extends out through
one end, and has the drill secured to it.
The case or cylinder C has an extension or neck I, through which an inlet
passage e is formed, this passage extending around to one side as shown. Connec-
tion is made with this extension V by means of a flexible pipe and a swivelling
joint or coupling K, which will allow the cylinder and drill to turn independently;
as has been previously described. Upon the side opposite to the inlet e are the
outlet passages i, n, for the cylinder and the valvo chamber respectively. The
piston is provided with inlet and discharge passages, both for its own propulsion
and for that of its contained valve; the valve g has two heads and a central pro-
jecting flange which fits the chamber within which it moves, and between the
central flange and the heads is a smaller connecting portion m, m', on each side, as
shown, which has a sufficient space around it to allow air to pass from one port to
another when exposed. The action will then be as follows: The piston being at
one end of its cylinder, and the valve being at the same end of its chamber, a
passage h, which extends from the exterior of the piston to the valve chamber, will
open into the inlete and the space surrounding the part m'. A passage o' is made
within the body of the piston, which extends from this space in the valve chamber
to one end of the piston, as shown. The air, gas, or vapor employed will then pass
from the inlet e through the passage h, around the stem m', and through the
passage o' into the cylinder, where it acts to drive the piston forward to the
opposite end of the cylinder. When the piston has started, and moved a short
distance, it will expose a port a, so that connection will be made between the inlet
passage e and the end of the valve chamber. This allows the valve to be driven
rapidly to the opposite end of the chamber, and the central flange of the valve will
thus pass the passage h, so that communication will be opened into the space
surrounding the port m, and thence through the passage o to return the piston.
The passage a' will admit air in the manner before described to return the valve.
The air is allowed to exhaust by means of passages S', which communicate with
the spaces m, m³, around the valve, and when the pistou moves toward either end
of the cylinder, the passage o or o' from that end will communicate through S¹ with
the exhaust passage i. The valve is similarly relieved by ports r which connect

page_text: with small ports n opening into the exhaust when the valve is ready for its return
stroke.
The lower cylinder head M is made removable, and has a threaded offset N, by
means of which it is screwed in place, the lower internal portion of the cylinder
head being provided with threads for this purpose. On the lower or outer part of
this cylinder head M is formed a cylindrical projection or neck O, having two or
more straight slots P for part of its length, for the purpose herein-after described.
Over the neck or projection O slips the cylindrical sleeve Q, having two or more
curved slots R, for the purpose herein-after described. At the upper end of the
sleeve Q, and encircling it, is the ratchet wheel S, arranged so that when in place
the pawl T, on the inside of the lower head of the case B in which the cylinder is
placed, will engage with said ratchet wheel, so as to revolve the drill, as is more
fully described herein-after.
The piston U and piston rod or stein V are all in one piece, and the lower end of
the piston rod is cut away somewhat smaller than the rest of the rod, and has screw
threads formed on it as shown at W. It is also hollowed out at the lower end, and
has screw threads formed on its inner surface for the drill clamp to screw into, as
herein-after described.
After the piston is in place in the cylinder, and the cylinder head screwed on, the
piston rod projects down into and through the slotted neck or projection O. The
cylindrical sleeve Q, having the curved slots in it, is slipped over the neck or
projection O, so that the ratchet wheel comes close up to the cylinder head, as
shown.
A small collar or sleeve X, with screw threads on its inner surface, and two or
more lugs Y projecting from its sides, is screwed on to the threaded portion W of
the piston rod. It then remains between the outer part of the piston rod and inner
part of the projection or neck O, the lugs however projecting through the straight
slots P in the neck O, and through the curved slots R in the sleeve Q. A key Z is
then placed in the key seats cut in the inner side of the collar X and the outside of
the lower end of the piston rod, so that the collar X is keyed to the piston rod, and
thus kept from turning.
The clamp A' by which the drill rod is secured to the piston rod has screw threads
formed on its outer edge, and its lower end formed with a shoulder.
This clamp
is split lengthwise, and is made with slight taper as shown, so that when screwed
into the internally threaded lower end of the piston rod herein-before described the
parts are sprung together so as to grip the drill head closely. By unscrewing it the
drill is quickly and easily released.
In working rock drills it is necessary that the position of the cutting edges of the
tool shall be changed at each blow of the drill, and to accomplish this the drill must
be inore or less rotated, according to the nature of the rock. In our inproved drill
this rotary motion is accomplished by means of the mechanism herein described,
and the amount of rotation may be regulated at will.
When the cylinder C is in position in the casing B the lower head of the case B
is screwed on, thus confining the cylinder in the case as before described. One or
more spring pawls T are secured to a flange on the inner part of the head D of the
caso B, and when this head is screwed in place the pawl or pawls are in position to
engage with the ratchet band S on the slotted sleeve Q. This sleeve Q has slots
cut in it which are made curved and with an increasing twist, while the slots P in
the neck or projection O over which the sleeve Q is slipped are cut straight. The
lugs Y on the collar X correspond in number to the slots in the neck O and sleeve Q,
and project into said slots, the collar carrying the lugs being screwed on to the
lower threaded end of the piston rod and keyed to said rod so as to be prevented
from revolving except with said piston rod. The piston rod, however, cannot
revolve independently, since the lugs on the collar X project into the straight slots
in the neck O of the cylinder head. The cylinder itself, while confined in the case B,
is free to revolve.

page_text: The spring pawls which operate the ratchet S on the sleeve Q are, as described,
on the inner side of the head of the case B, and said case is kept from revolving by
the feed screw passing through the lug in its side.
As the reciprocating motion is given to the piston and piston rod by the valve
motion herein described, when the piston rod goes forward it carries with it the
collar X, the lugs on said collar being free to move forward and back in the straight
slots in the neck of the cylinder. As the rod comes back, however, the lugs impinge
on the sides of the curved slots R in the sleeve Q, and as this sleeve is held stationary
by the pawl T in the head of the case B engaging with the ratchets on the upper
end of the sleeve Q, the effect is to turn the cylinder slightly in the case so that the
cutting edge of the tool clamped to the piston rod is presented in a new position in
the drill hole. Then as the piston is forced forward again the pawls allow the
sleeve Q to revolve slightly ready for a new hold.
The amount of rotation to the drill depends on the position of the lugs on the
collar with relation to the curved slots in the sleeve Q. These slots have a gradually
increasing twist as shown. The collar may be screwed up or down on the lower
end W of the piston rod so as to bring the lugs on said collar at any desired point
in the slots. This is done by removing the key or screw holding the collar to the
piston rod; then by removing the case head and cylinder head and giving one or
more turns to the piston and piston rod by hand, the collar is screwed up or down
the piston rod until it reaches the desired point with relation to the curved slots on
the sleeve, and as the lugs on the collar rotate the cylinder in proportion to the
curve in the slots as the lugs are brought up to a point of greater curve of the slots,
more rotation is given to the drill point. The key or screw is then put in place
and the collar secured to the piston rod as before. By thus varying the position of
the collar and lugs in relation to the increasingly curved slots on the sleeve, more or
less rotation is given to the drill as desired.
The tripod stand B' is formed in two parts, the parts being joined together by
screws passing through the flauges or clamps C and D', the same screws or bolts
joining the legs forming the tripod to the tripod stand.
The lugs Care divided into two parts as shown, and have circular slots in them
to form journals for the trunnions of the trough or carriage A.
The legs E' have screw threads formed on them at their upper ends, and internally
threaded sleeves F' screw on to legs so that the height and position of the drill may
be regulated. These sleeves are pointed at their lower ends to prevent slipping on
the ground, and have lugs G¹ on which weights may be hung so as to steady tho
drill. A lock nut H' screws on to the legs above the sleeve, so that when the sleeve
is turned to the proper position, by screwing this nut down against it tho slcevo is
provented from moving by the jar when the drill is running.
The upper end or head I' of each leg is enlarged and divided or slotted, as shown,
to form a clamp so that the two parts clasp the lugs on the tripod stand. Then by
passing a screw or bolt transversely through both head of leg and lug the legs are
firmly clamped to the tripod stand, the same bolt or screw serving to clamp the
parts of the tripod stand together.
By our method of construction we avoid all angular projections and exterior
valve chambers. All parts of our drill and valve are cylindrical and made from a
common center, and this enables us to make the whole of steel and of the lightest
and strongest construction. It is also easy to set up or take apart.
By our construction of the piston containing its own operating valve moving in
the same direction with itself and a short stroke, we are enabled to obtain a high
rate of speed and strike a greater number of blows than has heretofore been
accomplished.
The adjustable rotary feed enables us to employ the drill to the best advantage in
both hard and soft rock.
In Figs. 7 and 8, which show the application of our Invention to a dental tool,
A is an outer case or cylinder, within which the piston B* reciprocates; and C is

page_text: an extension screwed to the case A', and within which the spindle or stem D' moves.
The case or cylinder A* has an extension or tube E at one end which is hollow and
is fitted to receive a flexible air-conveying pipe. A passage F connects with the
hollow extension and passes along one side of the cylinder so as to connect with
the supply ports, as will be herein-after described. Upon the opposite side of the
cylinder are the exhaust ports which are suitably placed to dischargo the air.
The piston B' fits into the cylinder, and is made hollow in the direction of its
length. Within this hollow piston is placed a valve G. This valve has a head at
each end, and a central flange which fit closely, while between these points are
portions which are turned smaller as shown.
The port H which opens through the side of the piston near its center allows the
air to enter it and surround the valve. When the valve is at one end of its stroko
this port will communicate with the space a³, and when it is at the opposite end of
the stroke it will communicate with the space a³. Two passages c³, c³, are made
within the body of the piston, one extending out at one end and opening into the
space a which surrounds the valve, while the other connects the space a with the
opposite end of the piston chamber.
C
It will be evident that when the valve is in the position which allows the
passage H+ to communicate with the space a* the air will rush through the passage
and into the cylinder behind the piston, so as to drive the piston to the opposito
end of the cylinder. During this movement a port I, which opens through the
side of the piston and into the valve chamber behind the valve, is opened by being
brought opposite a supply port J' in the cylinder. This allows the air to rush in
and drive the valve to the end of its chamber, moving in the same direction with
the piston.
The exhaust passages K and L* at each end connect respectively with the ends
of the valve chamber and the cylinder, and open through ports M* and N*, so that
when the piston and valve start upon their return stroke the air at the opposite
ends of each will be allowed to escape.
The air for the return stroke is admitted to the space a³ and passage c³ from
the port H by the movement of the valve, which carries the central flange past
the port.
By this construction we provide an extreemly effective motor. The piston and
valve moving in the same direction do not retard the action of each other, and we
are enabled to attain a very high rate of speed. This piston acts as a mallet, and
strikes the head O of the independent stem or tool holder P³, which is situated
within the lower part or guide Q' of the tool. This head is enlarged, and a
chamber just below it receives a spring R', which serves to return the stem after
each stroke. The spring R' is made of rubber or other elastic material, and fits around
the reduced portion of the stem beneath the head, so as to not only return the stem
after the stroke but also to serve as a packing to prevent the escape of air from the
cylinder. This feature renders the action much more effective, and the speed can bo
considerably increased on account of non-leakage.
A slot S is made through the guide Q', and a pin T' passing transversely
through the stem extends out into this slot, so that it only allows the stem to move
the length of this slot. This prevents the piston from being bruised by striking
the ends of the cylinder, and avoids the necessity of special cushioning devices. Wo
have adapted this principle of direct-acting piston and contained valve to the rock-
drilling apparatus which has been heretoforo described.
We are aware that dental tools have been constructed having a piston which
reciprocates longitudinally within a cylinder, and a valve which moves transversely
within the said piston; but this is objectionable on account of the number of ports,
difficulty of construction, and the constant striking of the ends of the valve against
the sides of the cylinder.
We do not claim broadly a piston containing its controlling valve for dental
tools, but we claim our mechanism substantially as shown and described.
Having thus described and set forth our Invention wo enumerate in the following

page_text: .claims the essential features which we desire to claim and secure by Letters
Patent, viz.:-
1st. The screw-threaded tripod legs El and the adjusting threaded sleeves F¹
receiving the legs E¹ into their upper ends, said sleeves having their lower ends
pointed to rest upon the ground together with the lock nuts H', to secure the
adjustment, substantially as herein described.
2nd. The clamps C₁ fitted to receive the trunnions and having a slotted
extension, which fits into the head I¹ of the legs of the tripod; said head being
provided with a single screw, by which the clamps are secured to the legs and to
the trunnions at one operation, substantially as herein described.
3rd. The case B, fitted to receive and support the independently rotating driving
cylinder C; said case having the threaded aleeve or nut H secured to one side to
receive the screw F, which is journaled upon the trough or carriage A, so that the
case and cylinder may be moved forward and back without reference to the action
of the cylinder or piston, substantially as herein described.
4th. The cylinder receiving and holding caso B, with its removable head D pro-
vided with the pawl T, together with the cylinder C, sleeve Q, having the curved
slots R, as shown, and the ratchet S, substantially as herein described.
5th. The tapering slotted clamping screw A', which is formed to receive the drill
and to hold it by being screwed into the end of the piston rod, of which it then
forms a part, substantially as herein described.
6th. The piston, with its extension W, fitted to receive the drill clamp A', and
having screw threads cut upon the outsido, so that the collar X may be screwed up
or down upon it to adjust the position of the lugs upon said collar with referenco
to the curved slots in the sleeve and the holding key Z, substantially as herein
described.
7th. The extension O of the cylinder with its straight slots P, together with the
sleeve with its curved slots R, and the collar X with its lugs Y, whereby the
drill is rotated while being reciprocated, substantially as herein described.
8th. The extension O with its straight slot, and the sleeve with its slots R,
formed with an increasing curve, together with the adjusting collar X with its
actuating lugs Y, whereby the amount of rotation may be regulated and adjusted
substantially as herein described.
9th. The cylinder C with its piston U, provided with the ingress and egress
ports, as shown, and the valve g, working concentrically within the piston and in
the same direction, substantially as and for the purpose herein described.
10th. The piston U, with its contained actuating valve reciprocating within the
cylinder C, said piston being provided with ports h, a, o, whereby both piston and
valve are caused to move in the same direction, substantially as herein described.
11th. The improvement in reciprocating drilling apparatus, consisting in forming
the valve within the piston and concentrically with the cylinder, enclosing case,
and guide or trough, whereby the drill forming an extension of the piston rod is
rotated with the cylinder within its case, substantially as herein described.
12th. The cylinder or case A*, with its axially moving hollow piston B' in com-
bination with the valve G, moving within the piston and in the same direction
with it and the supply and exhaust port, substantially as and for the purpose
herein described.
13th. The improvement in dental engines or mallets, consisting in the hollow
piston or mallet B* moving axially within the case A* and containing the con-
trolling valve G, which moves in the same direction with the piston, together with
the ports H, valve surrounding spaces a³, a³, and the passages c², c³, and exhaust
ports K*, L*, substantially as and for the purpose herein described.
14th. The hollow piston or mallet B, moving within the cylinder A* and con-
taining the valve G*, moving in the same direction with the piston in combination
with the stem P, with its head O' and the spring R', substantially as hercin
described.
15th. The hollow piston or mallet B*, moving longitudinally within the case A*

page_text: and provided with the longitudinally moving valve G', as shown in combination
with the stem P with its transverse pin T and the slotted guide Q', substantially
as and for the purpose herein described.
16th. In a dental engine we claim the piston or mallet B* moving within the
cylinder A, so as to give successive blows upon the head of the stem P³, in com-
bination with the elastic spring and air-tight packing K', to return the stem after
a stroke and prevent leakage from the cylinder, substantially as herein described.
In witness whereof, we, the said Henry Richmann and Uriah Kline Arnold,
have hereunto set our hands and seals, this Twenty-second day of November,
in the year of our Lord One thousand eight hundred and seventy-eight.
HENRY RICHMANN.
(LS.)
Witnesses,
GEO. H. STRONG,
FRANK A. BROOKS.
URIAH KLINE ARNOLD. (La)