Improvements in Rock Drills and similar Machines.
Year: 1890

page_text: Date of Application, 15th May, 1890-Accepted, 26th July, 1350
Improvements in Rock Drills and similar Machines.
I CARL FRANKE of Breiter Weg 30 Eisleben in the Empire of Germany, Foreman,
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 motors designed principally to be operated by compressed
air or other motive fluid to give a percussive and rotary movement to a drilling tool
fitted thereon.
The improved motor is represented in the annexed drawing in which
Fig. 1 is a longitudinal section.
Figs. 2 3. 4. 5 and 6 are cross sections on lines A B, C, D, E F, G H, and I K
respectively of Fig. 1.
Figs. 7. 8 and 9 are side elevations of certain parts shown removed from the
motor.
Cis the cylinder of the motor, f the piston sliding therein and having formed or
fixed on it the hollow piston rod f. The piston f is made with an annular space
surrounding it, and in said space slides an annular slide valve 6 having outside around
its centre an annular flange or projection fitting accurately to the inside of the
cylinder Cand inside an annular recess forming a way or passage for the exhaust.
a is the compressed air inlet in the cylinder C, c is a passage leading through the
body of the piston from near the one end of the annular space around said piston to
the other end of the piston and d is a similar passage from near the one end of said
annular space to the other end of the piston opposite thereto. ee are passages
connecting the inner annular recess of the slide valve with the interior of the hollow
piston rod f, and f2 is an outlet from the interior of said piston rod finto the
outer air.
The compressed air passes into the working cylinder through the port a thence
through the channel c behind the piston fand pushes the latter forward simultaneously
with the slide valve, the used air in front of the piston passes through the channel a
underneath the slide valve and through the channel e¹ into the hollow piston rod f¹
from where it escapes into the open air through the opening f2.
As soon as during the forward motion of the piston f, the ring y on the slide valve b
covers the port a the inlet of compressed air is shut off and the piston works now with
expansion.
When the ring g has passed the port a the compressed air passes behind the ring g
of the slide valve and as now a diminution of pressure has taken place in the meantime
on the lefthand side of the ring by the expansion of the air the slide is thrown to the
left and the action of the piston reversed.
The back motion now takes place, the pressure air surrounding the slide valve
arriving at the front of the piston through the channel d whilst the previously used up
air escapes through the channel c below the slide b to the channel e and the hollow
piston rod. The slide 6 as soon as it has passed the port a is then thrown back again
towards the right into the position illustrated.
Rotary motion is given to the piston by the following arrangement.
Within the piston slides the bar with feather and groove h¹ which bar is turned
slightly at each stroke and turns the piston with it. The rotation of the bar i takes
place as follows. At the back of the cylinder C₁ is fastened a small cylinder k
preferably serewed into a continuation of the cylinder C. The cylinder k has two
oppositely located longitudinal slots terminating in the cross slots m m'at right
angles thereto (Figs. 6 and 8). In the cylinder k is the hollow piston n movable at a
short stroke. Said piston has two oppositely located oblique slots o o' and also two
pins p p which latter slide in the slots and prevent the hollow piston n from
Daine 621

page_text: rotating during its to and fro motion. On the bar i is revolvably arranged a disc q
which gears by means of two pins through the oblique slots o o' of the hollow
piston n and into the cross slots m m³ of the cylinder k on pins projecting across the
intervening space.
Between the disc g and the disc's' (which latter is revolvable likewise on the bar i)
are journalled the pawls tt, which gear into the ratchet wheel o secured on the bar i.
The bar i itself is journalled to revolve in the cylinder lid by means of a flange and is
kept in position by a nut c.
When the hollow piston n is moved forward and backward the disc g performs an
oscillating motion by the pins of the latter being forced alternately to the left and
right by the action of the oblique slots o o' and the cross slots m m'. This oscillating.
motion is given to the bar i and the piston f by means of the pawls t t' and the ratchet
wheel o so that the piston can rotate only in one direction. The to and fro motion of
the hollow piston
n is also operated by means of air pressure. When the latter pushes
the piston forward it drives also the hollow piston n backward travelling through the
channels y y whilst the air located behind n escapes through the channel and
through the channel d underneath the slide b. When on the contrary the
pressure air
pushes the piston back the former travels also through the channel z and pushes the
piston n forward.
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. In a motor the combination with the cylinder C¹ having the lateral inlet port a.
of the piston with contrary passages c and d therein and the annular slide valve b
adapted to slide in said piston and having the ring g thereon for the purpose set forth,
the hollow piston rod with outlet f2 and passages' c c¹ the whole substantially as
illustrated and described.
2. In a motor the combination, with the cylinder C and piston f sliding therein of
a shaft rotarily journalled in the cylinder head and tongued to said piston, a
cylinder having slots m m' in the wall thereof, a piston n inovable longitudinally in
said cylinder and having inclined slots o o' in the walls thereof, a disc q having
lugs r r engaging in said slots m o m¹ o¹ respectively, ratchet wheel o on said shaft i,
and a pawl or pawls on said disc q adapted to rotate said ratchet wheel for the
purpose set forth.
3. In a motor the combination of the cylinder C¹ the piston f sliding therein, the
shaft i rotarily journalled in one of the cylinder heads and tongued to said piston,
passages y in said cylinder head, the cylinder k fitted into an extension of the
cylinder C, a piston n sliding in said cylinder k and connected to rotate the shaft i
and a passage in said cylinders C and k the whole substantially as and for the
purpose set forth.
Dated this 15th day of May 1800
HERBERT & Co.;
18, Buckingham Street, Strand, London, W.C., Agents to Applicant.