Improvements in Percussion Drills and other Percussion Tools.
Year: 1894

page_text: Date of Application, 11th Jan., 1894
Complete Specification Left, 11th Oct., 1894-Accepted, 17th Nov., 1894
PROVISIONAL SPECIFICATION.
[Communicated from abroad. by Messrs. SIEMENS & HALSKE, of Berlin, in the
German Empire, Electrical Engineers.]
Improvements in Percussion Drills and other Percussion Tools.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate, in the
City of Westminster, Electrical Engineers, do hereby declare the nature of this
invention to be as follows:-
This invention has reference to the construction of percussion drills and other
percussion tools such as was described in the Specification to Patent No. 14794
of 1891 wherein the percussive reciprocating motion was imparted to the bar
holding the drill or other tool by means of a revolving crank that was connected
to the drill bar by means of two springs serving as elastic connecting rods whereby
the motion of the crank was imparted to the drill bar in an elastic manner so
as to produce the requisite percussive action.
According to the present improvements, instead of connecting the revolving
crank to the one end of each of the springs, the other ends being connected to
the drill bar as described in the said Specification, the crank pin works in a
slotted part of a sliding frame surrounding the drill bar and the two springs
have their one end bearing against an abutment on the drill bar while the other
end is made to bear against an abutment on the sliding frame. By this means
a more compact and rigid arrangement of the machine, as also a better guide
for the springs in their expanding and contracting motion is obtained.
With this arrangement, either the outer ends of the springs are made to abutt
against the sliding frame, and the inner ends against a collar on a sleeve held
rotatably on the drill bar by screw collars or otherwise, or the outer ends may
bear against rollers on the drill bar and the inner ends against abutments on the
sliding frame; in either case the reciprocating motion imparted to the sliding
frame by the crank, is transmitted through the springs to the drill bar.
In applying the above described construction to a percussion rock drill, the
arrangement is by preference as follows.
The sliding carriage of the machine within which works the reciprocating frame,
being carried at one side in a guide piece pivotted to an adjustable sleeve on an
upright standard, the opposite side of the carriage is formed with the necessary
guide ribs or grooves for the sliding frame to work upon, so that by this means
the drill bar is brought as near as possible to the pivotting support on the
standard. The sliding frame consists firstly of a longitudinal plate working on
the before mentioned guides on the carriage and having at one end the slot for
the crank to work in, and secondly, of two end plates or discs through which the
drill bar passes, and which are tied together and to the plate by two opposite
longitudinal tie bolts.
These plates serve for the abutments of the outer ends of the springs which
are of helical form surrounding the drill bar, their inner ends being made to
abut on the collar of the before mentioned sleeve held between collars on the
drill bar, and having two lateral eyes embracing loosely the above mentioned
tie bolts.
The usual periodical rotation of the drill bar in one direction is effected by
forming a series of helical grooves or threads of very quick pitch on the outer

page_text: surface of the drill bar at the rear part thereof, which works backwards and
forwards through a correspondingly threaded disc held by the sliding carriage in
such manner that when the drill bar slides through the disc in one direction the
disc is held stationary by a ratchet device so that the drill bar is made to revolve,
while when it slides in the contrary direction the disc is free to revolve so that
the drill bar is not turned back again thereby.
The sliding carriage is formed with stuffing boxes at each end serving as guides
for the drill bar to work through.
The forward feed of the carriage as the boring advances is effected in the
usual manner by a screw spindle worked either by hand or by known automatic
devices.
The rotation of the driving crank is by preference effected by bevil gear from
a shaft driven by an electric or other motor engine separate from the drill.
Dated this 11th day of January 1894.
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Percussion Drills and other Percussion Tools.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate, in the
City of Westminster, Electrical Engineers, 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 has reference to the construction of percussion drills and other
percussion tools such as was described in the Specification to Patent No. 14794 of
1891 wherein the percussive reciprocating motion was imparted to the bar holding
the drill or other tool by means of a revolving crank that was connected to the
drill bar by means of two springs serving as elastic connecting rods whereby the
motion of the crank was imparted to the drill bar in an elastic manner so as to
produce the requisite percussive action.
According to the present improvements, instead of connecting the revolving
crank to the one end of each of the springs, the other ends being connected to the
drill bar as described in the said Specification, the crank pin works in a slotted
part of a sliding frame surrounding the drill bar and the two springs have their
one end bearing against an abutment on the drill bar while the other end is made
to bear against an abutment on the sliding frame. By this means a more compact
and rigid arrangement of the machine, as also, a better guide for the springs in
their expanding and contracting motion is obtained.
With this arrangement, either the outer ends of the springs are made to abut
against the sliding frame, and the inner ends against a collar on a sleeve held
rotatably on the drill bar by screw collars or otherwise, or the outer ends may
bear against collars on the drill bar ard the inner ends against abutments on the
sliding frame, in either case the reciprocating motion imparted to the sliding frame
by the crank, is transmitted through the springs to the drill bar.
The accompanying drawing shews by way of example a percussion drill
constructed according to this invention in which the springs are arranged in the
manner first above described, namely with their outer ends bearing against the
sliding frame and their inner ends against the abutment on the drill bar.
Fig. 1 shews a longitudinal section, Fig. 2 a sectional plan and Figure 3 a cross
'section.
The sliding carriage A of the machine within which works the reciprocating
frame L is carried at one side in a guide piece B pivotted to an adjustable sleeve C
'on an upright standard C. The opposite or outer side of the carriage A is formed

page_text: with the necessary guide ribs or grooves such as A¹ for the sliding frame L to
work upon, so that by this means the drill bar P is brought as near as possible to
the pivotting support on the standard. The sliding frame consists firstly of a
longitudinal frame L working on the before mentioned guides on the carriage and
having at one end the head piece L' and the slot L' for the pin of the crank K to
work in, secondly, of the end plate or discs e through which and through a hole
in L' the drill bar passes, and thirdly of two opposite longitudinal tie bolts Z' Z'
that pass through lugs a¹ a³ on plate e, and as a on head L', and thus secure e
to L.
The lugs a¹ a³ a³ a work in longitudinal grooves A' of the carriage A, thus
affording additional guides to the motion of the sliding frame L. Against the
head Land plate e bear respectively the outer ends of the helical springs F¹ Fr
surrounding the bar P the inner ends of which springs bear against the abutment
flange g on the sleeve O which is secured in any suitable manner upon the drill
bar P such as between collars P1 P2 on the latter so as to allow the bar to rotate
in the sleeve.
The sleeve O has two lugs a' a' which slide upon the tie bolts Z' Z' within the
grooves A³ so as to prevent the sleeve from turning with the drill bar.
The crank shaft K being driven by any suitable mechanism such as by bevil
gear and flexible shaft W from a separate motor such as described in the Specifi-
cation to Application No. 24083 of 1893, the crank pin imparts a reciprocating
motion to the sliding frame L which transmits such motion in an elastic manner to
the drill bar P through the helical springs F1 F2, and abutment g, the spring F
being put in compression for effecting the forward stroke while the spring is put
in compression for the backward stroke.
The springs are fitted into the frame L with a slight initial compression, so that
when the one is compressed with the maximum load, the other shall still exercise a
slight strain.
The usual step by step rotation of the drill bar may be effected in any known
manner, such as by forming quick screw threads on the bar, working through a
nut Y with pawl and ratchet motion carried by the carriage A.
The drill bar P is guided in necks E' E' at the ends of the carriage A, the
neck E being provided with a stuffing box for preventing the entrance of grit.
The forward feed of the drill carriage, as the drilling proceeds, is effected by a
3 feed screw D rotated either by hand as shewn or by any suitable known automatic
gear to be placed in the enlargement A' of the carriage A and worked by toothed
gear on the drill bar P.
The crank shaft K is provided with a fly wheel S for equalising the motion.
Although we have described the invention as applied to percussion drills, it will
> be readily understood that it is equally applicable to other percussive tools such as
stamps and hammers.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In percussion drills and other percussion tools, imparting the to and fro
motion to the bar carrying the tool by means of a revolving crank actuating a
sliding frame which is connected to the said bar through two opposite springs so
arranged as to transmit the motion of the frame to the bar in an elastic manner,
substantially as described.
2. In percussion drills and other percussion tools, mechanism for imparting
reciprocating motion to the tool, consisting of the combination of a sliding frame
such as L, receiving a to and fro motion within a carriage from a crank motion,
and helical springs such as F' F' surrounding the tool bar and having their one
end connected to the tool bar and their other end connected to the sliding frame L,
5 substantially as described.

page_text: 3. In driving mechanism for percussion tools such as is referred to in the
preceding claims, arranging the sliding frame L to work in guides on the outer
side of the carriage A so as to bring the tool bar as close as possible to the
connection of the carriage with its support, substantially as described.
Dated this 11th day of October 1894.
ABEL & IMRAY,
Agents for Applicants.