MANCHON DE COUPLAGE DE CONNEXION D'UN BOULON FILETE A UNE MACHINE PERFORATRICE DE ROCHES A IMPACTS

COUPLING SLEEVE FOR CONNECTION OF A THREADED ROCK BOLT TO AN IMPACT ROCK DRILLING MACHINE

Abrégé français

L'invention concerne un manchon de couplage de connexion d'un boulon fileté (1) à une machine perforatrice (2) de roches à impacts, comprenant un premier élément (3) pourvu d'un filet interne (4) pour la connexion du boulon (1) et un second élément (5) pourvu d'un filet interne (6) pour la connexion de la machine perforatrice (2) de roches. Le second élément (5) comprend un dispositif (7) de verrouillage transversal par rapport à un axe longitudinal (9) sur le manchon de couplage, associé à une partie (8) de la machine perforatrice (2) de roches pour empêcher toute séparation du manchon de couplage et de la machine perforatrice (2) de roches.

Abrégé anglais

Coupling sleeve for connecting a threaded rock bolt (1) to an impact rock
drilling machine (2) comprising a first part (3) provided with an internal
thread (4) for connection of the rock bolt (1) and a second part (5) provided
with an internal thread (6) for connection of the rock drilling machine (2),
whereby the second part (5) comprises a transversely to a longitudinal axis
(9) on the coupling sleeve arranged locking device (7) which cooperates with a
region (8) on the rock drilling machine (2) for preventing that the coupling
sleeve and the rock drilling machine (2) are separated.

Revendications

CLAIMS:
1. A coupling sleeve for connecting a threaded rock bolt to an impact rock
drilling machine, said coupling sleeve comprising a first part provided with
an internal
thread for connection of the rock bolt, and a second part provided with an
internal
thread for connection of the rock drilling machine, wherein the second part
comprises
a locking device arranged substantially transversely to a longitudinal axis of
the
coupling sleeve, said locking device cooperating with a region on the rock
drilling
machine for preventing separation of the coupling sleeve and the rock drilling
machine, wherein percussion energy is transmitted from the rock drilling
machine to
the rock bolt during a percussion operation when the locking device is
unloaded, and
said locking device is loaded to retain the rock drilling machine connected to
the
coupling sleeve only when said rock bolt is disconnected from said coupling
sleeve
by rotation of said rock drilling machine in a direction for disconnecting
said first part
of said coupling sleeve from said rock bolt for reinforcing a rock with said
rock bolt.
2. The coupling sleeve as claimed in claim 1, wherein said locking device
comprises at least one locking pin for engaging said drilling machine through
at least
one opening in said coupling sleeve.
4

Description

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Coupling sleeve for connection of a threaded rock bolt to an impact rock
drilling
machine
The present invention relates to a coupling sleeve for connection of a
threaded rock bolt to an impact rock drilling machine more specifically the
invention is
about a specific design of the coupling sleeve which secures that a certain of
the two
threaded connections of the coupling sleeve is loosened first when the rock
drilling
machine is disconnected from the rock bolt.
In a previously known solution for securing that a certain thread
connection is loosened first, see SE 433 097, one uses threads with different
pitches,
different threads or cones in order to achieve a thread connection which is
substantially more difficult to loosen than the other. These solutions have
the
drawback that one must use nonstandard parts. All the time one also must check
which end is which in order to achieve correct connection.
In an attempt to solve the above mentioned problem, see
WO 02/057591, a sleeve is clamped on the thread which is to be difficult to
loosen. It
has turned out that this solution has the drawback that it cannot take the
shock wave
loads to which the thread connection is exerted during drilling.
Some embodiments of the present invention aim at doing away with the
above mentioned drawbacks by providing the coupling sleeve with a locking
device
which cooperates with a region in the shank adapter of the rock drilling
machine in
order to prevent that the coupling sleeve and the rock drilling machine are
separated
when the rock drilling machine and the rock bolt are separated.
According to one aspect of the present invention, there is provided a
coupling sleeve for connecting a threaded rock bolt to an impact rock drilling
machine, said coupling sleeve comprising a first part provided with an
internal thread
for connection of the rock bolt, and a second part provided with an internal
thread for
connection of the rock drilling machine, wherein the second part comprises a
locking
device arranged substantially transversely to a longitudinal axis of the
coupling
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sleeve, said locking device cooperating with a region on the rock drilling
machine for
preventing separation of the coupling sleeve and the rock drilling machine,
wherein
percussion energy is transmitted from the rock drilling machine to the rock
bolt during
a percussion operation when the locking device is unloaded, and said locking
device
is loaded to retain the rock drilling machine connected to the coupling sleeve
only
when said rock bolt is disconnected from said coupling sleeve by rotation of
said rock
drilling machine in a direction for disconnecting said first part of said
coupling sleeve
from said rock bolt for reinforcing a rock with said rock bolt.
An embodiment of the invention is described below with reference to
the accompanying drawing in which fig 1 shows a perspective view of a coupling
sleeve according to the invention and a shank adapter and a rock bolt for
cooperation
with the coupling sleeve. Fig 2 shows a section through the device according
to fig 1
with rock bolt and rock drilling machine connected to the coupling sleeve.
Fig. 3
shows the coupling sleeve with the locking device loaded and the rock bolt
separated
from the coupling sleeve.
The coupling sleeve shown in the drawing comprises a first part 3
provided with an internal thread 4 to which a threaded rock bolt 1 is
connectable.
The threaded rock bolt is provided with a not shown drill bit for drilling of
the hole in
which the rock bolt is to be anchored. The coupling sleeve comprises also a
second
part 5 provided with an internal thread 6 to which a rock drilling machine 2
is
connectable. In the drawing the shank adapter belonging to the rock drilling
machine
is shown. The coupling sleeve has a longitudinal axis 9. The coupling sleeve
is in its
second part 5 provided with two transversely to axis 9 arranged borings 10 in
which a
locking device 7 in form of two spring pins is arranged. The locking device 7
cooperates with a region 8 in order to prevent that the coupling sleeve and
the rock
drilling machine 2 are separated.
When setting a rock bolt 1 the shank adapter belonging to the rock
drilling machine 2 is rotated at the same time as it is exerted to impacts.
Through this
a hole is drilled with rock bolt 1 in which hole the rock bolt is to be
anchored. During
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drilling the locking device 7 is unloaded, as illustrated in Fig. 2. After
drilling the rock
bolt 1 is to be separated from the coupling sleeve and left in the rock.
Hereby the
rock drilling machine is rotated for loosening of the thread connection.
Through
cooperation between the locking device 7 and region 8 which has a smaller
diameter
than the thread of the shank adapter it is prevented that the rock drilling
machine 2
and the coupling sleeve are separated, as illustrated in Fig. 3. After that
the drillhole
is filled around the rock bolt with cement or resin for anchoring of the rock
bolt in the
borehole.
3

Dessin représentatif