ATTACHMENT MEANS FOR SECURING A ROCK BOLT DOLLY TO DRILL STEEL

DISPOSITIF DE FIXATION D'UNE TIGE DE BOCARDAGE A UN FLEURET DE FORATION

English Abstract

ABSTRACT
The invention relates to a novel attachment means
useful in fixedly interconnecting polygonal drill steel to
a rock bolt dolly when the drill steel is inserted into
complementary socket means provided at one end of the dolly.
Heretofore, accidental disengagement of the drill steel from
the dolly was relatively common often resulting in injury
to workers and lost operating time. When in their socketed
mode, a length of mild steel rod is welded along one of its
end portions to the rock bolt dolly and the other end portion
is tightly wound about the drill steel so that this winding
abuts a collar on the drill steel intermediate the rock
bolt dolly and the winding when the drill steel is socketed
to the dolly.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Attachment means for fixedly interconnecting
polygonal drill steel which is coupled to the complementary
socket end of a rock bolt dolly and wherein said drill steel
includes a collar adjacent the dolly when two are coupled
together, said attachment means comprising a length of mild
steel rod one end portion of which is welded to the side of
the dolly and the other end portion is at least once tightly
wound about and in at least partial abutting engagement with
the side of the collar of the drill steel remote from said
dolly.
2. The attachment means as claimed in claim 1 wherein
said one end portion which is welded to the side wall of
said dolly is in substantial axial alignment with the dolly and
the drill steel.
3. The attachment means as claimed in claim 2, wherein
said other end portion of said mild steel rod is wrapped about
said drill steel in a pig-tail.
4. A process for fixedly interconnecting a socketed
polygonal drill steel section to a rock bolt dolly where said
section includes a collar disposed adjacent to said dolly by
welding one end portion of a length of mild steel rod to said
dolly and snugly winding a portion of the remainder of said
rod about said section and in at least partial abutting
relationship with that side of the collar remote from the dolly.

Description

9~5~
This invention relates to a novel attachment means
used in fixably interconnecting polygonal drill steel to rock
bolt dollys which are used in mining to secure rock bolts in
place.
Rock bolts are commonly employed in the mining
industry and are commonly used as a means to structurally
enhance or support the surrounding walls of undergound exca-
vations. These bolts, using conventional drills or jack legs
as a power source can be tightened in situ employing different
lengths of polygonal drill steel which have been attached to the
free end thereof, a rock bolt dolly. One end of the dolly is
provided with a polygonal socket receptacle which is adapted
to slidingly engage the complementary free end of the drill
steel. The other, generally enlarged end of the dolly also
includes a socket receptacle so dimensioned as to graspingly
engage for tightening the nut portion of a rock bolt. Typical
rock bolt dollys to which this invention has application are
those currently in use by International Nickel Company of
Canada Limited in Sudbury and which are manufactured by
Fah Ralloy Canada Ltd. of Orillia, Ontario.
Heretofore, no satisfactory coupling arrangement
between the inter-engaging ends of the drill steel and rock
bolt dolly has been devised. By its very nature, polygonal
drill steel is not susceptible to welding so that it and the
dolly can be joined together. Further, due to the hardness of
the drill steel, attempts to drill through the common inter-
engaging ends of the drill steel and dolly for the purpose of
pinning the two together has not proved successful.
Because the socket interconnection between the drill

i~
steel and dolly is prone to disengage and the dolly itself is
relatively heavy, serious accidents have been occasioned. This
may result when the dolly separates from the drill steel
during the tightening operation and then hits a nearby operator
or miner. The dolly has also been known to separate from the
drill steel after bolt tightening and remain stuck to or other-
wise jammed on the nut end of a rock bolt. Where located
overhead, these separated dollys, can over time, dislodge
themselves and cause serious injury to a person underneath.
In addition to the hazard problem inherent in the use of rock
bolt dollys as described above, a supply of dollys must always
be on hand in situations where they become fastened to and
left attached on rock bolts. Indeed, the dolly and drill steel
mating components can become separated during stacking or rough
handling causing needless annoyance and wasted time.
In accordance with my invention, I have developed a
novel way in which to fixably interconnect socketed drill steel
or drill steel sections to rock bolt dollys which overcomes the
serious and significant disadvantages set out above. The end
of the polygonal drill steel which sockets into complementary
means in one end of the dolly is provided with or so worked as
to include a collar which is adjacent the dolly when the two are
coupled together. The attachement means is made up of a length
of mild steel rod due to its welding ability. As the dolly
itself is also capable of being welded, I then weld one end
portion of the rod securely to the side of the dolly and cause
the remaining unwelded portion to be at least once tightly
wrapped or wound about the drill steel on the side of the collar
of the drill steel remote from the dolly so that the wound
portion of the rod is in at least partial abutting engagement
with the collar. This results in a secure and firm connection
--2--

between the dolly and drill~teel and one which will not separate
during use or through rough handling.
In accordance with a preferred embodiment of my
invention, the one end portion of the mild steel rod is welded
to the side wall of the dolly so that it is in substantial
axial alignment with the dolly and drill steel. This affords
a adequate surface area exposure of the rod on the dolly for a
secure weld yet minimizes the amount of rod required. The
remaining portion of the rod not welded to the dolly is then
worked by known means so that it becomes wrapped about the
drill steel in a curl or pig-tail. It will also be evident
without departing from the scope of my invention that the
curled portion of the rod may first be wrapped about the drill
steel and the other end then welded to the dolly when the
complementary ends of the drill steel and dolly are inter-
connected. It will also be apparent that even if there is some
axial displacement in the socket coupling, the attachment means
engaging the collar component of the drill steel constrains
the latter from withdrawal of the dolly socket.
In the accompanying drawing, a working embodiment
of my attachment means used in fixedly securing a typical rock
bolt dolly to a polygonal section of drill steel is shown.
Rock bolt dolly 1 is in the form of an elongate
truncated cone and at its enlarged end is provided with socket
2 which itself is normally dimensioned so as to receive and
grasp the complementary or nut end of a rock bolt (not shown).
The other end of dolly 1 similarly includes a socket 3 outlined
in chain-line and is adapted to engage, in complementary
fashion, the polygonal outer walls 4 of drill steel 5. Drill
steel 5 can of course be of any desired length to meet the
job requirements. End 6 is intended to be engaged by and

~3SC ~6
driven by a drill or jack leg (not shown). Collar or abuttment
7 is a common characteristic of drill steel but this is not
the case with collar 8 adjacent the dolly which is made using
well-known techniques.
Without the benefit of attachment means 9 discussed
in greater detail below, it is apparent that drill steel 5
can be withdrawn from socket 3 of dolly l. By welding end 10
of attachment means 9 which is made up of mild steel rod at
weldment ll and curling or winding the other end of the rod 12
about drill steel 5 so that at least a portion of this winding
or pig-tail abuts collar 8 on its side remote from dolly l, it
will be evident that withdrawal of the drill steel 5 from dolly
l is inhibited and the two can only be separated by the active
removal of the attachment means.