Note: Descriptions are shown in the official language in which they were submitted.
PUS~ING TOOL
TEC~NICAL FI~LD
The instant invention relates to mining equipment in general
and, more particularly, ~o ~ tool for loading cable, e~plosives and
other objects into apertures formed in excavations.
BAC~GRO~D A~T
Rock (or roof) boltR bave been a traditionsl mainstay of
underground mining. The bolts are inserted into the roof of an
excavation to tie the ground together and enhance the strength of the
overhead arch.
Rock bolt~, ~hich ~ay be 4 feet (1.2 ~) or more in length
are inserted into hole~ drilled into the roof. They sre generally
fitted with an anchoring arrange~ent at the upper end and a heavy
plate wa~her at the lower end. Turning the head of the bolt at the
lower end actuates the anchorsge and stresses the bolt and the roof
in compre 8 ~ ion.
Recently however~ mining eDgineers have sought to reduce the
reliance on rock bolting in an attempt to lower mining costs and to
improve efficiency. Rock bolting i6 labor intensive and requires a
large inventory of costly rock bolts. Accordingly, in some iDstance6,
cable bolting has replaced, or at least supplemented, rock bolting.
~z~
In order to secure the ground, spaced holes on th2 order of
about 40~50 feet (12.2 ~ 15.3 m) deep are drilled into the roof. A
heavy 1~2 inch (1.27 cm) diameter steel cable is forced up into the
hole. A small holding tube is inserted into the hole and adjacent to
the cable. Shotcrete is then extruded into the hole. By allo~ing
the shotcrete to harden, a reinforced beam is formed within the hole
to stabilize and secure the ground from collapse.
A difficulty posed by the cable bolting technique i~ the need
for three men to manually force the heavy cable into the roof hole6.
The physical labor needed to accomplish this ta~k is difficult, time
consuming, inefficient and, as a consequence, unacceptable.
SUMMARY OF T~E I~VENrI~
Accordingly, there i6 provided a power-driven pushing tool
that forces cables and other ma~erials (such a~ explosives) into a
hole. The pu~hing tool efficiently decreases the time necessary to
force a long, heavy cable into the hole and frees up manpower for
other more productive pur~ui~.
The tool includes a power driven, reciprocating telescopic
drive, a suppor~ therefor, and a dogging mechanism for alternately
gripping and feeding the cable (or object) into the hole and
relea~ing the cable to begin the feeding process anew.
BRI~F DESCRIPTION OF ~ D~AWI~G
Figure 1 is an elevation of an embodiment of the invention.
Figure 2 is an elevstion of an embodiment of the invention.
Figure 3 is 8 view taken along line 3-3 in Figure 1.
Figure 4 is a view taken aloDg line 4-4 in Figure 19
~ igure 5 i~ a detailed view of a feature of the invention.
~22~
PREF~RRED MOD~ FOR GARRYING OV~ TH~ [NVENTIO~
Referring to Figures 1 and 2, ~here il5 shown a pushing tool
10. The tool 10 includes a po~er driven tele6copic leg 12. The leg
12 may be powered by pneumatic, hydraulic or electrical energy. In the
embodiment shown9 a JMG Air-Leg* (a pneumatic atoper leg) i~
utilized. The leg 12, which in this instance i6 a cylinder, includes
a telescopic piston 56 which may be extended and retracted at will.
The stroke of the piston 56 1~ controlled by valve 26. In this
embodiment, pneumatic lines 28 and 30 supply power to the leg 12. The
valve 26 also exhausta air to the environment during the retraction
of the piston 56. The valve 26 may be manual or automated.
The leg 12 is provided with a spider support 14 at its base.
A slidable stabilizer rod 16 is dispo~ed adjacent to the leg 12. The
rod 16, when lowered, may be parked in cup 50. The rod 16 vertically
alide6 within, and is supported, by rod guide 18 and rod clamp 20.
The clamp 20 includes bolt and wing nut 22 which serve to iock the
rod 16 in any position.
Frame 24 i~ affixed to the end of the piston 56. The fr~me
24 includes cable guide 32 and dogging mechanism 34. CAble 36 pasæes
through the guide 32 and the dog 34.
Figure l deno~es the tool 10 in the retracted po~ition,
whereas Figure 2 depicts the tool lO in the extended position.
Referring to Figure 3, it may be observed that the J-shaped
guide 32 is affixed to the frame 24. It has been determined that the
inner dimension 38 should ~e about 1/8 of an inch (3.2 mm) larger
than the thickness of the cable 36. The cable 36 slidingly fit~ into
the crook of tbe guide 32.
Referring now to Figures 4 and 5, the dog 34 includes cla~p
40, eccentric 42 and mount 44. These components, comprising the dog
34, are pivotally mounted together Vi8 fasteners 46. Inner dimension
48 i~ preferably about l/16 of an inch (1.6 mm) larger than the
thickness of the cable 36. The high and low points on the eccentric
42 are represented by numeralR 52 and 54 respectively. The mount 44
is affixed to the frame 24.
*Trademark
~22~63~
The invention and the manner of applying it may, perhaps, be
better understood by a brief discussion of the principles underlying
the invention.
After 8 hole i8 drilled into the roof of an ex~avation, the
tool 10 is vertically oriented under the hole and ~upported by the
spider i4. The appropriate power lines are hooked up by means Xnown
to tho~e skilled in the art. The stabilizer rod 16 is extended
upwardly against the roof for sdditional support. The nut 22 is
tightened against the rod 16 to secure the rod 16 and, as a
consequence, the tool 10 in the proper position. The cable 36 i8
threaded through the guide 32 and the clasp 40 and finally into the
hole in the roof. The tool 10 is energized by throwing the valve 26.
As the pistcn 56 commenceR its upstroke, the eccentric 42 is forced
by inertia to rotate downwardly thereby forcing the high poin~ 52 to
bite into the cable 36. See Figure 2. This biting action causes the
cable 36 to be drawn up into the hole as the piston 56 con~inues in
the up direction.
After the piston 56 has reached the desired height, the valve
26 is reversed, causiag the piston 56 to retract. Initially, as the ~~~
piston 56 retract~, the eccentric 42, again due to(i~ertia),-~wlrr
rotate upwardly breaking the contact between the hi~h point 52 and
the cable 36. See FigurPs 1, 4 and 5. This ratchet-like releasing
action allow~ the piston 24 to react ~ithout simultaneou~ly drawing
down the cable 36. The low point 54 clears the cable 36 during the
downward stroke.
Upon reenergization, the doggi~g mechanism 34 will again
grip the cable 36 a~d force it further in the hole. This
reciprocating ratchet-like action i8 repeated until the cable 36 is
positioned within the hole to the predeter~ined depth.
In order to improve the gripping and wearability character-
istics of the clasp/ eccentric combination 40/42, it i~ helpful to
weld ~ few bead~ of metal onto the ecce~tric 42.
The tool 10 may be utilized for forcing explosives and other
objects into the hole. Moreover, it should be appreciated that the
tool 10 may be placed in orientations other than the vertical.
While in accordance with the provisions of the statute,
there is illustrated and described herein specific embodi~ents of the
invention, those skilled in the art will understand that changes may
be made in the form of the invention covered by the claims and that
certain features of the invention may sometime6 be used to advantage
without a corresponding use of the other features.
