CA1043767A - Drilling boom - Google Patents
Drilling boomInfo
- Publication number
- CA1043767A CA1043767A CA234,452A CA234452A CA1043767A CA 1043767 A CA1043767 A CA 1043767A CA 234452 A CA234452 A CA 234452A CA 1043767 A CA1043767 A CA 1043767A
- Authority
- CA
- Canada
- Prior art keywords
- hydraulic cylinder
- boom
- cylinder assembly
- assembly
- feed bar
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- Earth Drilling (AREA)
Abstract
ABSTRACT OF THE INVENTION
The present invention provides a drilling boom assembly comprising: a telescopic boom, the boom being expandable and contractable in length and having a first end and a second end, the first end being hinged to a pivot mounted on a bearing plate, the pivot and the boom being pivotal relative to the bearing plate about a vertical axis; a first hydraulic cylinder assembly for controlling the length of the boom, the first hydraulic cylinder assembly being carried by the boom;
a feed bar hinged to the second end of the boom, the feed bar being provided with a drifter and having a working end, the feed bar being axially movable forwards and backwards relative to the second end of the boom by means of a second hydraulic cylinder assembly, the second hydraulic cylinder assembly being mounted on the boom; a third hydraulic cylinder assembly for tilting the feed bar in a vertical plane, the third hydraulic cylinder assembly being connected to the boom; a fourth hydraulic cylinder assembly for turning the feed bar in a horizontal plane, the fourth hydraulic cylinder assembly being connected to the boom; a mechanism for rotating the feed bar about an axis parallel to the axis of the feed bar; a fifth hydraulic cylinder assembly for lifting the boom, one end of the fifth hydraulic cylinder assembly being hinged to the boom, the other end of the fifth hydraulic cylinder assembly being hinged to the pivot; a sixth hydraulic cylinder assembly for turning the telescopic boom in a horizontal plane, one end of the sixth hydraulic cylinder assembly being hinged to the bearing plate; a servomechanism for controlling operation of either the first or alternatively the second hydraulic cylinder assembly (hereinafter referred to as the controlled cylinder assembly), the servomechanism comprising a support rod, a seventh hydraulic cylinder assembly mounted on the rod and a servovalve, each of the aforementioned hydraulic cylinder assemblies comprising a respective cylinder accommodating a piston defining a first variable volume space and a second variable volume space in the cylinder, the first variable volume space of the seventh hydraulic cylinder being in communication with the first variable volume space of the controlled cylinder, said communicating spaces being equal in volume at any one time, the servovalve comprising a body and a plunger accommo-dated in the body and attached to the rod, the body having a first duct for supply of working fluid in to the servovalve, a second duct communicating with the second variable volume space of the controlled cylinder for supplying working fluid to that space and a third duct communicating with the second variable volume space of the seventh hydraulic cylinder for return of working fluid from that space, the plunger controlling communication between the ducts; and A connecting means coupling the rod with the boom which causes the seventh hydra-ulic cylinder assembly and the body of the servovalve to dis-place with respect to the plunger, thus bringing the first duet into communication via the second duct with the second variable volume space of the controlled hydraulic cylinder assembly, thus either extending or retracting the controlled hydraulic cylinder assembly and compensating to maintain the working end of the feed bar in a desired vertical plane, when either (1) the controlled cylinder assembly is the first hydraulic cylinder assembly and the boom turns in a vertical plane or (ii) the controlled cylinder assembly is the second hydraulic cylinder assembly and the boom turns in a horizontal plane
The present invention provides a drilling boom assembly comprising: a telescopic boom, the boom being expandable and contractable in length and having a first end and a second end, the first end being hinged to a pivot mounted on a bearing plate, the pivot and the boom being pivotal relative to the bearing plate about a vertical axis; a first hydraulic cylinder assembly for controlling the length of the boom, the first hydraulic cylinder assembly being carried by the boom;
a feed bar hinged to the second end of the boom, the feed bar being provided with a drifter and having a working end, the feed bar being axially movable forwards and backwards relative to the second end of the boom by means of a second hydraulic cylinder assembly, the second hydraulic cylinder assembly being mounted on the boom; a third hydraulic cylinder assembly for tilting the feed bar in a vertical plane, the third hydraulic cylinder assembly being connected to the boom; a fourth hydraulic cylinder assembly for turning the feed bar in a horizontal plane, the fourth hydraulic cylinder assembly being connected to the boom; a mechanism for rotating the feed bar about an axis parallel to the axis of the feed bar; a fifth hydraulic cylinder assembly for lifting the boom, one end of the fifth hydraulic cylinder assembly being hinged to the boom, the other end of the fifth hydraulic cylinder assembly being hinged to the pivot; a sixth hydraulic cylinder assembly for turning the telescopic boom in a horizontal plane, one end of the sixth hydraulic cylinder assembly being hinged to the bearing plate; a servomechanism for controlling operation of either the first or alternatively the second hydraulic cylinder assembly (hereinafter referred to as the controlled cylinder assembly), the servomechanism comprising a support rod, a seventh hydraulic cylinder assembly mounted on the rod and a servovalve, each of the aforementioned hydraulic cylinder assemblies comprising a respective cylinder accommodating a piston defining a first variable volume space and a second variable volume space in the cylinder, the first variable volume space of the seventh hydraulic cylinder being in communication with the first variable volume space of the controlled cylinder, said communicating spaces being equal in volume at any one time, the servovalve comprising a body and a plunger accommo-dated in the body and attached to the rod, the body having a first duct for supply of working fluid in to the servovalve, a second duct communicating with the second variable volume space of the controlled cylinder for supplying working fluid to that space and a third duct communicating with the second variable volume space of the seventh hydraulic cylinder for return of working fluid from that space, the plunger controlling communication between the ducts; and A connecting means coupling the rod with the boom which causes the seventh hydra-ulic cylinder assembly and the body of the servovalve to dis-place with respect to the plunger, thus bringing the first duet into communication via the second duct with the second variable volume space of the controlled hydraulic cylinder assembly, thus either extending or retracting the controlled hydraulic cylinder assembly and compensating to maintain the working end of the feed bar in a desired vertical plane, when either (1) the controlled cylinder assembly is the first hydraulic cylinder assembly and the boom turns in a vertical plane or (ii) the controlled cylinder assembly is the second hydraulic cylinder assembly and the boom turns in a horizontal plane
Description
~37~7 The present inv~ntion re~-ltes to a drilling boom assembly secured on a drilliny carriage or on a drilling riy and use-l in driving mine openings and in stoping.
A known drilling boom assembly comprises a telescopic boom with an ac~uating hydraulic cylinder, said boom being hinged with its one end to a pivot mounted on a bearlng plate.
The boom can turn round its own axis. Hinged to a free end of the telescopic boom is-a feed bar with a drifter, said feed bar being provided with a hydraulic cylinder. Rigidly fixed to this free end of the telescopic boom is a head carrying hydraulic cylinders for til-ting and swivelling the feed bar in a horizontal plane as well as a rotational mechanism to turn the feed bar round the axis of -the rotational mechanism ' which axis is parallel to that of the feed bar.
Change of the angle of inclination of the telescopic boom in a vertical plane is accomplished by means of a hydraulic cylinder whose rod free end is hinged to the boom, while its body is articulated to the pivot.
Turning the telescopic boom in a horizon-tal plane is accomplished by means of a hydraulic cylinder whose rod free ; end is articulated to the bearing plate.
A disadvantage of the known drilling boom is that lifting or turning of the boom causes the distance between the feed ~ar and a rock face to vary. Also, the horizontal angle and .
the vertiGal angle of the feed bar with respect to the rock face become altered.
This occurs when lifting the telescopic boom in a vertical plane and turning the boom in a horizontal plane.
Alignment of the working end of the feed bar with the hole is a rather laborious and time-consuming operation.
It is an object of the present invention to provlde a drilling boom assembly that automatically compensates for '~
~37~
cleviation o~ the end of ~he manipu].ator fron~ the face, ~hile ~- swinginy the telescopic manipulator.
According to the present invention, there is provided ~: a drilling boom assembly comprising, a telescopic boom, the boom being expandable and contractable in lenyth and having a first end and a second end, the first end being hinged to a pivot mounted on a bearing plate, the pivot and the boom being pivotal relative to the bearing plate about a vertical axis, a first :
hydraulic cylinder assembly forming part of the boom for control- -~j 10 ling the length thereof, a feed bar hinged to the second end of ~ . :
``¦ the boom, the feed bar being provided with a drifter and having :
' a working end, the feed bar being axially movable forwards and ~' backwards relative to the second end of the boom by means of a second hydraulic cylinder assembly, the second hydraulic cylinder q ~ assembly being mounted on the second end of the boom, a third :, hydraulic cylinder assembly for tilting the feed bar in a vertical j plane, the third hydraulic cylinder assembly also being mounted on the second end of the boom, a fourth hydraulic cylinder assembly for turning the feed bar in a horizontal plane, the fourth hydraulic cylinder assembly also being mounted on the second . end of the boom, a mechanism for rotating the feed bar about an ~ axis parallel to the axis of the feed bar, a fifth hydraulic cylinder assembly for lifting the boom, one end of the fifth . hydraulic cylinder assembly being hinged to the boom, the other end of the fifth hydraulic cylinder assembly being hinged to the pivot, a sixth hydraulic cylinder assembly for turning the tele-~ ~:
: scopic boom in a horizontal plane, one end of the sixth hydraulic cylinder assembly being hinged to the bearing plate, the other end ` of the sixth hydraulic cylinder assembly bein~ hinged to the boom, - 30 a servomechanism for controlling operation of either the first or ~ alternatively the second hydraulic cylinder assembly, the cylinder assembly controlled by the servomechanism hereinafter being ,. .
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referred to as the controlled cylinder assembly, the servo-mechanism comprising a support rod, a seventh hydraulic cylinder assembly and a servovalve, one end of the seventh hydraulic cylinder assembly being connected to the pivot and the other end thereof being connected to the support rod each of the afore-mentioned hydraulic cylinder assemblies comprising a respective cylinder accommodating a piston defining a first variable volume space and a second variable volume space in the cylinder, the first variable volume space of the seventh hydraulic cylinder being in communication with the first variable volume space of . .
the cylinder of the controlled cylinder assembly, said communic-ating spaces being equal in volume at any one time, the servovalve comprising a body and a plunger accommodated in the body and attached to the rod, the body having a first duct for supply of working fluid to the servovalve, a second duct communicating with the second variable volume space of the controlled cylinder for supplying working fluid to that space and a third duct communic-ating with the second variable volume space of the seventh hydra-ulic cylinder for return of working fluid from that space, the plunger controlling communication ~etween the ducts, and a connec-ting means coupling the rod with the boom which causes the seventh hydraulic cylinder assembly and the body of the servovalve to displace with respect to the plunger, thus bringing the first duct into communication via the second duct with the second variable volume space of the controlled hydraulic cylinder assembly, thus `
either extending or retracting the controlled hydraulic cylinder assembly and compensating to maintain the working end of the feed bar in a desired vertical plane, when either (i) the controlled cylinder assembly is the first hydraulic cylinder assembly and the boom turns in a vertical plane or (ii) the controlled cylinder assembly is the second hydraulic cylinder assembly and the boom turns in a horizontal plane.
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371~7 It is expedient that the servomechanism drive be secured on the boom, with the piston-end space or rod-end space of the boom actuating hydraulic cylinder communicating ,1 ' .
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~3~ ;7 with the respect:ive rod-end s~!~ce or piston-end space of the servomechanism clrive hydraulic cylinder, and that thc connecting means include a slide block. tn this case vertical lifting of the boom will cause the slide block to move along the guideways to displace -the body of the servomechanism drive hydraullc cylinder.
It is also preferable that the servomechanism drive be secured on the bearin~ plate, with the piston-end space or rod-end space of the feed hydraulic cylinder communicating with the respective space of the servomechanism drive hydraulic cylinder. Preferably, the connecting means is provided with -; a tie rod hinged to the servomechanism drive hydraulic cylinder body, said connecting means being secured on a pivot by means .~ - .
of an arm. In this case horizontal turning of the boom causes the tie rod to move with respec-t to the axis of the pivot to displace the body of the servomechanism drive hydraulic cylinder.
drilling boom assembly embodying the invention is described below with reference to the accompanying drawings, wherein:
~ Figure 1 is a general schematic side view of the ,! drilling boom assembly, in a horizontal position (I)l in a lifted position (II) and in a lowered position (III).
I Figure 2 is a plan view of the drilling boom assembly of Figure 1, Figure 3 is a vertical elevation of a bearing plate carrying a pivot, a boom actuating hydraulic cylinder and a servomechanism drive;
Figure 4 is a longitudinaI, partly sectional, view 3Q of a boom of the drilling boom assembly of Figures 1 and 2;
Figure 5 is a cross-section taken along line V-V
in Figure 4;
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7~7 Figur~ 6 is a lonc~itllclinal sec-tional view of a hydraulic cylinder ~or controll:ing the lenc3th of ~he boom shown in Figure 4;
Figur~ 7 is a longitudinal sectional view of a hydraulic cylinder for lifting the boom through a vertical plane Figure 8 is a longitudinal sectional view of a drive of a servomechanism;
Figure 9 is a longitudinal sectional view of a valve of the servomechanism drive; and Figure 10 is a schematic representation of the drill-ing boom assembly of Figure 1.
The drilling boom assembly shown in the drawings icomprises a telescopic boom 1 (Figure 1). One end of the boom ~ -is secured on a pivot 2 which is mounted on a bearing plate 3 so that the pivo-t 2 together with the boom 1 may turn about a ver-tical axis l. A feed bar 4 is hinged to the end of the boom remote from the pivot 2, i.e. the free end of the boom.
The feed bar 4 is provided with a dr:ifter 5. The feed bar 4 - comprises a hydraulic cylinder 6 and i5 connected to a head 7 which is rigidly fixed to the free end of the boom. The boom 1 accommodates an actuating hydraulic cylinder 8. The head 7 is provided with a hydraulic cylinder 9 for tilting the feed bar 4 through a vertical plane and a hydraulic cylinder 10 ~Figure .~ 2) for turning the feed bar 4 through a horizontal plane. The ;~
head also carries a rotational mechanism 11 ~Figure 1) for rotating the feed bar 4 through an angle of up to 180 about an axis 23 parallel to the axis of the feed bar. Provision -~
of the rotational mechanism 11 makes it possible to carry out drilling operations to produce parallel holes in a rock face at a small distance from the rock walls and roof of a mine opening and, moreover, almost fully excludes a 'dead zone' on ~-. ~ .
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thc ~ace whe~ein drillillg is iml~ossible. ~ hydraulic cylinder 1.2 ~or :liEting !:he tc:l.escoE~ic boom through a vertical r~Lane is hinyed at one end to said boom. The other end of the hydraulic ; cylinder 12 is secured on the pivot 2 by means of a joint 13.
The drilling boom assembly also comprises a hydraulic cylinder 14 (Figure 2) for turning the telescopic boom in a horizontal plane.
The drilling boom assembly is provided with a servomechanism 15 for controlling operation of the hydraulic actuating cylinder 8 of -the boom. The servomechanism 15 comprises a drive 15a secured on the telescopic boom 1 and a - connecting means 16.
.:: The drilling boom assembly also carries a servo- .
mechanism 17 (Figure 3) which is similar.in design to the servomechanism 15 and is for controlling operation of the hydraulic cylinder 6 of the feed bar 4. The servomechanism 17 comprises a drive 17a secured on the bearing plate 3 and a connecting means 18 for connecting servomechanism 17 to pivot 2.
The telescopic boom 1 (Figure 4) is provided with an ~l 20 eye 19 and a groove "a" (Figure 1). The guideway 20 is rigidly .~ fixed to the pivot 2 and.forms part of the connecting means 16 l of the servomechanism 15. The guideway 20 slidingly supports :' ! a slide block 21 which is rigidly fixed to the hydraulic cylinder of the servomechanism and forms part of the connecting means 16. The telescopic boom comprises a body 22 (Figure 4).
The actuating hydraulic cylinder 8 incorporates bronze bushes .-' 23 and bronze liners 24 (Figures 4 and-5). A rod 25 of the -actuating hydraulic cylinder 8 is connected with the body 22 of the telescopic boom 1. The body 22 of the telescopic boom is coupled with a rod 26. The rod 25 is held against rotation about its own axi.s by means of keys 27 and 28 housed in grooves "b" and "c" of the body 22. The body 22 is provided with ~: - 6 -,, ~ ' . .
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as~embly ports "cl" (Figure 4) -lncl "e" tFigure 5) normally closed with cov~rs 29 (I~'icJure 4) and 30 (Figure 5).
The actuating hydraulic cylinder 8 comprises a body 8a. The body 8a (Fiyure 6) accommodates the rod 26. ~ piston 31 is fixed to the rod 26. A support 32 provided with an eye ; 32a is welded to the rod 26. A support 33 provided with an eye 33a is welded to the body 8a. Working fluid is fed to a piston-end space "f" of the cylinder and to a rod-end space "g"
-through respective inlets 34 and 35 provided in the support 32.
The working fluid is oil. Sealing of working spaces "f" and "g" is effected by means of collars 36, 37 and 38. The piston 31 on the rod 26 is sealed by means of rubber rings 39 and 40.
i From the inlet 34-the working fluid flows to the space "f" via -, a pipe 41 sealed with rubber rings 42 and 43. A bush 44 is held in the body 8a with the help of a rubber ring 46. Mud removers 47 and 48 are secured by means of a cover 49 and cotter pins 50 and 51.
The servomechanism 15 and 17 can be used in drilling boom assemblies of any type and, particularly, on drilling boom assemblies adap-ted to maintain paral:Lelism of the feed motion , and operating on the principle of hydraulic parallelogram.
As shown in Figure 7, the hydraulic cylinder 12 :1 !
comprises a pilot cylinder 52 employed in a hydraulic parallel-ogram circuit and a hydraulic cylinder 53 for lifting the telescopic boom-in a vertical plane. Rods 54 and 55 of hydraulic cylindars 52 and 53 are interconnected by means of nut 56 fixed on the rod 55 with a cotter pin 57 retaining said nut against spontaneous unscrewing. Pistons 58 and 59 are secured on the rods 54 and 55. Sealing of the spaces of the hydraulic cylinder 52 is effected by means of collars 60 to 66 and rubber rings 67 -to 73. A bush 74 is held in a body 75 by means ; of a snap ring 76. Mud removers 77 and 78 are retained with a ~'`
, 3~ 7 cove~r 79 and cotter pins 80 an~l 81. A bush 82 is secured between thc body 75 and a body 83 which are interconnecte~ h bolts ~4 and ~5. Rod-end and piston-end spaces of the pilot cylinder 52 are hydraulically intercommunicated through connections 86 and 87 with the respective spaces of the hydra-ulic cylinder 9 (Figure 1) for tilting through a vertical plane the feed bar 4 and are equal in volume with the spaces of the hydraulic cylinder 9.
The hydraulic cy]inder 12 for lifting the telescopic boom 1 and the hydraulic cylinder 9 for tilting the feed bar 4 thus operate in unison. Thus, the inclination of the feed bar 4 always remains the same, irrespective of the inclination of the boom 1 to the vertical, i.e. said cylinders ensure operation of a "hydraulic parallelogram."
The drive 15a of the servomechanism 15 is secured on the body 22 of the telescopic boom 1 by means of brackets 88 ~' .
and 89 (Figure 8). The drive 15a comprises a hydraulic cylinder 90 having a body 91 connected with tlle slide block 21 (Figure 1) through a dowel pin 92. A piston-end space "h" and a rod-end space "i" are defined within the hydraulic cylinder 90. The ~ rod end space "i"isin-ommunication with the rod-end space "g" ~ -i (Figure 6) of the actuating hydraulic cylinder 8 of the tele- ~
;, : , scopic boom 1. The rod-end space "i" of the hydraulic cylinder 90 and the rod-end space "g" of the hydraulic cylinder 8 are equal in volume at any one time. A servo-valve 95 has a body :. ~.
94 secured on the free end of a rod 93 (Figure 8) of the hydraulic cylinder 90. The body 91 of the hydraulic cylinder 90 accommodates a piston 96 provided with rings 97 and 98 and secured on the rod 93 by a nut 99. A cover 100 of the -hydraulic cylinder 90 is fixed in the body 91 by means of a snap ring 101, a washer 102, and bolts 103 and 104. Sealing of the spaces along the rod 93 is effected by means of collars A
.
376i'7 I05 to 10~ and rubber rings ll() to 112. Mud removers 113 ancl 114 are secured in the body 91 by means of a cover 115 and cotter pins 116 and 117. Mud removers 118 and 119 are secured in the body 91 hy means of the cover 100 and the washer 102.
The hydraulic cylinder 90 comprises connections 120 and 121.
cover 122 of the servo-valve 95 accommodates a collar 123 and mud removers 124 and 125 fixed by means of a cover 126 and cotter pins 127 and 128. The body 94 of the servo-valve 95 is sealed by means of rubber rings 129 and 130, said body being ~ 10 provided wi-th a connection 131 for feeding the working fluid ; into the servo-valve. The servo-valve 95 comprises a ~lunger 132 mounted on a rod 133.
`~ The body 94 (Figure 9) is provided with a duct 134 -to feed working fluid into the piston-end space "h" (Figure 8) of the hydraulic cylinder 90 of the drive 15_ of the servo-mechanism 15, a duct 135 (Figure 9) to feed the working fluid , into the rod-end space "f" (Figure 10) of the actuating hydraulic cylinder 8, ducts 136 and 137 (Figure 9) to return the working fluid Erom said spaces "h" and "f" respectively and -~
` 20 a duct 138 to feed the working fluid into the servo-valve 95.
The plunger 132 has a shoulder 139 which together with springs : .
~ 140 and 141 and washers 142 and 143 retain the plunger 132 in j ! a fixed position with respect to the rod 133. The washers 142and 143 bear against a shoulder 144 of a bush 145 coupling together two rods 146 and 147 housed-in the rod 133 (Figures 8 and 9).
The servome-chanism 17 (Figure 3) is intended to maintain constant the horizontal distance of the feed bar 4 (Figure 2) rock from the vertical rock face when turning the telescopic boom 1 and feed bar 4 in a horizontal plane. The servomechanism 17 is connected with the extending hydraulic cylinder 6. The drive 17a (Figure 3) of the servomechanism 17 ~
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~3~7i~7 is secured on the bearin~ plat~ 3 not shown, by means of brackets 148 and 149 and is provided with a rod 150, coaxially mounted on which are a servo-valve 151 and a hydraulic cylinder 152 having a body 153 connected with a tie rod 155 of the connectinc~ means 18 through a hinged joint 154. The -tie rod 155 is pivotally connected through a joint 156 with an arm 157 rigidly secured on the pivot 2. The body 153 is held against rotation around its longitudinal axis with the help of a roller 158 mounted on the bearing plate 3 and located in a groove "j"
of the body 153.
The rod-end space of the hydraulic cylinder 152 of the drive 17a communicates with the rod-end space of the ; extending hydraulic cylinder 6 (Figure 1) of the feed bar 4 and is equal in volume at any one time with the rod-end space of cylinder 6.
The drilling boom assembly is associated with a control desk (not shown) having distributors 159, 162 and 163 (Figure 10). The distributors 159, 162 and 163 are connected ; to a working fluid line (not shown).
The drilling boom assembly shown in the drawings operates as follows.
When opera-ting in a mode which allows for automatic maintainance of the distance of the feed bar 4 from a vertical rock face despite lifting of the boom, the distributor 163 is put into operation. If the duct 138 is closed by the plunger 132 and cannot communicate with ducts 134, 135 (Figure 9) working fluid cannot flow into the hydraulic cylinder 8 of the telescopic boom 1.
` To make the telescopic boom 1 move vertically, the ; 30 distributor 159 (Figure 10) is operated with the distributor 163 turned on. Working fluid from a working fluid line (not shown) is fed through the distributor 159 into the piston-,,~ ", ., :' .
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~ c "k" or in~o thc r~l-cnd sE)~ce "I" o~ Wle hy~raulic cyLinder 12.
Upon fe~in~J tlle ~rking flui.d into ~he piston-end space "k" of the hydrauli.c cylinder 12, the rod 55 is displaced and turns the telescopic boom anti-clockwise wlth resp~ct to the bearinc3 plate 3. ~s a result, the slide block 21 of the connecting means 16 of the servcmechanism 15, sliding up along the guideway 20, displaces the hydraulic cylinder 90 and, due to the fluid trapped in spaces "h" and "i", the body 94 (Figure 8) of the servo-valve 95 relative to the plunger 132 towards the bracket 89. Consequently working fluid from the working fluid line flows along the duct 138 into . 10 the duct 135 communicated with the piston-end space "f" oE the hydraulic cylinder 8, thus extending the latter and increasing the leng-th of the telescopic boom 1. Slmultaneously, -the space "h" of the hydraulic cylinder 90 comes into cGmmunication through the duct 134 with the duct 136 which i.s in communication with a return line through a pipeline 161. As the - :
hydraulic cylinder 8 extends, the working fluid expelled from the rod-end space "g" of the hydraulic cylinder 8 flows into the rod-end space "i" of the hydraulic cylinder 90 along the pipeline 160 and displaces the cylinder rod 93 (Figure 8~ which is connec-tecl to the body 34 of the servo-valve 95, relative to the plunger 132, towards the bracket 88. As a 20. result, the plunger 132 returns to the position shown in Figure 9 and the duct 138 and becornes closed once again. Thus, working fluid ceases flowing . to the duct 135 and to the piston-end space "f" of the hydraulic cylinder -;
8. Consequently, the telescopic boom is extended a length enough to co~ensate for the horizontal deviation of the end of the boom 1 away from the rock face due to the anti-clockwise moverrent of the boom; which makes it possible to drill holes whose ends are located in the s~r.e vertical plane.
. The inclination of the feed bar to the vertical is retained by rneans of the hydraulic cylinder 9 which operates together with cylinder 12 in a hydraulic parallelogram (Figure ' ~;
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10). Ul~on Eeeding the workinc~ fluid into the rod-piston space "1" of the hydraulic cylinder 12, the telescopic bcom 1 ~urns clockwise and c3ets shorter correspondingly.
When operating at a rock face, conditions may arise which require not only automatic but also independent control of the boom length and its vertical swivel. An example is found under conditions which require the change of the length of the telescopic boom without altering its angle of elevation, or vertical swivel of the drilling boom assembly with the telescopic boom length unchanged.
Provision of independent control of both the length of the telescopic boom and its vertical swivel is attained in the drilling boom assembly by virtue of servo-valves available on the con-trol desk and the springs 140 and 141 in the servo- -~ ;
valve 95, due to which the plunger displacement is relatively ~;
inconsiderable during lengthy displacement of the servopiston ~ body.
; Such independent control can occur only when the servo-valve of the servomechanism dr:ive 15a controlling the length of the boom is disconnected from -the oil line. In order to operate in an independent control mode, the distributor 163 ` (loca-ted on the control desk) for feeding the working fiuid to the servo-valve 95 of the servomechanism drive 15a is ~ ~
turned off. When the servo-valve 95 is disconnected from the ~-oil line, vertical lifting of the telescopic boom l causes -the servo-valve 95 to displace with respect to-the plunger 132, and thus the telescopic boom remains retracted. With the drilling boom assembly operating in an independent control mode, the telescopic boom may be lifted by means of the dis-tributor 159 located on the control desk.
The working rluid is fed to piston-end space "k"
of the hydraulic cylinder 12 by means of the distributor 1~9.
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~; a r~n~uLt, th~! rod 55 eY~en~s and causes the telescopic boom 1 to turn counter-clockwise with respect to the p;vot 2.
The slide block 21 moves up the guideway 20 and displaces the cylinder 90 together with the body 94 of the servor-valve 95 with respect to the plunger 132 till the butt end of the plunger 132 comes in contact with -the butt end of the rod 93 (see Figure 9). Then the body 94 of ~he servo-valve 95 con-tinues to displace towards the bracket 89 together with the plunger 132 whose collar 139 also displaces the washer 143 towards the bracket 89, thereby compressing the spring 141.
Upon feeding the working fluid into the rod-end space "1" of the hydraulic cylinder 12 (Figure 10), the tele-` scopic boom 1 turns clockwise.
~ ~ When operating in an independent control mode, the `~ telescopic boom 1 may be extended by actuating the distributor 162 (Figure 10) located on the control desk. As a result, the working fluid is fed through the distirbutor into the piston-., :
i end space "f" of the hydraulic cylinder 8 whose rod 25 ge-ts e~tended, thus increasing the length of the telescopic boom 1.
The working fluid expelled from the rod-end space "g" is fed ` through the hydraulic pipeline 160 into the rod-end space "i"
of the hydraulic cylinder 90 and urges the rod 93 together with the body 94 of the servo-valve 95 and the plunger 132 to displace towards the bracket 88, thus compressing the left-hand spring 140 (Figùre 9)-. As a result, the space "h" of the hydraulic cylinder 90 (Figure 10) of the servomechanism 15a is communicated with the return line through the distributor i62.
Upon retracting the telescopic boom the working fluid is fed through -the distributor 162 into the piston-end space "h" of the hydraulic cylinder 90. As a result, the rod 93 together with the body 94 of the servo-valve 95 and the ,.~
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37~;'7 ngcr 1.32 are displaced tow~r.cls the bracket 89, thus com-pressing the ri.cJht-hand spring 1~1 (Figure 9). The workiny ~luid e~pelled from the rod-end space "i" is fed through the hydraulic cylinder 160 into the rod-end space "g" of the hydraulic cylinder 8. As a result, the rod 25 retracts into the hydraulic cylinder 8, thus decreasing the length of the telescopic boom 1.
When changing over from an independent control of operation to an automatic one, working fluid is fed through 10 -the distributor 163, and the servo-valve 95 of the servo-mechanism drive 15a into the actuating cylinder 8. ~s a result, the springs 140 and 141 of the servo-valve 95 are set to the initial position (see Figure 9). ~:
~ The drive 15_ of the servomechanism 15 coupled w.ith the actuating hydraulic cylinder ~ o:E the telescopic bo.om 1 ; and the drive 17a of the servomechanism 17 coupled with the hydraulic cylinder 6 of the feed bar 4 are similar in design, therefore when discussing the operation of the servomechanism 17, reference is directed to the constructional units as shown in Figures ~ and 9 and to the reference numerals in the accompanying drawings.
The o~eration of the servomechanism 17 is entire ! analogous.to the mode of operation of the servomechanism 15, which has already been described. However, whilst the servomechanism I5 controls the degree of extension of tele~
scopic boom 1 in response to lifting of the boom in a vertical ~ plane, the servo-mechanism 17 controls the degree of extension of the telescopic boom 1 in response to tuning of the boom i.n a horizontal plane. Just as the servomechanism 15 could : 30 alternatively be used to control axial movement of the feed '1 bar 4 by means of the second hydraulic cylinder 6, so as to maintain the working end of the feed bar at a constant . .
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7~7 l1stance ~rom a vertical rock ~ace, so the servomechanism 17 may also alternatively control the second hydraulic cy]inder 6.
As the boom 1 attached to pivot 2 booms in a horizontal plane, the hydraulic cylinder 152 is moved by the connecting means 1~ along the rod 150. The rod 150 is rigidly fixed by means of brackets 148 and 149 to bearing plate 3.
Thus, for example, anticlockwise turning of the pivot 2 (considered from above in Figure 3) is converted by means of arm 157 on the pivot 2, tie tod 155 and hin~ed join-t 54 into axial movement of hydraulic cylinder along the rod towards the right hand side in Figure 3.
The construction of hydraulic cylinder 152 and , servovalve 151 (Figure 3) is converted by means of arm 157 on the,pivot 2, tie rod 155 and hinged joint 154 into axial !movement of hydrualic cylinder along the rod towards the right hand side in Figure 3.
The construction of hydrau:Lic cylinder 152 and servo-valve 151 (Figure 3) is substantially identical to the con-struction of hydraulic cylinder 90 and servovalve 95, respectively, shown in Figures 8 and 9. The hydraulic cylinder 152 will therefore be considered to have a piston-end space ~
"L" and a rod-end space "i", and the same reference numerals ~ -, . .
` used in connection with hydraulic cylinder 90 and servovalve 95 will be used also in connection with hydraulic cylinder 152 and servovalve 151.
We shall consider the case when servomechanism 17 controls extension of the boom. Rod end space "i" of hydraulic ~;
~` cylinder 152 is connected to rod-end space "~" of hydraulic cylinder 8 which controls extension of the telescopic boom 1.
Duct 135 is connected to piston-end space "f" of cylinder 8 and duct 134 is connected to piston-end space "L" of hydraulic cylinder 152.
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~ s p~eviously descr;bed, anticlockwise turninc3 o~ the pivot 2 and boom 1 causes hydraulic cylinder 152 to mov~ to the riyht (in Figure 3) along rod 150.
Servovalve 151 is in the position shown in Figure 9, so that ducts 134 and 135 in comrnunication with spaces "L" and :.
"f", respectively, are closed so that working fluid is trapped in spaces "L" and "f". Thus, movement of the hydraulic cylinder 152 to the riyh-t is transmitted, by way of the working ~`
fluid trappedfluid trapped in space "L", to piston 96 and causes rod 93 attached to body 94 of servovalve 95 (i.e.
servovalve 151) to also move to the right. As a result of the ~ -movement of body 94 relative to plunger 132, duct 138 becomes connected to duct 135 and working fluid fed into servovalve g5 ~i.e. servovalve 156) through duct 138 flows into piston end space "f" of boom extending the con-trolled hydraulic cylinder 8 via duct 135. The telescopic boom 1 thus becomes extended.
As fluid flows into piston-end space "f" of cylinder 8, working fluid is forced out of rocl-end space "g" into rod-end space "i" of hydraulic cylinder 90 (i.e. hydrauliccylinder 152). Consequently piston 96 is moved to the left :~ . .
(in Figure 3 or 8) and restored to its initial position - (~igure 9).
`` When fluid is passing into rod-end space "i", fluid is forced out of piston-end space "L" along duct 134 and into the return duct 136, which has become connected to duct 134 . . -:
by the movement towards the right relative to plunger 132 of the body 94 of servovalve 35 (i.e. servovalve 151).
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In the same way, clockwise movement of the boom and pivot Z causes movement of body 94 of the left relative to plunger 132 (in Figure 8 or 9), the connection of duct 138 to duct 134 to supply working fluid to piston-end space "L" and ''; ' :-' ,A.
, ~ , , : ' , , ,:. ' ' ~3767 tl)e c:onnection of cl~lct 135 to duct 137 Eor return of working fluid from piston-elld space "f" of the controlled hydraulic cylinder 8 as the telescopic boom 1 contracts in lenyth.
Preferably, servomechanism 15 controls the extension of the telescopic boom by means of hydraulic cylinder 8 in response to lifting of the boom in a vertical planej whilst servomechanism 17 controls the axial extension of the feed bar by means of hydraulic cylinder 6 in response to turning of the boom in a horizontal plane.
It will be appreciated from the above description that the drilling boom assembly shown in the drawings may be operated both on an automatic cycle and in an independent control mode. This considerably extends the capabillties of the'drilling boom assembly.
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A known drilling boom assembly comprises a telescopic boom with an ac~uating hydraulic cylinder, said boom being hinged with its one end to a pivot mounted on a bearlng plate.
The boom can turn round its own axis. Hinged to a free end of the telescopic boom is-a feed bar with a drifter, said feed bar being provided with a hydraulic cylinder. Rigidly fixed to this free end of the telescopic boom is a head carrying hydraulic cylinders for til-ting and swivelling the feed bar in a horizontal plane as well as a rotational mechanism to turn the feed bar round the axis of -the rotational mechanism ' which axis is parallel to that of the feed bar.
Change of the angle of inclination of the telescopic boom in a vertical plane is accomplished by means of a hydraulic cylinder whose rod free end is hinged to the boom, while its body is articulated to the pivot.
Turning the telescopic boom in a horizon-tal plane is accomplished by means of a hydraulic cylinder whose rod free ; end is articulated to the bearing plate.
A disadvantage of the known drilling boom is that lifting or turning of the boom causes the distance between the feed ~ar and a rock face to vary. Also, the horizontal angle and .
the vertiGal angle of the feed bar with respect to the rock face become altered.
This occurs when lifting the telescopic boom in a vertical plane and turning the boom in a horizontal plane.
Alignment of the working end of the feed bar with the hole is a rather laborious and time-consuming operation.
It is an object of the present invention to provlde a drilling boom assembly that automatically compensates for '~
~37~
cleviation o~ the end of ~he manipu].ator fron~ the face, ~hile ~- swinginy the telescopic manipulator.
According to the present invention, there is provided ~: a drilling boom assembly comprising, a telescopic boom, the boom being expandable and contractable in lenyth and having a first end and a second end, the first end being hinged to a pivot mounted on a bearing plate, the pivot and the boom being pivotal relative to the bearing plate about a vertical axis, a first :
hydraulic cylinder assembly forming part of the boom for control- -~j 10 ling the length thereof, a feed bar hinged to the second end of ~ . :
``¦ the boom, the feed bar being provided with a drifter and having :
' a working end, the feed bar being axially movable forwards and ~' backwards relative to the second end of the boom by means of a second hydraulic cylinder assembly, the second hydraulic cylinder q ~ assembly being mounted on the second end of the boom, a third :, hydraulic cylinder assembly for tilting the feed bar in a vertical j plane, the third hydraulic cylinder assembly also being mounted on the second end of the boom, a fourth hydraulic cylinder assembly for turning the feed bar in a horizontal plane, the fourth hydraulic cylinder assembly also being mounted on the second . end of the boom, a mechanism for rotating the feed bar about an ~ axis parallel to the axis of the feed bar, a fifth hydraulic cylinder assembly for lifting the boom, one end of the fifth . hydraulic cylinder assembly being hinged to the boom, the other end of the fifth hydraulic cylinder assembly being hinged to the pivot, a sixth hydraulic cylinder assembly for turning the tele-~ ~:
: scopic boom in a horizontal plane, one end of the sixth hydraulic cylinder assembly being hinged to the bearing plate, the other end ` of the sixth hydraulic cylinder assembly bein~ hinged to the boom, - 30 a servomechanism for controlling operation of either the first or ~ alternatively the second hydraulic cylinder assembly, the cylinder assembly controlled by the servomechanism hereinafter being ,. .
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referred to as the controlled cylinder assembly, the servo-mechanism comprising a support rod, a seventh hydraulic cylinder assembly and a servovalve, one end of the seventh hydraulic cylinder assembly being connected to the pivot and the other end thereof being connected to the support rod each of the afore-mentioned hydraulic cylinder assemblies comprising a respective cylinder accommodating a piston defining a first variable volume space and a second variable volume space in the cylinder, the first variable volume space of the seventh hydraulic cylinder being in communication with the first variable volume space of . .
the cylinder of the controlled cylinder assembly, said communic-ating spaces being equal in volume at any one time, the servovalve comprising a body and a plunger accommodated in the body and attached to the rod, the body having a first duct for supply of working fluid to the servovalve, a second duct communicating with the second variable volume space of the controlled cylinder for supplying working fluid to that space and a third duct communic-ating with the second variable volume space of the seventh hydra-ulic cylinder for return of working fluid from that space, the plunger controlling communication ~etween the ducts, and a connec-ting means coupling the rod with the boom which causes the seventh hydraulic cylinder assembly and the body of the servovalve to displace with respect to the plunger, thus bringing the first duct into communication via the second duct with the second variable volume space of the controlled hydraulic cylinder assembly, thus `
either extending or retracting the controlled hydraulic cylinder assembly and compensating to maintain the working end of the feed bar in a desired vertical plane, when either (i) the controlled cylinder assembly is the first hydraulic cylinder assembly and the boom turns in a vertical plane or (ii) the controlled cylinder assembly is the second hydraulic cylinder assembly and the boom turns in a horizontal plane.
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371~7 It is expedient that the servomechanism drive be secured on the boom, with the piston-end space or rod-end space of the boom actuating hydraulic cylinder communicating ,1 ' .
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~3~ ;7 with the respect:ive rod-end s~!~ce or piston-end space of the servomechanism clrive hydraulic cylinder, and that thc connecting means include a slide block. tn this case vertical lifting of the boom will cause the slide block to move along the guideways to displace -the body of the servomechanism drive hydraullc cylinder.
It is also preferable that the servomechanism drive be secured on the bearin~ plate, with the piston-end space or rod-end space of the feed hydraulic cylinder communicating with the respective space of the servomechanism drive hydraulic cylinder. Preferably, the connecting means is provided with -; a tie rod hinged to the servomechanism drive hydraulic cylinder body, said connecting means being secured on a pivot by means .~ - .
of an arm. In this case horizontal turning of the boom causes the tie rod to move with respec-t to the axis of the pivot to displace the body of the servomechanism drive hydraulic cylinder.
drilling boom assembly embodying the invention is described below with reference to the accompanying drawings, wherein:
~ Figure 1 is a general schematic side view of the ,! drilling boom assembly, in a horizontal position (I)l in a lifted position (II) and in a lowered position (III).
I Figure 2 is a plan view of the drilling boom assembly of Figure 1, Figure 3 is a vertical elevation of a bearing plate carrying a pivot, a boom actuating hydraulic cylinder and a servomechanism drive;
Figure 4 is a longitudinaI, partly sectional, view 3Q of a boom of the drilling boom assembly of Figures 1 and 2;
Figure 5 is a cross-section taken along line V-V
in Figure 4;
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7~7 Figur~ 6 is a lonc~itllclinal sec-tional view of a hydraulic cylinder ~or controll:ing the lenc3th of ~he boom shown in Figure 4;
Figur~ 7 is a longitudinal sectional view of a hydraulic cylinder for lifting the boom through a vertical plane Figure 8 is a longitudinal sectional view of a drive of a servomechanism;
Figure 9 is a longitudinal sectional view of a valve of the servomechanism drive; and Figure 10 is a schematic representation of the drill-ing boom assembly of Figure 1.
The drilling boom assembly shown in the drawings icomprises a telescopic boom 1 (Figure 1). One end of the boom ~ -is secured on a pivot 2 which is mounted on a bearing plate 3 so that the pivo-t 2 together with the boom 1 may turn about a ver-tical axis l. A feed bar 4 is hinged to the end of the boom remote from the pivot 2, i.e. the free end of the boom.
The feed bar 4 is provided with a dr:ifter 5. The feed bar 4 - comprises a hydraulic cylinder 6 and i5 connected to a head 7 which is rigidly fixed to the free end of the boom. The boom 1 accommodates an actuating hydraulic cylinder 8. The head 7 is provided with a hydraulic cylinder 9 for tilting the feed bar 4 through a vertical plane and a hydraulic cylinder 10 ~Figure .~ 2) for turning the feed bar 4 through a horizontal plane. The ;~
head also carries a rotational mechanism 11 ~Figure 1) for rotating the feed bar 4 through an angle of up to 180 about an axis 23 parallel to the axis of the feed bar. Provision -~
of the rotational mechanism 11 makes it possible to carry out drilling operations to produce parallel holes in a rock face at a small distance from the rock walls and roof of a mine opening and, moreover, almost fully excludes a 'dead zone' on ~-. ~ .
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thc ~ace whe~ein drillillg is iml~ossible. ~ hydraulic cylinder 1.2 ~or :liEting !:he tc:l.escoE~ic boom through a vertical r~Lane is hinyed at one end to said boom. The other end of the hydraulic ; cylinder 12 is secured on the pivot 2 by means of a joint 13.
The drilling boom assembly also comprises a hydraulic cylinder 14 (Figure 2) for turning the telescopic boom in a horizontal plane.
The drilling boom assembly is provided with a servomechanism 15 for controlling operation of the hydraulic actuating cylinder 8 of -the boom. The servomechanism 15 comprises a drive 15a secured on the telescopic boom 1 and a - connecting means 16.
.:: The drilling boom assembly also carries a servo- .
mechanism 17 (Figure 3) which is similar.in design to the servomechanism 15 and is for controlling operation of the hydraulic cylinder 6 of the feed bar 4. The servomechanism 17 comprises a drive 17a secured on the bearing plate 3 and a connecting means 18 for connecting servomechanism 17 to pivot 2.
The telescopic boom 1 (Figure 4) is provided with an ~l 20 eye 19 and a groove "a" (Figure 1). The guideway 20 is rigidly .~ fixed to the pivot 2 and.forms part of the connecting means 16 l of the servomechanism 15. The guideway 20 slidingly supports :' ! a slide block 21 which is rigidly fixed to the hydraulic cylinder of the servomechanism and forms part of the connecting means 16. The telescopic boom comprises a body 22 (Figure 4).
The actuating hydraulic cylinder 8 incorporates bronze bushes .-' 23 and bronze liners 24 (Figures 4 and-5). A rod 25 of the -actuating hydraulic cylinder 8 is connected with the body 22 of the telescopic boom 1. The body 22 of the telescopic boom is coupled with a rod 26. The rod 25 is held against rotation about its own axi.s by means of keys 27 and 28 housed in grooves "b" and "c" of the body 22. The body 22 is provided with ~: - 6 -,, ~ ' . .
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as~embly ports "cl" (Figure 4) -lncl "e" tFigure 5) normally closed with cov~rs 29 (I~'icJure 4) and 30 (Figure 5).
The actuating hydraulic cylinder 8 comprises a body 8a. The body 8a (Fiyure 6) accommodates the rod 26. ~ piston 31 is fixed to the rod 26. A support 32 provided with an eye ; 32a is welded to the rod 26. A support 33 provided with an eye 33a is welded to the body 8a. Working fluid is fed to a piston-end space "f" of the cylinder and to a rod-end space "g"
-through respective inlets 34 and 35 provided in the support 32.
The working fluid is oil. Sealing of working spaces "f" and "g" is effected by means of collars 36, 37 and 38. The piston 31 on the rod 26 is sealed by means of rubber rings 39 and 40.
i From the inlet 34-the working fluid flows to the space "f" via -, a pipe 41 sealed with rubber rings 42 and 43. A bush 44 is held in the body 8a with the help of a rubber ring 46. Mud removers 47 and 48 are secured by means of a cover 49 and cotter pins 50 and 51.
The servomechanism 15 and 17 can be used in drilling boom assemblies of any type and, particularly, on drilling boom assemblies adap-ted to maintain paral:Lelism of the feed motion , and operating on the principle of hydraulic parallelogram.
As shown in Figure 7, the hydraulic cylinder 12 :1 !
comprises a pilot cylinder 52 employed in a hydraulic parallel-ogram circuit and a hydraulic cylinder 53 for lifting the telescopic boom-in a vertical plane. Rods 54 and 55 of hydraulic cylindars 52 and 53 are interconnected by means of nut 56 fixed on the rod 55 with a cotter pin 57 retaining said nut against spontaneous unscrewing. Pistons 58 and 59 are secured on the rods 54 and 55. Sealing of the spaces of the hydraulic cylinder 52 is effected by means of collars 60 to 66 and rubber rings 67 -to 73. A bush 74 is held in a body 75 by means ; of a snap ring 76. Mud removers 77 and 78 are retained with a ~'`
, 3~ 7 cove~r 79 and cotter pins 80 an~l 81. A bush 82 is secured between thc body 75 and a body 83 which are interconnecte~ h bolts ~4 and ~5. Rod-end and piston-end spaces of the pilot cylinder 52 are hydraulically intercommunicated through connections 86 and 87 with the respective spaces of the hydra-ulic cylinder 9 (Figure 1) for tilting through a vertical plane the feed bar 4 and are equal in volume with the spaces of the hydraulic cylinder 9.
The hydraulic cy]inder 12 for lifting the telescopic boom 1 and the hydraulic cylinder 9 for tilting the feed bar 4 thus operate in unison. Thus, the inclination of the feed bar 4 always remains the same, irrespective of the inclination of the boom 1 to the vertical, i.e. said cylinders ensure operation of a "hydraulic parallelogram."
The drive 15a of the servomechanism 15 is secured on the body 22 of the telescopic boom 1 by means of brackets 88 ~' .
and 89 (Figure 8). The drive 15a comprises a hydraulic cylinder 90 having a body 91 connected with tlle slide block 21 (Figure 1) through a dowel pin 92. A piston-end space "h" and a rod-end space "i" are defined within the hydraulic cylinder 90. The ~ rod end space "i"isin-ommunication with the rod-end space "g" ~ -i (Figure 6) of the actuating hydraulic cylinder 8 of the tele- ~
;, : , scopic boom 1. The rod-end space "i" of the hydraulic cylinder 90 and the rod-end space "g" of the hydraulic cylinder 8 are equal in volume at any one time. A servo-valve 95 has a body :. ~.
94 secured on the free end of a rod 93 (Figure 8) of the hydraulic cylinder 90. The body 91 of the hydraulic cylinder 90 accommodates a piston 96 provided with rings 97 and 98 and secured on the rod 93 by a nut 99. A cover 100 of the -hydraulic cylinder 90 is fixed in the body 91 by means of a snap ring 101, a washer 102, and bolts 103 and 104. Sealing of the spaces along the rod 93 is effected by means of collars A
.
376i'7 I05 to 10~ and rubber rings ll() to 112. Mud removers 113 ancl 114 are secured in the body 91 by means of a cover 115 and cotter pins 116 and 117. Mud removers 118 and 119 are secured in the body 91 hy means of the cover 100 and the washer 102.
The hydraulic cylinder 90 comprises connections 120 and 121.
cover 122 of the servo-valve 95 accommodates a collar 123 and mud removers 124 and 125 fixed by means of a cover 126 and cotter pins 127 and 128. The body 94 of the servo-valve 95 is sealed by means of rubber rings 129 and 130, said body being ~ 10 provided wi-th a connection 131 for feeding the working fluid ; into the servo-valve. The servo-valve 95 comprises a ~lunger 132 mounted on a rod 133.
`~ The body 94 (Figure 9) is provided with a duct 134 -to feed working fluid into the piston-end space "h" (Figure 8) of the hydraulic cylinder 90 of the drive 15_ of the servo-mechanism 15, a duct 135 (Figure 9) to feed the working fluid , into the rod-end space "f" (Figure 10) of the actuating hydraulic cylinder 8, ducts 136 and 137 (Figure 9) to return the working fluid Erom said spaces "h" and "f" respectively and -~
` 20 a duct 138 to feed the working fluid into the servo-valve 95.
The plunger 132 has a shoulder 139 which together with springs : .
~ 140 and 141 and washers 142 and 143 retain the plunger 132 in j ! a fixed position with respect to the rod 133. The washers 142and 143 bear against a shoulder 144 of a bush 145 coupling together two rods 146 and 147 housed-in the rod 133 (Figures 8 and 9).
The servome-chanism 17 (Figure 3) is intended to maintain constant the horizontal distance of the feed bar 4 (Figure 2) rock from the vertical rock face when turning the telescopic boom 1 and feed bar 4 in a horizontal plane. The servomechanism 17 is connected with the extending hydraulic cylinder 6. The drive 17a (Figure 3) of the servomechanism 17 ~
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~3~7i~7 is secured on the bearin~ plat~ 3 not shown, by means of brackets 148 and 149 and is provided with a rod 150, coaxially mounted on which are a servo-valve 151 and a hydraulic cylinder 152 having a body 153 connected with a tie rod 155 of the connectinc~ means 18 through a hinged joint 154. The -tie rod 155 is pivotally connected through a joint 156 with an arm 157 rigidly secured on the pivot 2. The body 153 is held against rotation around its longitudinal axis with the help of a roller 158 mounted on the bearing plate 3 and located in a groove "j"
of the body 153.
The rod-end space of the hydraulic cylinder 152 of the drive 17a communicates with the rod-end space of the ; extending hydraulic cylinder 6 (Figure 1) of the feed bar 4 and is equal in volume at any one time with the rod-end space of cylinder 6.
The drilling boom assembly is associated with a control desk (not shown) having distributors 159, 162 and 163 (Figure 10). The distributors 159, 162 and 163 are connected ; to a working fluid line (not shown).
The drilling boom assembly shown in the drawings operates as follows.
When opera-ting in a mode which allows for automatic maintainance of the distance of the feed bar 4 from a vertical rock face despite lifting of the boom, the distributor 163 is put into operation. If the duct 138 is closed by the plunger 132 and cannot communicate with ducts 134, 135 (Figure 9) working fluid cannot flow into the hydraulic cylinder 8 of the telescopic boom 1.
` To make the telescopic boom 1 move vertically, the ; 30 distributor 159 (Figure 10) is operated with the distributor 163 turned on. Working fluid from a working fluid line (not shown) is fed through the distributor 159 into the piston-,,~ ", ., :' .
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~ c "k" or in~o thc r~l-cnd sE)~ce "I" o~ Wle hy~raulic cyLinder 12.
Upon fe~in~J tlle ~rking flui.d into ~he piston-end space "k" of the hydrauli.c cylinder 12, the rod 55 is displaced and turns the telescopic boom anti-clockwise wlth resp~ct to the bearinc3 plate 3. ~s a result, the slide block 21 of the connecting means 16 of the servcmechanism 15, sliding up along the guideway 20, displaces the hydraulic cylinder 90 and, due to the fluid trapped in spaces "h" and "i", the body 94 (Figure 8) of the servo-valve 95 relative to the plunger 132 towards the bracket 89. Consequently working fluid from the working fluid line flows along the duct 138 into . 10 the duct 135 communicated with the piston-end space "f" oE the hydraulic cylinder 8, thus extending the latter and increasing the leng-th of the telescopic boom 1. Slmultaneously, -the space "h" of the hydraulic cylinder 90 comes into cGmmunication through the duct 134 with the duct 136 which i.s in communication with a return line through a pipeline 161. As the - :
hydraulic cylinder 8 extends, the working fluid expelled from the rod-end space "g" of the hydraulic cylinder 8 flows into the rod-end space "i" of the hydraulic cylinder 90 along the pipeline 160 and displaces the cylinder rod 93 (Figure 8~ which is connec-tecl to the body 34 of the servo-valve 95, relative to the plunger 132, towards the bracket 88. As a 20. result, the plunger 132 returns to the position shown in Figure 9 and the duct 138 and becornes closed once again. Thus, working fluid ceases flowing . to the duct 135 and to the piston-end space "f" of the hydraulic cylinder -;
8. Consequently, the telescopic boom is extended a length enough to co~ensate for the horizontal deviation of the end of the boom 1 away from the rock face due to the anti-clockwise moverrent of the boom; which makes it possible to drill holes whose ends are located in the s~r.e vertical plane.
. The inclination of the feed bar to the vertical is retained by rneans of the hydraulic cylinder 9 which operates together with cylinder 12 in a hydraulic parallelogram (Figure ' ~;
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10). Ul~on Eeeding the workinc~ fluid into the rod-piston space "1" of the hydraulic cylinder 12, the telescopic bcom 1 ~urns clockwise and c3ets shorter correspondingly.
When operating at a rock face, conditions may arise which require not only automatic but also independent control of the boom length and its vertical swivel. An example is found under conditions which require the change of the length of the telescopic boom without altering its angle of elevation, or vertical swivel of the drilling boom assembly with the telescopic boom length unchanged.
Provision of independent control of both the length of the telescopic boom and its vertical swivel is attained in the drilling boom assembly by virtue of servo-valves available on the con-trol desk and the springs 140 and 141 in the servo- -~ ;
valve 95, due to which the plunger displacement is relatively ~;
inconsiderable during lengthy displacement of the servopiston ~ body.
; Such independent control can occur only when the servo-valve of the servomechanism dr:ive 15a controlling the length of the boom is disconnected from -the oil line. In order to operate in an independent control mode, the distributor 163 ` (loca-ted on the control desk) for feeding the working fiuid to the servo-valve 95 of the servomechanism drive 15a is ~ ~
turned off. When the servo-valve 95 is disconnected from the ~-oil line, vertical lifting of the telescopic boom l causes -the servo-valve 95 to displace with respect to-the plunger 132, and thus the telescopic boom remains retracted. With the drilling boom assembly operating in an independent control mode, the telescopic boom may be lifted by means of the dis-tributor 159 located on the control desk.
The working rluid is fed to piston-end space "k"
of the hydraulic cylinder 12 by means of the distributor 1~9.
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~; a r~n~uLt, th~! rod 55 eY~en~s and causes the telescopic boom 1 to turn counter-clockwise with respect to the p;vot 2.
The slide block 21 moves up the guideway 20 and displaces the cylinder 90 together with the body 94 of the servor-valve 95 with respect to the plunger 132 till the butt end of the plunger 132 comes in contact with -the butt end of the rod 93 (see Figure 9). Then the body 94 of ~he servo-valve 95 con-tinues to displace towards the bracket 89 together with the plunger 132 whose collar 139 also displaces the washer 143 towards the bracket 89, thereby compressing the spring 141.
Upon feeding the working fluid into the rod-end space "1" of the hydraulic cylinder 12 (Figure 10), the tele-` scopic boom 1 turns clockwise.
~ ~ When operating in an independent control mode, the `~ telescopic boom 1 may be extended by actuating the distributor 162 (Figure 10) located on the control desk. As a result, the working fluid is fed through the distirbutor into the piston-., :
i end space "f" of the hydraulic cylinder 8 whose rod 25 ge-ts e~tended, thus increasing the length of the telescopic boom 1.
The working fluid expelled from the rod-end space "g" is fed ` through the hydraulic pipeline 160 into the rod-end space "i"
of the hydraulic cylinder 90 and urges the rod 93 together with the body 94 of the servo-valve 95 and the plunger 132 to displace towards the bracket 88, thus compressing the left-hand spring 140 (Figùre 9)-. As a result, the space "h" of the hydraulic cylinder 90 (Figure 10) of the servomechanism 15a is communicated with the return line through the distributor i62.
Upon retracting the telescopic boom the working fluid is fed through -the distributor 162 into the piston-end space "h" of the hydraulic cylinder 90. As a result, the rod 93 together with the body 94 of the servo-valve 95 and the ,.~
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37~;'7 ngcr 1.32 are displaced tow~r.cls the bracket 89, thus com-pressing the ri.cJht-hand spring 1~1 (Figure 9). The workiny ~luid e~pelled from the rod-end space "i" is fed through the hydraulic cylinder 160 into the rod-end space "g" of the hydraulic cylinder 8. As a result, the rod 25 retracts into the hydraulic cylinder 8, thus decreasing the length of the telescopic boom 1.
When changing over from an independent control of operation to an automatic one, working fluid is fed through 10 -the distributor 163, and the servo-valve 95 of the servo-mechanism drive 15a into the actuating cylinder 8. ~s a result, the springs 140 and 141 of the servo-valve 95 are set to the initial position (see Figure 9). ~:
~ The drive 15_ of the servomechanism 15 coupled w.ith the actuating hydraulic cylinder ~ o:E the telescopic bo.om 1 ; and the drive 17a of the servomechanism 17 coupled with the hydraulic cylinder 6 of the feed bar 4 are similar in design, therefore when discussing the operation of the servomechanism 17, reference is directed to the constructional units as shown in Figures ~ and 9 and to the reference numerals in the accompanying drawings.
The o~eration of the servomechanism 17 is entire ! analogous.to the mode of operation of the servomechanism 15, which has already been described. However, whilst the servomechanism I5 controls the degree of extension of tele~
scopic boom 1 in response to lifting of the boom in a vertical ~ plane, the servo-mechanism 17 controls the degree of extension of the telescopic boom 1 in response to tuning of the boom i.n a horizontal plane. Just as the servomechanism 15 could : 30 alternatively be used to control axial movement of the feed '1 bar 4 by means of the second hydraulic cylinder 6, so as to maintain the working end of the feed bar at a constant . .
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7~7 l1stance ~rom a vertical rock ~ace, so the servomechanism 17 may also alternatively control the second hydraulic cy]inder 6.
As the boom 1 attached to pivot 2 booms in a horizontal plane, the hydraulic cylinder 152 is moved by the connecting means 1~ along the rod 150. The rod 150 is rigidly fixed by means of brackets 148 and 149 to bearing plate 3.
Thus, for example, anticlockwise turning of the pivot 2 (considered from above in Figure 3) is converted by means of arm 157 on the pivot 2, tie tod 155 and hin~ed join-t 54 into axial movement of hydraulic cylinder along the rod towards the right hand side in Figure 3.
The construction of hydraulic cylinder 152 and , servovalve 151 (Figure 3) is converted by means of arm 157 on the,pivot 2, tie rod 155 and hinged joint 154 into axial !movement of hydrualic cylinder along the rod towards the right hand side in Figure 3.
The construction of hydrau:Lic cylinder 152 and servo-valve 151 (Figure 3) is substantially identical to the con-struction of hydraulic cylinder 90 and servovalve 95, respectively, shown in Figures 8 and 9. The hydraulic cylinder 152 will therefore be considered to have a piston-end space ~
"L" and a rod-end space "i", and the same reference numerals ~ -, . .
` used in connection with hydraulic cylinder 90 and servovalve 95 will be used also in connection with hydraulic cylinder 152 and servovalve 151.
We shall consider the case when servomechanism 17 controls extension of the boom. Rod end space "i" of hydraulic ~;
~` cylinder 152 is connected to rod-end space "~" of hydraulic cylinder 8 which controls extension of the telescopic boom 1.
Duct 135 is connected to piston-end space "f" of cylinder 8 and duct 134 is connected to piston-end space "L" of hydraulic cylinder 152.
:
.
:-:: . . ~
-.: . ' '.,: ~ ~ ' 3~
~ s p~eviously descr;bed, anticlockwise turninc3 o~ the pivot 2 and boom 1 causes hydraulic cylinder 152 to mov~ to the riyht (in Figure 3) along rod 150.
Servovalve 151 is in the position shown in Figure 9, so that ducts 134 and 135 in comrnunication with spaces "L" and :.
"f", respectively, are closed so that working fluid is trapped in spaces "L" and "f". Thus, movement of the hydraulic cylinder 152 to the riyh-t is transmitted, by way of the working ~`
fluid trappedfluid trapped in space "L", to piston 96 and causes rod 93 attached to body 94 of servovalve 95 (i.e.
servovalve 151) to also move to the right. As a result of the ~ -movement of body 94 relative to plunger 132, duct 138 becomes connected to duct 135 and working fluid fed into servovalve g5 ~i.e. servovalve 156) through duct 138 flows into piston end space "f" of boom extending the con-trolled hydraulic cylinder 8 via duct 135. The telescopic boom 1 thus becomes extended.
As fluid flows into piston-end space "f" of cylinder 8, working fluid is forced out of rocl-end space "g" into rod-end space "i" of hydraulic cylinder 90 (i.e. hydrauliccylinder 152). Consequently piston 96 is moved to the left :~ . .
(in Figure 3 or 8) and restored to its initial position - (~igure 9).
`` When fluid is passing into rod-end space "i", fluid is forced out of piston-end space "L" along duct 134 and into the return duct 136, which has become connected to duct 134 . . -:
by the movement towards the right relative to plunger 132 of the body 94 of servovalve 35 (i.e. servovalve 151).
;
In the same way, clockwise movement of the boom and pivot Z causes movement of body 94 of the left relative to plunger 132 (in Figure 8 or 9), the connection of duct 138 to duct 134 to supply working fluid to piston-end space "L" and ''; ' :-' ,A.
, ~ , , : ' , , ,:. ' ' ~3767 tl)e c:onnection of cl~lct 135 to duct 137 Eor return of working fluid from piston-elld space "f" of the controlled hydraulic cylinder 8 as the telescopic boom 1 contracts in lenyth.
Preferably, servomechanism 15 controls the extension of the telescopic boom by means of hydraulic cylinder 8 in response to lifting of the boom in a vertical planej whilst servomechanism 17 controls the axial extension of the feed bar by means of hydraulic cylinder 6 in response to turning of the boom in a horizontal plane.
It will be appreciated from the above description that the drilling boom assembly shown in the drawings may be operated both on an automatic cycle and in an independent control mode. This considerably extends the capabillties of the'drilling boom assembly.
~`
., .
.
.~ ' ' ' . ~,.
', ' . , ~ 17 ~
~a~L
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A drilling boom assembly comprising, a telescopic boom, the boom being expandable and contractable in length and having a first end and a second end, the first end being hinged to a pivot mounted on a bearing plate, the pivot and the boom being pivotal relative to the bearing plate about a vertical axis, a first hydraulic cylinder assembly forming part of the boom for controlling the length thereof, a feed bar hinged to the second end of the boom, the feed bar being provided with a drifter and having a working end, the feed bar being axially movable forwards and backwards relative to the second end of the boom by means of a second hydraulic cylinder assembly, the second hydraulic cylin-der assembly being mounted on the second end of the boom, a third hydraulic cylinder assembly for tilting the feed bar in a vertical plane, the third hydraulic cylinder assembly also being mounted on the second end of the boom, a fourth hydraulic cylinder assembly for turning the feed bar in a horizontal plane, the fourth hydraulic cylinder assembly also being mounted on the second end of the boom, a mechanism for rotating the feed bar about an axis parallel to the axis of the feed bar, a fifth hydraulic cylinder assembly for lifting the boom, one end of the fifth hydraulic cylinder assembly being hinged to the boom, the other end of the fifth hydraulic cylinder assembly being hinged to the pivot, a sixth hydraulic cylinder assembly for turning the telescopic boom in a horizontal plane, one end of the sixth hydraulic cylinder assembly being hinged to the bearing plate, the other end of the sixth hydraulic cylinder assembly being hinged to the boom, a servomechanism for controlling operation of either the first or alternatively the second hydraulic cylinder assembly, the cylinder assembly controlled by the servomechanism hereinafter being referred to as the controlled cylinder assembly, the servomechanism comprising a support rod, a seventh hydraulic cylinder assembly, and a servovalve, one end of the seventh hydraulic cylinder assembly being connected to the pivot and the other end thereof being connected to the support rod each of the aforementioned hydraulic cylinder assemblies comprising a respec-tive cylinder accommodating a piston defining a first variable volume space and a second variable volume space in the cylinder, the first variable volume space of the seventh hydraulic cylinder being in communication with the first variable volume space of the cylinder of the controlled cylinder assembly, said commun-icating spaces being equal in volume at any one time, the servo-valve comprising a body and a plunger accommodated in the body and attached to the rod, the body having a first duct for supply of working fluid to the servovalve, a second duct communicating with the second variable volume space of the controlled cylinder for supplying working fluid to that space and a third duct communicating with the second variable volume space of the seventh hydraulic cylinder for return of working fluid from that space, the plunger controlling communication between the ducts, and a connecting means coupling the rod with the boom which causes the seventh hydraulic cylinder assembly and the body of the servovalve to displace with respect to the plunger, thus bringing the first duct into communication via the second duct with the second variable volume space of the controlled hydraulic cylinder assembly, thus either extending or retracting the controlled hydraulic cylinder assembly and compensating to maintain the work-ing end of the feed bar in a desired vertical plane, when either (i) the controlled cylinder assembly is the first hydraulic cylinder assembly and the boom turns in a vertical plane or (ii) the controlled cylinder assembly is the second hydraulic cylinder assembly and the boom turns in a horizontal plane.
2. A drilling boom assembly according to claim 1, wherein the controlled cylinder assembly is the first hydraulic cylinder assembly, and wherein the servomechanism rod is secured on the boom, the connecting means is provided with a slide block which is rigidly connected with the cylinder of the seventh hydraulic cylinder assembly, and a guideway secured on the pivot, said guideway slidably engaging said slide block, vertical swivelling of the boom causing the slide block to move along the guideway together with the cylinder of the seventh hydraulic assembly cylinder.
3. A drilling boom assembly according to claim 1, wherein the controlled cylinder assembly is the second hydraulic cylinder assembly and wherein the rod is secured on the bearing plate, the connecting means comprises a tie rod hinged to the cylinder of the seventh hydraulic cylinder assembly, an arm is secured on the pivot and hinged to the tie rod, displacement of the telescopic boom in a horizontal plane resulting in displace-ment of the cylinder of the seventh hydrate cylinder assembly.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA234,452A CA1043767A (en) | 1975-08-29 | 1975-08-29 | Drilling boom |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA234,452A CA1043767A (en) | 1975-08-29 | 1975-08-29 | Drilling boom |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1043767A true CA1043767A (en) | 1978-12-05 |
Family
ID=4103933
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA234,452A Expired CA1043767A (en) | 1975-08-29 | 1975-08-29 | Drilling boom |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1043767A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107178317A (en) * | 2017-06-29 | 2017-09-19 | 中国煤炭科工集团太原研究院有限公司 | A kind of intelligent drilling cramp |
| CN109403875A (en) * | 2018-12-10 | 2019-03-01 | 湖南五新隧道智能装备股份有限公司 | A kind of drill boom and the drill jumbo with the drill boom |
-
1975
- 1975-08-29 CA CA234,452A patent/CA1043767A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107178317A (en) * | 2017-06-29 | 2017-09-19 | 中国煤炭科工集团太原研究院有限公司 | A kind of intelligent drilling cramp |
| CN107178317B (en) * | 2017-06-29 | 2023-09-12 | 中国煤炭科工集团太原研究院有限公司 | Intelligent drill frame |
| CN109403875A (en) * | 2018-12-10 | 2019-03-01 | 湖南五新隧道智能装备股份有限公司 | A kind of drill boom and the drill jumbo with the drill boom |
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