EARTH BORING MACHINE AND METHOD
United States Patent 3861748
The machine frame is mounted onto a lower portion of an expandable forward support ring for sideways pivotal movement of the frame and the cutterhead carried thereby about an axis which is generally parallel to the centerline of the tunnel. The cutterhead cuts a circle which is generally equal in diameter with the support ring. A steering link extends laterally of the tunnel and is connected at one of its ends to the frame and at its opposite end to the support ring. It is used for tilting the cutterhead sideways, so as to offset the cutterhead from the support ring, to in that manner change the course of the tunnel.
US Patent References:
Hydraulic circuit for holding and pushing cylinders of tunneling machine
Scaravilli et al. - December 1968 - 3419311
TUNNEL-BORING MACHINE
Winberg - August 1971 - 3598445
RAISE BORING MACHINE
Lauber - October 1972 - 3695718
Hydraulic circuit for holding and pushing cylinders of tunneling machine
Scaravilli et al. - December 1968 - 3419311
TUNNEL-BORING MACHINE
Winberg - August 1971 - 3598445
RAISE BORING MACHINE
Lauber - October 1972 - 3695718
Application Number:
05/440695
Publication Date:
01/21/1975
Filing Date:
02/08/1974
View Patent Images:
Export Citation:
Assignee:
The Robbins Company (Seattle, WA)
Primary Class:
Other Classes:
175/61, 299/31, 175/76
International Classes:
E21D9/10; E21C35/08
Field of Search:
299/10,31,33 175/62,61,73,76 61/85
Primary Examiner:
Purser, Ernest R.
Assistant Examiner:
Pate III, William F.
Attorney, Agent or Firm:
Graybeal, Barnard, Uhlir & Hughes
Claims:
What is claimed is
1. An axially advanceable tunnel boring machine, comprising:
2. A tunneling boring machine according to claim 1, wherein the support ring includes means for frictionally gripping the tunnel wall, to anchor such support ring in place within the tunnel.
3. A tunneling boring machine according to claim 1, wherein said support ring comprises at least two sections which are interconnected by an expandable link which is adjustable to expand and contract the support ring, such support ring being expandable outwardly into frictional engagement with the walls of the tunnel.
4. A tunneling machine according to claim 3, wherein said support ring includes at least two sections which are hinged together at and by the means which pivotally connects the frame to the support ring, and said support ring further includes means for swinging said sections outwardly into frictional contact with the wall of the tunnel.
5. A tunneling boring machine according to claim 1, wherein said means for tilting said frame from said support ring, and for adjustable affixing such frame in position relative to said support ring, comprises a double-acting hydraulic cylinder which extends transversely of the tunnel and is connected at one of its ends to the frame and at its other end to the support ring.
6. A tunneling machine according to claim 1, wherein said frame also includes an elongated beam portion which extends rearwardly from the cutterhead support, and wherein said means advancing said machine includes a gripper assembly spaced rearwardly from said cutterhead support and including laterally extendible and retractable gripper pad means, guide means for said beam portion mounting said gripper assembly for longitudinal back-and-forth movement along said beam portion, and propulsion ram means interconnected between said gripper assembly and the frame in the vicinity of said cutterhead support.
7. A tunneling machine according to claim 6, wherein said gripper assembly includes means mounting the gripper pad means for vertical, roll and yaw movement relative to the beam portion.
8. A tunneling machine according to claim 6, wherein said support ring includes means for frictionally gripping the tunnel wall, to anchor such support ring in place within the tunnel.
9. A tunneling machine according to claim 6, wherein said support ring comprises at least two sections which are interconnected by an expandible link which is adjustable to expand and contract the support ring, such support ring being expandable outwardly into frictional engagement with the walls of the tunnel.
10. A tunneling machine according to claim 9, wherein said support ring includes at least two sections which are hinged together at and by the means which pivotally connects the frame to the support ring, and said support ring further includes means for swinging said sections outwardly into frictional contact with the wall of the tunnel.
11. A method of steering a tunnel boring machine of a type having a single rotating cutterhead at its forward end which carries cutter means for dislodging material from the tunnel face as the cutterhead is both rotated and advanced axially forwardly, said method comprising:
1. An axially advanceable tunnel boring machine, comprising:
2. A tunneling boring machine according to claim 1, wherein the support ring includes means for frictionally gripping the tunnel wall, to anchor such support ring in place within the tunnel.
3. A tunneling boring machine according to claim 1, wherein said support ring comprises at least two sections which are interconnected by an expandable link which is adjustable to expand and contract the support ring, such support ring being expandable outwardly into frictional engagement with the walls of the tunnel.
4. A tunneling machine according to claim 3, wherein said support ring includes at least two sections which are hinged together at and by the means which pivotally connects the frame to the support ring, and said support ring further includes means for swinging said sections outwardly into frictional contact with the wall of the tunnel.
5. A tunneling boring machine according to claim 1, wherein said means for tilting said frame from said support ring, and for adjustable affixing such frame in position relative to said support ring, comprises a double-acting hydraulic cylinder which extends transversely of the tunnel and is connected at one of its ends to the frame and at its other end to the support ring.
6. A tunneling machine according to claim 1, wherein said frame also includes an elongated beam portion which extends rearwardly from the cutterhead support, and wherein said means advancing said machine includes a gripper assembly spaced rearwardly from said cutterhead support and including laterally extendible and retractable gripper pad means, guide means for said beam portion mounting said gripper assembly for longitudinal back-and-forth movement along said beam portion, and propulsion ram means interconnected between said gripper assembly and the frame in the vicinity of said cutterhead support.
7. A tunneling machine according to claim 6, wherein said gripper assembly includes means mounting the gripper pad means for vertical, roll and yaw movement relative to the beam portion.
8. A tunneling machine according to claim 6, wherein said support ring includes means for frictionally gripping the tunnel wall, to anchor such support ring in place within the tunnel.
9. A tunneling machine according to claim 6, wherein said support ring comprises at least two sections which are interconnected by an expandible link which is adjustable to expand and contract the support ring, such support ring being expandable outwardly into frictional engagement with the walls of the tunnel.
10. A tunneling machine according to claim 9, wherein said support ring includes at least two sections which are hinged together at and by the means which pivotally connects the frame to the support ring, and said support ring further includes means for swinging said sections outwardly into frictional contact with the wall of the tunnel.
11. A method of steering a tunnel boring machine of a type having a single rotating cutterhead at its forward end which carries cutter means for dislodging material from the tunnel face as the cutterhead is both rotated and advanced axially forwardly, said method comprising:
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to earth boring machines, and in particular to machine and method aspects of driving a large head boring machine along a curve.
2. Description of the Prior Art
Examples of known earth boring machines which are advanced by thrust rams which react rearwardly against a gripper assembly are shown by U.S. Pat. No. 3,061,287, granted Oct. 30, 1972, to James S. Robbins; by U.S. Pat. No. 3,203,737, granted Aug. 31, 1965 to Richard J. Robbins, Douglas F. Winberg and John Galgoczy; by U.S. Pat. No. 3,295,892, granted Jan. 3, 1967, to Douglas F. Winberg and John Galgoczy; by U.s. Pat. No. 3,383,133, granted May 14, 1968 to Victor J. Scaravilli and Charles J. Delisio and by U.S. Pat. No. 3,598,445, granted Aug. 10, 1971 to Douglas F. Winberg.
It is known to horizontally turn a boring machine of the above described type by rolling or tilting its frame sideways about its forward lower point of support floor, so as to horizontally offset the course of the cutterhead. The mechanism used for tilting the frame comprised a pair of substantially quarter-circular shoes which are located on opposite sides of the machine. The shoes were pivotally connected at their lower ends to a lower central portion of the cutterhead support. Such shoes projected upwardly from their pivotal connections and extended along the curved lower portions of the tunnel. A double-acting hydraulic cylinder was interconnected between the upper end of each shoe and an adjacent part of the cutterhead support. The machine was tilted by a shortening of the cylinder on the side of the machine towards which the machine is to be turned and a corresponding lengthening of the opposite side cylinder. The machine included an overhead shield basically like the one disclosed by the aforementioned U.s. Pat. No. 3,295,892. It was necessary to retract such shield from the tunnel roof before the machine could be tilted sideways. As a result the roof support was lost during turning.
SUMMARY OF THE INVENTION
The tunnel boring machine of this invention includes means for tilting the cutterhead sideways relative to a forward support ring in the tunnel, for the purpose of changing the course of the tunneling machine without a loss of roof support.
In preferred form, the boring machine of this invention comprises a main frame having a forwardly positioned cutterhead support and an elongated beam which extends rearwardly in the tunnel from the cutterhead support. A gripper assembly is spaced rearwardly of the cutterhead support. Thrust rams for shoving the boring machine forwardly relative to the gripper assembly are interconnected between the gripper assembly and the frame. The frame is supported at its forward end by an expandable support ring. The frame is pivotally connected to the support ring, preferably at the base of the ring, and an adjustable link is provided between the cutterhead support and the support ring, for tilting the cutterhead support, and hence the cutterhead carried thereby, sideways relative to the support ring, for the purpose of changing the course of the boring machine.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an isometric view taken from up above, looking towards the front and one side of the basic components of an embodiment of the tunneling machine of this invention, with some parts cut away for clarity of illustration of other parts;
FIG. 2 is the side elevational view of the tunneling machine, with some components shown in section;
FIG. 3 is a cross-sectional view through the tunneling machine, taken substantially along line 3--3 of FIG. 2;
FIG. 4 is a cross-sectional view taken through the tunneling machine, substantially along line 4--4 of FIG. 2;
FIG. 5 is a cross-sectional view taken through the tunneling machine, substantially along line 5--5 of FIG. 2;
FIG. 6 is a sectional view through the gripper assembly, taken substantially along line 6--6 of FIG. 4;
FIG. 7 is a top plan view showing the tunneling machine at the end of a straight section of tunnel and about to enter a curve;
FIG. 8 is a view like FIG. 7, but showing the tunneling machine moved into the curve; and
FIG. 9 is a view like FIGS. 7 and 8, but showing the tunneling machine moved an additional amount into the curve.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the several figures of the drawing, the illustrated embodiment comprises a support ring 10 which supports the forward portion of a frame 12. Frame 12 comprises a cutterhead support 14 and an elongated beam 16 which trails rearwardly from cutterhead support 14. A rotary cutterhead 18 is mounted for rotation on the cutterhead support 14. Small drive gears 22 driven by motors 20 mesh with a large diameter gear 24 on the cutterhead 18. Cutter elements 26 on cutterhead 18 dislodge material from the tunnel face and scoops 28 pick up the material and start it along a rearward course. The material is moved through the cutterhead 18 and onto a conveyor which is housed in the main beam 16, for example, as shown by U.S. Pat. No. 3,640,077, granted Feb. 8, 1972, to Frank George Watson and David Burnett Sugden.
The mechanism which advances the boring machine forwardly in the tunnel includes a gripper assembly which is basically like the gripper assembly disclosed by the aforementioned U.S. Pat. No. 3,203,737.
The gripper assembly 30 may comprise a gripper carrier 32 having a transverse passageway 34 formed therein in which two collinear gripper cylinders 36, 38 are housed. The cylinders 36, 38 comprise piston chambers which are rigidly connected together at their closed ends by upper and lower beam members 40, 42. A piston, one of which is designated 44, is located within each cylinder 36, 38. Piston rods 46, 48 extend outwardly from the pistons (44) and at their outer ends are connected to tunnel wall engaging gripper pads 50, 52.
Referring to FIG. 6, a trunion member 54 extends between the two sides of support 32 and is mounted at its ends for rotation about an axis X which is generally directed axially of the tunnel. A pin 56 extends perpendicularly through the trunion member 54. Pin 56 extends between, and at its ends is anchored to, the two beam members 40, 42, and is rotatable relative to member 54. Owing to this arrangement the trunion member 54 and the carrier 32 are rotatable as a unit about the axis of pin 56, i.e. axis Z (FIG. 4), within the limits of the space 34.
Gripper carrier 32 includes a pair of opposed slide bearings 58, 60 which receive and guide edge portions of a rail 62 which is part of the beam 16. A pair of double-acting hydraulic cylinders 64, 66 are interconnected between upper portions of the carrier 32 and the bodies of the cylinders 36, 38 (FIG. 4). Pivotal connections are provided at each end of the cylinders 64, 66. The cylinders 64, 66 constitute adjustable torque transfer links between the frame 12 and the gripper assembly 30, as will hereinafter be explained in greater detail.
Referring to FIG. 6, the gripper carrier 32 includes four corner placed springs 68 which function to automatically center the cylinders 36, 38 with respect to the carrier 32. The compression springs 68 react against pads 70 which make sliding contact with the side wall of the cylinder housings.
In the conventional manner, a pair of double-acting hydraulic thrust rams or cylinders 72, 74 are interconnected between the gripper pads 50, 52 of the gripper assembly 30 and forward portions of the frame 12, in the vicinity of the cutterhead support 14.
FIG. 1 shows the boring machine at the start of an advance. The gripper cylinders 36, 38 are extended, forcing the gripper pads 50, 52 outwardly into gripping contact with opposite side wall portions of the tunnel. Hydraulic fluid is delivered into the thrust rams 72, 74 to cause their extension. As they extend they react rearwardly against the gripper assembly 30 and shove the frame 12, and the cutterhead 18 carried thereby, axially forwardly against the tunnel face. At the same time the motors 20 are operated to rotate the cutterhead 18. Cutterhead rotation and machine advance causes the disc cutter elements 26 to cut concentric kerfs in the tunnel face and to dislodge the material between the kerfs. The dislodged material is picked up by the scoops 28 and delivered into an overhead chute which deposits such material onto the conveyor housed within the beam 16. As the frame 12 moves forwardly the guide rail 62 moves forwardly through the guide bearings 58, 60 on the carrier 32. When the propulsion rams 72, 74 reach the ends of their stroke, the cylinders 36, 38 are retracted to withdraw the gripper pads 50, 52 from engagement with the tunnel wall. Then, the propulsion rams 72, 74 are retracted to in that manner pull the gripper assembly 70 forwardly along the rail 62. When the gripper assembly is at a forward position on the rail 62, the cylinders 36, 38 are again extended and the above described procedure is repeated.
In preferred form, the support ring 10 is of sectional construction, and is provided with means for adjusting its diameter, as will hereinafter be explained in detail. The illustrated embodiment comprises a pair of side sections 74, 76 which are hinge connected where they meet at the bottom of the tunnel. The cutterhead support 14 rests on a pedestal 72. A large diameter pivot pin 78 may be used for both pivotally connecting the lower ends of ring sections 74, 76 together, and for pivotally mounting a lower portion of pedestal 72 onto the ring 10. Pin 78 connects the cutterhead support 14, and hence the entire frame 12, to the support ring 10 at a location close to the tunnel wall. Pin 78 provides for pivotal movement of frame 12 about the axis of pin 78. Such axis extends generally parallel to the center line of the tunnel (FIGS. 2 and 3).
The illustrated embodiment of the ring 10 also comprises a third section 80 which is the upper section of the ring. It is connected to the side sections 74, 76 by means of extendible-retractable links, such as double-acting hydraulic cylinders 82, 84. The ends of the hydraulic cylinders 82, 84 are pivotally attached to the ring sections 74, 76, 80. Extension of the cylinders 82, 84 expands the ring 10. Retraction of the hydraulic cylinders 82, 84 contracts the ring 10.
A steering cylinder 86 extends laterally of the tunnel and is connected at one of its ends to a bracket 88 secured to an upper portion of the cutterhead support 14 and at its opposite end to a bracket 90 secured to the upper section 80 of support ring 10. The ends of the cylinder 86 are connected to the brackets 88, 90 by means of pivot pins.
The cutterhead 18 cuts a circle which is generally equal to the expanded diameter of the ring 10. The center of rotation of the cutterhead 18 generally coincides with the center axis of support ring 10 when the boring machine is being used for boring a tunnel which is horizontally straight.
When it is desired to turn the machine horizontally, the steering cylinder 86 is either extended or retracted (depending on the desired direction of turn) for the purpose of tilting the cutterhead 18 sideways relative to the support ring 10 (FIG. 3). Cylinder 86 also holds the frame 12 in position relative to support ring 10. Thus, it is a means of adjustably affixing the frame 12 in position relative to support ring 10.
Preferably, the cutterhead is progressively offset sideways during advancement of the machine. This is so that the change in direction of the tunnel will be gradual and will closely follow along a smooth curve. FIG. 3 includes a broken line showing of a full offset position of cutterhead 18. When the support ring 10 enters the offset region it is influenced sideways by the change in direction of the bore.
Translation of the support ring 10 also causes the frame 12 and the cutterhead 18 to translate. The frame 12 must be moved forward in such a manner that the rear portion of beam 16, (or some other structure, e.g., an operator's station, which follows the beam 16 and moves with it) will not contact the tunnel wall. By way of example, in FIGS. 5 and 7 - 9 the side locations on the tunnel wall at the upper level of the beam 16 are labeled a, b. When the machine is being moved through a curve that is gradual enough so that the general plane of ring 10 can be substantially maintained on a radius line r, and the beam 16 substantially on a cord c, without the rear portion of beam 16 making contact with either of the tunnel side locations a, b, the machine will be turned in this fashion. Without releasing the grip on the tunnel wall the cylinder (36 or 38) which is on the inside of the curve is shortened and the opposite cylinder is lengthened an equal amount (FIG. 8). If the machine must be turned along a curve which is sharp enough that rear end contact of the beam 16 (or other trailing structure) with a side location b, c on the tunnel would prevent holding the ring 10 on a radius line and the beam 16 on a cord, the gripper cylinder (36 or 38) which is on the inside of the curve is shortened and the opposite cylinder is lengthened, so that the ring 10 and the beam 16 will occupy positions substantially as shown by FIG. 9. In FIG. 9 the cutterhead 18 is offset (by tilting) to the inside of the curve relative to the support ring 10. The side boundaries of the cutterhead 18, the ring 10 and the gripper shoes 50, 52 approximately lie on curves which correspond to the desired side boundaries of the tunnel.
Beam 16 must be able to "yaw" relative to the anchored gripper assembly as the frame 12 is translated. This movement is made possible by the pivot pin 56.
Operation of the steering cylinder 86 to tilt the cutterhead 18 sideways occurs at a time when the gripper assembly is gripping the tunnel wall. Thus, the beam 16 must "roll" relative to the anchored gripper assembly 30. Such movement is accommodated by adjustment of the torque cylinders 64, 66. The cylinder 64, 66 on the inside of the curve is shortened and the other torque cylinder is lengthened.
When the gripper shoes 50, 52 are retracted so that the gripper assembly 30 may be pulled forwardly into a new position the centering springs 68 serves to automatically return the gripper cylinders 36, 38 to centered positions with respect to the carrier 32.
As can be readily appreciated, the horizontal turning of the boring machine is achieved without any loss of roof support at the front of the machine and without a loss of grip by the gripper assembly. Ring 10 may be a portion of a shield structure which is supported on ring 10 and extends rearly from ring 10.
It is believed that the invention will have been clearly understood from the foregoing detailed description of our now-preferred illustrated embodiment. Changes in the details of construction may be resorted to without departing from the spirit of the invention and it is accordingly our intention that no limitations be implied and that the hereto annexed claims be given the broadest interpretation to which the employed language fairly admits.
1. Field of the Invention
This invention relates to earth boring machines, and in particular to machine and method aspects of driving a large head boring machine along a curve.
2. Description of the Prior Art
Examples of known earth boring machines which are advanced by thrust rams which react rearwardly against a gripper assembly are shown by U.S. Pat. No. 3,061,287, granted Oct. 30, 1972, to James S. Robbins; by U.S. Pat. No. 3,203,737, granted Aug. 31, 1965 to Richard J. Robbins, Douglas F. Winberg and John Galgoczy; by U.S. Pat. No. 3,295,892, granted Jan. 3, 1967, to Douglas F. Winberg and John Galgoczy; by U.s. Pat. No. 3,383,133, granted May 14, 1968 to Victor J. Scaravilli and Charles J. Delisio and by U.S. Pat. No. 3,598,445, granted Aug. 10, 1971 to Douglas F. Winberg.
It is known to horizontally turn a boring machine of the above described type by rolling or tilting its frame sideways about its forward lower point of support floor, so as to horizontally offset the course of the cutterhead. The mechanism used for tilting the frame comprised a pair of substantially quarter-circular shoes which are located on opposite sides of the machine. The shoes were pivotally connected at their lower ends to a lower central portion of the cutterhead support. Such shoes projected upwardly from their pivotal connections and extended along the curved lower portions of the tunnel. A double-acting hydraulic cylinder was interconnected between the upper end of each shoe and an adjacent part of the cutterhead support. The machine was tilted by a shortening of the cylinder on the side of the machine towards which the machine is to be turned and a corresponding lengthening of the opposite side cylinder. The machine included an overhead shield basically like the one disclosed by the aforementioned U.s. Pat. No. 3,295,892. It was necessary to retract such shield from the tunnel roof before the machine could be tilted sideways. As a result the roof support was lost during turning.
SUMMARY OF THE INVENTION
The tunnel boring machine of this invention includes means for tilting the cutterhead sideways relative to a forward support ring in the tunnel, for the purpose of changing the course of the tunneling machine without a loss of roof support.
In preferred form, the boring machine of this invention comprises a main frame having a forwardly positioned cutterhead support and an elongated beam which extends rearwardly in the tunnel from the cutterhead support. A gripper assembly is spaced rearwardly of the cutterhead support. Thrust rams for shoving the boring machine forwardly relative to the gripper assembly are interconnected between the gripper assembly and the frame. The frame is supported at its forward end by an expandable support ring. The frame is pivotally connected to the support ring, preferably at the base of the ring, and an adjustable link is provided between the cutterhead support and the support ring, for tilting the cutterhead support, and hence the cutterhead carried thereby, sideways relative to the support ring, for the purpose of changing the course of the boring machine.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an isometric view taken from up above, looking towards the front and one side of the basic components of an embodiment of the tunneling machine of this invention, with some parts cut away for clarity of illustration of other parts;
FIG. 2 is the side elevational view of the tunneling machine, with some components shown in section;
FIG. 3 is a cross-sectional view through the tunneling machine, taken substantially along line 3--3 of FIG. 2;
FIG. 4 is a cross-sectional view taken through the tunneling machine, substantially along line 4--4 of FIG. 2;
FIG. 5 is a cross-sectional view taken through the tunneling machine, substantially along line 5--5 of FIG. 2;
FIG. 6 is a sectional view through the gripper assembly, taken substantially along line 6--6 of FIG. 4;
FIG. 7 is a top plan view showing the tunneling machine at the end of a straight section of tunnel and about to enter a curve;
FIG. 8 is a view like FIG. 7, but showing the tunneling machine moved into the curve; and
FIG. 9 is a view like FIGS. 7 and 8, but showing the tunneling machine moved an additional amount into the curve.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the several figures of the drawing, the illustrated embodiment comprises a support ring 10 which supports the forward portion of a frame 12. Frame 12 comprises a cutterhead support 14 and an elongated beam 16 which trails rearwardly from cutterhead support 14. A rotary cutterhead 18 is mounted for rotation on the cutterhead support 14. Small drive gears 22 driven by motors 20 mesh with a large diameter gear 24 on the cutterhead 18. Cutter elements 26 on cutterhead 18 dislodge material from the tunnel face and scoops 28 pick up the material and start it along a rearward course. The material is moved through the cutterhead 18 and onto a conveyor which is housed in the main beam 16, for example, as shown by U.S. Pat. No. 3,640,077, granted Feb. 8, 1972, to Frank George Watson and David Burnett Sugden.
The mechanism which advances the boring machine forwardly in the tunnel includes a gripper assembly which is basically like the gripper assembly disclosed by the aforementioned U.S. Pat. No. 3,203,737.
The gripper assembly 30 may comprise a gripper carrier 32 having a transverse passageway 34 formed therein in which two collinear gripper cylinders 36, 38 are housed. The cylinders 36, 38 comprise piston chambers which are rigidly connected together at their closed ends by upper and lower beam members 40, 42. A piston, one of which is designated 44, is located within each cylinder 36, 38. Piston rods 46, 48 extend outwardly from the pistons (44) and at their outer ends are connected to tunnel wall engaging gripper pads 50, 52.
Referring to FIG. 6, a trunion member 54 extends between the two sides of support 32 and is mounted at its ends for rotation about an axis X which is generally directed axially of the tunnel. A pin 56 extends perpendicularly through the trunion member 54. Pin 56 extends between, and at its ends is anchored to, the two beam members 40, 42, and is rotatable relative to member 54. Owing to this arrangement the trunion member 54 and the carrier 32 are rotatable as a unit about the axis of pin 56, i.e. axis Z (FIG. 4), within the limits of the space 34.
Gripper carrier 32 includes a pair of opposed slide bearings 58, 60 which receive and guide edge portions of a rail 62 which is part of the beam 16. A pair of double-acting hydraulic cylinders 64, 66 are interconnected between upper portions of the carrier 32 and the bodies of the cylinders 36, 38 (FIG. 4). Pivotal connections are provided at each end of the cylinders 64, 66. The cylinders 64, 66 constitute adjustable torque transfer links between the frame 12 and the gripper assembly 30, as will hereinafter be explained in greater detail.
Referring to FIG. 6, the gripper carrier 32 includes four corner placed springs 68 which function to automatically center the cylinders 36, 38 with respect to the carrier 32. The compression springs 68 react against pads 70 which make sliding contact with the side wall of the cylinder housings.
In the conventional manner, a pair of double-acting hydraulic thrust rams or cylinders 72, 74 are interconnected between the gripper pads 50, 52 of the gripper assembly 30 and forward portions of the frame 12, in the vicinity of the cutterhead support 14.
FIG. 1 shows the boring machine at the start of an advance. The gripper cylinders 36, 38 are extended, forcing the gripper pads 50, 52 outwardly into gripping contact with opposite side wall portions of the tunnel. Hydraulic fluid is delivered into the thrust rams 72, 74 to cause their extension. As they extend they react rearwardly against the gripper assembly 30 and shove the frame 12, and the cutterhead 18 carried thereby, axially forwardly against the tunnel face. At the same time the motors 20 are operated to rotate the cutterhead 18. Cutterhead rotation and machine advance causes the disc cutter elements 26 to cut concentric kerfs in the tunnel face and to dislodge the material between the kerfs. The dislodged material is picked up by the scoops 28 and delivered into an overhead chute which deposits such material onto the conveyor housed within the beam 16. As the frame 12 moves forwardly the guide rail 62 moves forwardly through the guide bearings 58, 60 on the carrier 32. When the propulsion rams 72, 74 reach the ends of their stroke, the cylinders 36, 38 are retracted to withdraw the gripper pads 50, 52 from engagement with the tunnel wall. Then, the propulsion rams 72, 74 are retracted to in that manner pull the gripper assembly 70 forwardly along the rail 62. When the gripper assembly is at a forward position on the rail 62, the cylinders 36, 38 are again extended and the above described procedure is repeated.
In preferred form, the support ring 10 is of sectional construction, and is provided with means for adjusting its diameter, as will hereinafter be explained in detail. The illustrated embodiment comprises a pair of side sections 74, 76 which are hinge connected where they meet at the bottom of the tunnel. The cutterhead support 14 rests on a pedestal 72. A large diameter pivot pin 78 may be used for both pivotally connecting the lower ends of ring sections 74, 76 together, and for pivotally mounting a lower portion of pedestal 72 onto the ring 10. Pin 78 connects the cutterhead support 14, and hence the entire frame 12, to the support ring 10 at a location close to the tunnel wall. Pin 78 provides for pivotal movement of frame 12 about the axis of pin 78. Such axis extends generally parallel to the center line of the tunnel (FIGS. 2 and 3).
The illustrated embodiment of the ring 10 also comprises a third section 80 which is the upper section of the ring. It is connected to the side sections 74, 76 by means of extendible-retractable links, such as double-acting hydraulic cylinders 82, 84. The ends of the hydraulic cylinders 82, 84 are pivotally attached to the ring sections 74, 76, 80. Extension of the cylinders 82, 84 expands the ring 10. Retraction of the hydraulic cylinders 82, 84 contracts the ring 10.
A steering cylinder 86 extends laterally of the tunnel and is connected at one of its ends to a bracket 88 secured to an upper portion of the cutterhead support 14 and at its opposite end to a bracket 90 secured to the upper section 80 of support ring 10. The ends of the cylinder 86 are connected to the brackets 88, 90 by means of pivot pins.
The cutterhead 18 cuts a circle which is generally equal to the expanded diameter of the ring 10. The center of rotation of the cutterhead 18 generally coincides with the center axis of support ring 10 when the boring machine is being used for boring a tunnel which is horizontally straight.
When it is desired to turn the machine horizontally, the steering cylinder 86 is either extended or retracted (depending on the desired direction of turn) for the purpose of tilting the cutterhead 18 sideways relative to the support ring 10 (FIG. 3). Cylinder 86 also holds the frame 12 in position relative to support ring 10. Thus, it is a means of adjustably affixing the frame 12 in position relative to support ring 10.
Preferably, the cutterhead is progressively offset sideways during advancement of the machine. This is so that the change in direction of the tunnel will be gradual and will closely follow along a smooth curve. FIG. 3 includes a broken line showing of a full offset position of cutterhead 18. When the support ring 10 enters the offset region it is influenced sideways by the change in direction of the bore.
Translation of the support ring 10 also causes the frame 12 and the cutterhead 18 to translate. The frame 12 must be moved forward in such a manner that the rear portion of beam 16, (or some other structure, e.g., an operator's station, which follows the beam 16 and moves with it) will not contact the tunnel wall. By way of example, in FIGS. 5 and 7 - 9 the side locations on the tunnel wall at the upper level of the beam 16 are labeled a, b. When the machine is being moved through a curve that is gradual enough so that the general plane of ring 10 can be substantially maintained on a radius line r, and the beam 16 substantially on a cord c, without the rear portion of beam 16 making contact with either of the tunnel side locations a, b, the machine will be turned in this fashion. Without releasing the grip on the tunnel wall the cylinder (36 or 38) which is on the inside of the curve is shortened and the opposite cylinder is lengthened an equal amount (FIG. 8). If the machine must be turned along a curve which is sharp enough that rear end contact of the beam 16 (or other trailing structure) with a side location b, c on the tunnel would prevent holding the ring 10 on a radius line and the beam 16 on a cord, the gripper cylinder (36 or 38) which is on the inside of the curve is shortened and the opposite cylinder is lengthened, so that the ring 10 and the beam 16 will occupy positions substantially as shown by FIG. 9. In FIG. 9 the cutterhead 18 is offset (by tilting) to the inside of the curve relative to the support ring 10. The side boundaries of the cutterhead 18, the ring 10 and the gripper shoes 50, 52 approximately lie on curves which correspond to the desired side boundaries of the tunnel.
Beam 16 must be able to "yaw" relative to the anchored gripper assembly as the frame 12 is translated. This movement is made possible by the pivot pin 56.
Operation of the steering cylinder 86 to tilt the cutterhead 18 sideways occurs at a time when the gripper assembly is gripping the tunnel wall. Thus, the beam 16 must "roll" relative to the anchored gripper assembly 30. Such movement is accommodated by adjustment of the torque cylinders 64, 66. The cylinder 64, 66 on the inside of the curve is shortened and the other torque cylinder is lengthened.
When the gripper shoes 50, 52 are retracted so that the gripper assembly 30 may be pulled forwardly into a new position the centering springs 68 serves to automatically return the gripper cylinders 36, 38 to centered positions with respect to the carrier 32.
As can be readily appreciated, the horizontal turning of the boring machine is achieved without any loss of roof support at the front of the machine and without a loss of grip by the gripper assembly. Ring 10 may be a portion of a shield structure which is supported on ring 10 and extends rearly from ring 10.
It is believed that the invention will have been clearly understood from the foregoing detailed description of our now-preferred illustrated embodiment. Changes in the details of construction may be resorted to without departing from the spirit of the invention and it is accordingly our intention that no limitations be implied and that the hereto annexed claims be given the broadest interpretation to which the employed language fairly admits.