Title:
Tunnelling machine on skids with extensible wheels
United States Patent 3922016
Abstract:
Tunnelling apparatus which during use is installed within tunnel lining sections and which employs a boom or jib with cutting means for detaching material from a working face to effect advancement of the tunnel. The jib is supported on a carriage which is mounted for sliding on a main frame. One or more conveyors for which the main frame serves additionally as a trough part serve to remove the detached material. The frame has skids at its sides which normally rest on the floor region of the lining sections but the frame is rendered displaceable in relation to the lining sections with the aid of wheel assemblies carried by the frame. These wheel assemblies enable the frame to move longitudinally or transversally and have mechanisms whereby the assemblies can be either operable or non-operable as desired.
US Patent References:
/1140673.html
Giggey - May 1915 - 1140673
/1219071.html
Bodnar - March 1917 - 1219071
Tunneling and excavation through rock by core forming and removal
Enz - June 1967 - 3325217
MINING MACHINE WITH SELECTIVELY RETAINABLE LOADING APRON
Meissner et al. - April 1969 - 3437382
TUNNELLING MEANS AND METHOD
Cowley - September 1971 - 3603100
/1140673.html
Giggey - May 1915 - 1140673
/1219071.html
Bodnar - March 1917 - 1219071
Tunneling and excavation through rock by core forming and removal
Enz - June 1967 - 3325217
MINING MACHINE WITH SELECTIVELY RETAINABLE LOADING APRON
Meissner et al. - April 1969 - 3437382
TUNNELLING MEANS AND METHOD
Cowley - September 1971 - 3603100
Inventors:
Tyslauk, Willy (Altlunen, DT)
Bargel, Gunther (Werne, DT)
Bargel, Gunther (Werne, DT)
Application Number:
05/469726
Publication Date:
11/25/1975
Filing Date:
05/14/1974
View Patent Images:
Export Citation:
Assignee:
Gewerkschaft, Eisenhutte Westfalia (Westfalia, DT)
Primary Class:
Other Classes:
299/75, 299/56, 280/43.140, 299/33
International Classes:
E21D9/08; E21D9/10; E21D9/12; E21D9/08
Field of Search:
299/31,33,56,75 173/23 280/43.14,43.24
Primary Examiner:
Purser, Ernest R.
Attorney, Agent or Firm:
Sughrue, Rothwell, Mion, Zinn & Macpeak
Claims:
We claim
1. A tunnelling apparatus for installation in one or more of a series of tunnel lining sections, said apparatus comprising:
2. An apparatus according to claim 1, wherein said anchoring means comprises a hydraulic jack carrying a shoe engageable with the inner surface of one of the lining sections.
3. An apparatus according to claim 1, wherein each wheel assembly is provided with an adjustment mechanism for effecting said selective operation of the assembly.
4. an apparatus according to claim 3, wherein each adjustment mechanism is a hydraulic piston and cylinder unit.
5. An apparatus according to claim 1, wherein the wheel assemblies and skids are disposed at the sides of the frame relative to the direction of tunnel advancement, with the wheel assemblies disposed between adjacent skids at each side of the frame.
6. An apparatus according to claim 1, wherein said first wheel assemblies each comprise a wheel rotatably mounted on an arm which is pivotable relative to the frame about an axis extending generally parallel to the longitudinal axis of the frame and wherein the adjustment mechanism for each of said some wheel assemblies is operable to effect pivotal movement of the arm.
7. An apparatus according to claim 6, wherein the adjustment mechanism for each of said first wheel assemblies is a threaded member engaged in a threaded bore in a bracket attached to the frame, the threaded member bearing on an abutment face of the arm so as to exert leverage on the arm when rotated.
8. An apparatus according to claim 1, wherein said second wheel assemblies each comprise a wheel rotatably mounted on a shaft which is located for displacement within guideways and wherein the adjustment mechanism for each of said remainder of the wheel assemblies is operable to move the shaft in a vertical plane within the guideways.
9. An apparatus according to claim 8, wherein the adjustment mechanism for each of said second wheel assemblies is at least one threaded member engaged in a threaded bore in a bracket attached to the frame, the threaded member being secured to or bearing on the shaft so as to move the latter when rotated.
10. An apparatus according to claim 1, wherein the sides of the frame are constructed as guide beams, a carriage is slidably supported on upper surfaces of these guide means and carries the detaching means and a ram is provided to effect relative movement between the carriage and the frame, the skids being secured to the guide beams with said some wheel assemblies being provided generally at the underside of the guide beams and the remainder of the wheel assemblies being provided at the exterior sides of the guide beams.
1. A tunnelling apparatus for installation in one or more of a series of tunnel lining sections, said apparatus comprising:
2. An apparatus according to claim 1, wherein said anchoring means comprises a hydraulic jack carrying a shoe engageable with the inner surface of one of the lining sections.
3. An apparatus according to claim 1, wherein each wheel assembly is provided with an adjustment mechanism for effecting said selective operation of the assembly.
4. an apparatus according to claim 3, wherein each adjustment mechanism is a hydraulic piston and cylinder unit.
5. An apparatus according to claim 1, wherein the wheel assemblies and skids are disposed at the sides of the frame relative to the direction of tunnel advancement, with the wheel assemblies disposed between adjacent skids at each side of the frame.
6. An apparatus according to claim 1, wherein said first wheel assemblies each comprise a wheel rotatably mounted on an arm which is pivotable relative to the frame about an axis extending generally parallel to the longitudinal axis of the frame and wherein the adjustment mechanism for each of said some wheel assemblies is operable to effect pivotal movement of the arm.
7. An apparatus according to claim 6, wherein the adjustment mechanism for each of said first wheel assemblies is a threaded member engaged in a threaded bore in a bracket attached to the frame, the threaded member bearing on an abutment face of the arm so as to exert leverage on the arm when rotated.
8. An apparatus according to claim 1, wherein said second wheel assemblies each comprise a wheel rotatably mounted on a shaft which is located for displacement within guideways and wherein the adjustment mechanism for each of said remainder of the wheel assemblies is operable to move the shaft in a vertical plane within the guideways.
9. An apparatus according to claim 8, wherein the adjustment mechanism for each of said second wheel assemblies is at least one threaded member engaged in a threaded bore in a bracket attached to the frame, the threaded member being secured to or bearing on the shaft so as to move the latter when rotated.
10. An apparatus according to claim 1, wherein the sides of the frame are constructed as guide beams, a carriage is slidably supported on upper surfaces of these guide means and carries the detaching means and a ram is provided to effect relative movement between the carriage and the frame, the skids being secured to the guide beams with said some wheel assemblies being provided generally at the underside of the guide beams and the remainder of the wheel assemblies being provided at the exterior sides of the guide beams.
Description:
BACKGROUND OF THE INVENTION
The present invention relates to apparatus for use in tunnelling.
In driving a tunnel, it is known to provide a series of tunnel lining components or sections which are usually of cylindrical form and arranged end-to-end to support the tunnell wall. A pressing station then serves to force these sections in the direction of advancement of the tunnel. In order to detach and remove the material from the working face apparatuses of various forms can be arranged within the foremost lining section or sections. During certain stages of the tunnel driving operation it often becomes necessary to fix the apparatus in relation to the lining section or to adjust the position of the apparatus in relation to the lining section. This latter function is especially necessary where the forces developed by the machine or the forces acting on the exterior of the lining sections cause the lining sections to move themselves so that the apparatus becomes displaced. Hitherto, this adjustment has in particular created many problems in view of the fact that in general the apparatus is usually long and heavy and the working space is exceedingly cramped.
Having regard to the foregoing a general object of the invention is to provide an improved form of tunnelling apparatus.
SUMMARY OF THE INVENTION
According to the invention there is provided a tunnelling apparatus for installation in one or more of a series of tunnel lining sections; said apparatus comprising a main frame which supports means for detaching material from a working face to effect advancement of the tunnel and selectively operable wheel assemblies permitting the frame to become displaceable in relation to the lining sections.
Preferably the frame is also provided with skids. These skids serve to rest on the floor region of the lining section or sections to support the frame when the wheel assemblies are non-operative. An anchoring means can be provided to clamp the frame to the lining sections when the latter is supported by the skids. When the anchoring means is released, however, the wheel assemblies can be operated to lift the skids clear of the floor region of the lining sections and the frame can then be easily moved and adjusted relative to the lining sections. In accordance with a preferred feature of the invention some of the wheel assemblies are operable to permit the frame to be displaced generally longitudinally and the remainder of the wheel assemblies are operable to permit the frame to be displaced generally transversally.
Each wheel assembly may have its own adjustment mechanism which can being the assembly into an operative state by moving the wheel thereof against the inner surface of the lining or sections. In a preferred construction the wheel assemblies for longitudinal movement each comprise a wheel rotatably mounted on an arm which is itself pivotable in relation to the frame about an axis parallel to the longitudinal axis of the tunnel. The adjusting mechanism for the assembly then serves to pivot the arm to effect operation of the wheel assembly. In contrast, the wheel assemblies for transverse movement each comprise a wheel rotatably mounted on a shaft which extends parallel to the longitudinal axis of the tunnel and which is bodily displaced within guideways by the adjusting mechanism therfor.
The wheel assemblies and skids can be conveniently arranged on each side of the frame and preferably on guide beams thereof which slidably support a carriage carrying the detaching means. The detaching means may take the form of a boom or jib which swings in relation to the carriage and having a cutting drum at its free end.
The wheel assemblies at each side of the frame may be positioned between the skids thereat with the wheel assemblies for longitudinal movement disposed at the underside of the guide beam and the wheel assemblies for transverse movement disposed above the other wheel assemblies and at the exterior side of the guide beam. Preferably there are at least two wheel assemblies for longitudinal movement and at least two wheel assemblies for transverse movement at each side of the frame.
It is advantageous for the frame to be so constructed as to form a trough part for a conveyor serving to transport detached material away from the face.
The invention may be understood more readily and various other features of the invention may become more apparent from consideration of the following description.
BRIEF DESCRIPTION OF DRAWINGS
An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein:
FIG. 1 is a diagrammatic side view of an apparatus made in accordance with the invention;
FIG. 2 is a sectional view of part of the apparatus, the view being taken along the line II -- II of FIG. 1;
FIG. 3 is a somewhat enlarged detail view taken along the line III -- III of FIG. 1; and
FIG. 4 is a somewhat enlarged detail view taken along the line IV -- IV of FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENT
As shown in FIG. 1 of the drawings a tunnelling apparatus is installed as is known, within a series of tubular lining sections 10 forming a lining for the tunnel. In known manner these lining sections 10 are arranged end-to-end and forced in the direction of the tunnel advance by means of a pressing station (not shown). The foremost lining section 10 has a cutting edge at its front end designed to penetrate into the working face 11. The apparatus disposed within these lining sections 10 has a jib 13 supported by a carriage 21 which in turn is slidably supported on a main frame 22. The jib 13, which is provided with cutting means such as a cutting drum 14, serves to detach material from the face 11. The jib 13 can be swung horizontally or vertically and to this end the jib 13 is pivoted by means of a horizontal pivot pin 19 to a support table which itself can pivot about a vertical axis in relation to the carriage 21. Hydraulic piston and cylinder units serve to pivot the jib 13 about the pin 19 and to pivot the support table only. One of these units denoted 18 is represented in FIG. 1.
A hydraulic ram 20 is connected between the main frame 22 and the carriage 21 and this ram 20 serves to displace the carriage 21 back and forth along the frame 22 in a direction parallel to the longitudinal axis of the tunnel. Material which is detached from the face 11 by the cutting means 14 of the jib 13 is taken up by a scraper-chain type conveyor incorporated in the jib 13 and the material is discharged from this conveyor at the zone 15 and passes via a chute 16 onto a further rear conveyor 17. This conveyor 16 then discharges the material from an elevated zone 17'. The rear end of the conveyor constituting the elevated zone 17' is supported by a unit which is preferably mobile and accommodates drive means for the conveyor 13 and for the other parts of the apparatus. The conveyor 17 is preferably constructed so that it can be extended, by introducing additional troughs for example, to cope with the advancement of the tunnel.
The main frame 22 actually serves as a trough part 23 of the conveyor 17 and as shown in FIG. 2 the frame 22 has side walls and a floor defining the trough part 23 over which a scraper-chain assembly moves in known manner. At the outside of each of these sidewalls there is a guide beam 24, which is conveniently a hollow structure. The upper surfaces of these guide beams slidably support the carriage 21. The frame 22 is also provided with support means in the form of skids and wheels as described hereinafter.
Anchoring means is provided for clamping the frame 22 in relation to the lining sections 10. This anchoring means has an arcuate-shaped shoe 26 with a radius of curvature matching that of the lining sections 10. The shoe 26 can engage on an upper region of one of the sections 10 and is carried by the extendable column 27 of a hydraulic jack 25 which can be operated to press the shoe 26 against the associated lining section 10 when clamping is desired. When the shoe 26 is lowered however the frame 22 can be displaced relative to the lining sections 10. Instead of a hydraulic jack 25 a screw-threaded spindle could be employed to support the shoe 26.
The main frame 22 is provided at each side with a set of skids which extend longitudinally of the apparatus and can rest on the floor region of the lining section or sections 10. Usually the skids engage on the floor region of the foremost section 10. Each set of skids is in the form of three hollow tubular or solid rod-like elements 28', 28, 28" arranged on each side of the frame 22 and affixed to the beams 24 by means of brackets 29 as shown in FIG. 2. The central longer element 28 at each side of the frame 22 is spaced apart from the shorter end elements 28', 28" and the element 28. The wheel assemblies 30 serve to render the frame 22 mobile in a direction longitudinally of the frame 22 and the lining sections 10 whereas the wheel assemblies 35 serve to render the frame 22 mobile in a direction generally transversally of the frame 22 circumferentially of the lining sections 10.
Dealing first with the assemblies 30, and referring to FIG. 4 which depicts one of these assemblies 30, the wheel of the assembly 30 is rotatably mounted on an arm 31 which is pivotably attached by means of a pin 32 to a bracket secured to the frame 22. The axis of the pin 32 extends parallel to the longitudinal axis of the frame 22 and the overall apparatus. A further support bracket 34 is secured to the frame 22, more specifically to the beam 24 thereof, and a threaded member 33 is provided in a screw-threaded vertical bore in the bracket 34. The wheel itself is protected by the beam 24. The threaded member 33 is arranged to engage an abutment face at the end of the arm 31 remote from the pin 32. The wheel of the assembly engages on the inside of one of the lining sections 10 and by adjusting the member 33 the arm 31 can be swung around the pivot pin 32 so that the associated skids 28, 28', 28" are lifted off the floor region of the lining sections 10. In this way the assemblies 30 can be adjusted so that the frame 22 becomes wholly supported by the wheels. The wheels are disposed close to the pivot pins 32 so that the overall length of the arm 31 between each wheel and the associated member 33 provides adequate leverage. The wheel assemblies 30 constructed in this manner thus allow the frame 33 and hence the entire apparatus to be raised and supported on the wheels of the assemblies 30 for movement along the lining sections or lowered and supported on the skids 28, 28', 28".
The wheel assemblies 35 for circumferential movement are provided adjacent to and generally above the assemblies 30. Referring now to FIG. 3, which depicts one of the assemblies 35, a bracket 36 is affixed to the beam 24. The bracket 36 has guide strips 37 which form guideways which locate the shaft 38 of the wheels therebetween. Threaded members 39 engage in threaded bores in the bracket 36 and abut, or are secured to, the shaft 38 of the wheel. The members 39 can be adjusted to displace the shaft 38 in a vertical plane so that the skids 28, 28', 28" can again be lifted off the floor region of the lining sections 10.
The frame 22 can thus become supported by the wheels of the assemblies 31 which engage on the inside of one of the lining sections 10 in an analogous fashion to the assemblies 30, so that the frame 22 and hence the entire apparatus can be raised and supported on the wheels of the assemblies 35 for movement circumferentially of the lining sections or lowered and supported on the skids 28, 28', 28". The provision of the assemblies 30, 35 which can be selectively operated as described enables the entire apparatus to be repositioned at will.
Instead of the threaded members 33, 34 serving for the selective adjustment of the wheels of the assemblies 30, 35 it is possible to utilize small hydraulic piston and cylinder units for this purpose.
The present invention relates to apparatus for use in tunnelling.
In driving a tunnel, it is known to provide a series of tunnel lining components or sections which are usually of cylindrical form and arranged end-to-end to support the tunnell wall. A pressing station then serves to force these sections in the direction of advancement of the tunnel. In order to detach and remove the material from the working face apparatuses of various forms can be arranged within the foremost lining section or sections. During certain stages of the tunnel driving operation it often becomes necessary to fix the apparatus in relation to the lining section or to adjust the position of the apparatus in relation to the lining section. This latter function is especially necessary where the forces developed by the machine or the forces acting on the exterior of the lining sections cause the lining sections to move themselves so that the apparatus becomes displaced. Hitherto, this adjustment has in particular created many problems in view of the fact that in general the apparatus is usually long and heavy and the working space is exceedingly cramped.
Having regard to the foregoing a general object of the invention is to provide an improved form of tunnelling apparatus.
SUMMARY OF THE INVENTION
According to the invention there is provided a tunnelling apparatus for installation in one or more of a series of tunnel lining sections; said apparatus comprising a main frame which supports means for detaching material from a working face to effect advancement of the tunnel and selectively operable wheel assemblies permitting the frame to become displaceable in relation to the lining sections.
Preferably the frame is also provided with skids. These skids serve to rest on the floor region of the lining section or sections to support the frame when the wheel assemblies are non-operative. An anchoring means can be provided to clamp the frame to the lining sections when the latter is supported by the skids. When the anchoring means is released, however, the wheel assemblies can be operated to lift the skids clear of the floor region of the lining sections and the frame can then be easily moved and adjusted relative to the lining sections. In accordance with a preferred feature of the invention some of the wheel assemblies are operable to permit the frame to be displaced generally longitudinally and the remainder of the wheel assemblies are operable to permit the frame to be displaced generally transversally.
Each wheel assembly may have its own adjustment mechanism which can being the assembly into an operative state by moving the wheel thereof against the inner surface of the lining or sections. In a preferred construction the wheel assemblies for longitudinal movement each comprise a wheel rotatably mounted on an arm which is itself pivotable in relation to the frame about an axis parallel to the longitudinal axis of the tunnel. The adjusting mechanism for the assembly then serves to pivot the arm to effect operation of the wheel assembly. In contrast, the wheel assemblies for transverse movement each comprise a wheel rotatably mounted on a shaft which extends parallel to the longitudinal axis of the tunnel and which is bodily displaced within guideways by the adjusting mechanism therfor.
The wheel assemblies and skids can be conveniently arranged on each side of the frame and preferably on guide beams thereof which slidably support a carriage carrying the detaching means. The detaching means may take the form of a boom or jib which swings in relation to the carriage and having a cutting drum at its free end.
The wheel assemblies at each side of the frame may be positioned between the skids thereat with the wheel assemblies for longitudinal movement disposed at the underside of the guide beam and the wheel assemblies for transverse movement disposed above the other wheel assemblies and at the exterior side of the guide beam. Preferably there are at least two wheel assemblies for longitudinal movement and at least two wheel assemblies for transverse movement at each side of the frame.
It is advantageous for the frame to be so constructed as to form a trough part for a conveyor serving to transport detached material away from the face.
The invention may be understood more readily and various other features of the invention may become more apparent from consideration of the following description.
BRIEF DESCRIPTION OF DRAWINGS
An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein:
FIG. 1 is a diagrammatic side view of an apparatus made in accordance with the invention;
FIG. 2 is a sectional view of part of the apparatus, the view being taken along the line II -- II of FIG. 1;
FIG. 3 is a somewhat enlarged detail view taken along the line III -- III of FIG. 1; and
FIG. 4 is a somewhat enlarged detail view taken along the line IV -- IV of FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENT
As shown in FIG. 1 of the drawings a tunnelling apparatus is installed as is known, within a series of tubular lining sections 10 forming a lining for the tunnel. In known manner these lining sections 10 are arranged end-to-end and forced in the direction of the tunnel advance by means of a pressing station (not shown). The foremost lining section 10 has a cutting edge at its front end designed to penetrate into the working face 11. The apparatus disposed within these lining sections 10 has a jib 13 supported by a carriage 21 which in turn is slidably supported on a main frame 22. The jib 13, which is provided with cutting means such as a cutting drum 14, serves to detach material from the face 11. The jib 13 can be swung horizontally or vertically and to this end the jib 13 is pivoted by means of a horizontal pivot pin 19 to a support table which itself can pivot about a vertical axis in relation to the carriage 21. Hydraulic piston and cylinder units serve to pivot the jib 13 about the pin 19 and to pivot the support table only. One of these units denoted 18 is represented in FIG. 1.
A hydraulic ram 20 is connected between the main frame 22 and the carriage 21 and this ram 20 serves to displace the carriage 21 back and forth along the frame 22 in a direction parallel to the longitudinal axis of the tunnel. Material which is detached from the face 11 by the cutting means 14 of the jib 13 is taken up by a scraper-chain type conveyor incorporated in the jib 13 and the material is discharged from this conveyor at the zone 15 and passes via a chute 16 onto a further rear conveyor 17. This conveyor 16 then discharges the material from an elevated zone 17'. The rear end of the conveyor constituting the elevated zone 17' is supported by a unit which is preferably mobile and accommodates drive means for the conveyor 13 and for the other parts of the apparatus. The conveyor 17 is preferably constructed so that it can be extended, by introducing additional troughs for example, to cope with the advancement of the tunnel.
The main frame 22 actually serves as a trough part 23 of the conveyor 17 and as shown in FIG. 2 the frame 22 has side walls and a floor defining the trough part 23 over which a scraper-chain assembly moves in known manner. At the outside of each of these sidewalls there is a guide beam 24, which is conveniently a hollow structure. The upper surfaces of these guide beams slidably support the carriage 21. The frame 22 is also provided with support means in the form of skids and wheels as described hereinafter.
Anchoring means is provided for clamping the frame 22 in relation to the lining sections 10. This anchoring means has an arcuate-shaped shoe 26 with a radius of curvature matching that of the lining sections 10. The shoe 26 can engage on an upper region of one of the sections 10 and is carried by the extendable column 27 of a hydraulic jack 25 which can be operated to press the shoe 26 against the associated lining section 10 when clamping is desired. When the shoe 26 is lowered however the frame 22 can be displaced relative to the lining sections 10. Instead of a hydraulic jack 25 a screw-threaded spindle could be employed to support the shoe 26.
The main frame 22 is provided at each side with a set of skids which extend longitudinally of the apparatus and can rest on the floor region of the lining section or sections 10. Usually the skids engage on the floor region of the foremost section 10. Each set of skids is in the form of three hollow tubular or solid rod-like elements 28', 28, 28" arranged on each side of the frame 22 and affixed to the beams 24 by means of brackets 29 as shown in FIG. 2. The central longer element 28 at each side of the frame 22 is spaced apart from the shorter end elements 28', 28" and the element 28. The wheel assemblies 30 serve to render the frame 22 mobile in a direction longitudinally of the frame 22 and the lining sections 10 whereas the wheel assemblies 35 serve to render the frame 22 mobile in a direction generally transversally of the frame 22 circumferentially of the lining sections 10.
Dealing first with the assemblies 30, and referring to FIG. 4 which depicts one of these assemblies 30, the wheel of the assembly 30 is rotatably mounted on an arm 31 which is pivotably attached by means of a pin 32 to a bracket secured to the frame 22. The axis of the pin 32 extends parallel to the longitudinal axis of the frame 22 and the overall apparatus. A further support bracket 34 is secured to the frame 22, more specifically to the beam 24 thereof, and a threaded member 33 is provided in a screw-threaded vertical bore in the bracket 34. The wheel itself is protected by the beam 24. The threaded member 33 is arranged to engage an abutment face at the end of the arm 31 remote from the pin 32. The wheel of the assembly engages on the inside of one of the lining sections 10 and by adjusting the member 33 the arm 31 can be swung around the pivot pin 32 so that the associated skids 28, 28', 28" are lifted off the floor region of the lining sections 10. In this way the assemblies 30 can be adjusted so that the frame 22 becomes wholly supported by the wheels. The wheels are disposed close to the pivot pins 32 so that the overall length of the arm 31 between each wheel and the associated member 33 provides adequate leverage. The wheel assemblies 30 constructed in this manner thus allow the frame 33 and hence the entire apparatus to be raised and supported on the wheels of the assemblies 30 for movement along the lining sections or lowered and supported on the skids 28, 28', 28".
The wheel assemblies 35 for circumferential movement are provided adjacent to and generally above the assemblies 30. Referring now to FIG. 3, which depicts one of the assemblies 35, a bracket 36 is affixed to the beam 24. The bracket 36 has guide strips 37 which form guideways which locate the shaft 38 of the wheels therebetween. Threaded members 39 engage in threaded bores in the bracket 36 and abut, or are secured to, the shaft 38 of the wheel. The members 39 can be adjusted to displace the shaft 38 in a vertical plane so that the skids 28, 28', 28" can again be lifted off the floor region of the lining sections 10.
The frame 22 can thus become supported by the wheels of the assemblies 31 which engage on the inside of one of the lining sections 10 in an analogous fashion to the assemblies 30, so that the frame 22 and hence the entire apparatus can be raised and supported on the wheels of the assemblies 35 for movement circumferentially of the lining sections or lowered and supported on the skids 28, 28', 28". The provision of the assemblies 30, 35 which can be selectively operated as described enables the entire apparatus to be repositioned at will.
Instead of the threaded members 33, 34 serving for the selective adjustment of the wheels of the assemblies 30, 35 it is possible to utilize small hydraulic piston and cylinder units for this purpose.