US3312071A

US3312071A - Mine roof support cap with cantilever projection member

Info

Publication number: US3312071A
Application number: US548161A
Authority: US
Inventors: Dommann Gunther
Original assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Current assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Priority date: 1965-05-08
Filing date: 1966-05-06
Publication date: 1967-04-04
Anticipated expiration: 1984-04-04
Also published as: DE1221177B; ES326458A1; BE680651A; GB1136275A; NL6606009A

Description

April 4, 1967 G. DOMMANN 3,312,071

MINE ROOF SUPPORT CAP WITH CANTILEVER PROJECTION MEMBER Filed May 6. 1966 INVENTOR. GUN THE/Q DOMMA NN 9M wig #771: IVE vs United States Patent Ofifice Patented Apr. 4, 1967 11 Claims. for. 61-45) The present invention relates to a mine roof support cap adapted to engage supportingly a mine roof thereabove, and more particularly to such a mine roof support cap having situated longitudinally on the upper side thereof a cantilever roof cap projection member in sup porting contact therewith and movable longitudinally relative thereto.

Mining prop arrangements are known which include a pair of mining prop frames, each containing a pair of extensible pit props or mining props interconnected at their lower ends by a common skid member and at their upper ends by a common roof cap. The prop frames are operatively interconnected in side-by-side relation via a motive means, such as a piston-cylinder means, so that one prop frame, including a pair of props, interconnected at their lower ends by a skid member and at their upper ends by a roof cap, may be advanced with respect to the other prop frame. The reciprocal piston-cylinder means in turn will cause the step-by-step advancement of each frame with respect to the other, generally toward the mine face being worked as the extraction of mineral progresses, such as by the usual longwall mining methods.

However, the mining machine, usually a mining planer, is mounted on a longitudinally extending conveyor at the mine face for movement back and forth therealong in extractive engagement with the mine face, such that the mineral which is extracted thereby is conducted from the alley between the mine face and the adjacent mining conveyor, upwardly onto such conveyor for removal from the site of mining operations. Necessarily, the transverse space between the mine face and the side of the conveyor remote therefrom should be kept as small as possible, since this area is not usually able to be supported by pit props or mining props. The reason for this is that the typical mining frame arrangements used to support the mine roof must be located on the side of the conveyor remote from the mine face and can only support the mine roof above the conveyor and in the alley between the conveyor and the mine face by cantilever extensions on the roof caps of the mining frame arrangements.

Usually this is accomplished by providing articulatedly connected cantilever projection members on the longitudinal end of the appropriate transversely extending roof cap adjacent the mine face. Thus, as soon as the roof in the area of the mine face being worked has been stripped of mineral thereat to a sufiicient depth and breadth, the cantilever supports are swung upwardly and secured in their supporting position by wedges or other appropriate means placing the cantilever members in alignment with the main roof cap to which they are connected.

Disadvantageously, in the prior art constructions of mining prop arrangements including cantilever roof supports or extensions on the ends of the main roof caps adjacent the mine face, the cantilever roof support memhere could not be extended in length. Their length generally was made relatively short in order to permit suitable support of the roof as soon as possible after the same had been stripped of mineral thereat. While constructions have been proposed in which the cantilever support members were provided in such a manner that a plurality could. be used in tandem, if desired, the load which such a cantilever tandem construction could carry diminished rapidly with the number of joints between the tandem arranged members.

Therefore, despite the prior art usage of cantilever members projecting from the front ends of the roof caps of the prop frame arrangements adjacent the mine face, inadequate and inefficient support was attained.

It is an object of the present invention to overcome the foregoing drawbacks and to provide a mine roof support cap arrangement having situated longitudinally on the upper side thereof a cantilever roof cap projection member in supporting contact therewith which is movable longitudinally relative thereto in an infinite range to permit more versatile and efficient preliminary support of the mine roof above the conveyor and the alley extending between the conveyor and the mine face being worked, than was heretofore possible.

It is another object of the present invention to provide a construction of the foregoing type which permits the cantilever projection member to extend and retract in an infinite range yet which maintains consistently a high level of support of the mine roof thereat regardless of whether the cantilever projection member is fully retract ed or fully extended.

It is a further object of the present invention to provide a cantilever projection member for a mine roof support cap of the foregoing type, which is inexpensive to construct, relatively simple in make up, and durable in use.

Other and further objects of the present invention will become apparent from a study of the within specification and accompanying drawings, in which:

FIG. 1 is a schematic sectional View of the construction of a roof cap having a cantilever projection member situated thereon, in accordance with one embodiment of the present invention, and

FIG. 2 is a schematic sectional view of the roof cap and cantilever projection member, taken along the line 22 of FIG. 1, and illustrating the positional relationship between such cap and member, and showing the manner by which the roof cap is mounted on a prop head of a pit prop or mining prop in connection with which the arrangement is used.

It has been found in accordance with the present invention that a mine roof support cap adapted to engage supportingly a mine roof the'reabove may be provided effectively and advantageously with a cantilever roof cap projection member situated longitudinally on the upper side thereof in supporting contact therewith and movable longitudinally relative thereto between a retracted position overlying a greater longitudinal portion of said cap and an extended cantilever position overlying a lesser longitudinal portion of said cap in cantilever supported relation therewith, at least a portion of said member remaining in supporting contact with said cap in any position of longitudinal movement of said member with respect to said cap, whereby when said cap is in supporting engagement with the mine roof, at least a portion of said member will be supportingly interposed in clamped disposition between said cap and such roof.

Referring to the drawing, in FIG. 1 a front roof support cap 1 is provided as well as a rear roof support cap 2, the additional roof cap 2 being articulatedly interconnected with the front cap 1 by means of a horizontal articulation pin 3 interposed in the vertical slot opening 6 defined by the appropriate outer pair of projections 4 disposed at the rear end of cap 1 and the inner pair of projections 5 disposed at the front end of the rear cap 2. A depending stop element 7 is provided on the articulation pin 3 so that the downward canting of cap 1 and cap 2 with respect 3 to one another about pin 3 will be limited since the stop surface 9 at the underside of cap 1 and the stop surface 8 at the underside of cap 2 will abut the appropriate end portions of stop element '7. Because of the vertical slot opening 6, the pin 3 may be displaced vertically, whereby in turn the

caps

1 and 2 may be displaced verticallywith repect to one another as well as canted about the transverse horizontal axis of pin 3. Such vertical displacement of cap 1 and cap 2 with respect to one another is useful for accommodating unevenness in the mine roof as is true of the articulated connection arrangement of

caps

1 and 2, and is also useful in accordance with the construction of the present invention to permit the interposition of the cantilever roof support cap front projection member 14 between cap 1 and the mine roof thereabove.

Cap 1 is provided with a prop support recess 11? while cap 2 is provide-d with a prop support recess 11, whereby to accommodate a corresponding pit prop means (not shown) to form a mining prop frame. Such mining prop frames are well known and may be appreciated from US. Patents 3.l69,377, 3,174,289, 3,186,179, 3,192,722, 3,225,547, and 3,237,903.

The front roof support cap 1 is provided with a longer forward portion 12 and a shorter rearward portion 13, with respect to the prop support recess in order to permit a maximum support of the portion of the roof in the forward transverse direction beyond the particular pit prop disposed at recess 10. While this contributes a certain amount of benefit during the mining operation for supporting the mine roof in the vicinity of the mine face being worked, as additional mineral is extracted from the mine face by means of the mining machine, such as a planer, the conveyor must be advanced toward the newly exposed layer of mine face before the prop frame arrangement carrying the

roof caps

1 and 2 may be advanced transversely since the conveyor is normally disposed be tween the mining prop

arrangement containing caps

1 and 2 and the mine face. During the time before the advancement of the conveyor and in turn of the prop

arrangement containing caps

1 and 2, the mine roof ahead of the forward portion 12 of cap 1 is normally without support. This contributes an element of danger to the mine workmen because of the ever present possibility of mine roof cave in thereat. In accordance with the present invention, during this time, the cantilever projection member 14 may be extended from the retracted position shown to the position shown schematically in phantom in FIG. 1 whereby to support temporarily the otherwise perilously unsu ported mine roof thereat.

As may be seen in FIG. 2, the cantilever projection member 14 overlies the upper side of roof cap 1, the middle transverse portion of projection member 14 being in the form of a, preferably fiat, web central portion 15, with the downwardly depending lateral flanges 16 included in order to achieve convenient stabilized support of projection member 14 with respect to roof cap 1. In this regard, the corresponding lateral sides of roof cap 1 are provided with underside tracks 18 parallel to one another whereby to accommodate the inwardly directed track guides 17, also disposed in parallel relation, for retaining in a slidable manner projection member 14 on cap 1. While in the usual instance, track guides 17 will be maintained in slidable abutment with tracks 13, on the appropriate lateral side of the arrangement, the support strips 19 are constructed such that the screw-bolt connections 21) may extend therethrough to permit limited vertical displacement between the track guides 17 and the strips 19. In turn, the vertical distance between the adjacent portions of tracks 18 and track guides 17 will change and thereby the degree of canting of projection member 14 relative to cap 1. Although usually no canting or sub stantially no canting is desirable, as between projection member 14 and cap 1, in order to accommodate unevenness in the mine roof or particular mining conditions encountered, it is desirable to provide for adjustment of the distance between tracks 18 and track guides 17, whereby vertical deviation between projection member 14 and the upper side of cap 1 is possible.

As shown in PKG. 2, the recess 1% in cap 1 is provided with a prop head 19', which is in turn mounted on a pit prop (not shown) of the mining prop frame arrangement in connection with which the instant roof cap construction is utilized.

Although it will be realized that the longitudinal length of projection member 14 is a matter of choice, usually the same will have a length corresponding more or less with that of roof cap 1. Also, while any means may be used to displace, relatively, projection member 14 with respect to cap 1, whereby to effect an infinite range of relative movement between the two, within predetermined practical limits, in the usual instance a motive means will be employed for this purpose. Such motive means may be provided conveniently in the form of a piston-cylinder arrangement. As shown in FIG. 1, the cylinder 21 is connected via the rear end extension 22 with cap 1 at the downwardly projecting lug 23, situated near the recess 10'. A pivot pin 24 is used to achieve an articulated connection between cylinder 21 and cap 1. For maximum utilization of the arrangement, it is desirable to maintain the position of lug 23 as close to recess 10 as possible, since an appropriate pit prop or mining prop will be disposed in recess 10 and thereby an advantageous relationship of supporting parts will exist. Intake and exhaust

hydraulic flow conduits

25 and 26, respectively, are provided to energize cylinder 21. Thus piston rod 27 extends outwardly from the opposite end of cylinder 21, i.e. at the front end of cap 1. Piston rod 27 is connected at its free or outer end with depending lug 28 attached to the underside of projection member 14. An articulated connection in the form of a pivot pin 29 securing piston rod 27 to lug 28 is utilized. In this way, a certain amount of canting of projection menuber 14 and cap 1 with respect to one another may take place without upsetting the interconnected relationship of the piston cylinder arrangement with respect thereto. Of course, as piston rod 27 extends outwardly from cylinder 21 to displace forwardly projection member 14, for example to the position shown in phantom on the left hand side of FIG. 1, a certain pivotal movement of the interconnected parts about pivot pins 24 and 29 will take place, yet the manner of interconnecting projection member 14 via the piston cylinder arrangement with cap 1 1s sufficient to maintain all of the parts in the desired alignment with a minimum of stresses.

Advantageously, the forward abutment surface portion; 31 is provided at the free end of projection member 14 to permit desirable abutment with the adjacent portion of the mine face therebefore. Also, a hood portion 30, formmg a rearward extension of forward abutment surface portion 31, is provided in order to protect therewithin the appropriate portions of the piston cylinder arrangement from damage or from mine dust and dirt, considering the fact that the free end of projection member 14 is meant to be displaced outwardly with respect to cap 1 as far. as possible and in the immediate vicinity of the mine face being worked.

Utilizing a motive means such as a piston cylinder arrangement, projection member 14 may be extended from the retracted position shown in FIG. 1 to a forwardmost position even farther than that shown in phantom as aforesaid, since suitable support of the cantilever free end of projection member 14- will still be a-ttained, not only because of the retaining inter-relationship of tracks 18 and track guides 17, but also because of the fact that projection member 14 is meant to be interposed between the upper side of cap 1 and the mine roof thereabove. In fact, projection member 14, and especially the flat web central portion 15 (see PEG. 2) will be interposed in clamped disposition between cap .1 and the mine roof thereabove so long as the pit prop of mining prop arrangement is extended to place cap 1 in pressure engagement with the mine roof. Even if a great extent of projection member 14 is displaced beyond the forward end portion 12 of cap 1, suitable cantilever support of projection member 14 will be present, since the remainder of projection member 14 overlying the upper side of cap 1 will be disposed in the aforementioned clamped association between cap 1 and the mine roof.

Accordingly, the present invention provides cantilever roof cap projection members which can change their effective length in a stepless or infinite manner, whereby to adapt such length to the requirements of the particular mining operation, so as to permit in every instance a sufficiently tight pressure engagement with the mine roof thereabove.

It must be emphasized that the cantilever projection member in accordance with the instant construction is slidably guided longitudinally on the upper side of the roof cap in question with at least a portion of its length being clamped between the roof cap and the mine roof in any position of movement of the projection member with respect to the cap. By providing the projection member with a U-shaped cross section or channel cross section, such that a flat web center portion is provided which may rest upon the upper side of the roof cap, an eflicient translation of forces is possible, which is aided by the relationship of tracks and track guide means utilized. Such tracks and track guide means, because of the preferably adjustable nature thereof, may limit the vertical movement of the cap and projection member with respect to one another as well as the degree of canting of the projection member with respect to the cap.

The size of the piston cylinder arrangement utilized should be such that, under the hydraulic pressure available, the cantilever projection member can be advanced even if the mining props which bear the roof cap in question and the rear cap as well, are still maintained under supporting pressure for supporting the roof. All that is necessary is that the pressure of the mining prop arrangement be slightly relieved, whereby to permit longitudinal sliding of the projection member along the upper side of the appropriate roof cap. Since the mining prop arrangement does not have to be released completely so that the roof cap is spaced from the roof, in order to displacelongitudinally the projection member of the invention, safer working conditions are provided. Besides the fact that less danger to the workmen will occur where only slight decrease in pressure of the prop means is undertaken to permit the longitudinal displacement of the projection member, a certain amount of guidance longitudinally of the roof cap and the projection member will be enjoyed with respect to the roof, whereby to prevent effectively slippage laterally of the prop frame arrangement with respect to the roof.

As a convenient adaptation of the present invention, the feed of hydraulic fluid to the cantilever projection member piston cylinder means may be carried out in such a manner that the projection member may slide back onto the roof cap of the particular prop frame without overcoming any great resistance when the prop frame is moved ahead. In other words, even when the prop frame containing the roof cap and projection member in question, is moved ahead, the roof cap and also the cantilever projection member will contact the roof constantly with a certain predetermined pressure, and such pressure may even aid in returning the projection member to the re tracted position, depending upon the concordance of operation of the pressure fluid to the projection member piston cylinder arrangement and to the advancing piston cylinder means for the entire prop frame arrangement, and even to the pit props of such arrangement.

Since the guidance of the cantilever projection member on the upper side of the roof cap requires that such roof cap must generally be disposed somewhat lower than the rear roof cap disposed on the adjacent rear prop of the arrangement, because of the presence of the projection member, the pivot pin vertical slot opening interconnec tion arrangement is desirable. Although the prior art has used a hinged connection between the front and rear roof caps of a prop frame arrangement of the instant type, heretofore the provision for vertical slot openings within which the horizontally extending pivot pin is mounted had not been made. Besides the advantage of permitting relative vertical displacement between the front and rear roof caps, the vertical displacement joint in question permits the front and rear roof caps to be canted slightly in relation to one another, which is of importance under certain circumstances depending upon the particular disposition of the mine roof in question. A full area contact between the front and rear roof caps and the roof may be attained, therefore, under conditions where the mine roof is not entirely flat or smooth, yet where it is desirable to have as complete a support of the roof as possible. Nevertheless, stop means are provided in order to limit the canting of the front and rear roof caps with respect to one another at least in one direction, for example the downward direction, whereby to achieve a greater margin of safety of the equipment.

Advantageously, in accordance with the present invention the effective length, that is the length by which the cantilever projection member extends beyond the front edge of the roof cap in question, can be as great as desired, whereby an important practical advantage over the prior art cantilever roof support elements, usually pivotally connected to the front end of the appropriate roof cap, may be enjoyed.

Thus, in accordance with a particular embodiment of the present invention, the cap is provided with a pair of parallel laterally disposed underside tracks along the corresponding sides thereof and the projection member is provided with a corresponding pair of parallel laterally overlying and downwardly depending track guide means in retaining slidable contact with the underside tracks, to maintain the projection member within a predetermined longitudinal path of movement between the retracted and extended positions without substantial deviation from supporting contact with the cap. Preferably, the track guide means are vertically limitedly adjustable to permit limited vertical displacement thereof with respect to the tracks to provide a limited vertical spacing therebetween for adjusting the degree of deviation of the projection member from supporting contact with the cap to achieve limited relative canting between such member and such cap.

Furthermore, the present invention generally contemplates energizable reciprocating motive means, having a first motive part and a second motive part coacting interconnected with one another for limited relative longitudinal displacement with respect to each other, the first part being connected to the cap and the second part being connected to the projection member for displacing longitudinally such member with respect to the cap in an infinite range between the retracted and extended positions of the projection member upon corresponding energizing of the motive means. Preferably, the motive means comprise hydraulic piston-cylinder means as aforesaid.

Additionally, the projection member is advantageously provided with a longitudinal free end which projects beyond the adjacent longitudinal end of the cap when the projection member is moved to extended position, and the free end is provided with a forward abutment surface portion adapted to engage abuttingly a mine face therebefore. Such forward abutment surface portion extends rearwardly to form a hood for the adjacent longitudinal end of the cap in accordance with a preferred feature of the construction of the present invention, whereby to protect, for example, the piston cyilinder arrangement connected thereat.

With respect to the front and rear caps, the front cap is advantageously articulatedly coupled about a hinge connection having a transverse axis of pivot, at the longitu- :linal end thereof remote from the free end of the projection member, with the rear cap in the form of a cooperating additional roof cap to provide an extensible and articulatable longitudinal roof cap assembly. Specifically, the hinge connection includes a horizontally extending pin disposed within vertical slot means provided thereat permit displacement vertically between said pin and said slot means and in turn said cap and additional cap to accommodate unevenness in the mine floor thereabove and the vertical dimension of the projection member interposed between the upper side of the cap and such mine roof thereabove. The pin is provided, preferably, with a depending stop element disposed operatively between the adjacent portions of the undersides of the cap and additional cap at the hinge connection and normally spaced therefrom a predetermined distance when the cap and additional cap are in substantial longitudinal alignment, whereby upon downward canting articulation of the cap and additional cap with respect to each other about the transverse axis of pivot, such that the hinge connection defines an uppermost apex between the cap and additional cap with the ends of such cap and additional cap remote from the connection being disposed at a lower vertical level with respect to such apex, the depending stop element will be placed in abutment with the adjacent underside portions of the cap and additional cap to limit the angle of pivot therebetween in that direction.

Although the entire prop frame arrangement used in connection with the roof cap and projection member in accordance with the present invention is not shown, the construction of siuch parts is well known. The roof cap in question as well as the additional roof cap or rear cap articulatedly connected therewith, as well as the projection member slidably disposed in contact with the upper side of the forward roof cap in question, are meant tobe mounted on appropriate pit prop means for advancement transversely towards the mine face as newly exposed layers of mineral are extracted. By reason of the extensible nature of the projection member in accordance with the present invention, i.e. along a longitudinal path transverse to the mine face, and within an infinite range of longitudinal movement, within the practical aspects of the construction of the invention, much more complete and efiicient as well as much safer support of the mine roof at the mine face can be obtained during the time between the removal of mineral from the mine face and mine roof and the next advance of the conveyor and the mining prop roof supporting arrangements in the usual manner.

It will be appreciated that the instant specification and drawings are set forth by way of illustration and not limitation, and that various modification and changes may be made without departing from the spirit and scope of the present invention which is to be limited only by the scope of the appended claims.

What is claimed is:

ll. Mine roof support cap adapted to engage supportingly a mine roof thereabove and having situated longitudinally on the upper side thereof a cantilever roof cap projection member in upwardly overlying supporting contact therewith and movable longitudinally relative thereto between a retracted position overlying a greater longitudinal portion of said cap and an extended cantilever position overlying a lesser longitudinal portion of said cap in cantilever supported relation therewith, at least a portion of said member remaining in upwardly overlying supporting contact with said cap in any position of longitudinal movement of said member with respect to said cap, whereby when said cap is in upwardly overlying supporting engagement with the mine roof, at least a portion of said member will be supportingly interposed in clamped disposition between said cap and such roof.

2. Cap according to claim 1 wherein said cap is provided with a pair of parallel laterally disposed underside tracks along the corresponding sides thereof and said member is provided with a corresponding pair of parallel laterally overlying and downwardly depending track guide means in retaining slidablc contact with said underside tracks, to maintain said member within a predetermined longitudinal path of movement between said retracted and extended positions without substantial deviation from supporting contact with said cap.

3. Cap according to claim 2 wherein energizable reciprocating motive means, having a first motive part and a second motive part coactingly interconnected with one another for limited relative longitudinal displacement with respect to each other, are provided, said first part being connected to said cap and said second part being connected to said member for displacing longitudinally said member with respect to said cap in an infinite range between said retracted and extended positions upon corresponding energizing of said motive means.

4-. Cap according to claim 3 wherein said motive means comprises a hydraulic piston-cylinder means.

5. Cap according to claim 3 wherein said member is provided with a longitudinal free end which projects beyond the adjacent longitudinal end of said cap when said member is moved to extended position and said free end is provided with a forward abutment surface portion adapted to engage abuttingly a mine face therebefore.

6. Cap according to claim 5 wherein said surface portion extends rearwardly to form a hood for said adjacent longitudinal end of said cap.

7. Cap according to claim 5 wherein said cap is articulatedly coupled about a hinge connection having a transverse axis of pivot, at the longitudinal end thereof remote from the free end of said member, with a coopcrating additional roof cap to provide an extensible and articulatable longitudinal roof cap assembly.

8. Cap according to claim 7 wherein said hinge connection includes a horizontally extending pin disposed within vertical slot means provided thereat to permit displacement vertically between said pin and said slot means and in turn said cap and additional cap to accommodate unevenness in the mine roof thereabove and the vertical dimension of said member interposed between the upper side of said cap and such mine roof thereabove.

9. Cap according to claim 8 wherein said pin is provided with a depending stop element disposed operatively between the adjacent portions of the undersides of said cap and adidtional cap at said hinge connection and normally spaced therefrom a predetermined distance when said cap and additional cap are in substantially longitudinal alignment, whereby upon downward canting articulation of said cap and additional cap with respect to each other about said transverse axis of pivot, such that said hinge connection defines an uppermost apex between said cap and additional cap with the ends of said cap and additional cap remote from said connection being disposed at a lower vertical level with respect to such apex, said depending stop element will be placed in abutment with the adjacent underside portions of said cap and additional cap to limit the angle of pivot therebetween in that direction.

It Cap according to claim 9 wherein said first motive part is connected to the free end of said member and the second motive part is connected to said cap and wherein said cap is provided with hearing recess means on the underside thereof to accommodate the prop head of a mining prop in connection with which said cap is adapted to be used.

11. Cap according to claim it} wherein said track guide means is vertically limitedly adjustable to permit limited vertical displacement thereof with respect to said tracks to provide a limited vertical spacing therebetween for adjusting the degree of deviation of said member from 9 10 supporting contact with said cap to achieve limited re1a- FOREIGN PATENTS tive canting between said member and said cap. 1,167,165 7/1958 France References Cited by the Examiner gggg gi gi UNITED STATES PATENTS 5 915,206 1/1963 Great Britain. 3,216,202 11/1965 Seddon 61-45.2

CLAUDE A. LE ROY, Primary Examiner.

Claims

1. MINE ROOF SUPPORT CAP ADAPTED TO ENGAGE SUPPORTINGLY A MINE ROOF THEREABOVE AND HAVING SITUATED LONGITUDINALLY ON THE UPPER SIDE THEREOF A CANTILEVER ROOF CAP PROJECTION MEMBER IN UPWARDLY OVERLYING SUPPORTING CONTACT THEREWITH AND MOVABLE LONGITUDINALLY RELATIVE THERETO BETWEEN A RETRACTED POSITION OVERLYING A GREATER LONGITUDINAL PORTION OF SAID CAP AND AN EXTENDED CANTILEVER POSITION OVERLYING A LESSER LONGITUDINAL PORTION OF SAID CAP IN CANTILEVER SUPPORTED RELATION THEREWITH, AT LEAST A PORTION OF SAID MEMBER REMAINING IN UPWARDLY OVERLYING SUPPORTING CONTACT WITH SAID CAP IN ANY POSITION OF LONGITUDINAL MOVEMENT OF SAID MEMBER WITH RESPECT TO SAID CAP, WHEREBY WHEN SAID CAP IS IN UPWARDLY OVERLYING SUPPORTING ENGAGEMENT WITH THE MINE ROOF, AT LEAST A PORTION OF SAID MEMBER WILL BE SUPPORTINGLY INTERPOSED IN CLAMPED DISPOSITION BETWEEN SAID CAP AND SUCH ROOF.