US3113661A

US3113661A - Apparatus for displacing a longitudinal mining conveyor

Info

Publication number: US3113661A
Application number: US62213A
Authority: US
Inventors: Linke Horst; Rosenberg Harry
Original assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Current assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Priority date: 1959-09-09
Filing date: 1960-10-12
Publication date: 1963-12-10
Anticipated expiration: 1980-12-10

Description

Dec. 10, 1963 H. LINKE ETAL Filed Oct. 12, 1960 Fig.1

United States Patent Ofifice 3,ll3,bl Patented Dec. 10, 1963 3,113,6dl APPARATUS DidPLA ClNG A LQNQETUBENAL MTNTNG (ISNVE'iGl-i Horst Links, Lumen, and Harry Rosenberg, Dahlhruch,

Germany, assignors to Gewerhschaft Eisen'nutte Westfalia, Westphalia, Germany, a German corporation ranks on. 12, 1968, Ser. No. sears Claims priority, application Germany Sept. 9, 1959 lb Qlaims. (will. l9S-l26) The present invention relates to an apparatus for horizontally displacing a longitudinal mining conveyor and, more particularly, to such an apparatus having a first member and a second member interconnected for hon- Zontal displacement with respect to one another, one of said members being adapted to be secured to a longitudinal mining conveyor spaced from the other of said members, the other of said members including at least two mining props positioned substantially one behind the other in the longitudinal direction of the members, wherein one of said props is situated in a plane substantially perpendicular and the other of said props is situated in a plane'substantially inclined with respect to the longitudinal direction of said members.

This application is a continuation-in-part application of co-pending U.S. application, Serial No. 54,389, filed eptember 7, 1960, now Patent No. 3,072,241.

Generally, in the mining of coal and other mineral material, a planing device is often used to extract coal from the mine face. In this regard, the planing device is moved against the coal face whereby a layer or" coal is scraped from the adjacent mine wall. In order conveniently to remove the extracted coal from the site of mining operations, a longitudinal conveyor is provided adjacent to the mine face along the path of travel of the planing device.

Accordingly, as the planing device extracts the coal, by reason of the positioning of the conveyor, the coal falls thereon and is conducted from the site of mining operations.

In particular, double chain scraper conveyors are used wherein a pair of parallel endless chains are provided mounted for movement in the same direction so as to carry the coal by means of the attendant chain scraper bars along the surface or" the conveyor to a distant point of recovery. The planing device may be conveniently supported in a track disposed along the conveyor on the side adjacent to the mine face being extracted.

As each layer of coal is scraped from the mine face, the planing device must be moved forward in transverse direction so that it may engage the next layer of coal. In the same way, the conveyor must be advanced to accommodate the newly extracted com.

Various means have been used to accomplish the advancing movement of the conveyor such as by employing releasing beams which are positioned transverse with respect to the conveyor and which conduct the conveyor forward. The conveyor is slidably mounted on these beams so that the transverse movement may be executed with ease. Moreover, constructions are known in which crane carriages are positioned at the ends of the conveyor which are connected thereto by displaceable means. The known releasing means have the disadvantage that the longitudinal beam employed projects laterally far beyond the width of the conveyor and, accordingly, necessitates long and wide stalls for the mining o eration. Furthermore, in this same connection, an unduly large amount of space is required on the side of the conveyor adjacent to the mine face being extracted. Such conventional means also require a considerable expenditure of energy, since these means are often manually operated. This is especially true since the conveyor must be separately CAD released as soon as the beam itself must be advanced in order to advance, in turn, the conveyor.

-roposals have already been made to equip the conveyor with automatically advancing mining prop units or mining frames which coact in pairs to achieve the advancing of the conveyor. In the conventional manner, one frame is secured against movement and is used as support for executing the movement of the other frame and the conveyor, and thereafter the one frame is released and the other secured to continue the next advancing movement of the conveyor. Nevertheless, such conveyor and mining frame arrangement was not entirely satisfactory since the advancement of the conveyor did not take place in the desired manner but instead the conveyor was often displaced out of its normal path, either at an angle to its transverse direction of movement or to the longitudinal direction of the mine face. This necessitated stoppage of the mining operation from time to time in order to realign the conveyor and maintain it in the correct position.

Further attempts were made to develop the mining frame such that the ste -wise advancing could be carried out not only in one but in two directions. Thus, a piston cylinder arrangement was provided which permitted the two frames to advance in step-wise manner in a direction parallel with respect to one another as well as in a direction transverse or lateral with respect to one another. Thus, the conveyor could be displaced not only in transverse direction with respect to the longitudinal path of the mine face being WOl'lifid but also in longitudinal direction.

A recent development rendered possible in a simple and inexpensive manner the uniting of a mining frame arrangement with the conveyor end such that practically no space beyond the customary width of the conveyor is required. In order to adjust to the local variations in the floor and ceiling of a mine tunnel, the two mining frames had to be connected to one another in a manner different from the comparatively rigid manner in which the usual mining frames are connected.

in order to accomplish a desired connection, the conveyor end itself is provided with hydraulic pit props or mining props vertically positioned with respect to the conveyor. These pit props are attached to a swinging frame which is pivotally attached to the end of the conveyor. By arranging the axis of pivot in a direction transverse that of the conveyor, in a horizontal direction, the pit props may advantageously be used where the mine floor is uneven. A separate mining frame in this instance is attached to the conveyor end by means of a flexible strap of metal. This mining frame is similarly provided with pit props. The separate mining frame may, therefore, be secured against movement by extending the pit props into engagement with the floor and ceiling of the mine tunnel, and by means of a hydraulic cylinder and piston arrangement the pivoting frame and conveyor end attached thereto may be advanced in longitudinal direction. By providing the pivoting frame, attached to the conveyor end, with a transverse double acting piston cylinder arrangement, in the same way the conveyor may be moved in transverse direction.

It is an object of the present invention to overcome the foregoing drawbacks and to provide an apparatus for horizontally displacing a longitudinal mining conveyor with less stress on the working parts, said apparatus being constructed for efficiently accommodating itself to the changing levels of mine floor and ceiling, as the case may be.

Other and further objects of the invention will become apparent from a study of the within specification and accompanying drawings, in which FIGURE 1 represents a schematic side elevation view of an end of a longitudinal mining conveyor, including the apparatus of the invention, and

Fl-GURE 2 is a schematic plan view of the embodiment shown in FIGURE 1.

In accordance with the present invention, it has been found that an apparatus for displacing a longitudinal mining conveyor may be provided which comprises a first member and a second member interconnected by connecting means, said connecting means including means for horizontally displacing the first and second members with respect to one another. Means for releasably securing each of the members from displacement when the other member is to be displaced are also provided, such as means including extendable pit props or mining props operable by fluid pressure means in the conventional manner. One of the said members is adapted to be secured to a longitudinal mining conveyor for simultaneously displacing the conveyor as that member is displaced with respect to the other member.

Specifically, in accordance with the invention means for releasably securing each of the members from displacement with respect to the other member conveniently includes at least two mining props provided on the other of such members not connectable to the mining conveyor.

Positioned substantially one behind the other in the longitudinal direction of the first and second members, one of the two props is situated in a plane perpendicular with respect to the longitudinal direction of the first and second members, and the other of the two mining props is situated in a plane inclined with respect to the longitudinal direction of the first and second members. Suitably, the corresponding top ends of the two props are connected by a common mine ceiling cap and the corresponding bottom ends are connected by a common floor runner. The two props, the cap and the runner together form a frame. The connections of the respective ends of the two props to the ceiling cap and floor runner are flexibly or pivotally executed by means of ball and socket connections.

With respect to the member adapted to be secured to the longitudinal mining conveyor, such member conveniently carries at least one pair of pit props in a similar manner to those carried by the other member remote from the conveyor. The pit props on the one member connected to the conveyor are situated in a plane substantially inclined with respect to the longitudinal direction of the two members, such pit props defining together with the corresponding pit props on the other member the means for releasably securing each of the members from displacement when the other member is to be displaced.

Preferably, with respect to the other member not connected to the conveyor, a pair of perpendicular plane props and a pair of inclined plane props are provided such that each inclined plane prop is generally placed directly in front of each perpendicular plane prop. In this manner each inclined plane prop and perpendicular plane prop is situated in a vertical plane passing in the longitudinal direction of the conveyor. Thus, one perpendicular plane and inclined plane prop assembly is parallel to the other.

In accordance with a preferred embodiment of the invention, the inclined plane of the pair of props of the one member connected to the conveyor and the inclined plane of the inclined props of the other member are parallel.

The perpendicular plane props of the other member not connected to the conveyor are advantageously mounted upon the common floor runner thereof in a resilient pivotal manner. This may be achieved by providing spring means normally biased against pivotal displacement of the perpendicular plane props out of their perpendicular plane. A bundle of L-shaped springs may be used for the resilient urging wherein one side of the bundle is placed in abutment with the common fioor runner surface while the other is placed in abutment with a portion of the perpendicular plane prop which it serves to control resiliently.

The common mine ceiling cap may be in the form of a common connecting bar connecting one perpendicular plane prop with its forwardly adjacent inclined plane prop by means of the top end of the one perpendicular plane prop and the top end of the forwardly adjacent inclined plane prop. The bottom ends of said plane props could be suitably connected together in the same way by a commonly connected bar. By means of said connecting bars, a frame is defined together with the respective perpendicular and inclined plane props such that linear displacement of each end of one of the two props with respect to the corresponding end of the other of the two props is prevented.

he common connecting bar which may be used in the frame of the other member not connected to the conveyor may be suitably constructed as a pair of hingedly connected elements so as to accommodate unevenness in the floor or ceiling of the mine stall being worked. Thus, a transversely directed hinge connection with respect to the longitudinal direction of the conveyor may be provided between the perpendicular and inclined plane props of each frame at either the top ends or bottom ends thereof. in particular, where one frame including one perpendicular plane prop and one inclined plane prop, is connected side by side with the other frame composed of a similar perpendicular plane prop and inclined plane prop, the hinge connection between the two frames at either the corresponding top or bottom ends may be provided as a longitudinally directed hinge connection.

It will be appreciated that because of the flexible, pivotal and resilient mounting of the props in each frame of the other member not connected to the conveyor, a certain amount of displacement of the props out of their normal planes will occur due to excessive stresses placed upon the other member not connected to the conveyor when the member connected to the conveyor, for instance, is being displaced. When the member not connected to the conveyor is released from engagement with the mine ceiling and the mine door, the resilient spring means will maintain each frame in erect position and prevent more than slight displacement of the two props out of their normal planes. Since each of the frames is com nected to the connecting means maintained for horizontally displacing both or" the members with respect to one another at a point below the mid-point of the frame, the stresses placed upon the frame will tend to draw the in clined plane prop into a position such that the same will have a smaller inclined angle with respect to the vertical. correspondingly, the perpendicular plane prop will be caused to move out of its normal plane such that the same will form an inclined angle with respect to the vertical. Actuall both of the props of the frame will pivot about their top end connection points to the common ceiling cap. Since the pit props of the member not connected to the conveyor are extended to the mine fioor and ceiling due to the suitable actuation of pressure medi um in the conventional manner of hydraulic pit props, the frame will maintain its extended position, and while the perpendicular plane prop may appear to become relieved of maximum engagement via the ceiling cap and floor runner with the mine ceiling and floor, the forward inclined prop of the frame will engage such ceiling and floor with even greater force. This-is true since the resultant force of the connecting means tends to lessen the angle of the inclined plane prop, therefore causing the lower end of said prop to exert a greater force against the mine floor and, in turn, the mine ceiling, via the force against the upper end thereof.

The means for horizontally displacing the first and second members with respect to one another as aforesaid suitably include piston and cylinder means. A first piston and cylinder arrangement is mounted on one of the memhers operably connected for displacing the first and sec-' ond members with respect to one another in the longitudinal direction of the members when one of the members is secured against displacement. A second iston and cylinder arrangement is mounted on the other of the members operably connected for displacing the first and second members with respect to one another in a direction transverse the longitudinal direction of the members when one of the members is secured against displacement.

Preferably, the transverse direction displacing means includes a double acting piston mounted on a rod operably disposed within a cylinder such that the ends of the rod extend through the corresponding ends of the cylinder. Either the rod or cylinder is fixedly mounted on one of the members while the other is connected to the connecting means interconnecting the first and second members. The longitudinal direction displacement means preferably includes coacting piston and cylinder means wherein either the piston or cylinder is mounted on one member and the other is connected to the connecting means which interconnects the two members.

Generally, one member is secured from transverse movement with respect to the connecting means, yet is mounted for longitudinal movement with respect thereto, while the other member is secured from longitudinal movement with respect to the connecting means, yet is mounted for transverse movement with respect thereto. The piston cylinder means for transverse and longitudinal displacement are suitably linkably mounted on their respective members for accommodating unevenness in the mine ceiling and the mine floor.

In operation, by extending or retracting the longitudinal piston, one of the members will be longitudinally displaced since the other member is securcd against moveent by means of the pit props. On the other hand, after a first longitudinal displacement has been effected, the member which is secured against movement is released by retracting the pit props from engagement with the mine ceiling, and the member which has been displaced is now secured against movement. The opposite actuation of the longitudinal piston is carried out Whereby the further longitudinal displacement of the released member is obtained. Thus, for displacing one member with respect to the other, the member to be displaced is released from its secured position by retracting the pit props from the mine ceiling while the other member is secured by extending its pit props into abutting engagement with the mine ceiling and floor.

Concerning the transverse movement of upon securing the pit props of one member and releasing the pit props of the other, pressure fluid is passed to the transverse double acting piston cylinder arrangement whereby whichever of the piston rod or cylinder is attached to the connecting means is moved in transverse directions. As this occurs, the connecting means of the other member is correspondingly transversely displaced. Of course, whichever of the piston or cylinder is connected to the member secured against movement will remain stationary to that member. After this transverse movement has taken place, the reverse actuation may be carried out whereby the pit props of the released member are secured and the pit props of the secured men ber are released.

Thus, in particular, in accordance with the invention the perpendicular plane props of the other member not connected to the conveyor are flexibly, pivotally and preferably resiliently connected as a frame together with the inclined plane prop and the common ceiling cap and floor runner. Since in previous constructions used for this purpose, the pit props have always been rigidly connected to the ceiling cap and iloor runner, damage to the frame frequently occurred due to the excessive stresses placed upon such frames when the props were extended into engagement with the mine ceiling and floor. This is especially true where the member connected to the conveyor is sought to be displaced in longitudinal directhe members,

tion. The forces acting upon the other secured frame are so great that such other frame is somewhat displaced out of its normal position. Since the connecting means between the two members is usually positioned below the median height of the members, the load of the member connected to the conveyor causes a displacement toward the conveyor of the floor runner of the other member secured against displacement. Since rigid constructions were used, the excessive forces undesirably caused damage to or breaking of the secured separate frame.

In contrast thereto, such excessive forces are compensated for by providing flexible connections between the corresponding ends of the perpendicular and inclined plane props and the ceiling cap and floor runner. Not only will such excessive forces be prevented from damaging the prop connections, but also due to the Slight forward pivotal movement of the inclined plane prop into a less slanted position, the ceiling cap and floor runner will increase in abutting force with the mine ceiling and floor.

Referring to the drawing, a conveyor It? is shown connected to a first member 14 which carries a pair of mining props 14. The first member 14 is shown to be connected directly to the conveyor 1b. Such connection need not be integral and in order to accommodate replacement of the first member 14 or the conveyor It these members are suitably releasably connected to one another. An intermediate linking gear or connecting mans ll, 12 is provided for connecting member 1 i- Vilth a second member 13 remote from conveyor lit.

The displacement of the two

members

13 and 14 With respect to one another is eiiected in transverse direction by means of cylinder 15 stationarily attached to member 13 by means of a part 13'. Cylinder 315 coacts with a transverse piston rod 315' linlrably connected to connecting means 12. Longitudinal displacement of the two members l3 and M, on the other hand, is efiected by means of a cylinder 16- stationarily positioned at connecting means 11 wherein a piston 16' operable within cylinder 16 is movable in longitudinal direction. Piston 16' is linkably connected to connecting means 12 so that upon its movernent connecting means 12 and, in turn, member 13 will be longitudinally displaced where member 14 is secured against displacement and member 13- is released from displacement. Of course where member 14- is released from isplacement and member 13 is secured against displace ment, actuation of cylinder 16 and piston 16' will cause the displacement of member 14 and, in turn, conveyor 10*.

Cylinders l5 and 15 may be suitably actuated by a pressure medium in the conventional manner, both cylinders being preferably constructed as double acting cylinders wherein the piston may be moved in either direction upon suitable control.

In order to accommodate

members

13 and 14 and connecting means 11 and 12 therebetween to the unevenness of the mine floor and ceiling, connecting means 11 is piv ot ally connected to member 14 about the horizontally disposed pivot means ll' while piston 16' of connecting means 11 is pivotally connected to connecting means 12 about a vertical axis of pivot provided by pivot means 12'.

Member 13 includes two spaced apart vertical mining props l7 and 18 disposed in a common perpendicular plane transverse to the longitudinal direction of the members l3 and 14. On member 13, between props 17 and 1s (and member 14, are positioned corresponding mining props l9 and 20. Props l9 and 2d are both inclined in a forward vertical direction and are situated in a common plane inclined with respect to the longitudinal direction of members 13' and 14. Prop 18 and prop 29 together form a frame with

common ceiling cap

21, 22 and comanon floor runner 23.

Ceiling cap

21, 22 is a transversely hingedly connected

cap including elements

21 and 22. The hinge 28 transversely connects

elements

21 and 22 so that the ceiling cap may accommodate unevenness in the mine ceiling. In the same way, props l7 and 19' are connected by a

common ceiling cap

21, 22 and floor runner 23 to form a second frame. In one frame, prop 13 is connected at its upper end to the ceiling cap by pivot connection 24 while prop 2ft is connected thereto by pivot 25. The bottom end of prop 18 is connected to floor runner 23 by pivot 26 while the bottom end of prop 20 is connected thereto by pivot 27. In the same way, in the second frame props 1'7 and 19' are connected to the ceiling cap and the floor runner by corresponding

pivots

24, 25, 26 and 27. On the remote site of props l7 and '18 with respect to conveyor 10-, a corresponding bundle of leaf spring elements 3t) and 31 respectively is disposed. The spring elements 30', 31 are substantially L-shaped in form so that one end thereof may be placed in abutting engagement with the top surface of the floor runner 23, while the other end may be placed in abutting engagement with the rear side of the

corresponding prop

17 or 18, as the case may be. The spring elements 36* are attached to prop 17 by means of strap 32, while the spring elements 31 are attached to prop it; by means of strap 33.

While a

separate ceiling cap

21, 22 may be provided for each frame, i.e., 17, 19, 21, 22, 23 and 18, 2h, 21, 22, 2-3, a combined

ceiling cap

21, 22 may be provided for both frames which is suitably transversely hinged at 28. Of course, in order further to accommodate unevenness in the mine ceiling, the combined

ceiling cap

21, 22 may be suitably longitudinally hingedly connected as well. In this manner the ceiling cap 21, '22 of one frame is longitudinally hingedly connected to the ceiling cap of the other frame, while the rear portion of each cap is transversely it skid 29 may be provided along the forward edge of floor runner 23 where a single piece floor runner Z3 is provided, as shown in FIGURE 2. Alternatively, where the skid 29 is omitted, a separate floor runner 23-may be provided for each frame wherein such floor runner 23 may be suitably longitudinally hingedly connected as well as transversely connected in the same manner as desired above with respect to

ceiling cap

21, 22. Where hingedly connected parts are employed for the ceiling cap and floor runner, member 13 in its entirety will be able more advantageously to accommodate unevenness in the mine ceiling and the mine iioor without undue stress on the parts.

it will be appreciated that upon releasing

props

17 and 19 and props 1S and 2% from engagement with the mine ceiling and the mine door, the normal tendency of each frame to be displaced in forward direction about pivots 2d and 27 will be averted due to the presence of resilient springs 3t) and 31. It will be appreciated that the forces acting approximately in the direction of arrow 34 which are transmitted to props l7 and 13 by

props

19 and 20 via

cap

21, 22, are not nearly large enough to overcome the resistance of springs 38, 31 which resiliently oppose any displacement of props l7 and 18 out of their normal perpendicular plane. Nevertheless, springs 30, 31 do not prevent slight tilting about pivots 26 of props 1'7 and 1b; which may occur, for example, because of the forces transmitted from the conveyor ill and member lid onto member 13 during the displacement of member 14 and conveyor 10 where member 13 is secured against displacement. Such forces may certainly overcome the perpendicular or vertical position of props l7 and 1.8 when in extended position, but no damage will occur to member 13 since props l7 and 18 are pivotally mounted at 24 and 26 on their respective frames with props l9 and Ztl. It will be appreciated that while the tractive forces normally exerted onto the mine ceiling and floor via the rear portions of the ceiling cap and floor runner due to the extended position of

props

17 and 13 are diminished where the excessive pulling forces exerted on member 13

cause props

17 and 13 to pivot about pivots 24 so as to release somewhat the maximum engagement forces of props l7 and 18, simultaneously with the release of such maximum engagement forces props 19 connected at 2'3 with the forward portion of each and 2t? are caused to pivot about pivots 25 in a forward direction from a more inclined position to a less inclined position. The movement to a less inclined position will naturally result in the further exertion of tractive forces via props l9 and 2% against the forward portions of the ceiling cap and floor runner and, in turn, against the mine ceiling and mine floor.

Thus it will be appreciated that an essential feature of the invention in accordance with one embodiment thereof is to provide pivotal connections between the mining props of the frames of the member not connected to the conveyor so that when applying excessive forces to these frames, the same will be able to accommodate such forces in a flexible manner so as to prevent damage or breaking of the frames. A further feature embodies the use of leaf spring bundles or other resilient means to normally prevent the tilting of the perpendicular prop of each frame when each frame is released from engagement with the mine ceiling and floor. Naturally, the use of an inclined prop together with a vertical prop results in the maxi: mum efliciency of reinforcement when the member is secured against displacement.

What is claimed is:

1. Apparatus for displacing a longitudinal mining conveyor which comprises a first member and a second member interconnected by connecting means, said connecting means including means for horizontally displacing said first and second members with respect to one another, means for releasably securing each of said members from displacement when the other member is to be displaced, one of said members being adapted to be secured to a longitudinal mining conveyor for simultaneously displacing said conveyor as said one member is displaced, said means for releasably securing each of said members from displacement including prop means provided on said one member and at least two mining props provided on and flexibly secured to the other of said members and positioned substantially one behind the other in the longitudinal direction of the first and second members, one of said two props being normally operatively situated in a plane substantially perpendicular and the other of said two props being normally operatively situated in a plane substantially inclined with respect to the longitudinal direction of said first and second members.

2. Apparatus according to claim 1 wherein said prop means on said one member includes a pair of inclined props situated in a plane substantially inclined with respect to the longitudinal direction of said first and second members, the inclined plane of the pair of inclined props of said one member and the inclined plane of the prop of said other member being parallel, said means for horizontally displacing said first and second members with respect to one another including piston and cylinder means.

3. Apparatus according to claim 1 wherein the perpendicular plane prop of said other member is resiliently pivotally mounted on said other member, and spring means are provided on said other member to normally bias against pivotal displacement said perpendicular plane prop out of said perpendicular plane, the two props of said other member being directly one behind the other in said longitudinal direction and provided with a common connecting bar at each corresponding end to prevent linear displacement of each end of one of said two props with respect to the corresponding end of the other of said two props, the ends of each of said two props being pivotally connected to the corresponding common connecting bar thereat.

4. Apparatus according to claim 3 wherein two additional props one behind the other are provided on said other member correspondingly parallel to said first mentioned two props on said other member, said two additional props being provided with a common connecting bar at their corresponding top ends parallel to the common connecting bar at the corresponding top ends of said first mentioned two props, each of the common connecting bars at said top ends being defined by two transversely hingedly connected elements with respect to said longi tudinal direction.

5. Apparatus according to claim 4 wherein said means for horizontally displacing said first and second members with respect to one another comprises piston and cylinder means, said piston and cylinder means including a first piston and cylinder arrangement operably connected for displacing said first and said second members with re spect to one another in the longitudinal direction of said members when one of said first and second members is secured against displacement and a second piston and cylinder arrangement operably connected for displacing said first and second members with respect to one another in a direction transverse said longitudinal direction when one of said members is secured against displacement.

6. Apparatus for displacing a longitudinal mining conveyor which comprises a first member having transverse displacing means and a second member having longitudinal displacing means, connecting means interconnecting said first member with said second member for longitudinally displacing said first and second members with respect to one another by said longitudinal displacing means and for transversely displacing said first and second members with respect to one another by said transverse displacing means, means for releasably securing each of said members for displacement when the other member is to be displaced, one of said members being adapted to be secured to a longitudinal mining conveyor for simultaneously displacing said conveyor as said one member is displaced, said means for releasably securing each of said members including at least two mining props provided on and flexibly secured to the other of said members and positioned substantially one behind the other in the longitudinal direction of said members, one or" said two props being resiliently pivotally situated in a plane substantially perpendicular and the other of said two props being normally pivotally situated in a plane substantially inclined with respect to the longitudinal direction of said members, said resiliently pivotally situated prop being normally biased against pivotal displacement out of said perpendicular plane.

7. Apparatus according to claim 6 wherein the perpendicular plane mining prop is a vertical prop and the inclined plane mining prop is an inclined prop inclined toward the conveyor, said vertical and inclined props being pivotally connected at both their corresponding top and bottom ends to common connecting means, the inclined prop being closest to said one member and said vertical prop being resiliently pivotally mounted at its bottom end to said connecting means and normally biased against pivotal displacement.

8. Apparatus according to claim 7 wherein said common connecting means comprise a common mine ceiling cap at the top ends and a common floor runner at the bottom ends.

9. In an apparatus for displacing a longitudinal mining conveyor having a first member having transverse displacing means and a second member having longitudinal displacing means, connecting means interconnecting said first member with said second member for longitudinally displacing said first and second members with respect to one another by said longitudinal displacing means and for transversely displacing said first and second members with respect to one another by said transverse displacing means, and means for releasably securing each of said members from displacement when the other member is to be displaced, one of said members beingadapted to be secured to a longitudinal mining conveyor for simultane ously displacing said conveyor as said one member is displaced, the improvement which comprises said means for releasably securing each of saidmembers including at least two mining props provided on the other of said members positioned substantially in tandem in the longitudinal direction of said members, one of said two props being resiliently pivotally mounted on said other member and situated in a plane substantially perpendicular and the other of said two props being situated in a plane substantially inclined with respect to the longitudinal direction of said members, spring means being provided on said other member normally biasing said one prop against pivotal displacement out of said perpendicular plane.

It). In a mining arrangement including a longitudinal mining conveyor, first mining prop means secured to said conveyor for engaging opposing support surfaces to prevent displacement of said conveyor, second mining prop means spaced from and linkably connected to said conveyor for similarly engaging opposing support surfaces, and means for horizontally displacing said conveyor and said second mining prop means with respect to one another, the improvement which comprises providing as said second mining prop means frame means including flexibly secured thereon at least two upright mining props positioned substantially one behind the other in the longitudinal direction of said conveyor, said props being secured at their lower ends to said frame means to prevent linear displacement of said ends with respect to one another, one of said two props being situated in a plane substantially perpendicular and the other of said two props being situated in a plane substantially inclined with respect to said longitudinal direction for engaging opposing support surfaces to prevent displacement of said frame means, the perpendicular plane prop being resiliently biased against displacement out of said perpendicular plane and being linkably connected at its upper end to the upper end of the inclined plane prop to prevent linear displacement of said ends with respect to one another, said frame means being spaced from and linkably connected to said conveyor.

References Cited in the file of this patent UNITED STATES PATENTS 2,910,281 Wilkenloh et al. Oct. 27, 1959 FOREIGN PATENTS 879,242 Germany June 11, 1953 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,113,661 December 10, 1963 Horst Linke et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5 line 54, for "directions" read direction column 9, line 27, for "for displacement" read from displacement Signed and sealed this 28th day of April 1964.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents