US3434389A - Automatic sequence cycle controlled advanceable mining prop arrangement - Google Patents

Description

March 25, 1969 HANS-THEODOR GRISEBACH 3,434,39

AUTOMATIC SEQUENCE CYCLE CONTROLLED ADVANCEABLE MINING PROP ARRANGEMENT Original Filed Jan. 19, 1966 i Sheet of 2 INVENTOR HANS-THEUUUR smsaama March 25. 1969 HANS-THEODOR GRISEBACH 3,434,389

AUTOMATIC SEQUENCE CYCLE CONTROLLED ADVANCEABLE MINING PROP ARRANGEMENT Original Filed Jan. 19, 1966 Sheet of 2 INVENTOR HANS'THEUIJOR GRISEBAEH United States Patent Oihce 3,434,389 Patented Mar. 25, 1969 3,434,389 AUTOMATIC SEQUENCE CYCLE CONTROLLED ADVANCEABLE MINING PROP ARRANGEMENT Hans-Theodor Grisebach, Cappenberg, near Lunen, Germany, assignor to Gewerkschaft Eisenhutte, Westfalia, Wethmar, near Lunen, Westphalia, Germany Continuation of application Ser. No. 523,502, Jan. 19, 1966. This application Sept. 29, 1967, Ser. No. 671,896 Claims priority, application Germany, Jan. 21, 1965, G 42,622; Feb. 27, 1965, G 42,952 Int. Cl. EZld 15/16, 15/44; Ftllb 31/12 U.S. Cl. 9136 31 Claims ABSTRACT OF THE DISCLOSURE Advanceable mining prop arrangement with hydraulically actuata'ble motive means controlled by motive valve means, with each prop being hydraulically actuatable to change its eflective length for alternate extension into and retraction from supporting engagement with the mine roof and mine floor upon hydraulic actuation, in combination with automatic sequence valve control means operatively connected with the motive valve means, such sequence valve control means, for example, being separately positioned at a remote distance from the prop unit sufliciently to permit switching of the sequence valve control means without danger to the operator from the resultant changes in condition of the prop unit and the mine roof area being supported thereby, said control means so combined with timing means as to operate them in an automatic timed cycle operation.

This is a streamlined continuation application of copending parent application Ser. No. 523,502, filed Jan. 19, 1966, now abandoned.

The present invention relates to an automatic sequence cycle controlled advanceable mining prop arrangement, and more particularly an advanceable mining prop arrangeme'nt having a pair of mining props interconnected by motive means for alternate actuation to advance the arrangement, in combination with automatic sequence valve control means operatively connected with the valve means of the mining prop arrangement for regulating the corresponding pressure fluid flow therethrough in predetermined ordinal sequence and for predetermined intervals in an automatic cycle operation whereby to advance the mining prop arrangement automatically, preferably from a remote control point.

Mining prop arrangements are known which are usually used in connection with a conventional mining conveyor whereby to guide a mining machine, such as a mining planer, along the mine face for the extraction of mineral therefrom, with the conveyor and in turn the mining machine associated therewith being advanced in increments or in a more or less continuous manner under the urging force of an advancing cylinder, i.e., doubleacting piston-cylinder means, or by means of the mining prop arrangement associated with the conveyor for supporting the mine roof at the site of mining operations. Various constructions of the foregoing type are known in the art as may be appreciated from US. 'Patents 2,691,- 514; 2,702,697; 2,745,651; 3,169,377; 3,174,289; 3,186,- 179, and 3,192,722. In particular, a mining prop arrangement is shown in the aforesaid US. Patent 3,192,722,

which includes a pair of prop frames, each including a pair of extensible and retractable mining props interconnected at their heads and feet by a roof cap and base respectively, with such frames being operatively interconnected by a piston-cylinder means, such that upon energizing the piston-cylinder means in a first step, the prop frame connected to one of the moving parts is advanced whereupon energizing in the second step results in the advance of the other frame connected to the other part. Of course, when a particular prop frame is to be advanced, the same is retracted from engagement with the mine roof.

Mining prop arrangements of the foregoing types have been provided in many embodiments, but in the usual instance the prop units, composed of a pair of prop frames operatively interconnected by a piston-cylinder means, are actuated via manually operated valves. These are generally combined in a control block in such a manner that the retracting of the props of the particular prop frame to be advanced, the advancing of such prop frame by energizing the piston-cylinder means and the extension of the advanced prop frame to place the roof cap thereof in supporting engagement once more with the mine roof, must be carried out individually by hand.

Despite the usual manual control for the advancing of a prop unit composed of a pair of prop frames interconnected by piston-cylinder means, hydraulic, pneumatic and electrical transmission means have been utilized nevertheless for attaining the same type of actuation of the prop unit parts from a central point in the case where large groups of prop units are intended to be operated simultaneously or for that matter all of the prop units in a particular mine area being Worked. To attain such central control, however, understandably, long cables or transmission lines must be utilized to reach the multiple number of prop units in question, and this results in great expense not only for the cables and/or lines and the complicated control equipment required but also in terms of damage to the cables and/or lines as well as to the complicated equipment, considering the comparatively rigorous treatment to which such elements are subjected un der normal mining operations.

It has also been proposed to employ so-called manipulators, i.e., portable remote control central units, which remotely control a given groupof mining prop units.

In all constructions and arrangements used heretofore, however, any control, especially remote control of the advanceable mining prop arrangement and concomitantly of the positioning of the mining machine and/or the conveyor, etc, has been undertaken by equipment which could only control the individual steps or functions in a given prop unit, rather than automatically in a timed cycle, all of such steps or functions following one another without further control. For this purpose, wireless transmitters and the like have been used at a remote point for controlling, via a receiver, control means installed in a mining machine or other equipment utilized in the mining operations to accomplish the particular actuation desired.

Particularly, the transmitter is adjusted at a different frequency or pulse to control a given advancement individual function or step, such as in a mining prop unit. Such mining prop unit concomitantly would have receiver means associated therewith receptive to the different frequencies or pulses of the transmitter whereby to control an individual function or step in the operation of the mining prop unit in dependence upon the selected frequency. Understandably, the fruition of the foregoing involves relatively complicated transmitters and receivers and even the results are not completely effective.

In this connection, it must be realized that in order to advance a given mining prop unit, such as one of the type shown in U.S. Patent 3,192,722, mentioned above, firstly one prop frame must be retracted from engagement with the mine roof, while the other prop frame remains engaged therewith, secondly the one movable part of the piston-cylinder means which is connected to such one prop frame is then advanced in the desired direction to advance in turn the one prop frame, thirdly such one prop frame is extended once more into engagement with the mine roof, fourthly the other prop frame is retracted from engagement 'with the mine roof, fifthly the moving part of the piston-cylinder means connected to such prop frame is energized to advance such part in the desired direction and in turn to advance such other prop frame, and sixthly such other prop frame is extended once more into engagement with the mine roof. Each of such six steps has been controlled heretofore by a separate frequency where a remote control transmitting equipment has been used in connection with a corresponding receiving equipment, the receiving equipment being located near or on the individual prop unit. Any such proposals heretofore suggested for the automatic control of the mining equipment at the mine face, such as the advanceable prop units, etc., have contemplated automatic control in the sense that completely automatic control was utilized with concomitant disregard for the normal variations to be encountered in mining operations. Specifically, the mine face conditions, the skill of the personnel, as well as the technical conditions of the mine roof and of the advanceable prop frame unit itself, are such that under the present conditions of development completely automatic control for extracting mineral from the mine face is far from advisable or attainable. At present, it is still necessary for the operating personnel to pass along from mining prop frame unit to mining prop frame unit in order to carry out the immediate supervision of the automatic operations being undertaken, despite the fact that such operations are intended to be automatic. This is to permit minor, yet important, adjustments to be made in the disposition of the mining prop units, the conveyor associated therewith, etc. For the most part, completely automatic mining equipment, and especially advanceable mining prop units, utilizing various remote controls, are still too costly for widespread use, and the sensitivity of the equipment renders the application thereof extremely limited considering the normally adverse and rigorous conditions met in mining operations.

In the case of the usual individual manual control, the operator must in each instance remain at the mining frame unit until the complete advance of the unit has been completed. However, it is just during this advancing operation of the unit that a special zone of danger is present in the region of the unit being advanced, since during such advance the roof thereabove frequently caves in. This is understandable since in the advance, a portion of the roof is robbed of support to permit a particular mining prop frame to be displaced by the piston-cylinder means. It has thus been proposed to arrange the control block carrying the switches for the valves to energize the unit for the desired purposes, not on the particular frame or unit whose advance is to be controlled thereby but on the neighboring frame or unit. This will permit the operator to withdraw from the direct zone of danger during the advancing steps.

It is an object of the present invention to overcome the foregoing drawbacks and to provide an automatic sequence cycle controlled advanceable mining prop arrangement.

It is another object of the present invention to provide an advanceable mining prop arrangement having a pair of mining props interconnected by motive means for alternate actuation to advance the arrangement, in combination with automatic sequence valve control means operatively connected with the valve means of the mining prop arrangement for regulating the corresponding pressure fluid flow therethrough in predetermined ordinal sequence and for predetermined intervals in an automatic cycle operation whereby to advance the mining prop arrangement automatically, preferably from a remote control point.

It is still another object of the present invention to utilize automatic control means which permit the retraction advancement, and extension of one prop frame of the prop unit followed by the retraction, advancement and extension of the other prop frame of the prop unit in an automatic manner, with the steps being in ordinal sequence and with the control being for predetermined periods of time, so that the over-all advancement will be accelerated as compared with the time required heretofore for manual advancement of a prop unit, or previously utilized remote control advancement.

It is still another object of the present invention to provide control means of the foregoing type for a plurality of mining prop frame units disposed along the mine face for the simultaneous and/or successive advancement of such units to reduce the time interruption between successive passes of the mining machine along the mine face in order to accomplish more economically and more efficiently the extraction of mineral.

It is still another object of the present invention to carry out the automatic advancement of one or more mining prop frame units in such a manner there is no longer any danger to the operator of the control equipment as heretofore occurred, and in such a manner that the operator is accorded greater mobility of movement at the mine site whereby to attend to other duties once a. particular control for the automatic advancement of a prop unit has been initiated.

It is a further object of the present invention to provide a combination of control elements together with an advanceable mining prop frame unit in a durable and inexpensive manner, the arrangement contemplating simple and inexpensive elements of construction, and readily replaceable parts.

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 an enlarged schematic top view of an automatic sequence valve control means utilized for controlling a prop frame unit in accordance with the present invention; r

FIG. 2 is a schematic top view of a plurality of individual prop frame units disposed in side by side relation with each having an automatic sequence valve control means in accordance with the present invention assigned thereto, such sequence valve control means being operatively interconnected for controlling the advancement of the particular units in a given predetermined sequence;

FIG. 3 is a schematic view of an alternate manner of controlling the switch means for initiating the operation of the automatic sequence valve control means of the invention;

FIG. 4 is a schematic side view of a prop frame of an advanceable mining prop frame unit in accordance with the present invention having wireless receiving means thereon for controlling the advancement of the unit; and

FIG. 5 is an enlarged schematic perspective view of a particular embodiment of the automatic sequence valve control means of the present invention which is controlled remotely by a wireless transmitting device.

It has now been found in accordance with the present invention that an advanceable mining prop arrangement which comprises an advanceable prop unit including hydraulically actuata'ble motive means having a first motive part and a second motive part operatively interconnected for back and forth alternate longitudinal displacement with respect to each other upon corresponding alternate hydraulic actuation, motive valve means controlling such alternate hydraulic actuation, prop means including a first prop connected to said first motive part for longitudinal displacement therewith and a second prop connected to said second motive part for longitudinal displacement therewith, each said prop being hydraulically actuatable independently of the other to change the effective length thereof for alternate extension into and retraction from supporting engagement with the mine roof and mine floor upon corresponding alternate hydraulic actuation, and first prop valve means for said first prop and second prop valve means for said second prop correspondingly controlling such alternate hydraulic actuation, in combination with automatic sequence valve control means operatively connected with said motive valve means, first prop valve means and second prop valve means to actuate said valve means for regulating the corresponding hydraulic flow therethrough in predetermined ordinal sequence and for predetermined intervals in an automatic cycle operation, said sequence valve control means being switchable from an inactive condition to an active condition wherein, when both said props are extended into engagement with the mine roof, said sequence valve control means in sequence automatically firstly actuates said first prop valve means for retraction of said first prop from engagement with the mine roof, secondly actuates said motive valve means for longitudinal displacement of said first motive part and said first prop with respect to said second motive part and said second prop in a given longitudinal direction of advance, thirdly actuates said first prop valve means for extension of said first prop into engagement with the mine roof, fourthly actuates said second prop valve means for retraction of said second prop from engagement with the mine roof, fifthly actuates said motive valve means for longitudinal displacement of said second motive part and said second prop with respect to said first motive part and said first prop in said direction of advance, and sixthly actuates said second prop valve means for extension of said second prop into engagement with the mine roof, may be advantageously provided.

Preferably, supplemental manual switch means are provided in operative association, separately from said sequence valve control means, with said motive valve means, first prop valve means and second prop valve means to permit alternative manual actuation of said valve means. Also, it is expedient to provide the sequence valve control means at a remote distance from the prop unit in question to permit control without danger to the operator from resultant changes in condition of the prop unit and the mine roof area being supported thereby.

In particular, the sequence valve control means include an automatic timer device which when switched from inactive to active condition passes through a timed cycle to control the actuation in turn of said valve means in the required sequence, preferably with the timer device passing through a pre-active condition of pre-set duration prior to attaining the active condition, as a safety delay period to permit the operator to leave the immediate prop unit site before the resultant changes in condition of such prop unit and the mine roof area being supported thereby occur upon the timer device attaining the active condition.

Such timer device may include a control block having a dial face with valve means switch contacts to control the corresponding hydraulic flow through the various valve means and a sweep-hand switch contact movable from a starting position, preferably initially through a pre-active portion of the dial for attaining the pre-active condition of pre-set duration and thence, through the active portion of the dial in contact for predetermined intervals in time controlled sequence ordinally with the valve contacts to achieve the automatic advancement of the prop unit in question.

Furthermore, the automatic timer device may include a drive linkage operatively connected with displaceable cam means and cam actuatable response means operatively connectable with the valve means to control the correspondingly hydraulic flow therethrough, with the drive linkage being energizable to displace the cam means to actuate follower means forming a part of the response means to thereby control the valve means.

The automatic timer device, whether utilizing a control block dial and sweep-hand switch contact or a drive linkage cam means, cam actuatable response means, etc., may be operated by a clock mechanism, such as a spring driven or electrically driven clock mechanism, or an electrical motor, or similar connection means, so as to attain upon switching from inactive to active condition a predetermined duration automatic cycle for ordinal sequence switching of the various valve means to attain the advancement of the prop unit in question.

Understandably, a plurality of advanceable prop units of the instant type, each in combination with a respective automatic timer device, may be provided in succession in operative adjacency for the simultaneous and/or successive operation of the timer devices via cable means for the successive and/or simultaneous advancement of the various prop units in the group.

Of course, remote control means may be provided in connection with the automatic timer device of the present invention to switch the same on and off whereby to attain the inactive and active conditions thereof, such remote control means contemplating in particular a pulse signal transmitting wireless device remote from the mining prop arrangement and a pulse signal receiving wireless device operatively connected with the appropriate timer device to actuate the same upon the pulses received. The energy for carrying out the foregoing may be provided by bat teries associated with the particular prop frame unit or by spring energy, such as a coil spring in wind-up clock- Works, or the like.

As will be realized as well, where utilized herein, i.e., both in the specification and claims, the term hydraulic is meant to cover pressure fluid or pressure fluid operated equipment whether per se hydraulic or pneumatic, or the like.

Referring to the drawings, FIG. 1 shows an automatic timer device in accordance with one embodiment of the present invention including a control block 1 having an adjustable short-time clockwork 2 therein with an adjustment disc or dial face 3 on the upper side thereof along which sweep hand 4 carried by spindle 5 travels such that the sweep hand switch contact 6 traces a circular path about spindle 5 as axis along the dial face 3. The free end 7 of sweep hand 4 is provided with an oblique surface 8. Adjacent one portion of the dial face 3, a releasable locking member 9 is provided which contains the long arm 10 and the short arm 11, locking member 9 being pivotable about pivot 12 on control block 1. A Bowden cable or the like is provided adjacent locking member 9, including the flexible tube 13 and the flexible cable 15 disposed therewithin for axial displacement therewithin, cable 15 having a pushpin 14 adjacent the short arm 11 of locking member 9, whereby upon projection of pushpin 14 outwardly through the corresponding end of tube 13 locking member 9 will be released to permit sweep hand 4 to initiate its movement in the direction of arrow 16. Upon completion of the sweep hand movement around dial face 3, the same reaches the end position stop 17.

In accordance with a preferred embodiment of the present invention, a similar Bowden cable is provided at the end position stop 17 on control block 1 including the flexible tube 13 and the flexible cable 15' axially displaceable therewithin and having at the outer end thereof a pushpin 18. Thus, when the sweep hand 4 reaches end position stop 17 oblique surface 8 will strike pushpin 18 forcing the corresponding cable 15 inwardly within tube 13. In this connection, the other end of the cable 15 is arranged at a successive control block of the type in question with an appropriate pushpin for controlling the releasable locking member thereat similar to the locking member 9 adjacent the pushpin 14 shown in FIG. 1. Hence, a plurality of timer devices in accordance with the present invention may be started successively after the sweep hand of the prior control block of a previous timer device has reached its end position stop. This is seen more clearly from FIG. 2.

In connection with a particular feature of the embodiment shown in FIG. 1, the spindle may be connected with a clockwork, either electrically energized or energized by a loaded spring, such as a coil spring conventionally used for wind-up clocks. In the latter instance, the sweep hand 4 may be turned manually in the direction of arrow 19 to place the same behind the long arm of the locking means 9 until locking means 9 is released for the next actuation desired. Of course, if spindle 5 is operated electrically, then stop 17 may be releasably arranged to permit the sweep hand 4 to pass by the same to the initial starting position, wherupon by suitable energizing of the electric motor or similar means used for driving the same, the sweep hand may be used again for the complete sweep of the entire face. Locking member 9 may be appropriately modified or omitted in the case where electrical motor means are used to rotate spindle 5, and/ or sweep hand 4 may be attached to spindle 5 in a sliding friction manner to permit the simple adjustment of the sweep hand with respect to spindle 5 in the same way as the hands of a clock may be rotated on the spindle while the spindle is held from rotation.

In the usual case, upon release of locking means 9 to start the sweep of sweep hand 4 along dial face 3, the sweep hand passes through a preactive portion 20 of the entire face to achieve a preactive condition of the timer device, i.e., a delay period which will permit the operator to remove himself from the immediate vicinity of the mining prop unit before the advance to ensure his safety. The preactive period may be adjusted in a given manner by adjusting the inactive portion of sweep hand 4 closer or farther from stop 17, utilizing indicia provided on dial face 3 for measuring the time delay desired. As will be understood by the artisan, the locking member 9 may be arranged such that the same may be positioned at various places closer to or farther from stop 17 or control block 1 to achieve a corresponding variation in the time delay permitted during the preactive condition of the sweep hand 4. Once sweep hand 4 has moved from inactive through preactive condition, the same arrives at the active portion 21 of dial face 3 containing the six valve switch contacts 22, 23, 24, 25, 26 and 27, which are ordinarily positioned on the dial face and operatively connected by means not shown with the motive valve means, first prop valve means and second prop valve means of a particular prop unit to achieve upon individual contact with switch contact 6 of sweep hand 4 the actuation of the appropriate valve for a predetermined interval in a time controlled ordinal sequence. While the actual valve means are not shown, as the artisan will appreciate, these elements are conventional and the timer device including control block 1 merely acts as an automatic time control selective mechanism to complete the cycle of actuation by any means such as servomotors or the like, relating to the retraction of the first prop frame, advancement thereof, extension of such first prop frame, retraction of the second prop frame, and advancement thereof, followed by extension of such second prop frame to attain the original fully supported condition of the prop unit.

As may be seen more clearly in FIG. 2, the combination of the timer device of the present invention in the form of a control block In with an advanceable mining prop unit 39a is shown, the prop unit comprising generally one prop connected with one part of the motive means with the other part of the motive means being connected with another prop, so that upon retracting the one prop and advancing the same by the motive means connected therewith, such one prop may be extended once more for the engagement with the mine roof and the other prop can be retracted, then advanced with the motive part to which the same is connected, followed by extension of such prop once more. Specifically, the frame unit 39a includes frames 29a and 37a interconnected via the motive means 33a with control block 1a having the adjustable short-time clock-work or similar mechanism 2a situated therein for achieving the time sequence automatic control of the valve means in question as discussed more fully in connection with the operation of the control block of FIG. 1. Frame 29a contains base 28, preferably of resilient material so that the same may accommodate unevenness in the mine floor, as well as a pair of upright props 30 attached to base 28, and preferably with a roof cap (not shown) interconnecting their upper ends in the conventional manner. The motive means 33a contains the double-acting piston (not shown) carried by the piston rod 32 and the double-acting cylinder 34 through the ends of which the corresponding ends of the piston rod 32 extend. The ends of piston rod 32 are connected by straps 31 with base 28 while cylinder 34 is connected by straps 35 with base 36 of frame 37a. Frame 37a contains props 38 extending upwardly from base 36, preferably provided with a roof cap (not shown) in the same manner as props 30.

Accordingly, frames 29a and 37a are similar in construction, with the props 3t and 38 being of the usual type, utilizing the hydraulic jack principle to extend and retract such props for engaging and retracting the same from engagement with the mine roof thereabove, i.e., either directly or through the intermediary of an appropriate roof cap disposed thereat. Preferably, not only the bases 28 and 36, but also the straps 31 and 35, are made of resilient material to permit the same to be deformed somewhat in order to allow the individual prop frames and the composite prop unit 39a to accommodate unevenness in the mine floor and the mine ceiling.

Considering the use of a control block of the type shown in FIG. 1, upon passage of sweep hand 4 to the first switch position contact 22, the control valve for the hydraulic actuation of props 30 is actuated (by conventional means not shown) to retract props 30 from engagement with the mine roof. When sweep hand 4 reaches second switch position contact 23, the control valve for actuating the motive means 33a is energized to advance in the longitudinal direction toward the right, as viewed in FIG. 2, the piston and accompanying piston rod 32 whereupon prop frame 29a, now released from engagement with the mine roof, will be advanced therewith with respect to the position of frame 37a. When sweep hand 4 reaches third switch position contact 24, the control valve for props 30 will cause the extension of such props once more into engagement with the mine roof. When sweep hand 4 reaches fourth switch position contact 25, the control valve (not shown but of conventional type) for actuating props 38 will be energized to cause retraction of props 38 from engagement with the mine roof. When sweep hand 4 reaches fifth switch position contact 26, the opposite portion of the motive means 33a will be energized so as to force cylinder 34 in the same forward direction to the right, as viewed in the drawing, thus advancing as well prop frame 37a with respect to prop frame 29a. When sweep hand 4 reaches sixth switch position contact 27, the control valve for props 38 will once more extend such props into engagement with the mine roof.

Thus, by a simple timer device, an automatic cycle may be used to accomplish the six above-mentioned steps for advancing a prop unit composed of a pair of prop frames interconnected by a motive means, such as a double-acting piston cylinder arrangement. The construction of such an arrangement is conventional as may be appreciated, for instance, from a study of the aforementioned US. Patents 3,192,722, 3,174,289, and 3,186,179.

The timer device of the present invention, as aforesaid, may be a spring operated clockwork or an electrically operated motor, or the like. In accordance with a preferred feature of the present invention, more than one prop frame unit may be advanced automatically successively or simultaneously, whereby to reduce the total time of setting up the arrangement for a particular further sweep of the mining machine in question along the mine face being worked. Thus, as seen in FIG. 2, the mining prop units 3912, 39c, 39d, and 39e are provided as a group with unit 39a, each having an appropriate timer device in the form of a control block 1b, 1c, 1d, and 1e respectively, as well as an appropriate motive means in the form of a double-acting piston cylinder arrangement interconnecting the adjacent prop frames, for instance as shown by motive means 33!) and prop frames 29b and 37b of prop frame unit 39b. The appropriate adjustable short- time clockworks 2a, 2b, 2c, 2d, and 2e of the corresponding control blocks are operatively interconnected in the embodiments shown in FIG. 2 for successive actuation of the prop units, one after the other, utilizing the preferred arrangement of Bowden cable connections discussed with regard to FIG. 1 above. Thus, the Bowden cables 13a, 13b, 13c, and 13d operatively interconnect the corresponding clockworks so that upon the particular sweep hand 4 of a previous clockwork reaching the end position stop, the oblique surface of such sweep hand will push via the appropriate pushpin the flexible cable adjacent thereto inwardly to cause the other end of such cable to release the locking means of the next successive clockwork on the next successive prop frame unit. The particular details may be appreciated more fully from a study of FIG. 1 wherein the tube 13 is connected with a previous control block in the succession while the tube 13' is connected with a subsequent control block in the succession.

An alternate embodiment of the present invention in FIG. 3 contemplates a successive or even simultaneous control of the switching means for the various timer devices of successively adjacent prop frame units (not shown) of a group meant to be controlled. The cable 94 is appropriately mounted for longitudinal displacement and carries thereon a thickened portion or lu-g 95 which is meant to coact with an appropriate arm 97 or 98 of a control lever 96 used to actuate directly or indirectly the timer device of a particular prop frame unit. Schematically considering the prop frame units 39a through 39:! inclusive, as containing control levers 96a-96d inclusive, respectively, the advancement of the prop units may be attained successively upon the longitudinal displacement in a downward direction, of cable 94, as viewed in the drawing, so that the lug 95 successively actuates control levers 96a-96d via the appropriate arms 98a- 98d inclusive, or in the opposite direction via arms 97a- 97d inclusive. This alternate embodiment may include a plurality of separate cables 94 arranged to control a plurality of successive prop frame units, so that the first unit in each separate series may be actuated simultaneously, then the next, and so on, until the last prop frame unit in each group is actuated. Moreover, by utilizing a plurality of lugs 95 on the same cable 94 at spaced apart distances therealong, simultaneous as well as successive actuation of various prop frame units may be attained. Specifically, the first, eleventh, twenty-first, thirty-first, etc., prop frame units in the series may be actuated simultaneously by an appropriate switching means of the type shown in FIG. 3 upon displacement of cable 94 to bring the adjacent lug 95 into controlling contact with the control levers of the first, eleventh, twenty-first, thirty-first, etc., prop frame units. After such prop frame units have been simultaneously advanced, then the second, twelfth,

twenty-second, thirty-second, etc., prop frame units may be advanced, and so on, in succession, until the last set of prop frame units has been actuated. Suitable means, conventional in the art, may be used to prevent the further displacement of cable 94 and lu-g 95 until the completion of the advancement cycle of a previous prop frame unit, i.e., before the next prop frame unit in succession is to be actuated and advanced. Better control over the operation is attained thereby and in the event of an unsuccessful advance, the reasons for the mishap may be ascertained more readily.

In connection with a further embodiment of the present invention, as shown in FIGS. 4 and 5, a prop frame is provided which includes the upright props 41 and 42 interconnected by the resilient base strap 44 and the roof cap 43. Frame 40 is similar in construction to the individual prop frames shown in FIG. 2 and the props utilize the hydraulic jack principle to change their effective length whereby to extend such props and in turn the roof cap into engagement with the mine roof and retract such props and in turn the roof cap from engagement with the mine roof. Understandably, an appropriate second frame (not shown) is used with frame 40, such frames being interconnected by a suitable motive means, such as a piston cylinder arrangement of the type utilized in the construction of FIG. 2, whereby the resulting prop frame unit may be advanced in the desired way. Associated with frame 40 is a control block 45 which may be manually operated by the handle 49 and which may be operated automatically in accordance with the present invention, in this case by remote control. For this purpose control block 45 is operatively connected with a servomotor of the conventional type within servo-motor housing 46, the control block and timer device being controlled by the pulse signal receiving wireless device or transistor receiver 47 having the antenna 48, such receiver 47 operating in dependence upon signals received from a pulse signal transmitting wireless device 50 remote from the prop frame unit as seen in FIG. 5. Transmitting device 50 contains an actuating button 51 to send the signal via the antenna 53, with appropriate dials 52 being provided to select a predetermined frequency for governing a particular receiver 47 tuned to such particular frequency. The construction of the wireless transmitter 50 and receiver 47 is conventional and is therefore not shown in great detail since these elements are used as old elements in a new combination with a mining prop unit arrangement for the automatic advancement thereof in a time cycle. Upon receiving a signal from the trans mitting device 50, receiver 47 energizes an electromagnet 54. Thus, the armature 55 pivoted about point 56 is displaced to cause in turn the balance wheel brake 57 to disengage the adjacent balance wheel, so that fork 58 at the free end of such balance whee-l can urge against teeth 59 of the timing mechanism wheel 60 disposed on the shaft 61 to cause rotation of such shaft. Shaft 61 contains a small gear wheel 62 which operatively engages the large gear wheel 63 on shaft 64. This causes the rotation of roller 65 disposed on shaft 64 such that projections 66, 67, 68 and 69, or other cam means, will engage operatively the rocker levers 70, 71, 72 and 73, respectively, mounted on rod 74, or other follower means, whereby to cause the pistons 75, 76, 77, and 78, respectively, to be displaced within low pressure valves 79, 80, 81 and 82 operatively connected via flow lines 83, 84, 85 and 86 with the servo-motor (not shown) within housing 46. In response to pressure actuation via a given flow line, the servo-motor in turn causes corresponding movement of member 87 which appropriately controls the flow of pressure fluid, entering control block 45 through conduit 88, into the appropriate branch ' lines 90, 91, 92 and 93 for effecting prop unit advancement. The movement of member 87 also governs the return flow, respectively, from lines 90, 91, 92 and 93 through control block 45 and out via conduit 89. Conduits 88 and 89 may be connected in the conventional way with a pressure fluid reservoir. The pressure fluid in this instance as well as that contemplated in the operation of the units shown in FIG. 2 may be hydraulic or pneumatic, both such systems being contemplated by the terminology used in the instant specification and accompanying claims.

The transmitter 50 may be portable in nature, and thus carried by the particular operator at a safe distance from the prop frame unit being controlled to advance the same. Transmitter 50 will thus be battery powered and may be cheap, light, and simple in construction. The same is true for receiver 47, since its purpose is only to energize a small electromagnet 54 upon receiving a signal from transmitter 50. The electromagnetic force is extremely small since this merely controls brake 57 for the timing mechanism, run by a spring such as a clockwork spring (not shown), operatively connected to shaft 64, whereby to rotate roller 65 and in turn cause actuation of the valve means. Alternately, if an electric motor (not shown) is used to rotate shaft 64, a switch (not shown) similar in operation to brake 57 may be used for controlling such motor, the motor being ener gized by the same different battery or other power source used for receiver 47 and/ or electromagnet 54.

Projections 66 to 69 are positioned to attain a predetermined sequence of valve control for predetermined intervals, appropriately with the complete cycle of advancement of the particular prop unit corresponding with a complete rotation (360) of roller 65. Roller 65 may contain a preactive portion to achieve a preactive condition after brake S7 is released and prior to engagement of the first projection with the appropriate rocker lever to initiate the cycle of ordinal sequence of steps for advancing a given prop frame unit. Thus, if perchance a workman is too near the particular prop frame unit being advanced, there will still be time for such workman to remove himself without danger.

An audible or visual signal may even be provided near the particular prop frame unit being advanced, not only in connection with the embodiment of FIGS. 4 and S but also that of FIGS. 1, 2 and/ or 3, so that during any preactive interval, any workman nearby can be alerted to the automatic cycle which has been initiated to prevent mishap.

Thus, in accordance with the present invention, the timer device including a control block may be switched from inactive to active position automatically from a remote point or manually by a workman at the immediate site of the unit being advanced, with an appropriate time delay or preactive period during which such operator can remove himself, such that the advancement may take place automatically and in proper sequence. Thus the individual steps or movements of the props with respect to the mine roof and with respect to one another may take place in a cycle allocating a predetermined, yet adjustable, period of time for the completion of such individual movement or step, to attain a more efiicient advance of prop frame units than has been possible with previous constructions, whether completely automatic, remote or manual in nature.

The operator is left with sufiicient time to devote to other duties, since upon actuating the switch lever at the control block for a particular prop frame unit, the automatic cycle for accomplishing the prop frame unit advance takes place, whereupon the operator can get set for the actuation of the next timer device. Furthermore, due to the preferred preactive delay period, the operator may remove himself from the immediate site of the prop frame unit, and preferably the timer device and control block for one particular prop frame unit may be situated on the next adjacent prop frame unit, so that upon initiation of the automatic cycle of advancement, the operator is already removed from the danger area. In no case is it necessary for the operator to remain in the immediate vicinity of the advancing prop frame unit, as

in the past, for attending to the individual control steps to retract the first frame, advance such frame, extend such frame, retract the second frame, advance such second frame and extend such second frame. Instead, due to the automatic performance of the control procedure in accordance with the combination of the present invention, the operator may turn his attention to the next prop unit to be advanced or other matters.

Advantageously, it is advisable to provide along side the control block and/or timer device of the present invention whether remotely operated by Wireless means or not, a manually actuated control device of the conventional type. This will permit not only emergency manual actuation of a particular prop frame unit but also an attentive manually activated correction control. In the latter instance, in the event of mishap, or in the event that one step in the cycle is not completed for some reason before the next step in the time cycle must take place, upon inspection, the operator may correct the situation by manually actuating the valve means to accomplish the incomplete advance or even to change the longitudinal position of the prop frame unit or to adjust the position thereof to attain a more secure support of the mine roof, i. e., depending upon the particular conditions met. Since a manual correction control is possible, the timer device of the present invention can be constructed more simply and more cheaply than otherwise. The timer device understandably need only be capable of performing properly during the normal automatic control cycle but not for more precise correction control which is necessary in practice as where there is an irregular development of the miner-a1, such as coal or rock, which requires more specific attention than is inherently impossible to achieve with automatic cycle advancement.

While it is known to control an advanceable prop support unit of the instant type from a central point, as for instance from the discharge end of the conveyor, remote from the actual mine extraction site, this necessarily presupposes the provision for a large number of control lines which are constantly endangered by the vigorous operations indigenous to mining. Completely safe arrangements for the control lines are not possible to attain. Moreover, since the prop frame units are at a great distance from the control point, they cannot be checked to assure that they are operating properly unless a surveillance device is provided to indicate the proper completion of a previous controlled advancing step, whether retraction or extension of a particular prop frame or advancement of a particular prop frame. Indeed, the use of surveillance devices of such type is extremely costly and burdens the economy of the over-all operation.

-In accordance with the present invention, the central control from a remote distance is attained not by the use of control lines which may be damaged during the mining operations, but rather by wireless transmitting and receiving equipment. As will be appreciated by the artisan, such wireless equipment is effective whether the distance of the transmitting equipment is near or far from the receiving equipment. Indeed, relatively short distances within the mineway, such as two or three hundred meters in length, are easy and inexpensive to accommodate with existing transmitting devices since the transmitter need only be very small to govern the operation at such a distance. A portable transmitter may include its own current in the form of a battery and be conveniently carried by the operator, even where it is encapsulated for protection from fire-damp. The operator thus may control a conventional frame unit from the direct vicinity thereof or else from a great distance away in order to bring about the advancement of the unit, and also a number of frame units in a group may be similarly actuated for advancement simultaneously or successively. Where a remote control wireless transmitter and receiver are used, various receivers on selected frame units may 'be assigned different frequencies while others are assigned the same frequencies, so that simultaneous and/or successive actuation of the timer devices of such units may be attained in any given ordinal sequence in dependence upon the frequency selected for the transmitter and the receiving frequency of a particular receiver.

In connection with the embodiments of FIGS. 1 and 2, on the one hand and FIGS. 4 and 5 on the other hand, and even in connection with that of FIG. 3, the control block which may be utilized with the timer device may contain a servo-motor, controlled by the time switch and utilized for imparting power pulses to control the valve means and in turn the hydraulic pressure fluid flow necessary for the individual movements or steps to attain a complete cycle of advancement. Where a wireless transmitter and receiver are employed rather than other switch ing means for attaining the active condition of the timer device, such as by manual control, the servo-motor and time switch or control block mechanism may be utilized as the important units for controlling the valve means and such elements may be individually replaceable for versatility in operation with a minimum of interruptions. The timer device need only be small and primitive in construction provided the same is sufliciently dependable in operation, considering that the same need not itself directly actuate the control members or control valves for controlling the flow of hydraulic or pneumatic pressure fluid, since this may be accomplished by servo-motors of the conventional type and the like.

Preferably a given control block, timer device containing a servo-motor and the like should be assigned to each prop frame unit or to a plurality of prop frame units to be actuated simultaneously as a group. Also, as aforesaid, each unit should be provided with its own manual switching control to accomplish minor adjustments or corrections in the positioning of the particular prop frame unit.

Utilizing the arrangements in FIG. 2 and 3, regardless of whether the initiation of the timer device is attained manually or by remote control transmitting and receiving wireless means, sequential on simultaneous actuation of a plurality of prop frame units is attainable whereby the advancement of the entire array of mine face prop frame units can be accomplished within a period of time which is approximately equal to or only insignificantly longer than the time heretofore necessary for advancing a markedly smaller number of prop frame units. The conventional advancement by manual switching of a prop frame unit may take about 1 /2 minutes and in comparison utilizing the simultaneous operative interconnection of a number of timer devices in accordance with the present invention, ten successive groups of prop frame units may be advanced which may make up the units disposed along the entire length of the mine face. Thus, if ten units make up a given group, one hundred units may be advanced in only minutes in accordance with the automatic cycle advancement of the present invention, whereas 150 minutes would be normally required for individual manual actuation of such units.

Various arrangements for achieving the foregoing may occur to the artisan, such as by the connection of the control means, using cable means of the type contemplated in FIGS. 2 and 3 herein for instance, first to actuate a given prop frame unit, next to actuate the unit on one or the other side adjacent thereto or both units adjacent thereto, and so on. Suitably, one or several prop frame units may even be omitted from automatic control or selectively passed over as for example, where it is advisable to retain an original support of the mine roof in the immediate vicinity of a fault or at the end of the mine face area being worked.

In the case where a clockwork is used in the timer device of the invention, the same may be automatically returned to its starting position by rewinding a coil spring which may energize the same, or otherwise, this being accomplished at the end of the cycle, not only automatically but manually, by suitable means which will occur to the artisan. A brake or other releasable locking means is preferably associated with the timer device of the invention which may be released manually, via an electromagnet in response to a pulse or signal emitted from the transmitter as in FIGS. 4 and 5, or released by mechanical linkage means as in the case of the embodiment of FIGS. 1 and 2.

Understandably the nature and construction of the timer device of the present invention may take any form whatsoever although a convenient form is a spring operated short-time clockwork, possibly one having an idle initial movement or preactive condition before the active condition during which the cyclic automatic control in sequence of the valve means occurs to accomplish the advancement of a given prop frame uint or units.

A further embodiment of the time switch which may be utilized herein is a conventional laminated switch impeded, under constant dependence upon time, by the force of adherence of a flowing mass, in particular, a viscous mass such as dimethylpolysiloxane. The switch is provided with a manually actuated switch lever arranged concentrically in the particular control block and which is placed under the action of a spring force and also connected via a free wheel with a brake for the timer device in such a manner that the lever or a pin thereon under impedence of the flowing mass controls the valve means for achieving the advancement of the unit. A corresponding transmission means connected with such lever may achieve such control or a servo-control in the form of a servo-motor may be used which in turn controls operatively the valves to permit hydraulic fluid flow to and from the operative cylinders to achieve the retraction and extension of the prop and the longitudinal displacement of the motive means parts, such as a piston and a cylinder, with respect to one another. Because of the rotation of the switch lever, which is actually mounted on a rotatably positioned shaft in operative friction contact with the flowing mass, a more uniform and easier selection of individual switch functions is made possible, as compared with the use of an intermediate hydraulic linkage for actuating the particularly switching functions for the valve means. The retarding action of the flowable mass may also be utilized to achieve a preactive delay condition in a convenient way prior to the active condition of control of the lever with respect to the valve means in question. Such laminated switch may be termed a flowing mass switch or hydraulic delay member.

Understandably, in order to protect the roof from unwanted cave in, it is advisable to advance immediately adjacent prop frame units, or at least immediately adjacent frames of successive units, one after the other in time, rather than simultaneously, in order to avoid having too large a temporarily exposed roof area without any support.

If a hydraulic delay member or flowing mass switch of the aforementioned type is used as timer device according to the invention, the advancement to zero position from the terminal position for initiating the pre-active and thereafter the active condition may take place automatically with suitable locking means preventing a repeat cycle. If a spring drive is used, the spring when run down may be recocked, e.g. by turning the lever in the same way as the sweep hand of FIG. 1 is turned to do this. The lever is thus brought back to its initial position, and the timer device is ready for renewed actuation upon release of the locking means therefor.

All in all, the technical means for achieving the timer device control of the present invention for automatic sequence cycle performance of the various advancement steps are well known, and with little effort the artisan can arrange particular constructions to achieve the objects of the present invention. This may be undertaken at a relatively slight expenditure since the timing mechanisms intended need not be precise and accurate but only roughly so, keeping in mind that the individual operator may supplement the automatic advancement with corrective actuations by manual control without danger once the over-all automatic advancement in the manner of the invention has taken place. While it is conventional to use electric, hydraulic and pneumatic control systems for achieving switching performances, even by remote control, according to the invention such control systems, even remote control systems, may be used in a particular manner whereby only one or a few operators are needed to start the automatic advancement cycle. This is especially true where a number of prop frame units are interconnected for successive or simultaneous actuation and/or where portable transmitters are used by a few operators to advance a given prop frame unit or a group of prop frame units interconnected for simultaneous movement, merely upon the particular operators setting a predetermined frequency on a portable transmitter attuned to the receiving frequency of a wireless receiver utilized to start the automatic advancement cycle of one or more prop frame units.

A particular advantage of the present invention is in utilizing remote control means which avoid the use of any wires which might be damaged during normal mining operations, thus reducing expenses which might be otherwise necessary. The large number of control lines previously required to attain automatic advancement of prop frame units is avoided and in fact the manufacturing costs for attaining the automatic cycle control amount to about /2 to of the costs needed heretofore.

The individual steps for retracting, advancing and extending of the prop frames are carried out in short intervals and if for some reason One of the steps does not take place properly during the interval assigned for its execution, the next step will occur, and in all instances a retracted frame will in the next subsequent step again be extended by the timer device control to ensure proper support of the mine roof. To this extent there is greater dependability in utilizing the instant construction combination than was obtainable with the known arrangements, such as those in which a particular frame could only be extended into engagement with the mine roof after such frame had completed its full advancing step in the desired direction of advance.

It cannot be over-stressed that the wireless receiver contemplated herein as well as the timer device and/ or servomotor which may be used consume practically no power. The comparatively slight amount of energy necessary for operating the receiver, timer device, servo-motor, etc., can be readily obtained from a simple electric battery for long periods of time before recharging of the battery is necessary. Considering that the timing mechanism utilized does not need much power for controlling the pulses or other mechanical or electrical responses which it must provide in order to set the working of the particular valve means, the same will also be able to utilize the power source of the receiver. The timer device actually will only control a servo-control, e.g., a servo-motor and linkages, or some similar interposed device which acts in turn to control the flow of hydraulic or pneumatic fluid through the valve means to accomplish the advancing steps.

In particular, the timer device, wireless receiver, servocontrol, e.g., servo-motor, and the like, are preferably independent structural units which can be combined in the foriri of the control block, such as that shown in FIGS. 4 and 5, in the preferred embodiment together with a manual control for the valve means so that versatility in operations may be attained as well as individual replacement of any of the parts which wear out or become defective for any reason. By providing the various coacting elements in a single device, i.e., a control block, such control block may be positioned as a compact member on a given prop frame whereby to control the advancement of that frame unit or the next adjacent frame unit, or for that matter a group of frame units simultaneously, in the even such frame units are cooperatively interconnected to accomplish this result, as the artisan will appreciate.

In view of the various advantages attainable by the versatile use of the instant combination of elements, in mining operations there will be less danger to the miner than can be said for present day prop frame control devices whether mechanical, automatic and/ or remote.

An important problem which occurs in mining operations utilizing remote control wireless transmitters and receivers relates to decline in efiiciency in transmitting pulses or signals because of the large amount of iron in the form of structural elements in the mineway being worked. Under such conditions, even where a portable wireless transmitter is used, a certain amount of the transmission energy is screened off and accordingly a given group or groups of prop frame units may not be influenced by the transmission energy through the corresponding wireless receivers situated therewith. To avoid this possibility and to ensure that all of the prop frame units intended to be controlled do execute the advancement desired, it is possible in accordance with the present invention, as the artisan will appreciate, to lay an antenna along the extent of the mine face and connect with it the individual receivers which are far distant from the transmitter so that only the section of the antenna nearest to the particular transmitter station and within range need be controlled by the transmitter through its attendant signals. This antenna serves to extend the range of the portable wireless transmitter since it need only influence the portion of the antenna nearest to it, whereas the antenna will carry over the comparatively long strip of the mineway the transmission energy so that the particular receiver intended to be actuated will be in fact so actuated. Of course, the transmission energy can also be stored directly in a conductor at various points along the mineway by attachment to lines which may be disposed therealong for this purpose.

In relatively complicated mining operations, the individual prop frame units can be controlled to achieve the step by step advance by the utilization of a cable means, such as that of FIGS. 2 and 3. Preferably, means are provided to ensure that the controlled cycle of a prior timer device, in accordance with the present invention, must be complete before the next successive controlled cycle can be initiated to advance the next successive prop frame unit. Suitable time control devices and/or devices which release locking means upon the prior timer device reaching its end position, analogous to the arrangement shown in FIGS. 1 and 2, for instance, may be used to ensure that a given prop unit is not advanced prior to the desired time and to ensure an orderly sequence of advancement in a predetermined manner. Coupled with the foregoing may be delay action or delay period conditions between the end of one controlled cycle for one prop unit and the start of the next controlled cycle for the next successive prop unit, whereby to ensure the safety of the miners who may be in the vicinity of the prop units being advanced.

Where an arrangement such as that shown in FIG. 3 is utilized, the extent of axial displacement or longitudinal displacement of the cable will determine whether the respective prop units are being or have been advanced in the desired way. Thus, if a particular unit is not advanced, by indicia markings along the control cable the place of blockage of the cable can be readily ascertained and concomitantly the particular prop frame unit which has failed to complete the advancement cycle and which has thus prevented release of the locking means for initiating the advancement cycle of the next unit. Such indications will make immediately aware to the operating personnel that a given unit has not properly carried out the step by step advancement operation and may not be in effective supporting engagement with the mine roof. The defect may be easily ascertained, despite the fact that poor visibility or complicated operations would otherwise render the ascertainment of defects in the automatic advancement operation difiicult, especially in areas remote from the point of observation. Obviously, the use of a marked cable for this purpose is simple in construction and operation and extremely inexpensive to provide.

Indeed, the use of marked cables may be of importance where the first, eleventh, twenty-first, etc. prop units are to be simultaneously advanced, and the second, twelfth, twenty-second, etc. are to be next advanced, and so on, since, for example, out of a possible 100 prop units being controlled, such units simultaneously by each cable, the effective operation of a particular unit may be ascertained by the lack of further movement of the control cable caused by the aforesaid locking means so that the number of possibilities is narrowed immediately to 10, and thence by visual inspection or other means to the single unit which is defective in operation. The particular cable may be rewound after the full displacement thereof for attaining the control of the advancement of all of the units in question. However, where a particular locking means has not been released and the cable cannot complete its full displacement, a simple procedure is to rewind the cable and merely check by visual inspection before further advancement. Any simple mechanism can also be utilized to determine remotely which prop unit is defective in its advancement so that it is unecessary to rewind the cable to its starting position and attempt visual inspection, but of course the use of a cable arrangement such as that in FIGS. 2 and 3 herein will avoid the extremely complicated return signal devices usually provided in electrical control devices presently employed in advancing prop units. As aforesaid, a combination of elements has not been employed before to attain a timed cycle control of the six advancement steps enumerated hereinabove, with the next step being carried out after a given time interval regardless of whether the previous advancement step has been completed or not, whereupon the delays caused in the past are not encountered, such delays in particular relating to the breakdown of the cycle where a particular step such as a retractor, extension, or motive means actuation cannot execute its full amplitude of operation. In accordance with the present invention, it is thus now possible to obtain partial automation of advancement of prop frame units with relatively cheap structural elements arranged in the novel combination disclosed herein. In particular, it will be appreciated that a fundamental change in the structure of the prop frame units is unnecessary and rather the combination of the invention may be attained even where the prop unit contains manual switch controls. Expeditiously, the automatic sequence valve control means, e.g., timer device, etc., of the present invention may be provided as an additional compact control device on a preexisting prop frame unit already containing a manual switching control device to accomplish versatility in operation for advancement automatically and for controlling minor adjustments manually with a minimum of danger to the operating personnel.

It will be appreciated that the automatic sequence valve control device of the present invention may be utilized on any given type of prop support mechanism, including one containing a pair of prop frames interconnected by a piston-cylinder arrangement such as that shown in aforesaid U.S. Patent 3,192,722, as well as the prop frame unit arrangements of the other aforementioned U.S. patents, and even on the prop frame units disclosed in any and all of the prior art cited in the applications leading to all of the aforementioned patents. The important feature is that a pair of prop means is connected for alternate advancement in a given longitudinal or linear direction and such advancement is normally carried out with a motive means having a first motive part connected with one prop means and another motive part connected with a second prop means, especially by way of a piston-cylinder arrangement with the piston connected to one prop means and cylinder connected to the other prop means. As used herein, the term prop means does not merely signify a pair of props having a base and a roof cap whereby to form a prop frame, but may signify a single extensible prop, such as one using the hydraulic jack principle, connected to each motive part, so that the one prop will move with the cylinder and the other prop will move with the piston. Also, a pair of such props may be utilized not in the form of the usual prop frame, of the type shown in FIG. 2 or 4, but rather with such props being connected for common displacement with the piston or the cylinder of the motive device, such as by connection with such piston or cylinder through a base means or a roof cap or through direct connection of each prop separately from the other with the cylinder itself or the piston itself. Of course, a multiplicity of props may be carried in a frame or through an intermediate connection or directly with the cylinder itself or the piston itself to accomplish the roof support contemplated as well as the advancement steps in an automatic manner in accordance with the invention. Indeed, arrangements are known for connecting a plurality of prop means as intended by the foregoing language for independent relative movement of one such prop means with respect to the remaining prop means by suitable hydraulic actuation of motive means designed to accomplish more than two actuations so as to advance more than two prop means, such as three prop means. Thus, a piston-cylinder arrangement may include a normal cylinder as well as a normal piston in the form of a hollow piston rod within which a further piston rod is disposed such that the hollow piston rod forms an internal cylinder for such further piston rod. In this way, by suitable hydraulic or pneumatic fluid flow, first the further piston and a first prop means connected therewith may be advanced with respect to the remainder of the device, then the normal piston forming the cylinder for such further piston may be advanced with a second prop means connected therewith, and then the normal cylinder with a third prop means connected therewith may be advanced, as the artisan will appreciate. Suitable fluid flow conduit arrangements may be utilized to advance any one of the three motive elements and the corresponding prop means connected therewith without also displacing either of the other two motive elements with their respective prop means, or may be utilized to attain movement of any two of the prop means with respect to the remaining one of the prop means. As will occur to the artisan, the multiple number of individual prop means advanceable with respect to the remaining prop means is a matter of expediency and in any of these situations the automatic sequence valve control means of the present invention may be adapted to program a given cycle of prearranged ordinal sequence of control of appropriate valve means to attain the desired results.

To attain the advantages of the present invention, a wireless transmitter and receiver may be used of the type found in factories, ofiices, etc., by which a roving person is paged. This is carried out by transmitting a signal or pulse from the transmitter device to a roving person in the area who carries a small frequency receiver on him which emits a buzzing sound or signal when being called. Such small receivers are capable of response over a sufiicient range, are light, relatively cheap, and simple in construction. The sole function of such receiver is to control an electromagnet which actuates the buzzer or other signal. A simple battery of the dry cell type may be used in the receiver for the actuation and for powering the receiver itself. In connection with the timer device of the present invention, for example that shown in FIGS. 4 and 5, the small electromagnet is used in the same way, upon a signal being received by the receiver, whereby to start the mechanism of a clockwork or some other mechanism which initiates the automatic cycle for achieving control of the advancement steps. Of course, the electromagnet may actuate a brake to start and stop the timer, either through the starting and stopping of an electric switch where the timer is electrically operated or to start the release of a coil spring where the clockwork or analogous mechanism is spring operated. In the one case the timer power is via a manually cocked spring and in the other case the power to drive the electric clock mechanism may be obtained from the same battery used to operate the receiver and the electric magnet. Timers of the type contemplated herein are very simple, mass-produced items, such as the clock mechanism in a wind-up alarm clock or a wind-up timer of short duration (e.g., one to five minutes), or in a simple electrically operated kitchen clock. The cost factor of such a mechanism is indeed slight. The simplicity in construction of a timer, receiver, servo-control, or the like, for operating the valve means for the advancement steps, lends itself to the use of these elements in a very compact single package, such as a control block, permitting easy replacement of the parts and ready substitution of one package for another on a given prop unit. Of course, the preferred embodiment contemplates the use of wireless remote transmission and receiving means, although a mechanical cable actuation, such as that shown in FIG. 2 or FIG. 3, is indeed possible for actuating responsive levers and the like to achieve the initiation of the controlled cycle advance. Once a particular timer is initiated, by remote control means, cable means, manually, or otherwise, in accordance with the present invention, the individual six steps will take place in predetermined ordinal sequence and for predetermined time intervals adjusted to permit a normal completion of a particular step before the next step will automatically take place. The receivers, of course, should be protected against fire-damp, although this will not unduly increase the size of the package in question, and the timers need not be extremely accurate since the main feature is in attaining the steps for the advancement in general, whereupon manual switching adjustments may be utilized to correct any incomplete step caused by slight inaccuracies in time intervals permitted. The relatively primitive means of the entire mechanism for achieving the remote control advancement of the entire prop units, with elements which may be readily replaceable and be able to fit into a small space, represents an essential advantage over the prior art.

Moreover, the coupling of the individual timer devices, such as in the arrangements of FIGS. 2 and 3, may be achieved by electrical means, as the artisan may readily appreciate, even simpler in constructional arrangement than the mechanical means shown. However, it is not absolutely necessary that more than one prop unit be coupled with others for joint advancement. An alternative form of advancement is to connect a number of receivers to the same antenna laid along the mine face so that the transmitted signal may be received simultaneously at all of the receivers connected to such antenna to attain the simultaneous advancement of the respective prop units associated therewith. A more versatile control, of course, will be achieved by adjusting the frequencies of the transmitters to the frequencies of the receivers to be controlled. Hence, a particular transmitter used to control a specific prop unit or group of prop units may be adjusted to the predetermined frequency to which the receiver or receivers for such specific prop unit or group of prop units has been previously set.

What is claimed is:

1. An advanceable mining prop arrangement with hydraulically actuatable motive means, motive valve means controlling such motive means, each prop being hydraulically actuatable to change the effective length thereof for alternate extension into and retraction from supporting engagement with the mine roof and mine floor upon hydraulic actuation, in combination with automatic sequence valve control means operatively connected with said motive valve means, said sequence valve control means being separately positioned at a remote distance from such prop unit sufficiently to permit switching of said sequence valve control means without danger to the operator from the resultant changes in condition of said prop unit and the mine roof area being supported thereby, said control means so combined with timing means as to operate them in an automatic timed cycle operation.

2. Arrangement according to claim 1 wherein supplemental manual switch means are provided in operative association, separately from said sequence valve control means.

3. An advanceable mining prop arrangement with hydraulically actuatable motive means, motive valve means controlling such motive means, each prop being hydraulically actuatable to change the effective length thereof for alternate extension into and retraction from supporting engagement with the mine roof and mine floor upon hydraulic actuation, in combination with automatic sequence valve control means operatively connected with said motive valve means, said control means so combined with timing means as to operate them in an automatic timed cycle operation, said timing means including an automatic timer device which when switched from inactive to active condition passes through a timed cycle to control the actuation in turn of said valve means in the required sequence.

4. Arrangement according to claim 3 wherein said timer device includes a preactive condition of preset duration upon being switched from said inactive condition and prior to attaining said active condition as a safety delay period to permit the operator time to leave the immediate prop unit site before the resultant changes in condition of said prop unit and the mine roof area being supported thereby occur upon said timer device attaining said active condition.

5. Arrangement according to claim 4 wherein said timer device includes a control block provided with a dial face having an active portion containing valve means switch contacts ordinally positioned thereon operatively connected with said valve means to control the corresponding hydraulic flow therethrough, and a sweep hand switch contact which upon being switched from said inactive condition is movable from a starting position initially through a preactive portion of said dial for attaining said preactive condition of preset duration and then through said active portion of said dial in contact for predetermined intervals in time-controlled sequence ordinally with said contacts to actuate said valve means, whereupon said sweep hand switch contact reaches a terminal position of inactive spent condition.

6. Arrangement according to claim 5 wherein releasable locking means are provided at said starting position to control the switching of said sweep hand switch contact from inactive to preactive and active conditions.

7. Arrangement according to claim 6 wherein a plurality of said advanceable prop units, each in combination with a respective automatic timer device, is provided in succession in operative adjacency, the control blocks of such timer devices being operatively connected for successive operation via cable means actuatable to control the respective releasable locking means for release in succession to permit the separate ordinal sequence actuation of the said valve means for advancing each prop unit respectively in succession.

8. Arrangement according to claim 7 wherein said cable means includes a displaceable cable which is provided with a lug thereon positioned for travel along a path into which said releasable locking means are situated in succession such that upon actuation to displace said cable said lug trips said locking means in succession to release the respective sweep hand switch contacts for carrying out the advancing of each prop unit respectively in succession.

9. Arrangement according to claim 7 wherein said cable means include separate axially displaceable and thrust sub-cables, each sub-cable respectively operatively interconnecting the control block of the timing device of a prior prop unit with that of the next prop unit in succession, one end of each such sub-cable being operatively situated at the terminal position of the control block of the timing device of a respective prior prop unit and in the path of the corresponding sweep hand switch contact thereof and the other end of such sub-cable being operatively connected with the locking means of the control block of the timing device of the next prop unit in succession for release of such locking means upon axial displacement of such sub-cable, such that upon switching the control block of the timer device of the first prop unit in succession from inactive to active condition for advancing said first prop unit and in turn upon the sweep hand switch contact thereof reaching the corresponding terminal position, such sweep hand switch contact will strike said one end of the corresponding sub-cable between the first prop unit and the next prop unit in succession to cause axial displacement of such corresponding sub-cable and in turn cause said other end of such corresponding sub-cable to release the locking means of the control block of the timer device of the next prop unit in succession for advancing said next prop unit, and in turn in the same way each of the subsequent locking means in succession by the appropriate sub-cable for advancing each of the further prop units one after the next until the last prop unit in succession has been advanced and the corresponding sweep hand switch contact thereof has reached the corresponding terminal position.

10. Arrangement according to claim 3 wherein said automatic timer device includes a drive linkage operatively connected with displaceable cam means, and cam actuatable response means operatively connected with said valve means to control the corresponding hydraulic flow therethrough, said drive linkage, upon switching said timing device from inactive to active position, being energizable to displace said cam means, and wherein said response means includes follower means positioned in the path of displacement of said cam means for actuation thereby to control said valve means.

11. Arrangement according to claim wherein said drive linkage includes rotatable gear means, said cam means include a rotatable shaft, having a plurality of cams thereon of predetermined disposition, which is operatively connected with said drive linkage via said gear means for rotation thereby, said follower means being positioned in the path of said cams for appropriate actuation thereby for predetermined intervals in time controlled sequence in dependence upon the predetermined disposition of said cams, and said response means includes a servo-motor operatively connected with said follower means to control said valve means in response to the actuation of said follower means by said cams, and wherein brake means are provided for switching said drive linkage from inactive to active condition, such that upon being switched to active condition, said drive means is able to rotate said shaft via said gear means and actuate said servo-motor via said follower means for predetermined intervals in time controlled sequence ordinally.

12. Arrangement according to claim 11 wherein remote control means are operatively connected with said brake means to actuate said brake means for switching said drive linkage from inactive to active condition and in turn from active to inactive condition.

13. Arrangement according to claim 12 wherein said remote control means include a pulse signal transmitting wireless device remote from such mining prop arrangement and a pulse signal receiving wireless device operatively connected with said brake means for actuating said brake means in dependence upon the pulses received.

14. An advanceable mining prop arrangement which comprises an advanceable mining prop unit including first means having at least one prop and second means apart from said first means and prop and operatively inter connected with said first means and prop for alternate advancement therewith via hydraulically actuatable motive means, motive valve means controlling the actuation of such motive means, said prop being hydraulically actuatable to change the effective length thereof for alternate extension into and retraction from supporting engagement with the mine roof and mine floor upon hydraulic actuation, and prop valve means, in combination with automatic sequence valve control means operatively connected with said motive valve means and prop valve means for regulating the corresponding hydraulic flow therethrough in predetermined ordinal sequence and for predetermined intervals in an automatic cycle operation, said sequence valve control means being separately positioned at a remote distance from such prop unit sufficiently to permit switching of said sequence valve control means without danger to the operator from the resultant changes in condition of said prop unit and the mine roof area being supported thereby.

15. Arrangement according to claim 14 wherein supplemental manual switch means are provided in operative association, separately from said sequence valve control means, with said motive valve means and said prop valve means.

16. Arrangement according to claim 14 wherein said sequence valve control means include an automatic timer device which when switched from inactive to active condition passes through a timed cycle to control the actuation in turn of said valve means in the required sequence.

17. An advanceable mining prop arrangement which comprises an advanceable prop unit including hydraulically actuatable motive means having a first motive part and a second motive part operatively interconnected for back and forth alternate longitudinal displacement with respect to each other upon corresponding alternate hydraulic actuation, motive valve means controlling such alternate hydraulic actuation, prop means including a first prop connected to said first motive part for longitudinal displacement therewith and a second prop connected to said second motive part for longitudinal displacement therewith, each said prop being hydraulically actuatable independently of the other to change the ef fective length thereof for alternate extension into and retraction from supporting engagement with the mine roof and mine floor upon corresponding alternate hydraulic actuation, and first prop valve means for said first prop and second prop valve means for said second prop correspondingly controlling such alternate hydraulic actuation, in combination with automatic sequence valve control means operatively connected with said motive valve means, first prop valve means and second prop valve means to actuate said valve means for regulating the corresponding hydraulic flow therethrough in predetermined ordinal sequence and for predetermined intervals in an automatic cycle operation, said sequence valve control means being switchable from an inactive condition to an active condition wherein, when both said props are extended into engagement with the mine roof, said sequence valve control means in sequence automatically firstly actuates said first prop valve means for retraction of said first prop from engagement with the mine roof, secondly actuates said motive valve means for longitudinal displacement of said first motive part and said first prop with respect to said second motive part and said second prop in a given longitudinal direction of advance, thirdly actuates said first prop valve means for extension of said first prop into engagement with the mine roof, fourthly actuates said second prop valve means for retraction of said second prop from engagement with the mine roof, fifthly actuates said motive valve means for longitudinal displacement of said second motive part and said second prop with respect to said first motive part and said first prop in said direction of advance, and sixthly actuates said second prop valve means for extension of said second prop into engagement with the mine roof.

18. Arrangement according to claim 17 wherein supplemental manual switch means are provided in operamanual actuation of said valve means.

19. Arrangement according to claim 17 wherein said sequence valve control means are separately positioned at a remote distance from said prop unit suflieient to permit switching of said sequence valve control means without danger to the operator from the resultant changes in condition of said prop unit and the mine roof area being supported thereby.

20. Arrangement according to claim 17 wherein said sequence valve control means include an automatic timer device which when switched from inactive to active condition passes through a timed cycle to control the actuation in turn of said valve means in the required sequence.

21. Arrangement according to claim 20 wherein said timer device includes a preactive condition of present duration upon being switched from said inactive condition and prior to attaining said active condition as a safety delay period to permit the operator time to leave the immediate prop unit site before the resultant changes in condition of said prop unit and the mine roof area being supported thereby occur upon said timer device attaining said active condition.

22. Arrangement according to claim 21 wherein said timer device includes a control block provided with a dial face having an active portion containing six valve means switch contacts ordinally positioned thereon operatively connected with said valve means to control the corresponding hydraulic flow therethrough, and a loaded spring operated sweep hand switch contact which upon being switched from said inactive condition is movable under the operative force of said spring from a starting position initially through a preactive portion of said dial for attaining said preactive condition of preset duration and then through said active portion of said dial in contact for predetermined intervals in time controlled sequence ordinally with the first contact to actuate said first prop valve means for retraction of said first prop, with the second contact to actuate said motive valve means for displacement of said first motive part and first prop, with the third contact to actuate said first prop valve means for extension of said first prop, with the fourth contact to actuate said second prop valve means for retraction of said second prop, with the fifth contact to actuate said motive valve means for displacement of said second motive part and said second prop, and with the sixth contact to actuate said second prop valve means for extension of said second prop, whereupon said sweep hand switch contact reaches a terminal position of inactive spent condition.

23. Arrangement according to claim 22 wherein said control block is resettable to the original inactive condition by return movement of said sweep hand switch contact to reload said spring to said starting position.

24. Arrangement according to claim 23 wherein releasable locking means are provided at said starting position to control the switching of said sweep hand switch contact from inactive to preactive and active conditions.

25. Arrangement according to claim 24 wherein a plurality of said advanceable prop units, each in combination with a respective automatic timer device, is provided in succession in operative adjacency, the control blocks of such timer devices being operatively connected for successive operation via cable means actuatable to control the respective releasable locking means for release in succession to permit the separate ordinal sequence actuation of the said valve means for advancing each prop unit respectively in succession.

26. Arrangement according to claim 25 wherein said cable means includes a displaceable cable which is provided with a lug thereon positioned for travel along a path into which said releasable locking means are situated in succession such that upon actuation to displace said cable said lug trips said locking mean in succession to release the respective sweep hand switch contacts for carrying out the advancing of each prop unit respectively in succession.

27. Arrangement according to claim 25 wherein said cable means include separate axially displaceable and thrust sub-cables, each sub-cable respectively operatively interconnecting the control block of the timing device of a prior prop unit with that of the next prop unit in succession, one end of each such sub-cable being operatively situated at the terminal position of the control block of the timing device of a respective prior prop unit and in the path of the corresponding sweep hand switch contact thereof and the other end of such sub-cable being operatively connected with the locking means of the control block of the timing device of the next prop unit in succession for release of such locking means upon axial displacement of such sub-cable, such that upon switching the control block of the timer device of the first prop unit in succession from inactive to active condition for advancing said first prop unit and in turn upon the sweep hand switch contact thereof reaching the corresponding terminal position, such sweep hand switch contact will strike said one end of the corresponding sub-cable between the first prop unit and the next prop unit in succession to cause axial displacement of such corresponding sub-cable and in turn cause said other end of such corresponding sub-cable to release the locking means of the control block of the timer device of the next prop unit in succession for advancing said next prop unit, and in turn in the same way each of the subsequent locking means in succession by the appropriate sub-cable for advancing each of the further prop units one after the next until the last prop unit in succession has been advanced and the corresponding sweep hand switch contact thereof has reached the corresponding terminal position.

28. Arrangement according to claim 20 wherein said automatic timer device includes a drive linkage operatively connected with displaceable cam means, and cam actuatable response means operatively connected with said valve means to control the corresponding hydraulic flow therethrough, said drive linkage, upon switching said timing device from inactive to active position, being energizable to displace said cam means, and wherein said response means includes follower means positioned in the path of displacement of said cam means for actuation thereby to control said valve means.

29. Arrangement according to claim 28 wherein said drive linkage includes rotatable gear means, said cam means include a rotatable shaft, having a plurality of cams thereon of predetermined disposition, which is operatively connected with said drive linkage via said gear means for rotation thereby, said follower means being positioned in the path of said cams for appropriate actuation thereby for predetermined intervals in time controlled sequence in dependence upon the predetermined disposition of said cams, and said response means includes a servo-motor operatively connected with said follower means to control said valve means in response to the actuation of said follower means by said cams, and wherein brake means are provided for switching said drive linkage from inactive to active condition, such that upon being switched to active condition, said drive means is able to rotate said shaft via said gear means and actuate said servo-motor via said follower means for predetermined intervals in time controlled sequence ordinally, firstly to actuate correspondingly said first prop valve means for retraction of said first prop, secondly to actuate correspondingly said motive valve means for displacement of said first motive part and first prop, thirdly to actuate correspondingly said first prop valve means for extension of said first prop, fourthly to actuate correspondingly said second prop valve means for retraction of said second prop, fifthly to actuate correspondingly said motive valve means for displacement of said second motive part and said second prop, and sixthly to actuate correspondingly said second prop valve means for extension of said second prop.

30. Arrangement according to claim 29 wherein remote control means are operatively connected with said brake means to actuate said brake means for switching said drive linkage from inactive to active condition and in turn from active to inactive condition.

31. Arrangement according to claim 30 wherein said remote control means include a pulse signal transmitting wireless device remote from such mining prop arrangement and a pulse signal receiving wireless device operatively connected with said brake means for actuating said brake means in dependence upon the pulses received.

References Cited UNITED STATES PATENTS 3,207,041 9/1965 Phillips 91-1 3,285,015 11/1966 Carnegie et al 6145.2

EDGAR W. GEOGHEGAN, Primary Examiner.

U.S. Cl. X.R.

UNITED sTATEs PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,434,389 March 25 1969 Hans-Theodor Grisebach It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, line 4, after "Lunen, insert Westphalia,. Column 23, line 19, "present" should read preset Signed and sealed this 7th day of April 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer

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