US2579981A - Apparatus for effecting or controlling traverse of a body between opposed walls - Google Patents

Apparatus for effecting or controlling traverse of a body between opposed walls Download PDF

Info

Publication number
US2579981A
US2579981A US600379A US60037945A US2579981A US 2579981 A US2579981 A US 2579981A US 600379 A US600379 A US 600379A US 60037945 A US60037945 A US 60037945A US 2579981 A US2579981 A US 2579981A
Authority
US
United States
Prior art keywords
strut
carriage
walls
opposed walls
effecting
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US600379A
Inventor
Spragg Harry
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MARKHAM AND CO Ltd
Original Assignee
MARKHAM AND CO Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by MARKHAM AND CO Ltd filed Critical MARKHAM AND CO Ltd
Application granted granted Critical
Publication of US2579981A publication Critical patent/US2579981A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • EFIXED CONSTRUCTIONS
    • E21EARTH OR ROCK DRILLING; MINING
    • E21CMINING OR QUARRYING
    • E21C29/00Propulsion of machines for slitting or completely freeing the mineral from the seam
    • E21C29/02Propulsion of machines for slitting or completely freeing the mineral from the seam by means on the machine exerting a thrust against fixed supports

Definitions

  • a cordi to th s inventi an pparatus for traversing or controlling the traverse of a body along and between opposed walls, such as a roof and flo o a mine, compri a str t long r than the distance between the walls, a carriage -on which said strut is oscillatably mounted,
  • driving means are arranged to connect the aforesaid strut assemblage with sai body. wh ch me n e adapted to effect -relative reciprocatory movement between said as em lage and ody al n th line of traverse. 'It will be appreciated with this arrangement that when the driving means connecting the assemblage with the body effects relative movement during one stroke of reciprocation, the strut will be pivoted against the action of the loading means so as to release the assemblage from the that the oscillating movements of the struts may take place in any desired sequence, whereby the resultant movement of the body may approximate to uniform.
  • the aforesaid carriage may be provided with wheels ormay comprise a sledge adapted to engage one of the said walls, and pivotally carries said strut, one end of which engages the other wall.
  • the loading means aforesaid may comprise spring means or a hydraulically or pneumatically operated plunger connected between said strut and said carriage so as to apply a force tending to maintain the strut and the carriage in abut-
  • the means, for connecting the assemblage with the "body may either be secured to the carriage or may be pivotally connected'to the strut. This. arrangement is particularly suitable when the apparatus is arranged as a safety device for controlling the traverse of the body between the two walls, For example, assuming it is arranged for preventing machines or other objects hauled by ropes or chains from running away due to a breakdown of the haulage system when proceeding along a steep incline.
  • the strut assemblage is either arranged to be trailed behind or pushed in front of the machine or object by means of a connecting-rod, and the arrangement of the connection is such that during normal haulage the force imparted to'the strut through the connection tends to move it out of engagement with the wall, whereas, in the event of the failure of the haulage system, there will be a reversal of the force applied to the connecting-rod, tending to jam the strut against the wall and thereby prevent run-away.
  • a haulage member may be connected to the strut, so that under normal haulage conditions, it tends to pull the strut free of th walls,
  • the said driving means may comprise a crank or eccentric rotatably driven and mounted on one of the parts, and a connectingrod driven thereby and pivotally connected to the other part.
  • the rotatably driven crank or eccentric may be mounted on said body, and the associated connecting-rod is either pivotally connected to the carriage or to said strut.
  • means may be provided for adjusting the eifective length of the strut so that the apparatus may be used for different distances between the opposed walls.
  • Figure 1 is a sectional side elevation of the apparatus
  • Figure 2 is a plan view
  • Figure 3 is an end elevation of the strut.
  • the apparatus comprises two sledges arranged side-by-side at ID in Figure 1 and each having a flat bottom wall ll arranged to rest on the 'mine floor.
  • Each sledge is provided with uptilted ing arms l8 extending beyond the end of the strut so as to form a fork-piece I9. as best seen in Figure 3.
  • Each of the brackets is provided with a supporting block 20 which carries a fulcrum pin 2
  • a connecting-rod 22 has one end between the arms iii of the fork-piece l9 and is secured thereto by a pin 23 which passes through holes in said arms.
  • the pin is secured in position by means of a plate 24 secured to one of the arms and projecting into a groove formed in the end of the pin.
  • the extremities of the arms l8 are provided with slots 25 which embrace pins 26 projecting laterally from each side of a tubular shuttle member 21.
  • the shuttle member is reciprocably mounted on a rod 28 fixed between two projections 29 on the bottom of the sledge.
  • a compression spring 30 Disposed between each end of the shuttle and the nearest abutment is a compression spring 30, the two compression springs being so arranged as to bring the strut at right-angles to the bot tom wall of the sledge.
  • Adjustably secured to the upper end of each strut are two members 50 which are secured together at their upper extremities by a spacing block 3
  • the members 50 are so shaped and dimensioned as to lie flat against the web portion of the H-sectioned strut between the flanges thereof.
  • the web portion of the strut is provided with a number of holes 32 and a hole in each of the members 50 may be brought intoregister with one of the holes in the web portion.
  • the forked member may be retained in a required position on the strut by means of a bolt 33 which extends through the registering holes and is provided with a wing-nut 34 for clamping the assemblage in position.
  • the spacing block carries a pin 35 projecting on each side thereof and extending through holes in side members 35 formed on the underside of a shoe 31. As in the case of the sledge, the ends of the shoe are bent away from the main plane thereof, as shown at 38, so.
  • the two sledges are loosely coupled together by a number of inverted channel-shaped members 40 arranged to extend over upstanding parts 4
  • the connecting-rod 22 is connected to a driving element which may either be formed integral with the body which requires to be moved, or may be formed as a separate unit 50 mounted on a sledge as shown in the drawings, which unit 50 may in turn be connected to the body to be moved.
  • the driving means may comprise a compressed air motor 43 which drives an eccentric 44 through suitablegearing 45, compressed air being supplied through pipe 52.
  • the eccentric is encircled by a strap 46 having a connecting-rod 41 secured to a lever-arm 48 on a. double-throw crankshaft 49.
  • the crankshaft is provided with two crank-pins for connecting respectively to the two connecting-rods, which crank-pins are arranged apart on the crankshaft, so that the movement imparted to the body to be traversed approximates to uniform movement.
  • Apparatus for traversing a body along and between opposed walls, such as the roof and floor of a mine comprising two carriages separate from andunsupported by said body arranged to move along one wall, a strut longer than the distance between the walls pivotally mounted on each carriage at a distance away from the lower end thereof so that it is inclined to the vertical, spring means between the lower end of each strut and the carriage so as automatically to maintain the engagement of the carriage and the strut with said walls without imparting up and down thrust to the body, and a reciprocable member on said body pivotally connecting each strut and carriage assemblage to the body and to impart relative reciprocatory movement between each said carriage and the body in out-of-phase relationship.
  • Apparatus for traversing a body along and between opposed walls, such as the roof and floor or" a mine comprising two carriages arranged to move along one wall, a strut longer than the distance between the walls pivotally mounted on each carriage so that it is inclined to the vertical, resilient yielding means automatically maintaining the engagement of each carriage and strut with said walls, driving means on said body comprising a crank shaft having two crank pins disposed at 180, and connecting rods pivotally attached to the crank pins and to the lower extremities of said struts respectively whereby reciprocatory movement is imparted to the carriages in out of phase relationship.
  • Apparatus for traversing a body along and between opposed walls such as the roof and floor of a mine comprising two carriages disposed side by side to move along one wall, a strut associated with each carriage, a pivotal mounting on each carriage engaging a strut a short distance from its lower extremity, the length of each of which struts above its pivotal connection together with the distance of the pivotal connection from the bottom of the carriage is greater than the dis tance between the Walls so that each strut is inclinedto the vertical, resilient yielding means for automatically maintaining the engagement of each carriage and strut with said walls, driving means on said body comprising a crank shaft having two crank pins disposed at 180, and connecting rods pivotally attached to the crank pins and to those parts of the struts beneath their pivotal connections with the mounting whereby reciprocatory movement may be imparted to the two carriages in out of phase relationship.
  • Apparatus for traversing a body along and between opposed walls such as the roof and floor of the mine comprising two carriages disposed side by side and arranged to move along one wall, a strut associated with each carriage and having a slot at its lower end and a pivotal mounting on each carriage engaging one of said struts a short distance from its slotted lower extremity the length of which strut above the pivotal connection together with the distance of the pivotal connection from the bottom of the carriage is greater than the distance between the walls so that each strut is inclined to the vertical, two projections mounted to reciprocate along the carriages and arranged to engage slotted extremities of the 10 struts respectively, spring means arranged on each side of each projection and engaging a fixed part of the carriage so as to maintain the engagement of each carriage and strut with said walls, driving means on said body comprising a crank shaft having two crank pins disposed at 180, and connecting rods pivotally attached to the crank pin and two pivot pins on the struts disposed between said slot and the pivotal connections

Landscapes

  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • Conveying And Assembling Of Building Elements In Situ (AREA)

Description

Dec. 25, 1951 H, SPRAGG 2,579,981
APPARATUS FOR EFFECTING OR CONTROLLING TRAVERSE OF A BODY BETWEEN OPPOSED WALLS Filed June 19, 1945 3 Sheets-Sheet l INVQ Dec. 25, 1951 H. SPRAGG APPARATUS FOR EFFECTING OR CONTROLLING TRAVERSE OF A BODY BETWEEN OPPOSED WALLS 3 Sheets-Sheet 2 June 19, 1945 Filed Dec. 25, 1951 H. SPRAGG 2,579,931
APPARATUS FOR EFFECTING OR CONTROLLING TRAVERSE OF A BODY BETWEEN OPPOSED WALLS 3 Sheets-Sheet 3 June 19, 1945 Filed INI QNTOR ting engagement with saidopposite walls.
Patented Dec. 25, 1951 UNITED stares APPARATUS FOR EFFECTING OR CONTROL- LING TRAVERSE OF A BODY BETWEEN OPPOSED WALLS -ATENT Harry Spr g, D rbyshire, England, assignorrto Markham d; Company Limited, Chesterfidld, England, a British company Applicati n June 1 :5. Se ial Nfl- 600, 9 In Great Britain June 29, 1944 6 Claims.
' A cordi to th s inventi an pparatus for traversing or controlling the traverse of a body along and between opposed walls, such as a roof and flo o a mine, compri a str t long r than the distance between the walls, a carriage -on which said strut is oscillatably mounted,
means for loading said strut so that it and the C rriage are brought into abutting relationship with opposite walls, with the strut in an oblique position, and means for connecting the aoovesaid as mnb as'e i parts wi h. s body.
In the se where the appar us is us for traversing the aforesaid body, for example a mining machine, driving means are arranged to connect the aforesaid strut assemblage with sai body. wh ch me n e adapted to effect -relative reciprocatory movement between said as em lage and ody al n th line of traverse. 'It will be appreciated with this arrangement that when the driving means connecting the assemblage with the body effects relative movement during one stroke of reciprocation, the strut will be pivoted against the action of the loading means so as to release the assemblage from the that the oscillating movements of the struts may take place in any desired sequence, whereby the resultant movement of the body may approximate to uniform. I
The aforesaid carriage may be provided with wheels ormay comprise a sledge adapted to engage one of the said walls, and pivotally carries said strut, one end of which engages the other wall.
The loading means aforesaid may comprise spring means or a hydraulically or pneumatically operated plunger connected between said strut and said carriage so as to apply a force tending to maintain the strut and the carriage in abut- The means, for connecting the assemblage with the "body may either be secured to the carriage or may be pivotally connected'to the strut. This. arrangement is particularly suitable when the apparatus is arranged as a safety device for controlling the traverse of the body between the two walls, For example, assuming it is arranged for preventing machines or other objects hauled by ropes or chains from running away due to a breakdown of the haulage system when proceeding along a steep incline. In such an instance, the strut assemblage is either arranged to be trailed behind or pushed in front of the machine or object by means of a connecting-rod, and the arrangement of the connection is such that during normal haulage the force imparted to'the strut through the connection tends to move it out of engagement with the wall, whereas, in the event of the failure of the haulage system, there will be a reversal of the force applied to the connecting-rod, tending to jam the strut against the wall and thereby prevent run-away. In an alternative method 01 utilising the apparatus as a safety device for controlling the traverse of an object a haulage member may be connected to the strut, so that under normal haulage conditions, it tends to pull the strut free of th walls,
and the movement of the strut in this direction is limited by suitable stop means so that a haulage force is then transmitted to the body.
Should, however, the haulage system fail, and the body over-run the strut assemblage, the forces are reversed and the strut jams into the wall.
Again considering the apparatus as arranged for traversing the body, for example a mining Of a shoe which isv articulately machine, and having driving means so connecting the aforementioned strut assemblage with the body, as to eflect relative movement between these two parts, the said driving means may comprise a crank or eccentric rotatably driven and mounted on one of the parts, and a connectingrod driven thereby and pivotally connected to the other part. For example, the rotatably driven crank or eccentric may be mounted on said body, and the associated connecting-rod is either pivotally connected to the carriage or to said strut.
In any of the arrangements referred to above,
means may be provided for adjusting the eifective length of the strut so that the apparatus may be used for different distances between the opposed walls.
The operation may be assisted by the provision mounted on the free. end of the strut. v v The following is a description of one form of apparatus for traversing mining machinery along an underground working, reference being made to the accompanying drawings, in which:
Figure 1 is a sectional side elevation of the apparatus;
Figure 2 is a plan view, and
Figure 3 is an end elevation of the strut.
The apparatus comprises two sledges arranged side-by-side at ID in Figure 1 and each having a flat bottom wall ll arranged to rest on the 'mine floor. Each sledge is provided with uptilted ing arms l8 extending beyond the end of the strut so as to form a fork-piece I9. as best seen in Figure 3. Each of the brackets is provided with a supporting block 20 which carries a fulcrum pin 2| which extends through holes formed in the blocks l1 and in the web of the strut. A connecting-rod 22 has one end between the arms iii of the fork-piece l9 and is secured thereto by a pin 23 which passes through holes in said arms. The pin is secured in position by means of a plate 24 secured to one of the arms and projecting into a groove formed in the end of the pin. The extremities of the arms l8 are provided with slots 25 which embrace pins 26 projecting laterally from each side of a tubular shuttle member 21. The shuttle member is reciprocably mounted on a rod 28 fixed between two projections 29 on the bottom of the sledge. Disposed between each end of the shuttle and the nearest abutment is a compression spring 30, the two compression springs being so arranged as to bring the strut at right-angles to the bot tom wall of the sledge. Adjustably secured to the upper end of each strut are two members 50 which are secured together at their upper extremities by a spacing block 3|. The members 50 are so shaped and dimensioned as to lie flat against the web portion of the H-sectioned strut between the flanges thereof. The web portion of the strut is provided with a number of holes 32 and a hole in each of the members 50 may be brought intoregister with one of the holes in the web portion. The forked member may be retained in a required position on the strut by means of a bolt 33 which extends through the registering holes and is provided with a wing-nut 34 for clamping the assemblage in position. The spacing block carries a pin 35 projecting on each side thereof and extending through holes in side members 35 formed on the underside of a shoe 31. As in the case of the sledge, the ends of the shoe are bent away from the main plane thereof, as shown at 38, so.
as to prevent the shoe from digging into the wall. The two sledges are loosely coupled together by a number of inverted channel-shaped members 40 arranged to extend over upstanding parts 4| on the adjacent sledge.
The connecting-rod 22 is connected to a driving element which may either be formed integral with the body which requires to be moved, or may be formed as a separate unit 50 mounted on a sledge as shown in the drawings, which unit 50 may in turn be connected to the body to be moved. The driving means may comprise a compressed air motor 43 which drives an eccentric 44 through suitablegearing 45, compressed air being supplied through pipe 52. The eccentric is encircled by a strap 46 having a connecting-rod 41 secured to a lever-arm 48 on a. double-throw crankshaft 49. The crankshaft is provided with two crank-pins for connecting respectively to the two connecting-rods, which crank-pins are arranged apart on the crankshaft, so that the movement imparted to the body to be traversed approximates to uniform movement.
I claim:
1. Apparatus for traversing a body along and between opposed walls, such as the roof and floor of a mine, comprising two carriages separate from andunsupported by said body arranged to move along one wall, a strut longer than the distance between the walls pivotally mounted on each carriage at a distance away from the lower end thereof so that it is inclined to the vertical, spring means between the lower end of each strut and the carriage so as automatically to maintain the engagement of the carriage and the strut with said walls without imparting up and down thrust to the body, and a reciprocable member on said body pivotally connecting each strut and carriage assemblage to the body and to impart relative reciprocatory movement between each said carriage and the body in out-of-phase relationship.
2. Apparatus for traversing a body along and between opposed walls, such as the roof and floor or" a mine, comprising two carriages arranged to move along one wall, a strut longer than the distance between the walls pivotally mounted on each carriage so that it is inclined to the vertical, resilient yielding means automatically maintaining the engagement of each carriage and strut with said walls, driving means on said body comprising a crank shaft having two crank pins disposed at 180, and connecting rods pivotally attached to the crank pins and to the lower extremities of said struts respectively whereby reciprocatory movement is imparted to the carriages in out of phase relationship.
3. Apparatus according to claim 2, wherein means are provided for adjusting the efiective length of each strut.
4. Apparatus according to claim 2, wherein a shoe is pivotally mounted on the opposite end of said strut to said carriage.
5. Apparatus for traversing a body along and between opposed walls such as the roof and floor of a mine comprising two carriages disposed side by side to move along one wall, a strut associated with each carriage, a pivotal mounting on each carriage engaging a strut a short distance from its lower extremity, the length of each of which struts above its pivotal connection together with the distance of the pivotal connection from the bottom of the carriage is greater than the dis tance between the Walls so that each strut is inclinedto the vertical, resilient yielding means for automatically maintaining the engagement of each carriage and strut with said walls, driving means on said body comprising a crank shaft having two crank pins disposed at 180, and connecting rods pivotally attached to the crank pins and to those parts of the struts beneath their pivotal connections with the mounting whereby reciprocatory movement may be imparted to the two carriages in out of phase relationship.
6. Apparatus for traversing a body along and between opposed walls such as the roof and floor of the mine comprising two carriages disposed side by side and arranged to move along one wall, a strut associated with each carriage and having a slot at its lower end and a pivotal mounting on each carriage engaging one of said struts a short distance from its slotted lower extremity the length of which strut above the pivotal connection together with the distance of the pivotal connection from the bottom of the carriage is greater than the distance between the walls so that each strut is inclined to the vertical, two projections mounted to reciprocate along the carriages and arranged to engage slotted extremities of the 10 struts respectively, spring means arranged on each side of each projection and engaging a fixed part of the carriage so as to maintain the engagement of each carriage and strut with said walls, driving means on said body comprising a crank shaft having two crank pins disposed at 180, and connecting rods pivotally attached to the crank pin and two pivot pins on the struts disposed between said slot and the pivotal connections with the mountings whereby reciprocatory movement is imparted to the two carriages in out of phase relationship.
HARRY SPRAGG.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 185,653 Swett Dec. 26, 1876 1,116,356 Morgan Nov. 3, 1914 1,212,382 Morgan Jan. 16, 1917 1,675,723 Morgan July 3, 1928 1,710,887 Morgan Apr. 30, 1929 1,785,196 Holmes Dec. 16, 1930 2,093,448 Joy Sept. 21, 1937 2,420,755
Mavor May 20, 1947
US600379A 1944-06-29 1945-06-19 Apparatus for effecting or controlling traverse of a body between opposed walls Expired - Lifetime US2579981A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2579981X 1944-06-29

Publications (1)

Publication Number Publication Date
US2579981A true US2579981A (en) 1951-12-25

Family

ID=10910648

Family Applications (1)

Application Number Title Priority Date Filing Date
US600379A Expired - Lifetime US2579981A (en) 1944-06-29 1945-06-19 Apparatus for effecting or controlling traverse of a body between opposed walls

Country Status (1)

Country Link
US (1) US2579981A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE975639C (en) * 1953-11-17 1962-03-22 Gewerk Eisenhuette Westfalia Back cylinder for dismantling conveyor
US3739587A (en) * 1970-09-23 1973-06-19 Gewerk Eisenhuette Westfalia Mining apparatus

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US185653A (en) * 1876-12-26 Improvement in traction-engines
US1116356A (en) * 1896-11-10 1914-11-03 American Morgan Company Coal-mining apparatus.
US1212382A (en) * 1910-11-03 1917-01-16 Edmund C Morgan Mining-machine.
US1675723A (en) * 1922-07-28 1928-07-03 Morgan Olive Eugenie Mining and loading machine
US1710887A (en) * 1921-11-15 1929-04-30 Morgan Olive Eugenie Mining machine
US1785196A (en) * 1929-09-13 1930-12-16 Sullivan Machinery Co Mining machine
US2093448A (en) * 1935-05-23 1937-09-21 Sullivan Machinery Co Mining apparatus
US2420755A (en) * 1942-12-04 1947-05-20 Joy Mfg Co Apparatus for mining

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US185653A (en) * 1876-12-26 Improvement in traction-engines
US1116356A (en) * 1896-11-10 1914-11-03 American Morgan Company Coal-mining apparatus.
US1212382A (en) * 1910-11-03 1917-01-16 Edmund C Morgan Mining-machine.
US1710887A (en) * 1921-11-15 1929-04-30 Morgan Olive Eugenie Mining machine
US1675723A (en) * 1922-07-28 1928-07-03 Morgan Olive Eugenie Mining and loading machine
US1785196A (en) * 1929-09-13 1930-12-16 Sullivan Machinery Co Mining machine
US2093448A (en) * 1935-05-23 1937-09-21 Sullivan Machinery Co Mining apparatus
US2420755A (en) * 1942-12-04 1947-05-20 Joy Mfg Co Apparatus for mining

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE975639C (en) * 1953-11-17 1962-03-22 Gewerk Eisenhuette Westfalia Back cylinder for dismantling conveyor
US3739587A (en) * 1970-09-23 1973-06-19 Gewerk Eisenhuette Westfalia Mining apparatus

Similar Documents

Publication Publication Date Title
US4019549A (en) Wood splitting apparatus
US2579981A (en) Apparatus for effecting or controlling traverse of a body between opposed walls
US2681623A (en) Well pumping apparatus
US4251046A (en) Extensible beam arrangement
US3024663A (en) Tuned absorber for vibratory drive
US2805580A (en) Double stroke pumping attachment for a well pumping apparatus
US2633879A (en) Sawmill carriage dogging apparatus
US2623630A (en) Belt tensioning mechanism for conveyers
US2113281A (en) Straight lift pumping unit
US2402056A (en) Hydraulic conveyer driving mechanism
US3458153A (en) Level-wind structure
SU927128A4 (en) Powered roof support section
US1795922A (en) Well pumping unit
US3421329A (en) Oscillating ground engaging instrument
US4234163A (en) Engagement devices
US3113762A (en) Mining machine having a reciprocating cutter
US2215338A (en) Drive mechanism for shaker conveyers
DE7509548U (en) CONVEYOR FOR TRANSPORTING A SUSPENSION HOSE
US1655062A (en) Long-stroke pumping apparatus
US2810564A (en) Scraper conveyor having haulage drums for winding cables of coal planer
US2149855A (en) Safety pull rod coupling
US2587229A (en) Counterbalanced shaker conveyer
US3263802A (en) Vibratory conveyor
US1979803A (en) Straight lift pumping unit
US2399073A (en) Longwall mining machine