US2441582A - Loading machine - Google Patents

Description

May 1 8, 1948. J. B. McDAm-z LOADING MACHINE Original Filed Aug. 8, 1945 8 SheetsfSheej; 1

J. B. MCDADE LOADING MACHINE May ,18, 1948.

8 Sheet-Sheet 2 Original Filed Aug. 8, 1945 May 18, 1948. J, B, McDADE LOADING MACHINE original Filed Aug. 8.. 1945 l a sheets-sheet s J. B. MCDADE LOADING momma* May 1.8, 1948.

original Filed Aug. 8, 194s 8 sheds-sheet 4' alu-uli f SQ @N MMNN May 1s, 194s. I l J, B, Mc-DADE 2,441,582

LOADING MACHINE original Filed Aug. a, 1945 s sheets-sheet 5 Tw/w50?" Jm .E

J. B. Mc'DADE LOADING MACHINE May 18, 1948.

Original Filed Aug. 8', 1945 8 Sheets-Sheet 6 J. B. MCDADE LOADING MACHINE May 18, 1948.

Original Filed Aug. 8, 194.5v I 8 Sheets-Sheet 7 May 18, 1948. J. B. McDAD LOADING MACH'INE Original Filed Aug. 8, 1945 8 Sheets-Sheet 8 -Patented i May 18, 1948 Original application August 8, 1945, Serial No.

609,551. Divided and this application November 14, 1945, Serial No. 628,592

14 Claims. (Cl. 214-137) My invention relates other material.

The present application is a division of my copending application, Serial No. 609,551, filed August 8, 1945, and is directed to a species notv retained in the parent application.

The main functional purpose of my invention is to provide a coal loading machine suited to use .where the passageway in which the loader'operates is low and the space between supports within which the loading head must withdraw for bucket discharge is narrow vor is constrlcted by the position and relation of the supports.

A further purpose is to provide a coal loader in which the insertion of the empty loader shovel and the withdrawal of the loaded shovel do not require overhead support or in which the support can be maintained very close to the ground.

A further purpose is to provide a loading head which can be engaged with-the cut pile of coal bydirect thrust and in which continued thrust carries the shovel forwardly through the pile of coal and upwardly to ll and lock the shovel in upward filled position ready for withdrawal.

A further purpose is to project a scoop or shovel from a position outside a narrow vein of coal into a pile of coal to be loaded and at the same stroke, by the equivalent of a hammer blow, to push the scoop through the pile 'and turn it to an upright, lled position.

A further purpose is to project the scoop in a direct line into the pile of coal which is to be loaded, turn it up, withdraw it in a straight line to a convenient point and project it in a different direction for discharge, whereby the limited space available between pillars and other encumbrances may be used to the best advantage anda machine of full capacity can be projected and withdrawn to the best advantage.

In a vertically tiltable loader having a shovel head, a further purpose is to balance the weight of the shovel and the plunger mechanism in front of a tilting axis at their reducing leverages during withdrawal against the weight of the plunger in the rear of this axis at the plungers increasing leverage so that a point is 'reached in withdrawal of the shovel where the weight and leverage in front of the axis are overbalanced bythe weight and leverage of the plunger behind the tilting axis, and the loaded shovel is lifted from the floor so that it may be swung horizontally and projected to discharge.

A further purpose is to provide a shovel head carrying a rack and mounted on side rods, to project the head forward to any pre-set adjustto a loader for coal or 'able position 'by an hydraulic ram, to move the shovel forward beyond the movement of the head and to rotate the shovel to a illledposition by continued movement of the ram after the rack has ceased to move.

A further purpose is to swing a shovel-carrying operating mechanism about a horizontal center while projecting the shovel into the coal to be loaded, in using a rack which is restricted to straight line motion and a pinion which is rigid with the shovel to turn the shovel upwardly through the coal at the end of the forward strolre of theshovel and as a part of said forward movement, giving an hydraulic blow to the shovelto lift it into illled position, and subsequently retracting the shovel-operating mechanism and the shovel from the loading position.

A further purpose is to support a shovel from movement, and to revolve it at or beyond this` forward limit.

A further purpose is to support a shovel while hydraulically driving it forward to a point of intended use, to stop the forward movement at the point of use and then vertically to tilt the shovel up through a pile of material to be gathered.

A further purpose is to support a shovel or scoop upon rods lto an adjustable limit of forward position, to drive the shovel forward and into the coal by an hydraulic ram generally limited in its forward movement by the adjustable means, to gear the shovel to a rack travelling with the shovel to its adjustable initial limit, and to turn the shovel upwardly to complete the filling of the shovel by additional movement of the shovel and therefore of the gear after the rack has ceased to move forward.

A further purpose is, in the rear position of the shovel, to have the rear of the mechanism tilted downwardly with respect to its main operating position and to haveI the shovel lifted in order that when the mechanism is nearly horizontal asin the main shovel operation, the height of the center of gravity may be as high as possible is order to increase the coal capacity of the shovel. In other words, the space for coal between the gear rack and the oor should be as great as possible to give pay-load capacity."

A further purpose is to thrust a shovel forthe movement of the rack wherever it is theY intention to turn the shovel up through the pile oi material to be gathered.

A further purpose is to turn a shovel upwardly upon an axis within the body of the shovel so that as fllled, part of the load will be in the rear of the axis and the rest of it in front of the axis.

A further purpose is to gather the load by scoop action upon a shovel surface of such slope that when the shovel is tilted reversely, the load will slide from the shovel.

A further purpose is to revolve a gathering shovel forwardly and upwardly through a pile to be removed, lifting the content to upright position, to store energy in a spring by the upward movement, to latch the shovel in the raised position and to use the energy stored for kick-oil' purposes when the latch is released in order to bring the shovel to initial position.

A further purpose is to provide an hydraulically driven shovel with stop mechanism carrying a turning rack, adjustable means for determining the stopping points at which the rack may be made effective and a segment gear carried by the shovel engaging with the rack to turn the shovel up through the pile of material loaded, if and when the rack is stopped in its forward movement.

A further purpose is to secure as large a coal capacity as possible for the gathering and loading shovel.

Further purposes will appear in the specifications and in the claims.

I have preferred to illustrate my invention by a few only lof the forms in which it may appear, selecting forms which are practical and eiective and which at the same time well illustrate the invention. y

Figure 1 is atop plan view of the device of my invention.

Figure 2 is a side elevation, largely in longitudinal section upon line 2-2 of Figure 1.

Figure 3 is a longitudinal section corresponding generally with line 3-3 of Figure 2. The jack is partly broken away.

Figure 4 is a side elevation taken generally upon line 4-4 of Figure 2, and looking from the rear in the direction of the arrow toward the shovel.

Figure 5 is a side 'elevation of the shovel and its operating mechanism showing the shovel but not the other structure in two positions.

v Figure 6 is a top plan view of the mechanism seen in Figure 5.

Figure 7 is a perspective view of the shovel alone, from the open front, omitting the shoes.

Figure 8 is a perspective view of the shovel of Figure 7 from the rear, but modified by omitting the stop 2811 Figure 9 is a perspective view of the shovel of Figure 7, looking into the boots.

Figure 10 is a top plan view similar to Figure 6 but showing further detailed mechanism on the rear plate.

Figure 11 is an end elevation of the right hand end of Figure 6, the mechanism in the distance being omitted and the lock being shown as engaging a ratchet.

Figure 12 is a fragmentary longitudinal section of a modied check rod showing special latching notches.

In the drawings similar numerals indicate like parts.

Mining operations are many times rendered much more difficult by the fact that the vein of coal is so thin that the removal oi.' the coal leaves little room in which to work and from which to remove the coal which has been mined.

In thin seams, the diiilculty in getting mechanism within the chambers to gather and remove the lbroken coal has been so great in the past that the work has been done by hand, using a hand shovel and in many cases requiring the miner to lie on his side while he is attempting to scoop out the coal from the chamber. This is not only expensive but is very hard upon the men who do the work.

The present invention is intended to follow,

generally, the operation of a hand shovel which is inserted beneath the pile and is progressively turned forwardly and upwardly to a point above the pile from which point it is then withdrawn to be emptied, usually being emptied at the rear or at the side with respect to the face from which the content has been gathered.

The present invention is especially adapted to mine thin seams of coal to advantage and in the form illustrated gathers and loads in and from chambers as low in height as twenty inches.

There are various systems of mining coal. One system which will be cited because it illustrates to advantage the present invention is as follows:

Let us assume that an area of coal having a seam or vein of twenty inches thickness is to be mined and the coal is to be loaded by a loader capable of entering the seam. Haulageways to the seam will be driven at intervals as the need arises. These will follow the contour of the seam cutting the full depth of the seam. If the haulageways are to accommodate mine cars in present practice they will be ve feet high and mine cars will be used exclusively in them.

As each haulageway goes on through the seam there will be coal for twenty inches of its height and the rest will be rock. The haulageway need not be higher than the seam thickness because if the seam be twenty inches, for example, a, belt conveyor can be used the length of the haulageway to haul out the coal which has been cut or broken and is delivered to it from the chambers.

On a fifty foot spacing, if the chambers be as wide as thirty feet, with cross cuts at intervals providing for access of air to the working face, there will then be twenty feet of seam coal -left which provides pillars, left in place until it is removed as the operation is withdrawn from a section.

The chamber is successively advanced lengthwise by blasting or otherwise breaking down the coal on the face of the seam. The loader is held in position by jack pressure against the roof of the chamber and gathers the coal which has been thrown down, dumping it upon conveyors which are successively extended along the side of the chamber and which discharge into the mining cars or haulageway conveyors for ultimate withdrawal.

In Figure 1 of the drawing, one of my loaders is shown in a chamber, with a conveyor of well known type along the side of the loader.

The loader comprises generally a base 40 adapted to rest on the floor 4l of a chamber 42, a jack '43 suitable vfor engaging the roof 44 of the chambei', a turntable 45 and a tilting assembly 46, carrying a gathering arm in thc form of a thrustor or projector unit. The machine includes a power plant 41 for the operating parts, a front crosshead shovel assembly 48, a shovel 49 and stop mechanism 5B.

When the loader has been placed in the position from which it is intended to operate, it

v ported.

Because the door of the chamberbin which the loader is to operate is necessarily uneven, it is desirable that the base 40 cover a large area. It is anchored in position by a Jack 43 welded to the base and whose -upper end terminates in a socket 52 within which rests a nut 53. The interior nut thread 54 engages the thread 55 of the hardened jack point 56. The nut is rotated by a hand wheel 51 and the thread may be kept from rotating. in any way of the many known.

The turntable 45 supports the entire tilting assembly and is mounted to rotate about the jack, for convenience considered as in horizontal planes. The turntable, as seen in Figure 1, supports the gathering (vertically tilting) assembly on one side of the jack position and a power plant for the gathering assembly on the opposite side thereof, so placed for convenience merely in balancing. vTheoperating mechanism for the gathering assembly comprises a motor 58, a pump 59, tank 60 for the hydraulic fluid-considered here as oil, oil intake 6I for the pump, fluid control 62, connection 63 from the pump to the control inlet 64 and outlet 65 from thev control to the hydraulic cylinder 66 and return 61 from the control to the oil tank.

The hydraulic control mechanism is an operating valve merely for distributing the fluid from the pump to and from the hydraulic cylinder. It and its solenoid control are well known in the art. The valve can be operated alternatively by the solenoids 68, 69, through electrical switches 10 located at any suitable point or can be operated locally by any suitable fluid connections from a hand lever 1 I In order to accommodate tilting of the gathering assembly, the fluid connections-are made flexible.

The turntable is not merely free to turn but is turned by an electric motor 12 and suitable connections. The motor may be supported above or below the turntable as preferred but in the illustration is above the table. Upon the motor shaft 13 is located a pulley 14 connected by belt 1-5 with a pulley 16 below the turntable. The pulley 16 rotates shaft 11 carrying worm 18 engaging with worm gear 19 upon shaft 80 supported from the turntable. The shaft 80 carries a gear 8| which meshes with a fixed circular rack 82, so that the turntableis rotated with respect to its support. There are so many ways of rotating the turntable that this is suggested merely as one operative way of performing the function.

Tilting of the lgathering assembly Upon the turntable at any' point suitable to balance the power plant are located horizontal trunnions 83 about which pin the gathering assembly is capable of tilting. This tilting action is preferably left wholly to gravity. The movement of the working parts forward and back throws the center of gravity to the front or the rear, as the case may be, of a verticalline through the trunnions 83 and causes the tilting. Except as it may be desirable to -control by a lock, the tilting about the pin will be dependent wholly upon shifting of the center of gravity due to extension or retraction of the plunger and to the shovel projected and retracted by it.

The tilting assembly is free to tilt in counter- 6 yclockwise direction as viewed in Figure 2 at al! times when the moment of the weight and distance to the left of the shaft is greater than the moment of the weight and distance to the right of this shaft in the figure. However, it is desirable for certain purposes to prevent the tilting assembly from turning in clockwise direction in Figure 2 as soon as the moment of weight and distance at the right exceeds the moment of weight and distance at the left.

As an alternative for the above automatic method of tilting the gathering assembly, the tilting may be accomplished by many various and obvious mechanical means; for example an hydraulic jack such as that used in dump trucks, etc. D

At opposite sides of the cylinder sliding, bearings Illo are provided for supporting and guiding side rods I0 I, which slide freely through the bearings and which along with piston or plunger |05, are rigidly attached at their front ends to a front supporting crosshead |06, shown as made up of front and back crosshead plates I U1, |08. and at the rear of the rods to a rear plate |09.

Means of attachment of theside rods and Iof the frontend of the plunger are shown and are necessary, but their character is wholly immaterial. f

Conveniently above the side rods is located a check rod Ilo, which is supported against lateral movement in the rear plate but is free `to slide through a bearing III, supported by the rear plate.

The check rod performs two main functions; it provides for stoppage of the operating assembly to proper position for loading the shovel from a pile end, and at that position it supplies a rack by which the shovel can be turned forwardly and upwardly through the pile. The rack II 2 is located at the front end of the check rod and is f1 le to slide lengthwise with respect to the front crosshead. y It is supported against movement upwardly in the illustration by a bearing later described. The rack may to advantage be supported also on the tooth side of the rack by a bearing surface. A segment gear, to be described, supports the tooth side I I4 of the rack.

Movement is imparted by the check rod through the rack to a. gear IIS, referred to as a segment gear because a segmental part only of the gear need be used.

As shown later, the shovel will normally be locked in raised position preventing the segment gear from rotating, with the result that the segment geary and rack will move bodily together and the plunger, side rods and check rod will all y move together to the left in Figure 2.

A check finger II8 engages with stops which project into its line of travel from the relatively xed support, for the purpose of stopping movement of a check rod at any of a number of predetermined positions in order that a shovel may begin operation at a point selected as a stop. Where bulldozing is intended, the relationship is set so that the stop will not be engaged.

The upward turning movement of the shovel is continuous with its forward thrust and is so rapid that perhaps the shovel should be considered as whirled. The effect is as of a hammer blow. When it has been whirled to filled position, as elsewhere more fully discussed, it is necessa/ry that it be held' in an upturned position during the withdrawal of the shovel so that the attempt to withdraw does not reverse the whirling of the shovel and spill the contents.A For 'position of the 1 this reason a latch is required to hold the shovel in its uptumed position; and this latch also must be capable of convenient release after it has been emptied in order that the empty shovel may assume its proper horizontal position for the beginning of a new cycle.

In the use of the word shovel it is intended to include a container capable of gathering fromy a pile whether the container might be more naturally referred to as a bucket or as a scoop, for example, or not, because the present invention is considered to be applicable generally to all such types of containers having openings into which the material is gathered as the shovel is pushed forwardly. It is the intention therefore to give the shovel a generic meaning. Moreover, my invention is capable of being used as a bulldozer or even as a rake to serve the gathering purpose.

Whatever the type o shovel, it is the intention to secure it on what is effectively a geai and to mount the whole unit about an axis in a pin or other support so that the gear will mesh with the rack and shift the rack if the gear rotate without translation but to cause rotation of the gear and of the shovel if the gear travel lengthwise of the rack while meshing with it.

The shovel is front emptying; may be emptied at any point along its travel; and may be positioned at the same point for a new cycle without going back to the retracted position to release the latch holding the shovel up in loaded position. It tilts about an axis. within the body of the shovel, as distinguished from tilting about an axis outside of the shovel and has a specially advantageous-form o latch.

The runners .241i are differently placed and are in the form of what might be described rather as shoes than as runners. The shoes are shown in Figures 5 and 6 only. For some uses, neither runners nor shoes will be needed and both have been omitted from the remainder of the figures.

The shovel has unusually great capacity.

Because the shovel discharges from the front and it is desirable not to tilt it reversely to an excessive extent, lthe -fiont wall 200 slopes downwardly and inwardly to a considerable extent, as shown in Figure 5.

Since the positions of the shovel correspond to different extents of projection of the check rod I|0 at the rear end 20| in the tilting assembly and because the check rod is accessible at this point, advantage `is taken of the opportunity to latch the shovel in rested position by latchlng the check rod at its rear end exposure. This is shown in Figures 6, and 11 and will be described later.

However, With this character of latch and a iront emptying shovel, the shovel not only can be emptied at any point in the length of its travel but can be swung to its initial counterclockwise position, as compared with Figure 5, ready to start a new cycle. In connection With the latching construction of the check rod in Figure 12, the shovel furthermore is capable of latchlng with partial lling movement only of the shovel because of the presence of tortional springs 202, also to be described at a later point.

With the use of the tortional springs and the latchlng mechanism engaging a ratchet latching keeper, it will be possible to completely empty the shovel whether the shovel be initially fully filled or but partly filled. so that a new cycle may be started at any point of retraction at which it is desired to empty the shovel.

The shovel tilts by progressive driving movement of the plunger about a tilting axis by reentrantly contouring the rear ofthe shovel. In

the central part of its length a. recess 20| (Figure 7) is provided by wall 200. At opposite ends of the shovel, in line with the recesses, pockets 208 are located, not only giving additional capacity for material loaded but also placing part of the coal in these pockets in position to partially counterbalance the coal in the upper front of the shovel. l

Within the recess and between the pockets, I locate the segment IIS effective as a gear and because of the difculty in mounting it upon a pin, I pass a shaft 208 through the length of the shovel as a support for the gear. The gear engages a rack upon check rod IIO, which check rod may be stopped by a check nger. The check finger or the selector bars may be turned one with respect to the other about the check rod axis so that selectively the check fingers may iind any preferred check rod within their path of movement or the check rod may be so located as not to meet any of the selector bars and therefore as not to stop movement oi the rack and not to cause revolution of the shovel.

The last use, freeing the check nnger from selector bar engagement, will be used for special purposes where Vloulldozlng or raking is intended and a special tool is used, or where a shovel, if used, is not intended to be revolved. The check rod H0, in order to secure additional strength, is made up of a composite rod comprising an outer tubing 209 within which operates a longitudinally extending, Ire-enforcing rod ZIB (Figures 5 and 6). The finger IIb in this form is a bar 2i I (Figure 5) which is fastened in the re-enforcing rod and extends transversely through openings in the tube so that the edges of the bar are longitudinally supported by the walls of these openings.

The check rod is intended to cooperate with a shoulder sleeve 2I2 which surrounds the check rod and Which is cut a'way so as to provide progressively at different lengths along the check rod, shoulders 2I3 2I3', 2I32, etc., against which the check finger is adapted to engage selectively according to the length of travel of the check` rod intended, before the shovel reaches the position at which it is to be loaded.

Since the selector bar sleeve may be mounted about the tubing of the composite check rod, it can be turned freely about this tubing to present different shoulders within the path of movement of the check finger lI I8, which check finger, therefore, need not be rotated. Furthermore, the selector bar sleeve can be turned to a point at which the check finger will not engage any shoulder, permitting travel of the check rod along slot 2M without stoppage and therefore without any relative lengthwise movement between the rack and the gear. The slot 2 I4 may be cut all the way through 0r be cut far enough through only so that there will be no stoppage of movement of the check iinger H8. If the slot be cut all the way through, the tubing may be selected of such size as to tend to spring shut about the intermediate tubing between it and the interior rod, so as to permit the shouldered, outer tube to be retained in adjusted positions by the friction upon the intermediate tube. Advantage is taken of circumierential spring of a cut tube the size of the outer tube carrying the shoulders which may be such that it will just hug the intermediate tube with sufficient friction so as to permit longitudinal movement of the check rod through it to cause engagement of the check finger with the shoulders while having enough friction to prevent circumferential movement between the outer and the intermediate tubes. ,The shouldered selector tube may be rotated by handle 2|! to secure new positions.

Another form of selector bar and check finger construction appears in Figure 12 where the check nger 2|8 is capable of being adjusted circumferentially so as to cooperate in its longitudinal movement with selector shoulders of a type shown in Figure 5, but anchored against circumferential movement that is rigidly fixed to some suitable support. The form in Figure 1 2 has the great advantage that it can be supplied with a latch-like indicatonwhich will show the position of the particular bar or shoulder, with which the selector finger is .intended to cooperate. Because this adjustment to different selector bar positions must be made in a narrow space under cramped conditions, it is a great advantage to have the adjustment capable of being made at the extreme rear of the thrustor and to have the advantage of an indicator at this extreme end by which the position of the check finger with respect to the bars or shoulders can y be determined accurately. A further advantage in the form of Figure 12 lies in the fact that if the mechanism is capable of being set by means located wholly at the rear of the thrustor, a large part of the remainder of the mechanism can be protected by a covering 2|1 (Figure 5) with considerable advantage in protection of the mechanism.

In Figure 12 the check rod H02 may be tubular but unaltered in contour from the rack back to if latching of the full stroke only of the shovel is to be provided. On the other hand, if it be intended to latch the shovel in whatever partly rotated position it may assume, this may be provided byratcheted notches 23| (Figure 12) into any one of which the latch 230 may iit, the movement of the selector rod pushing the ratchet faces past the latch so that the latch will engage with that ratchet face farthest from the handle 228 reached by the rod as a result of the turning movement of the shovel and the reactive position of the gear in this position of the shovel upon the rack and therefore upon the check rod Aconnected with the rack. In this way, as the shovel turns in clockwise direction, as viewed in Figure 5, the latch'willbe pushed out successively by the different ratchet faces shown from ratchet face 232 to ratchet face 233; and the latch will rest in and hold at any of the intermediate locking faces 234.

One form of latch capable of use either with thesingle notch at 229 or with the ratcheted notches at 23| is shown in Figures 10 and 11. In

a point close to the position of the check finger at which point all of the mechanism shown in Figure 12 can be located. The intention is to provide a check finger 2li .which can be adjusted circumferentially and whose adjustment can be indicatedat the rear of the mechanism where the adjusting means is also located.

In the construction shown', the ltubular check rod end is threaded at 2|8 to receive a threaded stub 2|8 which should-preferably screw into the thread of the tube tightly enough to remain in adjusted position. The stub 2I8 is rigid with a check finger body 220 which carries the check finger 2I6.

1f the stub 2 I9, therefore, be screwed 1n or out of the thread in the main part of the tube, the angular position of the check finger will be changed correspondingly. It is necessary only, therefore, to provide means by which the body 220 may be turned to screw the stub 2|9 rigidly attached to it inwardly or outwardly to obtain the intended angular adjustment.

In the form shown, the body 220 isprovided with a threaded stub 22| on the opposite side of the body from stub 2|9. This threaded stub 22|, rigid with the body, is extended at 222 in order to carry a lever arm 223 which is held in pl-ace upon it as shown by a set screw 224. The threaded stub 22| and the extension in theform of shaft 222 is surrounded by a sleeve 225 which performs two functions. It is threaded upon the stub 22| to support rear ratchet recesses 226, within which will t a spring detent 221 carried by the adjusting handle 228, and the detent face desirably car-ries any type of dial bywhich the angular position may be determined fromthe end.

A further function of the sleeve 225 is that it is notched at 228 for engagement by a latch 230- not shown in Figure 12 but seen in Figure 11 these figures, the actual latch which engags in the notch or notches is located at one end of the lever 235, and is pivoted' at 236. It is spring pressed into engagement with the notch normally by a spring 23,1 and is released from this notch when the current is on the solenoid by link 238 which is the right hand link in Figure 10. When the solenoid is energized, its armature 239 is drawn inwardly in the figure with the result that lever 240 (Figure 10) is turned about its pivot 2.4i so as to pull the lever 238 outwardly in the direction of the arrow. The lever 238 is pivotally connected at 242 with the latch 230 so that as the link 238 is pulled outwardly in Figures 10 and l 11, the latch is released from the notch in which it may be engaged and is held in released position as long as current is continued through the solenoidal winding.

In the shovels seen in Figures 5 and 6, the bottom of the shovel is provided with shoes 243 and During the forward movement of the thrustor, the points 245 travel along the floor of the chamber and the front surface 246 lies substantially parallel with the floor of the chamber as seen in dotted lines in Figure 5.

During the retractive movement of the shovel While "the emptying of the shovel normally takes piace after at least partial retractive movement of the shovel, occasion arises also, of course, where the shovel is but partially filled, and where it is desired to empty the content back on the pile. Sometimes it will be desirable to discharge the content when the retractive movement is not great enough for the thrustor to tilt.

as a pendulum back beyond the point at which it would ultimately hang, and subsequently forward, repeating, until it stops. It thus moves farther back than would be necessary for the content to slide down the front wall and discharge. As later more fully explained, this pendulum action is assisted by torque springs.

In the position shown in Figure it is not the intention that the points 245 must actually engage the floor yof the chamber. Instead, they are preferably slightly lifted so as to ride above the iioor, thus riding over irregularities in kthe floor.

This lifting of the points does not interfere with the shovel properly digging under and into the pile of material to be gathered.

It is desirable to keep the tilting assembly nearly horizontal for the reason that the long end with respect to the tilting axis, whether it be the end at the rear or the shovel at the iront, must be limited in its movement to avoid striking the roof or the floor.

In Figure 5, the shovel shoes prOteCt against excessive elevation of the rear of the tilting assembly. The tilting must evidently be controlled in both directions.

I have already described the locking of the tilting assembly in its position in'which the shovel is lifted on retraction, requiring that in projected discharge position the shovel be lifted far enough from the floor for there to be room for discharge of the content.

If the runners or shoes be omitted the shovel must be held in elevated position during retraction.

In the absence of shoes (Figures '1, 8, 9) the swinging of the shovel forwardly and upwardly, as in Figure 5, would mean that the bottom'of the shovel touches the floor of the chamber un less the tilting assembly turn in counterclockwise direction about its anis.

If the Shoes be not used, it is desirable to maintain the shovel in the lifted position of Figure 5 during its entire retractive stroke in order that the shovel may not engage the floor, which would interfere with the horizont-a1 swinging movement of the shovel to a new horizontal angular position along which the shovel is to be projected to the point of discharge. In this structure, as in the earlier structures described, the tilting as sembly on retraction will tilt automatically to lift the shovel somewhat from the floor as soon as the center of gravity of the yassembly passes the tilting axis.

rIlhe shovel shown can have considerably greater capacity than those in which'the reentrant back is not used because the swinging of these reentrant back shovels about an axis passing through part of the content makes it possible to gather the content into the shovels with much less lifting effort than if the entire content be outside the axis.

Advantage is taken of this opportunity to enlarge the shovels by providing lobes, pockets, booths or boots 252, 253, (Figure 8) in the rear of the face 254 of the reentrant wall 255. These lobes comprise inner end reentrant walls 256, 251, bottom reentrant walls 258, and the outer end Walls 259, 260 of the shovel.

The supporting shaft passes through end walls 256, 251, 259, and 260, and is supported in bearings 26I, 262, welded to the walls 256, 251 in the illustration.

shovel end. Releasing of It will be evident that the fact that the shovel content is tilted about an axis through the body of the shovel greatly reduces the tilting effort required and permits the use of a shovel of greatly increased capacity, even though the capacity of the front part of the center of the shovel is reduced by the reentrant walls which permit the gear to be inset as shown.

The slip bearing 263 in Figure 7 is fastened by plates 264 to the top of side plates 265 whose lower portions are reinforced by collars 266 held to the shaft 208 by set screws 262. The shaft is thus kept from rotation.

The shaft is extended through as seen at the left hand end oi the figure at 269. Spiral springs 202' surround two ends of the shaft and are used as torsional springs in order that the springs may be wound (tightened) during filling upward movement of the shovel, to latching position so that the springs may be used to assist in the unloading reverse swinging movement of the shovel when the latch at the back of the check rod shall have been released.

The shovel revolves about the shaft and is reenforced suitably 'at 21i and 212 by collars welded to the adjacent walls of the shovel. Since the shaft is iixed against rotation, the preferably op positely wound springs 202 are connected at one end each to the shovel at 212 and at the opposite end each to the shaft at 214i. The purpose is that the springs, with whatever initial torsion may be desirable to support part of the weight of the shovel, shall be wound during and bythe upward movement of the shovel, be held by a latch such 4as that at the end of the check rod, and shall start the shovel on its swinging downward movement toward discharge when the latch is released.

The strength and character of spring will depend upon the motion expected of it. It may be selected so as to give a quick impulse to start the downward movement but be unwound before the proper discharge position is reached so as to tend to support the shovel against movement beyond proper discharge position, or it may resiliently assist in revolution of the shovel in the direction for discharge to a distance of revolution beyond normal discharge. In either event, at the time released, the shovel must be high enough above `the surface upon which there is to be discharge to permit the intended extent of swinging movement.

Either end of the spring obviously can be connected with the shovel and the other end with the shaft. In the illustration, the outer ends 215 of the springs are passed through slots 216 and the inner ends 211 of the springs are looped at 21d for engagement with pins 219 within the shaft. Y

Any suitable stop mechanism may be` used to limit the extent of movement of the segment gear along the rack and the stoppage is not limited to Geneva gear stoppage of tooth engagement as at 28d between the rack and gear nor engagement between the shovel 281 (Figure '1) and fixed surfaces 232.

The movement of the segment gear bodily along the length of the rack to produce rotary motion. of the gear and revolution of the shovel translates this bodily gear movement from reciprocating to rotary gear movement.

The shovel is pressed forward with the normal pressure-advance of the front crosshead and with the weight of the shovel resting on .the sloping forward face of the front ofthe shovel. When advance of the rack is stopped by stopping move- `ment of the check rod, the further movement of the crosshead carries the gear along the rack in the direc ion of the length of the stopped rack, rotating the gear and revolving the shovel rigid lwith it until the limit of gear travel along the rack is reached.

The shovel may be locked at the lend of its filling revolution to maintain it inthe farthest position reached, whether this be full or partial revolution. One form of lock is shown in Figures 10, 11 and 12.

As the shovel turns upwardly through the pile,

the tilting assembly would tilt in eounterclockwise direction (as viewed in Figure if means for restraining tilting be not used.

If free to tilt, the assembly, inthe absence of shovel-supporting shoes, would turn about the tilting axis in counterclockwise direction (as viewed in Figure 5) until the shovel would rest on the floor of the chamber and, during retraction of the shovel to the general position of Figure 5 '(dot-and-dash lines), would drag upon the oor of the chamber until a point is reached where the moment in the rear of the tilting axis overbalances the moment of the shovel, load and the parts in front,l at which point the assembly tilts, lifting the shovel from the chamber floor.l

When means is used to maintain the level of the tilting unit, the shovel is maintained in its partially lifted position throughout retraction to the side guiding and supporting rods which are rigidly connected with it.

y For bulldozlng use whatever shovel be used, the check rod finger is located in an angular position where it will not meet with any selector bar and consequently the check rod and the rack continue to move to the end of movement of the front crosshead.

As suggested, that selector will have been chosen which'stops the check rod and rack Just when the shovel is about to attack the pile of material to be gathered and loaded; with the result that the gear in the front crosshead begins to travel along the rack and the teeth of the shovel rigidly attached to the gear begin to '.lvolve forwardly and upwardly at the very beginning of thev approach of the contact of the shovel with the pile.

It will be noted that the identical action of the shovel takes place beginning when the check rod is stopped, no matter at what position the stoppage of the check rod takes place.

Some of the fundamental advantages of the present invention are that it gathers the coal into a suitable shovel or scoop by direct thrust, concurrently turns the shovel up through the pile of coal so as to fill the shovel fully and holds the coal securely within the shovel. Because the thrust is direct, the mechanism can be kept exany such position as that seen in Figure 5. When the center of gravity of the tilting assembly passes to the `rear of the tilting axis, theassembly will turn about the tilting axisbut merely to the position which would be reached after tilting of the form having the pinch blocks.

In operation, when fluid under pressure has been supplied to the plunger cylinder and the plunger or thrustor has started forward and has reached a point at which the torque due to weights of the front parts including the crosshead. the shovel, the side guide rods and the check rod which lie forwardof the tilting axis have overbalanced the torque due to weightsyof the remainder of the parts of the plunger, side tremely low so as to operate to its best advantage across the breast within a chamber formed by removal of the coal from a thin seam.

This greatly cheapens the loading operation. In contrast to this, at present the work must be d'one by hand, or rock must be removed in addition to the coal for the purpose only of giving room for a high and cumbersome machine.

My machine in practice telescopes to a fraction of its total operating length, adjusts to start its gathering operation in any positionshovel up through the pile to complete the illlguide rods and check rod as well as the cylinder behind the tilting axis so that in the absence of locking against tilting, automatic tilting forwardly and downwardly has ytaken place. Since the shovel is emptied and in vposition to begin gathering. the shovel has settled down upon the longer radius of its runners with its teeth in position to engage the pile to be gathered.

Remembering that the side supporting and guiding rods and the plunger (thrustor) are connected to the front crosshead, that the gear rigid with the shovel is held against rotation by the friction against the lower part of the shovel and that the rigidity of the position of the gear likewise fixes the position of the rack with respect to the other rods, it is clear that the check rod, as well as the other rods named, will travel forward with the shovel and at the same speed as the crosshead. This condition of relative speedand maintenance of initial positions of the rods with respect to the others continues until the check rod iinger meets and is stopped by that selector bar whose stopped position corresponds with the location of the pile to be handled.

When the check rod nger engages a selector, the check rod is stopped and correspondingly the rack upon the endof the check r'od is stopped; but the plunger (thrustor) continues to move and carry with it the front crosshead along with ing of the shovel.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I therefore, claim all such insofar asl they fall within the reasonable spirit and scope of my claims.

Having thus described my invention, what `I claim as new and desire to secure by Letters Patent is:

1'. In a loader, a crosshead, a thrustor connected with the crosshead, side guides for the thrustor connected with the crosshead, a check rod, a rack on the check rod, a loading'tool, a gear attached to the tool and engaging the rack, a xed shaft supporting the gear to swing the tool, and torsion springs about 'the shaft connected respectively with the tool and shaft, whereby as the tool is lifted the springs are wound.

\2. In a loader, a crosshead, a thrustor connected with the crosshead, side guides for the thrustor connected with the crosshead, a check rod, a rack on the check rod, a loading tool, a

the tool is lifted the springs are wound, and latch 15 means by which the tool may be held in lifted position.

3. A shovel having a front receiving space between the sides of the shovel and rear boots at the sides and extending rearwardly with respect to the front, a gear for the shovel and a shaft for the gear extending crosswise of the shovel through the boots. i

4. A shovel'having a lfront receiving space between the sides of the shovel and rear boots at the sides and extending rearwardly with respect to the front, a shaft extending crosswise of the shovel, a crosshead providing Journal mounting for the shaft, and spiral springs connected with the shaft and with the shovel, whereby upward movement of the shovel will cause tightening of the springs.

5. In a loader, a crosshead,'means for supporting the crosshead, a thrustor for projecting the crosshead forward and retracting the same, a gear, a shaft rotatably supporting the gear on the crosshead, a loading tool pivoting on the shaft having a reentrant rear portion and having boots on either side of the reentrant rear portion and a rack cooperating with the gear.

6. In a loader, a crosshead, means for supporting the crosshead, a thrustor for projecting the crosshead forward and retracting the same, a

gear. a shaft rotatably supporting the gear on the" "shaft having a reentrant rear portion and having boots on either side of the reentrant rear portion, a rack cooperating with the gear, a check rod connected with the rack, and a check for selectively limiting the range of movement of the check rod.

8. In a loader, a crosshead, means for supporting the crosshead, a thrustor for projecting the crosshead forward and retracting the same, a

gear, a shaft rotatably supporting the gear on the crosshead, a loading tool pivoting on the shaft having a reentrant rear portion and havingv boots on either side of the reentrant rear portion, a rack cooperating with the gear, a check rod connected to the rack, and latch mechanism for securing the check rod against forward movement with respect to the thrustor.

9. In a loader, a crosshead, means for supporting the crosshead, a thrustor for projecting the crosshead forward and retracting the same, a gear, a shaft rotatably supporting the gear on the crosshead, a loading tool pivoting on the shaft having a reentrant rear portion and having boots on either side of the reentrant rear portion, a rack cooperating with the gear, a check rod connected to the rack having latch engaging indentations, a latch having a position selectively engaging in one of the indentations for securing the check4 rod against forward movement with respect to the forward movement with the thrustor, and electromagnetic mechanism for operating the latch.

10. In a loader, a crosshead, means for supporting the crosshead, a thrustor for projecting the crosshead forward and retracting the same, a gear, a shaft rotatably supporting the gear on the crosshead, a loading tool pivoted on the shaft having a reentrant rear portion and having boots on either side of the reentrant rear portion, a rack cooperating with the gear, a check rod connected with the rack, a check for the check rod, and latch mechanism for latching the check rod against movement forward with respect to the thrustor.

11. In a loader, a crosshead, means for supporting the crosshead, a thrustor for projecting the crosshead, forward and retracting the same, a gear, a shaft rotatably supporting the gear on the crosshead, a loading tool pivoted on the shaft having a, reentrant rear portion and having boots on either side of the reentrant rear portion, a rack cooperating with the gear, a check rod connected with the rack andy spiral springs interposed hetween the shaft and the loading tool.

12. lin a loader, a shovel having a reentrant rear opening when in loaded position and boots on either side of the reentrant rear, pivot means for pivoting the shovel located in the reentrant portion and mechanism for supporting the pivot means, for projecting the same forward and retracting, and for turning the shovel about the pivot means to raise the shovel to loaded position, the shovel when moving forward having the boots extending above, the pivot means and the shovel extending downwardly farther than when the shovel is loaded and the boots extend behind the pivot means, the extra vertical height in loaded position being available for manipulation during retraction.

13. In a loader, a, thrustor, a crosshead mounted on the end of the thrustor, a pivot mounted on the crosshead, a shovel having an open face for loading, a reentrant rear portion,

Vlooots on either side thereof and a forward blade,

pivotally supported with the shovel pivot in the reentrant portion, the shovel having a length from its forward blade to the back of the boots which is substantially greater than the height, and means for turning the shovel about the pivot, whereby when the shovel is positioned with the blade down, the open face forward and the boots up it will have a maximum height and maximum open surface for loading, and when the shovel is turned to place the blade forward vand the boots rearward it will have less height and extra vertical space for manipulation during retraction.

14. A loader shovel having a reentrant rear portion, a shaft pivotally supporting the loader shovel, passing across the reentrant rear portion and giving a range of swinging movement of the shovel from emptying position to gathering and loading position, in which the container portion of the shovel lies in part behind the shaft.

JOHN B. MCDADE.

REFERENUES CHTIEID The following references are of record in the ille of this patent:

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