US1182453A

US1182453A - Mining-machine.

Info

Publication number: US1182453A
Application number: US53746210A
Authority: US
Inventors: Frederick D Buffum
Original assignee: EDWARD O TOOLE
Current assignee: EDWARD O TOOLE
Priority date: 1910-01-11
Filing date: 1910-01-11
Publication date: 1916-05-09
Anticipated expiration: 1933-05-09

Description

MNING MACHINE.

F. D. BUFFUIVI.

MINING MACHINE.

APPLICATION FILED IAN. II, 1910.

Patented May 9, 1916 1,2% rrhh] F. D. BUFFUM.

MINING MACHINE.

APPLICATION FILED IAN. II, 1910.

- Patented May 9,1916.

n 5 SHEETS-SHEET 3.

IYII

m sL w F. D. BUFFUM.

M|N|NG MACHINE.

APPLICATIGN FILED IAN.I\,1910.

Patented May), 1916.

F. D. BUFFUM.

MINING MACHINE.

APPLICATION HLED 1AN.11-. 1910 1 182,453. Patented May 9,1916.

5 SHEETSSHEET 5 rier is mounted.

ciple the machinevis of UNITED sTATEs .PATENT oEEIoE.

FREDERICK D. BUFFUM, 0F

GARY, WEST VIRGINIA, AssIGNoE To EDWARDA oTooLE,

oF GABY, wEsT VIRGINIA.

MINING-MACHINE.

Specification of Letters Patent.'

Patented May 9, 1916.

Application led J'anuary 11, 1910. Serial No. 537,462.

the mineral cut as fast as it is broken away from the end wall of the heading. In 'printhe same type asthe mining machine illustratedand claimed in the application for patent madefby Edward OToole, Serial No. 378,378, filed June 11, 1907, in that the cutting is done by bits or cutting tools which are attached to laterally movingco-nveyers and atthe same time are reciprocated vertically .by the swinging motions of a head on which the cutter cari v'The arrangement of actuati-ng mechanisms for swinging the head and driving the cutter .carrier orconveyer, as well as for removing the cut mineral and propellingthe ,machine as a whole, are diiferent from the parts in' the pending applif cation. referred to.

In designing the presentmachine my object hasA been to provide a -simple and stronger machine, which will be' adequate to all demands put upon it, to provide means for oscillating the cutter carrier head in such manner that the driving motor may be secured in an unchangeable position upon the frame of the machine, to provide means for more readilya'djusting 'the position of the arc through which the cutters swing, and of varying the-extent Vvof such arc independently, headings of different height without lower- -v ing the floor of the heading and without requiring adjustment'of the connections which govern the position of the arc through which the cutter head swings', to modify the means for driving the machine in such manner that the driving wheels 'may also serve for steering the machine around bends, and to modify-,and improve the machine general1y, as

will appear. and claims.

Referring to from the following specification the drawings, Figure 1 repi -resents in Side elevation a machine of the character above indicated, embodying the principles of my invention. Fig. 2 is an l* elevation 'of the rear part of such machine,

to enable the same machine to cutv -showing the rearwardly extending horizontal conveyer uide and cars in .position to receive minera discharged therefrom. Fig. 3 is a plan view of so much of the machine as is shown inFig. 1. Fig 4 isa sectional view taken on the line 4-4 of Fig. 1. Fig. 5 is a side elevation of the parts shown in Fig. 4, these last two views being on `an en- .larged scale and further illustrating the parts shown in Fig. 1. Fig. 6 is a rear elevation of the machine as seen from the left of Fig. 1, the conveyer guide beingl in section. Fig. 7 is a detailed elevation of a part ofthe driving mechanism b which the machine is propelled. Fig. 8 is another detail of this mechanism on an enlarged scale. Fig. 9 is an enlarged sectional view of the conveyer taken on the line 9-9 of Fig. 2. Fig. 10 is a sectional view of the cutter head on theline 10-10 of Fig. 3, showing the take-up ,for the cutter chain or conveyer. Fig. 11 'is across-section of the same on the line 11-11 of Fig. 3.

The same reference characters same parts in all the figures.

The machine consists of a main frame 1, which is supported byv axles 2, 3, on which are mounted traction wheels 4,`5. This frame consists mainly of vertical parallel side plates and supports-fall the operating parts of the machine.A On the vforward end of the frame, on the side. members thereof,

the side arms, constitutes the oscillating cute ter head. This cutter bar consists of two

parallelplates

11a and 11", between which are contained the sprocket wheels 12 and 13, over which the cutter conveyer 14 passes. The sprockets are arranged at opposite ends ofthe'cutter bar, the plates -of'which are space d apart suiiiciently to receive them, and

-the cutter conveyer is a chain consisting al.

ternately of blocks 15 and links'. The blocks project from the openingr between the plates 11a and 11b of the cutter bar, and carry bits or cutting tools 17, which are held at such anangle by the blocks that they extend approximately radial with respect to the path of thel cutter head, that is, perpendicular to the larc-shaped 'face of the' heading. The edges of the guideway of the cutter bar are provided with guiding strips 18, 19,'as shown in Figs. 3 and 11, and the blocks 15 which and valve mechanism. The

Y chain 38 from carry the tools or bits have lips` or flanges 20, 21, which overlie and embrace these guides. Thus the blocks are prevented from being deflected by the resistance of the mineral, as the cutter head swings up and down, and twisting of the chain is avoided. At the ends of the cutter bar the sprockets and the changing direction of the chain prevent the twisting and. overturning of the chain and bits', so that the guides 18, 19 arenotl needed at these points.

The means for operating the cutter head to vkeep the chains continuously in motion and also to oscillate the head, -as well as to drive-the other parts of the. machine is, in the embodimentof the invention here shown, a double air motor, consisting-of two cylinders with associated cranks, connecting rods motor is virtually two independent engines connected to a common shaft and supplied with compressed air or other workingagent from the same source. The engine cylinders are represented by 22 and 23 and are secured upon the outer sides of the frame side members, being bolted thereto. Each-engine has a piston in its cylinder driving acrosshead 24 through Aa piston rod through connecting rods 26- with a cran shaft 27. In the valve chest 28 of each engine is an'ordinary slide valve operated by a l valve rod 29, through a Arocker 30, and eccentric rod 31 from an eccentric 32 on the shaft. The air for driving the motor is carried through the heading in a hose which follows the machine and is connected to a pipe 34 upon the frame of the machine, in which is a throttle valve 35.` The pipe leads to a union 36 in which is a valve controlled by a. centrifugal governor 37 driven by a thecrank shaft 27, yand from which the air is distributed through pipes 39 to the valve chests of the respective agents. The air exhausted from the motor serves to ventilate the mine.

The cutter carrying chain 1'4 is driven by the air motor through a pivot shaft 40, which is journaleol in the hubs 8 of the cut- 'ter head side arms 9 and 10. This shaft has keyed to it a gear 41 with which meshes a spur pinion 42 on the crank shaft 27.l Loosely mounted upon the pivot shaft 40 near one end thereof is a bevel gear 43 meshing with a complementa] bevel gear 44 on a shaft 45. The latter shaft is directly connected to the sprocket 12 about which the cutter chain passes. A clutch 46 mounted upon the shaft 41 and operated by a lever 47 connects the gear 43 with its shaft and enables power to be ytransmitted to the cutter chain. The clutch is thrown out when the bits are being set and repaired, in order both to avoid danger of the workmen being hurt in case the engine should be carelessly started up, and to facilitate movement of the chain. The

formed on the screw 25 and connecting l the gears 43, 44 run in grease in a dust-tight casing 48, and the gears 41v and 43 also run in grease in a dust-proof casing 49.` The shaft 45 is inclosed in the housing 50 and 'is parallel with the cutter head side arms 9 and 10. In order to take up looseness of the cutter chaindue to Wear the sprocket 13 is mounted so that it may be adjusted longitudinally of the cutter bar 11. To this end the stud 51 upon which the sprocket is journaled, passes through slots 52 in the inner and outer in sliding plates 53 which are guided on the outer sides of the cutter bar. An adjusting screw 54 (Fig. 10) has a neck portion 55 journaled in a swivel block 56 and is threaded into a nut 57. The ends of the swivel block 56 and nut 57 are turned down to form trunnions which are journaled respectively in the' sliding plates 53 and in the cutter bar plates 112i and 11". A capstan head 58 is into therholes of which a bar may beinserted for turning the screw. It will be observed from Figs. 1 and 3 that with a cutter head constructed as shown and described, all the vbits or cutting tools are in action simultaneously, and that less length of chain is necessary than in the form employing two chains in which only one stretch .of each is operative at one time. It is possible, however, to substitute a different type of cutter head; for instance one having twocutter carrying chains; and for this purpose the boxes are provided with removable caps to permit ready removal therefrom of the hubs of the side arms 9 and 10. While the cutters are being moved horizontally by the chains to which they`are attached, they are also given a vertical motion by the up and down swing of the head. The means for thus swinging the head consists of an adjustable crank and connecting rod motion as follows On the pivot shaft 40 is a sprocket wheel 60 from which a chain 61 passes to a sprocket 62 on a shaft 63. This shaft has keyed to'it on each side of the machine spur pinions 64, which mesh with the large gears 65 on a parallel shaft 66, which I term the crank shaft. Slackness of the chain 61 is taken up by an idler sprocket 67 `which is vertically adjustable in a slot 68 formed in a bracket 69. On the crank gears 65 secured upon the shaft 66 are crank pins 70 which carry connecting rods 71 vpivotally connected with link blocks 72. There are two of these blocks on each side of machine arranged. in pairs, the members of each pair being connected by a wrist pin with which the connecting rod is engaged. These link blocks 72 are pivoted to rock arms 73 pivoted at their lower ends upon pins 74, which are carried by a slide 75. There are two of the arms 73 on each side of the machine arranged respectively on the .outer and inner sides of the link blocks and plates of the cutter bar and is held los slide 75, and the construction on each side of the machine duplicates that on the other, so that a description of one will suffice for both. The slide 75 is supported by a bracket 76 which projects out from the machine frame, and its upper part is confined and guided by a bar 77 connected with the bracket by uprights at each end thereof.`

The bracket and guiding bar are grooved as shown in Fig. 4 and the slide 75 is confined at the top and bottom in these grooves.

The slide is slotted vertically at its center as shown best in Fig. 5, thereby providing a guide 78 for a cross-head 79 carrying a pin 8O to which outer and inner swinging ars 81 are connected. Each of these swinging bars passes through one of the link blocks 72 and is oscillated by the back and forth movement of the latter due to the connectin rod 71. Pivoted to the upper ends of the swingin bars is a block 82 through which passes t e ends of two side rods 83, the opposite or forward ends of which pass through a block 84, pivoted at 85 to an arm 86 of the side arms 9 and 10 respectively of the oscillating cutter head. On the extreme outer ends of the side rods 83 are nuts, which prevent their being withdrawn from the blocks 82 and 84 respectively. Owing to the rotations of the eccentric shaft 63 derived from the motor through the pivot shaft 40 and chain 61 the connecting rods 71 and oscillating bars 81 are moved back and forth and this motion is communicated to the cutter head by the rods 83. The weight of the head is partly counter-balanced by springs threaded upon the side rods. Each of these rods carries a number, preferably five, of sets of concentric helical springs 85a and 86E. The springs 86 Vwhich I may call the inner springs, are surrounded and covered by the springs 85a, which I call the outer springs., In the illustration of Fig. 1 the machine is represented as though one of the outer springs had been removed to show the inclosed inner spring, but in the machine as constructed all of the inner springs are covered and concealed from view. Preferably the inner springs are of opposite pitch than the outer springs 85a. Between the abutting ends of adjacent sets of springs washer plates 87 are threaded upon the rods. They springs abut at their rear ends against the block 82 and at their forward ends bear against a cage or tra-V- eling abutment 88, to the ends of which are fastened ropes 89, the rear ends of which are connected with an' anchor plate 90 through eye bolts 91, 92 and turn buckles 93. The swinging bars 81 are connected at their upper ends by a transverse tie bai 94 to afford the greatest possible strength and stiffness, and this tie bar carries rollers 96, over which the ropes are led to prevent @hating thereof, and also for the purpose of opposite side of the machine.

supporting the ropes at such a height above the side rods 83 as to balance the weight of the springs and the cage 88 and so to prevent the side rods from sagging.

I provide for adjusting the position of the arc in which the cutter head swings in order to adjust the grade of the heading, and also provide for adjusting the extent of the swin of the-head to vary the height of the hea lng. rl`hese adjustments are accomplished by moving the slide 75 horizontally and the cross-head 79 vertically. For moving the slide 75 I provide two screws 95, 96a respectively, which are pivoted at 97 and 98 to the slide and extend through

worm wheels

99 and 100 which are internally threaded to serve as' nuts for the screws. These worm wheels are journaled in a slot in the upright 101 of the forward end of the bracket 76. A worm shaft 102 is transversely journaled in the same upright between the

wheels

99 and 100 and extends across the machine carrying on its opposite ends

worms

103 and 104 which engage with both

wheels

99 and 100 on the Hand-wheel 105 is secured to this shaft and on being rotated serves in an evident manner to move the slide 75 forward or back. This movement of the slides 75 shifts the fulcrum pointof the rocking bars 81 and so causes the path of the cutter head to be raised or lowered, whereby the grade of the head may be elevated or slanted downward.

The adjustment for the height of the heading is accomplished by a vertical screw 106 threaded through the cross-head 79 and bearing on its lower end a worm wheel 107. A worm shaft 108 extending across the machine carries worms meshing with the wheel 107 on the screw 106 on each side of the machine and carries on its end a ratchet wheel 109, with which a ratchet 110 engages. Adjustment of the screws 106 raises or lowers the rocking bars 81 through the link blocks 72, thereby varying the distance between these link blocks and the pivotal axis of the bars, whereby the extent of travel of the cutter head and thus the height of the heading may be varied. of the parts is such that adjustment for height affects only the upper limit of travel of the head and does not alter its lower limit,

whereby the height of the heading may be increased or dimlnished without changing the level of the floor. These two adjustments may be made simultaneously or independently as desired, and the making of either adjustment does not throw out the other.

The coal or other mineral cut is gathered together and carried to the rear by a conveyer, from which it is dumped into mine cars. The conveyer includes screw conveyers operating directlv in rear of the cutter The arrangement 1 head to gather the cutmaterial from the sides of the heading, a gathering chute mineral from the floor of the heading and a chain conveyer which carries the material upward and rearward through a troughor chute to an elevated which picks up the position in rear of the machine, whence the material can be discharged into cars. The gathering chute is represented at 111 and is pivoted to the front axle 3 so that its forward end may scrape the floor of the heading and follow the irregularities therein. The conveyer trough consists of a front section 112 directly in rear of the gathering chute, an upwardly inclined intermediate section l113 and a rear elevated section 114. These parts of the conveyer trough are all rigidly connected with and made a part of the machine frame. In addition there is an extension 115 pivotally connected to the rear end of the section.114 and adjustable by means hereinafter described to various heights. l

The screw conveyer is represented at 116 and consists of right and left helices on the ends of a conveyer shaft 117, which is journaled in brackets 118 on the forward end of the gathering chute. The helices extend from the sides of the gathering chute outwardly approximately as far as thejend of the cutter head. This shaft is driven from the pivtt shaft 40 by means of a chain 119 passing around sprockets 120 and 121 on the pivot shaft and conveyer shaft respectively. Any slack of the chain 119 is taken up by pulley or roll 122 carried by an arm 123 which swings around the pivot shaft and is actuated by a spring 124 connected at its other end with a plate fastened to the orward end of the gathering chute so as to hold the pulley against the slack side of the chain. Upward movement of the gathering chute' due to the pull of the chain .,119 is resisted by a spring 125.bearing at its upper end against the under side of a plate 126 and pressing downward on a nut 127 threadi ed upon a rod 128, which passes through the plate 126 and the lower end of which is secured to a bracket 129 on the forward end of the gathering chute. The pull of the chain has a tendency also'to draw down the gathering chute on the opposite side of the machine from that shown in Fig. 1 and this tendency is resisted by the similar spring on a rod 130 (see Fig. 3). Adjustable Scrapers 131 and 132 are provided on the forward end of the gathering chute for closing the gaps between the latter and the walls of the heading. These Scrapers extend laterally and may be set in or out owing to the fact that they are slotted and bolted to the gathering chute.

The screw conveyer gathers the material in front of the gathering chute, whence itis taken by a scraper conveyer. The latter consists of two chains by which scraper blades are carried. The chains pass around sprockets 133 (Fig. 3) on the screw conveyer shaft 117 and travel therefrom over the bottom of the gathering chute 111, the front conveyer section 112 and under an idler sprocket 134. Thence they travel by the inclined conveyer section 113 into the overhung portion and around an end sprocket 135. The upper stretches of the conveyer chains are carried over an idler 136 at the upper end of the inclined section 113 and under an idler 137 at thelower end of this section. The inclined portion 113 of the conveyer trough merges with the raised portion 114 on an arc of large 4radius and gradual curvature, so that the conveyer ScrapersV are enabled to travel over` this part of the trough with the minimum of resistance. The course of the conveyer chains is indicated by dot and dash lines in Figs. 1, 2 and 3 to avoid complicating the drawings by a complete representation of the chains with their scraper blades, the chains characters 137 and 137b respectively.

The conveyer trough is shown in detail in Figs. 4, 6 and 9. The bottom of the trough consists of plates 138 contained between the side plates 1 of the main frame, and its sides are formed of channels 139. Guides 140 are provided for the lower stretches of the conveyer chains throughout their entire length, these guides being supported on the bottom of the conveyer trough, while similar guides 141 for the upper stretches of the chains are mounted upon brackets 142 secured to the sides 139. The scraper blades attached at their opposite ends to the conveyer chains are represented at 143. A take-up for the conveyer is provided at the rear end of the overhung section, and consists of adjustable boxes 144 in which the shaft of the rear sprockets 135 is journaled. These boxes are contained in guides 145 in the`sides of the rear conveyer section and bear against screws 146 threaded through brackets 147.

The conveyer section 115 is adjustable angularly at its point of connection with the section 114. The connection consists of bolts 148 passing through angles 149 at the abutting ends of these sections, and a double screw 150 engaging nuts 151, carried by the sections. A capstan head 152 is formed upon the screw, whereby the latter may be turned by means of a bar. rlhe Vertical shear of the overhung section 115 is taken by bent plates 153 riveted to this section and resting on the lower flanges of the channel bars forming the sides of the section 114.

The point of discharge of the mineral is governed by a sliding gate 154 which lies beneath an opening in the bottom of the overhung section 115. This gate is a reinforced steel plate having angles 155 at its opposite Sides. To one of the angles is secured a rack being designated by the 156 resting on the flange of the channel side bar on that side of the conveyer trough, and the other angle carries rolls 157 supported by the channel on that side. A pinion 158 meshes with the rack 156 and is attached to a stud shaft 159 on which is secured a hand wheel 160. Movement of the gate enables the load to be distributed into the car without requiring the latter to be shifted, and also permits the filled car to be removed and an adjacent empty one to be substituted without spilling coal on the ground between them.

The traction wheels 4 and 5 are driven from the eccentric shaft 68 previously described. This shaft carries two eccentrics 161, from which hang eccentric rods 162 carrying a lifter bar 163. This lifter bar supports clevises 165 pivoted to pawl arms 165, which swing loosely about worm shafts 166. These shafts carry ratchet wheels 167 Xed thereto, with which pawls 168 (Fig. 8) carried by the arms 165 engage. Alsofixed upon each worm shaft is a worm 169 meshing with a worm wheel 170 loose upon the rear axle. The traction wheels 4, which are mounted upon the rear axle, are engaged with said worm wheels, there being one worm wheel for each traction wheel. On the outer ends of the rear axle are sprocket wheels in driving engagement with the respectively adjacent traction wheels, which sprockets drive, b y means of chains 173, corresponding sprockets on the forward axle 3 in driving connection with the forward traction wheels 5. The upward movement of the lifter bar acts through the ratchet and pawl mechanism and worm gearing described to give an intermittent forward motion to the traction wheels, the pawlsslipping back over the ratchets when the descent of the lifter bar allows them to be lowered.

Various rates of travel of the machine are provided for by limiting the distance through which the lifter bar is allowed to be lowered. It will be observed from Fig. 7 that the ends of the lifter bar are contained in long slots 175 in the eccentric rods 162, these slots being greater than the travel of the rods, so that it is possible to hold the lifter bar stationary in an elevated position without interfering with the movement of the eccentrics. For the purpose of either holding the bar stationary or permitting a limited downward movement I provide stop arms 176, pivoted by means of a rod 177 to the frame, which extend under the lifter bar and are connected at their rear ends to rods 178 adjustably held in brackets 179. By adjusting the rods 178 by means of nuts as shown in Fig. 7 the stop arms 17 6 may be located so as either to prevent motion of the lifter ba'r altogether, or to limit such motion so that the pawl 168 is enabled to drop back over one, two, three, i r more ratchet teeth respectively. Thus the tra vel of the, machine may be stopped altogether, amount up to the predetermined maximum.

The pawl and ratchet drive is made so that the machine may run either backward or forward. For this purpose the clevises 161 are loosely hung on the lifter bar so that the pawl arms may be swung to either-side of the ratchet wheels and the clevises will move along the lifter bar accordingly. The pawl 168 is made so that it may act in either direction, as shown in Fig. 8, having for this purpose two toes and a central projection 180 on its back. This projection is engaged by a V-pointed pin 181 yieldingly pressed inward b v a spring 182, so as to permit the necessary `yield of the pawl in traveling back over the ratchet, and to permit either toe to be made operative. The pressure of the pin and spring is adjusted by means of a set screw 188 threaded into the outer end of the socket in which the spring and pin are contained. A socket 184 is formed in the pawl arm so that a bar may be inserted for working the ratchet and moving the machine by hand. The advantage of having the traction wheels independently driven either forward or backward is vto enable the machine to be steered to carry it around curves and also to widen the heading. By backing the machine a sufficient distance and then driving it ahead on an angle, the heading may be widened sufficiently to put in a switch for car storage.

The axles are attached to the machine frame by pedestals 185, the traction worm shafts are journaled in bearings 186 joined to a bracket 187 riveted to the adjacent side plate of the machine frame.

Car-hauling is done by winches 188 on the eccentric shaft.

Tn designing this machine T have had in mind to provide sufficient strength to withstand the shocks and varying strains incident to the variation in the hardness of the material upon which it is to op rate. Although the machine is intended iainly for coal mining, yet the necessity of cutting harder mineral must be provided for, owing to the fact that bands of slate and the like occur between the scams of coal. For this purpose the framing has been made of great strength throughout and suitably braced wherever severe strains occur. The material of construction is entirely steel except for bronze journal bushings, cast iron sprockets in the conveyer, and some babbitt bearing linings for the traction wheels and eccentric rods. The cutter head is partially counterbalanced b v the springs 85 and 86L before described, in order to relieve the driving mechanism as far as possible from excessive work in raising thecutter head, and partially to equalize the power required fol the up and down strokes thereof. Enough of th( weight of the head is left unbalanced to enable it to overcome the resistance of the or it may be made any I bits in the mineral during the downstroke of the head. The work put on the driving mechanism for raising the head, therefore, is only that required to overcome this unbalanced weight, plus the resistance of the cutters or bits in the mineral. The object of this is to relieve the side rods 83 of compression and cause them to be subjected only to tension. These rods are so long that if any material compression stress were put upon them they would be deected.

As the head rises from the position shown in F ig. 1 toward a horizontal position, its center of gravity moves outward and acts on a longer arm, and the compression of the springs at the same time diminishes, but they will act at an increasing distance from the pivotal center of the head owing to the the lat-ter fact that the connection with the head is set in front of the pivot shaft and that the links are thereby raised above the pivot shaft.A The proportions of these parts are such as to cause-the unbalanced weight of the head to remain practically constant.

1. In a mining machine the combination of a main frame, a cutter head oscillatively mounted on said main frame comprising arms radial to the axis of oscillation and a cutter guide in a plane parallel to said axis and perpendicular to said arms, a cutter carrying chain located in said guide, and bits carried by said chain and projecting therefrom.

2. In a mining machine the combination of a main frame, a cutter head oscillatively mounted onsaid main frame comprising arms radial to the axis of oscillation and a cutter guide in a plane parallel to said axis and perpendicular to said arms, a cutter carrying chain located in said guide, and bits fcarried by said chain and projecting therefrom, a shaft rotatively mounted in the axis of oscillation of said cutter head, and a second shaft extending from near one end of said guide toward and into driving mesh with the lirst named shaft, and a sprocket in the plane of said guide secured to said second shaft for driving said chain.

8. A mining machine comprising a frame, a cutter head pivotally attached to said frame so as to swing up and down, motor, a crank driven rotatably by said motor, a rocking member oscillated continuously by said crank, a link connection from said rocking member lto said head, whereby is swung about its pivot, and a counter-balancing spring acting upon said oscillating member and tending to move the same in such direction as will elevate the cutter head.

4. A mining machine including an oscillating cutter head, a driving motor connected with said head for swinging the same back and forth, mechanism through which a driving continuous motionof the motor causes the head to reverse its motion automatically, and a spring bearing upon said head tending to swing the same in one direction.

5. A mining machine comprising a body, a cutter head pivotally attached to the forward end of said body, a rocker having engagement with said head at a point eccentric to the axis thereof, means for oscillating said rocker, and a means for shifting the position of such rocker to alter the position of the arc in which the cutter head swings.

G. A mining machine comprising a body, a cutter head pivotally attached to the forward end of said body, a rocker having engagement with said head at a point eccentric to the axis thereof, means for oscillating said rocker, and a means for altering the extent of swing of said rocker to change the extent of swinging of the head.

7. A mining machine comprising a body, a cutter head pivotally mounted upon said body and arranged to swing about its pivot, a driving crank, an intermediate rocker between said crank and cutter head, connecting rods extending from said rocker to said crank and cutter head respectively whereby oscillating movement is transmitted to the head, and provisions for changing the distance between the fulcrum of said rocker and the point of connection with one of said connecting rods.

8. A mining machine comprising a body, a cutter head pivotally mounted upon said body and arranged to swing about its pivot, a driving cran an intermediate rocker between said crank and cutter head, connecting rods extending from said rocker to said crank and cutter head respectively, whereby oscillating movement is transmitted -to the head, and means for shifting the fulcrum point of said rocker to vary the position of the path of the cutter head.

9. A mining machine comprising a body,

'a cutter head pivotally mounted upon said body and arranged to'swing about its pivot, a driving crank, an intermediate rocker between said crank and cutterl head, connecting rods extending from said rocker to said crank and cutter head respectively, whereby oscillating movement is transmitted to the head, and means for shifting the point of connection between said rocker and one of said connecting rods whereby the amplitude of swing of the cutter head may be varied.

10. A machine for cutting passage ways in mines, comprising a movable body, a cut` ter head mounted pivotallv upon said body to swing across the face of the opposing material at the end of the passage way, mechanism for so swinging said cutter head, means for shifting the path in which said cutter head swings, whereby to alter the grade of the passage way, and means for varying the upper limit of travel of the head, whereby the height of the passage way may be varied. y

11. A mining machine comprising a main frame, traction wheels by which said frame is supported, a cutter head mounted upon the forward end of the machine so as to swing up and down, mechanism for rotating said traction wheels to drive the machine forward, and mechanism for swinging said head up and down, said mechanism including means operable while the machine is in motion for altering the amplitude and the position of the travel of the cutter head.

12. A mining machine comprising a body, a cutter head attached to said body in such manner as to oscillate about a generally horizontal axis, mechanism including a crank, a connecting rod, a rocker engaged with said connecting rod and connected to the head, for oscillating said cutter head, and means for changing the distance between the fu]- crum of said rocker and the point of its engagement with said connecting rod to vary the extent of travel of the cutter head.

13. A mining machine comprising a body. a cutter head` a driving crank, a pivoted rocker, a connecting rod between said crank and rocker and a connecting rod between said rocker and cutter head, the fulcrum of said rocker being adjustable in the direction of the second connecting rod to shift the location of the path in which the cutter head travels.

14. A mining machine comprising a body, a cutter head, a. driving crank, a pivoted rocker, a connecting rod between said crank and rocker, and a connecting rod between said rocker and cutter head, the po'ints at which said rocker is engaged with the connecting rods being at respectively different distances from its fulcrum.

15. A mining machine comprising a body, a cutter head, a driving crank, a pivoted rocker, a connecting rod between said crank and rocker, a connecting rod between said rocker and cutter head, and means for varying the distance between the point at which one of said connecting rods is engaged with said rocker and the fulcrum of the latter, whereby the amplitude of swing of the cutter head may be varied.

16. A mining machine comprising a main frame, a cutter head pivotally connected with said frame so that it may oscillate thereon, a rocker, a connecting rod between said head and rocker, a driving crank and a connecting rod engaged with said crank and rocker, the parts being so arranged that when at one limit of their travel the rocker is approximately perpendicular to said connecting rods, whereby the distance between the fulcrum of said rocker and the point of its engagement with one of said connecting rods may be varied without moving the cutter head.

17. A mining machine comprising a main frame, a cutter head pivotally connected with said frame s0 that it may oscillate thereon, a rocker, a connecting rod between said head and rocker, a driving crank and a connecting rod engaged with said crank and rocker, and means for varying-the distance between the fulcrum of said rocker and the point of engagement between the latter and one of said connecting rods, whereby the amplitude of swing of the cutter head may be varied, the said parts being sc arranged that when in one limit of their travel the rocker is approximately perpendicular to the connecting rods, whereby said variation between the connecting rod and rocker alters only one limit of travel of the putter head.

18. In a mining machine a swinging cutter head, a driving crank, a pivotally mounted rocker, connecting rods extending from said crank and cutter head respectively to said rocker and engaged therewith, and means for shifting the pivotal support of said rocker in two directions at right angles to each other, whereby the amplitude and position of the path of travel of the cutter heal may be varied.

19. In a mining machine a swinging cutter head, a driving crank, a pivotally mountedlrocker, connecting rods extending from said crank and cutter head respectively to said rocker and engaged therewith, and means for shifting the fulcrum 0f said rocker longitudinally of the machine, whereby the position of the path of movement of the cutter head, and consequently the grade of the heading, may be varied.

20. In a mining machine a swinging cutter head, a driving crank, a pivotally mounted rocker, connecting rods extending from said crank and cutter head respectively to said rocker and engaged therewith, and means for moving the pivotal point of said rocker toward and from the point of connection between the rocker and one of said connecting rods, whereby the amplitude of swing of the cutter head may be varied.

21. In a mining machine, a cutter head mounted to move in an arc across the face of the material in front of the machine, sprocket wheels mounted on said head in a plane tangent to such are, a cutter-carrying chain passing over said sprocket wheels, being thereby held with both stretches parallel to and equally distant from the axis of oscillation of the head, cutters or bits secured to said chain and projecting forwardly from the plane occupied by the chain, a shaft coaxial with the center of said arc, and a second shaft radial to said arc driven by the rst shaft, and connected to one of said sprockets to drive the chain.

22. In a mining machine a frame, a cutter head pivoted t0 said frame having a guide upon its outer or swinging end, a chain arranged in said guide, cutting tools or bits secured to said chain, sprocket Wheels about which said chain is carried, a shaft arranged concentrically with the axis of said cutter head and a second shaft geared to said firstnamed shaft and connected with one of said sprockets for driving the chain and cutters.

23. In a mining machine the combination with the frame of said machine of an arm -pivotally connected on said frame so as to oscillate thereon, a cutter guide secured to the outer end of said arm, sprockets carried by said cutter guide in a plane perpendicular to said arm, a chain passing about said sprockets, cuttingtools for bits secured to said chain, and a shaft parallel to said arm for'driving one of said sprockets and thereby driving the chain;

24. In a mining machine the combination with the frame of said machine of an arm pivotally mounted on said frame, so asto oscillate thereon, a cutter guide secured to the outer end of said arm, sprockets carried by said cutter guide, a chain passing about said sprockets, cutting tools or bits secured to said chain, a pivot shaft arranged concentrically with the pivotal axis of said arms, means for rotating said shaft and a second shaft geared to Said first-named shaft and driven therebyhaving a connection with one of said sprockets to drive the latter and thereby the chain and cutters.

In testimony whereof I have affixed my signature, in presence of two witnees.

FREDERICK D. BUFFUM.,

Witnesses:

W. C. GREENAWALT, T. A. MURPHY.