US2656152A - Truck for drill and mining machines - Google Patents

Description

Oct. 20, 1953 s. c. MOON TRUCK FOR DRILL AND MINING MACHINES I 5 Sheets-Sheet 1 Filed Jan. 5, 1949 II/NVE/YTOE NG C Moon,

/A4 M; 1 ATT'Y. 5

NW NE Oct. 20, 1953 s; c. M OON 'TRUCK FOR DRILL-AND MINING MACHINES Filed Jan. 3, 1949 5 Sheets-Sheet 2 [NVE/V'TOE, STERLING C. Moon,

Oct. 20, 1953 s. c. MOON 2,656,152

TRUCK FOR DRILL AND MINING MACHINES 7 Filed Jan. 3, 1949 5 Sheets-Sheet '3 Jay. 5

fivvE/vToQ 5'TERLING C. Moon,

HTT Y.

Oct. 20, S. C. MOON E TRUCK FOR DRILL AND MINING MACHINES Filed Jan. 5, 1949 5 Sheets-Sheet 4 l4 9 R vERsE?\ FORWARD U F, 85 FROM No l P M -TO 0km. (o2 TANK) f/v VE/Y T 0/? STERLING C. MooN,

FROM H02 50 Oct. 20, 1953 s. c. MOON 2,656,152

TRUCK FOR DRILL AND MINING MACHINES Filed Jan. 3,. 1949 Sheets-Sheet 5 [N VEN TOE; STERLING C. MOON,

HTT'Y Patented Oct. 20, 1953 TRUCK FOR DRILL AND lWININ G MACHINES- Sterling 0. Moon, Worthington, Ohio, assignor to The Jeffrey Manufacturing Company, a corporation of Ohio Application January 3, 1949, Serial No. 68,963

6 Claims.

This invention relates to a truck designed particularly for use in an underground coal mine and in one form adapted to support a removable mining machine and in another form adapted to support a drill mechanism.

An object of the invention is to provide a truck in which a pair of traction wheels are driven by hydraulic motors and in which there is an electric cable reel also driven by a hydraulic motor and a hydraulic circuit or system.

A further object of the invention is to provide a truck with an improved hydraulic circuit and to provide an improved hydraulic circuit, per se, in which two hydraulic pumps are provided, the

output of which is delivered to a pair of traction hydraulic motors and a cable reel hydraulic motor and in which the output of only one of the pumps is delivered to a drill mechanism mounted on said truck.

Still another object of the invention is to provide an improved hydraulic circuit for controlling the operation of a pair of hydraulic traction motors and a cable reel motor.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims.

In the accompanying drawings:

Fig. 1 is a side elevational view of a truck adapted to support a separate mining machine and involving certain features of my invention;

Fig. 2 is a plan view of the truck of Fig. 1;

Fig. 3 is a plan view of the truck of Figs. 1 and 2, modified, however, to support a drilling mechanism which is illustrated as carried therey;

Fig. i is a side elevational view of the truck of Fig. 3;

Fig. 5 is a sectional view on the line 5-5 of Fig. 1 of the drawings, except as indicated hereinafter, and showing particularly the two speed drive gearing from a rotary hydraulic traction motor to a wheel driving sprocket;

Fig. 6 is an elevational view of a valve assembly and operating mechanism therefor, with the valves shown in section;

Fig. '7 is a piping diagram of the system, with the drilling mechanism; and

Fig. 8 is a diagrammatic plan view of the truck Referring particularly to Figs. 1 and 2 of the drawings, the truck includes a low generally horizontal elongated mainframe or body ill, the

front end of which is. supported by a pair of laterally spaced aligned tractionwheels H and ward portion of said body It.

and carried by the main frame It and also be neath and protected by a fender I3 is a two speed power unit. The power unit for driving .the wheel 1! is designated M and the power unit for driving the wheel i2 is designated it. These power units are essentially duplicate in design except one is a right hand unit, the other a left hand unit.

Power unit 15 is illustrated in detail in Fig. 5 of the drawings and is subsequently described completely. Power unit [5 includes a main casing or housing [6 which is adapted to be removably but rigidly attached to the main frame It in a position directly ahead of the wheel 12. Rigidly but removably attached to the main casing or housing It is a transfer casing or housing !1 which supports a reversible rotary hydraulic motor i8 which constitutes the traction motor for driving the wheel l2, said motor it being supplied with hydraulic fluid, as hereinafter described.

The rotor shaft of the reversible hydraulic motor I8 is provided with a pinion It which drives a gear 2!] through a reach gear 25, all of said gears being within the transfer casing l? and being accessible by virtue of a removable cover plate 22 provided for said transfer casing ll. Gear 26 is keyed to a shaft 23 mounted on spaced anti-friction bearings, one of which is in a neck of the transfer casing H which communicates with the main casing it, the other being in a socket or recess in a removable cap of said main casing l6.

The shaft 23 is provided with an integral low speed gear 24 and has keyed thereto a large high. Spaced from the shaft 23 and parallel therewith is a driving shaft 26 which speed gear 25.

Splined to the shaft 26 for shifting movement along the axis thereofis a. shiftable double gear having a large low speed gear 29 and a small high speed gear 30. As illustrated in the drawings, the two speed gearing provided by the gears 24 and 29 in the one instance and the gears 25 and 30 in the other instance, are in their neutral positions since the composite gear 28, 3!! is positioned on the shaft 26 so that the gears thereof are out of mesh.

Cooperating with the composite gear 29, 3B is a shipper 3! which is rigidly attached to a shiftable guide rod 32 slidable axially in cylindrical guides 33 and 3% provided in removable caps forming part of the main casing H3. The guide rod 32 is provided with three spaced peripheral grooves 35 which selectively cooperate with a spring and ball detent 36 which indicates selectively three positions of the two speed gearing, namely, low speed, neutral, and high speed, the parts being illustrated in the neutral position in Fig. of the drawings,

By shifting the guide rod 32 upwardly, as viewed in Fig. 5 of the drawings, the gears '24 and 29 will be brought into mesh, providing a low speed drive from the motor 1 3 to the sprocket 21. By shifting said guide rod downwardly from the position illustrated in Fig. 5 a high speed drive will be effected by meshing the gears 25 and 3B. Shifting of the guide rod 32 is efiected by a pivoted lever or arm 37 which cooperates with a pin 38 on the shipper 3!, the lever or arm 31 being carried on a stub shaft 39 which is journaled in the end of the casing 55 and is operated by a horizontal inwardly extending operating lever 40.

In the interest of clearness, in Fig. "5 of the drawings the lever 37, shaft 39 "and lever Ml have been rotated 90 with respect to the other parts illustrated, the actual physical relation "of the lever 45 to the casing 16 being "illustrated in Fig. 2 of the drawings.

Referring to Figs. 1 and 2 of the drawings, it will be seen that the sprocket 21 of power unit It is connected by a chain 4| to a sprocket t2 rigidly attached to the traction wheel l2. A similar chain and sprocket drive is provided between the sprocket 27 of the power unit Hi and the wheel I I.

From the above description it is evident that a very compact two speed drive is provided for each of the traction wheels ll and 12 from an individual hydraulic motor. Furthermore, the power unit for each wheel, including the motor and speed reducing gearings, is located directly ahead of the wheel which it drives and is protected by the main frame, including the adjacent fender 13. This all contributes to a good distribution of weight, the location of the power units laterally of the main body carrying por tion of the truck, and the close positioning of the power unit, including the driving motor, to the traction wheel which it drives. It also makes available considerable space rearwardly of the traction wheels for other apparatus, some of which is described hereinafter.

In the truck disclosed in Figs. 1 and 2 there is a pivoted platform 83 which is pivoted on a horizontal transverse axis, at substantially its middle, by means of aligned stub shafts '44 which are preferably carried in a hollow tube welded rigid with the platform 43. The stub shafts "44 are preferably welded to the tube and extend into bearing means in the adjacent side members of the main frame Ill. The platform as is held in the position illustrated in Figs. 1 and 2 of the drawings by a pair of r'ele'asable latching pins 45 carried by the main frame it adjacent the front end thereof, which pins 45 project beneath the upper end of the platform 53 adjacent opposite sides thereof. Latching pins 55 may be withdrawn to permit the front end of the platform 43 to drop down onto the mine floor so that a mining machine, such as a shortwall or longwall type of machine, may be dragged upon the platform 23 by operating its cable which may be hooked at one end to a portion of the main frame I B.

Toward the rear end of the frame ID is a transversely extending steering wheel axle :38 having steerable wheels ll and M3 on opposite sides thereof which are interconnected in a standard manner and operated by a steering wheel 49 adjacent an operators platform 50 which is adjacent the rear right-hand side of the main frame is, The axle 56 is pivotally attached to the main frame ID at its center along a horizontal longitudinally extending axis to'provide a three-point suspension for the main frame in in "cooperation with the front wheels H and I2. The wheels 6! and 48 are received in open pockets and normally are within the lateral confines of the main frame Ill.

Adjacent the operators platform 58 and in the central rear portion of the main frame ii) there is a tank 5! for hydraulic fluid of the hydraulic system described hereinafter, to the rear of which there is an electric cable reel 52 which is driven through a chain and sprocket drive from a'reversiblehydraulic motor 5 1.

Simultaneous control for the two speed reduction gearing mechanisms l4 and I5 is provided by means of a pair of longitudinally extending rods 55, one on each side of the upstanding members of the main frame It), the forward ends of which rods are pivotally attached to the previously described levers '60, and the rearward ends of which are attached to crank arms 56 which are keyed to a horizontal transversely extending rock shaft 5'! which has an operating lever 58 adjacent one side for rocking the shaft 51 and simultaneously and similarly shifting the gears of the power units i4 and I 5.

On one side of the upstanding members of the main frame Hi and below one of the fenders l3 and between the front traction wheel l2 and the rear steering wheel 8, there is an electric motor 59 which drives a pair of hydraulic pumps 0 and 6 l From the above description it is evident that a compact flexible truck has been provided, in which there is a pair of front traction wheels, one adjacent each side of the body or main frame and near the front thereof. Each wheel is individually driven from a reversible rotary hydraulic motor through an individual two speed power transmission mechanism. The two power transmission mechanisms are simultaneously controlled from the rear of the unit by apppropriate control mechanism. Near the rear end but forward of the operatcr'"s station, which is adjacent the rearmost portion thereof and at one side, there is a pair of steerable wheels which support the rear end of the *body and provide for steering thereof. A hydraulically driven rotary electric cable reel is also provided adjacent the rear end of the body and substantially centrally't-hereof.

The above described drive mechanism for the truck is claimed in my divisional application, Serial No. 363,434, filed June .23., 1953, for "a Truck Including Improved Dr'ive Means.

Attention is now directed to Figs. 3 and 4 of the drawings where a modified form of truck is disclosed, it being understood that except for such differences as are obvious or specifically mentioned, it follows the disclosure of the truck in Figs. 1 and 2 above described.

In the truck disclosed in Figs. 3 and 4 the platform 43 has been entirely eliminated, and the main frame or body E0 carries a rigid turntable 62 upon which the boom 63 of a coal drilling mechanism 64 is mounted for swinging movement about a vertical axis. The detailed construction of the drill mechanism 65, per se, is not a feature of the instant invention and may follow, for example, the construction of the drill mechanism disclosed and claimed in the application of John S. Beltz, Serial No. 769,358, and now abandoned, entitled Power Driven and Controlled Coal Mine Drilling Machine, filed August 19, 1947.

As hereinafter pointed out, the principal significance, insofar as the present invention is concerned, is in the hydraulic circuit wherein the hydraulic circuit of the coal drilling mechanism is intimately involved in applicants novel hydraulic circuit in one form thereof.

Attention is now directed particularly to Fig. 6 of the drawings and to the construction of a 7 multiple valve unit, generally designated 65,

which forms an important feature of my invention and provides novel hydraulic controls. Ad-. jacent the operators platform 55] there is a system of levers 8.6 which may be operated to shift an upstanding linkage 61. By reference to Figs. 1, 2, 3 and 4 it may be seen that the levers 66 are, adapted to be operated from either end of the operators platform and in the arrangement of Figs. 3 and 4 are also adapted to be operated by a forwardly extending rod 68, which may be grasped by an operator, adjacent the front of truck, who is operating the various control valves of the drill mechanism 64. Operation of any of these several levers of the mechanism 66 may be employed to shift the upstanding linkage 61 in either of reverse directions from its neutral position illustrated in Fig. 6 of the drawings.

When linkage 67 is moved upward, the associated truck is caused to travel rearwardly and when said linkage is moved down it is caused to travel forwardly. The linkage mechanism 61 is interconnected with three bell crank levers 69, 10 and H which are pivoted to the main frame and each of which is connected to an individual spool, or what may broadly be considered an individual valve of the valve unit 65; the spools or operating mechanisms associated with the levers 69, It and TI being designated 12, 13 and M, respectively. In effect, each of these spools l2, l3 and M represents an individual reversely operable control valve which while the essential characteristics are of standard design, nevertheless is designed particularly for the particular hydraulic circuit here involved.

Of particular importance is the fact that while the levers $9 and H are. connected to partake of reverse movement with the linkage El, there is a lost-motion connection-provided by an elongated slot '85, between the lever is and the linkage st so that spool it is moved only in one, direction from its normal position; that is, it is moved inwardly when the linkage 61 is moved upwardly. It does not move from its normal position when the linkage 6'! moves downwardly. Stated another way, when linkage it? moves upwardly, all three of the spools l2, l3 and I l are moved inwardly or to the right, as. viewed in 6. Fig. 6 of the drawings. When the linkage 61 is moved downwardly, only spools l2 and 14 are actuated and they move out or to the left, as viewed in said Fig. 6. Each of these spools is provided with a self-centering spring of generally standard construction.

The valve unit 65, in the preferred and complete embodiment, is built up by combining three individual valve blocks or casings. The first valve is designated '16 and constitutes a standard form of pressure relief valve. Below the pressure relief valve 76 is the block 11 of a double valve which receives the spools l2 and i3, and for practical purposes this constitutes two individual control valves. Below the double block 11 is a block :8 which receives the aforementioned spool 14.

As hereinafter described, when the hydraulic drill is omitted the block 18 and the spool 14, together with the actuating mechanism therefor, may, if desired, be completely eliminated. However, it may, if desired, still be employed, as pointed out hereinafter. It may be stated at this time that in the hydraulic circuit illustrated in Fig. 8 the block 18 and spool is are completely eliminated. In the hydraulic circuit of Fig. 7 this block 78 and spool 15 are involved and they may be involved even though the hydraulic drill is eliminated.

The operation of the several valves of the valve unit 65 can best be explained in connection with the three operating conditions thereof in conjunction with the hydraulic circuit of Fig. 7. Assuming that the electric motor 59 is running and driving the two pumps 69 and El, it will be seen that pump 65; derives hydraulic fluid from the tank 51 through a filter over a feed pipe or conduit 19 and delivers it over a pressure pipe or conduit 8?] to a block 8i attached to the block 18. In this regard it may be noted that the relative positions of the valves are reversed in Fig. 7 as compared with Fig. 6; that is, block i8 is on top and block '5'! is on the bottom in Fig.

' '7, while the reverse condition applies to Fig. 6.

A pressure relief valve 82 is interposed in the conduit the fluid normally flowing through it without effect. A high pressure condition, however, will cause the fluid to spill over to tank 5| by way of tank pipe or conduit 83.

Pump El derives fluid from the tank 5! through a filter by way of feed pipe or corn duit 84 and delivers its output fluid under pressure to pipe or conduit 35 which leads to the pressure relief valve 76. The hydraulic fluid is preferably oil or the like.

With the valves or spools l2, l3 and TM in their normal or neutral positions, as illustrated in Fig. 6 of the drawings, the truck will be standing still and be locked in position. This will be a normal condition under which the drill mechanism 64 will be operated whenever it is present on the truck. Under these conditions the output of the pump 58 flowing through the conduit 89 and block ti will enter the bifurcated passageway 8G in the block it and will flow through the central cylindrical bore in said block to a central chamber 3'5 which is connected by a fitting to a pipe or conduit 88 which is the pressureline leading to the multiple control valve designated I39 which is the main control valve for the hydraulic drill mechanism Ed, said valve I39 corresponding with the valve its of the Beltz application, Serial No. 769,358, above identified. In other words, under these conditions pump tdsupplies the hydraulic fluid for 7. operating one or more or the hydraulic control mechanisms of the drill cs. 01 which there are a number, as disclosed in detail in said Beltz application.

Tank conduit or pipe 83 also extends to valve I39, providing a return tor the fluid from said hydraulic motors or the drill mechanism by way of valve 139 to tank 51. If the drill mechanism is eliminated, the valve of block 38 may be eliminated, together with all or its associated mechanism and this .condition is illustrated the diagrammatic piping diagram of Fig. 8 of the drawings which follows the piping diagram of Fig. 7, except for obvious diiierences or those pointed out hereinafter. Onthe other hand, even if the drill mechanism is eliminated, the block 16 and associated mechanism may, if desired, be retained. If it is retained, the pipe or conduit 88 is merely connected to tank 5i and under such conditions the circuit above described would cause the pump 5i merely to by-pass freely to tank 5 4.

Under the assumed conditions, namely, with the valves in neutral, the output of pump 61 is delivered over conduit '85 to pressure relief valve it, through which it freely flows, as evident by the provision of the through passageway seen in Fig. 6 of the drawings, the fluid being connected to a central bifurcated passageway as in the block Ti. From this passageway 85 the hydraulic fluid will flow to a central chamber as in said lock it, which chamber so is permanently connested by pipe or conduit d! to tank 5!. This provides a no-load by-pass for the pump t9. Should a high pressure develop in the line 3Z1. the standard pressure relief valve it will openate in a well known manner to interconnect the main central through passageway to a spillage passageway $32 which communicates with a passageway 83 in the block ll. Block H on the back side is provided with a passageway 96, indicated by dotted lines, which is in constant communication with the central chamber '95 and with a large end chamber $55.

Thus if pressure relief valve 16 operates it connects the pressure line or conduit 85 to tank by way of passageways 92, $3 and 94 to chamber 96 which is directly connected by conduit 9| to tank.

When the truck is trammed forward it is, of course, evident that the cable reel will have to rotate to pay out cable, unless there is a reasonable amount of slack in it. In this operation the two traction motors of the power units 14 and 15 are supplied with hydraulic fluid in parallel and the cable reel operating hydraulic motor 54 is merely by-passed; that is, its input and output conduits are connected together, thus allowing it to float and allowing the pull on the cable to rotate the reel as required. This is efiected by actuating any one of the control levers E5 to push the linkage t1 downward, which actuates valves or spools 12 and 14 by pulling them out or moving them to the left, without efiecting any actuation of valve or spool I3.

Under these conditions, the hydraulic fluid from the pump 50 is delivered, as above described, over pressure conduit 86 to the bifurcated passageway 86, from which it is now connected to a chamber 96 by the lands on the spool 14, which chamber 96 is connected by conduit 9! (see Fig. 7) to the two reversible rotary hydraulic motors of the power units M and I5 connecting them in parallel; the return line from said traction motors being by way of pipe or conduit 98.

Under the conditions just described. the conduit 9! is, of course, the pressure conduit which delivers hydraulic fluid to the two traction meters of the power units It and 1-5 in parallel. This fluid is not only delivered to said conduit 91 from the pump 50, above described, but also simultaneously delivered thereto from the pump -6 i. This path is from pum :Gl by way of pressure conduit through relief valve 16 into the bifurcated passage B9 of valve 12, thence into passageway 99 which is now in communication therewith, since the spool 12 is moved to the left, as viewediin Fig. 6. Passageway 9:9 is connected with the central chamber I00 associated with the spool or valve 13 under these conditions, since it is in its neutral position Chamber IUD is permanently and directly connected to a branch of conduit .91, as clearly illustrated in Fig. 6 of the drawings. Thus both of the pumps 50 and B! are connected in parallel and the combined output is delivered to conduit 91, including all the branches thereof, which connects the two traction motors in parallel. Conduit :98, including all branches, provides the return path for the hydraulic fluid from the traction motors of power units 14 and 15. One of these branches of conduit 98 is connected to chamber Ill! associated with spool E2 which with the spool moved to the left, as viewed in Fig. 6, as assumed, is now in communication with the end chamber which, as above described, is permanently connected to tank by means of passageway 94, central chamber .99 and conduit 9 I.

At the same time the lower branch of return conduit t8 is also connected to tank through the blocks H and 18, since chamber m2, associated with spool M, is now connected to passageway I83 which in turn communicates with passageway lflfi in block ll, and said passageway I64 being now in communication with end chamber 95.

At the same time the reversible hydraulic motor 55 for controlling the cable reel 52 is bypassed. In other words, its two conduits are connected together to allow it to rotate freely. This is effected by spool 73 which is in its neutral position and in which position it accomplishes the above result.

To this end, there is a pair of spaced chambers I95 and me associated with the spool 13, which passageways are permanently interconnected by a passageway on the back of the block Tl, said passageway being indicated by the dotted lines till. Chamber IE5 is permanently connected to a conduit 188, and chamber 106 is permanently connected to conduit I89. Conduits H38 and 189 are the output and input conduits respectively for the cable reel driving motor 5 3.

When the machine is reversed, or travels rearwardly, it is, of course, necessary to supply power to the reel motor 54 so as to reel in the cable. This is effected automatically and simultaneously with the actuation of the traction motors of the power units It and 15 to drive the truck rear- Wardly. To effect this operation the linkage mechanism 61 is lifted upward by any one of the operating mechanisms 66, under which conditions all three of the spools 12, 73 and M are actuated to the right, as viewed in Fig. 6 of the drawings.

Under these conditions, hydraulic fluid from the pump Bil delivered through the conduit 8!] flows through the bifurcated passageway 86, and the chamber 162 which, as previously described, is connected to conduit 98. Conduit 98, as above described, connects the two motors of the power units M and 15 in parallel, this now being the pressure conduit instead of the return conduit.

power units I4 and I5 are now provided by conduit 91 and the various branches of it.

As above described, the conduit 9:? leads to chamber I associated with spool I3 which is now in communication with chamber I86 under the control of said spool I3. Chamber I55, as above described, is connected with conduit I09 which leads to one side of the reel operating motor 54, delivering hydraulic fluid which is first passed through the two traction motors of power units I4 and It in parallel to said reel operating motor 54 at a reduced pressure, driving it in such a direction as to tend to reel in the cable associated therewith. The normal return line from the motor 54 is by way of conduit Ills which, as previously described, is permanently connected to chamber I05 which is now in communication with the passageway 93 which, as above mentioned, is in permanent communication with tank passageway 89 and tank chamber 90 by way of conduit ill.

The motor 54 is therefore connected in series with the two motors of units I i and is which as a pair are connected in parallel. The quantity of hydraulic fluid delivered to the motor is such as to tend to rotate the cable reel at a higher rate than is normally required to reel in the cable. This is desirable to insure that the cable will be adequately reeled in. However, to prevent breaking of the cable a pressure relief valve IIIl interconnects the conduits we and I09, it being controlled by the pressure in said conduit I09. It is set at'a relatively low pressure, such as one hundred and fifty pounds per square inch, so'that whenever there is any appreciable tension on the cable q associated with the reel 52, this pressure will be developed in line I09 and the excess fluid by-passed by valve III! to the tank line Iilll.

Associated with the relief valve I I0 I also preferably provide a bleeder valve II I which is con- In normal nected to tank 5| by a conduit II2. operation the bleeder valve III will be closed and pressure relief valve II I! will operate as above described. The function of this bleeder valve is to disable the motor 54 completely which sometimes is desirable when the truck is adjacent a working face and is carrying the drilling mechanism 64 and the operator wishes to jockey the truck back and forth to position the drill, during which time he does not desire to take up the slack in the cable but merely wishes it to lie on the floor. When the bleeder valve I I I is open, it effectively opens the by-pass valve Hi) so that it will freely by-pass any fluid de livered to conduit I09, delivering said fluid through the valve I It to tank conduit I08.

The hydraulic circuit of Fig. 8 differs only slightly from that above described. In the first place, of course, the hydraulically operated drill 64 has been eliminated. Consequently there are no conduits provided for such a device. In this system the block I8 and associated mechanism, including the spool I4 and bell crank H, are also eliminated. This calls for the principal difference between this system and that of Fig.

iii)

- duit 98.

I. In this system the output of each pump 66 and IN is delivered over conduits and to a junction block H3 where the hydraulic fluid is combined and delivered to the previously described pressure relief valve I6. The block TI is the same in the system of Fig. 8 as in the system of Fig. 7, as are the associated spools I2 and i3 and the actuating means therefor.

It may also be noted that in Fig. 8 leakage conduits II 4- for the several motors have been illustrated, by which leakage is conducted to the tank 5|. In. addition, the pressure relief valve 82 has been eliminated, but a pressure relief valve II 5 is interposed in conduit 97, and a pressure relief valve H6 is interposed in con- Spillage from these relief valves is, of'course, connected totank over an obvious line or conduit.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and applicant therefore wishes not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of the invention, what it is desired to secure by Letters Patent of the United States is:

1. A truck mounted drill including a frame, means for driving said truck including a pair of hydraulic traction motors, an electric cable reel driving motor, a drill on said frame having a hydraulic operating motor, a pair of power driven hydraulic pumps, a hydraulic circuit interconposition when moved in one direction from neutral and to adiust-only twoof said valve members when moved in a reverse direction from neutral,

said lever mechanism when moved in said one direction operating said three valves to connect the output of both said pumps to said two traction motors, and to connect the output of said two traction motors to said cable reel driving motor; said lever mechanism when moved in said reverse direction operating said two valves to connect the output of both pumps to said two traction motors, and to provide a by-pass for the cable reel driving motor, said valves operating when they and said lever mechanism are in their neutral positions to by-pass the output of one of said pumps and connect the output of the other pump to said drill operating motor.

2. A truck including a frame, means for drivsaid truck including a pair of hydraulic traction motors, an electric cable reel driving motor,

a pair of power driven hydraulic pumps, a hydraulic circuit interconnecting said pumps and motors including three adjustable valve members, means biasing said valve members to neutral position wherein the output of both pumps is Icy-passed, and reversely operable lever mechanism connected to adjust all three of said valve members to one operating position when moved in one direction from neutral and to adjust only two of said valve members when moved in a reverse direction from neutral, said lever mechanisrn when moved in said one direction operating said three valves to connect the output of both said pumps to said two traction motors, and to connect the output of said two traction motors to said. cable reel driving: motor; said lever mechanism when moved in said; reverse direction operating said two valves to connectthe output of both; pumps to said two traction motors, to provide a Icy-pass. for thecable reel driving. motor.

3.-.. A hydraulic circuit includmg. a. pair of re.- versible rotary hydraulia motors, athird h y;- draulic motor, a fourth hydraulic motor, a pair oi power driven pumps, a hydraulic circuit.- interconnecting said pumps and said. motors includin a plurality of control valves at least some; of which have: neutral and reverse operating positions, and operating: means for said valves operable to adjust all of them. when operated in one direction from neutral and operable to adjust less than all oi them when. operated in a reverse direction from neutral, said valves being operable in said one direction to connect the output of both said. pumps to said pair oi reversible rotary hydraulic motors, and to connect the output of said pair oi rotary hydraulic motors to said third motor; said valves being operable in said reverse direction to connect the output of both said pumps reversely to said pair of reversible rotary hydraulic motors, and to prov de a by-pass for the third motor; said valves operating when in neutral to by-pass theoutpu-t of one oi said pumpsand connect the output of the other pump to said fourth hydraulic motor.

4- A hydrauliccircuit including a first rotary hydraulic motor, a second rotary hydraulic motor, a pump, a hydraulic circuit interconnecting said pump and said motors, and a pair of control valves in said circuit, one of said valves having a neutral position and reverse operating, positions, the other of said valves having a neutral position and.- one operating position, said one valve being constructed to provide a by-pass for said pump when it is in its. neutral position, said two valves cooperating when said one valve is moved to one operating position and. the other valve is neutral to connect, said first rotary hydraulic motor in series with said pump and to provide a by-pass for said second rotary hydraulic motor, said two valves. also cooperating when said one valve is reversely operated and the other valve is operated from its neutral position to connect both said rotary hydraulic motors in series.

51 A hydraulic circuit including a pair of power driven pumps, a first hydraulic motor, a second hydraulic motor, a third hydraulic motor, and a hydraulic circuit interconnecting said pumps and said motors, said hydraulic circuit having three adjustable valves therein all of which have a normal position, two of which have reversely operating positions and one of which has one operating position, one of said reversely operable valves providing a by-pass for an individual one of said pair of pumps when in its neutral position, the other connecting the other pump to said third hydraulic. motor, said two reversely operable valves when operated one operating position cooperating with the third valve: to connect. both of said pumps to said first hydraulic motor and to; provide a by-pass, for said second hydraulic motor, said two valves; when operated in the reverse operating position. together with the operation. of said third: valve to its; operating position reversely connecting both of said: pumps. to said first hydraulic motor and with said second hydraulic motor;

(is Ahydranlio circuit: including a pair of power driven pumps, a first: hydraulic motor, a second hydraulic, motor, and, a hydraulic. circuit interconnecting saicl pumps and said motors, said hydraulic.v circuit three adjustable valves therein all of which have. an normal position, two of which have reversely operating positions and one. of which has one' operating position, each of said. reversely' operable valves. providing a Icy-pass tor an, individual one of said pair of pumps when it is: in its neutral position, said two reversely operable valves when operated one operating msition. cooperating with the: third valve to. conmeet both of said pumps to said first hydraulic motor and to provide a Ely-pass for said second hydraulic motor, said two valves when, operated in the reverse operating: position together with the operation of said third. valve: to. its operating position reversely connecting both of said pumps to said firsthydraulic motor and with said second hydraulic motor.

STERLING C. MOON.

References Cited in the file. of this patent UNITED STATES PATENTS Number Name Date 1,735,929 Lybaek. Nov. 19,, 1929 2,112,466 Maloon Mar. 29, 1938 2,123,897 Holmes July 19, 1938 2,215,115 Buffington Sept. 1'7, 1940 2,224,725 Felt, Jr. Dec. 10, 1940 2,229,086 Joy Jan. 21, 1.941 2,301,098 Twyman Nov. 3, 1942 2,316,926 Willett Apr. 20, 1943 2,323,493 Sloane July 6, 1943 2,334,009 Jefirey Nov. 9, 1943 2,381,109 Cartlidge Aug. 7, 1945 2,384,447 Baldwin et al. Sept. 11, 1945 2,425,089 Diaz Aug 5, 1947 2,441,925 Wege May 18, 1948 2,443,311 Ernst et al June 15, 1948 2,479,063 Forsythe Aug. 16, 1949 2,562,881 Baldwin et a1 Aug. 7, 1951 2,570,400 Stein Oct. 9, 1951 FOREIGN PATENTS Number Country Date 124,793 Great Britain Apr. 10, 1919

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