US2817911A

US2817911A - Trencher

Info

Publication number: US2817911A
Application number: US449685A
Authority: US
Inventors: Frank M Owen; Charles W Pewthers
Original assignee: OWEN PEWTHERS Manufacturing Co Inc
Current assignee: OWEN PEWTHERS Manufacturing Co Inc; OWEN-PEWTHERS MANUFACTURING COMPANY Inc
Priority date: 1954-08-13
Filing date: 1954-08-13
Publication date: 1957-12-31
Anticipated expiration: 1974-12-31

Description

Dec. 31,

Filed Aug F. M. OWEN El AL 2,817,911

TRENCHER 5 Sheets-Sheet 1 Frank M Owen C /7 CIT/6U" W Pe w fhem INVENTORJ I A TTO/P/Vf VJ Dec. 31, 1957 F. M. OWEN ETAL 2,817,911

TRENCHER Filed Aug. 15, 1954 5 Sheets-Sheet 2 Frank M Owe/7 C/iar/es W. Pewzbe/u" INVENTORJ' XM/f/ 1/ Z I A770 NEYJ Dec. 31, 1957 F. M. OWEN ETAL 2,817,911

TRENCHER 5 Sheets-Sheet 3 Filed Aug. 15, 1954 Frank M 0 wen Char/: W Pewzhe/J ,INVENTORS 7 AT OR/VfYJ Dec. 31, 1957 F. M. OWEN ETAL TRENCI-IER 5 Shee ts-Sheet 4 Filed Aug. 15, 1954 Frank M Owe/7 Char/es W Pewf/zer;

INVENTORS ATTORNEYJ Dec. 31, 1957 F.',M. OWEN ETAL TRENCHER Filed Aug. 15, 1954 I 5 Sheets-Sheet 5 3 f e m M m n w N e m P w. w .0 M w :1 a a m mm mm\ 9Q Unired tat$ P ge? TRENCHER Application' August 13, 1954, Serial No. 449,685" v 7 Claims, (Cl. :37-90) v;

This invention relates to trenchers and more particularly to a bucket line assembly and .power transmission system therefor adapted to be mounted on a cab and chassis truck.

Trenchers have'principally been designed for efficiency in ditch digging and little attention has been given to the roading ability of the trencher. As a consequence, it has been general custom to :provide aseparate m'eans of transportation such as a truck and lowboy trailer for transporting the-ditcher from place to'place. -In some instances, the top "road speed of the ditc-her is so small that it is not uncommon to find a separate meansof transportation used to move the ditcher distances as short as two or three miles In trenchers employing a boom type bucket line which moves substantially vertically betweenretractedposition forroading and extended position for digging, it isusually found (particularly with'heavy duty equipment) that the bucket lineextends too far-above the ground when retracted to travel over publichighways without considerable care. Accordingly many trencher designs provide for the partial dismantling of the bucket'line from-the vehicle to permit the bucket line to'-be'laid"'down in a more or less horizontal position. This partial dismantling I and reassembling of the trencher takes considerable time in part due to the amount of dismantling necessary and in part due to the weight of the parts being handled. "In

some instances the carrier structure for the bucket'lin'e is itself too high and is provided with a hinged uppe section which may be lowered for roading. 1

The heretofore available'ditchers or trenchers have provided for the digging of a trench'at a selected .depth by various means such as raisingand lowering a sub-' an obstruction which blocks the digging path and which the digger is incapable of overcoming. Slip clutches and the like have been employed in'the powertransmitting system which operates the bucket line to stop the bucket line upon striking such an obstruction'butit is .still possible to damage a trencher upon striking an obstruc tion even though the bucket line'is stopped due to the continued forward motion of the trencher. It would be advantageous to have a trencher in which means are provided which would prevent the bucket line from being-- forced into an obstruction with sufiicientforce to damage the trenchen' 1 It is sometimes necessary to dig a trenchacross'an inclined surface or to dig along a thoroughfare with the wheels on one side of the trencher on a curb which is higher than the wheels on the other side of:the' trencher;

facet- 2,817,911 Patented Dec. 31, 1957 This will cause the trench to be dug at an angle from the vertical unless some compensation is made. It has heretofore been proposed to mount the rear wheels of a trencher for vertical movement relative to the rear axle housing of the trencher but such proposal is not feasible where the wheels are driven by a ditferentialsuch as employed inthe conventional truck or where the wheels are securedyto the chassis by mounting meanswhich includes springs as is desirable in a vehicle designed for roading at high-speed. Inaddition to the need for a means for tilting the chassis relative to the wheels, it is desirable that a means be provided for spacing the chassis and wheels vertically from each other while digging so as to relievethe springs of the tremendous load imposed upon the rear wheels bythe digging action. Such means should be inoperative during roading to permit the springs to function in their normal manner.

An object of this invention is to provide a bucket line assembly which may be mounted upon the chassis of a conventional cab and chassis truck which may quickly and easily be swung between digging position and a position overlying the chassis of'the truck for roading at normal truck speeds without disassembling the apparatus in any way.

Another object is to provide a bucket line assembly in which a bucket line carrieris mounted for swinging movement on the rear end of a cab and chassis truck between a position overlying the chassis for roading at normal truck speeds anda digging position and has a bucket line movably mounted thereon in which mechanical power transmitting' means between the prime mover ofthe trencher and the buck-ct line for rotating the'same is so constructedand arranged as to permit swinging of the bucket line carrier andmovement of the bucket line thereon without disassembling any part of theuapparatus.

Another object of'this invention is to provide a bucket line assembly adapted to be mounted on a cab and chassis truck which includes'a bucket line carrier which may be swung'about an axis extending transversely of -the truck from a. digging position to a position overlying the chassis for roading and a bucket line mounted for movement along the bucket line :carrier, togetherwith means for transmitting a driving-torquefrom the truck engine to the bucket line through a drive member which is coaxial with the mounting for the carrier and which will not interfere with the freerotation of the bucket line carrier between its extreme positions. I v

Another object is to provide a bucket line assembly for mounting on a cab and chassis truck in which the bucket line may be arranged at any angle of attack for digging and may be positioned to dig at any desired depth while in such angle of'attack, said bucket line being swingable into a substantially horizontal position overlying the chassis of the truck upon which it is'mounted for roading.

Another object is to provide a bucket line assembly for-mounting on a cab and'chassis truck which will dig with the bucket line extending downwardly and rearwardly-of the truck'at a' substantial angle to the vertical to permitthe beginning of a trench closely adjacent an obstruction. p

Another objectis to provide a trencher in which the bucket line cannot be urged against an obstruction with sufiicient'force to damage the trencher.

Another object is to provide leveling means for a bucket line mounted upon a truck having spring mounted rearwheels', which will transmit'the downward force upon the bucket line-during digging directly to thewheels of the truckyby-passing' the springs whichmount such wheels, and which will permit-tiltin'g of the chassis and hence the bucket line relative to the wheels to 'diga vertical trench while the vehicle is moving across an inclined surtem for a trencher in which power delivered by the prime mover may be directly connected either to the drive wheels of the trencher or to the bucket line for operating same and a fluid pump is operated by the prime mover which pump supplies fluid for controlling the attitude of the bucket line and for operating a crowd motor which is connectable to the drive Wheels of the trencher to drive the trencher during thedigging operation.

Another object is to provide in a trencher a transmis sion system as specified in the next preceding object to gether with control levers which are provided with safety features preventing the engagement of the hydraulic pump and prime mover or the crowd motor and drive wheels while the prime mover of the trencher is connected to the drive wheels of the trencher.

Other objects, features and advantages of this invention will be apparent from the drawings and from the written specification and claims.

In the drawings wherein like reference numerals indicate like parts and wherein there is shown by way of illustration one embodiment of this invention:

Fig. 1 is a view in side elevation of a bucket line assembly embodying this invention mounted on a cab and chassis truck showing the bucket line and bucket line car rier in solid lines in a substantially vertical position preparatory for digging and in dashed outline in its position overlying the bed of the tractor for roading;

Fig. 2 is a fragmentary view in side elevation of the trencher of Fig. 1 showing the bucket line lowered and digging a trench;

Fig. 3 is a fragmentary view in side elevation showing the bucket line lowered fordigging at an angle to the vertical and reaching out behind the truck and digging adjacent an obstruction;

Fig. 4 is a fragmentary view partly in vertical elevation and partly in vertical cross section showing certain details of the apparatus;

Fig. 5 is a view along the line 55 of Fig. 4;

Fig. 6 is a fragmentary view similar to Fig. 5 showing the ditcher being operated with one wheel on a curb;

Fig. 7 is a diagrammatic view of the hydraulic control system which controls the attitude of the bucket line and operation of the crowd motor and conveyer motor;

Fig. 8 is a diagrammatic illustration of the means by which the bucket line is prevented from being forced through an obstruction;

Fig. 9 is a schematic plan view of the power transmission system of the trencher;

Fig. 10 is a schematic plan view of the levers controlling operation of the several clutches in the gear box of Fig. 9 illustrating the stops which prevent the crowd motor and fluid pump from being engaged while theprime mover is connected with the drive wheels.

The trencher illustrated comprises a bucket line mounted upon the rear end of a conventional truck of the type known as a cab and chassis truck, that is, thereis no bodyrearwardly of the cab. The apparatus and its mounting permit the truck to be operated at normal roading speeds when traveling between jobs. A power transmitting means including a gear box, a differential, and a jointed-radiating-arm chain drive is mounted rearwardly of the truck transmission and provides a means for delivering through a mechanical drive power from the engine of the truck to the bucket line. Means is also provided for delivering through a mechanical drive power from the engine to the drive wheels for reading. There is also provided means for driving a hydraulic motor which furnishes hydraulic fluid for controlling the attitude of the bucket line and for operating the conveyer belt and a crowd motor which rotates the drive wheels while the trencher is digging. This hydraulic fluid is delivered through a single control panel from which position an operator can control the speed and attitude of the bucket line.

Power is transmitted from the gear box to the bucket line through a differential which is mounted on the chassis adjacent the rear wheels with the axis of rotation of the differential axles extending transversely of the trencher. The bucket line proper is mounted upon a bucket line carrier which is pivoted to the chassis for swinging movement about the axis of rotation of these axles between a position overlying the chassis and a digging position. In this manner, the drive means between these axles and the drive sprocket of the bucket line will permit free rotation of the bucket line carrier about its pivot. The bucket line is mounted upon the carrier for movement therealong. Swinging movement of the bucket line carrier about its pivot will determine the angle of attack of the bucket line in digging and movement of the bucket line along the carrier will determine the depth of the ditch being dug. By swinging the bucket line carrier about its pivot to assume a substantially horizontal position, the bucket line will be moved into a substantially horizontal position and the over-all dimensions of the trencher with the bucket line so positioned will be such that the trencher may be driven over the public highways without difliculty.

The trencher is also provided with leveling means which control the attitude'of the chassis and hence the bucket line relative to the rear wheels and permit digging of a vertical trench while the trencher is moving across an inclined surface as well as transmitting the downward force placed upon the bucket line and chassis during the digging operations directly to the rear wheels of the trencher, by-passing the spring mounting of these wheels on the chassis.

Referring now in detail to the drawings, the truck indicated generally at 15 on which the bucket line is mounted is of the conventional cab and chassis type and may be of any make or model, preferably of two-ton capacity or more. The rear cross member of the chassis is removed so that the bucket line may operate immediately adjacent the rear axle of the truck to reduce the tendency of the bucket line to cause the truck to rear up about its rear axle. A plate or cross member 16 is welded or otherwise secured across the chassis directly above the truck differential 17 and serves to replace any structural strength of the chassis lost by the removal of the rear cross member.

Upright support members

18 and 19 are secured to plate 16 on its upper side and extend upwardly from plate 16 to provide a support means for a diflierential 20 which forms a part of the power transmission system for the bucket line.

Dilferential 20 is disposed with its driven

axle housings

20a and 20b and the axles therein extending transversely of the chassis of truck 15 and secured in

support members

18 and 19. Additional support members may be provided between the differential housing and the plate 16 but these are omitted from the drawings for the sake of clarity. The transversely extending differential 20 should extend squarely across the chassis of truck 15 as the rotational axis of the driven axles of differential 20 is the axis about which the bucket line is mounted for rotation between its roading and digging positions. While the features of the trencher could be accomplished after a fashion with this axis at a slight angle to the position shown, wherein it is normal to the longitudinal axis of the vehicle, it will be appreciated that if it were so positioned, the bucket line in its roading position would not extend parallel to the length dimension of the truck but would extend slightly crosswise thereof. Also in digging comof differential 20 so that the front and rear sides of the bucket line would track each other.

An elongate flat bucket line carrier indicated generally at 21 is journaled forrotation about

axle housings

20a and 20b of differential 20 to provide for rotation of the bucket line carrier about the axis of rotation of the driven axles of differential 20. These journals are provided by

bearings

22 and 23 journaled about housings 20a and 2012, respectively.

Bearings

22 and 23 are carried by ears 24 and 25, respectively, which ears may be Welded or otherwise secured to bucket line carrier 21.

Carrier 21 includes a pair of out-turned

channel members

26 and 27 which serve as guideway means for the bucket line and'which are spaced apart by

suitable crossbars

28, 29 and 30. Crossbar 28. and 30 are positioned at the ends of carrier 21 and. crossbar 29 extends across the carrier at an intermediate position. The carrier is provided with a spoil shield or catcher 31 which may be a thin sheet of plate secured in the rectangle provided by

channel members

26 and 27 and the two end crossbars 28 and 30. This plate serves to prevent spoil from a trench from falling from the bucket line onto the chassis and the parts of the bucket line apparatus connected thereto. This feature is of particular advantage when the bucket line is digging with its lower end extending rearwardly from a vertical plane as shown in Fig. 3 as spoil from the bucket line will fall from the line onto plate 31 in large quantity and the plate will provide a slide to conduct the spoil to the ground in front of the bucket line.

Two-way hydraulic raising

cylinders

32 and 33 are provided for swinging the bucket line carrier about its pivot and for holding the bucket line carrier at any desired angle. As shown in Figs. 4 and 5, the cylinders may be pivotably carried by the chassis as at 34 and the

extensible rods

37 and 38 of raising

cylinders

32 and 33, respectively, which are connected to pressure responsive members in the respective cylinders may be pivotably secured to the carrier 21 at 35 and 36, respectively. By two-way cylinders is meant a cylinder having a pressure responsive member such as piston 32a in cylinder 32 subject to pressure on both of its end faces. Thus, pressure fluid must be exhausted from one end of the cylinder while pressure fluid is introduced into the other end of the cylinder. This feature permits the carrier 21 to be locked in any desired rotative position by the simple expedient of blocking exhaust of the pressure fluid from either end of the cylinder. By reference to Fig. 4, it will be noted that carrier 21 abuts the rearmost edge of plate 16 when in fully raised position. This provides a stop to assist in holding the carrier in digging position at the angle at which most digging will be done.

A bucket line indicated generally at 39 is mounted on bucket line carrier 21 for movement along the length dimension of the carrier or tangentially of the pivotal axis of carrier 21. Such movement permits the bucket line to be extended beyond the carrier for digging and to be retracted for roading. The bucket line is made up of a plurality of buckets 40 linked together in the manner of a chain and stretched between a drive sprocket shown schematically at 132 (Fig. 9) and an idler sprocket shown schematically at 133 (Fig. 9) on a bucket line boom 41. Boom 41 is in two telescoping parts so as to permit the elongation thereof to take up slack in the bucket line. Suitable means not shown is provided for locking the two sections of the boom in any desired relative position. A pair of spaced

structural members

42 and 43 are secured to each side of the bucket line boom adjacent its upper or drive end. Each structural member is provided with a slide 44 (see Fig. 5) with all of the slides spaced equidistant from the bucket line boom. These slides are inturned and received in guideways formed by the outturned channel.

members

26 and 27 of carrier 21 in sliding relationship therewith to maintain the bucket line in substantially parallel relationship with carrier 21 while permitting thebucket line. to be moved along carrier 21.

T he bucket line 39 is moved along carrier 21 and held in any desired position therealong by a cable 45 which is secured to the bucket line and passes over a sheave 46 mounted on the free or upper end of carrier 21. Cable 45 is passed down over the back or underside of carrier 21, thence over a sheave 47 spaced from sheave 46 and thence tied to the carrier 21 at a point intermediate the two sheaves as at 48. Sheave 47 is carried by the connecting rod 49 of a two-way hydraulic cylinder 50 which is substantially identical in structure with cylinder 32. Cylinder 50 is positioned on carrier 21 in a manner to cause movement of sheave 47 away from sheave 46 upon extension of connecting rod 49. By pressurizing a pressure responsive member in cylinder 50 which carries connecting rod 49, sheave 47 may be moved away from the free end of carrier 21 to raise bucket line 39. It will be apparent from the arrangement of sheaves in the manner described that for every inch of movement of sheave 47 the bucket line is moved two inches. A rigging of this nature for cable 45 is preferred as it reduces the length of connecting rod 49 required to move the bucket line between its extreme positions on carrier 21.

A jointed -radiating-arm chain drive which forms a part of the power transmitting means is provided for 011- erably connecting the axles of differential 20 with head shaft 51 which carries bucket line drive sprocket 132. This chain drive includes a pair of spacer arm, one arm 52 being journaled about the axle housing 20w of differential 20 between support 18 and carrier journal 22 and the other arm 53 being journaled between carrier journal 23 and support 19 for rotation about the other axle housing 2% of differential 20. This mounting, of course, will provide for rotation of

radiatingarm

52 and 53 about the axis of rotation of the driven axles of differential 20. The free ends of

arms

52 and 53 are secured to a floating shaft 54 which extends parallel to the axis about which

arms

52 and 53 rotate andis spaced therefrom by radiating

arms

52 and 53. vA second pair of radiating

arms

55 and 56 are journaled on floating shaft 54 and on head shaft 51 outboard of

arms

52 and 53 so as to position arm 55 on one side of the bucket line and arm 56 on the other side of the bucket line. A chain drive extends from each driven axle of differential 20 to head shaft 51 andincludes on each side a sprocket 57 non-rotatably mounted on an axle of differential 20, and a sprocket 58 journaled on floating shaft 54 in line with sprocket 57 and a chain 59 received about said sprockets. A second sprocket 6 0 is journaled on floating shaft 54 and is connected to a sprocket 61 non-rotatably mounted on head shaft 51 by a chain 62. One of the pair of

sprockets

58 and 60 carried by floating shaft 54 should be tied together by a slip clutch arrangement (not shown) of any desired type-to prevent overloading of the bucket line. The other of the pair of sprockets carried by floating shaft 54 may be non-rotatably secured to each other or if desired they may be provided With a slipclutch but suchis not usually necessary where a differential is employed in the'transmission system. It will be understood that this jointed-radiating-arm transmission system permits the connection of differential 20 with bucket line 39 with the bucket line in any position along carrier 21 and with the carrier at any desired digging angle. As the

arms

52 and 53 are journaled for coaxial rotation with carrier 21,*the floating shaft 54 will not knuckle in or out uponrotation of carrier 21. Thus, by dimensioning the chain drive so that the floating shaft 54 is closely adjacent carrier 21 with the bucket line in raised position, the bucket line may be moved into a horizontal position overlying the chassis of the truck for reading without disassembling .any portion of the drive transmitting means.

When roadingthe bucket line 39 will be in the position shown in dashed outline in Fig. l and in such position the .over-all dimensions of the truck may easily be kept within reasonable limits for public highway travel with a bucket line of any desired length. While so positioned, the bucket line will not interfere with the normal roading abilities of the truck and the trencher may be moved from place to place at normal truck operating speeds. When it is desired to dig a trench, bucket line carrier 21 is raised by

cylinders

32 and 33 to the desired angle of attack for trenching. If the ditch is to begin at a drive or adjacent a building or other obstruction, then the bucket line may be at an angle to the vertical as illustrated in Fig. 3 so that a ditch may be commenced close to the obstruction. After the ditcher has moved away from the obstruction, the boom may be brought to vertical position for normal digging. Where conditions permit, the bucket line carrier will usually be moved into a vertical position before the bucket line is lowered into the ground. After the bucket line carrier is in position, the bucket line is started and the bucket line lowered to the desired depth by piston 50. The trencher may then be started across the ground to dig a trench.

It will be appreciated that with the bucket line extending in a vertical plane and closely adjacent the rear wheels of the truck that the weight of the bucket line and the downward force impressed upon the chassis by the digging operation is transmitted principally to the rear driving wheels of the truck. This improves the traction of these drive wheels. When the boom is raised and the carrier rotated about its pivot to lay the bucket line over the bed of the chassis, the center of gravity of the bucket line is forward of the rear wheels of the vehicle and does not affect normal roading of the truck.

When it is desired to move the bucket line into roading position, the bucket line is first raised to its fully raised position as shown in Fig. 1. In this position,

arms

52 and 53 extend substantially parallel to

channels

26 and 27 and floating shaft 54 is positioned closely adjacent carrier 21. The carrier 21 may then be rotated about its pivot to a position extending substantially parallel to the chassis of the truck.

Thus, there has been provided a ditcher in which the bucket line may be moved from a position overlying the chassis of a conventional truck to a substantially vertical position for digging. There has also been provided a means of mounting the bucket line carrier and the radiating-arm power transmission elements in a manner that the jointed radiating arms will not jackknife as the bucket line is rotated about the pivotal connection and there is no danger of the jointed arms jackknifing into the chassis while the bucket line is being moved into reading position. line which will dig at an angle to the vertical permitting a ditch to be commenced closely adjacent a building, a driveway or the like.

A conveyer belt indicated generally at 63 is mounted upon members 42 rearwardly of the bucket line proper and receives spoil from the bucket line and conveys it to the side of the trencher whence it is deposited on the ground. The conveyer belt is hydraulically operated and may be run in either direction so as to deposit spoil on either side of the trench being dug. The conveyer belt is also mounted for movement transversely of the trencher so as to make possible the use of a relatively short conveyer belt to convey materials to either side of the ditch being dug as will be well understood by those skilled in the art. It is pointed out that by mounting the conveyer belt on members 42 that the relationship between the conveyer belt and the bucket line is constant at all times and requires no attention from the operator.

There is also provided a hood 64 which extends over the bucket line 39 between support members 42 and from carrier 21 rearwardly to overlie the conveyor belt 63. Hood 64 will deflect spoil thrown from the buckets as they pass over the drive spindle onto the conveyor belt. Such deflection is necessary as it has been found that spoil will be thrown upwardly and rearwardly of the There has also been provided a bucket bucket line at an angle of approximately from the vertical with boom 41 in vertical position.

A follow-up scraper indicated generally at 135 is carried by supports 43 and serves to clean spoil from behind the bucket line in the usual manner.

In digging with the bucket line in substantially vertical position, substantially all of the spoil is moved to the side of the ditch by conveyer 63. However, when the trencher is digging at a substantial angle, such as shown in Fig. 3, a large amount of the spoil will tend to fall from the bucket line onto the shield 31 and slide back in front of the ditch being dug. This will result in the bucket line pushing the loose spoil to either side of the ditch and form a mound of spoil on either side of such ditch. The above is true because the buckets are full as they come from the ditch and hence cannot receive any more dirt and will push the loose dirt to either side of the ditch. This is advantageous when the ditcher is working a considerable distance ahead of a pipe laying crew as the mounds of dirt will prevent surface water from flowing into the ditch in the event of rain before the pipeline crew can lay pipe. With this feature in mind, it may on occasion be desirable to dig a trench with the bucket line at an angle to the vertical.

It is frequently desirable to be able to tilt the bucket line boom relative to the rear axle of the vehicle. Such tilting of the boom will permit the digging of a vertical ditch across a slope, the digging of a vertical ditch adjacent a curb where it is necessary for the wheels on one side of the vehicle to be on the curb and the other wheels in the street and on a lower level or the like. One leveling device should be placed on each side of the center line of the trencher and should have an extensible means which when extended will cause the chassis to be spaced from the rear axle of the trencher. Such a leveling device may be provided by

hydraulic cylinders

65 and 66, one positioned on each side of the center line of the vehicle and as shown preferably closely adjacent the rear wheels of the vehicle. These cylinders are two-way fiuid operated cylinders constructed in the same manner as cylinder 32, and are provided with

extensible members

67 and 68 carried by pressure responsive members (not shown) in

cylinders

65 and 66, respectively. Upon pres surizing of the upper face of the pressure responsive memher in cylinder 66, extensible member 68 will be moved downwardly relative to the cylinder and engage an abutment member 69 carried by the rear axle housing. Abutment member 69 is provided with an elongate half-round abutment part 70 which extends fore and aft of the trencher. The abutment surface 68a on the free end of extensible member 68 is rounded to provide a flat ended semi-spherical abutment member. By flat ended is meant that the extensible member 68 which is circular in form is provided with a sloping bevel from the outer circumference of the member inwardly toward the center thereof with the bevel flattening out as it approaches the center. This bevel will prevent a sharp line contact between extensible members 68 and half-round abutment part 70 when the truck rear axle housing is moved in a fore and aft direction of the trencher relative to the chassis. Such movement is permitted by the shackle 72a in the rear mounting of the spring as the chassis is moved upwardly or downwardly relatively to the axle housing. The use of half-round member 70 provides a contact surface on abutment 69 which is always parallel to plate 16 upon which cylinder 66 is mounted with the truck chassis tilted at any operational angle. This construction is desirable as extensible member 68 will tend to cock in cylinder 66 if its contact with abutment part 69 is not such that the transmission of force is substantially parallel to extensible member 68. Non-parallel forces will tend to cause leakage by the pressure responsive member within cylinder 66. Extensible member 67 carried by cylinder 65 cooperates with an abutment plate 71 on the rear axle hous which s pr v d slaw taa j' is t t srdim mb n 1. leveling cylinder 65 and its associated xte'nsible member and abutment plate ..are .identical with. and function in the same mannerascylinder 66-and its associate elements.

From the above it is believed apparent that there has been provideda means for leveling the chassis and hence the bucket linerelative to the-wheelshof the. trencher to permit the trencher tomove alonganinclined slope or the like and at the sametirne dig a vertical trench. It is also pointed out thatthe digging operation imposes a considerable downward force upon the bucket. line which is transmitted to the chassis. The leveling cylinders and 66 transmit this force. directly to the wheels thus by-passing the spring mounting of the. rear wheels, such springs being shown at 72. Evenwhen operating on level terrain, the levelers areused; to maintainthe rear wheels and the chassis in spaced relationship so. as to transmit this digging force directly from the chassisto the wheels. As noted above, the

cylinders

65 and 66 are two way cylinders so that a pressure fluid, may be applied to raise extensible members 67 and,- 68 and hold them in an out of-the-way position while thevehicleis tra eling between locations. This is desirable so, that the extensible members will not interfere with the normal action of the Springs during roading of the vehicle.

Levelers of the type shown-in the drawings are. capable of tilting the chassis as much as 15"v relative to the wheels. This feature may be utilized to dig a v-shaped ditch by making two passes or using two trenchers with the bucket line cocked in one directionfronrthevertical on one trencher and in the otherdirection on the other-trencher.

Fluid for operating boom control-cylinders .32 and 33, boom lifting cylinder 50 and leveling cylinders-65 and 66 as well as the fluid pump supplying fluid for'the crowd motor and for operating the conveyer 63 is provided by a hydraulic fluid system. This system. is driven by the prime mover of the vehicle and may be driven directly from the motor or may be driven from a gear box whichwill be referred to hereinafter. Although the pump is shown to be driven from the gear box in the drawings, it

is contemplated that a directdrivebetween the engine and pump might be advantageous so that the R. P. M. of the pump will be maintained at the-desired level while the trencher is pulling in a very -lo w-gear ratio-without excessive racing of the engine.

Such a hydraulic system is shownin Fig. 7 and may include a reservoir 7 2and a fluid pump73 connected in a closed circuit conduit 74 with'a bank of two way valves indicated generally at 75 *in conduit "74. By twoway valves is meant valves having a pluralityof ports which, with the controllevel in one position. can connect themput line 74a to one of two auxiliary lines while simultaneously connecting the exhaust line 74b from the valve to the other of the two lines, and whichv'vith the leverin another position willconnect these auxiliary'lines in reverse relationship, preferably, together with aneut'ral position in which flow 'through'theptwo auxiliary lines is prevented. Thus, referring'to valve 76which controls the application of fluid through conduits --77 and '78 to boom lifting

cylinders

32 and 33, when lever-79 is moved in one direction the input from line 74a will be connected with auxiliary line 78 to retract the extensible connecting

rods

37 and 38 and move the boom into its position overlying the chassis of the vehicle. -n1asmuh as

cylinders

32 and 33 are fully fluid loaded on both sides-of the'pr'es sure responsive member therein,- itis necessary that'valve 76 connect line77- to the. exhaust line 74b of the'system and permit fluid beingforcedfrom'oylinders 32 and'33'to be returned to the reservoir. Control Ieve'r' 79 is prefsired amount thelever is released and returned toits neutral position closing off the ports leading to

lines

77 and 78 to loclcthe exteusibleconriecting rod'sin a-desired-posi-- manner by,

valves

81 and 82 respectively;

The conveyor 63 is operatedby a, fluid motor 83 which is connected to two-way valve 84 by

lines

85 and 86. The two-way valve operates the same as valve 79 but inasmuch as it is desired that fluid motor 83 operate continuously, there is provided a latch 87 shown in Fig. 1' which will maintain lever 88in either its upper or lowered position against the force of, the spring (not shown)" tending to urge lever 88 toward neutral position. A regulator valve 89 is provided in line 86 and regulates the flow of fluid through fluid motor 83 to thereby regulate the speed of the belt of conveyor 63.

Alike control is provided forthe crowd motor 90 which 7 provides the power for moving the trencher over'the ground during the ditching operation and includes a twoway valve 91 connected with the fluid motor through

lines

92 and 93 and provided with a regulator 94 which regulates the flow of fluid through fluid-motor 9,0 to control the, speed of the vehicle in moving over the ground. A latch 99 (Fig. l) is provided-to hold lever 100 in either upper or lower position to provide for continuous flow through valve 91. A regulator valve assembly 95 which is associated with the bank of valves 75 maintains a back pressure on the system so that the valves may be connected in series and permits the by-pass of excess fluid being delivered to the banko f valves but not being used thereby. In this connection it' is preferable to employ a variable volume. fluid pump 73 so as to reduce the power consumption when a large volume of hydraulic fluid is not needed. 7

To prevent overloading of any part of the hydraulic system, there may be provided relief valve means associated with any of the two-way valves and the mechanism which it controls. Preferably, such relief valve means is associated witheach of the several -conduits by means interior of the bank of valves 75. The principle of such a relief valve is shown in Fig. 8 in connection with two-way valve 76. A relief valve 96b is positioned in a by-pass conduit 97 interconnected between conduit 77 and conduit 74b downstream of valve 76 to regulate flow from conduit 77 to conduit 74b. A similar'valve 96a is positioned in by-pass conduit 97a interconnected between conduit 78 and conduit 74a upstream of valve 76 this arrangement, if the force tending to retract extensible member 37, such as by the application of a force to the bucket line during digging from thestriking of an obstruction of some nature, be of-suflicient magnitude to exceed the setting of relief valves 96a and 96b, then the relief valves would permit the by-pass of fluid into conduit 74b from conduit 97, andinto conduit 78 from conduit 74a to permit connecting rod37 to retract. fThese relief valves may be placed in each of the conduits leading to the two-way valvesas may be desired to prevent overloading of any portion of the hydraulic system and to serve as a safety factor as in the case of the boom cylinders 32 and33. .The construction and operationof the bank of valves 75 including the pressure relief means incorporated into the bank of valvesis well known 'to those skilled in the art and a more detailed discussion will not be given here. i

From the above it will be appreciated that there has been provided a hydraulic control system for controlling the attitude of the bucket line, the'speed of the crowd motor and of the conveyor belt with all of these controls being manipulatedfrom a singl'e pan'elshown generally at98'inFig. 1. v

In connection with the operation of the control panel, there is provided a bucket type seat 136 which may be releasably secured to'the vehicle in a position from which the operator may handle both the steering wheel of the truck and the several controls of the panel.

a J In Fig. '9 there is'shownlthe power transmission'systo regulate flow from conduit 74a intocond'uit 78. With tem for alternately connecting the engine ofthe truck with the drive wheel differential 17 of the vehicle and with the bucket line differential 20, including the gear box 134 formaking such connections, and the fluid pump and crowd motor. The main drive shaft 101 of the gear box is connected to the conventional transmission of the truck by a drive shaft 102. The gear box is provided with a first driven shaft 103 which is connected by a suitable torque tube 104 with the differential 17 of the truck, and a second driven shaft 105 which is connected through a suitable torque tube 106 with the bucket line differential 20. Shaft 101 extends completely through the gear box 134 and is provided with universal joint connections 107 on the end of the shaft removed from the end connected with drive shaft 102. Torque tube 104 may be connected to universal joint part 107 for direct drive through the gear box when the truck is to be moved over long distances. For a short distance, the truck is preferably driven through the drive provided by the gear box with torque tube 104 connected to shaft 103. A chain sprocket 108 is mounted for rotation about shaft 101 and is connected to a chain sprocket 109 which is non-rotatably mounted on shaft 103 by a chain 110 whereby rotation of sprocket 108 will rotate shaft 103 and drive the vehicle along the ground during roading. A second sprocket 111 is mounted for rotation about shaft 101 and is connected to a sprocket 112 non-rotatably mounted upon shaft 105 by a chain 113 whereby rotation of sprocket 111 will drive shaft 105 and operate the bucket line. Sprockets 108 and 111 are provided with confronting jaw clutch parts 11.4 and 115. A main jaw clutch 116 is splined on shaft 101 and provided with jaw clutch parts in its opposed faces for alternate engagement with clutch parts 14 and 115 carried by sprockets 108 and 111, respectively. Thus, movement of clutch 116 into a position to engage clutch 108 will cause sprocket 108 to drive shaft 103 and hence the differential 17. Movement of main jaw clutch 116 into a position to engage sprocket 111 will drive shaft 105 and hence bucket line differential 20. This latter drive provides for a direct mechanical connection between the engine and the bucket line whereby most of the horsepower available from the engine can be applied directly to the bucket line.

A drive for fiuid pump 73 is provided by a sprocket 117 which is also rotatablymounted on main drive shaft 101 and provided with jaw clutch parts 118which are adapted to be engaged by pump clutch 119 which is splined on shaft 101. Sprocket 117 drives a sprocket 120 which is non-rotatably mounted on a shaft 121 through a chain 122. Shaft 121 drivesthe impeller of pump 73 to provide the hydraulic fluid for the hydraulic operating system. Pump 73 should be disconnected during roading of the trencher to prevent driving the pump at too high a speed and to prevent unnecessary wear of the hydraulic system. Trenching is carried out in low gear and hence drive shaft 102 turns much faster during roading than during trenching.

Hydraulic pump 73 drives crowd motor 90 which is selectively connectable with driven shaft 103 by a sprocket 123 which is rotatably mounted upon first driven shaft 103 and is provided with clutch dogs 124 which are adapted to be alternately engaged by the clutch dogs of a crowd clutch 125. Clutch 125 is splined to shaft 103 for selective engagement with sprocket 123. Sprocket 123 is driven by fluid motor 90 through a suitable reduction chain indicated generally at 126. Fluid motor 90 is driven by the hydraulic pump 73 as indicatedin Fig. 7. During roading of the vehicle at which time double-jawed clutch 116 would be in a position to connect driven shaft 103 with main shaft 101, clutch 125 should be disengaged from sprocket 123 so that shaft 103 would not drive fluid motor 90 while the trencher is being transferred between locations.

The gear box 134 should be partially filled with a suite able liquid to provide an oil bath for the moving parts therein.

In order to positively prevent the engagement of crowd clutch and pump clutch 119 while the vehicle is on the road, a system of levers has been provided with stop parts which maintain clutches 119 and 125 in disengaged relationship while main clutch 116 is in roading position. Referring to Fig. 10, it will be noted that each of the clutches is provided with an annular groove to receive the yoke of an operating lever. Main clutch groove 116a receives the yoke of a control member 127 which extends into the truck cab through a suitable linkage and terminates in a lever therein. The groove 119a in pump clutch 119 receives the yoke of a control member 128 which terminates in a lever 129 on the control board 98. Groove 125a of clutch 125 receives the yoke of a control member 130 which terminates in a lever 131 on control panel 98. The

control members

127, 128, and 130 all have portions which move in the same direction and in the same plane.

Members

128 and 130 are provided with dogs 128a and 130a which extend into the path of a dog 127a carried by member 127. The relationship of these three dogs are such that upon moving of main clutch 116 into roading position dog 127a will engage both dog 128a and dog 130a to positively move the pump clutch 119 and the crowd clutch 125 into disengaged positions and to hold them in such positions so long as the main clutch is in roading position. When the main clutch is in its alternate position for driving the bucket line, then control

members

128 and 130 may be operated to selectively engage the crowd motor and to engage the pump by operation of levers 129 and 131.

From the above it will be seen that there has been provided a transmission system which may be utilized to drive the truck over a public highway at normal truck speeds through a mechanical drive or when digging to mechanically connect the engine with the bucket line and drive a fluid pump which operates the hydraulic control system controlling the attitude of the bucket line, such system being entirely controlled from a single panel.

There has been provided a trencher in which the bucket line may be moved into a position to overlie the chassis of a cab and chassis truck with the principal dimension of the bucket line extending horizontal to the earth so as to obtain minimum clearances with the vehicle in roading position, such bucket line being movable into a digging position which may be at any angle in an arc of 90 commencing with the bucket line extending horizontally behind the chassis of the vehicle and extending through a 90 arc to a vertical attitude at the rear of the vehicle. There has also been provided a mounting for such a bucket line which makes possible the use of a radiating arm power take-off, such mounting permitting rotation of the bucket line about its pivotal connection without disassembling any part of the trencher and without jackknifing the jointed-radiating-arm power transmitting means into a position to strike the chassis as the bucket line is moved into its roading position. The trencher is capable of travel at normal truck speed over the highways and of digging both short trenches and trenches of extended distances over flat country or across a slope.

The springs of the truck are protected against overloading and suitable release means are provided to prevent damage to the trencher upon the bucket line striking an obstruction.

By utilizing a standard truck for both the power source and carriage, the original cost of the machine is considerably reduced. Transportation charges and/or investments in separate pieces of equipment for such purposes are, to all practical purposes, entirely eliminated. One man can drive the trencher to the job and operate it, thus saving labor costs. With the full truck speed available the time alone saved in moving the trencher between jobs, as compared with loading and unloading any other trencher on a trailer truck, willmean considera l'yymore profit one'acl'YjoHQ nally, the ea'dyi availability and low" cost of"standaid truck parts win.

It will be, understood that ceitaitiflfe'atures and'sub combinations are of utility'and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims- .v p l As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed l. A bucket line assembly adapted to be mounted on a cab and chassis truck, comprising, a shaft adapted to be driven by the truck motor and journaled for rotation about an axis extending transversely of the truck adjacent its rear end, a bucket line carrier mounted for swinging movement about said axis from a position overlying the chassis for roading to a raised position for digging, a bucket line, means mounting the bucket line on the carrier for movement therealong to extend a portion of the bucket line beyond the carrier for digging and to retract the bucket line for roading, and means connecting the shaft to the bucket line to operate the bucket line in any desired digging angle and at any depth.

2. A bucket line assembly adapted to be mounted on a cab and chassis truck, comprising, a shaft adapted to be driven by the truck engine and journaled for rotation about an axis extending transversely of the truck adjacent its rear end, a flat elongate carrier pivoted adjacent one of its ends for swinging movement about said axis from a substantially horizontal position overlying the chassis of the truck for roading to a digging position at the rear of the truck, guideway means extending along the length dimension of the carrier, a bucket line, slide means carried by the bucket line and coacting with said carrier guideway means for mounting the bucket line for movement along the carrier, and jointed-radiating-arm power transmitting means interconnecting said shaft and bucket line to operate the bucket line at any selected digging angle and at any selected depth.

3. A bucket line assembly adapted to be mounted on a cab and chassis truck, comprising, a shaft adapted to be driven by the truck engine and journaled for rotation about an axis extending transversely of the truck adjacent its rear end, a bucket line carrier mounted for swinging movement about said axis between a position overlying the chassis for roading and a raised position for digging, means for swinging the bucket line carrier about said axis and holding it in any desired angular position, means rendering ineffective said swinging and holding means upon the application of a predetermined torque to the bucket line carrier to permit the carrier to swing about said axis, a bucket line mounted for movement along said carrier to extend a portion of the bucket line beyond the carrier for digging and to retract the bucket line for roading, and drive means connecting the shaft to the bucket line in every digging angle and depth.

4. A transmission system for a trencher comprising, a main shaft connectable with the prime mover of the trencher, first and second toothed wheels provided with clutch parts and journaled on the main shaft for driving respectively a first driven shaft to operate the driving wheels of the trencher and a second driven shaft to operate the bucket line of the trencher, a clutch splined on the main shaft and alternately engageable with the clutch parts of the first toothed wheel for moving the trencher alongv the v ground-and the clutch parts oft the; second toothed wheel fortdriving the bucket line, alfluidpump, means selectively connecting the main shaft to the fluid pump to drive same, a third toothed wheel provided with clutch parts andjournaled on vthe first driven shaft, a crowd motor operated by said pump for rotating the third toothed wheel, and a clutch splined on the first driven shaft and selectively engageable with clutch, parts of the-third toothed wheel to drive the first driven shaft and-move the trencher along thegroundwith the? crowd motor.

5. A trencher comprising, in combination, a cabv and chassis truck, a shaft adapted. to be driven by the truck motor and journaled for rotation about an axis extending transversely of the truck adjacent its rear end, a bucket line carrier mounted for swinging movement about said axis from a position overlying the chassis for roading to a raised position for digging, a bucket line, means mounting the bucket line on the carrier for movement therealong to extend a portion of the bucket line beyond the carrier for digging and to retract the bucket line for roading, means connecting the shaft to the bucket line to operate the bucket line in any desired digging angle and at any depth, leveling jacks for tilting the chassis of the trencher relative to the ground, a conveyer belt for receiving dirt from the trencher, and a hydraulic control system operable from a single panel for controlling the digging operations other than the speed of the bucket line comprising, a closed hydraulic circuit including a reservoir of hydraulic fluid and a pump operated by the truck engine for circulating fluid in the system, a plurality of valves operable from said panel each controlling flow of hydraulic fluid therethrough for respectively swinging the carrier about its mounting in either direction, for raising and lowering the bucket line, for tilting the chassis of the trencher, for driving the conveyer belt in either direction and for driving in either direction a crowd motor which drives the trencher over the ground during digging.

6. A transmission system for a trencher comprising, a main drive shaft connectable with the prime mover of the trencher, a first driven shaft, a drive shaft connnecting the drive wheels to the first driven shaft, a second driven shaft connected to the bucket line of the trencher, means alternately connecting the main drive shaft to either the first or second driven shafts to drive the trencher along the ground or to operate the bucket line respectively, a fluid pump, means for selectively connecting the prime mover of the trencher to the fluid pump to drive the pump, a crowd motor operated by the fluid pump, means for selectively connecting the crowd motor to the first driven shaft to drive the trencher along the ground, and means for connecting the drive shaft in direct drive with the main shaft, whereby the drive shaft may be disconnected from the first driven shaft and connected with the main shaft for long distance roading of the trencher.

7. A transmission system for a trencher comprising, a main drive shaft connectable with the prime mover of the trencher, a first driven shaft connected to the drive wheels of the trencher, a second driven shaft connected to the bucket line of the trencher, means alternately connecting the main drive shaft to either the first or the second driven shafts to drive the trencher along the ground or to operate the bucket line respectively, a fluid pump, means for selectively connecting the prime mover of the trencher to the fluid pump to drive the pump, a crowd motor operated by the fluid pump, means for selectively connecting the crowd motor to the first driven shaft to drive the trencher along the ground, a system of members controlling the several connecting means, and stop parts on the member controlling the alternative connection of the main shaft to the driven shafts cooperable with stop parts on the other control members to prevent the connection of the prime mover to the fluid pump or the crowd motor to the first driven shaft while the main drive shaft is connected to the first driven shaft.

References Cited in the file of this patent UNITED STATES PATENTS Brown 1- Aug. 15, 1905 Otto July 24, 1923 Barber June 10, 1930 Barber Mar. 10, 1931 Pavlik Mar. 22, 1932 Hanlon May 31, 1932 Hollmann et a1 Feb. 23, 1943 16 Strain Dec. 21, 1943 Briscoe Dec. 19, 1944 Brown Nov. 12, 1946 Everett Nov. 11, 1952 Thomas Apr. 28, 1953 Bennett June 9, 1953 Askue Aug. 11, 1953 Banister June 19, 1956 Burns et a1 Mar. 5, 1957 FOREIGN PATENTS Germany June 25, 1916 Great Britain May 28, 1934