US3108387A - Excavating machine - Google Patents

Description

Oct. 29, 1963 v. s. PENOTE EXCAVATING MACHINE 2 Sheets-Sheet 1 Filed Nov. 6, 1961 INVENTOR. ViNceu'r S. PENOTE 75w, $130 Te ll TT N zys Oct. 29, 1963 v. s. PENOTE 3,108,387

EXCAVATING MACHINE Filed Nov. 6, 1961 2 Sheets-Sheet 2 CONTROL VR LVE BHNK j 4 4 INVENTOR.

VI'NCENT S. PENOTE BY 275m 351 1 TM I nrromsys United States Patent Ofiice 3,168,337 EXCAVATING MACHENE Vincent S. Penote, Shaker Heights, Ohio, assignor to The Cleveland Trencher Company, Cleveland, Ohio, a corporation of Ohio Filed Nov. 6, 1961, Ser. No. 150,359 6 Claims. (Cl. 379()) This invention relates in general to excavating machines, and more particularly to a digging line tensioning device for excavating machines.

In the pending United States patent application of Vincent S. Penote and Henry L. Meyer, Serial No. 94,025, filed March 7, 1961, there is disclosed an excavating machine comprising a generally horizontally extending boom with a bucket equipped endless digging line movably mounted on the boom by means of spaced rotatable means, including wheeled trucks, supported by the boom. It has been found that during excavating operations, sometimes a rock or other obstruction becomes lodged between the digging line and the rotatable means or wheels, which causes an increased tensioning of the digging line, and may stall the digging unit, or even cause failure of the digging line chain.

The present invention provides a novel digging line tensioning mechanism which is operative to maintain the digging line under a predetermined tension during normal operation of the excavating machine, but which includes means for automatic release of the tension when the tension in the digging line exceeds a predetermined amount, such as may occur when a rock or the like becomes wedged between the wheeled trucks of the digging unit and the digging line.

Accordin ly, an object of the invention is to provide a novel chain tensioning device for an endless digging line of an excavating machine.

Another object of the invention is to provide a fluid powered tensioning device, for use with the digging line of an excavating machine, which device is operable to effectively tension the digging line, but which includes means for releasing the tension, when the latter exceeds a predetermined maximum.

Another object of the invention is to provide a novel tension ng device for the digging line of an excavating machine which device is rugged in construction, and which may be readily applied to existing excavating mas chines, or which can be conveniently embodied in new excavating machines.

A still further object of the invention is to provide an excavating machine having an endless bucket equipped digging line mounted on the machine by means of rotatable members, and including a .tensioning device coacting with the rotatable members for maintaining a predetermined tension in the digging line.

A still further object of the invention is to provide a fluid powered system for a tensioning device for the digging line of an excavating machine, which may be readily coupled to an existing lluid powered system of an excavating machine, for operating the tensioning device.

Other objects and advantages of the invention will be apparent from the foregoing description taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a side elevational, partially broken, generally diagrammatic view of an excavating machine embodying the tensioning device of the invention;

FIG. 2 is enlarged, fragmentary, side elevational View of the tensioning device of FIG. 1;

FIG. 3 is a sectional view taken generally along the plane of line 33 of FIG. 2, looking in the direction of the arrows;

FIG. 4 is a schematic showing of a fluid system which Patented Get. 29, 1%63 2 may be expeditiously utilized for actuating the tensioning device of the invention, and which may be readily coupled into an existing fluid system conventionally utilized on excavating machines.

Referring now again to the drawings, and in panticular to FIG. 1 thereof, there is illustrated an excavating machine embodying the instant invention. Such an excavating or trenching machine broadly comprises a main frame 10 supported on suitable tractor treads 12, a main power plant or internal combustion engine '14 supported on the forward end of the frame 10, a structure 16 for supporting a vertically movable boom 18 mounted adjacent the opposite end of the vehicle chassis, and an endless bucket equipped digging unit 20 movably mounted on the boom structure and drivingly connected to the motor unit 14 of the machine. The digging line 22 of such digging unit 20 is conventionally formed from endless stretches of transversely disposed chain links which support the buckets 24 thereon, and with such digging lines being movably mounted on rotatable members including wheeled trucks 26, 26a supported by the boom 18. The digging unit may be of the generally inverted triangular shaped configuration in side elevation illustrated, and may be driven by drive drum 28.

Transversely spaced wheels 32 of truck 26a may be rotatably mounted on a shaft 36 extending transversely of the boom 18, with the shaft being mounted adjacent its ends in bearing blocks 38 mounted in elongated slots 49 in transversely spaced housing or bracket members 42, secured to the corresponding end of the boom structure 18.

Referring now to FIG. 3, each of said bearing blocks 33 preferably embodies flange means 44 thereon which overlap confronting portions of the associated housing 42, and thereby are retained in alignment in said housing, but are permitted reciprocal movement in the housing. A fluid powered ram 48 is secured at one end, such as 50, to the boom structure 18, and with the other end, such as the outer end of the piston rod, being attached to the corresponding bearing block member 38.

Hydraulic or fluid powered systems are conventionally utilized on excavating machines in present day practice, to actuate various components of the machines, such as for instance, the unloading conveyor mechanism 52, both for driving the conveyor and for shifting it transversely of the machine and through the digging unit, and thus there may be conventionally provided a source of pressurized fluid in conjunction with the excavating machine. The present digging line tensioning device can be expeditiously installed in the conventional system, and as shown for instance in FIG. 4, wherein a pump 53 represents a source of pressurized fluid, say for instance, at 2000 pounds per square inch pressure, and directs the pressurized fluid via line 54 to a valve bank mechanism 56 for controlling and actuating the various aforementioned fluid powered actuated components of the machine. Pump 53 may be driven from power plant 14 on the machine. A line 58 is taken off of supply line 54 to the valve bank, and may be provided with a manually controlled valve '60 for controlling the flow of fluid therethrough. A check valve 62 is provided for preventing reverse flow of fluid in line 58, and the latter is coupled to the cylinders of the aforementioned rams 48 in parallel operating relation. A line 64 may also be provided with a manually operated control valve 68, and a gauge member 70 may be provided for indicating the pressure in line 64. A pressure relief valve 72 which may be adjustable and set for instance to open at 2500 pounds per square inch, is provided in line 64 after gauge 70, with line 64 then communicating with a reservoir 74.

During operation of the excavating machine, pressurized fluid will ordinarily be supplied to the ram members 48, thereby applying pressure to the bearing blocks 38 mounting the truck wheels 32, and thus applying a predetermined tension to the digging line 22 of the digging unit of the machine. In the event that a rock or some other obstacle becomes lodged between the chain of the digging line and the means mounting the digging line on the machine, the pressure in the fluid distributing lines 58, 64- will rapidly increase, and the relief valve 72 will open to relieve such pressure by slackening up on the chain and thus preventing damage to the digging line, as well as preventing stalling of the digging unit. During such release of excessive pressure, the obstacle may dislodge itself and thereby permit the automatic closing of the relief valve, or the machine operator can stop the machine and manually remove the obstacle when he notices the pressure indicated by gauge 70 as exceeding a predetermined amount. The manual control valves 69, 68 are provided for deactivating all or part of the system by either cutting off the system entirely from the supply of pressurized fluid or by cutting off the relief valve section of the system.

It will be noted that the respective bearing block and associated ram is disposed at an angular relationship with respect to the boom, and so disposed as to apply a force that will be directed both upwardly and rearwardly with respect to the horizontal, and not strictly parallel to the rear stretch 82 of the digging line, so that tension is etfectively applied both to the horizontal stretch 84 of the digging line chain as well as to the generally vertically extending stretches of chain.

From the foregoing discussion and accompanying drawings, it will be seen that the invention provides a novel tensioning device for the digging line of an endless digging unit, and wherein the device is operable to automatically release the pressure, if the latter builds up beyond a predetermined maximum, so that stalling of the digging unit and/ or breakage of the digging line will not occur. The invention also provides a fluid powered tensioning mechanism which can readily be incorporated into existing machines, or which may be embodied in new machines.

The terms and expressions which have been utilized are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of any of the features shown or described, or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.

I claim:

1. In a mobile trenching machine including a generally horizontally extending boom, means depending from said boom, first rotatable means mounted adjacent the lower end of said depending means, second rotatable means rotatably mounted on said boom forwardly of said first rotatable means, third rotatable means mounted on said boom in rearwardly spaced relation to said second rotatable means, an endless digging line strung about said rotatable means and adapted to be driven by one of said rotatable means, said digging line defining a generally inverted triangular shape configuration in side elevation, means including transversely spaced bearing blocks adjustably mounting said third rotatable means on said boom, said boom including transversely disposed guideways therein, extending diagonally upwardly and rearwardly with respect to said boom, each of said guideways receiving in movable relation an associated one of said bearing blocks therein, and fluid actuated means coacting with said bearing blocks to maintain a predetermined tension in said line, said fluid actuated means extending in a like diagonal direction as said guideways and with respect to said boom, said guideways diverging in a downward direction with respect to the rear stretch of said digging line.

2. A trenching machine in accordance with claim 1, wherein said bearing blocks include means thereon for guiding the bearing blocks in their movement lengthwise of said guideways.

3. In a mobile trenching machine including a generally horizontally extending boom, an endless digging unit supported rearwardly of said trenching machine adjacent one end of said boom, a plurality of spaced rotatable means mounted on said boom, an endless digging line strung about said rotatable means and adapted to be driven by one of said rotatable means, said digging line including a generally horizontally extending stretch and a pair of generally vertically extending stretches extending downwardly toward one another from said horizontally extending stretch defining a generally inverted triangular shaped configuration in side elevation, adjustable bearing means mounting the rearwardmost of said rotatable means on said boom, hydraulic ram means coacting with said adjustable bearing means and extending diagonally upwardly and rearwardly from said boom generally intermediate said horizontally extending stretch and the rearwardmost of the associated one of said vertically extending stretches, and fluid control means operably coacting with said ram means for selectively maintaining a predetermined tension in said horizontal and vertically extending stretches and for automatically releasing tension from said stretches when the tension in the digging line exceeds a predetermined value.

4. A trenching machine in accordance with claim 3, wherein said fiuid control means includes a fiuid distributing line connected to said ram means adapted for connection to a source of pressurized fluid, a check valve in said fiuid distributing line for preventing reverse flow of fluid from said ram means, and relief valve means disposed intermediate said check valve and said ram means for limiting the maximum fluid pressure that may be applied in said fluid distributing line.

5. A trenching machine device in accordance with claim 4 including a manually operated control valve disposed intermediate said relief valve means and said ram means for deactivating said relief valve means.

6. A trenching machine device in accordance with claim 4 wherein a pressure indicating gauge member is disposed in said distributing line intermediate said ram means and said relief valve means.

References Cited in the file of this patent UNITED STATES PATENTS 794,624 Hoadley July 11, 1905 2,782,534 Wall Feb. 26, 1957 2,818,311 Ashley Dec. 31, 1957 2,998,998 Hyler et al Sept. 5, 1961 FOREIGN PATENTS 1,095,681 Germany Dec. 22, 1960

Claims (1)

1. IN A MOBILE TRENCHING MACHINE INCLUDING A GENERALLY HORIZONTALLY EXTENDING BOOM, MEANS DEPENDING FROM SAID BOOM, FIRST ROTATABLE MEANS MOUNTED ADJACENT THE LOWER END OF SAID DEPENDING MEANS, SECOND ROTATBLE MEANS ROTATABLY MOUNTED ON SAID BOOM FORWARDLY OF SAID ROTATABLE MEANS, THIRD ROTATABLE MEANS MOUNTED ON SAID BOOM IN REARWARDLY SPACED RELATION TO SAID SECOND ROTATABLE MEANS, AN ENDLESS DIGGING LINE STRUNG ABOUT SAID ROTATABLE MEANS AND ADAPTED TO BE DRIVEN BY ONE OF SAID ROTATABLE MEANS, SAID DIGGING LINE DEFINING A GENERALLY INVERTED TRIANGULAR SHAPE CONFIGURATION IN SIDE ELEVATION, MEANS INCLUDING TRANSVERSELY SPACED BEARING BLOCKS ADJUSTABLY MOUNTED SAID THIRD ROTATABLE MEANS ON SAID BOOM, SAID BOOM INCLUDING TRANSVERSELY DISPOSED GUIDEWAYS THEREIN, EXTENDING DIAGONALLY UPWARDLY AND REARWARDLY WITH RESPECT TO SAID BOOM, EACH OF SAID GUIDEWAYS RECEIVING IN MOVABLE RELATION AN ASSOCIATED ONE OF SAID BEARING BLOCKS THEREIN, AND FLUID ACTUATED MEANS COACTING WITH SAID BEARING BLOCKS TO MAINTAIN A PREDETERMINED TENSION IN SAID LINE, SAID FLUID ACTUATED MEANS EXTENDING IN A LIKE DIAGONAL DIRECTION AS SAID GUIDEWAYS AND WITH RESPECT TO SAID BOOM, SAID GUIDEWAYS DIVERGING IN A DOWNWARD DIRECTION WITH RESPECT TO THE REAR STRETCH OF SAID DIGGING LINE.

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