US2705611A - Cable controls - Google Patents

Description

April 5, 1955 F. FALKNER CABLE CONTROLS Filed Feb. 23, 1949 3 Sheets-Sheet l i in /Nl/EN7'OR FREDERICK FALKNER ATTORNEYS April 5, 1955 F. FAI. KNER 22705311 CABLE CONTROLS 0 Filed Feb. 23, 1949 3 Sheets-Sheet 5 INVENTOR FREDERICK MAI/V0? ATTORNEYS United States Patent 1 2,705,611 CABLE coNTRoLs Frederick Falkner, Los Angeles, Calif.

Application February 23, 1949, Serial No. 77,828

8 Claims. (Cl. 254-172) This invention relates to cable controls, and more specifically contemplates actuating mechanism for the dipper trip of gas or diesel shovels and drag line tensioning devices for mechanical buckets, magnets and the like.

Dippers of large power-driven shovels of the prior art are usually provided with a hinged bottom normally latched in closed position and adapted to be opened in response to gravity incident to tripping the latch. The conventional latch is of a self-locking type, and its release is effected by the operator from the platform of the shovel by the application of considerable tension to a cable connected thereto. The cable is accordingly preferably secured to a power unit through which the required tension thereto can be effectively applied and relieved. As the speed at which the shovel can be operated depends largely upon the sensitivity of the latch control assembly, it is desirable that the cable be held free from slack at all times so that only slight additional tension, in response to actuation of the power unit, is required to trip the latch. The continuous movement of the dipper during operation necessitates the automatic reeling and unreeling of the cable by the power unit to compensate for variations in its effective length in order to maintain uniform tension of a degree only slightly less than that required to trip the latch.

It is common practice, and in most cases a necessity, to equip mechanical buckets of the type adapted for suspension by cables from a crane or the like with a drag line to prevent undesirable turning of the bucket as it is raised and lowered, and to assist in maintaining control of the same while it is moved laterally. In accordance therewith, mechanism is provided to maintain a uniform predetermined tension upon a cable attached to one side of the bucket. Various devices, such for example as counterweights and spring mechanism, have heretofore been employed for this purpose. However, such equipment is incapable of facile, critical adjustment, does not possess the requisite flexibility, and in many cases, particularly where springs are employed, cannot maintain a uniform tension throughout an extended range of movement of the bucket in operation.

It is, therefore, a principal object of the present invention to provide a tensioning device for cables adapted for use as a tripping expedient or drag line, embodying a pulley and a brake assembly coaxially aligned and operatively associated through an arrangement of gears forming an epicyclic train elfective to variously divide power applied thereto between the brake drum and pulley in proportion to the degree of braking of the drum.

Another object is the provision of a latch releasable in response to tension upon a cable attached thereto in combination with the remote control therefor comprising a spool for the cable rotatable under compulsion of a constant driving force of maximum power normally less than that required to trip the latch, but capable of being varied to, selectively, reel the cable and thereby trip the latch or release the cable to the exact degree required to compensate for changes in the distance between the spool and latch mechanism during operation of the apparatus controlled by the latter.

Another object is to provide a pulley and brake drum .driven through differential gears in combination with means to engage the drum and impose a frictional resistance to rotation thereon of predetermined degree so as to correspondingly increase the rotative urge of the pulley to an extent suflicient to maintain a cable conice nected to the pulley for spooling, under constant tension less than that required to actuate mechanism controlled by the cable, the frictional drag upon the pulley being variable to facilitate adaptation of the unit to different requirements.

Still another object is the provision of a drag line tensioning device comprising a pulley upon which the line may be reeled, and embodying a manual control for determining the degree of unrestrained extension of the line and for regulating restraint upon the unreeling of the line imposed by resilient means selectively operable to maintain, throughout a variable but predetermined degree of extension of the line from the pulley, a resilient tension upon the latter so as to permit withdrawal of a selected reach of the line from the pulley and thereafter, upon the relief of working tension, to compel the return of the selected section of the line, withdrawn in response to the working tension, to the pulley.

Numerous other objects, such for example as simplicity of construction, ease of operation and control, facility of assembly, susceptibility to modification for adaptation to numerous types of equipment, and durability will be apparent to those of skill in the art upon examination of the following description read in the light of the accompanying drawings, in which:

Fig. l is a side elevation of a mechanical shovel illustrating my invention in operative association therewith for controlling actuation of the latch mechanism of the dipper;

Fig. 2 is a plan view of the control unit on line 22 of Fig. 1 embodying principal features of my invention;

Fig. 3 is an enlarged sectional view on line 33 of Fig. 2, illustrating the internal construction;

Figs. 4 and 5 are transverse sectional views taken on correspondingly-numbered lines of Fig. 3;

Fig. 6 is a vertical longitudinal section through a modified form of my invention;

Fig. 7 is a transverse section taken on line 77 of Fig. 6.

Referring to the drawings more in detail, the numerals of which indicate similar parts throughout the several views, 10 designates generally a mobile mechanical shovel of a type well known in the art comprising generally a rotatable platform 11 .mounted upon tracks 12 and forming a base for one end of a boom 13 intermediate the ends of which a dipper arm 14 is operatively supported. As in accordance with conventional constructions, the rearward end of arm 14 is reciprocably supported and actuated through mechanism, generally indicated by numeral 15, carried intermediate the ends of boom 13 whereby the dipper 16 may be raised and lowered, and retracted and extended. A cable 17, having one end secured to dipper 16, passes over pulley 18 journalled at the upper end of boom 13 and extends to a drum 19 located above the platform 11. Drum 19 is rotated through clutch mechanism (not shown) controlled by the operator by a gear 20 driven continuously while the shovel is in use so as to spool and unreel cable 17 as required for manipulation of the dipper.

The dipper 16 is equipped with the usual hinged bottom 21 through which material scooped into the dipper through the forward upper end thereof may be discharged. Bottom 21 is supported by a pair of reinforcing bars 22, hinged on a pin 23 to the adjacent end of arm 14 whereby the bottom may be swung from open to closed position in an are having its center on the axis of pin 23. A con ventional latch (not shown) is provided to releasably secure bottom 21 of the dipper in closed position, which is released by a link 24 connected at its rearward end to a lever 25 depending pivotally from arm 14 adjacent the back of dipper 16. It will be observed that the latch may be released by swinging lever 25 rearwardly, and to this end a cable 26 is connected to the lower end of the lever. Cable 26 extends through fairleads 27 suspended from the mechanism 15 by which arm 14 is reciprocably supported, and thence through suitable pulley guides 28 carried by the upper part of the frame of the platform 11 to the control unit embodying the essential features of my invention.

The control unit proper comprises a base 29 upon which two standards 30 and 31 are mounted in spaced relation. Between the standards a gear housing 32, comprising two complementary sections 33, is disposed, oppositely projecting ends of the respective sections 33 being journalled in coaxially aligned bearings in the respective standards 30 and 31. A third standard 34 is mounted upon base 29 in spaced relation and in alignment with the standards 30-31 for the rotatable support of one end of a spool shaft 35. Shaft 35 projects through the nearest adjacent standard 31 and is freely rotatable in the end of the gear housing section 33 journalled in the said standard. A spool 36, mounted upon shaft 35 so as to rotate therewith, is housed within a stationary guard 37, encircling the peripheries of the spool flanges 38 to standard 31 and having a central opening therethrough. The guard 37 is formed with a central hub 39 suitably secured in contiguous relation with standard 31, the shaft 35 projecting rotatably therethrough. The stationary position of guard 37 is reinforced by a stud 40, integral with the lower part of standard 31 and to which the corresponding adjacent surface of guard 37 is attached by suitable means.

A brake shaft 41 projects rotatably through the section 33 of the opposite half of the gear housing 32 that is journalled in standard 30, thus being supported in coaxial alignment with shaft 35. The outer end of shaft 41 is reduced in diameter forming a shoulder 42 against which an internal hub 43 of a brake drum 44 is clamped bv a nut 45 threaded on the outer end of shaft 41, whereby drum 44 is rotatable with the shaft. A disk 46, encircling shaft 41, is accommodated within and covers the open end of drum 44, and is equipped with a hub 47 attached to the adjacent standard 30. Disk 46 is accordingly stationary, and is reinforced by means of a pin 48 integral with the standard 30 and having an extension 49 of reduced diameter projecting through disk 46 into the drum. Arcuate internal expanding brake shoes 50 are pivotally mounted on extension 49 of pin 48 within brake drum 44 so as to extend in close proximity to the internal surface of the drum to a point adjacent the upper are of the latter. The upper ends of the respective shoes 50 are turned inwardly as at 51 to form bearing surfaces for a cam 52 mounted on a short shaft 53 extending laterally through the disk 46. The cam 52, which is generally elliptical in form and normally vertically arranged, is operable in response to turning of shaft 53 to spread-the upper ends 51 of shoes 51 apart and urge the brake bands 54, riveted to the surface of the respective shoes, into contact with drum 44 in accordance with the operation of conventional internal brakes. To facilitate this manipulation of shaft 53 and the brake, a lever 55 is attached to the external end of the shaft.

The ends of the respective shafts 35 and 41 projecting into the gear housing 32 from opposite ends thereof are each equipped with a bevel gear 56. Gears 56, which are of identical construction, are splined or otherwise nonrotatably attached to the respective shafts 35 and 41, and are disposed in spaced relation offset slightly from the center of gear housing 32 with the teeth thereof projecting toward one another. Interposed between the gears 56 is a spider 57 comprising three spindles 58 extending radially outward and equi-spaced apart circumferentially, their outer ends being accommodated in bearings formed by complementary contiguous parts of the respective halves 33 of the gear housing 32. A differential gear 59 is freely rotatable on each spindle 58 with its teeth operatively engaged with both bevel gears 56.

As hereinabove indicated, the gear housing 32 is journalled in respective standards 30 and 31 and receives rotative impetus through a driving gear 60 welded or otherwise rigidly mounted to the gear housing. The unit is mounted above platform 11 of shovel adjacent cable drum 13 with the driving gear 6% in mesh with the drum gear 29 whereby thelatter is continuously rotated during operation of the shovel so as to impart rotative driving force to either the brake drum 44 or spool 36 or both. A portion of guard 37 is cut away as at 61 for the projection thereinto of cable 26 which is attached to the spool 36 in a manner which assures the reeling of the cable upon rotation of the spool in the direction in which it is driven by the gear mechanism immediately hereinabove described.

The operation of the apparatus is further briefly described as follows: The latch, adapted for actuation by tension upon cable 26, is of a type adapted and is adjusted to withstand considerable tension before disengaging the bottom 21 of dipper 16. This permits cable 26 to be initially drawn taut without releasing the latch. With the mechanism so adjusted, slight additional tension is sufficient to dislodge the latch. It will be appreciated that the rotative force applied to the gear housing 32 through the driving gear 60 will be transmitted to one or the other or both of the shafts 35 and 41, and in the absence of any restraint upon either the spool 36 or brake drum 44 the rotative movement of both of the latter will be substantially the same. However, with the cable attached to spool 36, the latter will not freely revolve even to a degree sufficient to take up the slack in the cable. In such case, the differential gears 59 ride around the bevel gear 56 attached to shaft 35 carrying spool 36 and transmit the entire rotative force to the brake drum 44 through shaft 41. In order, therefore, to compel spool 36 to rotate to a sufficient extent to take up the slack in cable 26, the brake shoes 50 are adjusted by manipulation of the lever 55 and cam 52 to partially restrain rotation of the brake drum. When the frictional drag upon brake drum 44, incident to the adjustment of cam 52, begins to exceed the resistance to rotation of the spool, part of the rotative driving force transmitted through gear 60 will be imparted to the spool. As the slack in cable 26 is taken up in response to this movement of spool 36, the resistance to rotation of the spool is progressively increased so as to compel a correction of the distribution of the rotative driving force between the spool and brake drum through the differential gears 59. It will thus be appreciated that by proper adjustment of cam-controlled brake shoes 50, the frictional drag upon the drum 44 may be fixed at that which is sufficient to assure rotation of spool 36 and reeling of the cable until the tension of the cable almost reaches that which is sufficient to release the latch. This tension can be maintained by producing a resistance to rotation of the drum 44 through the adjustment of the brake shoes 50 that is only slightly less than the resistance of spool 36 to rotation as determined by such tension.

Accordingly, any desired degree of tension may be imparted to cable 26 and maintained continuously. When it is necessary to release the latch, the operator needs only to increase the braking action upon drum 44 so as to direct a greater proportion of the driving force to spool 36 and thereby increase the tension upon the cable to an extent sufficient to overcome the resistance of the latch to disengagement of the bottom 21 of the dipper.

The dipper bottom 21 may again be closed in the usual manner after releasing the brake to relieve all tension upon cable 26. After engagement of the latch, the tension of the cable is then re-established in the manner above described to that slightly less than required for actuation of the latch, whereby the mechanism is in a condition for instantaneous release of the latch upon the application of slight additional braking action to drum 44.

Any remote control for the brake adjustment may be provided, as for example an upstanding brake lever 62, shown in dotted lines in Fig. 1, adapted to be connected to lever 55 by any well-known expedient.

In Figs. 6 and 7 I have illustrated a modified form of the apparatus hereinabove described, which is adapted particularly for utility as a drag line or line-tensioning expedient. pulley, gear and brake assemblies of the embodiment of Fig. l, and as these mechanisms are identical to those of the form of the invention first above described, the description thereof is not repeated. Being adapted for utility as a drag line, the driving gear 60 is omitted.

In the embodiments of Figs. 6 and 7, two standards 63 and 64 are employed in which the axially-aligned hubs 65, respectively, of a gear housing 66 are journalled. A brake shaft 67 and a spool shaft 68 are journalled in the respective bores of the hubs 65, so as to project in coaxial alignment from opposite sides of the gear housing 66, and have keyed thereto a brake drum 69 and a spool 70, respectively. Bevel gears 56, similarly keyed to the shafts 67 and 68, respectively, within the gear housing 66 are in mesh with a pair of differential gears 71, journalled on a transverse shaft 72 having its ends mounted in diametrically opposite sides of the gear housing. The internal expanding brake mechanism of conventional construction, as hereinabove described with reference to the embodiments of Figs. '1 to 5, inclusive, is adapted to be The unit of Figs. 6 and 7 incorporates the V operated by a handle 73 so as to actuate the brake and thereby retard or stop rotative movement of the shaft 67. Integral with the brake drum 69 is a flanged spool 74 for a line 75 by which the drum and shaft 67 may be turned or its rotation controlled as is hereinafter more in detail described.

76 indicates each of the pair of tubular bushings lining the bores of the respective standards 63 and 64 at opposite sides of the gear housing 66 to facilitate relative rotative movement of housing 66 in response to relative rotation between the spool 70 and brake drum 69, in accordance with the operation of the unit as hereinafter described.

The spool 70 is encircled by a guard 77 having a slot or opening 78 in its periphery for extension of a drag line 79 having its inner end attached by suitable means to the spool 70. The guard 77 is secured on the adjacent standard 64 by a set-screw 80, which, when loosened, permits rotative adjustment of the guard 77 depending upon the desired direction of extension of the drag line 79 from the spool 70 to the point of use.

A spring housing 81 having one removable side 82 secured to the body of the housing standard 64 by screws 83, encircles and encloses the gear housing 66. The gear and spring housings 66 and 81 are relatively rotatable, the latter being secured against rotation to the standard 64 by screws 84. The annular chamber 85 formed around the gear housing by the spring housing 81 accommodates a coil spring 86 by which the rotation of the gear housing 66 in one direction is resiliently resisted and limited. The inner end of the spring 86 is bent radially inward as at 87 for projecton into a slot in the gear housing (Fig. 6), while the outer end of the spring 86 is similarly engaged in a slot in the periphery of the spring housing, as indicated at 88.

The operation of the apparatus of Figs. 6 and 7 is briefly as follows: With the brake released, the line 79 may be withdrawn from the spool 70 to any desired extent without tensioning the spring 76. The tension upon the line 79 rotates the spool shaft 68 and connected bevel gear 56 with the spring 86 imposing a resilient resistance to rotation upon the gear housing 66. The turning of the bevel gear 56 referred to, merely rotates the differential gears 71 without turning the gear housing 66, and this motion is accordingly transmitted to the brake drum 69. With the minimum, extended operating length of the line 79 thus determined, the brake is applied so as to thereafter prevent withdrawal of the drag line 79 without, to a corresponding extent, winding the spring 86 more tightly upon the gear housing 66. If the brake is locked so as to positively prevent rotation of the drum 69 and bevel gear 56 with which the drum is connected, the motion of the other gear 56 incident to withdrawal of the line 79 from the spool 70 is limited by the spring 86, and upon relief of working tension upon the line 79, the latter will be partially returned to the spool 70 in response to rotation of the latter by the spring through the gear housing 66, gears 71 and 56 and shaft 68. Thus the rotation of the spool 70, incident to unreeling of the line, is opposed by the tension of the spring 86 and the independent frictional resistance of the brake shoes 50 upon the drum 69. With the brake fully applied, the spring 86 is fully effective. By varying the application of the brake, the effective resistance of the spring 86 to unreeling of the line is correspondingly variably regulated.

It will thus be seen that the line 79 may be extended from the spool 70 to any desired extent without materially affecting the tension of spring 86, and thereafter by application of the brake, imposing a normally progressively greater but variable resistance to further withdrawal of the line. Accordingly, the unit may be installed at any desired distance from the device which the drag line 79 is to control. Moreover, the resilient resistance afforded by the drag line to inadvertent displacement of the work in accordance with the normal operation of my invention is equally applicable to the control of apparatus which is adapted to move through a line of travel longer than the length of the resiliently controlled reach of the line which may be extended from the control unit.

While I have shown and described but two embodiments of my invention, it will be appreciated that numerous changes in design, shape, number and proportion of the parts may be made, and that the particular appli cation of the assembly to a mechanical shovel is only illustrative of a number of different types of equipment utilizing either a drag or trip line to which my invention is equally adaptable, without departing from the scope of my invention, as defined by the appended claims.

What I claim and desire to secure by Letters Patent is:

1. In line-tensioning mechanism, a pair of shafts, a line spool carried by one of said shafts, a load-engaging line connected to and reeled upon said spool, brake mechanism carried by the other of said shafts,and means to rotate said shafts at different speeds variable with the application of said brake and the tension applied to said line, and means to resiliently tension said line.

2. In line-tensioning mechanism, a pair of shafts, a line spool carried by one of said shafts, a load-engaging line connected to and reeled upon said spool, brake mechanism carried by the other of said shafts comprising a brake drum and brake shoe, a lever for manually shifting said brake shoe into contact with said drum, and means to rotate said line spool shaft at: different speeds variable with the actuation of said lever and the tension applied to said line, and resilient means to tension said line.

3. In line-tensioning mechanism, a pair of shafts, a pair of line spools carried by said shafts, respectively, a pair of lines connected to and reeled upon said spools respectively, a differential gear train operatively interposed between said shafts, whereby tension upon one of said lines in excess of tension upon the other of said lines is effective to reel the latter line upon its spool, and resilient means to resiliently tension one of said lines.

4. In linetensioning mechanism, a standard, a gear housing journalled in said standard, a pair of coaxially aligned shafts extending into opposite sides of said housing, gears secured to said shafts, respectively, in spaced relationship within said housing, a pinion journalled in said housing meshing with said gears, a line spool carried by one of said shafts, brake mechanism carried by the other of said shafts, and means operable selectively to rotate said gear housing in one direction and to retard rotative movement of said housing in the opposite direction.

5. In line-tensioning mechanism, a standard, a gear housing journalled in said standard, a pair of coaxially aligned shafts extending into opposite sides of said housing, gears secured to said shafts, respectively, in spaced relationship within said housing, a pinion journalled in said housing meshing with said gears, a line spool carried by one of said shafts, brake mechanism carried by the other of said shafts, and means operable independent of said brake mechanism, to retard rotation in one direction of said gear housing.

6. In line-tensioning mechanism, a standard, a gear housing journalled in said standard, a pair of coaxially aligned shafts extending into opposite sides of said housing, gears secured to said shafts, respectively, in spaced relationship within said housing, a pinion journalled in said housing meshing with said gears, line spools carried by said shafts, respectively, brake mechanism carried by one of said shafts, and resilient means to rotate said gear housing. i

7. In line-tensioning mechanism, a standard, a gear housing journalled in said standard, a pair of coaxially aligned shafts extending into opposite sides of said housing, gears secured to said shafts, respectively, in spaced relationship within said housing, a pinion journalled in said housing meshing with said gears, aline spool carricd by one of said shafts, brake mechanism carried by the other of said shafts, and resilient means to rotate said gear housing.

8. In line-tensioning mechanism, housing journalled in said standard, a pair of coaxially aligned shafts extending into opposite sides of said housing, gears secured to said shafts, respectively, in spaced relationship within said housing, a pinion journalled in said housing meshing with said gears, a line spool carried by one of said shafts, brake mechanismcarried by the other of said shafts, a spring housing encircling said gear housing, a coil spring within said spring housing having one end connected to said gear housing and the other end connected to said spring housing.

a standard, a gear References Cited in the file of this patent UNITED STATES PATENTS 1,248,186 Smith Nov. 27, 1917

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