US2037958A - Excavating shovel - Google Patents

Description

m L T1935, w. BAKER 2 937 9525 3 EXCAVAT INC- SHOVEL Filed March 28, 1934 2 Sheets-Sheet 1 i NVEN TOR.

Patented Apr. 21, 1936 UNETED STATES PATENT OFFICE EXCAVATING SHOVEL Application March 28, 1934, Serial No. 717,778

7 Claims.

This invention relates to power shovels of the type in which thrusting or shifting of the dipper handle is effected by cables actuated and controlled from the main frame.

The general object of the present invention is to simplify and improve the construction and operation of shovels of this character.

A more specific object of the invention is the provision of means whereby the working tension of the hoisting cable is utilized to produce any desired degree of end thrust upon the dipper handle.

Another object of the invention is to provide means for securing the above result in which there are. no sharp bends in the various cables and in which there is ample clearance between the working parts and cables of the device.

Another object of the invention is to provide, in a device of the above character, means for producing end thrust on the dipper handle, and in which the substitution of different sizes of a single member will produce different degrees of end thrust.

Another object of my invention is to provide an improved means of securing control and movement of the dipper stick.

Another object of my invention is to provide means for securing control of the crowding action of a power shovel.

Another object of my invention is to provide means of securing control of the crowding action in which the position and relation of the parts of the control means are not changed or varied with changes in position of the boom.

Another object of my invention is to provide means for relieving the high tensions which might obtain in the dipper shifting cables.

Other and further features and objects of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying drawings and following specifications, wherein is disclosed a single exemplary embodiment of the invention, with the understanding, however, that such changes may be made therein as fall within the scope of the appended claims, without departing from the spirit of the invention.

In the drawings:

Figure 1 is a view in side elevation of the excavating mechanism of a power shovel constructed in accordance with one embodiment of my invention.

Figure 2 is a detail view of the mounting of the dipper handle in the boom and of the thrust producing means as they would appear looking downwardly lengthwise of the handle.

Figure 3 is a diagrammatic or phantom View showing the arrangement of the various cables and other parts of a device constructed according to my invention.

Figure 4 is a view in side elevation of the excavating mechanism of a power shovel constructed in accordance with another embodiment of my invention.

Figure 5 is a partial plan view showing the crowding control mechanism of the power shovel shown in Figure 4, and

Figure 6 is a diagrammatic or phantom View showing the arrangement of the various cables and crowding control mechanism of a device constructed according to the embodiment of my invention illustrated in Figures 4 and 5.

In the drawings the numeral l0 designates the boom, which may be of any suitable construction, and which is pivotally attached for vertical movement to a rotating base II by means of the pivotal connection I2. The base II is adapted for rotational movement by means of structures of usual construction. A hoisting drum I3 and auxiliary or lifting drum M are rotatably mounted upon the base II by suitable brackets I6 and may be driven and braked by the usual prime mover and suitable clutch and brake mechanism known to the art.

The boom is adapted to be raised or lowered to various positions of vertical adjustment by any well known means, such as a cable I! adapted to connect the outer end of the boom with the base II. The boom shown is of the plate girder type so constructed that a dipper handle [9 may slide up and down or shift between the sides 2i and 22 of the boom and may be swung inwardly and outwardly with reference to the base of the machine.

Any suitable means may be employed to permit lengthwise shifting and swinging movements of the dipper handle H. A preferred structure, however, is shown in the drawings, and this structure includes a shipper shaft 23 which extends transversely across the upper face of the boom in at a point substantially mid-way of its length just below and to the rear of the dipper handle (9. The shipper shaft 23 is rotatably mounted on the boom It by means of brackets 24, and a saddle block 26 is loosely mounted on the shipper shaft 23 to permit pivotal movement of the saddle block about the shaft 23. A sheave or roller 2'! is mounted on the shipper shaft 23 and rotates with .it, and the sheave is grooved as indicated at 28 to act as an idler puhey for the cables 3| and 32 which produce endwise shifting movement of the dipper stick Hi. The flat flanges 29 of the sheave 21 serve as a roller for the dipper stick H! to ride upon and the saddle block 26 holds the dipper stick in relatively close sliding engagement with the roller or idler pulley 21. t is apparent that since the saddle block 26 may rotate on the shipper shaft 23 the dipper stick may swing freely in a pendulum-like motion with respect to the boom l0 and base I I except for the control afforded by the hoisting and shifting cable as hereinafter described.

The dipper 36 is of usual construction and is mounted on the lower end of the dipper stick l9 in the usual manner. A padlock pulley 31 is pivotally attached to the upper front edge of the dipper 36 according to the usual construction. The structure so far described is known to the art and is exemplified in Patent #1323323 to Robinson issued December 2, 1919. The structure I am about to describe is believed to be new to the art and is particularly well adapted to secure a powerful thrusting action on the dipper stick and dipper while the dipper is being swung as in digging.

A second cross shaft 4| is rotatably mounted, by means of suitable brackets 42, to the rear of and below the shipper shaft 23 and is also mounted on the upper face of the boom l0. One end of the shaft 4| projects well beyond the side 2| of the boom l0 and a relatively large sheave 43 is mounted on the projecting portion of the shaft. A smaller drum 44 is mounted on the shaft 4| between the brackets 42 and, since the sheave 43 and drum 44 are secured to the shaft 4|, all rotate together.

The hoisting cable 46 passes from the hoisting drum i3, up along one upper edge of the boom l0 (46a), over a pulley 4'! on the outer end of the boom, down to the padlock pulley 3'! (46b) back up to the pulley 48 (46c), and down along the other upper edge of the boom l0 (46d) to the uppermost portion of the sheave 43. The sheave 43 may be termed the drive sheave. The cable 46 wraps several times around the drive sheave 43 and the end of the cable is then fastened to the sheave. The different portions of the hoisting cable 46 have been given the successive numerals 46a, 46b, 46c and 46d, in the order of their description.

The driven drum or thrusting drum 44, as it may be termed, has a sufficient number of turns of cable 3| wrapped about it to give the dipper stick |9 a complete shifting movement from end to end. The cable 3|, termed the thrusting cable, then passes from the drum 44, beneath the roller 21, and up to a suitable fastening means 49 at the upper end of the dipper stick [9. The dipper lifting cable 32 passes from the drum |4, over the roller 2'1, and down to a fastening means 5% at the lower end of the dipper stick.

It is apparent now that rotation of the drum M in a clockwise direction will produce lifting movement of the dipper 36 by longitudinally shifting it in an upward direction and that releasing the drum M will permit the dipper to move downwardly. It is apparent also that a counter clockwise rotation of the hoisting drum l3 will result first in a swinging movement of the dipper as required in digging.

It is apparent also that the end of the hoisting cable 46 which wraps about the drive sheave 43, which may be termed the free end, will impart a turning moment in a clockwise direction to this sheave. This turning moment is conveyed by the shaft 4| to the thrusting drum 44 and the cable 3| imparts the force derived from the turning moment to the upper end of the dipper stick I9 to cause a downwardly acting or downwardly thrusting force on the dipper stick, which, by reason of ratio of the diameters of the drive sheave and thrusting drum, will be greater than the force imparted by the tension in the cable 46. The system, including the drive sheave 43, the shaft 4| and thrusting drum 44, may be termed the differential or differential reduction means. The relative diameter of the drive sheave 43 and thrusting drum 44 may be so chosen as to give almost any desired force to this thrusting action. For instance, the diameter of the drive sheave 43 and thrusting drum 44 may be in the ratio of three to one and the thrusting force applied downwardly on the dipper will be three times the tension in the hoisting cable 45.

Any desired ratio of thrust to hoisting cable tension may thus be secured by substituting various sizes of drive sheaves and thrusting drums, and in this manner the thrust may be varied at will to meet various digging conditions. A hard material, for instance, such as rock or the like might require a ratio of four to one, while a soft material might require only a ratio of two to one.

It is apparent, by an inspection of the drawings, that the hoisting cable 46 passes out to the end of the boom on one side thereof, down to the dipper and back, and down to the drive sheave 43 on the other side of the boom, without interfering with the dipper handle in its shifting and swinging movement, and without interfering with the thrusting cable 3| or the lifting cable 32.

If it is desired to counteract the thrusting effect of the thrust cable 3| set up by the hoist cable 4| it is only necessary to lock or brake the drum M in accordance with the usual practice, and thus cause the lifting cable 32 to carry the thrust set up by the hoisting and thrusting cable.

It is apparent, by inspection of the drawings, that the free end of the hoisting cable has only a relatively limited movement and that the portion of the cable which passes over the pulley 41 and padlock pulley 31 is subjected to the greater movement, which is of course, a very desirable condition, since this condition results in minimum wear of the hoisting cable and minimum friction loss.

In Figures 4, 5 and 6 I have illustrated another embodiment of my invention. This structure employs substantially the same shovel supporting and actuating mechanism shown in Figures 1, 2 and 3, but employs a modified form of mechanism for effecting lengthwise shifting of the dipper stick or dipper handle I 9.

This modified structure may be used to relieve some or all of the tension which might occur in the crowding cable of the device shown in Figures 1, 2 and 3. For instance, if a relatively large drive sheave is used excessively high tension might occur in the crowding cable under adverse digging conditions such as would be encountered in digging in clay or gravel. The device hereinafter described may be utilized by the operator to relieve any excessive tension on the crowding cable.

In this embodiment of the invention a cross shaft 5|, similar to the cross shaft 4|, is employed, and this shaft is rotatably mounted by means of suitable brackets 52 and 52a on the upper face of the boom l0,to the rear of and below the shipper shaft 23. A drive sheave 53 is mounted on a projecting portion. of the shaft 5|, but in the present instance the shaft projects on the opposite face of the boom from its position shown in Figures 1, 2 and 3. In this connection it is to be noted that the arrangement of cables and drive sheaves in the device shown in Figures 1, 2 and 3 may be changed so that the cables pass from the hoisting drum I3 to the dipper and back to the drive sheave in a different order, that is, the drive sheave 43 and differential reduction means may be placed in reversed relation on the boom I without materially changing the structure and operation of the device.

In this embodiment of the invention a double drum 54 may be employed for producing endwise shifting of the dipper stick, and both lifting and crowding of the dipper stick is controlled by the ,dipper control drum 54. It is to be noted that a lifting cable 55 is secured to the lower end of the dipper stick as indicated at 57, passes up along the stick, over the roller 58, and back down the boom to the shifting control drum 54, where it passes several times around the drum and is then secured thereto.

The crowding line BI is secured to the upper end of the dipper stick l9, as indicated at 52, passes along the stick and beneath the roller 58, and back down the boom H] to the underside of the shifting control drum 54. The crowding cable 6| passes several times around the shifting control drum 54 and is secured thereto. It is apparent, from this description, that rotation of the dipper shifting control drum 54, in a clockwise direction will cause crowding of the dipper, while rotation of this drum in the counter clockwise direction will cause lifting of the dipper stick I9.

Rotation of the drum 54 to cause crowding of the dipper is secured in substantially the same manner as before. The hoisting cable 46 passes from the hoisting drum I3 up over the pulley 48, down to the padlock pulley 31, back up to the pulley 41, and down the boom to the crowding drive sheave 53.

Instead of bringing the lifting cable 66 directly up to the roller 58, in this embodiment of the invention, I bring this cable up to the upper side of a lifting sheave 61. This lifting sheave is secured to the shaft between the shifting control sheave 54 and the bracket 52. The lifting cable fifi'passes several times around the sheave 61 and is then secured thereto.

It is apparent that if the lifting cable 66 is wound in by the lifting drum l4, rotation of the drum 61 in a counter clockwise direction is secured, to thus rotate the shifting control drum 54, in the same direction, to lift the dipper. If the lifting cable 66 is locked by means of the braking mechanism of lifting drum M then the biasing action of the hoisting cable 46 is counteracted. If it is desired to produce a modified or decreased crowding action on the dipper stick the brake controlling the lifting drum [4 may be slipped to permit the cable 66 to be paid out slowly.

The lifting sheave and lifting cable 66 may be, in this embodiment of the invention, employed as a control for the crowding action of the hoisting cable. By entirely releasing the brake controlling drum I4 the full crowding action may be secured. By slipping the brake on drum 14 any desired. degree of crowding action may be secured. By looking the brake of the controlling drum [4 the crowding action of the hoisting cable may be entirely counteracted. By rotating the lifting drum l4 the crowding action of the hoisting cable may be counteracted and the dipper stick lifted. It is not necessary to provide means for rotating the drum 14 in the opposite direction. from the lifting direction of rotation since the crowding action of the hoisting cable 46 will produce this rotation of the lifting drum l4.

It is apparent therefore that, with the embodiment of the invention shown in Figures 4 to 6, inclusive, the crowding action of the hoisting cable may be readily controlled and with this embodiment of the invention it is seldom necessary to make'any change in. size of the drive sheave 53. The diameter of the lifting sheave 61 is preferably less than that of the diameter of the drive sheave 53, and greater than the diameter of the shifting control sheave 54 but, of course, any suitable diameter of the lifting sheave 61 may be used.

The control means may be utilized to relieve excessive loads on the crowding cable when necessary, as for instance when a large diameter of drive sheave is being used and the shovel is being used for digging in gravel, clay or the like.

It is apparent that modifications may be made by those skilled in the art and such modifications may be made without departing from the spirit and scope of my invention as set forth in the appended claims.

I claim:

1. In an excavating shovel, a boom, a dipper stick mounted for thrusting and swinging movement with respect to the boom, a hoisting cable for swinging the dipper, an idler on the boom, a cross shaft on the boom, a drive sheave and a thrusting drum on the crossshaft, a hoisting cable trained over the end of the boom down to the dipper and back up over the end of the boom and down to the drive sheave, a thrusting cable trained from the thrusting drum beneath the idler pulley to the upper end of the dipper stick and a lifting cable trained over the idler pulley and down tothe lower end of the dipper stick.

-2. In an excavating shovel, a boom, a dipper stick mounted for endwise shifting and swinging movement with respect to said boom, a hoisting cable for producing swinging movement of the dipper, means for training the free end of the hoisting cable to a drive sheave, a drive sheave and a thrusting drum connected together and mounted for rotation about a single axis on the boom, and a thrusting cable trained from the thrusting drum to the upper end of the dipper stick to produce thrusting movement thereof, and a lifting drum mounted for rotation about the same axis as the drive sheave and thrusting drum and connected thereto and a lifting cable connected to the lifting drum for lifting the dipper stick and holding the same.

3. In an excavating shovel, a base, a boom mounted for vertical pivotal movement on the base, a dipper stick mounted for endwise shifting and for swinging movement with regard to the boom, idler pulleys at the upper end of the boom, a dipper on the end of the dipper stick, a padlock pulley on the dipper, hoisting and lifting drums on the base, a cross shaft rotatably mounted on the upper face of the boom below the junction of the dipper stick and the boom, and having one end thereof projecting beyond the boom on one side at right angles thereto, a drive sheave mounted on the projecting portion of the cross shaft, a thrusting drum mounted on the cross shaft within the planes defined by the sides of the boom, a shipper shaft and roller mounted between the cross shaft and the dipper stick, a hoisting cable trained from the hoisting drum over one of the pulleys on the upper end of the boom, down to the padlock sheave, up over the other of the pulleys on the end of the boom, and down to the drive sheave, a thrust cable trained from the thrusting drum beneath the roller and to the upper end of the lifting stick, and a lifting cable trained from the lifting drum over the roller and down to the lower end of the dipper stick.

4. In an excavating shovel, a boom, a dipper stick mounted for swinging and shifting movement in relation to the boom, a hoisting cable for swinging the dipper, means for imparting thrusting force to the dipper comprising a differential reduction means adapted to be actuated by the free end of the hoisting cable, a cable passing from the differential reduction means to the upper end of the dipper stick, another cable passing from the differential reduction means to the lower end of the dipper stick, and means for controlling the thrusting action of the differential reduction means and for lifting the dipper stick comprising a control sheave associated with the differential reduction means and actuated through the lifting and hoisting cable by the lifting and hoisting drum.

5. In an excavating shovel, a boom, a dipper stick mounted for endwise shifting and for swinging movement with respect to said boom, a hoisting drum and hoisting cable for swinging the said dipper, a differential reduction device mounted on the boom and having the free end of the hoisting cable attached thereto to produce rotation thereof, a thrusting cable adapted to be pulled by the reduction means through the agency of the hoisting cable, a lifting cable secured to the dipper stick and to the reduction means at the other end thereof, a lifting and holding drum, a lifting and holding cable from the lifting and holding drum to the differential reduction device, and means associated with the differential reduction device adapted to be actuated by the lifting and holding cable to control the thrusting action in the thrusting cable, and to rotate the reduction device in'the opposite direction.

6. In an excavating shovel, a base, a boom connected for vertical pivotal movement on the base, a. dipper stick mounted for endwise shifting and for swinging movement with regard to the boom, a roller pulley mounted upon the boom and below the dipper stick and having rolling engagement therewith, a cross shaft mounted upon the boom below the roller pulley and having one end thereof projecting beyond the face of the boom, a drive sheave mounted upon the projecting end of the cross shaft, a thrusting drum mounted upon the cross shaft within the planes defined by the vertical faces of the boom, a pair of idler pulleys on the ends of the boom and a hoisting cable trained over one of the pulleys on the end of the boom, down to the dipper stick, back up over the other of the idler pulleys and down along the side of the boom to the drive sheave, a thrusting cable secured to and wrapped about the thrusting drum and passing beneath the roller pulley and up to the upper end of the dipper stick, and a lifting cable passing over the upper side of the roller pulley and down to the lower end of the dipper stick.

'1. In an excavating shovel, a boom, a dipper stick mounted for endwise shifting and for swinging movement with respect to said boom, a hoisting drum and hoisting cable for swinging the dipper, a differential reduction device mounted on the boom and having the free end of the hoisting cable attached thereto to produce rotation thereof, a thrusting cable adapted to be pulled by the reduction means through the agency of the hoisting cable, a lifting cable secured to the dipper stick and to the reduction means at the other end thereof, a lifting and holding drum, a lifting and holding cable from the lifting and holding drum to the differential reduction device, a central sheave associated with the differential reduction device adapted to be actuated by the lifting and holding cable to control the thrusting action in the thrusting cable and to rotate the reduction device in the opposite direction.

WALTER BAKER.

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