US2947516A - Slack puller - Google Patents

Description

R. JACKSON SLACK FULLER Aug. 2, 1960 Filed Oct. 22, 1956 3 Sheets-Sheet 1 INVENTOR. Rom/15y JFICKSON BY 'L 4 W flrraremsvs R. JACKSON Aug. 2, 1960 SLACK FULLER Filed 001;. 22, 1956 2 ;5 a m M d W 5 e 2 m 3 s 3 l IN V EN TOR. Jnc/rso/v gm nnoknsvs 1950 R. JACKSON 2,947,516

' SLACK FULLER Filed Oct. 22, 1956 1 5 Sheets-Sheet 3 INVENTOR. RODNEY JACKSON MQVW SLACK PULLER Rodney Jackson, Seattle, Wash, assignor to Young Iron Works, Seattle, Wash., a corporation of Washington Filed Oct. 22, 1956, Ser. No. 617,548 4 Claims. (Cl, 254-175.7)

This invention relates to improvements in crane loaders and the like, and it has reference more particularly to an apparatus which, in the industry in which it is used, is designated as a slack puller. More specifically defined, the present invention relates to a power driven means arranged in combination with a cable carrying sheave wheel, for example, that of the fair leader block, as mounted at the end of a load lifting crane, for mechanical- 1y drawing out the load lifting cable from the cable winding drum to provide the slack necessary for the attachment of the cable to a load that is to be moved.

For the purpose of better explaining the invention, but not to restrict it to any particular use, it will be here noted that in the present day method of loading heavy logs onto cars or trucks by means of a boom mounted on a base structure which also carries a cable winding drum and its powering means, a cable is extended from the drum outwardly along the boom, over a fairleader sheave wheel at its outer end, and thence to the log or object to be lifted; the cable being equipped at its end with tongs or other suitable means whereby a holding connection with the load may be made. After the connection has been made, the cable is wound in on the drum and the load thereby lifted. Then, by swingingthe boom, the load can be carried to the position of unloading. After the load has been released, it becomes necessary that the cable be pulled out over the fairleader sheave to whatever extent may be required for its attachment to the next object to be handled. Where this pulling out of the cable to provide slack is done manually, the operation is accomplished slowly and with difliculty and in some instances with danger to the workmen.

It is the principal object of this invention to equip the boom of such a load loading apparatus with powered means whereby the load lifting cable can be quickly drawn out from the drum and delivered over the fairleader sheave to the extent desired.

It is also an object of the present invention to provide a powered means that operates in conjunction with the load carrying fairleader sheave, over which the cable operates for a positive pulling of the necessary slack in the cable, and which slack pulling, if so desired, can be done while the boom is being swung from its unloading position back to its loading position.

Yet another object of the invention is to provide a slack pulling means of the above character that is applied to the fairleader sheave block as carried at the outer end of the boom, and which includes a driven friction wheel that is in constant engagement with the cable at the point of its passing over the fairleader sheave, thus to insure instantaneous response.

Further objects of the invention reside in the details of construction of parts embodied in the slack puller mechanism; in their combination, and in their mode of use, as will hereinafter be fully described.

In accomplishing theseand other objects of the invenm P ts tion, I have provided the improved details of construcice tion, the preferred forms of which are illustrated in the accompanying drawings, wherein:

Fig. 1 is a. side View of a typical, present day log loader as equipped with a slack pulling mechanism embodied by the present invention.

Fig. 2 is an enlarged side view of the fair leader block as mounted at the end of the log loading boom; the near side plate of the block being broken away to disclose the sheave wheel driving chain of the slack puller mechanism, and its mounting sprocket wheels.

Fig. 3 is an outer end view of the fairleader blockof the loading boom in which the slack pulling means of the present invention is applied; indicating also the oscillating movement of the block.

Fig. 4 is a vertical section of the fairleader block taken on line 4-4 in Fig. 2.

Fig. 5 is a vertical section taken through the fairleader block on line 55 in Fig. 4.

Fig. 6 is a horizontal section taken on line 66 in Fig. 5.

Fig. 7 is a side view of a loader showing a slack puller as mounted on the boom at a distance from the fairleader.

Fig. 8 is a sectional View through the slack puller mechanism of the device of Fig. 7.

While the present invention is here shown as applied to the boom of a log loader, it is merely to explain the utility of the invention and is not intended to restrict the invention to use with log loaders, or to the specific type of boom or crane employed.

Referring more in detail to the drawings:

In Fig. 1, I have shown a typical log loader to which the present invention is applicable. This loader comprises a mobilized base unit 10 of crawler track type, equipped with turn-table upper structure 11 on which a log loading boom .12 is mounted. As herein shown, the boom 12 is hinged to the turntable structure at its inner end, as at 13, for up and down movement at its outer end; this movement being effected through conventional means, here represented by the cable 14, but not farther described, as it forms no part of the present invention.

At its outer end, the boom 12 is equipped with a fairleader block which is herein designated in its entirety by numeral 15. Mounted within the block 15 on a supporting cross-shaft 16 is a sheave wheel 17 which is herein referred to as the fairleader sheave. It is shown best in Fig. 4, that this sheave wheel 17 is fixed on the shaft 16 by key 18, and that the shaft is revolubly mounted at opposite sides of the sheave in antifriction bearings 19 and 19a that are contained in openings 20 and 20a formed in alignment in the laterally spaced wall plates 21 and 21a which are integral with and constitute a part of the block structure.

At its inner side, the block 15 has a tubular mounting shank 22 rigidly fixed thereto, and rotatably contained in a bearing 23 fixed on the outer end of the boom as seen in Figs. 1 and 2. Thus, the fairleader block has rotatable movement about the axis of the shank so that it will automatically adjust itself to the direction of pull on the log lifting cable as extended therefrom.

The log loading cable used with the present mechanism is designated by numeral 25. It is shown to extend from a cable winding drum 26 mounted on the turntable base structure 11, over a guide sheave 27 on the boom at its elbow bend, thence along the outer end portion of the boom, passing freely through the tubular shank 22 of the fairleader sheave block, over and downwardly from the sheave wheel 17 as noted in Fig. 1. At its end the cable 25is herein shown to be equipped with a pair of log holding tongs 28.

Without use of slack pulling mechanism, it is necessary for workmen to manually pull the cable out from the drum by gripping it adjacent the to'ngs to whatever extent is required for the application of the tongs to an object that is to be lifted. In some instances, this might be a very substantial distance.

I The present slack puller mechanism is mounted in and carried by the fairleader block 15. It comprises the combination of parts that'is best shown in Figs. 2, 4, 5 and 6. It has been shown in Fig. 4, that the sheave wheel mounting shaft 16 is equipped at one end, at the outside of its supporting bearing 19, with a driving spocket wheel 30. It is also shown in Fig. 4, that an electric motor 32 is fixedly mounted in the upper portion of the block 15, extending through openings in the wall plates 21-21a, with its drive shaft 33 parallel to shaft 16. This shaft extends through and is supported from plate 21 by means of a bearing 35 and at its outer end it is equipped with a sprocket wheel 36 in alignment with the sprocket wheel 30.

Mounted between the laterally spaced wall plates 21 and 21a of the sheave block 15 is a small sheave wheel 38.- This is keyed on a transverse supporting shaft 39 which is revolubly carried by bearings 4040' applied to axially aligned openings in two spaced, parallel levers 41 and 41 as has been shown best in Fig 6; the sheave 7 position and as it swings to energize the motor 32 to pay out the cable 25 to provide whatever slack is necessary. By proper manipulation of the boom' while the slack is being paid out, the tongs may be slung to considerable distance, thus saving time and, above all, relieving the workmen of the laborious task of manually pulling the required slack in the cable.

being located between the levers. 'These levers are coextensive and across one end are rigidly joined by a cross-bar 42. At their opposite ends, they are pivotally mounted on a cross-shaft 43 that is fixed in and extends horizontally between the wall plates 2121a.- The sheave 38 bears in rolling contact with and onthe top side of cable 25, above the point where it contacts with the top side of sheave 17, as shown in Fig. 5, and it is yieldingly pressed downwardly thereagainst by a coil spring 45; this spring being loosely applied about a guide pin 46 that projects freely at its lower end through :a hole 47 formed in the cross-bar 42, and at its upper end is adjustably threaded through a block 47 mounted on the wall plate 21a, as shown in Fig. 5. The spring 45, at its upper end, bears against a downwardly facing shoulder 48 on the pin, and the pin is adapted to be longitudinally adjusted in its mounting to vary or change the spring pressure against bar 42.

' It is shown in Fig. 4 that the shaft 39 extends through a vertical slot 50 in the wall plate 21. This provides for a certain freedom of up and down movement of the shaft and sheave 38, and at its outer end theshaft has a small sprocket wheel 51 fixed thereon in alignment with the sprocket wheels and 36 as observed in Fig. 2. A

sprocket chain belt 54 extends about the sprocket wheels 30 and 36 and one run thereof is drawn taut, in driving mesh with the spro'cket wheel 51. The belt arrangement, as seen in Fig. 2, provides that operation of the electric motor 32 drives the spocket wheel 36 in a clockwise direction, and this drives the sprocket wheel 30 in a like direction, and the sprocket 51 in anopposite direction. The ratio of the diameter of sprocket 51 to, diameter of sprocket wheel 30 corresponds to the ratio of the diameter of sheave 38 to sheave 17. Therefore, the sprockets 51 and 30, as driven by the motor 32, will coact to draw out the cable 25 from the drum 26 and feed it. off the sheave 17; this being the slack pulling operation.

It is further to be understood that-under the driving influence of the chainbelt 54, acting through sprocket wheel 51 and its mounting shaft'39, the sheave 38 will be forced down firmly against the cable 25, pressing it into the groove of both sheaves 17 and 38, thus to effect a positive driving grip on the cable to pull it out from the drum 26.

' .It is intended that the motor 32 be controlled by an electrical connection leading therefrom to a source of electric energy carried on the turntable platform.

Assuming that the present slack pulling mechanism is so constructed, the mode of its operation after a log has been lifted and swung by turntable action of the boom to a position of unloading and has been-released by the tongs, it is to swing the boom back toward loading While I have described the device as being operated by an electric motor 32, it is quite apparent that in lieu of this, it would be quite possible and practical to employ an air driven motor, or a hydraulic motor or even a cable driven motor for this purpose. In any instance, it is preferred that the motorbe controlled from the operato'rs position on the turntable structure.

The block 15 may be enclosed by side plates, as indicated at 60 and 61 in Fig. 4, primarily to protect the exposed mechanism shown in Fig. 2. However, the specific design of the block is of no special importance so long as it is not inconsistent with the objects to be attained.

In Figs. 7 and 8, I have illustrated a loader with a slack puller mechanism mounted on the outer end portion of the boom instead of its being contained in the fairleader block. The loader boom, designated in these views by reference numeral 75, carries a fairleader sheave at its outer end over which the loading cable 25 extends.

The slack pulling mechanism is designated in its entirety in Fig. 7 by reference numeral 81 and in Fig. 8, it is shown to comprise an enclosing housing 82 within the base of which a grooved sheave wheel 83 is contained; this sheave being keyed on a transverse axle 84. The loading cable 25 extends through the housing and lies across the top of the sheave 83 and is pressed in the groove thereof by a smaller sheave wheel 86, at one end of a lever arm 87 that, at its other end, is pivoted on a pin 88. Wheel 86 is mounted on the arm 87 by a shaft 89 whereby it is driven as presently explained.

Thesheave wheels 83 and 86 are driven in opposite directions for the outward feeding of the cable 25 between them, by a spro'cket chain belt 90 that operates at one end about a sprocket wheel 91 fixed on the crossaxle 84, and at its other end over a driven wheel 92 on a cross-shaft 93 mounted in the upper end of the housing 82. One run of the sprocket chain belt 90 meshes with a sprocket wheel 94 fixed on the shaft 89. The sprocket wheels 91 and 94 are of the same relative diameters as are the sheave wheels 83 and 86, therefore, the sheaves will rotate at the same lineal speed to cooperate in paying out the cable 25 between them.

Driving friction on the cable 25 is maintained by the feeding wheels 83 and 86 by reason of a coiled spring 95 that is mounted in the housing and bears downwardly against the outer end of lever arm 87.

The shaft 93 is also equipped with a driving sprocket wheel 97 and is driven by a sprocket chain 98 that operates over a sprocket wheel 99 on the drive shaft of an electric motor 100 mounted in the housing 82. v

The mode of operation of this mechanism is substantially the same as that of the device previously described and its objects and results are the same. i

The eflectiveness of the present mechanism is due primarily to the fact that the load supporting sheave 17 is driven and, by reason of its size, afiords' an extended frictional contact surface with the cable. Also, by reason of the fact that the drive wheels 17 and 38 are always in driving contact with the cable, and are pressed tightly against it by the force of spring 45 augmented by the pull of the driving sprocket chain.

While I have shown the present mechanism applied to a boom of angular form, it is to be understood that I do not desire that the invention be confined thereto, since it is applicable to various types of machines with various kinds of booms and be mounted either at the end thereof, as in Fig. 1, or spaced from the end as in Fig. 7.

By driving both the cable engaging sheave wheels, 17 and 38 as seen in Fig. 4, and 83 and 86 as seen in Fig. 8, which wheels are always in constant contact with the cable, an instantaneous response is made possible.

Furthermore, in respect to the showing in Fig. 5, that the load carrying cable is drawn about an extended arcuate portion of the wheel, this also facilitates the quick respouse and eliminates slippage between cable and sheaves.

What I claim as new is:

1. An integral fairleader and slack puller assembly comprising a frame, mounting means fixed to one side of said frame whereby the assembly is adapted to be mounted upon the end of a boom and through which mounting means a cable is adapted to be passed into the assembly, a load sheave rot-atably journalled within said frame and adapted to pass a cable thereover with the cable issuing generally downwardly from the fairleader assembly whereby the cable is wrapped about a substantial portion of the periphery of the load sheave, said load sheave constituting the main load support for the cable, a motor mounted on said frame and having a drive connection with said load sheave for selectively imparting rotary motion thereto, and means mounted within said frame for pressing the cable tightly against said load sheave when said motor is imparting rotary motion to said load sheave so that cable will be payed out from said load sheave, the disposition of the mounting means for the assembly being so related to the load sheave that the cable is Wrapped around at least approximately 45 of the circumference of the load sheave so that wear is minimized on the cable when the same is being payed out from the load sheave.

2. The assembly as defined in claim 1 wherein said frame includes rigidly joined laterally spaced plates, an

axle rotatably mounted by and extending through said plates, said load sheave being fixed on said axle between the plates, a sprocket fixed on one end of said axle, said motor having a shaft extending therefrom, a sprocket fixed on the motor shaft, and a belt operating over the sprockets fixed to the motor shaft and axle and constituting the drive connection between the motor and the load sheave.

3. The assembly as defined in claim 2 wherein said cable pressing means comprises an arm pivotally mounted at one end thereof between said plates, a pressure sheave carried adjacent the opposite end of said arm, and resilient means bearing against the opposite end of the arm to urge said pressure sheave toward said load sheave.

4. The assembly as defined in claim 1 wherein said cable pressing means comprises an arm pivotally mounted at one end thereof between said plates, a pressure sheave carried adjacent the opposite end of said arm, and resilient means bearing against the opposite end of the arm to urge said pressure sheave toward said load sheave.

References Cited in the file of this patent UNITED STATES PATENTS 2,245,434 De Rabot June 10, 1941 2,249,185 Smaltz et al July 15, 1941 2,279,853 White Apr. 14, 1942 2,315,628 Lamond Apr. 6, 1943 2,588,177 Teubner Mar. 4, 1952 2,650,066 Troyer Aug. 25, 1953 2,662,733 Allenbaugh Dec. 15, 1953 FOREIGN PATENTS 1,019,361 France Oct. 29, 1952

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