US1436725A - Cable guard for tackle blocks - Google Patents

Description

W. J. ROBERTSON AND H. E. BECKER. CABLE GUARD FOR TACKLE BLOCK-S. APPLICATION FILED JAN. 23. 1922. 1 ,4361425. Patented NOV. 28, 1922.,

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CABLE GUARD FOR TACKLE BLOCKS.

Application filed January 23, 1922. Serial No. 531,134.

To all whom it may concern: 7

Be it known that we, WILLIAM J. ROBERT- SON and I'IARRI E.'BncKnR,' citizens of the United States, residing at Fullerton, in the county of Orange and State of California,

have invented a new and useful Cable Guard for Tackle Blocks, of which the following is a specification.

This invention relates to cable guards for tackle-blocks'and has for an object to provide a guard which offers a maximum amount of protection preventing the limbs or clothing of the user or others, or any other object, becomingcaught in the sheaves. A further object Is to provide a device which will always maintain the cable in the cable grooves of the sheaves so that upon a spreading apart of the cable any tendency of the cables to climb out of sald grooves will 'be eliminated.

Another object is to provide a guard so formed as to deflect the block, away from any object with which it contacts and to prevent the block becoming caught on the upper structureof an oil well derrick, when used in connection with oil well apparatus,

or upon the upper structure of such other apparatus with which it may be utilized.

A further object is to provide a guard formed to constitute a skid or shoe upon which the block may rest when not m use and upon which the block may he slid without injury to the sheaves.

Various other objects and advantages will be more fully apparent from the following description of the accompanying drawings, which form a part of this disclosure, and which illustrate a preferred form of embodiment of the invention.

0f the drawings:

Fig. 1 is a side elevation, partly in section, showing the guard of the present invention applied to a standard type of four sheave tackle-block.

Fig. 2 is an elevation viewed from the right side of Fig. 1. 1

Fig. 3 is a detail plan section on line 3-3. of Fig. 1.

In the drawings. the cable guard. of the present invention is shown as applied to a tackle block such as is generally utilized as a part of the ordinary well drilling and operating equipment, and in suchuse it is the ordinary practice to reeve the cable oyer the crown pulleys at the top of the derrick and around the sheaves of the block. Blocks of this character are of relatively large size and in their use many serious accidents have been occasioned by workmen falling from the derrick onto the block and being dragged into the sheaves, also .it is not unusual thatsthe limbs 01' clothing of workmen handling such block become caught in the sheaves where the block is without some form of protective device. Further, tools or other articles dropped from the derrick onto such blocks often become caught and dragged into the sheaves, causing the sheaves to jam and the entire block to be lashed or jerked around in a dangerous manner before the power can be thrown off.

The device of the present invention functions as a protection against such abnormal or detrimental occurrences,.and while we have illustrated our invention as applied to a four-sheave block of a standard design it is to be understood that it may be also applied to other types of tackle-blocks with equal results. y

The block, as shown in the drawings, comprises two op osed side plates 1, and a plurality of partltion plates 2, secured together at their opposite ends bytransverse pivot bolts 3 and 4, .the plates being maintained in spaced relation by the hub portions 5, 6, of the upper and lower. bails 7 8, respectively, "and by spacing elements 9 as shown in Fig. 2, this being the eneral frame structure of standard tacklelocks. The cable sheaves 10 are positioned between ..the partition plates and are journaled on a shaft 11 extending through the several partition plates and the opposed side plates.

The protective means consists of two guard elements 12 each detachably connected to the opposite side plates 1 and extending across and adjacent the faces of the cable sheaves, and as the two guard elements are of duplicate construction, a detailed descriptionof only one thereof will herein be given.

The guard element 12 comprisesa shield having a solid wall 13 angled downwardly and inwardly from a rounded apex portion 14 approximately opposite the axis of the sheaves, and a wall 15 angled upwardly and inwardly from said apex portion 14, the

edges of the walls 13 and 15 being 'oined by side walls 16 and forming an enc osing housing for the several cable sheaves. Each side wall 16 at its upper and lower ends abuts against the vertical edge of the respective side plate 1 of the block as at 17 and are provided with ears 18 which overlap the sides of said plates to which they are attached by bolts 19.

The upper edge of the wall 15 is provided with notches 20 each engaging over the edge of one of the partition plates 2 and said wall is provided with vertically disposed slots 21 to accommodate the upwardly extending tangential cable runs 30, each slot being in alignment with one of the cable sheaves and extending from the upper edge of said wall downwardly to a point just above .the rounded apex portion 14. The lower edgeof the wall 13 is rounded inwardly so that said wall may function as askid or shoe permitting the block. to be dragged thereon when not in use, and without injury to the sheaves.

In forming the walls of the guard elements in the angular disposition shown, we have provided a means by which the block will be deflected away from any object it may contact during its travel instead of becoming caught upon such object. This is of particular importance, especially in the use of the block with oil wellequipment asin such heavy duty use a block becoming caught upon the derrick structure would Wreck the derrick before the power could be thrown off.

This guard structure provides a strong and cheap protective device having no movable parts to become disarranged or broken, and effectively prevents the limbs, bodies or clothing of workmen becoming caught in the cable sheaves.

Having described our invention, we

claim:

1. A cable guard for a tackle-block, comprising a caslng having an open side and a wall extending upwardly and outwardly to its medial portion and then upwardly and inwardly to its top edge with the up er portion of the wall slotted downwar ly from said top edge to provide a cable way, the casing having means adapting it for at 'tachment to the frame of a tackle-block with the wall extending across theface of the sheave thereof.

2. A cable guard for a tackle block, comprising a casing having an open side and a wall having a lower portion angled up-' wardly and outwardly to a medial apex portion and an upper portion angled upwardly and inwardly from said apex portion to the upper edge with said upper portion slotted downwardly from its u per edge to provide a cable way, the casing av-- ing abutment surfaces to engage the frame of a tackle block and apertured ears adapting it for attachment to the frame of the tackle block.

3. A cable guard for a tackle-block, comprising a casing having an open side and a wall having a lower portion angled upwardly and outwardly to an apex portion and an upper portion angled upwardly and inwardly from said apex portion to the upper edge with said upper portion slotted downwardly from its upper edgeto provide a cable way, the opposite corner portions of the casing being provided with means adapting it for attachment to the frame of a tackle-block with the wall extending across the face of the sheave thereof.

4. A cable guard combining a tackleblock having opposed side plates and a rotary cable sheave between the plates, a cable rove around the sheave and having an upwardly extending tangential run, a guard member fixed to the plates and extending across and around the faceof the sheave with its u per portion extending inwardly and beyond the cable run, said member having an open slot extending downwardly from its top edge to form a cable way.

5. A cable guard combining a tackleblock having opposedside plates and an intermediate partition plate, cable sheaves on opposite sides of said partition 'plate, a

guard member carried by the side platesan'd extending across and around the faces of the sheaves with its top edgenotched for intermeshing engagement with the partition plate and with its u per portion provided" with slots extending. downwardly from said top edge to provide cable w Signed at Los Angeles, 17th day of January, 1922.

WILLIAM J. ROBERTSON. HARRY E. BECKER.

Witnesses:

CLARENCE B. Fos'rER, L. BELLE WEAVER.

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