US1808770A - Safety cathead - Google Patents

Description

June 9, 1931. c. R. EDWARDS 1,808,770

I SAFETY CATHEAD I 'Filed Aug. 21, 1925 v 2 Sheets-Sheet l I, I I l gwl or fl zwmz 7 June 9, 1931. c. R. EDWARDS 1,308,770

SAFETY CATHEAD Filed Aug. 21, 1925 2 sheets-sheet 2 v Patented June '9, 1931 forms a part of, the conventional draw works UNITED STATES PATENT OFFICE CHARLES R. EDWARDSOF HDUST ON, TEXAS SAFETY GATHEAD Application med August 21, 1925. Serial No. 51,693;

One object of the. invention is to provide a cathead designed to be used with, and which used in well drilling operations, and the invention embodies novel means for operatively connecting the cathead with and disengaging it from the counter shaft of the draw works.-

Another object of the invention is to produce a device of the character described which also embodies a one way brake designed to automatically operate to hold the cathead against backward rotation while sustainin a load and when disengaged from said sha whereon it is mounted.

A further feature of the invention resides in the provision of a device of the character described embodying a novel type of clutch for clutching the cathead with its shaft for rotation with said shaft, when the shaft is rotated in one direction, said clutch permitting the shaftto turn, idly, in the other direction.

With the-above and other objects in view this invention has particular relation to certain novel features of construction, operation and arrangement of parts, an example of which is given in this specification and illustrated in the accompanying drawings, wherein j Figure 1 shows a side elevation of the complete device partly in section.

Figure 2 shows a crosssectional view taken on the line 2-2 of Figure 1,

Figure 3 shows a fragmentary side view of the brake employed, and- Figure 4.- shows a fragmentary sectional view. taken on the line 4-4-of Figure 1.

Referring now more particularly to the drawings, wherein like numerals of reference designate similar parts in each of the figures, the numeral 1 designates the supporting framework of the conventional draw works. The numeral 2 designates the driving counter shaft thereof. Keyed on this shaft there is a sleeve 3, and loosely mounted on this sleeve there is the drum like cathead 4, having at its end, adjacentsaid framework, an enlarged annular friction surface 5.

The cathead is retained on the sleeve 3, by means of an internal nut or plug 6 which is threaded into the outer end of said'sleeve and whose outer end has an annular, outwardly extendin flange 7 which engages against the outsi e of the annular inwardly extending flange 8 carried by the cathead 4.

There is a long, substantially semi-cylindrical key 9 which is adapted to lie in a correspondingly shaped keyway 10, in the inner surface of the cathead 4 and with its flat face substantially flush with the inner surface of the cathead when completely seated in its keyway. The inner end of this key has a right angular arm 11, preferably integral therewith, and with its free end 12 inwardl turned and normally held against the sha 2 b means of the pressure spring 13. 1

his spring iscoiled around the set bolt 14, which is anchored to the adjacent end of the cathead, and it has one end anchored to the cathead, with its other end pressing inwardly against the arm 11. The shaft 2 and sleeve 3 normally turn in the direction indicated by the arrow in Figure 2, and with the arm 11 lying'against the shaft 2 the key 9 will be partly unseated from its seat 10, and turned into the opposing semicylindrical keyway 15 in the outer surface of the sleeve 3, thus forming a clutch and locking the sleeve 3, in driving relation with the cathead 4. Should the shaft 2 be reversed the sleeve 3 will run idly with relation to the cathead, on the pl nciple similar to that of the conventional er clutch. I

There is a clutch releasing'mechanism embodying a loosely mounted collar 16, slidable on the shaft 2 and having the tapering faces,

as 17. This collar. is operatively connected with a yoke 18 which is pivoted to the framework and extended, forming the lever 19.

17 will engage under the outturned end 12 of the arm 11 and hold the same away from the shaft 2 and thus fully seat the key 9 in its seat 10 and permit the sleeve 3 to turn idly in the cathead. By depressing the outer end of the pedal 20, the collar 16 may he released from the arm 11 and the pressure of the spring 13 will cause the key 9 to rise from its seat into interlocking position with the sleeve 3. I

Various kinds of work is done with the cathead in drilling operations. In carrying I out this work a cable. is wound around the cathead and one end attached to a load to be lifted, or other-work to be performed. The outer end of the cable is held, and manipulated, by a workman in the usual way. It sometimes happens that the cathead is released from its shaft while sustaining a load. In order to hold it, to prevent dropping of the load, there'is provided a friction brake.

embodying a band -23 which surrounds the friction surface 5, and also including a lever 2d, ivotd to the bracket 25, which is attached to t e frame 1. The respective ends of the band 23 are attached, one to the free end of the lever 24 and the other at an intermediate 1 end thereof, and a fiat, pressure sprin 26 is 2 load sustained by arranged to press against said lever an tends to tighten the band 23 around the friction surface 5 so as to hold the band in readiness to be frictionally engaged and gripped by the friction surface 5, of the cathead, in casethe cathead isdeclutched from the shaft 2- and starts to turn, under the influence of the it. The cathead will thus be held against reverse rotation.

7 There are obviousl man mechanical variations which may e ma e in the construction of the device and other combina tions in which it may be used, besides its use in connection with draw works.

What I claim'isz- V 1. In a safety device, a cathead, means adapted to support and to drive said cathead,

said cathead being adapted to receive and drive a line by friction while said line is nsoawo ating line and normally revolvable inone direction only, a driving member to rotate the cathead, engaging means for driving said cathead, through said driving member, means through which an operator may hold said engaglng means engaged while said cathead is being revolved and while said line is being operated on said cathead.

4. In a safety device, a cathead to receive- CHARLES 1t EDWARDS.

' manually held in contact with said cathead,

. engaging means whereby said catheadma V be driven in only one direction, means throng which said engaging means maybe held in engaging position by the operator while me nipulating the line, and means preventing -a reverse rotation of said cathead,

2. In a safety device, a support, a cathead adapted to operate or hold a line as said line is manipulated into only a frictional contact therewith, a driving member, operative en gaging means whereby said. cathead ma driven In only one direction by said riv ingnmember only when-said means is held by a e manipulator and means gpreventing a reverse rotation of said catheao.

3. In a safety device, a support, a cathead on the snpport and adapted to receive anciper' j

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