US2182292A - Automatic cathead - Google Patents

Description

es. s, 1939. w GUER 2,182,292

AUTQMATIC CATHEAD Filed Oct. 22, 1957 Z/Ziiam 611m INVEN 30 ATTORNEY Patented Dec. 5, 1939 UNITED STATES PATENT OFFICE AUTOMATIC CATHEAD partnership Application October 22, 1937, Serial No. 170,468

4 Claims.

This invention relates to a cathead structure and particularly to an improved and simplified form having automatic means for winding a line thereon and then releasing the line. Catheads are commonly used in oil well drilling rigs and one common use is to operate a line or cable attached to pipe tongs for loosening joints of pipe or couplings. In operating pipe tongs for this purpose, it is desirable to produce an oscillating movement of the tongs and catheads which provide automatic means for alternately winding and then releasing the line are especially desirable for this purpose.

A principal object of the improved structure of this invention is to provide a simplified form of cathead structure which is positive in operation and has relatively few moving parts, which are easily accessible for repairs or replacements.

Other objects and advantages of the improved structure of this invention will be readily understood from the following detailed description taken in conjunction with the accompanying drawing which illustrates a preferred embodiment of my invention.

In the drawing:

Fig. 1 is a plan view of a portion of the draw works mechanism of a conventional drilling rig showing the general arrangement of the cathead shaft, cathead and tong operating mechanism.

Fig. 2 is a side elevation of the cathead structure proper.

Fig. 3 is an end elevation of the cathead structure with part of the housing broken away for illustrative purposes.

Figs. 4 and 5 are fragmentary views of Fig. 3 illustrating two additional positions of the cathead mechanism.

Fig. 6 is a detail of the coupling members of the structure.

Referring to the drawing and to Figs. 1 and 2 in particular, a portion of a conventional draw works frame IE3 is shown having a cathead shaft extending therethrough and suitably journalled in opposite sides of the frame. On one end of shaft H which extends beyond one side of frame I9, is mounted the usual cathead spool |2. Mounted on shaft intermediate spool l2 and frame I is the cathead structure embodying my invention and denoted generally by l3. A drive sprocket i4 is mounted on shaft H and a chain l operatively engages sprocket l4 and is connectedto a suitable power supply source, not shown, since these connections for driving a cathead shaft are conventional and well understood by those familiar with drilling rigs. A control handle it is suitably mountedon frame It and 7 is operatively connected by means of a control member I! to a control lever it (Fig. 3) which operates the cathead mechanism in a manner to be more fully described hereinafter. 19 are shown in operating position on a section of pipe 20 and a tong line 2|, which is preferably a conventional wire cable, is connected to the free end of tongs I9 and leads into the cathead mechanism.

The cathead mechanism proper comprises a circular housing 22 having spaced parallel sides 22a and 22b and having an opening in its lower side for admission of tong line 2|. Within housing 22 and fixedly mounted on shaft I! is a winding drum 23 having a central groove 24 for reception of tong line 2|. A portion of the peripheral surface of drum 23 is cut away to form notch 25 (Figs. 3 to 6 inclusive) having one relatively long face 26 sloping inwardly from the peripheral surface of the drum, the other face 21 forming an acute angle with the periphery of the drum. A coupling member 28 is rigidly mounted in notch 25 against face 2'! and has a curved portion spaced from face 26 and facing outwardly toward the periphery of drum 23 and in the direction of rotation of drum 23 as indicated by the arrow in Fig. 3. Coupling member 28 is preferably removably insertable in notch 25 and after insertion, may be fixed against dislodgment by welding or by means of set screws or other suitable fastening devices. Also member 28 is so positioned in notch 25 that it is substantially entirely within the periphery of drum 23.

The end of the tong line 2| which enters the opening in the lower portion of housing 22 has fixedly attached thereto a hook 29 adapted to operatively engage coupling member 28. The butt end of hook 29 is squared to provide shoulders 36 extending on opposite sides of line 2|. At an intermediate point on the upper surface of hook 29, a bill curves upwardly from the body of the hook and rearwardly toward the butt of the hook,- the curvature of bill 35 being complementary to that of coupling member 28. From the point of bill 35, the upper surface of the hook tapers downwardly toward the lower surface of the hook forming a tapered tip 34.

The end of tong line 2| bearing hook 29 is supported within the opening in the housing 22 on the upper surface of a thrust finger 30, which is provided at one end with opposite laterally extending trunnions 3|, which are journalled in sides 22a and 22b of the housing. Control lever Pipe tongs 4-8 is rigidlyconnected to one of the trunnions k6 3| and operation of lever l8 by means of control member H from handle l6 actuates finger 30 to raise line 2| and hook 29 into engagement with coupling member 28. A pair of release plates 32 are mounted opposite each other on opposite sides 22a and 221) within the opening in housing 22. Release plates 32 enclose finger 3|) and line 2| between them, acting as guides for these members. The forward edges of release plates 32 provide abutments which act as supporting guides and stops for shoulders 36 of hook 29 and prevent dislodgment of the end of tong line 2| and hook 29 from the housing 22 when the structure is assembled. The upper edges of release plates 32 are provided with trip lugs 33 which extend toward each other and form a bridge above line 2| to act as a guide therefor and to prevent fouling of the line. Lugs 33 are positioned outside the periphery of drum 23 but in the path of movement of tip 34 when the hook is engaged with coupling member 28. Tip 34 is adapted to engage lugs 33 at a suitable point in the path of rotation of hook 29 whereby lugs 33 will force the hook out of engagement with coupling member 28 and release line 2|, as will be described in greater detail hereinafter.

The apparatus'above described is operatedin the following manner:

Shaft II and winding drum 23 will be rotating continuously in counter-clockwise direction and the cathead mechanism will normally be in the position shown in Fig. 3, wherein hook 29'and line 2| rest upon the upper surface of finger 30. When it is desired to operate line 2| to pull tongs l9, handle IE will be moved and the movement transmitted through control member ll to control lever l8, which will be moved downwardly forcing thrust finger 30 upwardly, thereby moving bill 35 of the hook into the path of rotation of drum 23 and into engagement with coupling member 28, as illustrated particularly in Fig. 4. Due to the shape of notch 25 and the form of hook 29, bill 35 will enter notch 23 and be guided by face 26 into engagement with the curved portion of coupling member 28. At the same time, due to the taper of tip 34, the tip will extend outwardly beyond the periphery of winding drum 23. Upon engagement of the hook and coupling member, line 2: will be wound upon drum 23 within groove 24, thereby applying tension to line 2| sufiicient to operate tongs l9. When drum 23 has turned through an almost complete revolution, tip 34, since it extends beyond the periphery'of drum 23, will come in contact with lugs 33, as illustrated in Fig. 5, which will act to eject hook 29 out of engagement with coupling member 28, releasing the hook and line 2|.and allowing them to be drawn back to their initial position .where the hook is in position to be re-engaged with member 28 to apply another pull to tongs I9, which, in the interim, will have been returned to its initial position for eife'cting a further turn of pipe 2|). This operation will be repeated until pipe tongs l9 have completed the required work.

As described above, the operation of the cathead structure of this invention automatically effects snubbing of the-tong line through approximately a complete revolution of the winding drum and release of the line at the end of the revolution. However, if snubbing and release at more frequent intervals is desired, additional notches 25 and coupling members 28 may be pro,- vided in the periphery of the drum at points spaced in accordance with the desired interval of release.

In the form of structure described, release plates 32 are preferably detachably connected to sides 22a and 2217 as it is found in practice that the lugs 33 and the upper edges of plates 32 will wear more rapidly than other parts of the apparatus and by making plates 32 detachable, replacements may be made quickly and easily. Similarly with regard to coupling member 28, by making it readily removable from the structure, replacement of this part is facilitated.

The complementary curved locking faces of coupling member 28 and bill 35 of hook 29 assure positive locking connection of these parts when engaged with each other, while at the same time, the curved surfaces make for easy separation when tip 34 is brought into releasing contact with lugs 33, for bill 35 will rotate on the curved surface of member 28 and cause tip 34 to turn farther away from the periphery of drum 23 and thus assure the entry of lugs 33 in the gap formed betweentip 34 and face 26 of notch 25. Also by positioning member 28 substantially entirely within the periphery of drum 23, engagement with hook 29 cannot be effected without positive actuation of finger 30, thus adding to the safety features of the device.

It will be evident, therefore, that the cathead structure of this invention provides an automatic means for snubbing and releasing a line, and consists of only a very few moving parts all of which may be made of relatively rugged construction and relatively easily accessible for repair or replacement.

Various modifications and alterations may be made in the size, form and'details of the cathead structure of this invention without departing from the scope of the appended claims.

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

1. A cathead structure comprising a winding member having a winding surface for a line, a recess extending inwardly from the periphery of said winding member, a coupler member mounted in said recess, a line to be wound on said winding member and having a hook member for engagement with said coupler member for anchoring said line to said winding member, said hook member having a bill adapted to enter said recess and engage said coupler member and a tip extending beyond the periphery of said winding member when said bill is engaged with said coupler member, a release member in the path of said tip to disengage the hook member from the coupler member and means to initially place said hook member in engagement with said coupler member.

2. A cathead structure comprising a housing having spaced parallel side members one of which has an aperture therein, a winding member having a winding surface for a line extending through said aperture into said housing and rotatable mounted therein, arecess extending inwardly from the periphery of said winding memher, a coupler member mounted in said recess, an opening in the lower portion of said housing below said winding member, a line to be wound on said winding member extending into said opening and having a hook member adapted to engage said coupler member whereby said line may be anchored to said winding member, a pair of release members mounted on said side members on opposite sides of said opening in the path of said hook member to disengage said hook member 7 from said coupler member and a thrust member pivotally mounted in said opening and adapted to urge said hook member into engagement with said coupler member. a

3. A cathead structure comprising, a housing having spaced parallel side members one of which has an aperture therein, a winding member having a winding surface for a line extending through said aperture into said housing and rotatable mounted therein, a recess extending inwardly from the periphery of said winding member, a coupler member mounted in said recess, an opening in the lower portion of said housing below said winding member, a line to be wound on said winding member extending into said opening and having a hook member adapted to engage said coupler member whereby said line may be anchored to said winding member, a pair of release members mounted on said side members on opposite sides of said opening, said release members comprising plate members having forward edges which coact to retain said hook member within said housing and upper edges extending into the path of said hook member and adapted to disengage said hook member from said coupler member, and a thrust member pivotally mounted in said opening and adapted to urge said hook member into engagement with said coupler member.

4. A cathead structure comprising, a housing having spaced parallel side members one of which has an aperture therein, a winding member having a winding surface for a line extending through said aperture into said housing and rotatable mounted therein, a recess extending inwardly from the periphery of said winding member, a coupler member mounted in said recess, an.

opening in the lower portion of said housing below said winding member, a line to be wound on posite sides of said opening, said release members comprising plate members having forward edges which coact to retain said hook member within said housing and upper edges extending into the path of said hook member and adapted to disengage said hook member from said coupler 0..

member, and a thrust member pivotally mounted in said opening and adapted to urge said hook member into engagement with said coupler member.

WILLIAM GUIER.

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