US3884519A

US3884519A - Safety latch for well pipe elevators

Info

Publication number: US3884519A
Application number: US393085A
Authority: US
Inventors: Edward Joseph Mcfadden
Original assignee: Byron Jackson Inc
Current assignee: Varco International Inc; Byron Jackson Inc
Priority date: 1973-08-30
Filing date: 1973-08-30
Publication date: 1975-05-20
Anticipated expiration: 1992-05-20
Also published as: CA1010441A

Abstract

A well pipe elevator has hinged body parts allowing the elevator to be opened and closed, one of the body parts having a pivoted latch engageable with latch lugs on the other body part, the latch being spring loaded to a latching position, and said other of the body parts having an operating handle provided with a safety lock for holding the latch in a latching position. The operating handle is spring loaded to a latch locking position and is manually shiftable to release the lock and to cam the latch open.

Description

United States Patent [191 McFadden I May 20, 1975 SAFETY LATCH FOR WELL PIPE ELEVATORS Edward Joseph McFadden, Houston, Tex.

[75] Inventor:

[73] Byron Jackson lnc., Long Beach,

Calif. v Filed: Aug. 30. 1973 Appl. No.: 393,085

Assignee:

US. Cl. 294/90; 24/249 DP; 24/263 D; 294/102 A Int. Cl E21b 19/06; B66c l/iO Field of Search 294/90, 102 A; 24/249 DP, 24/263 D, 263 DL References Cited UNITED STATES PATENTS 2,067,663 Grau 24/249 DP Smith 294/90 X 9/ l 941 Lundeen 24/263 .DL

2,257,120 2,567,044 9/1951 Wilson 294/90 2,957,724 10/1960 Bujold 294/102 A Primary Examiner--James B. Marbert Assistant ExaminerJames L. Rowland Attorney, Agent, or Firm-John 0. Evans, Jr.

[5 7 ABSTRACT A well pipe elevator has hinged body parts allowing the elevator to be opened and closed, one of the body parts having a pivoted latch engageable with latch lugs on the other body part, the latch being spring loaded to a latching position, and said other of the body parts having an operating handle provided with a safety lock for holding the latch in a latching position. The operating handle is spring loaded to a latch locking position and is manually shiftable to release the lock and to cam the latch open.

8 Claims, 7 Drawing Figures T e21 ll I l PATENTED HAY 2 0 i975 SHEET 3 BF 3 1 SAFETY LATCH FOR WELL PIPE ELEVATORS BACKGROUND OF THE INVENTION Well pipe elevators of the type here involved generally comprise a pair of hingedly interconnected body parts which cooperateto form a circular structure adapted to be applied to and removed from a well pipe, such as a well drilling pipe, to support the well pipe by the hoist equipment in the derrick. The elevator is opened and closed by workmen on the platform and on a monkey board in the derrick. When the elevator is closed about the pipe it must be securely latched closed, so that vibration or transient forces cannot cause the elevator to be inadvertently opened, since such opening of the elevator may result in severe damage to the equipment and to personnel on the derrick floor, and may cause substantial delay in the progress of the well drilling or other operations.

Accordingly, various latching and latch locking mechanisms have heretofore been provided, whereby, when the elevator body parts are closed and latched, a latch lock must be released before the latch can be opened. In most instances, the latch and latch lock mechanisms have been incorporated in the structures requiring that the workmen utilize both hands in opening the elevator, but in some instances the elevator may be opened by one hand, the other hand in some instances being needed only to stabilize the elevator. Such latch and latch locking arrangements have heretofore been either complicated in construction, uncertain in use or difficult to manipulate.

In addition, it may occur that the latch operating mechanism is accidentally operated upon contact with some structure. or equipment in the derrick, since the latch operating mechanisms are generally exposed.

SUMMARY OF THE INVENTION The present invention provides a simple well pipe elevator with a latch and latch locking mechanism combined with a latch operating mechanism, whereby the latch is positively held in a latched condition when the latch is closed, but the latch is opened easily by the operating member following release of the latch lock which is incorporated as a part of the operating member.

More particularly, the invention provides an elevator with a latch arm pivotally carried by one body part and adapted to latch with lugs formed on the companion body part, automatically upon closure of the elevator. The latch is opened by an operating member pivotally carried by the second mentioned body part, by a camming action which reduces the manual force required to overcome the latch closing spring. The latch operating member has integral therewith a latch lock which is automatically positioned relative to the latch to prevent the latch from opening, until such time as the operating member is purposely manipulated to open the latch. The latch and latch lockin'g arrangement is such that any tendency of the latch to open, which may be caused by vibrationor transient forces during use, causes the operating member to be held more forcefully in its latch locking position. I

In addition, the elevator and. the latch operating means are constructed and arranged so that the operating means is disposed close to the elevator body in a location protected against accidental contact with struc-' ture or equipment in the derrick.

This invention possesses many other advantages, and has other purposes which may be made more clearly apparent from a consideration of the form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS- FIG. 1 is a top plan of a well pipe elevator shown in a closed condition and made in accordance with the invention;

FIG. 2 is a side elevation of the elevator of FIG. 1;

FIG. 3 is a fragmentary top plan showing the latch released and the elevator partially opened;

FIG. 4 is an enlarged fragmentary side elevation of the safety latch mechanism as seen in FIG. 2;

FIG. 5 is an enlarged fragmentary top plan showing the safety latch mechanism in a latched and locking condition;

FIG. 6 is a view corresponding to FIG. 5, but showing the safety latch mechanism in a latched but unlocked condition; and

FIG. 7 is a view corresponding to FIGS. 5 and 6 but showing the latch released, just prior to opening of the elevator.

DESCRIPTION OF THE PREFERRED EMBODIMENT As seen in the drawings, the invention is incorporated in a well pipe elevator of the so-called side door type, wherein the elevator has a major body part 1 and a minor companion body part or door 2, hingedly interconnected together. The body part 1 has vertically spaced ears 3 between which a hinge portion 4 on the door 2 is disposed and pivotally or hingedly mounted on a pin 5. A grease fitting 6 is preferably provided to enable lubrication of the hinge connection.

When the elevator is closed, the body parts 1 and 2 cooperate to form a circular pipe opening 7 circumscribed by a shoulder 8 adapted to support a well pipe by engagement beneath a tool joint shoulder or upset on the pipe, as is well known.

At its opposite sides, the body 1 has

outstanding arms

9 and 10 spaced vertically to form openings 1 1 adapted to receive a pair of elevator links, which, as is also well known, are adapted to suspend the elevator from the usual hook, whereby the usual hoist mechanism raises and lowers the elevator in the derrick. Link blocks 12 are pivotally connected at 13 and bolted at 14 to the

link arms

9 and 10 to removably retain the links in the openings 11.

The elevator structure as thus far described is conventional and need not be further described in detail.

In accordance with the present invention, latch means L and latch operating and locking means 0 are provided for releasably latching and locking the door 7 2 in the closed position, as seen in FIGS. 1, 2, 4 and 5, the operating means 0 being operable to unlock the latch means L and actuate the same to the open position as seen in FIGS. 3 and 7, :so that the door 2 can be opened as seen in FIG. 3.

More particularly, the latch means L comprises a latch arm 15 having cars 16 which are straddled by upper and lower pairs of vertically spaced lugs 17, and the ear and

lugs

16 and 17, respectively, receive a pivot pin 18, whereby the latch arm 15 is pivotally supported. A coiled torsion spring 19 is disposed about the pivot pin 18 and acts upon the latch arm 15 in a direction tending to close the latch means L, that is, in a counterclockwise direction. The spring 19 has one end 20 which abuts with the body 1, and another end 21 which abuts with a spring anchor lug 22 formed on the lever 15. At its free extremity, the latch arm 15 has upwardly and downwardly projecting

latch lugs

23 and 24, respectively, and a vertical web 25. These

latch lugs

23 and 24 cooperate with

companion latch lugs

26 and 27 which project from the door 2 so as to be engaged by the

latch lugs

22, 23 and 24, as best seen in FIGS. 1 and 4, so that the door is precluded from swinging open until the latch arm 15 is moved in a clockwise direction about the pivot 18. The

lugs

26 and 27 have camming surfaces 28 engageable with arched confronting edge surfaces 29 on the

latch lugs

23 and 24, so that when the door 2 is closed the

companion surfaces

28 and 29 cam the latch arm 15 in a clockwise direction until the

lugs

26 and 27 pass the

latch lugs

23 and 24, at which time the spring 19 will bias the latch arm 15 to the latched position of FIGS. 1, 4 and 5.

The operating means comprises a lever 30 having a handle 31. The lever 30 is pivotally mounted upon a hinge pin 32 which extends through vertically spaced horizontal flanges 33 on the door 2 which project outwardly from the door to provide a space 34 in which the lever 30 is recessed when the elevator is closed, so as to be protected from accidental operation by contact with equipment in the derrick.

The lever 30 comprises a lever section 35 at one side of the pivot pin 32 and having at its free end the handle 31, whereby the lever may be actuated to overcome the normal bias of a coiled torsion spring 37 which is disposed about the pivot pin 32 and at one end engages a vertical side surface of the door 2 and at its other end engages a portion 36 on the lever 30.

Between the pivot pin 32 and the handle 31, the lever section 35 is provided with means engageable with the latch arm to open the latch means I. in response to pivotal movement of the operating means 0 about the pivot pin 32 in a clockwise direction. More particularly, a roller 38 is rotatably mounted upon a pin 39 which extends vertically between a pair of spaced lugs 40 formed on the lever, the roller 38 being engageable with the web 25 of the latch arm 15, as seen in FIGS. 6 and 7, to progressively cam the latch arm 15 to the unlatched position of FIG. 7, from the latched position of FIG. 6.

Further, in accordance with the invention, in order to prevent the latch from inadvertently opening due to vibration or other transient forces, the operating means 0 includes latch locking means in the form of a claw 41 integral with the lever 30, and located at the other side of the pivot pin 32 from the handle 31, so that when the operating means 0 is actuated, the locking claw 41 is first moved to an unlocked position, before the latch 15 is opened. More specifically, the claw 41 includes a recurved or hook-like free end 42 having an internal surface 42a which is adapted to confront an external surface 254 of the latch web 25, as seen in FIG. 5, in planes extending substantially longitudinally of the latch arm 15, so that any tendency of the latch arm 15 to be moved in a clockwise direction about its pivot pin 18 will be resisted, but no camming action will be applied to the claw 41 tending to cause clockwise rotation of the operating means 0 above the pivot pin 32.

In addition, the operating means 0, the claw 41 and the web 25 of the latch arm 15, are arranged and constructed in such a way that the confronting surfaces 42a and 25a on the claw and on the web, respectively, are located at the opposite sides of the pivot 32 from the handle 31, whereby any force tending to inadvertently open the latch induces a counterclockwise force on the lever 30, thereby assisting the spring 37 in holding the lever 30 in the latch locking position, with an internal stop lug 30a of the lever 30 engaging a side wall of the door, as seen in FIG. 5. In this position, moreover, the operating means are shrouded or sheltered in the space 34 between the door flanges 33.

In the use of the device, a workman in the derrick or on the derrick floor need merely grip the handle 31 and pull outwardly thereon to initially release the latch lock claw 41, as seen in FIG. 6, before the roller 38 commences to cam the latch about its pivot pin 18 to the open position, as seen in FIG. 7, at which the

respective latch lugs

23 and 24 are disengaged from the

lugs

26 and 27 on the door 2. The door can then be pulled open to the position of FIG. 3. When the door is to be closed, the camming surfaces 28 leading to the

lugs

26 and 27 on the door 2, engage the latch lug surfaces 29 to pivot the latch arm 15 out of the way, as the

lugs

26 and 27 pass inwardly to a position at which the latch arm can reengage with the door. The closing action obviously requires that the operating means 0 be activated from its normal position, as seen in FIG. 5, so that the claw 41 reengages the web 25. In the present construction, the latch spring 19 is stronger than the latch lock spring 37, so that the operating means is automatically activated.

From the foregoing, it will be apparent that the present invention provides a simple, rugged safety latch for well pipe elevators having few parts, so structurally arranged that the operating means for releasing the latch lock and opening the latch can not be inadvertently operated and are protected against damage or operation by engagement by equipment in the derrick.

I claim:

1. A well pipe elevator comprising: an arcuate body having means engageable by elevator links for supporting the elevator in the hoist apparatus of a derrick, a side door pivotally mounted on said body and forming a circular structure for surrounding a well pipe upon closure of the door, latch means for releasably holding said door closed, said latch means including a latch arm pivoted on said body, spring means biasing said latch arm in a latching direction, and latch arm engaging means on said door, latch operating means on said door for actuating said latch arm to a released position, said latch operating means including a unitary lever pivotally mounted on said door, an operating handle on said lever at one side of the pivotal mounting for said lever, latch locking means on said lever at the other side of the pivotal mounting for said lever, said latch locking means including a hook-like end section on said lever and providing aflocking surface disposed within the curve of said hook-like end section adjacent to the free end thereof, said latch arm having a portion adapted to be opposed by said locking surface, and spring means biasing said lever to a position at which said locking surface is opposed to said portion of said latch arm.

2. A well pipe elevator as defined in claim 1 wherein said door has outstanding flanges between which said lever is pivotally mounted, said lever being wholely recessed between said flanges when in the locking position.

3. A well pipe elevator as defined in claim 1, wherein said lever has a roller revolvably supported between said handle and the pivotal mounting of said lever for engaging and opening said latch arm after movement of said recurved end section to a non-locking position.

4. A well pipe elevator comprising: an arcuate body having means engageable by elevator links for supporting the elevator in the hoist apparatus of a derrick; a side door pivotally mounted on said body and forming with said body a circular structure for surrounding a well pipe upon pivoting of said door into closed position, and, upon pivoting of said door into open position, providing a doorway for the lateral insertion into and the lateral removal from said body of a well pipe; latch means for releasably holding said door in said closed position, said latch means including a lug on said door, a latch arm pivoted on said body and pivotable into engagement with said lug when said door is in closed position for holding said door in said closed position; first spring means biasing said latch arm into engagement with said lug, said latch arm being pivotable to a position released from engagement with said lug to permit said door to pivot to open position; an operating lever; pivot means for mounting said operating lever on said door, said operating lever having a first arm extending in one direction from said pivot means and a second arm unitary with said first arm and extending in a generally opposite direction from said pivot means; an operating handle on said first arm, said first arm being pivotable towards and away from said door to swing said second arm away from and towards said door upon manipulation of said handle; cooperating stop means carried by said first arm and said door and engageable to limit pivotal movement of said first arm towards said door; second spring means biasing said lever to engage said cooperating stop means; latch arm locking means for releasably holding said latch arm in engagement with said lug, said latch arm locking means including an externally facing locking surface on said latch arm and a hook-like end section on said second arm of said operating lever, said hook-like end section providing an internally facing locking surface disposed within the curve of said hook-like end section adjacent to the free end thereof and confronting said externally facing locking surface and engageable thereby, when said cooperating stop means are engaged, to releasably retain said latch arm in engagement with said lug, said internally facing locking surface being moved from confrontation with said externally facing locking surface upon initial pivotal movement of said first arm of said operating lever away from said door and in a direction to disengage said cooperating stop means, thereby to release said latch arm for pivoting to a position released from engagement with said lug; and] said first arm of said operating lever having means engageable with said latch arm for camming it from engagement with said lug upon further pivotal movement of said first arm away from said door, whereby said door can be pivoted to said open position.

5. A well pipe elevator as defined in claim 4, wherein, when said confronting locking surfaces are interengaged, the zone of engagement of said confronting locking surfaces and the zone of engagement of said cooperating stop means are located on opposite sides of said pivot means for mounting said operating lever on said door, and said latch arm and said operating lever are constructed and arranged so that any inadvertent force tending to pivot said latch arm from engagement with said lug is resisted through said operating lever by the concomitant interengagement of said cooperating stop means.

6. A well pipe elevator as defined in claim 4, having cam members on said latch arm and on said hook-like end section that cooperate, as said latch arm is being pivoted into engagement with said lug, to pivot said operating lever into a position in which said internally facing locking surface is in an out-of-the-way position from which it can move into a position confronting said externally facing locking surface upon pivoting of said operating lever in the opposite direction.

7. A well pipe elevator as defined in claim 6, wherein said first spring means is stronger than said second spring means.

8. A well pipe elevator as defined in claim 4, including a pair of outstanding flanges on said side door, said operating lever being positioned between said flanges and being substantially wholl y recessed therebetween when said cooperating stop means are engaged, said pivot means for mounting said operating lever on said door comprising a pivot pin having its opposite ends mounted on said flanges.

Claims

1. A well pipe elevator comprising: an arcuate body having means engageable by elevator links for supporting the elevator in the hoist apparatus of a derrick, a side door pivotally mounted on said body and forming a circular structure for surrounding a well pipe upon closure of the door, latch means for releasably holding said door closed, said latch means including a latch arm pivoted on said body, spring means biasing said latch arm in a latching direction, and latch arm engaging means on said door, latch operating means on said door for actuating said latch arm to a released position, said latch operating means including a unitary lever pivotally mounted on said door, an operating handle on said lever at one side of the pivotal mounting for said lever, latch locking means on said lever at the other side of the pivotal mounting for said lever, said latch locking means including a hook-like end section on said lever and providing a locking surface disposed within the curve of said hook-like end section adjacent to the free end thereof, said latch arm having a portion adapted to be opposed by said locking surface, and spring means biasing said lever to a position at which said locking surface is opposed to said portion of said latch arm.

4. A well pipe elevator comprising: an arcuate body having means engageable by elevator links for supporting the elevator in the hoist apparatus of a derrick; a side door pivotally mounted on said body and forming with said body a circular structure for surrounding a well pipe upon pivoting of said door into closed position, and, upon pivoting of said door into open position, providing a doorway for the lateral insertion into and the lateral removal from said body of a well pipe; latch means for releasably holding said door in said closed position, said latch means including a lug on said door, a latch arm pivoted on said body and pivotable into engagement with said lug when said door is in closed position for holding said door in said closed position; first spring means biasing said latch arm into engagement witH said lug, said latch arm being pivotable to a position released from engagement with said lug to permit said door to pivot to open position; an operating lever; pivot means for mounting said operating lever on said door, said operating lever having a first arm extending in one direction from said pivot means and a second arm unitary with said first arm and extending in a generally opposite direction from said pivot means; an operating handle on said first arm, said first arm being pivotable towards and away from said door to swing said second arm away from and towards said door upon manipulation of said handle; cooperating stop means carried by said first arm and said door and engageable to limit pivotal movement of said first arm towards said door; second spring means biasing said lever to engage said cooperating stop means; latch arm locking means for releasably holding said latch arm in engagement with said lug, said latch arm locking means including an externally facing locking surface on said latch arm and a hook-like end section on said second arm of said operating lever, said hook-like end section providing an internally facing locking surface disposed within the curve of said hook-like end section adjacent to the free end thereof and confronting said externally facing locking surface and engageable thereby, when said cooperating stop means are engaged, to releasably retain said latch arm in engagement with said lug, said internally facing locking surface being moved from confrontation with said externally facing locking surface upon initial pivotal movement of said first arm of said operating lever away from said door and in a direction to disengage said cooperating stop means, thereby to release said latch arm for pivoting to a position released from engagement with said lug; and said first arm of said operating lever having means engageable with said latch arm for camming it from engagement with said lug upon further pivotal movement of said first arm away from said door, whereby said door can be pivoted to said open position.

8. A well pipe elevator as defined in claim 4, including a pair of outstanding flanges on said side door, said operating lever being positioned between said flanges and being substantially wholly recessed therebetween when said cooperating stop means are engaged, said pivot means for mounting said operating lever on said door comprising a pivot pin having its opposite ends mounted on said flanges.