U.S. patent application number 15/293913 was filed with the patent office on 2017-04-20 for passive latch mechanism for a drilling rig mast.
This patent application is currently assigned to Schlumberger Technology Corporation. The applicant listed for this patent is Schlumberger Technology Corporation. Invention is credited to Mark W. Trevithick.
Application Number | 20170107769 15/293913 |
Document ID | / |
Family ID | 58518097 |
Filed Date | 2017-04-20 |
United States Patent
Application |
20170107769 |
Kind Code |
A1 |
Trevithick; Mark W. |
April 20, 2017 |
Passive Latch Mechanism for a Drilling Rig Mast
Abstract
An automatic mast section latching system is disclosed that
provides rapid and safe connection of sequential mast sections
without placing an employee in a lift to complete the task. A slot
flange extends above each mast section for connecting to a pin
section extending below a mast section above it. A first pin and a
second pin extend perpendicularly from each pin flange. A slot is
formed on the slot flange for receiving the first pin. A ramp is
formed on the top of the slot flange. A seat is formed on the ramp
for receiving the second pin.
Inventors: |
Trevithick; Mark W.;
(Cypress, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Schlumberger Technology Corporation |
Sugar Land |
TX |
US |
|
|
Assignee: |
Schlumberger Technology
Corporation
Sugar Land
TX
|
Family ID: |
58518097 |
Appl. No.: |
15/293913 |
Filed: |
October 14, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62242505 |
Oct 16, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 15/003 20130101;
E21B 7/02 20130101; E04H 12/10 20130101; E21B 7/023 20130101; E04H
12/345 20130101 |
International
Class: |
E21B 15/00 20060101
E21B015/00; E04H 12/10 20060101 E04H012/10; E04H 12/34 20060101
E04H012/34; E21B 7/02 20060101 E21B007/02 |
Claims
1. A drilling rig mast comprising: a first mast section; a second
mast section; a slot flange extending beyond an end of the first
mast section; a pin flange extending beyond an end of the second
mast section; a first pin extending outward from the pin flange; a
second pin extending outward from the pin flange; a slot formed on
the slot flange, the slot configured to receive the first pin; a
ramp formed on an end of the slot flange; a radial seat formed on
the ramp, the seat configured to receive the second pin when the
first pin is located in the slot; and, the first mast section
connectable to the second mast section by location of the first pin
in the slot and location of the second pin in the seat.
2. The drilling mast of claim 1, further comprising: the seat
forming a radial relief on the ramp.
3. The drilling mast of claim 2, further comprising: the seat being
non-tangential to the ramp to form a ramp inflection between
them.
4. The drilling mast of claim 2, further comprising: a compression
arc formed on the seat, beginning at the ramp inflection.
5. The drilling mast of claim 4, further comprising: the
compression arc being at least 45 degrees.
6. The drilling mast of claim 1, further comprising: the slot
having a slide and an edge, and a radial cup connecting the slide
to the edge; and, the distance from a center of the cup to a center
of the seat being equal to the distance between the center of the
first pin and the center of the second pin.
7. The drilling mast of claim 6, further comprising: the radial cup
being non-tangential to the edge of the slot to form a slide
inflection between them.
8. The drilling mast of claim 7, further comprising: a tension arc
formed on the cup, beginning at the slide inflection.
9. The drilling mast of claim 8, further comprising: the tension
arc being at least 45 degrees.
10. The drilling mast of claim 4 further comprising: the cup being
non-tangential to the edge.
11. The drilling mast of claim 2 further comprising: the ramp being
inclined in the direction of the slot, at an angle of between 10
and 20 degrees.
12. The drilling mast of claim 3 further comprising: the slide
being inclined in an amount slightly greater than that of the
ramp.
13. The drilling mast of claim 1 further comprising: the second pin
being laterally offset from the first pin by at least the amount by
which the cup center is offset from the seat center.
14. A drilling rig mast comprising: a first mast section having a
front side and opposing rear side, and a top end and an opposing
bottom end; a second mast section having a front side and opposing
rear side, and a top end and opposing bottom end; a slot flange
extending upward from the top end of the rear side of the first
mast section; a pin flange extending downward from the bottom end
of the rear side of the second mast section; a pin extending
outward from the pin flange; a slot formed on the slot flange, the
slot configured to receive the first pin; and, location of the pin
in the slot aligns an opposing pair of pinned connections between
the first and second mast sections on their front side.
15. A method of connecting consecutive sections of a drilling mast,
comprising: pivotally connecting a lower end of a first mast
section to a drilling floor, the first mast section having a slot
flange on an upper end; providing a slot having a cup and a ramp
having a seat on the slot flange; inclining the first mast section
into a position below a horizontal plane; providing a second mast
section having a pin flange on its lower end; providing a first pin
and a second pin on the pin flange; moving the lower end of the
second mast section towards the upper end of the first mast section
until the second pin engages the ramp; raising the inclination of
the first mast section until the first pin moves into the slot cup;
raising the inclination of the first mast section until the second
pin moves into the seat; and, connecting a front side of the first
and second mast sections together.
16. A method of connecting consecutive sections of a drilling mast,
comprising: pivotally connecting a lower end of a first mast
section to a drilling floor; inclining the first mast section into
a position below a horizontal plane; moving a lower end of a second
mast section towards the upper end of the first mast section;
engaging a second pin on a pin flange on the lower end of the
second mast section with a ramp on a slot flange on the upper end
of the first mast section; raising the inclination of the first
mast section until a first pin on the pin flange is positioned in a
cup on the slot flange; raising the inclination of the first mast
section until the second pin is positioned in a seat on the slot
flange; and, connecting a front side of the first and second mast
sections together.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of a related U.S.
Provisional Application Ser. No. 62/242,505 filed Oct. 16, 2015,
entitled PASSIVE LATCH MECHANISM FOR A DRILLING RIG MAST, to Mark
W. Trevithick, the disclosure of which is incorporated by reference
herein in its entirety.
BACKGROUND
[0002] In the exploration of oil, gas and geothermal energy,
drilling operations are used to create boreholes, or wells, in the
earth. Drilling rigs used in subterranean exploration are
transported to the locations where drilling activity is to be
commenced. These locations are often remotely located in rough
terrain. The transportation of such rigs on state highways is
performed in compliance with highway safety laws and clearance
underneath bridges or inside tunnels. Once transported to the
desired location, large rig components are moved from a transport
trailer into engagement with the other components located on the
drilling pad.
[0003] Moving a full-size drilling rig includes disassembly and
reassembly of the substructure and mast. Safety is of paramount
importance. Speed of disassembly and reassembly impact
profitability. Complete disassembly leads to errors and delay in
reassembly. Modern drilling rigs may have two, three, or even four
mast sections for sequential connection and raising above a
substructure.
[0004] The lower mast section is delivered and positioned by truck
into proximity and alignment with the substructure. The front pair
of lower mast section legs is aligned and pin connected to front
shoes on the drill floor. The lower mast section truck then
departs. The lower mast section is connected to the mast raising
cylinders to enable height adjustment of the lower mast section.
This is done, in part, because variations in the terrain
surrounding the drilling rig render alignment difficult. The center
mast section is then delivered and positioned by truck into
proximity and alignment with the upper end of the lower mast
section. At this stage, the four corners of the lower mast and
center mast sections are aligned to permit connection.
[0005] Connection of the front side of the lower mast section to
the center mast section can be accomplished from ground level.
However, connection of the rear side of the lower mast section to
the center mast section involves placing rig personnel in a lift
and raising them over the suspended and unconnected mast sections.
From a position above the unconnected lower and center mast
sections, the rig personnel can help direct their alignment to the
truck driver and operator of the mast raising cylinders to permit
placement of pins into the rear leg connectors.
[0006] There are well-recognized inherent risks associated with
raising personnel above ground and above unconnected structures.
Additional risks are realized when one of the unconnected structure
components is located on a vehicle. Additional risks are realized
when the terrain is uneven and unpaved. It is desirable to reduce
these risks.
[0007] After connection of the center mast section to the lower
mast section, the center mast section truck departs, and the upper
mast section truck arrives. At this stage, the four corners of the
center mast section and upper mast section are aligned to permit
connection. With the mast section now extended further off of the
substructure, mast section alignment may be more difficult. Rig
personnel is again positioned in a lift suspended above the two
unconnected mast sections to complete connection of the rear side
of the center mast section to the upper mast section.
[0008] When the upper mast section is securely connected to the
center mast section, the upper mast truck departs. If the mast is a
three section mast, it is now fully assembled and the assembled
mast is raised vertically above the drill floor. If the mast is a
four section mast, the crown mast section will now arrive on a
crown section truck.
[0009] At this stage, the four corners of the upper mast section
and crown mast section are aligned to permit connection. With the
partially assembled mast section now extended further off of the
substructure, alignment will be even more difficult for the reasons
stated above. Once again, rig personnel is positioned into a lift
suspended above the two unconnected mast sections to complete
connection of the rear side of the upper mast section to the crown
mast section. When connected, the crown section truck departs.
[0010] The fully assembled mast is then raised by pivoting it on
the pin connection to the drill floor with lifting force supplied
by the mast raising cylinders. When fully erect, the rear mast legs
of the lower mast section are pin connected to the rear shoes on
the drill floor.
[0011] It is desirable to have a connection system that reduces
rig-up and rig-down time. It is desirable to have a system that
provides improved alignment and connectivity between sequential
mast sections during rig-up. It is highly desirable to have a
system with a lower risk of accidents.
[0012] In particular, it is desirable to provide a mast latching
system that enables connection of sequential mast sections without
the need to expose personnel to the safety hazards associated with
working from a lift device above large, unconnected sections of a
drilling rig mast.
[0013] The disclosed embodiments provide a novel solution to the
engineering constraints and challenges of providing a rapid, safe,
and reliable connection between mast sections of a drilling
rig.
SUMMARY
[0014] A drilling rig mast system is provided, having a first mast
section and a series connectable second mast section. A slot flange
extends beyond an end of the first mast section. A pin flange
extends beyond an end of the second mast section for engagement
with the slot flange. A first pin extends outward from the pin
flange. A second pin also extends outward from the pin flange.
[0015] A slot is formed on the slot flange and is configured to
receive the first pin. A ramp is formed on the end of the slot
flange and is configured to engage the second pin. A seat is formed
on the ramp of the slot flange. The seat is configured to receive
the second pin when the first pin is located in the slot.
[0016] The first mast section is connectable to the second mast
section by location of the first pin in the slot and location of
the second pin in the pin seat. When the pins are located in the
slot and seat, respectively, the first and second mast sections are
sufficiently connected at the rear side of the mast such that pins
may then be connected by rig personnel on the ground. This method
can then be repeated for each successive section of mast added.
[0017] As will be understood by one of ordinary skill in the art,
the assembly disclosed may be modified and the same advantageous
result obtained. In particular, one of ordinary skill in the art
will recognize that the pin flange and slot flange may be reversed
in orientation as between sequential sections of the mast or other
large truss system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a side view of a drilling rig with the lower mast
section pinned to the drill floor and the center mast section being
attached to the lower mast section and illustrating one embodiment
of the passive mast latch mechanism.
[0019] FIG. 2 is a side view of an embodiment of the slot flange of
the passive mast latch mechanism.
[0020] FIG. 3 is a side view of an embodiment of the pin flange of
the passive mast latch mechanism.
[0021] FIG. 4 is a side view of the pin flange of FIG. 3 engaged
with the slot flange of FIG. 2, and illustrating certain properties
of the engagement of this embodiment.
[0022] FIG. 5 is a side view of a step of the connection method of
an embodiment, illustrating a first mast section having a slot
flange on its upper end. The first mast section is in the proper
angular position for approach by a second mast section having a pin
flange on its lower end.
[0023] FIG. 6 is a side view of another step of the connection
method of an embodiment, illustrating the ramp of the slot flange
impacted by the second pin of the pin flange, and illustrating the
first pin positioned above the slot of the slot flange.
[0024] FIG. 7 is a side view of another step of the connection
method of an embodiment, illustrating the first mast section raised
sufficiently to permit the first pin to engage in the slot.
[0025] FIG. 8 is a side view of another step of the connection
method of an embodiment, illustrating the first mast section raised
sufficiently further to engage the second pin in the seat below the
ramp, and to align the front side of the first and second mast
sections to permit them to be manually pinned together.
[0026] FIG. 9 is a side view of an optional step of the connection
method of an embodiment, illustrating the second mast section
having a slot flange on its upper end. The second mast section is
in the proper angular position for approach by a third mast section
having a pin flange on its lower end.
[0027] FIG. 10 is a side view illustrating an optional step of the
connection method, which is substantially a repeat of the second
method step, illustrated as performed as between the second and
third mast sections.
[0028] FIG. 11 is a side view of an optional step of the connection
method of an embodiment, which is substantially a repeat of the
third method step, illustrated as performed as between the second
and third mast sections.
[0029] FIG. 12 is a side view of an optional step of the connection
method of an embodiment, which is substantially a repeat of the
fourth method step, illustrated as performed as between the second
and third mast sections.
[0030] FIG. 13 is a side view illustrating the first mast section
positioned for connection to the second mast section with the
passive latch system.
[0031] FIG. 14 is a side view illustrating the first and second
mast sections positioned for approach by the third mast
section.
[0032] FIG. 15 is a side view illustrating the first and second
mast sections positioned for connection to the third mast section
with the passive latch system.
[0033] FIG. 16 is a side view illustrating the first, second, and
third mast sections positioned for approach by the fourth mast
section.
[0034] FIG. 17 is a side view illustrating each of the first,
second, third, and fourth mast sections connected in series with an
embodiment of the passive latch system of the present
invention.
[0035] The steps listed above are not inclusive or exclusive of the
numerous other procedures related to the rig-up or rig-down of a
drilling rig. The features and benefits of the disclosed
embodiments will become more readily understood from the following
detailed description and appended claims when read in conjunction
with the accompanying drawings in which like numerals represent
like elements.
[0036] The drawings constitute a part of this specification and
include embodiments that may be embodied in various forms. It is to
be understood that in some instances various aspects of the
embodiments described may be shown exaggerated or enlarged to
facilitate an understanding of the embodiments.
DETAILED DESCRIPTION
[0037] The following description is presented to enable any person
skilled in the art to make and use the disclosed embodiments, and
is provided in the context of a particular application and its
requirements. Various modifications to the disclosed embodiments
will be readily apparent to those skilled in the art, and the
general principles defined herein may be applied to other
embodiments and applications without departing from the spirit and
scope of the present invention. In particular, it will be
recognized the relative positions of the slot flanges and pin
flanges can be reversed to provide the equivalent structure,
function, method, and result of the embodiments disclosed.
[0038] FIG. 1 is a side view of one embodiment of a drilling rig 1.
Drilling rig 1 has an expandable substructure 10. Substructure 10
has a drill floor 12 generally spanning across its top. A pair of
front shoes 14 extends above drill floor 12. A pair of rear shoes
16 extends above drill floor 12. A pair of mast raising cylinders
20 is connected to substructure 10.
[0039] A first ("lower") mast section 100 is provided. First mast
section 100 may be generally rectilinear, having a front side 102
and an opposite rear side 104, as well as a conventionally known
Driller's side (shown) and an opposite Off-Driller's side (not
visible, but opposite to the Driller's side). First mast section
100 has a pair of front legs 106 and a pair of rear legs 108 at its
lower end. First mast section 100 has an opposite upper end
110.
[0040] Front legs 106 of a first mast section 100 are pivotally pin
connected to front shoes 14. Rear legs 108 are pin connectable to
rear shoes 16 upon pivoted erection of first mast section 100 into
a vertical orientation above drill floor 12.
[0041] First mast section 100 is raised into the vertical position
above drill floor 12 by a pair of raising cylinders 20. Raising
cylinders 20 are capable of controlling the angular disposition of
first mast section 100, however, as a person of ordinary skill in
the art of drilling rig design will appreciate, drilling masts are
conventionally raised by one or more pairs of hydraulic cylinders
arranged in various configurations depending upon the rig size,
weight, and design configuration. For example, a pair of boost
cylinders is commonly incorporated. Therefore, as used herein,
"mast raising cylinders" 20 is intended to include any such
combination or configuration of expandable cylinders used to
control the angularity of the individual, partially assembled, and
assembled mast sections relative to the drill floor during assembly
and erection of the mast.
[0042] Referring again to FIG. 1, a pair of conventional pin
connections 120 is provided on front side 102 of first mast section
100, proximate to upper end 110. A pair of slot flanges 500 is
provided on each side (Driller's side and Off-Driller's side) of
upper end 110 of rear side 104 of first mast section 100.
[0043] A second ("center") mast section 200 is provided for series
connection to upper end 110 of first mast section 100. Second mast
section 200 may be generally rectilinear. It has a front side 202
and an opposite rear side 204. Front side 202 and rear side 204 are
separated by a conventionally known Driller's side (shown facing
the page) and an opposite Off-Driller's side (not visible, opposite
to the Driller's side). Second mast section 200 has a lower end 208
and an opposite upper end 210. A pair of pin flanges 600 is
provided on each side (Driller's side and Off-Driller's side) of
lower end 208 of rear side 204 of second mast section 200. A pair
of conventional pin connections 220 is provided on front side 202
of lower end 208 of second mast section 200 for connection to pin
connections 120 on front side 102 of upper end 110 of first mast
section 100. A pair of conventional pin connections 230 may be
provided on front side 202 of upper end 210 of second mast section
200 for connection to another mast section.
[0044] FIG. 2 is a side view of an embodiment of slot flange 500 of
the passive mast latch mechanism. As seen in this view, slot flange
500 has a slot 510, comprising a slide 512, a cup 514, and an edge
516. Cup 514 connects slide 512 to edge 516. In the embodiment
illustrated in FIG. 2, cup 514 is non-tangent to edge 516 at slide
inflection 518. From a center 520, cup 514 has a radius 522 that
extends over an included arc 524. A tension arc 526 is within
included arc 524, terminating at slide inflection 518.
[0045] Also formed on slot flange 500 is an impact ramp 532. A seat
534 is formed at the bottom of impact ramp 532. From a center 540,
seat 534 has a radius 542 that extends over an included arc 544,
terminating at ramp inflection 538. In the embodiment illustrated
in FIG. 2, seat 534 is non-tangent to impact ramp 532 at ramp
inflection 538.
[0046] Also in the embodiment illustrated, impact ramp 532 is
non-parallel to slide 512. In particular, angle 528 of slide 512 is
slightly greater than angle 548 of impact ramp 532. Also in the
embodiment illustrated, center 520 of cup 514 and center 540 of
seat 534 are separated by a distance 550, with center 520 of cup
514 disposed closer to rear surface 104 of first mast section 100
than is center 540 of seat 534.
[0047] FIG. 3 is a side view of one embodiment of a pin flange 600
of the passive mast latch mechanism. In the embodiment illustrated,
pin flange 600 is attached to each side (Driller's side and
Off-Driller's side) of lower end 208 of rear side 204 of a second
mast section 200. These two pin flanges 600 are thus positioned for
engagement with two opposing slot flanges 500 located on the upper
end 110 of rear side 104 of first mast section 100 (See FIG.
1).
[0048] Each pin flange 600 has a first pin 610 and a second pin
620. Pin 610 has a diameter that renders it receivable in cup 514
of slot 510. Pin 620 has a diameter that renders it receivable in
seat 534 at the end of impact ramp 532.
[0049] FIG. 4 is a side view of pin flange 600 of FIG. 3 engaged
with slot flange 500 of FIG. 2, and illustrating certain properties
of the engagement of this embodiment. As represented in FIG. 4, a
tensile force T is present and acting on first pin 610 when
assembled mast sections 100 and 200 are rotated about front shoe 14
connections by lifting cylinders 20 into a vertical position above
drill floor 12. When erect, wind loads create tensile force T at
first pin 610. To tolerate tensile force T without the urge to
disengage, a tension bearing zone is provided along tension arc
526. Tension arc 526 extends to within included arc 524, and
terminates at slide inflection 518. For safety, the included angle
of tension arc 526 should be at least about 35-45 degrees.
[0050] In addition to providing a tension bearing zone, the
location of slide inflection 518 provides resistance to
disengagement of first pin 610 from slot 510 when first pin 610
experiences tensile load T.
[0051] The remainder of included arc 524 resists shear forces S
resulting from the extension of raising cylinders 20 when using the
passive latch mechanism, such as will be described in the third and
fourth method steps below.
[0052] Still referring to FIG. 4, a compressive force C is present
and acting on second pin 620 when the assembled mast sections 100
and 200 are rotated about front shoe 14 connections by lifting
cylinders 20 into a vertical position above drill floor 12. When
erect, the weight of the fully assembled mast and drill string
create compressive force C at second pin 620. To tolerate
compressive force C without the urge to disengage, a compressive
bearing zone is provided along compression arc 546. Compression arc
546 is within included arc 544, and terminates at ramp inflection
538. For safety, the minimum including angle of compression arc 546
is about 35 to 45 degrees.
[0053] In addition to providing a compressive bearing zone, the
location of ramp inflection 538 provides resistance to
disengagement of second pin 620 from cup 534 when second pin 620
experiences compressive force C.
[0054] The remainder of included arc 544 resists shear forces S
resulting from the extension of raising cylinders 20 when using the
passive latch mechanism, such as will be described in the third and
fourth method steps below.
[0055] FIG. 5 is a side view of the first step of the connection
method of an embodiment, illustrating first mast section 100
angularly positioned by manipulation of raising cylinders 20 to
permit approach by a second mast section truck (not shown)
supporting second mast section 200 having pin flange 600 on its
lower end 208.
[0056] FIG. 6 is a side view of the second step of the connection
method of an embodiment, illustrating second mast section 200 moved
into contact with first mast section 100. In this view, second pin
620 has come in contact with impact ramp 532, positioning first pin
610 above slot 510, and preventing further movement of second mast
section 200 in the direction of first mast section 100.
[0057] FIG. 7 is a side view of the third step of the connection
method of an embodiment, illustrating first mast section 100 raised
slightly by raising cylinders 20 in relation to second mast section
200 sufficiently such that first pin 610 moves into slot 510, such
as by sliding along slide 512 or edge 516 or other means, until
first pin 610 has come to rest in cup 514.
[0058] FIG. 8 is a side view of the fourth step of the connection
method of an embodiment, illustrating first mast section 100 raised
slightly further by raising cylinders 20 in relation to second mast
section 200 sufficiently such that second pin 620 is moved into a
position of complementary fit in seat 534. In moving into the
illustrated position, second pin 620 departs from impact ramp 532
as it passes ramp inflection 538. In this position, engagement of
first pin 610 in cup 514 and engagement of second pin 620 in seat
534 aligns pin connection 120 of first mast section 100 with pin
connection 220 of second mast section 200 such that they may be pin
connected by rig personnel. Pinning a connection between front side
102 of first mast section 100 and front side 202 of second mast
section 200 may be performed from the ground, without placing
personnel in an elevated lift basket.
[0059] FIG. 9 is a side view of an optional fifth step of the
connection method of an embodiment. Connected first and second mast
sections 100 and 200 are raised slightly further by raising
cylinders 20 to permit the second mast section truck to be removed
from its position of support of second mast section 200. Connected
first and second mast sections 100 and 200 are then angularly
positioned by manipulation of raising cylinders 20 to permit
approach by a third mast section truck (not shown) supporting a
third ("upper") mast section 300 having pin connection 330 on its
lower end 308.
[0060] FIG. 10 is a side view illustrating an optional sixth step
of the connection method, which is substantially a repeat of the
second method step. In this sixth step, third mast section 300 is
moved into contact with second mast section 200. In this view,
second pin 620 has come in contact with impact ramp 532,
positioning first pin 610 above slot 510, and preventing further
movement of third mast section 300 in the direction of second mast
section 200.
[0061] FIG. 11 is a side view of an optional seventh step of the
connection method of an embodiment, which is substantially a repeat
of the third method step. In this seventh step, connected first and
second mast sections 100 and 200 are raised slightly by raising
cylinders 20 in relation to third mast section 300 sufficiently
such that first pin 610 moves into slot 510, such as by sliding
along slide 512 or edge 516 or other means, until first pin 610 has
come to rest in cup 514.
[0062] FIG. 12 is a side view of an optional eighth step of the
connection method, which is substantially a repeat of the fourth
method step. In this eighth step, connected first and second mast
sections 100 and 200 are raised slightly further by raising
cylinders 20 in relation to third mast section 300 sufficiently
such that second pin 620 is moved into a position of complementary
fit in seat 534. In moving into the illustrated position, second
pin 620 departs from impact ramp 532 as it passes ramp inflection
538 (See FIG. 2). In this position, engagement of first pin 610 in
cup 514 and engagement of second pin 620 in seat 534 aligns pin
connection 230 of second mast section 200 with pin connection 330
of third mast section 300 such that they may be pin connected by
rig personnel. Pinning a connection between front side 202 of
second mast section 200 and front side 302 of third mast section
300 may be performed from the ground, without placing personnel in
an elevated lift basket.
[0063] FIG. 13 is a side view illustrating first mast section 100
positioned for connection to second mast section 200 with an
embodiment of the passive latch system.
[0064] FIG. 14 is a side view illustrating first and second mast
sections (100, 200) positioned for approach by third mast section
300.
[0065] FIG. 15 is a side view illustrating first and second mast
sections (100, 200) positioned for connection to third mast section
(300) with an embodiment of the passive latch system.
[0066] FIG. 16 is a side view illustrating first, second, and third
mast sections (100, 200, 300) positioned for approach by a fourth
("crown") mast section 400.
[0067] FIG. 17 is a side view illustrating each of first, second,
third, and fourth mast sections (100, 200, 300, 400) connected in
series with an embodiment of the passive latch system between each
successive mast section.
[0068] It has thus been illustrated that the presently disclosed
passive latch mechanism provides a mast connection system that is
automated to reduce rig-up and rig-down time. It provides for fast
and automatic alignment and connection of sequential mast sections
without positioning personnel in a lift above disconnected mast
sections for the purposes of directing alignment and installing or
removing pins.
[0069] If used herein, the term "substantially" is intended for
construction as meaning "more so than not."
[0070] It is noted that the embodiments disclosed are illustrative
rather than limiting in nature and that a wide range of variations,
modifications, changes, and substitutions are contemplated in the
foregoing disclosure and, in some instances, some features may be
employed without a corresponding use of the other features. Many
such variations and modifications may be considered desirable by
those skilled in the art based upon a review of the foregoing
detailed description. Accordingly, it is appropriate that the
appended claims be construed broadly and in a manner consistent
with the scope of the disclosed embodiments.
* * * * *