CA2020623A1 - Cushion connector - Google Patents
Cushion connectorInfo
- Publication number
- CA2020623A1 CA2020623A1 CA002020623A CA2020623A CA2020623A1 CA 2020623 A1 CA2020623 A1 CA 2020623A1 CA 002020623 A CA002020623 A CA 002020623A CA 2020623 A CA2020623 A CA 2020623A CA 2020623 A1 CA2020623 A1 CA 2020623A1
- Authority
- CA
- Canada
- Prior art keywords
- drive
- cushion
- connector
- housing
- pin
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000005553 drilling Methods 0.000 abstract description 6
- 230000006835 compression Effects 0.000 description 7
- 238000007906 compression Methods 0.000 description 7
- 230000035939 shock Effects 0.000 description 7
- 229910000831 Steel Inorganic materials 0.000 description 6
- 239000010959 steel Substances 0.000 description 6
- 239000013536 elastomeric material Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 230000004323 axial length Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 229920001971 elastomer Polymers 0.000 description 3
- 239000000806 elastomer Substances 0.000 description 3
- 239000004519 grease Substances 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- 101100310856 Drosophila melanogaster spri gene Proteins 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000001808 coupling effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000036316 preload Effects 0.000 description 1
Landscapes
- Earth Drilling (AREA)
- Percussive Tools And Related Accessories (AREA)
Abstract
- 14 -CUSHION CONNECTOR ABSTRACT OF THE DISCLOSURE A cushion connector used for above ground drilling has pin and box components at opposite ends. A housing extends axially between the pin and box components. A drive spline is operably connected to one of the components and extends outwardly from the axis of the cushion connector. A plurality of drive blocks extend inwardly from the inside diameter of the housing and engage with keyways of the drive spline. Drive lugs connected to the inside of the housing act on the drive blocks and resilient cushion blocks. A spring extends between the pin and box components within the housing and exerts axial force between them. The drive splines are coaxial with the connector and move axially under operation. Cushion blocks are provided between the drive blocks and drive plugs.
Description
CUSHION CONNECTOR ~ `
INTRODUCTION ;
This invention relates to a cushion connector and, more particularly, to a cushion connector used for blast hole above ground drilling.
. ' ~
BACKGROUND OF THB INVENTION
Cushion connectors are u~ed to cushion the shock c.eated by the drill bit during drilling and passed ~ - ' through the drill ~tring or drill steel to the drill head of the rig. Such cushion connectors are known and, in general, act to absorb the drilling shocks by moving to allow a certain amount of movement between the top of the ~; drill string which is connected to the box end of the cushion connector and the drill drive head which is connected to the pin end of the cushion connector.
From that point of similarity, however, the ;~
tools act considerably differently and absorb the shock in :~
~; a variety of different ways. In one connector, a resilient elastomeric material is inserted into the connector between the housing and the pi~ton which moves relative to the housinq and acts principally to absorb ~ ~
compression shocks which are passed from the drill bit to ~ -the drill drivelh~ad.
-A problem with the use of elastomeric material as a compression absorber, however, is that the material inherently has a limited axial elasticity with the result that the stroke available in the connector is limited. It is desirable to have as long a stroke as possible in order ', '"~ ~'' : ~
: - 2 ~ $~
to absorb the shocks from the drill bit with maximum efficiency.
A further disadvantage with known cushion connectors is that the drive splines do not act within the axial length of the springs. Rather, the springs are located above or below the drive splines. Such a confi~uration results in an increased axial length for the cushion connector which is undesirable when it is preferred to keep the axial length to a minimum for more convenient operating characteristics.
SUMMARY OF THE INVENTION
According to one aspect of the invention, there -~
is provided a cushion connector comprising a pin component at one end of said connector, a box component at the opposite end of said connector, a housing extending ~ ~-between and connected to one of said pin and box components, a piston movable within said housing and connected to the other of said pin and box components, a drive spline extending outwardly from the axis of said piston, at least one drive lug extending inwardly from said housing, a drive block between said housing and said 25 piston, and being engageable with said drive spline and a ~ ~`
spring acting between said pin and box components, said drive spline3 being coaxial with said spring and operable to move axially within said drive blocks.
.. : .,;,.. .;
,, , ;.;.::
BRIEF DESCRIPT~QN OF THE SEVERA~ VIEWS OF THE DRAWINGS -A specific embodiment of the invention will now be described, by way of example only, with the use of drawings in which~
::
INTRODUCTION ;
This invention relates to a cushion connector and, more particularly, to a cushion connector used for blast hole above ground drilling.
. ' ~
BACKGROUND OF THB INVENTION
Cushion connectors are u~ed to cushion the shock c.eated by the drill bit during drilling and passed ~ - ' through the drill ~tring or drill steel to the drill head of the rig. Such cushion connectors are known and, in general, act to absorb the drilling shocks by moving to allow a certain amount of movement between the top of the ~; drill string which is connected to the box end of the cushion connector and the drill drive head which is connected to the pin end of the cushion connector.
From that point of similarity, however, the ;~
tools act considerably differently and absorb the shock in :~
~; a variety of different ways. In one connector, a resilient elastomeric material is inserted into the connector between the housing and the pi~ton which moves relative to the housinq and acts principally to absorb ~ ~
compression shocks which are passed from the drill bit to ~ -the drill drivelh~ad.
-A problem with the use of elastomeric material as a compression absorber, however, is that the material inherently has a limited axial elasticity with the result that the stroke available in the connector is limited. It is desirable to have as long a stroke as possible in order ', '"~ ~'' : ~
: - 2 ~ $~
to absorb the shocks from the drill bit with maximum efficiency.
A further disadvantage with known cushion connectors is that the drive splines do not act within the axial length of the springs. Rather, the springs are located above or below the drive splines. Such a confi~uration results in an increased axial length for the cushion connector which is undesirable when it is preferred to keep the axial length to a minimum for more convenient operating characteristics.
SUMMARY OF THE INVENTION
According to one aspect of the invention, there -~
is provided a cushion connector comprising a pin component at one end of said connector, a box component at the opposite end of said connector, a housing extending ~ ~-between and connected to one of said pin and box components, a piston movable within said housing and connected to the other of said pin and box components, a drive spline extending outwardly from the axis of said piston, at least one drive lug extending inwardly from said housing, a drive block between said housing and said 25 piston, and being engageable with said drive spline and a ~ ~`
spring acting between said pin and box components, said drive spline3 being coaxial with said spring and operable to move axially within said drive blocks.
.. : .,;,.. .;
,, , ;.;.::
BRIEF DESCRIPT~QN OF THE SEVERA~ VIEWS OF THE DRAWINGS -A specific embodiment of the invention will now be described, by way of example only, with the use of drawings in which~
::
2 ~ 2 ~
- 3 - ~ .
Figure 1 is a sectional side view of the cushion connector according to the invention;
Figure 2 i~ a sectional view taken along the plane II-II of Figure 1;
'':: :` ,` `'.':', Figure 3 is an isometric view of a single one of ;~
the cushion blocks; and ~0 Figure 4 is a sectional view of a further embodiment of the invention.
DESCRIPTION OF SPECIFIC EMBOD:EMEN~ ~;:
~ ~.'. '., '.`' Reference i8 now made to the drawings and, in .:~
: particular, to Figure 1 where a cushion connector according to the invention is generally illustrated at 10. ~ -It comprises a pin component 11 at one end and a box component 12 located at the opposite end of the cushion connector 10.
:, ::,~ ..,:
A housing 13 extends axially from the box ;.;~
component 12 and a cap 14 is connected to the housing 13 on the pin end with cap screws 20 located about the : :
: . 25 periphery of the cap 14. A piston 21 extends from the pin ~
: component 11 and is movable with the pin component 11 ;::
relative to the housing 13 and box end 12. The piston 21 : ~:
includes a plurality of,drive splines 22 (Figure 2) ..
extending outwardly from the axis 23 of the piston 21, the 30 drive splinefi 22 engaging with complementary drive blocks : . .
: 24 and being movable relative thereto, the drive blocks 24 extending inwardly from the housing 13 as best seen in ~ :
Figure 2 and which have an arc shaped outer periphery as illustrated in Figure 1. Two sets of Belleville or disc ~prings 30, 60, having different outside diameters, are mounted in a recess provided between the piston 21 and a - 2 ~ 2 }~
Figure 1 is a sectional side view of the cushion connector according to the invention;
Figure 2 i~ a sectional view taken along the plane II-II of Figure 1;
'':: :` ,` `'.':', Figure 3 is an isometric view of a single one of ;~
the cushion blocks; and ~0 Figure 4 is a sectional view of a further embodiment of the invention.
DESCRIPTION OF SPECIFIC EMBOD:EMEN~ ~;:
~ ~.'. '., '.`' Reference i8 now made to the drawings and, in .:~
: particular, to Figure 1 where a cushion connector according to the invention is generally illustrated at 10. ~ -It comprises a pin component 11 at one end and a box component 12 located at the opposite end of the cushion connector 10.
:, ::,~ ..,:
A housing 13 extends axially from the box ;.;~
component 12 and a cap 14 is connected to the housing 13 on the pin end with cap screws 20 located about the : :
: . 25 periphery of the cap 14. A piston 21 extends from the pin ~
: component 11 and is movable with the pin component 11 ;::
relative to the housing 13 and box end 12. The piston 21 : ~:
includes a plurality of,drive splines 22 (Figure 2) ..
extending outwardly from the axis 23 of the piston 21, the 30 drive splinefi 22 engaging with complementary drive blocks : . .
: 24 and being movable relative thereto, the drive blocks 24 extending inwardly from the housing 13 as best seen in ~ :
Figure 2 and which have an arc shaped outer periphery as illustrated in Figure 1. Two sets of Belleville or disc ~prings 30, 60, having different outside diameters, are mounted in a recess provided between the piston 21 and a - 2 ~ 2 }~
- 4 - :
skirt 31 in respective cylindrical rece~ses 36, 35. The two sets of disc springs 30, 60 extend between the pin component 11 and the box component 12 as is seen in Figure Piston 21 has an integral extension 61 which extends axially into the box component 12. Extension 61 ,~
maintains annular alignment between the pin and box components 11, 12, respectively, and is permitted a degree of radial movement by cushion 16 which is ~ounted within the box end 12 as illu~trated.
The use of the disc springs 30 having a larger diameter than the diameter of disc springs 60 is permitted 15 by the use of the skirt 31 which has a larger internal ,~
diameter at its end furthest removed from the pin ~: component 11. The increased diameter of the second set of ,~
disc springs 30 allows a longer stroke over a given length which allows the cushion connector 10 to be shorter than ,~
20 otherwise would be required. ,`~
The relative axial movement of the pin component "". ,~ ,~
~: 11 relative to the box component 12 is limited by the :'':" -'.' drive splines 22. Skirt 31 has an additional function in 2S preventing the migration of the cushion blocks 70 inwardly~'~,;, and away ~rom their po~ltion between the drive lugs 71 and . `','',':' the drive blocks 24 as ~et out hereafter. A wear and:,' ,'',~
corros,ion resistant sleeve 63 i8 mounted about the distant, periphery of the extension 61. ~,,:~:"
Guide rings 50 and wiper seals 51 are mounted between the box end 12 and the extension 61 of piston 21.
Likewise, a guide ring 52 and a wiper seal 53 are mounted between the cap 14 and the piston 21. ~ , ':
~, ~2~ 3 ~ ~ ~
An elastomer back up cushion 63 (Figure 2) is `~
connected to each of the drive blocks 24 with screws 64.
Elastomer cushion blocks 70 (also illustrated in Figure 3) ;
are mounted between each drive block 24 and the inwardly extending lugs 71 which are integral with housing 13. The cushion blocks 70 contact the faces of the drive blocks 24 and lugs 71 in a surface contacting area distributed over a significant quantity of the surface area of the face portion of both the drive blocks 24 and the lugs 71 and extend axially a distance between the upper and lower surfaces 34, 41, of the cap 14 and box component 12, respectively. As illustrated in Figure 1, the cushion ~
blocXs 70 are compressed when the cushion connector 10 is ~ ;
assembled as will be described in greater detail.
High radial loads are imposed on the cover plate or cap 14 by the piston 21. This is so because it is contemplated the interaction between the drill drive head ;
(not shown) and the rotating drill steel (not shown) 20 connected to the cushion connector 10 attempts to use the ; ;~`~
cushion connector 10 as a ball ~oint in an attempt to accommodate bent or flexing drill steel. Such radial loads will, therefore, act between cap 14 and housing 13 and tend to loosen the cap screws 20 with resulting damage to the mating surfaces.
. :,' . . ..
To avoid or significantly reduce this condition, a conical type interference fit is provided between the cap 14 and the housing 13 in the area 74 (Figure 1). The use of the cap screws 20 to pull the cap 14 axially into the housing 13 utilizing the interference fit between the two components results in a preload or residual force or stress which must be overcome. Thus, any relative movement between the cap 14 and the housing 11 will be significantly reduced or eliminated entirely with the ,~ . -, ,: -~ , ' . ' . .: : ' . . ' : ,: ., : .
2 ~ 2 ~
result that the cap screws 20 will remain tightly fastened.
As the cap screws 20 are tightened, the cushion blocks 70 are compressed axially between the lower and upper surfaces 34, 41, respectively. This causes the cushion blocks 70 to expand at their girth to not only occupy the initial clearance space but to also be compressed between the lugs 71 and drive blocks 24.
,~ : ' OPERATION
The cushion connector lo will be initially asæembled by having the box component 12 in the lowermost 15 position with the axis 23 of the cushion connector 10 ;~
being vertical. The housing 13 will be open with the cap 14 not yet being attached.
The cushion blocks 70 are of a dimension such that when they are positioned between the drive lugs 71 and the drive blocks 24, sufficient clearance is available to permit the drive ~locks 24 to slide around the inside of housing 13 a limited angular amount such that the drive blocks 24 are free to align with and permit insertion of the drive splines 22 into the respective keyway~ 64 in the drive blocks 24.
The disc spri~gs 30, 60 will then be pasitioned in recesses 35, 36.
The cap 14 which has guide ring 52 and the wiper seal 53 previously inserted i8 then fastened securely to the housing 13 using the cap screws 20.
The compression of the cushion blocks 70 will increase as the torque between the pin and box components -- 7 ~
11, 12 is increased. Thus, the cushion blocks 70 achieve a preloaded coupling effect which transmits torque and reduces the torsional shock transmission from the drill string to the drill head as described further hereafter.
A fitting 15 is provided to allow for grease insertion for lubricating the cushion connector 10. The grease is routed through the fitting 15 between the inside of the disc springs 30, 60 and the outside of the lo extension or wash pipe 61 through hole 63 and into the drive block keyways 64 and spline æliding fit areas. The excess of the grease exits through relief fitting 73. -The shape of the cushion blocks 70 is illustrate`d in Figure 3. The width of the block 70 is greatest at its center point. This ensures that the initial contact area between the cushion blocks 70 separating the drive blocks 24 and the lugs 71 occurs over a small area when the cover plate 14 expands the girth of the cushion blocks 70 during assembly.
~ .
The thickness of each cushion block 70 ;~
corresponds over its length to the annular space between the outside diameter of piston 21 and the interior diameter of housing 13 and they are therefore prevented from expanding radially. When the elastomeric material from which the blocks 70 are made is compressed, the material will change in~shape but not in vqiume. Since changes to the height and thickness of the cushion blocks 70 are limited by the surrounding metal parts of the connector 10, any change in shape to accommodate the reduced width, while maintaining a constant volume, must ~ -take place in the areas not confined by the metal and inflexible parts of the connector 10.
''. :..''.
AS compression of the blocks increases with increasing torque transmission by the connector 10 the area not confined by contact with the metal parts decreases and more compressive force is required to change ~ ~ -5 the shape of the blocks. That is, the resistance of the ;~
blocks 70 to compression of their width increases at an escalating rate when compared to a unit amount of compression. The actual relationship is determined by the hardness of the elastomeric material from which the cushion blocks are made and the shape of the curved edges of the cushion blocks. Thus the rate of torsional -stiffness increase of the connector can be determined by the material properties and shape of the cushion blocks 70.
-~
The cushion connector lo is then connected with the pin end 11 to the drill drive head (not illustrated) and the drill steel (not illustrated) is connected to the box end 12 of the cushion connector 10. Drilling now commences.
As the compression shocks created by the action of the drill bit on the ground formation are transferred through the drill steel, the cushion connector 10 will alternatively compre~s the springs and extend the springs 30, 60. The tor~ion created by the drill head on the pin end 11 of the cushion connector 10 will be transferred through the drive splines 22 to the drive blocks 24.
The torque will be transmitted by the drive blocks 24 to the cushion blocks 70 which will absorb the torsional excesses and distribute the torque more uniformly. The torque will then be transmitted to the lugs 71 of the housing 13 and thence to the drill steel through box component 12.
: ::.~ ''''.:.`
', ~"~ -,;
_ 9 _ As compared to the Figure 4 embodiment described -~
hereafter, the Figure 1 embodiment allows a larger diameter for some of the Belleville or disc springs. The springs 30, 60 have a common in~ide diameter and spring 5 rate but the cprings 30 have a larger outside diameter,;; -;;
being at a location which makes the increased volume available.
; ,.;.,: . ~, .. . .
The larger diameter disc springs 30 provide a longer stroke per spring which allows the overall length of the cushion connector $0 to be shorter. The larger ~
volume of spring material results in lower spring stresses -and, hence, a longer fatigue life for the springs 30.
~: . . .
The extension or skirt 31 of piston 21 in Figure ~;
1 prevents the elastomer cushion blocks 70 from being deformed into the space beneath the end of the drive area and thereby interfering with the axial movement of the connector lo.
An additional embodiment of the cushion connector 10 according to the invention i8 illustrated in Figure 4 wherein like numerals represent similar elements as those illustrated in the embodiment of Figures 1 and 2.
In thi~ embodiment, the extension 61 of the Figure 1 embodiment is replaced with a wear and corrosion resistant washpipe 80 w!hich i8 not integral with either the pin or box components 11, 12 but which is, rather, a separate piece and which is mounted between two collars 81, 82, collar 81 being removably mounted within box end -12 and collar 82 being removably mounted within pin end -ll. The washpipe 80 allows for limited angular movement betwesn the pin and box components 11, 12 and is 35 mai~tained in an axial position within the connector 10 by `~
the reduced bore 85 of the pin end 11 and the retaining . ~ -' P3 ~
- 10 ~
~ '"' ~ 'f''' ring 84. The washpipe 80 can be removed without disassembly of the connector 10 by removing the retaining ring 84.
The outside diameter of the disc springs 30 in :~;` . .
this embodiment are identical which i different from the springs 30, 60 of the Figure 1 embodiment as earlier set out. This is so because the piston 21 must take some :~
force resulting from angular misalignment between the box ~ :
lo and pin ends 12, 11, respectively, and, therefore, it being of a size having increased load bearing capacity with the result that there is a smaller inside diameter of the piston 21 available to house the disc springs 30.
Wiper ring~ 83, 84 are provided which act as seals between the collars 81, 82, the washpipe 80 and the pin and box components 11, 12.
. ~
It is contemplated that the cushion connector may readily be used for raise boring in addition to above~
ground drilling. In this event, the teachings of the invention would apply.
Although the seals 83, 84 are illustrated in the 25 Figure 4 embodiment as being in~erted in recesses ln the ~ ;
collars 81, 82, it is contemplated that the seals 83, 84 could be mounted in the washpipe 80. In this event, seals 83, 84 could be replaced by.removing the washpipe 80 which can be conveniently accomplished by simply removing the retaining ring 84 and retrieving the washpipe 80 together with the seals 83, 84 from the box end 12 without otherwise disassembling the cushion connector 10.
Many further modifications to the apparatus 35 described and illustrated will readily occur to those -~
skilled in the art to which the invention relates and the : ~ 3 specific embodiments set forth herein should be considered as illustrative of the invention only and not as limiting . .;
its scope as defined in accordance with the accompanying claims. :~
:.
,`' :,',;.
', ""'~
:;
, , ~ -:,, . ' 2~
:, ,'' .:~' :.
,' ,.-` :;:, , ., : ~` '.'',' ..
:., ~. ~ :,:
, : , ~ 35
skirt 31 in respective cylindrical rece~ses 36, 35. The two sets of disc springs 30, 60 extend between the pin component 11 and the box component 12 as is seen in Figure Piston 21 has an integral extension 61 which extends axially into the box component 12. Extension 61 ,~
maintains annular alignment between the pin and box components 11, 12, respectively, and is permitted a degree of radial movement by cushion 16 which is ~ounted within the box end 12 as illu~trated.
The use of the disc springs 30 having a larger diameter than the diameter of disc springs 60 is permitted 15 by the use of the skirt 31 which has a larger internal ,~
diameter at its end furthest removed from the pin ~: component 11. The increased diameter of the second set of ,~
disc springs 30 allows a longer stroke over a given length which allows the cushion connector 10 to be shorter than ,~
20 otherwise would be required. ,`~
The relative axial movement of the pin component "". ,~ ,~
~: 11 relative to the box component 12 is limited by the :'':" -'.' drive splines 22. Skirt 31 has an additional function in 2S preventing the migration of the cushion blocks 70 inwardly~'~,;, and away ~rom their po~ltion between the drive lugs 71 and . `','',':' the drive blocks 24 as ~et out hereafter. A wear and:,' ,'',~
corros,ion resistant sleeve 63 i8 mounted about the distant, periphery of the extension 61. ~,,:~:"
Guide rings 50 and wiper seals 51 are mounted between the box end 12 and the extension 61 of piston 21.
Likewise, a guide ring 52 and a wiper seal 53 are mounted between the cap 14 and the piston 21. ~ , ':
~, ~2~ 3 ~ ~ ~
An elastomer back up cushion 63 (Figure 2) is `~
connected to each of the drive blocks 24 with screws 64.
Elastomer cushion blocks 70 (also illustrated in Figure 3) ;
are mounted between each drive block 24 and the inwardly extending lugs 71 which are integral with housing 13. The cushion blocks 70 contact the faces of the drive blocks 24 and lugs 71 in a surface contacting area distributed over a significant quantity of the surface area of the face portion of both the drive blocks 24 and the lugs 71 and extend axially a distance between the upper and lower surfaces 34, 41, of the cap 14 and box component 12, respectively. As illustrated in Figure 1, the cushion ~
blocXs 70 are compressed when the cushion connector 10 is ~ ;
assembled as will be described in greater detail.
High radial loads are imposed on the cover plate or cap 14 by the piston 21. This is so because it is contemplated the interaction between the drill drive head ;
(not shown) and the rotating drill steel (not shown) 20 connected to the cushion connector 10 attempts to use the ; ;~`~
cushion connector 10 as a ball ~oint in an attempt to accommodate bent or flexing drill steel. Such radial loads will, therefore, act between cap 14 and housing 13 and tend to loosen the cap screws 20 with resulting damage to the mating surfaces.
. :,' . . ..
To avoid or significantly reduce this condition, a conical type interference fit is provided between the cap 14 and the housing 13 in the area 74 (Figure 1). The use of the cap screws 20 to pull the cap 14 axially into the housing 13 utilizing the interference fit between the two components results in a preload or residual force or stress which must be overcome. Thus, any relative movement between the cap 14 and the housing 11 will be significantly reduced or eliminated entirely with the ,~ . -, ,: -~ , ' . ' . .: : ' . . ' : ,: ., : .
2 ~ 2 ~
result that the cap screws 20 will remain tightly fastened.
As the cap screws 20 are tightened, the cushion blocks 70 are compressed axially between the lower and upper surfaces 34, 41, respectively. This causes the cushion blocks 70 to expand at their girth to not only occupy the initial clearance space but to also be compressed between the lugs 71 and drive blocks 24.
,~ : ' OPERATION
The cushion connector lo will be initially asæembled by having the box component 12 in the lowermost 15 position with the axis 23 of the cushion connector 10 ;~
being vertical. The housing 13 will be open with the cap 14 not yet being attached.
The cushion blocks 70 are of a dimension such that when they are positioned between the drive lugs 71 and the drive blocks 24, sufficient clearance is available to permit the drive ~locks 24 to slide around the inside of housing 13 a limited angular amount such that the drive blocks 24 are free to align with and permit insertion of the drive splines 22 into the respective keyway~ 64 in the drive blocks 24.
The disc spri~gs 30, 60 will then be pasitioned in recesses 35, 36.
The cap 14 which has guide ring 52 and the wiper seal 53 previously inserted i8 then fastened securely to the housing 13 using the cap screws 20.
The compression of the cushion blocks 70 will increase as the torque between the pin and box components -- 7 ~
11, 12 is increased. Thus, the cushion blocks 70 achieve a preloaded coupling effect which transmits torque and reduces the torsional shock transmission from the drill string to the drill head as described further hereafter.
A fitting 15 is provided to allow for grease insertion for lubricating the cushion connector 10. The grease is routed through the fitting 15 between the inside of the disc springs 30, 60 and the outside of the lo extension or wash pipe 61 through hole 63 and into the drive block keyways 64 and spline æliding fit areas. The excess of the grease exits through relief fitting 73. -The shape of the cushion blocks 70 is illustrate`d in Figure 3. The width of the block 70 is greatest at its center point. This ensures that the initial contact area between the cushion blocks 70 separating the drive blocks 24 and the lugs 71 occurs over a small area when the cover plate 14 expands the girth of the cushion blocks 70 during assembly.
~ .
The thickness of each cushion block 70 ;~
corresponds over its length to the annular space between the outside diameter of piston 21 and the interior diameter of housing 13 and they are therefore prevented from expanding radially. When the elastomeric material from which the blocks 70 are made is compressed, the material will change in~shape but not in vqiume. Since changes to the height and thickness of the cushion blocks 70 are limited by the surrounding metal parts of the connector 10, any change in shape to accommodate the reduced width, while maintaining a constant volume, must ~ -take place in the areas not confined by the metal and inflexible parts of the connector 10.
''. :..''.
AS compression of the blocks increases with increasing torque transmission by the connector 10 the area not confined by contact with the metal parts decreases and more compressive force is required to change ~ ~ -5 the shape of the blocks. That is, the resistance of the ;~
blocks 70 to compression of their width increases at an escalating rate when compared to a unit amount of compression. The actual relationship is determined by the hardness of the elastomeric material from which the cushion blocks are made and the shape of the curved edges of the cushion blocks. Thus the rate of torsional -stiffness increase of the connector can be determined by the material properties and shape of the cushion blocks 70.
-~
The cushion connector lo is then connected with the pin end 11 to the drill drive head (not illustrated) and the drill steel (not illustrated) is connected to the box end 12 of the cushion connector 10. Drilling now commences.
As the compression shocks created by the action of the drill bit on the ground formation are transferred through the drill steel, the cushion connector 10 will alternatively compre~s the springs and extend the springs 30, 60. The tor~ion created by the drill head on the pin end 11 of the cushion connector 10 will be transferred through the drive splines 22 to the drive blocks 24.
The torque will be transmitted by the drive blocks 24 to the cushion blocks 70 which will absorb the torsional excesses and distribute the torque more uniformly. The torque will then be transmitted to the lugs 71 of the housing 13 and thence to the drill steel through box component 12.
: ::.~ ''''.:.`
', ~"~ -,;
_ 9 _ As compared to the Figure 4 embodiment described -~
hereafter, the Figure 1 embodiment allows a larger diameter for some of the Belleville or disc springs. The springs 30, 60 have a common in~ide diameter and spring 5 rate but the cprings 30 have a larger outside diameter,;; -;;
being at a location which makes the increased volume available.
; ,.;.,: . ~, .. . .
The larger diameter disc springs 30 provide a longer stroke per spring which allows the overall length of the cushion connector $0 to be shorter. The larger ~
volume of spring material results in lower spring stresses -and, hence, a longer fatigue life for the springs 30.
~: . . .
The extension or skirt 31 of piston 21 in Figure ~;
1 prevents the elastomer cushion blocks 70 from being deformed into the space beneath the end of the drive area and thereby interfering with the axial movement of the connector lo.
An additional embodiment of the cushion connector 10 according to the invention i8 illustrated in Figure 4 wherein like numerals represent similar elements as those illustrated in the embodiment of Figures 1 and 2.
In thi~ embodiment, the extension 61 of the Figure 1 embodiment is replaced with a wear and corrosion resistant washpipe 80 w!hich i8 not integral with either the pin or box components 11, 12 but which is, rather, a separate piece and which is mounted between two collars 81, 82, collar 81 being removably mounted within box end -12 and collar 82 being removably mounted within pin end -ll. The washpipe 80 allows for limited angular movement betwesn the pin and box components 11, 12 and is 35 mai~tained in an axial position within the connector 10 by `~
the reduced bore 85 of the pin end 11 and the retaining . ~ -' P3 ~
- 10 ~
~ '"' ~ 'f''' ring 84. The washpipe 80 can be removed without disassembly of the connector 10 by removing the retaining ring 84.
The outside diameter of the disc springs 30 in :~;` . .
this embodiment are identical which i different from the springs 30, 60 of the Figure 1 embodiment as earlier set out. This is so because the piston 21 must take some :~
force resulting from angular misalignment between the box ~ :
lo and pin ends 12, 11, respectively, and, therefore, it being of a size having increased load bearing capacity with the result that there is a smaller inside diameter of the piston 21 available to house the disc springs 30.
Wiper ring~ 83, 84 are provided which act as seals between the collars 81, 82, the washpipe 80 and the pin and box components 11, 12.
. ~
It is contemplated that the cushion connector may readily be used for raise boring in addition to above~
ground drilling. In this event, the teachings of the invention would apply.
Although the seals 83, 84 are illustrated in the 25 Figure 4 embodiment as being in~erted in recesses ln the ~ ;
collars 81, 82, it is contemplated that the seals 83, 84 could be mounted in the washpipe 80. In this event, seals 83, 84 could be replaced by.removing the washpipe 80 which can be conveniently accomplished by simply removing the retaining ring 84 and retrieving the washpipe 80 together with the seals 83, 84 from the box end 12 without otherwise disassembling the cushion connector 10.
Many further modifications to the apparatus 35 described and illustrated will readily occur to those -~
skilled in the art to which the invention relates and the : ~ 3 specific embodiments set forth herein should be considered as illustrative of the invention only and not as limiting . .;
its scope as defined in accordance with the accompanying claims. :~
:.
,`' :,',;.
', ""'~
:;
, , ~ -:,, . ' 2~
:, ,'' .:~' :.
,' ,.-` :;:, , ., : ~` '.'',' ..
:., ~. ~ :,:
, : , ~ 35
Claims (8)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A cushion connector comprising a pin component at one end of said connector, a box component at the opposite end of said connector, a housing extending between and connected to one of said pin and box components, a piston movable within said housing and connected to the other of said pin and box components, a drive spline extending outwardly from the axis of said piston, at least one drive lug extending inwardly from said housing, a drive block between said housing and said piston, and being engageable with said drive spline and a spring acting between said pin and box components, said drive splines being coaxial with said spring and operable to move axially within said drive blocks.
2. A cushion connector as in claim 1 and further comprising a cushion block between said drive lug and said drive block.
3. A cushion connector as in claim 2 and further comprising a cap mounted to said housing between said housing and the outside diameter of said pin or box component.
4. A cushion connector as in claim 3 wherein said spring is a disc spring.
5. A cushion connector as in claim 4 wherein said drive block contacts said cushion block.
6. A cushion connector as in claim 5 wherein said drive spline is operably connected to said piston.
7. A cushion connector as in claim 1 or 2 wherein said drive spline extends outwardly from the axis of said piston at a position within the axial working area of said spring.
8. A cushion connector as in claim 7 wherein said drive spline has an inside diameter which is larger than the outside diameter of said spring.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002020623A CA2020623A1 (en) | 1990-07-06 | 1990-07-06 | Cushion connector |
| AU67947/90A AU649636B2 (en) | 1990-07-06 | 1990-12-11 | Cushion connector |
| US07/921,989 US5224898A (en) | 1990-07-06 | 1992-08-03 | Cushion connector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002020623A CA2020623A1 (en) | 1990-07-06 | 1990-07-06 | Cushion connector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2020623A1 true CA2020623A1 (en) | 1992-01-07 |
Family
ID=4145422
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002020623A Abandoned CA2020623A1 (en) | 1990-07-06 | 1990-07-06 | Cushion connector |
Country Status (2)
| Country | Link |
|---|---|
| AU (1) | AU649636B2 (en) |
| CA (1) | CA2020623A1 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4139994A (en) * | 1977-03-23 | 1979-02-20 | Smith International, Inc. | Vibration isolator |
| US4844181A (en) * | 1988-08-19 | 1989-07-04 | Grey Bassinger | Floating sub |
-
1990
- 1990-07-06 CA CA002020623A patent/CA2020623A1/en not_active Abandoned
- 1990-12-11 AU AU67947/90A patent/AU649636B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| AU649636B2 (en) | 1994-06-02 |
| AU6794790A (en) | 1992-01-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5224898A (en) | Cushion connector | |
| US4162619A (en) | Drill string shock sub | |
| US6808455B1 (en) | Torsional shock absorber for a drill string | |
| US3947009A (en) | Drill shock absorber | |
| US5267905A (en) | Sealed downhole motor drive shaft universal joint assembly | |
| US6308940B1 (en) | Rotary and longitudinal shock absorber for drilling | |
| US4246765A (en) | Shock absorbing subassembly | |
| US6105969A (en) | Track joint sealing assembly for sealing a track joint in a track chain | |
| US3406537A (en) | Shock absorbing subassembly | |
| US8205691B2 (en) | Downhole vibration dampener | |
| US3884051A (en) | Bearing structure for telescoping well tool | |
| GB2024284A (en) | Drill string shock absorber | |
| US4600062A (en) | Shock absorbing drilling tool | |
| CN112983254B (en) | Screw drilling tool for directional drilling and workover | |
| CA1219855A (en) | Floating cushion sub | |
| EA001702B1 (en) | Downhole motor assembly | |
| US3774731A (en) | Vibration damper | |
| GB2085550A (en) | Articulated coupling | |
| CA2020623A1 (en) | Cushion connector | |
| CA2039535C (en) | Cushion connector | |
| CA1037464A (en) | Drilling string shock-absorbing tool | |
| NO325426B1 (en) | Pressure bearing for a tool at the bottom of the well | |
| CA1206998A (en) | Journal bearing | |
| CN114622837A (en) | Well drilling bumper shock absorber and drilling tool combination with prevent falling function | |
| US4323128A (en) | Spring adjustment system for drill string tool |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 19930106 |