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Патент USA US2124692

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July 26, 1938-
G. F. FERMIER ET AL
2,124,692
CASING HOOK
Filed June 20, 1956
3 Sheets-Sheet l
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July 26, 1938.
G. F. FERMIER ET AL
2,124,692
CAS ING HOOK
Filed June 20, 1936
5 Sheets-Sheet 2
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July 26, 1938.
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G. F. FERMIER ET AL
,692
CASING HOOK
Filed June 20, 1936
3 Sheets-Sheet 3
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2,124,692
UN’ITED STATES PATENT OFFICE
2,124,692
CASING HOOK
George F. Fermier and John C. Stokes, Houston,
Tex., assignors to Reed Roller Bit Company,
Houston, Tex., a corporation oi’ Texas
Application June 20, 1936, Serial No. 86,255
18 Claims.
This invention relates to that type of hooks
customarily employed in the construction and
operation of oil and gas wells for supporting the
casing or drill pipe employed during the drilling
operation.
This invention has to do particularly with a
resilient hook which will effectively support the
weight of a portion of a drill pipe being unscrewed
and which will lift such portion away from the
part from which it is disconnected as soon as the
threads are disengaged.
Hooks of this type are commonly used in putting
in or pulling well casings o1' drill stems, to support
a section of the casing while it is being unscrewed
from the other sections. The separation of the
sections is effected by rotating the casing or drill
stem at a point below the joint to be broken by
means of a rotary table while the section above
the joint is held stationary by suitable tongs, or by
holding stationary the casing or drill stem at a
point below the joint to be broken while the sec
tion above the joint is rotated by means of tongs.
In either procedure some means is provided to
take up the weight of the upper section during the
breaking of the joint, because unless this is done,
(Cl. 294-82)
casing hook in which the recoil referred to will be
eliminated.
It is a further object of this invention to provide
a casing hook which will serve to quickly remove
the section from the joint from which it is dis
connected, but which will retard any tendency
toward recoil and prevent the two parts of the
joint from being hammered together once they
have been separated by the spring of the casing
hook.
10
With the foregoing and other objects in view,
this invention contemplates the various parts and
combinations, and the various modifications
thereof illustrated in the accompanying drawings.
It is to be understood, however, that while 15
several modiñcations have been illustrated, the
same are by way of example only, and it is not to
be implied that all possible forms have been
shown. It is apparent that various other modi
fications may be made within the spirit and scope 20
of this invention, such spirit and scope being
limited only by the prior art and by the terms of
the appended claims.
Referring now more particularly to the draw
ings in which like numerals indicate correspond- 25
the weight of the section rests on the screw
ing parts throughout;
threads of the joint and tends to grind off and
damage the threads. To obviate this damage to
the screw threads, and for the purpose of saving
time, it is common to support the section being
Fig. 1 is a view partly in vertical cross section
illustrating one embodiment of this invention.
Fig. 2 is a horizontal section taken along the
line 2_2 of Fig. 1, and illustrating the adjusting 30
means employed in connection with the form
shown in Fig. 1.
Figs. 3 to 8, inclusive, are views similar to Fig. 1,
but illustrating various modiñed arrangements of
the respective parts.
35
Figs. 1a, 4a and 8a are enlarged fractional por
removed by a casing hook provided with a com
pression spring of such strength as to support the
section during the breaking out of the taper
threaded joint, and later after disengagement of
the threads to automatically lift said section high
enough to free it from all interference with its
former mating member.
Where such hooks are provided With merely a
spring for lifting the pipe section once it has been
disconnected, it has frequently been experienced
tions of Figs. 1, 4 and 8, respectively.
Fig. 9 is a View illustrating the application of a
casing hook constructed in accordance with this
invention.
5
that an operator is unable to push the section
Referring ñrst to the form shown in Fig. 1, the
removed aside exactly the moment it is pulled
upwardly by the spring, and that on the recoil the
hook l is supported by means of a yoke 2 or the
section removed will come back 'down and fre
quently hit against the joint from which it has
just been disconnected. This is obviously detri
mental tothe threads of the joint and causes con
siderable damage and delay when it occurs.
Furthermore, it is not an unknown occurrence for
a workman’s hand to slip between the sections
when the section is ñrst lifted, and to be greatly
injured when the sections come together again on
the recoil.
It is the purpose of this invention to provide a
40
like, such yoke having eyelets 3 at its lower ends
adapted to be received on the pintles 4 of the
block 5. The eyelets 3 are held on the pintles 4 45
by means of cap screws 6 or the like which secure
the washers 1 in place.
¿ The block 5 »is provided with a central bore
having a reduced portion at its upper end within
the externally threaded extension 8 of the block 5. 50
Threaded onto this extension 8 is a tubular mem
ber or cylinder 9 which extends upwardly from
the block. A passageway l0 constituting a by
pass is formed through the extension 8 in a longi
tudinal direction and communicates with the inte- 55
2,124,692
2
rior of the tubing 9 and with the interior of the
lower portion of the bore through the block 5.
The'size of this passageway I0 may be regulated
by suitable means such as a screw valve II.
A
second passageway I0', spaced from the passage
CII
way I0, also extends between the interior of the
tubing 9 and with the interior of the lower portion
of the bore through the block 5. This passageway
III’ is controlled by a ball valve I I ’ which permits
10 free movement therethrough in an upward direc
tion but prevents movement therethrough in a
downward direction.
The hook has a portion fitting within the lower
part of the boreA in the block 5 and provided with
a cup-shaped Washer I2 so as to form a fluid
seal between this portion of the hook and the
walls of the bore in the block. Thewalls I3 of
this bore are machined smooth so that the packing
or washer I2 may slide therein with the least
Above
the washer I2 the hook I carries a stem I4 of re
duced size, and the> upper end of this stem is
threaded at I5 to receive<` a nut I6 forming a
20 possible friction and form a good seal.
plunger which rides up-and down within the
cylinder 9. At a point adjacent its lower end
this plunger is provided with a cup-shaped wash
er I1 similar to the washer I2 on the lower por
tion of the hook with the exception that the
washer I1 is inverted. The upper end of the
30 nut I6 is provided with a head which extends lat
erally and limits the downward movement not
only of the nut I6, but of the hook I as well.
This nut I6 is locked in place by means of a lock
nut I9.
ì
Positioned below the lower end of the nut I6
and seated on the upper end of the extension 8
of the block 5 is a compression spring 20 which
is adapted to support the weight as hereinbefore
referred to.
A plug or other means may be pro
40 vided adjacent the upper end of the cylinder 9
for the purpose of atl least partially filling this
cylinder and the lower portion'of the bore through
the block 5 with a suitable liquid, which liquid
will act with a dashpot effect when the hook is
45 operated as will now be described.
The hook I is connected to a section of pipe
and an upward pull exerted until the spring 20
is compressed to the extent that the force exerted
by the spring will be suñicient to raise the sec
50
tion of pipe as soon as it is disconnected.
When
the section is disconnected, the force of the spring
will cause the pipe to be raised quickly, the fluid
passing freely upwardly through passageway I0',
until the joint at the lower end of the pipe is
free from the joint to which it has just been dis
connected. The dashpot eiïect of the fluid now
comes into play, the valve Il’ closing and the
fluid on its downward movement being forced
past the metering screw II. This prevents any
60 rapid downward movement of the hook, and con
55
sequently of the pipe section which has just been
removed.
This » dashpot arrangement thereby
takes up the recoil which would ordinarily be
taken up by the spring itself, and prevents the
downward recoil movement which has been re
65
ferred to above.
In the form illustrated in Fig. 3, the hook 2l is
supported by the yoke 22, the lower ends of which
are formed with eyelets 23 engaging the lugs
70 24 in a manner very similar to that illustrated in
Fig. 1.
The lugs 24 are carried on a block 25
which is for the most part hollow and open at
its upper end, but which is provided with an
upstanding cylindrical portion 26 centrally there
75 of. The cylindrical portion 26 when taken with
the outer walls of the block 25 provide an inner
cylindrical chamber 21 and an outer annular
chamber 28. Passing through the inner cham
ber is the stem 29 which is integral with the
upper end of the hook 2|, and surrounding this
stem 29 is the compression spring 30 correspond
ing to the spring 29 of Fig. 1. The stem 29 is
threaded at its upper e'nd as at 3| to receive an
inverted cup-shaped plunger member 32. This
member 32 has downwardly extending walls 33 10
carryingv at their lower ends an annular plunger
34 which is of such a size as to fit fairly snugly
within the annular chamber 28. This plunger
34 is .provided with a by-pass 35 extending from
its upper to its lower surface.
In addition to
the_by-pass 35 through the plunger 34, the block
25 is also provided with two or more by-passes.
One of these by-passes 36 is normally closed to
prevent movement of the fluid therethrough from
the space below the plunger to the space above 20
the same by means of a check valve 31.
The
check valve 31, however, is arranged to permit
free movement of the fluid from the space above
the plunger to the space below the same. The
other by-pass 38 is likewise provided with a check 25
valve 39, this check valve being spring pressed
by a spring 40 to retard movement of fluid from
below the plunger to the space above the same,
and to positively prevent movement of fluid from
the space above the plunger to the space below 30
the same.
,Y
The upper end of the block 25 is preferably
closed by a plate or dome 4I secured in place by
means of cap screws or the like 42.
In this form, the operation is similar to that 35
illustrated in Fig. 1 with the exception that upon
upward movement of the hook 2I the fluid is
permitted to pass freely through the by-pass 36
in the block 25 and thus permit the upward move
ment of the hook to be swift and sudden. On
the other hand, the downward movement is limit
ed both by the size of the opening 35 and by
the strength of the spring 40 so that the recoil
_which it is desired to eliminate will be effectively
damped.
With reference to the form illustrated in Fig.
4, this is very similar to that shown in Fig. 3.
In this form the hook 43 is supported by the yoke
44 having the eyelets 45 in engagement with the
lugs 46- on the block 41. An upstanding cylin
drical wall 48 is provided within this block 41, the
same being very similar to the wall 26 in Fig. 3.
Passing through the chamber 49 within this
cylindrical wall 48 is the stem 5I on the hook
43 and the spring 52 surrounds this stem in pre
cisely the same manner as shown in Fig. 3. Se
cured to the threaded upper end 53 of the stem
5I is the plunger member 54 which has down
wardly extending walls 55 carrying the annular
plunger 56. In this instance, the annular plung
er is so formed as to fit the annular chamber
50 loosely. 'I'he plunger is provided with a by
pass opening 51 therethrough similar to the open
ing 35 of Fig. 3. On the lower surface of this
annular plunger there is mounted a U-shaped
packing Washer 58 secured in place by means of
a ring 59 held to the plunger by cap screws 60
or the like. The upper end of the block 41 is
closed by a plate or dome 6I held to the block by
screws 62 in the manner readily apparent.
The operation of this hook is likewise similar
to that shown in Fig. 3, the exception being that
upon upward movement of the hook the ñuid is
allowed to pass from above the piston to the
space below the piston by virtue of the shape of
2,124,692
the cup-shaped packing 58, the by-passes 36 and
36 in the block being omitted.
In the form shown in Fig. 5 a somewhat diiïer
ent arrangement is provided. 'I'he hook 63 in
Ul this instance is supported by a yoke 64 having
eyelets 65 mounted on the lugs 66 of the block 61`.
. The block 61, however, is provided with two cy
lindrical chambers therein 68 and 69, these cham
bers being connected at their lower ends by a
10 passageway 10.
'I'here is also a passageway 1|
which connects the upper en'ds of these cylindrical
chambers, and which passes adjacent the lower
end of the cylindrical chambers and adjacent the
passageway 10. 'I'he passageways 10 and 1| are
interconnected by means of arestricted opening
12, and also by means of an opening 13 con
trolled by a ball Valve 14 normally urged into
seated position by a spring 15. The lower ends of
the chambers 60 and 69 are also connected to the
passageway 1|, these connections being controlled
by the ball valves 16 and 11, respectively, so posi
tioned as to permit passage of fluid from the pas
sageway 1| into the respective chambers, but to
prevent such passage in the opposite direction.
The balls 16 and 11 are retained adjacent the
openings they control by means of guards 10 and
19.
The upper ends of the chambers 00 and 99 are
closed by means of plugs 80 and 8|, respectively,
threaded into the upper ends of the chambers.
Each of these plugs is provided with an opening
through which the piston rods 32 and 83 are
adapted to move. These piston rods carry the
pistons 84 and 85, respectively, and are connected
at their upper ends by means of a cross head 90.
The cross head 86 is secured to the upper end of
the stem of the hook by means of a nut 0l' or the
like, the connection being loose so that the hook
‘may swivel with respect to the plungers. The
40 hook in this instance extends upwardly through
the block, and is provided with a compression
spring surrounding its stem in substantially the
same manner as illustrated in Fig. 7 of the draw
ings.
In operation, the device of Fig. 5 permits rapid
movement of the hook upwardly, the fluid within
the cylindrical chambers 60 and 69 passing in
such instance from the space above the pistons
through the passageway 1| and into the space
below the pistons through the valves 16 and 11.
0n downward movement, however, the hook is
forced to move slowly by the dashpot eifect
created by the necessity for the fluid in moving
from below the pistons to above the same to pass
QJI Li
through the restricted opening 12, and through
the passageway 13 controlled by the spring
pressed valve 14.
in Fig. 6, the hook 88 is supported by a yoke
89 having eyelets 90 engaging the plugs 9| on the
block 92 in substantially the same manner as
hereinbefore described. The block 92, however, is
in this instance formed with a single cylindrical
chamber 93 and with a passageway 94 connect
ing the upper end of this chamber with the lower
end thereof. Adjacent the lower end of the
chamber this passageway 94 communicates with
the interior of the chamber through a restricted
openingV 95, and at its lower end this passageway
is controlled by a valve 96 retained in place by a
guard 91. As will be seen,l this valve is such as
to permit free passage of fluid into the lower end
of the chamber, but to prevent passage from the
lower end of the chamber except through the
restricted opening 95.
The upper end of the cylindrical chamber 93
3
is closed by a threaded plug 98 having an opening
therethrough receiving the slidable piston rod 99.
On its lower end this- piston rod carries the piston
|00 which is reciprocable in the cylindrical cham
ber and secured at its upper end is the cross head
|0|. 'I'his cross head |0| is secured to the stem
of the hook 88 by a nut |02 or the like, these
connections and the spring which surrounds the
stem of the hook within the block 92 «being sub
stantially the same as that illustrated in Fig. '1
now to be described.
’It will be appreciated that in this form the
hook 88 is permitted to move upwardly without
restriction, the ñuid which is employed within the
cylinder 93 passing in such instance from the 15
upper portion of the cylinder to the lower por
tion of the cylinder through the valve 96. On its
downward movement, however, it is restricted to
passage through the small opening 95 and the re
coil is thus substantially eliminated.
20
In Fig. '7, the arrangement is substantially the
same as in Fig. 6, the hook |03 being supported
by a yoke |00 which is in turn secured to the block
|05 in substantially the same manner. The block
|05 is similar provided with a single cylindrical 25
chamber |00 and with a passageway |01 connect
ing the upper portion thereof with the lower por
tion thereof. rl'he lower end of this passageway
communicates with the interior of the chamber
|06 through two openings, one of which is con 30
trolled by a spring pressed valve |00 held in
place by a spring |09, and the other oi which is
controlled by a ‘call valve ||0 retained by a
guard iii. The upper end of the chamber is
closed by a plug ||2 formed to accommodate the
piston rod ilêi carrying a piston lill at its lower
end. At its upper end a cross head H5 is pro
vided. By means of a’ castle nut- H0, the cross
head iliiis secured to a fitting M0 in such a
manner as to permit the fitting to swivel with
respect to the cross head. This íitting is in turn
threaded at liti to the upper end of the stem
|20 on the hook |03. Surrounding the stem |20
between the lower portion of the block |05 and
the fitting H0 is a compression spring |2i, this
spring having the same function as the springs
illustrated in Figs. i, 3 and á.
In this form of hook, upward movement of the
hook is permitted freely by virtue of the fact
that the fluid which is used within the cylindri
cal chamber |06 may pass from above the piston
through the passageway |01 and upwardly into
the space below the piston through the valve
| I0. On downward movement, however, the fluid
must pass by the spring pressed valve |00, the
strength of the spring |09 being such as to damp
the movement of the piston by restricting the
movement of the fluid from below the piston.
In the illustration of Fig. S, the hook |22 is
40
45
5@
65
supported by the yoke |23 having eyelets |24 on
its lower ends engaging the plugs |25 on the
block |26. The block |26 has a cylindrical cham
ber therein at |21, but is not provided with any
passageways corresponding to those described in
the preceding paragraphs. The upper end of the 65
chamber |21 is closed by a plug |28 which is
formed to provide for the passage of the piston
rod |29. The piston |30 is carried on the lower
end of this rod and fits loosely within the cham 70
ber |21. A cup-shaped packing |3| is secured
to the lower face of the piston' |30 by means of
a plate |32 and cap screws or the like |33. Ex
tending through the piston |30, the packing |3|,
and the plate |32, is a passageway |34 of such 75
4
2,124,692
size as to restrict the passage of fluid there
through.
The upper end of the piston rod |29 is se-‘
tion between the hook |22 and the nut |36 is
tion of hooks disclosed in this application and
that the term "yoke" is likewise to be taken as
yoke elements disclosed in the drawing of this
application but performing substantially the same
function, namely, the function of a pendant
support.
In view of the foregoing, it will be seen that a
means has been provided for carrying out all
|3| and is compelled to pass through the re
the objects and advantages sought by this in
vention.
tration.
It will be seen that the hook 2| in this
by a suitably supported block |44 in a manner
which is well known to those skilled in the art.
When it is desired to disconnect a section such
as |39, the section is pulled to a point above the
support |44 and the slips |43 are then engaged
35 to support the lower portion of the string of
pipe.
A sufficient force is exerted on the hook
2l to compress the spring 30 included therein,
and to move the annular piston 34 to its lower
most position. The tool joint sections |40 and
40
|4| are thereupon unscrewed to disjoint the sec
tion |39. Immediately upon disengagement of
the threads of the respective parts of the tool
joint the spring 30 will expand andcause the
annular piston 34 to be raised to its uppermost
45
position within the annular chamber 28. In such
.movement fluid is permitted to pass from above
the piston through the passageway 36 and pass
the Valve 31, no restriction being imposed upon
this passage of fluid. This leaves the section |39
50 in the position illustrated in Fig. 9. Naturally,
there is a. tendency for a recoil to take place, and
for this section to again move downwardly tend
ing to bring the threaded ends of the tool joint
into engagement the second time. This is pre
vented, however, in this instance by virtue of the
fact that the iluid is trapped in the annular
space below the piston 34, and before this piston
can move downwardly, and hence before the
hook 2| and the section |39 can move down
wardly, the fluid must either pass through the
small opening 35 in the piston, or must be forced
past the spring pressed valve 39, and through
the passageway 30. Since it requires consider
able time for the fluid to pass from one space
to the other by either of these routes, the ten
dency to recoil is effectively overcome.
In the foregoing description and in the fol
lowing claims this invention has been referred
70 to as a casing hook. It will be understood, how
ever, that this term is not intended as in any
way a limitation, but that it is intended that this
invention shall include all hooks of the nature
claimed which are capable of being employed
75 either during the removal of a casing from a
Cn
including elements shaped differently from the
stricted passageway |34 in moving from below
the piston to the space above the same. Any
instance is engaged with a yoke |31 secured to
25 a clamp |38 by which the section of tubing |39
is being held. On the lower end of this section
of tubing is the pin portion of a tool joint |40,
the box portion |4| being on the upper end of
the string of pipe |42. This string is in this in
30 stance supported by means of slips |43 carried
65
.
It will also be understood that the term ‘_‘hook”
is to be taken as including elements not’neces
sarily shaped as hooks but performing the func
recoil is thereby taken up.
The application of the various casing hooks
20
above described is illustrated in Fig. 9, the hook
of Fig. 3 being shown here for purposes of illus
60
a well or other opening.
cured to a cross head |35 which is in turn se
cured to the upper end of the stem or hook |22
by means of a nut |36 or the like. The connec
similar in all respects to the corresponding struc
ture shown in Fig. 7.
In this form, the upward movement of the
10
hook |22 is unrestricted because of the fact that
the fluid which is used in the chamber |21 may
pass unrestrictedly by the piston |30 and the
cup-shaped packing |3|. On downward move
ment, however, the fluid is held by the packing
i
well, or during the removal of a drill stem, or
during the removal of any other pipe or rod from
Having described our invention, we claim:
l. In a casing hook, in combination, a yoke
member, a spring supported thereby, a hook
member supported on said spring, a dashpot hav
ing relatively movable parts connected to said
yoke and to said hook, respectively, said dashpot
including means for retarding without substan
tially restricting downward movement of said 25
hook while permitting substantially free upward
movement thereof with respect to said yoke.
2. In a casing hook, a yoke, a member carried
by said yoke and having a fluid chamber therein, v
a spring carried by said member, a hook support
ed on said spring, a piston in said chamber and
connected with said hook for movement in said
chamber on upward or downward movement of
said hook, and means for retarding a flow of
fluid past said piston on downward movement
of said hook and for conducting such ñuid free
ly past said piston on upward movement of said
hook, whereby said hook will be retarded on
downward movement, and free from retardation
on upward movement.
40
3. In a casing hook, a yoke, a member carried
by said yoke and having a liquid chamber there
in, a spring carried by said member, a hook sup
ported on said spring, a plunger movable in said
chamber and connected with said hook for move
ment in said chamber on downward movement
of said hook, a liquid in said chamber, and means
retarding the escape of said liquid from its posi
tion in said chamber ahead of said plunger on
downward movement of said hook.
4. In a casing hook, a yoke, a member carried
by said yoke and having a fluid chamber and a
spring chamber therein, a spring in said spring
chamber, a hook supported on said spring, a
plunger in said fluid chamber and connected with
said hook for movement in said chamber on
downward movement of said hook, a fluid in said
chamber, and means retarding the escape of said
fluid from its position in said chamber ahead
of said plunger upon downward movement of said
hook.
5. In a casing hook, a yoke, a member carried
by said yoke and having a fluid chamber and a
spring chamber therein, a spring in said spring
chamber, a hook supported on said spring, a
plunger in said fluid chamber and connected
with said hook for movement in said chamber
on downward movement of said hook, a swivel
connection between said hook and said plunger,
a fluid in said chamber, and means retarding the
escape of said fluid from its position in said
chamber ahead of said plunger upon downward
movement of said hook.
6. In a casing hook, a yoke, a. member carried
by si id yoke and having a fluid liamber and a
2,124,692
spring chamber therein, said fluid and spring
chambers being spaced laterally from each other,
5
chamber and connected to said hook for move
ment in said chamber on downward movement
a spring in said spring chamber, a hook support
of said hook, a fluid in said chamber, said cham
ed on said spring, a plunger in said fluid cham
ber having a restricted opening therein for per
ber and connected with said hook for movement ' mltting retarded escape of said fluid from its
in said chamber on downward movement of said position in said chamber ahead of said plunger
hook, a fluid in said chamber, and means re
upon downward movement of said hook, and a
tarding the escape of said fluid from its position
in said chamber ahead of said plunger upon
10 downward motion of said hook.
7. In a casing hook, a yoke, a member carried
by said yoke and having a fluid chamber and a
spring chamber therein, said fluid and spring
chambers being substantially concentric with re
spect to each other, a spring in said spring cham
ber, a hook supported on said spring, a plunger
in said fluid chamber and connected with said
hook for movement in said chamber on down
ward movement of said hook, a fluid in said
20 chamber, and means retarding the escape of said
fluid from its position in said chamber ahead of
said plunger upon downward motion of said hook.
8. In a casing hook, a yoke, a member carried
by said yoke, and having a fluid chamber and a
25 spring chamber therein, a spring in said spring
chamber, a hook supported on said spring, a
piston in said fluid chamber and connected with
said hook for movement in said chamber on
downward movement of said hook, a fluid in said
30 chamber, means retarding the escape of said
fluid from its position ln Ysaid chamber ahead of
said plunger upon downward motion o_f said
hook, and for freely conducting ñuid into said
chamber upon upward motion of said hook.
35
9. In a casing hook, a yoke, a member carried
by said yoke and having a fluid chamberand a
spring chamber therein, said fluid and spring
chambers being substantially concentric and said
fluid chamber being of annular form, a spring in
40 said spring chamber, a hook supported on said
spring, an annular plunger in said annular fluid
chamber and connected with said hook for move
ment in said chamber on downward movement
of said hook, a fluid in said chamber, and means
45 retarding the escape of said fluid from its posi
tion in said chamber ahead of said piston upon
downward motion of said hook.
10. In a casing hook, a yoke, a member car
ried by said yoke and having a liquid chamber
50 therein, a spring carried by said member, a hook
supported on said spring, a plunger movable in
said chamber and connected with said hook for
movement in said chamber on downward move
ment of said hook, a liquid in said chamber, and
55 means retarding the escape of said liquid from
its position in said/chamber ahead of said plunger
upon downward motion of said hook and for
freely admitting fluid to said chamber upon up
ward motion of ~said hook.
60
11. In a casing hook, a yoke, a member carried
by said yoke and havinga liquid chamber therein,
a spring within said liquid chamber, a hook sup
ported on said spring, a plunger movable in said
chamber and connected with said hook for move
ment in said chamber on downward movement
of said hook, a liquid in said chamber, and means
retarding the escape of said liquid from its posi
tion ln said chamber ahead of said plunger upon
downward motion of said hook.
70
12. In a casing hook, a yoke, a member carried
by said yoke and having a fluid chamber and a
spring chamber therein, said fluid and spring
chambers being spaced laterally from each other,
a spring in said spring chamber, a hook sup
ported on said spring, a plunger in said fluid
freely operating check valve for freely admitting
fluid to said chamber upon upward movement of
said hook.
10
13. In a casing hook, a yoke, a member carried
by said yoke and having a fluid chamber and a
spring chamber therein, said fluid and spring
chambers being spaced laterally from each other,
a spring in said spring chamber, a hook supported 15
on said spring, a plunger in said fluid chamber
and connected with said hook for movement in
said chamber on downward movement of said
hook, a fluid in said chamber, said chamber hav
ing a restricted opening therein for permitting 20
unrestricted escape of said fluid from its position
in said chamber ahead of said plunger upon
downward movement of said hook, a spring
pressed check valve arranged to permit addi
tional escape of said fluid upon placing of an
excessive load on said hook, and a freely operat
ing check valve for >freely admitting fluid into
said chamber upon upward movement of said
hook.
14. In a casing hook, a yoke, a member carried 30
by said yoke and having a fluid chamber and a
spring chamber therein, said fluid and spring
chambersbeing spaced laterally from each other,
a spring in said spring chamber, a hook supported
on said spring, a plunger in said fluid chamber
and connected with ksaid hook for movement in
said chamber on downward movement of said
hook, a fluid in said chamber, a flexible cup
shaped washer on said plunger for preventing
movement of said fluid between the walls of said
chamber and the sides of said plunger upon down
ward movement of said hook, but permitting rela
tively free movement of said fluid in the opposite
direction upon upward movement of said hook,
and said plunger having a restricted passageway 45
therethrough for permitting retarded escape of
said fluid from its position in said chamber ahead
of said plunger upon downward motion of said
hook.
15. In a casing hook, a yoke, a member carried 50
by said yoke and having a fluid chamber and a
spring chamber therein, said fluid and spring
chambers being substantially concentric with re
spect to each other, a spring in said spring cham
ber, a hook supported on said spring, a plunger in 55
said fluid chamber and connected with said hook
for movement in said chamber on downward
movement of said hook, a fluid in said chamber,
said chamber having a restricted opening therein
for permitting retarded escape of said fluid from 80
its position in said chamber ahead of said plunger
upon downward movement of said hook, a spring
pressed check valve arranged to permit additional
retarded escape of said fluid upon the placing of
an excessive load on said hook, and a freely mov
65
able check valve arranged to freely admit fluid
to said chamber upon upward movement of said
hook.
16. In a casing hook, a yoke, a member carried
by said yoke and having a fluid chamber and a 70
spring chamber therein, said fluid and spring
chambers being substantially concentric with re
spect to each other, a spring in said spring cham
ber, a hook supported on said spring, a plunger
in said fluid chamber and connected with said 75
2,124,692
6
hook for movement in said chamber on down
ward movement-of said hook, said structure hav-.
ing a restricted opening therein for permitting
retarded escape of said iluid from its position in
said chamber ahead of said plunger upon down
ward movement of said hook, and a U-shaped
washer on said plunger adapted to slidingly con
tact the walls of said chamber and prevent move
ment of said fluid past said plunger upon down
10 ward movement of said hook while permitting
substantially free movement of said ñuid past
said plunger upon upward movement of said
hook.
-
17. In a casing hook, a yoke, a member carried
Í15 by said yoke and having a spring chamber and
a plurality of fluid chambers therein, said fluid
chambers occupying balanced positions on oppo-V
site sides of said spring chamber, a spring in said
spring chamber, a hook supported on said spring,
20 plungers in said fluid chambers respectively, and
each connected with said hook for movement in
said chambers on downward movement of said
hook, a fluid in said chambers, and means retard
ing the escape of said fluid from its position in
said chambers ahead of said plungers upon down
ward movement of said hook.
18. In a, casing hook, a yoke, a member carried -
by said yoke and having a spring chamber and a
plurality of ñuid chambers therein, said liiuid
chambers occuping balanced positions on oppo
site sides of said spring chamber, a spring in said>
spring chamber, a hook supported on said spring,
plungers in said fluid chambers, respectively, and
each connected with said hook for movement in 10
said chambers on downward movement of said
hook, a fluid in said chambers, a restricted open
ing in said chamber for permitting retarded es
cape of said fluid from its position in said cham
ber ahead of said plunger upon downward move 15
ment of said hook, a spring-pressed check valve
arranged to permit additional retarded escape of
said fluid from said chamber upon the placing of
an excessive load on said hook, and a freely mov
able check valve arranged to freely admit iluid 20
into said chamber upon upward movement of said
hook.
GEORGE F. FERMIER.
JOHN _C. STOKES.
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