Fishing jar for accommodation of excess tensile load

Claim 2

In a hydraulic fishing jar adapted to be run into a well on a fishing string and connected to a fishing tool in the well bore: (a) inner and outer telescopically interengaged bodies; (b) means defining between said bodies a hydraulic fluid chamber having at least three associatable fluid chamber members; (c) means in the chamber operable upon tensioning the fishing string for telescopic movement of said bodies to compress and apply a predetermined force to a plurality of said fluid chamber members; (d) there being by-pass flow passage means in one of said bodies; (e) valve means in the chamber for normally closing off one end of the by-pass flow passage means from the compressed fluid in the chamber and responsively activatable to open so that compressed hydraulic fluid is released to the by-pass flow passage means; (f) flow by-pass means to transfer the compressed hydraulic fluid in the chamber and thereby move said fluid in said chamber to engage and move said valve means to open the by-pass flow passage means at one end to the compressed hydraulic fluid upon application of said predetermined force; (g) pressure relief means activatable at forces substantially in excess of said predetermined force to meter fluid therethrough and to transfer fluid pressure resulting from said excess force and within one of said plurality of hydraulic fluid chamber members to another of said plurality of hydraulic fluid chamber members whereby said valve is engaged and moved to open the by-pass flow passage means at one end of the compressed hydraulic fluid chamber; and (h) hammer and anvil means on said bodies movable into engagement when said valve member and valve means open the by-pass passage means to the chamber across said flow by-pass means.

Claim 3

The invention of claim 1 wherein said flow by-pass means includes piston means, said piston means having seal means sealably and slidably engaged in the chamber to provide cross sectional areas of different size on said piston means responsive to the compressed hydraulic fluid in the chamber for transfer thereof across said piston means.

Claim 4

The invention of claim 2 wherein said cross sectional areas are of a predetermined relationship for controlling the compressed hydraulic fluid pressure differential across said piston means in the chamber acting to move said piston means.

Claim 5

The invention of claim 2 wherein said piston means is an annular member having top and bottom ends and wherein the cross sectional area defined by said seal means adjacent said bottom piston end is smaller than the cross sectional area defined by said seal means adjacent said top piston means.

Claim 6

The invention of claim 2 including resilient means in the chamber urging said piston means away from said valve means and yieldable as said piston means moves to engage said valve means.

Claim 7

The invention of claim 5 wherein said resilient means urging said piston means away from said valve means also engages said means in the chamber operable upon tensioning the fishing string and is yieldable upon movement of said piston means relative to said means in the chamber operable upon tensioning the fishing string.

Claim 8

The invention of claim 1 wherein said means defining the hydraulic fluid chamber comprises upper and lower seal means between said bodies, one of said seal means being a floating piston for compensating for the pressure of fluid in the well.

Claim 9

The invention of claim 1 wherein said valve means is slidably and sealably carried by said inner body.

Claim 10

The invention of claim 1 wherein said valve means is slidably and sealably carried by said outer body.

Claim 11

The invention of claim 1 wherein said by-pass flow passage means is formed in said outer body.

Claim 12

The invention of claim 1 wherein said by-pass flow passage means is formed in said inner body.

Claim 13

The invention of claim 2 wherein said piston means is slidably and sealably carried in said chamber.

Claim 14

The invention of claim 2 wherein one of said cross sectional areas is defined by seal means between said piston means and inner body and seal means between said piston means and outer body, and the other of said cross sectional areas is defined by seal means between said piston means and outer body and seal means between said piston means and inner body.

Claim 15

The invention of claim 2 wherein said cross sectional areas are of a predetermined relationship for maintaining the compressed hydraulic fluid pressure differential across said piston means within a predetermined range.

Claim 16

The invention of claim 1 wherein said flow by-pass means includes flow regulator means whereby compressed hydraulic fluid is movable therethrough within the predetermined pressure differential.

Claim 17

The invention of claim 15 wherein said flow regulator means is flow reversible.

Claim 18

The invention of claim 2 further comprising a flow reversible element for transmission of fluid in the chamber above said piston means to the chamber below the piston means.

Claim 19

The invention of claim 17 wherein said flow reversible element comprises a check valve.

Claim 20

The invention of claim 1 further comprising a flow reversible element for transmission of fluid in the chamber below the valve means to the chamber above the valve means.

Claim 21

In a hydraulic fishing jar adapted to be run into a well on a fishing string and connected to a fishing tool in the well bore: (a) inner and outer telescopic bodies; (b) means including longitudinally spaced seals defining between said bodies a hydraulic fluid chamber; (c) power piston means including an annular piston carried by one of said bodies and shiftable longitudinally in said chamber by the other of said bodies upon tensioning the fishing string for telescopic movement of said bodies to compress and apply a predetermined force to the hydraulic fluid in the chamber; (d) therebeing by-pass flow passage means in one of said bodies; (e) a valve member in the chamber for normally closing off one end of the by-pass flow passage means from the compressed fluid in the chamber and shiftable to open so that compressed hydraulic fluid is released to the by-pass flow passage means; (f) piston means including flow by-pass means to transfer the compressed hydraulic fluid in the chamber across said piston means and thereby move it in the fluid chamber to engage and move said valve member to open the by-pass flow passage means at one end to the compressed hydraulic fluid; (g) said piston means including valve means normally closing off the other end of by-pass flow passage means and shiftable to open so that hydraulic fluid is released from the chamber above said piston means; (h) means on said inner body to move said piston valve means and open the other end of the by-pass flow passage means when said valve member is moved to open one end of the by-pass flow passage means to the compressed hydraulic fluid; (i) hammer and anvil means on said bodies movable into engagement when said valve member and piston valve means open the by-pass passage means to the chamber across said piston means; and (j) pressure relief means associated with said piston means and activatable at forces substantially in excess of said predetermined force to meter fluid therethrough and to transfer fluid pressure resulting from said excess force and within said chamber whereby said valve is engaged and moved to open the by-pass flow passage means to one of the compressed hydraulic fluid chambers.

Claim 22

In a hydraulic fishing jar adapted to be run into a well on a fishing string and connected to a fishing tool in the well bore: (a) inner and outer telescopic bodies; (b) means including longitudinally spaced seals defining between said bodies a hydraulic fluid chamber; (c) power piston means including an annular piston carried by one of said bodies and shiftable longitudinally in said chamber by the other of said bodies upon tensioning the fishing string for telescopic movement of said bodies to compress and apply a predetermined force to the hydraulic fluid in the chamber; (d) therebeing by-pass flow passage means in one of said bodies; (e) a valve member in the chamber for normally closing off one end of the by-pass flow passage means from the compressed fluid in the chamber and shiftable to open so that compressed hydraulic fluid is released to the by-pass flow passage means; (f) piston means including flow by-pass means to transfer the compressed hydraulic fluid in the chamber across said piston means and thereby move it in the fluid chamber to engage and move said valve member to open the by-pass flow passage means at one end to the compressed hydraulic fluid; (g) said piston means including valve means normally closing off the other end of by-pass flow passage means and shiftable to open so that hydraulic fluid is released from the chamber above said piston means; (h) means on said inner body to move said piston valve means and open the other end of the by-pass flow passage means when said valve member is moved to open one end of the by-pass flow passage means to the compressed hydraulic fluid; (i) hammer and anvil means on said bodies movable into engagement when said valve member and piston valve means open the by-pass passage means to the chamber across said piston means; and (j) pressure relief means associated with said piston means and activatable at forces substantially in excess of said predetermined force to meter fluid therethrough and to transfer fluid pressure resulting from said excess force and within said chamber whereby said valve is engaged and moved to open the by-pass flow passage means to one of the compressed hydraulic fluid chambers.

Claim 23

The invention of claim 20 wherein said piston means includes seal means sealably and slidably engaged in the chamber to provide cross sectional areas of different size on said piston means responsive to the compressed hydraulic fluid in the chamber for transfer thereof across said piston means.

Claim 24

The invention of claim 21 wherein said cross sectional areas are of a predetermined relationship for controlling the compressed hydraulic fluid pressure differential across said piston means in the chamber acting to move said piston means.

Claim 25

The invention of claim 22 wherein said piston means is an annular member having top and bottom ends and wherein the cross sectional area defined by said seal means adjacent said bottom piston end is smaller in size than the cross sectional area defined by said seal means adjacent said top piston end.

Claim 26

The invention of claim 20 including annular seat means formed on said piston valve means and said piston means for seating said piston valve means on said piston means.

Claim 27

The invention of claim 20 including resilient means normally urging said piston valve means into sealing engagement with said piston means until said means on said inner body engages said valve means.

Claim 28

The invention of claim 20 wherein said means on said inner body at one end thereof forms seat means for said valve member.

Claim 29

The invention of claim 26 including resilient means normally urging said valve member into sealing engagement with said seat means until said piston means moves said valve member off said seat means.

Claim 30

The invention of claim 20 including resilient means in the chamber urging said piston means away from said valve member and yieldable as said piston means moves to engage said valve member.

Claim 31

The invention of claim 21 wherein said valve member is slidably and sealably carried by said inner body.

Claim 32

The invention of claim 28 wherein said resilient means urging said piston means away from said valve member also engages said power piston and is yieldable upon movement of said piston means relative to said power piston.

Claim 33

The invention of claim 20 wherein said piston valve means is slidably and sealably carried by said inner body.

Claim 34

The invention of claim 20 wherein said piston means is slidably and sealably carried in said chamber.

Claim 35

The invention of claim 20 wherein the by-pass flow passage means is formed in said inner body.

Claim 36

The invention of claim 21 wherein one of said cross sectional areas is defined by seal means between said piston valve means and inner body and seal means between said piston means and outer body, and the other of said cross sectional areas is defined by seal means between said piston means and outer body and seal means between said piston means and inner body.

Claim 37

The invention of claim 21 wherein said cross sectional areas are of a predetermined relationship for maintaining the compressed hydraulic fluid pressure differential across said piston means within a predetermined range.

Claim 38

The invention of claim 20 wherein said flow by-pass means includes flow regulator means whereby the compressed hydraulic fluid moves therethrough at a constant rate within the predetermined pressure differential.

Claim 39

In a well bore fishing string hydraulic fishing jar having inner and outer telescopically interengaged bodies with a hydraulic fluid chamber therebetween having at least three associatable fluid chamber members and power piston means in the chamber to compress and apply a predetermined force to the hydraulic fluid in the chamber upon tensioning the fishing string for telescopic movement of the bodies to a plurality of said fluid chamber members, the improvement comprising: (a) by-pass flow passage means in one of the bodies; (b) a fluid metering member in the chamber in association with one end of the by-pass flow passage means from the compressed fluid in the chamber and operational so that compressed hydraulic fluid is selectively released to the by-pass flow passage means; (c) piston means including pressure relief means to transfer the compressed hydraulic fluid within one of said plurality of hydraulic fluid chamber members to another of said plurality of hydraulic fluid chamber members across said piston means and thereby move it in the fluid chamber at forces in excess of a predetermined force applicable to said jar, to open the by-pass flow passage means at one end to the compressed hydraulic fluid; (d) said piston means including valve means in the chamber normally closing off the other end of the by-pass flow passage means and shiftable to open so that hydraulic fluid is released from the chamber above said piston means; and (e) hammer and anvil means on said bodies movable into engagement when said fluid metering member and piston valve means open the by-pass passage means to the chamber across said piston means.

Claim 40

In a well bore fishing string hydraulic fishing jar having inner and outer telescopically interengaged bodies with a hydraulic fluid chamber therebetween having at least three associatable fluid chamber members and power piston means in the chamber to compress and apply a predetermined force to the hydraulic fluid in the chamber upon tensioning the fishing string for telescopic movement of the bodies to a plurality of said fluid chamber members, the improvement comprising: (a) by-pass flow passage means in one of the bodies; (b) a fluid metering member in the chamber in association with one end of the by-pass flow passage means from the compressed fluid in the chamber and operational so that compressed hydraulic fluid is selectively released to the by-pass flow passage means; (c) piston means including pressure relief means to transfer the compressed hydraulic fluid within one of said plurality of hydraulic fluid chamber members to another of said plurality of hydraulic fluid chamber members across said piston means and thereby move it in the fluid chamber at forces in excess of a predetermined force applicable to said jar, to open the by-pass flow passage means at one end to the compressed hydraulic fluid; (d) said piston means including valve means in the chamber normally closing off the other end of the by-pass flow passage means and shiftable to open so that hydraulic fluid is released from the chamber above said piston means; and (e) hammer and anvil means on said bodies movable into engagement when said fluid metering member and piston valve means open the by-pass passage means to the chamber across said piston means.

Claim 41

The invention of claim 37 wherein said piston means includes seal means sealably and slidably engaged in the chamber to provide cross sectional areas of different size on said piston means responsive to the compressed hydraulic fluid in the chamber for transfer thereof across said piston means.

Claim 42

The invention of claim 38 wherein one of said cross sectional areas is defined by seal means between said piston means and inner body and seal means between said piston means and outer body, and the other of said cross sectional areas is defined by seal means between said piston means and outer body and seal means between said piston means and inner body.

Claim 43

The invention of claim 38 wherein said cross sectional areas are of a predetermined relationship for maintaining the compressed hydraulic fluid pressure differential across said piston means within a predetermined range.

Claim 44

The invention of claim 37 wherein said flow by-pass means includes substantially constant flow regulator means whereby the compressed hydraulic fluid moves therethrough at a rate within the predetermined pressure differential.

Claim 45

In a hydraulic fishing jar adapted to be run into a well on a fishing string and connected to a fishing tool in the well bore; (a) inner and outer telescopically interengaged bodies; (b) means defining between said bodies a hydraulic fluid chamber having three associatable fluid chamber members; (c) means in the chamber operable upon tensioning the fishing string for telescopic movement of said bodies to compress and apply a predetermined force to two of said fluid chamber members; (d) there being by-pass flow passage means in one of said bodies; (e) valve means in the chamber for normally closing off one end of the by-pass flow passage means from the compressed fluid in the chamber and responsively activatable to open so that compressed hydraulic fluid is released to the by-pass flow passage means; (f) flow by-pass means to transfer the compressed hydraulic fluid in the chamber and thereby move said fluid in said chamber to engage and move said valve means to open the by-pass flow passage means at one end to the compressed hydraulic fluid upon application of said predetermined force; (g) pressure relief means activatable at forces substantially in excess of said predetermined force to meter fluid therethrough and to transfer fluid pressure resulting from said excess force and within one of said two hydraulic fluid chamber members to the other of said two hydraulic chamber members whereby said valve is engaged and moved to open the by-pass flow passage means at one end of the compressed hydraulic fluid chamber; and (h) hammer and anvil means on said bodies movable into engagement when said valve member and valve means open the by-pass passage means to the chamber across said flow by-pass means.

Claim 46

In a hydraulic fishing jar adapted to be run into a well on a fishing string and connected to a fishing tool in the well bore; (a) inner and outer telescopically interengaged bodies; (b) means defining between said bodies a hydraulic fluid chamber having three associatable fluid chamber members; (c) means in the chamber operable upon tensioning the fishing string for telescopic movement of said bodies to compress and apply a predetermined force to two of said fluid chamber members; (d) there being by-pass flow passage means in one of said bodies; (e) valve means in the chamber for normally closing off one end of the by-pass flow passage means from the compressed fluid in the chamber and responsively activatable to open so that compressed hydraulic fluid is released to the by-pass flow passage means; (f) flow by-pass means to transfer the compressed hydraulic fluid in the chamber and thereby move said fluid in said chamber to engage and move said valve means to open the by-pass flow passage means at one end to the compressed hydraulic fluid upon application of said predetermined force; (g) pressure relief means activatable at forces substantially in excess of said predetermined force to meter fluid therethrough and to transfer fluid pressure resulting from said excess force and within one of said two hydraulic fluid chamber members to the other of said two hydraulic chamber members whereby said valve is engaged and moved to open the by-pass flow passage means at one end of the compressed hydraulic fluid chamber; and (h) hammer and anvil means on said bodies movable into engagement when said valve member and valve means open the by-pass passage means to the chamber across said flow by-pass means.

Claim 47

The invention of claim 42 wherein said flow by-pass means includes piston means, said piston means having seal means sealably and slidably engaged in the chamber to provide cross sectional areas of different size on said piston means responsive to the compressed hydraulic fluid in the chamber for transfer thereof across said piston means.

Claim 48

The invention of claim 43 wherein said cross sectional areas are of a predetermined relationship for controlling the compressed hydraulic fluid pressure differential across said piston means in the chamber acting to move said piston means.

Claim 49

The invention of claim 43 wherein said piston means is an annular member having top and bottom ends and wherein the cross sectional area defined by said seal means adjacent said bottom piston end is smaller than the cross sectional area defined by said seal means adjacent said top piston end.

Claim 50

The invention of claim 43 including resilient means in the chamber urging said piston means away from said valve means and yieldable as said piston means moves to engage said valve means.

Claim 51

The invention of claim 46 wherein said resilient means urging said piston means away from said valve means also engages said means in the chamber operable upon tensioning the fishing string and is yieldable upon movement of said piston means relative to said means in chamber operable upon tensioning the fishing string.

Claim 52

The invention of claim 42 wherein said means defining the hydraulic fluid chamber comprises upper and lower seal means between said bodies, one of said seal means being a floating piston for compensating for the pressure of fluid in the well.

Claim 53

The invention of claim 42 wherein said valve means is slidably and sealably carried by said inner body.

Claim 54

The invention of claim 42 wherein said valve means is slidably and sealably carried by said outer body.

Claim 55

The invention of claim 42 wherein said by-pass flow passage means is formed in said outer body.

Claim 56

The invention of claim 42 wherein said by-pass flow passage means is formed in said inner body.

Claim 57

The invention of claim 43 wherein said piston means is slidably and sealably carried in said chamber.

Claim 58

The invention of claim 43 wherein one of said cross sectional areas is defined by seal means between said piston means and inner body and seal means between said piston means and outer body, and the other of said cross sectional areas is defined by seal means between said piston means and outer body and seal means between said piston means and inner body.

Claim 59

The invention of claim 43 wherein said cross sectional areas are of a predetermined relationship for maintaining the compressed hydraulic fluid pressure differential across said piston means within a predetermined range.

Claim 60

The invention of claim 42 wherein said flow by-pass means includes flow regulator means whereby compressed hydraulic fluid is movable therethrough within the predetermined pressure differential.

Claim 61

The invention of claim 42 wherein said flow regulator means is flow reversible.

Claim 62

The invention of claim 43 further comprising a flow reversible element for transmission of fluid in the chamber above said piston means to the chamber below the piston means.

Claim 63

The invention of claim 58 wherein said flow reversible element comprises a check valve.

Claim 64

The invention of claim 42 further comprising a flow reversible element for transmission of fluid in the chamber below the valve means to the chamber above the valve means.

Claim 65

In a well bore fishing string hydraulic fishing jar having inner and outer telescopically interengaged bodies with the hydraulic fluid chamber therebetween having three associatable fluid chamber members and power piston means in the chamber to compress and apply a predetermined force to the hydraulic fluid in the chamber upon tensioning the fishing string for telescopic movement of the bodies to two of said fluid chamber members, the improvement comprising: (a) by-pass flow passage means in one of the bodies; (b) a fluid metering member in the chamber in association with one end of the by-pass flow passage means from the compressed fluid in the chamber and operational so that compressed hydraulic fluid is selectively released to the by-pass flow passage means; (c) piston means including relief means to transfer the compressed hydraulic fluid within one of said two hydraulic fluid chamber members to the other of said two hydraulic fluid chamber members across said piston means and thereby move it in the fluid chamber at forces in excess of a predetermined force applicable to said jar, to open the by-pass flow passage means at one end to the compressed hydraulic fluid; (d) said piston means including valve means in the chamber normally closing off the other end of the by-pass flow passage means and shiftable to open so that hydraulic fluid is released from the chamber above said piston means; and (e) hammer and anvil means on said bodies movable into engagement when said fluid metering member and piston valve means open the by-pass passage means in the chamber across said piston means.

Claim 66

In a well bore fishing string hydraulic fishing jar having inner and outer telescopically interengaged bodies with the hydraulic fluid chamber therebetween having three associatable fluid chamber members and power piston means in the chamber to compress and apply a predetermined force to the hydraulic fluid in the chamber upon tensioning the fishing string for telescopic movement of the bodies to two of said fluid chamber members, the improvement comprising: (a) by-pass flow passage means in one of the bodies; (b) a fluid metering member in the chamber in association with one end of the by-pass flow passage means from the compressed fluid in the chamber and operational so that compressed hydraulic fluid is selectively released to the by-pass flow passage means; (c) piston means including relief means to transfer the compressed hydraulic fluid within one of said two hydraulic fluid chamber members to the other of said two hydraulic fluid chamber members across said piston means and thereby move it in the fluid chamber at forces in excess of a predetermined force applicable to said jar, to open the by-pass flow passage means at one end to the compressed hydraulic fluid; (d) said piston means including valve means in the chamber normally closing off the other end of the by-pass flow passage means and shiftable to open so that hydraulic fluid is released from the chamber above said piston means; and (e) hammer and anvil means on said bodies movable into engagement when said fluid metering member and piston valve means open the by-pass passage means in the chamber across said piston means.

Claim 67

The invention of claim 61 wherein said piston means includes seal means sealably and slidably engaged in the chamber to provide cross sectional areas of different size on said piston means responsive to the compressed hydraulic fluid in the chamber for transfer thereof across said piston means.

Claim 68

The invention of claim 61 wherein said flow by-pass means includes substantially constant flow regulator means whereby the compressed hydraulic fluid moves therethrough at a rate within the predetermined pressure differential.

Claim 69

In a hydraulic fishing jar adapted to be run into a well on a fishing string and connected to a fishing tool in the well bore: (a) inner and outer telescopically interengaged bodies; (b) means defining between said bodies a hydraulic fluid chamber; (c) means in the chamber operable upon tensioning the fishing string for telescopic movement of said bodies to compress and apply a predetermined force to the hydraulic fluid in the chamber; (d) there being by-pass flow passage means in one of said bodies; (e) valve means in the chamber for normally closing off one end of the by-pass flow passage means from the compressed fluid in the chamber and responsively activatable to open so that compressed hydraulic fluid is released to the by-pass flow passage means; (f) flow by-pass means to transfer the compressed hydraulic fluid in the chamber and thereby move said fluid in said chamber to engage and move said valve means to open the by-pass flow passage means at one end to the compressed hydraulic fluid upon application of said predetermined force; (g) pressure relief means activatable at forces substantially in excess of said predetermined force to meter fluid therethrough and to transfer fluid pressure resulting from said excess force and within said chamber whereby said valve is engaged and moved to open the by-pass flow passage means at one end of the compressed hydraulic fluid chamber; and (h) hammer and anvil means on said bodies movable into engagement when said valve member and valve means open the by-pass passage means to the chamber across said flow by-pass means.

Claim 70

In a hydraulic fishing jar adapted to be run into a well on a fishing string and connected to a fishing tool in the well bore: (a) inner and outer telescopically interengaged bodies; (b) means defining between said bodies a hydraulic fluid chamber; (c) means in the chamber operable upon tensioning the fishing string for telescopic movement of said bodies to compress and apply a predetermined force to the hydraulic fluid in the chamber; (d) there being by-pass flow passage means in one of said bodies; (e) valve means in the chamber for normally closing off one end of the by-pass flow passage means from the compressed fluid in the chamber and responsively activatable to open so that compressed hydraulic fluid is released to the by-pass flow passage means; (f) flow by-pass means to transfer the compressed hydraulic fluid in the chamber and thereby move said fluid in said chamber to engage and move said valve means to open the by-pass flow passage means at one end to the compressed hydraulic fluid upon application of said predetermined force; (g) pressure relief means activatable at forces substantially in excess of said predetermined force to meter fluid therethrough and to transfer fluid pressure resulting from said excess force and within said chamber whereby said valve is engaged and moved to open the by-pass flow passage means at one end of the compressed hydraulic fluid chamber; and (h) hammer and anvil means on said bodies movable into engagement when said valve member and valve means open the by-pass passage means to the chamber across said flow by-pass means.

Claim 71

The invention of claim 64 wherein said flow by-pass means includes piston means, said piston means having seal means sealably and slidably engaged in the chamber to provide cross sectional areas of different size on said piston means responsive to the compressed hydraulic fluid in the chamber for transfer thereof across said piston means.

Claim 72

The invention of claim 65 wherein said cross sectional areas are of a predetermined relationship for controlling the compressed hydraulic fluid pressure differential across said piston means in the chamber acting to move said piston means.

Claim 73

The invention of claim 65 wherein said piston means is an annular member having top and bottom ends and whereby the cross sectional area defined by said seal means adjacent said bottom piston end is smaller than the cross sectional area defined by said seal means adjacent said top piston end.

Claim 74

The invention of claim 65 including resilient means in the chamber urging said piston means away from said valve means and yieldable as said piston means moves to engage said valve means.

Claim 75

The invention of claim 68 wherein said resilient means urging said piston means away from said valve means also engages said means in the chamber operable upon tensioning the fishing string and is yieldable upon movement of said piston means relative to said means in the chamber operable upon tensioning the fishing string.

Claim 76

The invention of claim 64 wherein said means defining the hydraulic fluid chamber comprises upper and lower seal means between said bodies, one of said seal means being a floating piston for compensating for the pressure of fluid in the well.

Claim 77

The invention of claim 64 wherein said valve means is slidably and sealably carried by said inner body.

Claim 78

The invention of claim 64 wherein said valve means is slidably and sealably carried by said outer body.

Claim 79

The invention of claim 64 wherein said by-pass flow passage means is formed in said outer body.

Claim 80

The invention of claim 64 wherein said by-pass flow passage means is formed in said inner body.

Claim 81

The invention of claim 65 wherein said piston means is slidably and sealably carried in said chamber.

Claim 82

The invention of claim 65 wherein one of said cross sectional areas is defined by seal means between said piston means and inner body and seal means between said piston means and outer body, and the other of said cross sectional areas is defined by seal means between said piston means and outer body and seal means between said piston means and inner body.

Claim 83

The invention of claim 65 wherein said cross sectional areas are of a predetermined relationship for maintaining the compressed hydraulic fluid pressure differential across said piston means within a predetermined range.

Claim 84

The invention of claim 64 wherein said flow by-pass means includes flow regulator means whereby compressed hydraulic fluid is movable therethrough within the predetermined pressure differential.

Claim 85

The invention of claim 78 wherein said flow regulator means is flow reversible.

Claim 86

The invention of claim 65 further comprising a flow reversible element for transmission of fluid in the chamber above said piston means to the chamber below said piston means.

Claim 87

The invention of claim 79 wherein said flow reversible element comprises a check valve.

Claim 88

The invention of claim 64 further comprising a flow reversible element for transmission of fluid in the chamber below the valve means to the chamber above the valve means.