Patent WO2000006027A2 successfully refreshed from Google Patents.
US3867989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulldown mechanism for rotary drill apparatus
Assignee: Gardner Denver Inc
•
Filing: 1973-05-21
•
Granted: 1975-02-25
•
Expires: 1993-05-21
Abstract
Abstract A frame arranged to traverse a mast on a rotary drill apparatus for exerting an axial feed or pulldown force on a drill pipe and bit assembly and characterized by a pair of rotatable shafts each having two spaced apart pinions mounted thereon which are engaged with parallel gear racks mounted on the mast. The pinion shafts each have a sprocket mounted thereon driven by an endless chain connected to pulldown drive means mounted on the main deck of the apparatus. The pulldown chains are equally tensioned by a pair of hydraulic chain tensioning devices so that equal torque is exerted on the pinion shafts. The pinion shafts are spring mounted on the pulldown frame to compensate for misalignment of the gear racks with respect to each other.
Inventors
- 👤 Robert W Hisey
- 👤 Ray M Mitchhart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:32
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/02; E21B7/022; E21B19/00; E21B19/08; E21B19/084; E21B7/021
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
322 words
In an earth drilling apparatus: an elongated upstanding mast; a rotatable drill string including at least one elongated drill pipe section; rotary drive means engaged with said drill pipe for rotating said drill string; a frame including coupling means mounted thereon and connected to one end of said drill pipe and mounted on said mast for linear movement therealong to transmit pulldown and hoisting forces to said drill string, first and second rotatable shafts independently mounted on said frame in spaced apart and parallel relationship and including means positively engaged with means mounted on said mast for effecting movement of said frame along said mast to exert a pulldown force on said drill string in response to rotation of said shafts; a pair of elongated flexible chains forming closed loops and respectively drivingly engaged with sprockets fixed on said shafts and on a drive shaft mounted on said apparatus; a pair of tensioning devices, one engaged with each chain of said pair, each tensioning device including chain engaging means mounted for movement on a frame and a pressure fluid cylinder connected for biasing said chain engaging means to apply tensioning forces to said chain, and said cylinders are interconnected so that the fluid pressure in said cylinders provides equal biasing forces on said chain engaging means to thereby apply substantially equal tensioning forces to each of said chains and substantially equal driving torque on said shafts; and a second pair of tensioning devices, one tensioning device engaged with each chain of said pair, each tensioning device of said second pair including rotatable chain engaging means disposed for movement on a frame and pressure fluid cylinder means for engaging said rotatable chain engaging means to apply chain tensioning forces thereto and adapted to permit movement of said rotatable chain engaging means in response to a change in chain path length between said drive shaft and said chain engaging means on said tensioning devices.
Claim 2
Dependent Claim
322 words
In an earth drilling apparatus: an elongated upstanding mast; a rotatable drill string including at least one elongated drill pipe section; rotary drive means engaged with said drill pipe for rotating said drill string; a frame including coupling means mounted thereon and connected to one end of said drill pipe and mounted on said mast for linear movement therealong to transmit pulldown and hoisting forces to said drill string, first and second rotatable shafts independently mounted on said frame in spaced apart and parallel relationship and including means positively engaged with means mounted on said mast for effecting movement of said frame along said mast to exert a pulldown force on said drill string in response to rotation of said shafts; a pair of elongated flexible chains forming closed loops and respectively drivingly engaged with sprockets fixed on said shafts and on a drive shaft mounted on said apparatus; a pair of tensioning devices, one engaged with each chain of said pair, each tensioning device including chain engaging means mounted for movement on a frame and a pressure fluid cylinder connected for biasing said chain engaging means to apply tensioning forces to said chain, and said cylinders are interconnected so that the fluid pressure in said cylinders provides equal biasing forces on said chain engaging means to thereby apply substantially equal tensioning forces to each of said chains and substantially equal driving torque on said shafts; and a second pair of tensioning devices, one tensioning device engaged with each chain of said pair, each tensioning device of said second pair including rotatable chain engaging means disposed for movement on a frame and pressure fluid cylinder means for engaging said rotatable chain engaging means to apply chain tensioning forces thereto and adapted to permit movement of said rotatable chain engaging means in response to a change in chain path length between said drive shaft and said chain engaging means on said tensioning devices.
Claim 3
Dependent Claim
177 words
In an earth drilling apparatus: an elongated upstanding mast including a pair of spaced apart longitudinal members each supporting a gear rack; a rotatable drill string including at least one elongated drill pipe section; rotary drive means engaged with said drill pipe for rotating said drill string; and, a frame connected to one end of said drill pipe and mounted on said mast for linear movement therealong to transmit pulldown and hoisting forces to said drill string, said frame including first and second rotatable means independently mounted thereon, said first rotatable means including a pair of pinions, one pinion engaged with each rack, and said rotatable means including a pair of pinions, one pinion engaged with each rack for effecting longitudinal movement of said frame along said mast, and a roller truck assembly including rollers disposed to roll along said longitudinal members on respective track surfaces parallel and opposed to said gear racks, said truck assembly including spring means interconnecting said truck assembly and said frame for resiliently biasing said pinions into engagement with said gear racks.
Claim 4
Dependent Claim
177 words
In an earth drilling apparatus: an elongated upstanding mast including a pair of spaced apart longitudinal members each supporting a gear rack; a rotatable drill string including at least one elongated drill pipe section; rotary drive means engaged with said drill pipe for rotating said drill string; and, a frame connected to one end of said drill pipe and mounted on said mast for linear movement therealong to transmit pulldown and hoisting forces to said drill string, said frame including first and second rotatable means independently mounted thereon, said first rotatable means including a pair of pinions, one pinion engaged with each rack, and said rotatable means including a pair of pinions, one pinion engaged with each rack for effecting longitudinal movement of said frame along said mast, and a roller truck assembly including rollers disposed to roll along said longitudinal members on respective track surfaces parallel and opposed to said gear racks, said truck assembly including spring means interconnecting said truck assembly and said frame for resiliently biasing said pinions into engagement with said gear racks.
Claim 5
Dependent Claim
142 words
In an earth drilling apparatus: an elongated upstanding mast; a rotatable drill string including at least one elongated drill pipe section; rotary drive means engaged with said drill pipe for rotating said drill string; and, traverse means connected to one end of said drill pipe and mounted on said mast for linear movement therealong to transmit pulldown and hoisting forces to said drill string, said traverse means including a frame, first and second rotatable shafts, each shaft including a pair of pinions mounted thereon and positively engaged with spaced apart longitudinal gear racks mounted on said mast for effecting movement of said traverse means along said mast to exert a pulldown force on said drill string in response to rotation of said shafts, and resilient mounting means supporting said shafts independently on said frame for limited movement with respect to said frame.
Claim 6
Dependent Claim
142 words
In an earth drilling apparatus: an elongated upstanding mast; a rotatable drill string including at least one elongated drill pipe section; rotary drive means engaged with said drill pipe for rotating said drill string; and, traverse means connected to one end of said drill pipe and mounted on said mast for linear movement therealong to transmit pulldown and hoisting forces to said drill string, said traverse means including a frame, first and second rotatable shafts, each shaft including a pair of pinions mounted thereon and positively engaged with spaced apart longitudinal gear racks mounted on said mast for effecting movement of said traverse means along said mast to exert a pulldown force on said drill string in response to rotation of said shafts, and resilient mounting means supporting said shafts independently on said frame for limited movement with respect to said frame.
Claim 7
Dependent Claim
73 words
The invention set forth in claim 3 wherein: said traverse means includes spaced apart bearing means for rotatably supporting said first and second shafts respectively on said frame and said resilient mounting means includes spring means engaged with said bearing means and said frame for supporting said first and second shafts for movement with respect to said frame in response to a predetermined pulldown force being transmitted from said mast to said frame.
Claim 8
Dependent Claim
55 words
The invention set forth in clain 4 wherein: said first and second shafts each include spaced apart bearing support housings supported by said frame and disposed adjacent said pinions, and said spring means comprises plural spring assemblies disposed in engagement with each of said housings for resiliently urging said housings in engagement with said frame.
Claim 9
Dependent Claim
55 words
The invention set forth in clain 4 wherein: said first and second shafts each include spaced apart bearing support housings supported by said frame and disposed adjacent said pinions, and said spring means comprises plural spring assemblies disposed in engagement with each of said housings for resiliently urging said housings in engagement with said frame.
Claim 10
Dependent Claim
57 words
The invention set forth in claim 5 wherein: said spring assemblies are formed to provide a preload force acting on each housing of said first and second shafts which is substantially equal to one fourth of a predetermined maximum pulldown force to be transmitted from said mast to said traverse frame without deflection of said spring assemblies.
Claim 11
Dependent Claim
14 words
The invention set forth in claim 6 wherein: said spring assemblies comprise Belleville springs.
Claim 12
Dependent Claim
60 words
The invention set forth in claim 7 wherein: said Belleville springs are formed to provide for movement of said shafts with respect to said frame when a predetermined tooth load on said pinions corresponding to the preload force acting on the adjacent spring assembly is reached, said movement taking place without substantially any additional load being imposed on said pinions.
Claim 13
Dependent Claim
37 words
The invention set forth in claim 6 wherein: at least one of said spring assemblies is forMed to undergo greater deflection than the remainder of said spring assemblies for a given force greater than the preload force.
Claim 14
Dependent Claim
178 words
In an earth drilling apparatus: an elongated mast including a pair of spaced apart gear racks thereon; a rotatable drill string including at least one elongated drill pipe section; means drivably engaged with said drill pipe section for rotating said drill string; traverse means connected to one end of said drill string and disposed on said mast for linear movement therealong to transmit pulldown and hoisting forces to said drill string, said traverse means comprising a frame, and first and second rotatable shafts mounted on said frame and including respectively, on each shaft, a pair of pinions engaged respectively with said spaced apart gear racks; drive means comprising a pair of elongated flexible chains, each chain forming a continuous closed loop and being engaged with drive sprocket means mounted on said apparatus, one of said chains being engaged with a sprocket fixed on said first shaft and the other chain being engaged with a sprocket fixed on said second shaft; and, means for causing said chains to exert substantially equal driving torque on said first and second shafts.
Claim 15
Dependent Claim
178 words
In an earth drilling apparatus: an elongated mast including a pair of spaced apart gear racks thereon; a rotatable drill string including at least one elongated drill pipe section; means drivably engaged with said drill pipe section for rotating said drill string; traverse means connected to one end of said drill string and disposed on said mast for linear movement therealong to transmit pulldown and hoisting forces to said drill string, said traverse means comprising a frame, and first and second rotatable shafts mounted on said frame and including respectively, on each shaft, a pair of pinions engaged respectively with said spaced apart gear racks; drive means comprising a pair of elongated flexible chains, each chain forming a continuous closed loop and being engaged with drive sprocket means mounted on said apparatus, one of said chains being engaged with a sprocket fixed on said first shaft and the other chain being engaged with a sprocket fixed on said second shaft; and, means for causing said chains to exert substantially equal driving torque on said first and second shafts.
Claim 16
Dependent Claim
52 words
The invention set forth in claim 10 wherein: said means for causing said claims to exert substantially equal driving torque on said first and second shafts comprises a pair of tensioning devices engaged with the respective chains of said pair and operable to exert substantially equal chain tensioning forces on said chains.
Claim 17
Dependent Claim
65 words
The invention set forth in claim 11 wherein: said tensioning devices are each characterized by chain engaging means mounted for movement on a frame and a pressure fluid cylinder connected for biasing said chain engaging means to apply tensioning forces to said chain, and said cylinders are interconnected so that the fluid pressure in said cylinders provides equal biasing forces on said chain engaging means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |