[go: up one dir, main page]

US2370029A - Drum assembly for pumping units - Google Patents

Drum assembly for pumping units Download PDF

Info

Publication number
US2370029A
US2370029A US499153A US49915343A US2370029A US 2370029 A US2370029 A US 2370029A US 499153 A US499153 A US 499153A US 49915343 A US49915343 A US 49915343A US 2370029 A US2370029 A US 2370029A
Authority
US
United States
Prior art keywords
drum
cable
wound
main
assembly
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.)
Expired - Lifetime
Application number
US499153A
Inventor
Gillespie J Gayle
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US499153A priority Critical patent/US2370029A/en
Application granted granted Critical
Publication of US2370029A publication Critical patent/US2370029A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B66HOISTING; LIFTING; HAULING
    • B66DCAPSTANS; WINCHES; TACKLES, e.g. PULLEY BLOCKS; HOISTS
    • B66D1/00Rope, cable, or chain winding mechanisms; Capstans
    • B66D1/02Driving gear
    • B66D1/14Power transmissions between power sources and drums or barrels
    • B66D1/16Power transmissions between power sources and drums or barrels the drums or barrels being freely rotatable, e.g. having a clutch activated independently of a brake
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B66HOISTING; LIFTING; HAULING
    • B66DCAPSTANS; WINCHES; TACKLES, e.g. PULLEY BLOCKS; HOISTS
    • B66D1/00Rope, cable, or chain winding mechanisms; Capstans
    • B66D1/60Rope, cable, or chain winding mechanisms; Capstans adapted for special purposes
    • B66D1/74Capstans
    • B66D1/7442Capstans having a horizontal rotation axis
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00Machine element or mechanism
    • Y10T74/18Mechanical movements
    • Y10T74/18568Reciprocating or oscillating to or from alternating rotary
    • Y10T74/18832Reciprocating or oscillating to or from alternating rotary including flexible drive connector [e.g., belt, chain, strand, etc.]

Definitions

  • This invention relates to long stroke pumping units.
  • An object of this invention is to provide a pumping unit or assembly for use in operating a well pump, embodying a counter-balance weight which is so constructed and arranged that a pair of operating cables may be Wound and unwound on the main drum, and when one or both of the operating cables become worn, additional lengths of cable may be unwound from spare cable drums, the latter being clutched to the main drum and normally rotating therewith but being capable of being individually declutched.
  • a further object of this invention is to provide in a winding drum a continuous groove of maximum length to be available when rods and tubing are to be pulled.
  • Another object of this invention is to provide a drum assembly which includes a main operating drum of conoidal configuration and a spare cable drum at each end of the main drum.
  • Figure 1 is a diagrammatic, view of, a pumping unit constructed according to an embodiment of this invention
  • FIG. 1 is a detail front elevation of the drum assembly
  • Figure 3 is a longitudinal sectional view, taken through the assembly
  • FIG. 4 is a sectional view, taken on they line
  • I-fl designates generally a derrick with which a pumping unit, to be hereinafter described, is
  • the drum assembly is mounted on the base I2 of the derrick, and is operated from a motor -
  • the drum assembly I includes a main drum I5 which is formed of a pair of opposed conoidal drum members I6 and I! having their bases integral and opposing each other. The small ends of the drum members I6 and Il areoutermost and terminate in cylindrical drum portions I8 and I9 respectively.
  • the drum member I5 is former with a spiral groove 20 within which cables 2
  • the main drum I5 is fixedly mounted on a drive shaft 23 which is journalled in bearings 24 and 25 mounted on the base I2.
  • is the service cable which is connected to a pumping rod 26 and the cable 2
  • the cable 22 is the counterweight cable being connected to a counterweight 28, and trained about an upper sheave 29 carried-by the derrick Ill.
  • and 22 are so mounted on the main drum I5 that when cable 2
  • a spare cable drum 30 is loosely mounted on the shaft 23 at one end of the main drum I5,
  • a from thedrum 30 may be unwound from the drum 30 and wound upon the main drum I5, the worn portion of the cable 2
  • the spare service drum 30 may be coupled to the main drum I5 or uncoupled therefrom by means of a compound clutching element, generally designated as 33.
  • the clutching element 33 shown in detail in Figure 6, comprises a sleeve 34 which is keyed on the drum 30, and is slidable endwise on this drum.
  • the sleeve 34 is formed at its inner end with clutch teeth 35 which are adapted to engage in sockets 36 which are formed in the adjacent end of the main drum I5.
  • the sleeve 34 also has formed thereon outwardly ply, and preferably a reduction gearing I4 is infacing clutch teeth 31 which are engageable in 2 sockets 38 formed in the inner side of the spare surface drum 30.
  • the sleeve 34 also is formed with a third series of clutch teeth 39 confronting the teeth 31, and engageable in sockets 40 formed in the outer side of the spare surface drum 30.
  • the sleeve 34 also has formed on the outer end thereof outer clutch teeth 4
  • a grooved collar 44 is formed between the clutching members 39 and 4
  • the teeth 31 and 39 are spaced apart a sufficient distance so that when the teeth '31 are engaged in the sockets 38, the teeth 39 will be disengaged from the sockets or clutch element 4
  • a second spare cable drum 45 is looselymounted on the shaft 23, and has wound thereabout a spare counterweight cable 22a.
  • the inner wall 46 of the spare drum 45 is formed with a'slot 4'I through which the cable 22a extends, and is then wound about the main drum l extending from the right to the left.
  • a clutch member, generally :designated as 48 which is similar in detail to the clutch member 33 shown in Figure 6, is rotatable on the shaft 33 and keyed to drum 45.
  • the adjacent or right end of themain drum I5 is formed with a clutch element 49 withwhich the inner clutch element 50 of the clutch member 48 .is adapted to engage.
  • the inner side of the drum 45 is formed with a clutch element 5
  • the clutch member 52 is oppositely disposed with respect to the clutch member 50.
  • the clutch member54 is also formed on the sleeve 53 and is adapted to engageanouter clutch member 55 formed on the outer side of the drum 45.
  • a grooved shifting collar 53 is formed on the sleeve 53 and the outer end of the sleeve 53 has formed thereon an outer clutch element 5! which is engageable with a stationary clutch element 58 secured by fastening members 59 to the bearing 25.
  • a winding drum assembly-constructed as hereinbefore described will greatly facilitate the pumping operation as a worn length of cable can be easily and quickly removed and a new length of cable substituted therefor.
  • land 451 have a sufficient amount of cable wound thereon to permit one or more additional lengths of operating cable to be unwound therefrom.
  • the two cables, 21 and 22 are connected respectively to the pump-25 and the weight 28.
  • and 22 areon the drum I5 closely adjacent'to each other, and are so arranged that as the drum rotates in one direction, cable 2
  • all .the drums, clutched together, would be rotated in the direction to unwind cable 22 from drum till it extended from storage dlum 45. At this time the storage drum 45 would be unclutched from drum
  • Drums ll, l5 and 30 being fr e from cable 22 would now be rotated in the reverse direction to unwind all of cable 2
  • the unwound portion of .cable 21a would now be wound on the drum l5 by again reversing the direction of rotation of drums ll, I5 and 30.
  • can be out out and the new portion 2 a secured to the pump rod.
  • a is wound on drum l5 storage drum '45 is reclutched to drum II and' cable 22 would be led onto drum H for rewinding thereon.
  • .Cable 22 would be renewed by following the same operations performed in regard to cable 2
  • the storage drum 30 .in renewing cable 22 would be clutched to stationary part 42.
  • a drum assembly for a long stroke pumping unit which comprises a main drum formed of opposed conoidal surfaces positioned with their bases innermost, a drive shaft for said drum, a pair of auxiliary storage drums at opposite ends of said main drum and rotatable therewith, each of said pair of drums having a slot in the inner wall thereof, a cable wound upon each auxiliary drum, each cable passing through its respective slot and wound upon said main drum in a manner whereby the lead-off portions thereof will be .closely adjacent to each other.
  • a drum assembly fora long stroke pumping unit which comprises a main drum formed of opposed conoidal surfaces positioned with their bases innermost, said main drum having a spiral groove in the outer conoidal surfaces thereof, a drive shaft for said drum,'and a pair of auxiliary storage drums at opposite ends of said main drum and rotatable therewith, each of said pair of drums having a slot in the inner wall thereof, a cable wound upon each auxiliary drum, each cable passing through its respective slot and wound upon said main drum with the lead-0E portions of the cables closely adjacent to each other.
  • a drum assembly for along stroke pumping unit which comprises a main drum formed of op cable 22 will follow behind cable 2i,-and willbe wound upon the drum i5.
  • cable.2l will be substantially entirely unwound from drum IS on the left side thereof and will extend from the cylindrical part l8.
  • cable22 will be positioned on the conoidal surface i6 adjacent the small end of this surface.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Storing, Repeated Paying-Out, And Re-Storing Of Elongated Articles (AREA)

Description

Feb 1945- J. G. GILLESPIE DRUM ASSEMBLY FOR PUMPING UNITS 2 Sheets-Sheet 1 Filed Aug. 18, 1943 Feb 9 J. G. GILLESPIE DRUM ASSEMBLY FOR PUMPING UNITS Filed Aug. 18, 1943 2 Sheets-Sheet 2 afigilieap z 'e Patented Feb. 20, 1945 UNITED STATES FATENT QFFICEI DRUM ASSEMBLY FOR PUMPING UNITS J Gayle Gillespie, Gainesville, Tex. Application August 18, 1943, Serial No. 499,153
3 Claims.
This invention relates to long stroke pumping units.
An object of this invention is to provide a pumping unit or assembly for use in operating a well pump, embodying a counter-balance weight which is so constructed and arranged that a pair of operating cables may be Wound and unwound on the main drum, and when one or both of the operating cables become worn, additional lengths of cable may be unwound from spare cable drums, the latter being clutched to the main drum and normally rotating therewith but being capable of being individually declutched.
A further object of this invention is to provide in a winding drum a continuous groove of maximum length to be available when rods and tubing are to be pulled.
Another object of this invention is to provide a drum assembly which includes a main operating drum of conoidal configuration and a spare cable drum at each end of the main drum.
With the foregoing objects in view, and others which may hereinafter more fully appear, the
invention consists of the novel construction,
combination and arrangement of parts, as will be more specifically described, and illustrated in the accompanying drawings, wherein are shown embodiments of the invention, but it is to be understood that changes, variations and modifications may be resorted to which fall within the scope of the invention, as claimed.
In the drawings:
Figure 1 is a diagrammatic, view of, a pumping unit constructed according to an embodiment of this invention;
Figure 2 is a detail front elevation of the drum assembly;
Figure 3 is a longitudinal sectional view, taken through the assembly;
Figure 4 is a sectional view, taken on they line Referring to the drawings the numeral I-fl designates generally a derrick with which a pumping unit, to be hereinafter described, is
-adapted to be used. The drum assembly, generally designated as H, is mounted on the base I2 of the derrick, and is operated from a motor -|3 connected to a source of electric current sup- (Cl. 254-185) I terposed between the motor I3, and the drum assembly II.
The drum assembly I includes a main drum I5 which is formed of a pair of opposed conoidal drum members I6 and I! having their bases integral and opposing each other. The small ends of the drum members I6 and Il areoutermost and terminate in cylindrical drum portions I8 and I9 respectively. The drum member I5 is former with a spiral groove 20 within which cables 2| and 22 are adapted to engage. The main drum I5 is fixedly mounted on a drive shaft 23 which is journalled in bearings 24 and 25 mounted on the base I2. The cable 2| is the service cable which is connected to a pumping rod 26 and the cable 2| extends from the main drum I5 upwardly and is trained about an upper sheave 27. The cable 22 is the counterweight cable being connected to a counterweight 28, and trained about an upper sheave 29 carried-by the derrick Ill.
The two cables 2| and 22 are so mounted on the main drum I5 that when cable 2| is being wound upon the drum 5, the counterweight cable 22 is being unwound from the main drum. A spare cable drum 30 is loosely mounted on the shaft 23 at one end of the main drum I5,
I5, and then a length of cable 2|a from thedrum 30 may be unwound from the drum 30 and wound upon the main drum I5, the worn portion of the cable 2| being cut off and the new cable- 2|a connected to the pumping rod 26.
The spare service drum 30 may be coupled to the main drum I5 or uncoupled therefrom by means of a compound clutching element, generally designated as 33. The clutching element 33, shown in detail in Figure 6, comprises a sleeve 34 which is keyed on the drum 30, and is slidable endwise on this drum. The sleeve 34 is formed at its inner end with clutch teeth 35 which are adapted to engage in sockets 36 which are formed in the adjacent end of the main drum I5. The sleeve 34 also has formed thereon outwardly ply, and preferably a reduction gearing I4 is infacing clutch teeth 31 which are engageable in 2 sockets 38 formed in the inner side of the spare surface drum 30.
The sleeve 34 also is formed with a third series of clutch teeth 39 confronting the teeth 31, and engageable in sockets 40 formed in the outer side of the spare surface drum 30. The sleeve 34 also has formed on the outer end thereof outer clutch teeth 4| which are adapted to engage a complementary stationary clutch member 42 secured by fastening members 43 to the bearing 24. A grooved collar 44 is formed between the clutching members 39 and 4|, and it will be understood that a conventional shifting fork may be engaged with the collar 44 so as to provide for the shifting of the clutch member 33 to the desired-clutching position.
The teeth 31 and 39 are spaced apart a sufficient distance so that when the teeth '31 are engaged in the sockets 38, the teeth 39 will be disengaged from the sockets or clutch element 4|],
' formed on the outer sideof the drum 30.
A second spare cable drum 45 is looselymounted on the shaft 23, and has wound thereabout a spare counterweight cable 22a. The inner wall 46 of the spare drum 45 is formed with a'slot 4'I through which the cable 22a extends, and is then wound about the main drum l extending from the right to the left. A clutch member, generally :designated as 48, which is similar in detail to the clutch member 33 shown in Figure 6, is rotatable on the shaft 33 and keyed to drum 45. The adjacent or right end of themain drum I5 .isformed with a clutch element 49 withwhich the inner clutch element 50 of the clutch member 48 .is adapted to engage. The inner side of the drum 45 is formed with a clutch element 5|, with which the clutch member 52 formed on the sleeve 53 is adapted to engaged. The clutch member 52 is oppositely disposed with respect to the clutch member 50.. The clutch member54 is also formed on the sleeve 53 and is adapted to engageanouter clutch member 55 formed on the outer side of the drum 45. A grooved shifting collar 53 is formed on the sleeve 53 and the outer end of the sleeve 53 has formed thereon an outer clutch element 5! which is engageable with a stationary clutch element 58 secured by fastening members 59 to the bearing 25.
A winding drum assembly-constructed as hereinbefore described will greatly facilitate the pumping operation as a worn length of cable can be easily and quickly removed and a new length of cable substituted therefor. Itwill be understood that the spare drums v3|land 451have a sufficient amount of cable wound thereon to permit one or more additional lengths of operating cable to be unwound therefrom. In the use and operation of this assembly the two cables, 21 and 22, are connected respectively to the pump-25 and the weight 28. The cables 2| and 22 areon the drum I5 closely adjacent'to each other, and are so arranged that as the drum rotates in one direction, cable 2| will unwind therefrom, and
during the initial upward movement. After the pumping rod 26 begins its upward movement this movement will be speeded up during the time that cable 2| is being wound on the large inner end of the drum portion l6 and counterweight 28 will gradually reduce its movement downwardly as cable 22 moves to the right or small end of drum member l1.
With both drums clutched to the main drum and renewing cable portion 2| all .the drums, clutched together, would be rotated in the direction to unwind cable 22 from drum till it extended from storage dlum 45. At this time the storage drum 45 would be unclutched from drum |5 and clutched to the standard 25 to hold storage'drum 45 and cable 22 stationary. Drums ll, l5 and 30 being fr e from cable 22 would now be rotated in the reverse direction to unwind all of cable 2| and a sufficient amount of cable 2 la from storage drum 30 to renew the worn portion 2|. The unwound portion of .cable 21a would now be wound on the drum l5 by again reversing the direction of rotation of drums ll, I5 and 30. The worn cable portion 2| can be out out and the new portion 2 a secured to the pump rod. When a sufficient amount of cable 2|a is wound on drum l5 storage drum '45 is reclutched to drum II and' cable 22 would be led onto drum H for rewinding thereon. .Cable 22 would be renewed by following the same operations performed in regard to cable 2|. The storage drum 30 .in renewing cable 22 would be clutched to stationary part 42.
I claim:
1. A drum assembly for a long stroke pumping unit which comprises a main drum formed of opposed conoidal surfaces positioned with their bases innermost, a drive shaft for said drum, a pair of auxiliary storage drums at opposite ends of said main drum and rotatable therewith, each of said pair of drums having a slot in the inner wall thereof, a cable wound upon each auxiliary drum, each cable passing through its respective slot and wound upon said main drum in a manner whereby the lead-off portions thereof will be .closely adjacent to each other.
2. A drum assembly fora long stroke pumping unit which comprises a main drum formed of opposed conoidal surfaces positioned with their bases innermost, said main drum having a spiral groove in the outer conoidal surfaces thereof, a drive shaft for said drum,'and a pair of auxiliary storage drums at opposite ends of said main drum and rotatable therewith, each of said pair of drums having a slot in the inner wall thereof, a cable wound upon each auxiliary drum, each cable passing through its respective slot and wound upon said main drum with the lead-0E portions of the cables closely adjacent to each other.
3. A drum assembly for along stroke pumping unit which comprises a main drum formed of op cable 22 will follow behind cable 2i,-and willbe wound upon the drum i5. At the-time the pumping rod 26 is at its lowermost position cable.2l will be substantially entirely unwound from drum IS on the left side thereof and will extend from the cylindrical part l8. At this time cable22 will be positioned on the conoidal surface i6 adjacent the small end of this surface. When the drum I5 is rotated in a reverse direction 'to raise'the pumping rod 26, cable 2| being extended at this time from the small end of drum l5 will not'place an undue'tensional strain on the drum or shaft posed conoidal surfaces positioned with their bases innermost, a driveshaft for said drum, a pair of auxiliary storage drums at the opposite small ends of said main drum, and loose on said shaft, each of said pair of drums including an inner wall having a slot therein, a cable wound upon each auxiliary drum, each cable passing through its respective slot and wound upon said main drum in a manner whereby the lead-off portions thereof will be closely adjacent to each other, and clutch means for selectively clutching said auxiliary drumsto said main drum.
' -J 'GAYLE'GILLESPIE.
US499153A 1943-08-18 1943-08-18 Drum assembly for pumping units Expired - Lifetime US2370029A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US499153A US2370029A (en) 1943-08-18 1943-08-18 Drum assembly for pumping units

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US499153A US2370029A (en) 1943-08-18 1943-08-18 Drum assembly for pumping units

Publications (1)

Publication Number Publication Date
US2370029A true US2370029A (en) 1945-02-20

Family

ID=23984063

Family Applications (1)

Application Number Title Priority Date Filing Date
US499153A Expired - Lifetime US2370029A (en) 1943-08-18 1943-08-18 Drum assembly for pumping units

Country Status (1)

Country Link
US (1) US2370029A (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3229960A (en) * 1962-08-20 1966-01-18 Jean D Loomis Hoisting apparatus for well rig
US3743249A (en) * 1970-04-30 1973-07-03 Shell Oil Co Heave compensator
US3784166A (en) * 1971-12-01 1974-01-08 Terra Marine Scoop Co Inc Level wind drum
US3853205A (en) * 1970-03-23 1974-12-10 Task Corp Load accelerating and decelerating pulley means
US4062640A (en) * 1976-09-24 1977-12-13 Bethlehem Steel Corporation Method and means for controlling long stroke pumping units
US4076218A (en) * 1976-09-24 1978-02-28 Bethlehem Steel Corporation Longstroke pumping apparatus for oil wells
US4534233A (en) * 1983-04-18 1985-08-13 Nippon Cable System Inc. Wire-driving device for window regulator
US4719811A (en) * 1985-02-25 1988-01-19 Rota-Flex Corporation Well pumping unit with counterweight
US5735170A (en) * 1995-09-11 1998-04-07 Bales; Donald R. Pumping unit with dynamic fluid ballast
US20070098575A1 (en) * 2005-10-28 2007-05-03 Xiuting Han Pumping system
US20140326936A1 (en) * 2013-05-03 2014-11-06 Illinois Tool Works Inc. Winch having adjustable initial mechanical advantage
US11390500B2 (en) * 2019-04-26 2022-07-19 Engineered Hardware, Llc Drive drum for overhead doors

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3229960A (en) * 1962-08-20 1966-01-18 Jean D Loomis Hoisting apparatus for well rig
US3853205A (en) * 1970-03-23 1974-12-10 Task Corp Load accelerating and decelerating pulley means
US3743249A (en) * 1970-04-30 1973-07-03 Shell Oil Co Heave compensator
US3784166A (en) * 1971-12-01 1974-01-08 Terra Marine Scoop Co Inc Level wind drum
US4062640A (en) * 1976-09-24 1977-12-13 Bethlehem Steel Corporation Method and means for controlling long stroke pumping units
US4076218A (en) * 1976-09-24 1978-02-28 Bethlehem Steel Corporation Longstroke pumping apparatus for oil wells
US4534233A (en) * 1983-04-18 1985-08-13 Nippon Cable System Inc. Wire-driving device for window regulator
US4719811A (en) * 1985-02-25 1988-01-19 Rota-Flex Corporation Well pumping unit with counterweight
US5735170A (en) * 1995-09-11 1998-04-07 Bales; Donald R. Pumping unit with dynamic fluid ballast
US20070098575A1 (en) * 2005-10-28 2007-05-03 Xiuting Han Pumping system
US7635022B2 (en) * 2005-10-28 2009-12-22 Petrochina Company Limited Pumping system
US20140326936A1 (en) * 2013-05-03 2014-11-06 Illinois Tool Works Inc. Winch having adjustable initial mechanical advantage
US9586794B2 (en) * 2013-05-03 2017-03-07 Illinois Tool Works Inc. Winch having adjustable initial mechanical advantage
US11390500B2 (en) * 2019-04-26 2022-07-19 Engineered Hardware, Llc Drive drum for overhead doors

Similar Documents

Publication Publication Date Title
US2370029A (en) Drum assembly for pumping units
GB1411177A (en) Tower cranes
US1689016A (en) Windlass construction
US2450257A (en) Reel mechanism
US2274168A (en) Draw works
US2505088A (en) Well-drilling rig
US1652492A (en) Electric motor and transmitter unit
US1555094A (en) Hoist
US2548270A (en) Hoist
US1792467A (en) Hoisting mechanism
US1446562A (en) Portable hoist
US1943453A (en) Balancer
US1775707A (en) Reeling machine for cables
US1476941A (en) Electric-cable-winding mechanism
US1570116A (en) Line guide
US1461637A (en) Combined winch and support therefor
US2165350A (en) Control for four-speed portable drilling machines
US2420990A (en) Portable excavator
SU38073A1 (en) Device for automatically feeding a drilling tool to a bottom hole
US2247606A (en) Draw works
US2170504A (en) Winch
US1445152A (en) Rotating mechanism
US1792115A (en) Hoisting mechanism
CN222042500U (en) A hoisting device that is easy to maintain
US1543173A (en) Screw gearing