US1551837A - Tower erection derrick - Google Patents

Tower erection derrick Download PDF

Info

Publication number
US1551837A
US1551837A US452374A US45237421A US1551837A US 1551837 A US1551837 A US 1551837A US 452374 A US452374 A US 452374A US 45237421 A US45237421 A US 45237421A US 1551837 A US1551837 A US 1551837A
Authority
US
United States
Prior art keywords
tower
members
extending
erection
erecting device
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
US452374A
Inventor
Joseph H Mosel
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.)
LAKEWOOD ENGINEERING Co
Original Assignee
LAKEWOOD ENGINEERING Co
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 LAKEWOOD ENGINEERING Co filed Critical LAKEWOOD ENGINEERING Co
Priority to US452374A priority Critical patent/US1551837A/en
Application granted granted Critical
Publication of US1551837A publication Critical patent/US1551837A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • EFIXED CONSTRUCTIONS
    • E04BUILDING
    • E04HBUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
    • E04H12/00Towers; Masts or poles; Chimney stacks; Water-towers; Methods of erecting such structures
    • E04H12/34Arrangements for erecting or lowering towers, masts, poles, chimney stacks, or the like
    • 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
    • Y10T29/00Metal working
    • Y10T29/49Method of mechanical manufacture
    • Y10T29/49616Structural member making
    • Y10T29/49623Static structure, e.g., a building component
    • Y10T29/49631Columnar member

Definitions

  • the present invention relates to an apas an example of suchltowers, mention may befina-de of towers used in the construction of buildings or similar lstructures where concrete mixed on the ground. is elevated.
  • Vbe brieiiy describedk as comprising an erectionr device vwhich vis movedy upward upon the tower construction 25.
  • the invention further ⁇ contemplates an erection device whichfupon completion Aof the tower kmay be'lowered, ⁇ preferably withinthe tower to the ground and there dis- 40 assembled; 'i l the invention will" tionV proceeds.
  • Fig.. l is an elevation showing. an erecting device of the present invention in lcooperating "position ywith the n tower which is being erected.
  • Fig. 2 1s aAv ⁇ side elevation.
  • Fig. 3 is a plan view sub,-
  • Fig. 5 is an elevation showing a vunit whichforms a part'of the tower construction.
  • Fig. k6 k1s an elevation paratus usefullin the erection of towers, and*r specific as'the same is erected; "Thiserection unit Various features and further objects ofv panying drawings forming a part of this,I
  • lindicates what may broadly be termed a tower which is made of suitable structural y elements which in the present instance' are largely angle irons suitably held together by bolts and bracedv by ianarods. f
  • Figs and 6 there are illustrated two units which enter into the particular tower structure which isillustrated in the drawings.
  • the unity 2 illustrated is such as is used to formthe front and rear elements of a -tower section.
  • Fig. 6 represents ra unitrwhich may form one side ofthe tower section tanda. unit similar to that shown in Fig. 6 may formthe other side.
  • the j erecting device whichk forms ⁇ the real subject *matter oftheinvention has transversely 'extending angle bars and 6 andsecured to .these members 5 and 6 adjacent the purposes these j guides vmay right angles t0 the members and 6 arey what we. may term vplatform members 7 and 8, becausethese members adjacent one endk are adapted to supporta platform 9, this platform servingV as standing'froom for workmen f who arev erecting thetower.
  • lSpecuredto the ends of the members 7 and 8 are upwardly extending members 10 and 11, and 10a and 1l ⁇ which converge and at Vtheir( upper ends are joined tokreach other by means, of plates such as 'indicatedjatyl Secured,
  • transversely extending members preferably made of angle iron such as indicated at 13, and these members 13 at their end portions support platforms such as indicated at 14;, these serving as standing room for the workmen erecting the tower.
  • angle iron pieces such as indicated at 15 which connect the members 10, 11, 10a and 11, for the purpose of strengthening the structure and these members also serve as a means for climbing from the platform 9 up to the platform 14.
  • These guide members which have been described are in position to cooperate with the guide members 8 and l which form parts of the tower construction.
  • each of the dogs comprises two spaced members 21" and 21c such as shown in Fig. 3 and these members just mentioned are joined by a rod 22 which lies above the transversely extending members 5 and 6.
  • the lower, or outer ends of the dogs are of sul'licientlength to rest upon the upper portion of the tower construction, in the present instance resting upon the top angle iron of the uppermost tower section which has been assembled, and these dogs serve to support the erecting device upon the tower.
  • .Set screws such as indicated at 23 may be threaded through suitable openings in the guide members 16, as well as through the other guide members which may be moved into position against the guides 4t on the tower, and by locating these set screws such as 28 for instance, at the extremities of the guide members 16, 17, 16a and 17, the erect-ion device will be held against vibra-ting movement.
  • a member 24 Extending centrally through the erect-ion device is a member 24.
  • This element is preferably a hollow pipe-like structure, at its lower end there is a collar 2% which bears against a thrust plate 25 which is supported on the members 5 and 6.
  • This thrust plate has a central opening through which the member 2% extends.
  • the member 24 extends through an opening in the plate 12 which joins the upper ends of the members 10, 11, 1()a and 11u as above described, this construction being for the purpose of forming an upper guide and retention member for the member 24.
  • This hoisting mechanism in the present instance comprises transversely extending angle members 25 and 25a. These angle members are pivotally mounted upon the member 211 as indicated at 26. At the ends otl the members 25 and 25il there are diagonally extending straps 27 and 27a and oppositely disposed with respect thereto is a pair o1 straps one of which is indicated at 28. These straps at their lower ends are secured to suitable plates 29 which are in turn connected to the member 241 just above the plate 12.
  • the ends'o't the straps 27 and 27a and the oppositely.disposed straps 28 and 28a are so arranged that the connection with the plate 29 may be removed so that the whole structure which has just been described, to-wit, the members 25, 25a, 27 and 27'L1 and the pair of oppositely disposed straps 28 and 28 may move pivotally about the point 26.
  • This construction is purposeful in that it permits l the entireferecting device tovv be moved downwardly through the tower afterthe complete erection thereof, which ⁇ would otherwise notbe-possible due to the yfact thatthe member 25.atthe end of theiiiember 2llefrtends beyond the sides of they tower.
  • Fig. 1 we may assume that the erecting 'apparatus has'just been elevated upon a completed section of the tower, and in this position the next secbeen . tion of the tower Vmay be erected by the workmen from the platforms 9 and 14, utilizing the hoisting apparatus before described to elevate the sections of the tower which are to be placed.
  • the pulleysf38 and 39 will .be attached to the upper part of the tower section which has been completed, v andl by this ⁇ means the entire erecting device may beraised as a unit.
  • Vlien the erecting device is elevated as kdescribed the platforms 9 and 14 and the hoisting mechanism associated; with t-he erecting device are all abovethe completed pordisengaged from the plates 2,9 whichV per- Y mits these members together with thel meinbers25A and ⁇ 25a to assume the positionshown in dotted lines in Fig. 1 in which position the entire erecting device may be lowered within the tower, to the lower endlof the tower and there disassembled and removed.
  • said erection device having 'hoisting means above said platform, and means for securing said erection device the tower.
  • An erecting device adapted yfor usekin erecting a tower, comprising a frame having iis .y
  • An erecting device adapted for use in erecting a tower, comprising a frame having a transversely extending central member, depending guide members from the central members, braces connecting the lower ends ot the said guide members with the said central member, converging diagonal members extending ⁇ above the central member, means for retaining the upper ends of said converging members, a platform supported from the said converging members, a tubular member extending centrally with respect to the frame and rotatably supported by said transverse member at the central portion of the frame, means at the upper ends of the converging members for retaining the said tubular member and a ⁇ hoisting member mounted upon the said tubular member.
  • An erecting device adapted for use in erecting a tower, comprising a frame having a transversely extending central member, depending guide members from the central member, braces connecting the lower ends of the said guide members with the said central member, converging members extending above the cent-ral member, means for retaining the upper ends of said diagonal members and a platform supported from the said converging members, a tubular member extending centrally with respect to the frame and supported by the transverse member at the central portion of the frame and supported for rotation, means atthe upper ends ot' the converging members for supporting the said tubular member, and transversely extending member pivotally mounted upon the upper end of said tubular member, tie rod members connecting the opposite ends of the said transversely extending member to the tubular member, the said tie rods being detachable, whereby the transversely extending member may be turned about its pivot7 pulleys mounted at the opposite ends of the transversely extending member and a pulley mounted upon the tubular member and adjacent thereto

Description

l, 1925. K v J; H. Most-:L
TOWER ERECTION nannten Filed March 14, '1921 n 2 Sheng-sheet 1 n 1,551,837 J. H. MOSEL TOWER ERECTIONDERRICK Filed March 14, 1921 2 Sheets-Sheet 2 Patented Sept. 1, 1925.
. A j 1,551,831 g :STATES- PATENT OFFICE* JOSEPH H. MOSEL, 0F "LAKEWOOD, OHIO, 'ASSIGNOR 'IO-*THE LAKETOOD ENGINEERING i CO'MPANY, OF CLEVELAND, OHIO, A CORPORATION 0F OHIO.v i
TOWER ERECTION DERRICK.Y
Application filed. March 141921. Serial No. 452,374.
and useful Improvement in Tower Erection Derricks, yof'which the following is affull, clear., `and exact description. v
The present invention relates to an apas an example of suchltowers, mention may befina-de of towers used in the construction of buildings or similar lstructures where concrete mixed on the ground. is elevated.
15 on 'thejtower to a given height Yand distributed through chutes to `different parts of thefconstruction which is beingr built.V Mention of these particular towers 1s madev Y structionof the particular tower which 1s without in any waylli'miting theV invention, as the invention -is broader than .the
useas will` latery appear. f
.',llhe invention may Vbe brieiiy describedk as comprising an erectionr device vwhich vis movedy upward upon the tower construction 25.
is provided with platforms upon which workmen mayfstand for the purpose of securing the parts of the tower in kthe process of erection and additionally lthe erection. device is provided with a'hoist` mechanism 1 by which the material entering finto. the
construction of the tower maybe hoistedfrom thegronnd and elevated to properpo#` sition for its incorporation into the tower structure.
The invention further` contemplates an erection device whichfupon completion Aof the tower kmay be'lowered,` preferably withinthe tower to the ground and there dis- 40 assembled; 'i l the invention will" tionV proceeds. c
Reference shouldjbe had to the accomappear as the descrip'-` speciiication, in which Fig.. l is an elevation showing. an erecting device of the present invention in lcooperating "position ywith the n tower which is being erected. Fig. 2 1s aAv `side elevation. Fig. 3 isa plan view sub,-
stantiallyalong fthe line of Fig. l.'` Fig. 4.,is asectional plan showing a detail offconstruction.l Fig. 5 is an elevation showing a vunit whichforms a part'of the tower construction., Fig. k6 k1s `an elevation paratus usefullin the erection of towers, and*r specific as'the same is erected; "Thiserection unit Various features and further objects ofv panying drawings forming a part of this,I
showing another unit-of the tower construction. c
Referring to the drawings, lindicates what may broadly be termed a tower which is made of suitable structural y elements which in the present instance' are largely angle irons suitably held together by bolts and bracedv by tiefrods. f
`In Figs and 6 there are illustrated two units which enter into the particular tower structure which isillustrated in the drawings. In Fig.. 5" the unity 2 illustrated is such as is used to formthe front and rear elements of a -tower section. f Fig. 6 represents ra unitrwhich may form one side ofthe tower section tanda. unit similar to that shown in Fig. 6 may formthe other side. These vsections which enter into the con- ,towerv'are for the piurposelofV forming guid- Y ingelements for an elevator or `bucket which is adapted, to be raised and lowered for the purpose .0f elevating buildingvmaterial to bey usedin the construction of the building.
Itwill be obvious that where the tower is usedfor other be omitted. V,
The j erecting device whichk forms `the real subject *matter oftheinvention has transversely 'extending angle bars and 6 andsecured to .these members 5 and 6 adjacent the purposes these j guides vmay right angles t0 the members and 6 arey what we. may term vplatform members 7 and 8, becausethese members adjacent one endk are adapted to supporta platform 9, this platform servingV as standing'froom for workmen f who arev erecting thetower. lSpecuredto the ends of the members 7 and 8 are upwardly extending members 10 and 11, and 10a and 1l` which converge and at Vtheir( upper ends are joined tokreach other by means, of plates such as 'indicatedjatyl Secured,
ends thereof andextending in a direction at bers 19.
to the upwardly extending members 10, 11, 10'bl and 11, are transversely extending members, preferably made of angle iron such as indicated at 13, and these members 13 at their end portions support platforms such as indicated at 14;, these serving as standing room for the workmen erecting the tower.
There are also other angle iron pieces such as indicated at 15 which connect the members 10, 11, 10a and 11, for the purpose of strengthening the structure and these members also serve as a means for climbing from the platform 9 up to the platform 14. At the ends of the members 5 and 6 as shown in Fig. 8 there are vertically extending members 16, 17 7 16aM and 17a. These members at one of their ends are attached by suitable means t0` the transversely extending members 5 and 6 and to the members 7 and 8. These guide members which have been described are in position to cooperate with the guide members 8 and l which form parts of the tower construction. That is to say, they are suiiciently close to the tower guide members so that as the erecting device is raised or lowered the device is guided by the cooperation between t-he guide members 8 and l and the members 16, 17, 16a and 17 a carried by the erecting device. These vertically extending guide members at their lower ends are joined by plates indicated at 18 in Fig. 1 and extending between the plates 18 are transversely extending mem- Furthermore there are members extending diagonally upward from the plates 18 such as indicated at 2O in Fig. 1 which extend from the members 7 and 8, or rather from the plates such as 8a, to which they are secured and which plates are in turn secured to the members 7 and 8. These diagonally upward extending members 2O at their lower ends connect with the plates 18, thus forming a rigid connecting means between the lower ends of the guide members 16, 17, 16EL and 17EL and the members 5, .6, 7, and 8.
Pivoted. upon the vertical guide members 16, 17,16 and 17a are supporting dogs indicated at 21, there being two such dogs which are oppositely disposed and the dogs are pivoted to the erecting device as indicated at 21a. Each of the dogs comprises two spaced members 21" and 21c such as shown in Fig. 3 and these members just mentioned are joined by a rod 22 which lies above the transversely extending members 5 and 6. The lower, or outer ends of the dogs are of sul'licientlength to rest upon the upper portion of the tower construction, in the present instance resting upon the top angle iron of the uppermost tower section which has been assembled, and these dogs serve to support the erecting device upon the tower. lt will be apparent that when, as later described, the erecting device is ele- Vated through tower sections which have been newly added the cuter ends of the dogs will be pushed down and out of the way if the outer ends engage with parts of the tower structure, and due to the Jfact that there is greater weight at the inner ends of the dogs where the rods 22 are situated, the
natural tendency ot the dogs will be to assume the position shown in Fig. 2.
In order to hold the erection device from slight movement or vibration when cooperating with a tower, means may be provided for this purpose, and in Fig. l one way is indicated in which this may be accomplished. .Set screws such as indicated at 23 may be threaded through suitable openings in the guide members 16, as well as through the other guide members which may be moved into position against the guides 4t on the tower, and by locating these set screws such as 28 for instance, at the extremities of the guide members 16, 17, 16a and 17, the erect-ion device will be held against vibra-ting movement.
Extending centrally through the erect-ion device is a member 24. This element is preferably a hollow pipe-like structure, at its lower end there is a collar 2% which bears against a thrust plate 25 which is supported on the members 5 and 6. This thrust plate has a central opening through which the member 2% extends. This construction described ser *es to mount the end of the member 24 in a fashion which permits rotation of this member. The member 24 extends through an opening in the plate 12 which joins the upper ends of the members 10, 11, 1()a and 11u as above described, this construction being for the purpose of forming an upper guide and retention member for the member 24.
Upon the upper end of the member 24 which extends beyond the plate 12 there is mounted a suitable hoisting mechanism. This hoisting mechanism in the present instance comprises transversely extending angle members 25 and 25a. These angle members are pivotally mounted upon the member 211 as indicated at 26. At the ends otl the members 25 and 25il there are diagonally extending straps 27 and 27a and oppositely disposed with respect thereto is a pair o1 straps one of which is indicated at 28. These straps at their lower ends are secured to suitable plates 29 which are in turn connected to the member 241 just above the plate 12. The ends'o't the straps 27 and 27a and the oppositely.disposed straps 28 and 28a are so arranged that the connection with the plate 29 may be removed so that the whole structure which has just been described, to-wit, the members 25, 25a, 27 and 27'L1 and the pair of oppositely disposed straps 28 and 28 may move pivotally about the point 26. This construction is purposeful in that it permits l the entireferecting device tovv be moved downwardly through the tower afterthe complete erection thereof, which `would otherwise notbe-possible due to the yfact thatthe member 25.atthe end of theiiiember 2llefrtends beyond the sides of they tower. At the ends of the=membersand .2571 there are pulleys 30y kandailand there is a-pulley t32-which is and if desired this cable after passing overV the `'pulley 32 may pass: through a'suitf-ible opening, into the tubular member 24 and down tothebottoml of the towerto the hoisting apparatus. This constriiction` permits the hoisting Acable :to be centrallyarranged withinthe tower and thus-Aout of the way., l
And inasmuch as theendV of thehoisting eableis in certain positions beyond the sidesof the tower, thereisprovided a block and tackle arrangement for .pulling in they This comprises a pulley 34 and an opposite pulley 35 which pulleys are respectively attachedto the end lowerend of the cable.
of the cable 33 and to the member 2i.l t
lt twill be seen that :due to the mounting ofthe member 24 the whole hoisting apparatus which has just been described is located so that the hoisting end of the cable 33 may be moved so as to position the various parts of the tower which is being erected.
At the lower portionof the erecting device as for instance upon the oppositely disposed plates 18 there are secured p-ulleys 36.
and 37.` The rope or cablewhichpasses over these pulleys is passed aroundy other pulleys such as indicated at 38 and 39 which pulleys and cable are for the purpose of moving the erecting device upward within the sections of the tower which have completed.
In the illustration of Fig. 1 we may assume that the erecting 'apparatus has'just been elevated upon a completed section of the tower, and in this position the next secbeen . tion of the tower Vmay be erected by the workmen from the platforms 9 and 14, utilizing the hoisting apparatus before described to elevate the sections of the tower which are to be placed. When the additional tower section is'completed, as represented by the dotted lines in Figs. 1 and 2, the pulleysf38 and 39 will .be attached to the upper part of the tower section which has been completed, v andl by this `means the entire erecting device may beraised as a unit. The raising operation continues until the dogs 2l are in position to engage above the upper side membersof the tower section which has been erected in a similar position to that Shown in Fig. 2. During this opera-tion the movement of the erecting device is guided which vhave through the engagement between the guide members 16, 17, 16 andla on the erecting device and the; guides 3 and l on the tower.-
Vlien the erecting device is elevated as kdescribed the platforms 9 and 14 and the hoisting mechanism associated; with t-he erecting device are all abovethe completed pordisengaged from the plates 2,9 whichV per- Y mits these members together with thel meinbers25A and`25a to assume the positionshown in dotted lines in Fig. 1 in which position the entire erecting device may be lowered within the tower, to the lower endlof the tower and there disassembled and removed.
While inthe present construction vas described the guide members such vas those indicatedat 16,17, 16a and'1?a have the erecting device cooperated with the guide mem-` bers such as S anellil carried by the tower, it, will be understood that this particular construction is not essential, as the erecting device may 'be guided by engagement withl other portions of the tower than that specifically pointed out.
Having described my invention, I claim:
1. The combination with a skeleton tower adapted to be built'up in superposed sections, said sections having alined vertical guide members forming a guideway, of an erection device comprising a rigid frame slidably mounted in the vertical guideway of the tower and provided with a platform,
said erection device having 'hoisting means above said platform, and means for securing said erection device the tower. y
2. The combination with a skeleton tower adapted *to be built up in superposed sections, Asaid sections having secured to opposite sides upon the interior thereof, alined vertical guide members forming guideways, of an erection device comprising a rigid frame mounted for vertical movement within the tower and having on opposite sides thereof guide kmembers engagingjthe guideways, said frame having aplatform mounted upon the upper portion thereof and said erection device having hoisting means above the platform, and means for raising and lowering the frame in the tower and for securing the same in adjusted in adjusted positions on positions. f f
3. An erecting device adapted yfor usekin erecting a tower, comprising a frame having iis .y
a transversely extending central member, de-
pending guide members from the central members, braces connecting the lower ends of the said guide members with the said central member, converging diagonal members extending above the central member, means for retaining the upper ends ot' said converging members and a platform supported from the said converging members.
4. An erecting device adapted for use in erecting a tower, comprising a frame having a transversely extending central member, depending guide members from the central members, braces connecting the lower ends ot the said guide members with the said central member, converging diagonal members extending` above the central member, means for retaining the upper ends of said converging members, a platform supported from the said converging members, a tubular member extending centrally with respect to the frame and rotatably supported by said transverse member at the central portion of the frame, means at the upper ends of the converging members for retaining the said tubular member and a`hoisting member mounted upon the said tubular member.
5. An erecting device adapted for use in erecting a tower, comprising a frame having a transversely extending central member, depending guide members from the central member, braces connecting the lower ends of the said guide members with the said central member, converging members extending above the cent-ral member, means for retaining the upper ends of said diagonal members and a platform supported from the said converging members, a tubular member extending centrally with respect to the frame and supported by the transverse member at the central portion of the frame and supported for rotation, means atthe upper ends ot' the converging members for supporting the said tubular member, and transversely extending member pivotally mounted upon the upper end of said tubular member, tie rod members connecting the opposite ends of the said transversely extending member to the tubular member, the said tie rods being detachable, whereby the transversely extending member may be turned about its pivot7 pulleys mounted at the opposite ends of the transversely extending member and a pulley mounted upon the tubular member and adjacent thereto and a hoisting rope extending around said pulleys and through the tubular member.
In testimony whereof, I hereunto am); my
signature.
JOSEPH H. MOSEL.
US452374A 1921-03-14 1921-03-14 Tower erection derrick Expired - Lifetime US1551837A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US452374A US1551837A (en) 1921-03-14 1921-03-14 Tower erection derrick

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US452374A US1551837A (en) 1921-03-14 1921-03-14 Tower erection derrick

Publications (1)

Publication Number Publication Date
US1551837A true US1551837A (en) 1925-09-01

Family

ID=23796214

Family Applications (1)

Application Number Title Priority Date Filing Date
US452374A Expired - Lifetime US1551837A (en) 1921-03-14 1921-03-14 Tower erection derrick

Country Status (1)

Country Link
US (1) US1551837A (en)

Similar Documents

Publication Publication Date Title
US3483933A (en) Oil derrick erection and support system
US2781108A (en) Self-erecting derrick
US4134237A (en) Modular section mast
US2168837A (en) Oil well rig
US2742260A (en) Well derrick
US3494593A (en) Portable mast
US3977531A (en) Stiff-leg crane
US2857026A (en) Device for erecting elevator towers
US4530648A (en) Wall climbing form hoist
US2583072A (en) Derrick
US1834652A (en) Mast hoist
US1551837A (en) Tower erection derrick
DE3342265A1 (en) DISASSEMBLY DEVICE FOR A TOWER CRANE BOOM
US2031549A (en) Crane
US2754012A (en) Apparatus for erecting elevated structures
US1853086A (en) Tower for elevating construction materials
US2283049A (en) Derrick
US1853085A (en) Tower for elevating construction materials
US3367448A (en) Mobile elevator
US2503604A (en) Mast structure
US2221067A (en) Structural steel derrick
US2225561A (en) Derrick
US3181649A (en) Portable tower construction
US3416267A (en) Collapsible derrick for drilling
US3138828A (en) Erecting arrangement for portable building