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Publication numberUS3627079 A
Publication typeGrant
Publication dateDec 14, 1971
Filing dateOct 31, 1969
Priority dateOct 31, 1969
Publication numberUS 3627079 A, US 3627079A, US-A-3627079, US3627079 A, US3627079A
InventorsSwend F L Nielsen, Guido K Wegner
Original AssigneeNorse Dev Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Elevator system for mine shaft
US 3627079 A
Images(6)
Previous page
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Description  (OCR text may contain errors)

United States Patent 1111 3,627,079

[72] Inventors Swend F. L. Nielsen 3,178,048 4/1965 Bergman 187/12 San Mateo; 3,204,721 9/1965 Park 1. 182/178 Guido K. Wegner, Paclllce, both of Calif. 3,298,462 1/1967 Morris 182/178 [21] Appl. No. 872,898 3.5l7,775 6/1970 Meyer 187/95 1 Filed Oct-31.1969 FORElGN PATENTS 2; T m 2 7 C I 1,443,262 6/1966 France 187/6 1 1 1 974,317 11/1960 Germany 187/12 1,294,078 4/1969 Germany 1. 254/173 Primary Examiner- Harvey C. Hornsby [54] ELEVATOR SYSTEM FOR MINE SHAFT Almmey-Owen, Wickersham & Erickson 9 Claims, 23 Drawing Figs.

An under ground elevator system for mine per- 187/20 187/27 187/94 187/95 182/178 sonnel comprised of support mast formed from a plurality of I 254/173 prefabricated structural sections that are connected in an end- {251 112150;6515;:3113311111111::iijjijijij: "1: 1231 10792, and side of shaft. The mast includes an emergency escape ladder enclosed 951254/173; 182/178 by removable wire mesh and a cab movable along and guided [56] References Cited by one side of the mast, the cab being mounted thereon by means that can be adjusted to maintain it level despite the UNITED STATES PATENTS degree of mast incline. The cab is driven by cable hoist means Pratt mounted at the top of the mast and ingludes an ove speed- 1,891 81181111611 catching means and a slip..sensing afety mean5 2,232,890 2/1941 Stillwagon 187/12 2,463,215 3/1949 Strachan 187/95 5 T: is its 28 s s 25 k 5 is 2 e 42 5 9 k; 0 3 s 1 a i s ,9 if P 1 i s Patented Dec. 14, 1971 3,627,079

6 Sheets-Sheet 1 FIG 4 Patented Dec. 14, 1971 3,627,079

6 Sheets-Sheet 2 q u 14 64a 6 FIG- 5 INVENTORS F| 7 swam) F. L. NIELSEN BY GUIDO K. WEGNER ATTORNEYS Patented Dec. 14, 1971 3,627,079

6 Sheets-Sheet 3 FIGJO 42 FIG 9 H FIG I sws flo F' L l z l l eu GUIDO K. w GNER ATTORN EYs' Patented Dec. 14, 1971 31%;? 7 W? 6 Sheets-Sheet 5 HNVENTORS SWEND F. L. NNELSEN M1 BY sumo K. WEGNER F fl ATTORNEYS Patented Dec. 14, 1971 3,627,07

6 Sheets-Sheet 6 POWER CONTROL CIRCUIT I |9o I82 .1) I84 Q I72 I70 I II I I [I I64 I66 :1 i I I l 3 I I I58 I I62 I I60 Q I56 FIG-J9 FIG-20 SWEND F.L. NIELSEN BY sumo K. WEGNER ATTORNEYS ELEVATOR SYSTEM FOR MINE SHAFT This invention relates to an improved elevator or vertical transportation system for installation in underground mine shafts and die like.

Timber beam construction has long been used for mine shafts and the like to provide the means to reinforce the shaft and support an elevator cage and its counterweight. Generally, such construction comprised a double compartment arrangement as required by mine safety standards, with one compartment housing the elevator or cage and the other compartment including provisions for an escape ladder in the event of a power failure. Such timber type construction had several disadvantages and created certain problems, because it was complicated, expensive and time consuming to install, as well as being vulnerable to fire and the other limitations inherent with wood. A general object of the present invention is to overcome these disadvantages while solving the problem of providing a mine hoist system having the required safety facilities.

Another object of the present invention is to provide a mine hoist system that can be erected quickly and easily with a minimum requirement for labor and equipment and, more particularly, one that can beprefabricated in sections and then assembled later within a shaft with the sections fixed to the walls of the shaft. The invention also provides a system wherein the mast sections themselves as well as other equipment for the hoisting system can be easily dismantled and moved elsewhere or modified and increased in size.

Still another object of the present invention is to provide a mine hoist system utilizing prefabricated metal mast sections in a mine shaft having strong, structural connector means capable of being anchored firmly in irregular shaft walls. The aforesaid connector means compensate for irregular surfaces of the shaft walls and thereby maintain longitudinal alignment of the mast or tower sections with sufficient accuracy to enable them to serve as guide rails for a vertically movable cage frame and a cab attached thereto.

Most underground mine shafts penetrate the ground at an angle close to a vertical line, but this angle may vary over a considerable range for different shafts. Since the mast within the shaft necessarily is oriented at the same angle as the shaft and the cab is movable on and guided by the mast, some means must be provided for attaching the cab to the mast so that the cab floor will be level. Another object of the present invention is to provide an adjustable connection between the cab and the mast that will allow the cab to assume a normal position as it moves up and down.

Yet another object of the present invention is to provide a slip sensing means on the cable drive system for the cab that will automatically arrest the cab if any slippage occurs when the cab is supposed to be stopped at any point on the mast.

The aforesaid and other objects are accomplished by a prefabricated tower or mast comprised of interconnectable sections that can be lowered into an underground shaft and then fastened together and also to a wall of the shaft to form a supporting structure for a movable cab. Each section in addition to providing the required structural strength includes an internal ladder and protective walls. When connected, the mast sections provide a complete, protected escape means from any level of the shaft. Structural members of the sections form rails to which are movably attached a cage frame that supports a personnel cab or freight platform. The cage frame is controlled by cables connected to a hoisting mechanism at the top of the mast and to a counterweight located at one side of the mast. The cab is operable by conventional controls through a control cable extending from the cab to the hoist mechanism at the upper end of the mast. The mast is easily installed and set up for operation and when necessary, it can be dismantled and moved to another location with a relatively small expenditure of time and labor.

Other objects, advantages and features of the present invention will become apparent from the following detailed description which is presented with the accompanying drawing, in which:

FIG. 1 is a view in front elevation showing an assembled mine shaft hoist system embodying the principles of the present invention;

FIG. 2 is a view in side elevation of the mine hoist system shown in FIG. 1;

FIG. 3 is an enlarged fragmentary view in perspective showing the power drive system at the upper end of the hoist system;

FIG. d is an enlarged fragmentary view in elevation showing the lower end of the mine hoist system according to the present invention;

FIG. 5 is a view in side elevation of one mast section for the mine hoist system shown in FIGS. I and 2;

FIG. 6 is a view in front elevation of the mast section shown in FIG. 11;

FIG. 7 is a top view of the mast section shown in FIG. 5;

FIG. 8 is an enlarged fragmentary plan view showing one comer of a mast section;

FIG. 9 is a view in front elevation of the cage frame for the mine hoist system according to the present invention;

FIG. I0 is a view in side elevation and in section taken along the line 10-40 of FIG. 9;

FIG. 11 is an enlarged fragmentary view in section taken along the line Ill-ll of FIG. 9;

FIG. Ila is a view in section taken along the line Ilia-41: of FIG. I ll;

FIG. 12 is an enlarged fragmentary view in section taken along the line 12-12 of FIG. 9;

FIG. 12a is a view in section taken along the line l2a-l2a of FIG. 12;

FIG. 13 is an enlarged view in section taken along the line 13-13 of FIG. 9;

FIG. 13a is a view in section taken along the line Ilia-13a of FIG. 13;

FIG. 141 is a greatly enlarged view in side elevation showing a portion of a mast section with the cab attached thereto;

FIG. 15 is a further enlarged fragmentary view in elevation showing one connection of the cab on the cage frame;

FIG. 16 is an enlarged plan view showing the connectors for securing the mast sections to a shaft wall;

FIG. 17 is a view along line I7-l7 ofFIG. 16;

FIG. 18 is a view in elevation and in section taken along line I8-ll8 of FIG. 17;

FIG. I9 is an enlarged view in side elevation showing the slip sensing device on the power control section;

FIG. 20 is a view in front elevation and partially in section of the device shown in FIG. 19.

GENERAL DESCRIPTION Referring to the drawing, FIG. 1 and 2 :show a mine hoist assembly 20 embodying the principles of the present invention as it appears when installed in a typical mine shaft 22 that extends downwardly from a surface opening and interconnects mine drifts 241 at various levels. The mine shaft may be formed by any conventional excavation method and has generally a rectangular cross section. As shown, the shaft enters the ground at an angle to the vertical, as is common in shaft mining, but the present mine hoist is adaptable for installation in shafts inclined as much as 40 to the horizontal. Generally, the mine hoist assembly comprises a plurality of prefabricated mast or tower sections 26 that interconnect together in an end-to-end arrangement and are fixed by anchoring means 28 to one wall of the shaft. The upper mast section 26a forms a support platform 30 for a power drive unit which, as shown in FIG. 3, includes an electric motor 32 connected through a suitable transmission and control unit 34 to a winch or traction sheave 36 to which a series of lifting cables 38 are attached. The lower mast section 26b is supported at the bottom of the shaft in a body of concrete 40, unless the surrounding rock material is sufficiently stable to serve the same purpose. The intermediate mast sections 26 between the top and bottom sections 26a and 26b are all structurally identical and are interconnected to form the complete tower or mast of the desired height. 7

Connected to and movable up and down the mast is a cage frame 42 to which are attached the lifting cables 38 from one side of the traction sheave 36. As shown in FIG. 2, the same cables from the other side of the traction sheave extend down the shaft and are connected to the upper end of a counterweight 44. For hoists over 300 feet high, a series of compensating ropes 46 are fixed to the lower end of the counterweight 44 and extend downwardly and around a series of compensating rope sheaves 48 supported in the base mast section 2612, as shown in FIG. 4. From the latter sheaves these compensating ropes extend upwardly and are fixed to the lower end of the cage frame.

Attached to the cage frame 42 is a cab 50 for carrying personnel which is adjustable in its position so that it can remain level despite the slope or incline of the mast sections 26. The cab contains operating controls which preferably are similar to those in automatic passenger elevators thereby making the hoist operable by any personnel and eliminating the need for a special hoist operator. Details of such control systems are available in the prior art and will not be described herein since they do not comprise part of the present invention. A control cable 52 from the cab controls extends through a control cable trolley 54 that is movably supported in a trolley rail 56 fixed adjacent to one side of the connect mast sections 26. This trolley rail extends from approximately the midheight of the mast to near its base. From the trolley the control cable extends upwardly to the power drive unit. Thus, as the cab moves up and down on the mast, the control cable is kept straight and under tension and thus free from entanglement with surrounding structure.

THE MAST SECTIONS 26 As shown in FIGS. -7, each mast section 26 is comprised of pairs of upright front and rear structural members 58 and 60 which are parallel, spaced apart and connected by suitable cross beam members 62 and 63 at their upper and lower ends. Preferably these upright members have a square tubular cross section and at their upper and lower ends each has a transverse plate 64 or 64a. The plates 64 at the top ends are each provided with a diagonal slot 66 while the plates 64a at their bottom ends have similarly oriented vertical aligner plates 68 which are fixed so that they extend below the ends of the upright members. Thus, when one mast section 26 is placed on top of another section the aligner plates 68 at the lower ends of the upper section fit within the slots 66 of the lower section and maintain the two connected sections 26 and their upright members in perfect alignment. The cross beam members 62 at the upper and lower ends of each section, as shown in FIG. 8, have horizontal flange portions 70 that are flush with the transverse end plates 64 and 64a of the upright members. These flange portions have bolt holes 72 at predetermined lo cations near their ends which automatically align and match with similar holes on adjoining sections when the guide plates 68 are inserted within the slots 66 as described. Bolts (not shown) through these holes 72 are then easily inserted and tightened to hold the adjoining mast sections firmly together.

Additional diagonal reinforcing members 74 are used to interconnect the upright members 58 and 60 and strengthen each mast section. Extending from the lower end to the top end of each section, preferably at a slight angle to the vertical, is a ladder 76. On the sides of each mast section between the two front'upright members and between the front and rear upright members on both sides are panels 78 of a suitable wire mesh material such as expanded metal mesh. This provides a protective shield around the mast for anyone using the emergency ladder. The wire mesh panels are secured by suitable fasteners and are thus easily removable so that access to the ladder can be readily accomplished at any point along the mast.

As shown in the cross-sectional view of FIG. 8, the front upright members 58 of each mast section 26 are larger in cross section than the rear upright members 60 and they extend outwardly from the sides of the interconnecting frame members 62 and 63. Thus, on each front upright member there are front and rear parallel surfaces 80 and 82 and a planar outer side surface 84, all of which extend its full length. These three surfaces thus provide guide means forretaining the cage frame 42 on the mast as it moves up and down.

THE MAST-ANCHORING SYSTEM The mast sections are attached to one wall of the shaft by means of rockbolts 136. While various types of rockbolts may be used depending on the nature of the material surrounding the shaft, a preferred structural arrangement for anchoring the mast sections using rockbolts is shown in FIGS. 16 to 18. Generally, it comprises a structural cross beam 138 having a box type cross section to which are attached a pair of retaining plates 140. The latter are hook-shaped'in plan form and fit around the rear upright members 60 of a mast section 26, the upright members fitting into the pockets 142 of the retainer plates 140. Spaced outwardly from the retaining plates on the beam are openings 144 through which the rockbolts extend. When the mast is erected, the rockbolts 136 are first set in drilled holes in the shaft wall at the proper spacing. The beam 138 is then placed in position with the retaining plates hooked around the mast members 60 and the rockbolts extending through openings 144 in the beam. Timber blocks and wedges 146 are placed between the beam 136 and the shaft wall 148 to take up excess space. Anchor nuts 150 which bear against channel-shaped washer plates 152 are attached to the end of each rockbolt. With the mast and beam adjusted to the proper position using the shims 146 where necessary, the anchor nuts are then tightened to secure the mast sections to the shaft wall.

THE CAGE FRAME 42 The cage frame 42, as shown in FIGS. 9 to 13, is fabricated from structural steel members in a conventional manner and comprises essentially a pair of parallel, spaced apart side members 86 interconnected by suitable supporting cross members 88. Spaced downwardly from the top end of each side member is an upper connector 90 for holding the cage frame on a front mast member 58. As shown in FIGS. 11 and 11a, these upper connectors are comprised of a pair of front and side rollers 92 and 94 which are rotatably mounted on the cage frame so that their axes are at right angles to each other and their surfaces will engage the front and side surfaces 80 and 84 of a front mast member 58. A pair of third or rear rollers 96 which are narrower than the front roller 92, are spaced from it so as to engage the rear surface 82 of the front mast member. Each upper connector thus surrounds a front mast member on three sides and thereby holds the cage frame on the mast. Spaced upwardly from the lower end of the cage frame are a pair of lower connectors 98 as shown in detail in FIGS. 12 and 124. Each of these lower connectors comprises a pair of rollers 100 and 102 which are mounted on the cage frame with their axes at right angles to each other, thereby positioning the rollers so that they engage the front and side surfaces 80 and 84 of the front mast members 58. Another pair of rollers 104 as shown in FIGS. 13 and 13a are preferably mounted on a bottom cross beam 106 at the lower end of the cage frame 42 and are positioned to engage the front surface of the front mast members. The cross beam 106 is attached to but spaced from a similar cross beam 108 and mounted transversely between these two beams are five pins or bolts 110 to which the ends of the compensating ropes 46 are attached. Fixed to the opposite ends of the cross beams 108 and 110 are a pair of circular plates 112 that serve as contact pads for engaging a pair of bumper springs 114. The latter springs are mounted at the bottom end of the mast section as shown in FIG. 4.

THE CAB 50 The cab is essentially a fabricated steel frame 116 mounted on a platform 118 to which walls 120 of sheet metal and/or heavy wire mesh material are attached. The walls are held in place by any suitable fasteners that allow them to be easily removable when desired. Both a vertical sliding door on one side and horizontal swinging doors on the other side may be provided as well as an escape hatch in the ceiling on the cab. in accordance with an important feature of the invention the cab is attached to the cage frame 42 by means of removable pins and a linkage that allows the cab to remain level despite an angle of incline on the mast. As shown in FIGS. 14 and 15, the cab frame 116 is reinforced at one end of a bottom frame member 11% by a plate 126 which is bored to receive a lower pin 12%. A corresponding bottom frame member on the other side of the cab is similarly bored to receive another lower pin. These two lower pins 128 are axially aligned and extend through similarly aligned bore holes located near the lower end of the outer longitudinal members 86 of the cage frame. At the top of the cab are a pair of top frame members 130 that are provided with axially aligned bores for receiving a pair of pins (not shown) each of which also extends through one end of a link 132. The other ends of both of these links are connected by a pair of pins 134 that extend through aligned bores near the upper end of the cage frame. The holes near opposite ends of the links 132 are spaced apart so that the cab will assume a normally level position when the links are attached to the cage frame. For different angles of the shaft and thus the mast installed therein, the distance between the holes for the pivot pins in the links 132 can be varied so that the cab will be level. Links with a series of alternate holes can be provided to provide for cab level adjustment.

THE SLIP-SENSING DEVICE 154 As part of the power drive and control system a slip-sensing means 154 is provided on the upper mast section 260 which detects any slippage of the lifting cables 38 on the traction sheave 36. As shown in FIGS; 19 and 20, this device is mounted on a platfonn 156 adjacent to the traction wheel and comprises an arm 158 which is pivotally connected at its lower end to a bracket 160 fixed to the platform. Extending upwardly from the bracket and in line with the arm is a stationary member 1162 to which is fixed a bolt 164 that extends horizontally through the arms. A coil spring 166 surrounds the bolt with one end of the spring being retained by a nut I68 on the end of the bolt. The opposite end of the spring bears against the arm, thereby urging it in one direction toward the traction wheel. At the upper end of the pivotal arm is a bracket 170 supporting a pin 172 to which is pivotally connected a pair of links 1174. At theirlower ends the links rotatably support a shaft 176 to which is attached a lower contact roller 178, and at their upper ends these links 174 support another shaft 180 to which is fixed an upper roller 182. The upper roller normally turns with its shaft when it is free to do so, but if the roller is restrained while the shaft 180 is turned, the roller 182 will tend to move axially on the shaft. The lower roller 178 is positioned to bear directly against one lifting cable 38 extending from the traction wheel while the upper roller 182 is positioned to engage the traction wheel itself. Both of the shafts 176 and 1180 are provided with small sprocket wheels 184 which are connected by a small continuous chain 186 so that the rotation of the two rollers is normally .the same, as when there is no slippage of the cable on the traction wheel. The upper roller has an annular groove 188 near one end within which rides the arm 190 of a limit switch 192. The latter, which may be any suitable type that is commercially available, is connected in the power control circuit of the hoist drive.

The operation of theslip sensing cutoff device should be apparent from the foregoing description. lf slippage of the lifting cable 38 contacting the lower roller 178 occurs, the lower roller willrotate faster than the upper roller 182. Since the.

two roller shafts 176 and 1180 are connected by a direct chain drive 186 the upper shaft 180 will be driven by the lower roller 178 and its shaft 176 and thus the upper shaft will rotate faster than the upper roller. This causes the upper roller M2 to move axially on its shaft and thereby actuates the limit switch arm 190 that rides in the groove of the upper roller.

As stated previously the control system for the cab or elevator may be of any suitable type that is commercially available. In addition, the system may include the usual safety provisions such as a suitable overspeed'catching device. From the foregoing it should be apparent that the present invention provides a unique mine hoist that may be erected with a minimum of labor in a relatively short time. The only on site construction jobs are the assembly of the mast sections and their attachment to a shaft wall. Yet, the system has the versatility and safety features of much more complicated and expensive permanent mine elevator installations.

To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein are purely illustrative and are not intendedto be in any sense limiting.

We claim:

ll. A combined elevator and escape passage for installing in .a mine shaft comprising:

a plurality of prefabricated mast sections each having parallel spaced apart front and rear longitudinal members connected by crossmembers;

means on the ends of said longitudinal members for connecting said mast sections together in longitudinal alignment;

means for securing said rear longitudinal members to one wall of the mine shaft;

cage frame means movably mounted on said front longitudinal members; I

a cab extending outwardly from said. cage frame and means for adjustably connecting said cab to said cage frame for keeping it in a level position for varied angular positions of the mast sections;

each mast section including a ladder located within the cross-sectional area defined by said longitudinal members, and wall means attached to said longitudinal members to provide a protected escape passage; and

power control means mounted on a top mast section including lifting cables connected to said cage frame means for moving it up and down on said connected front longitudinal members of said mast sections.

2. The elevator system as described in claim 1 wherein said front longitudinal members on each mast section have a flat sided cross section, aligner means fixed in the ends of said longitudinal members for maintaining the longitudinal members of adjoining mast sections in alignment.

3. The elevator system as described in claim ll wherein means for connecting said mast sections together includes aligner means comprising transverse plates fixed to the ends of said longitudinal members, an edge mounted plate fixed to each said transverse plate at one end of each mast section, and slots in said plates located at the other end of said mast section; and bolt means through said cross members of adjoining mast sections adjacent said longitudinal members.

4. The elevator system as described in claim I wherein said adjustable means comprises a pair of fixed pivotal connections between the lower end of said cab and the cage frame and a pair of links each pivotally connected at one end to said cage frame and at the other end to the upper end of said cab.

5. The elevator system as described in claim 11 wherein said means for securing said rear longitudinal] members to the shaft wall comprises a transverse beam, hook: means on said beam for engaging said rear longitudinal members, a pair of spaced apart rock bolts adapted to be embedded in the shaft wall, and means for securing the ends of said rock bolts to said transverse beam.

6. The elevator system as described in claim 1 wherein said power control means on said upper mast section includes a traction wheel, motor means and means drivingly connecting said motor means to said traction wheel, a counterweight, cable means extending around said traction wheel and connected at opposite ends to said cage frame and to said counterweight.

7. The elevator system as described in claim 6 wherein slipsensing means adjacent said power control means for sensing any relative slippage of cables on said traction wheel,

8. The elevator system as described in claim 7 wherein said slip-sensing means comprises means contacting said traction wheel and a cable thereon and responsive to a differential movement between them for deactivating said power control means.

9. An elevator system for installation in a mine shaft comprising:

a plurality of prefabricated mast sections each having parallel spaced apart front and rear longitudinal members connected by cross members;

means on the ends of said longitudinal members for connecting said mast sections together in longitudinal alignment;

means for securing said rear longitudinal members to one wall ofthe mine shaft;

cage frame means movably mounted on said front longitudinal members;

a cab attached to said cage means;

power control means mounted on a top mast section including a traction wheel, motor means and means drivingly connecting said motor means to said traction wheel, a counterweight and lifting cables extending around said traction wheel and connected at opposite ends to said cage frame and to said counterweight for moving the cage frame up and down on said connected front longitudinal members of said mast sections;

and slip-sensing means adjacent said power control means for sensing any relative slippage of cables on said traction wheel, said slip-sensing means comprising a pair of first and second rollers mounted on a pair of spaced apart first and second shafts, respectively, means for supporting said shafts so that said first roller engages said traction wheel and said second roller engages a cable that extends around said traction wheel, chain means drivingly connecting said shafts, means on said first shaft for causing axial movement of said first roller whenever its rate of rotation is less than that of said shaft, and means on said first roller for actuating a switch to stop said power control means when said first roller is caused to move axially.

lOlOH 0l60

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3880258 *Dec 27, 1971Apr 29, 1975Rompa Jozef Johannes TheresiaLift for installation against a substantially vertical wall
US7093457 *Jan 23, 2004Aug 22, 2006Metso Minerals Industries, Inc.Annular cooler pallet construction
US8021098Jun 19, 2008Sep 20, 2011J.S. Redpath LimitedPortable raise climbing system
US8172499Aug 30, 2011May 8, 2012J.S. Redpath LimitedPortable raise climbing system
US8297413 *Jun 21, 2007Oct 30, 2012Mitsubishi Electric CorporationSafety device for elevator and rope slip detection method using drive sheave acceleration
US20100276231 *Apr 27, 2010Nov 4, 2010William Mark AdamsLifting apparatus
US20100300813 *Jun 21, 2007Dec 2, 2010Mitsubishi Electric CorporatioinSafety device for elevator and rope slip detection method
US20120048654 *May 20, 2010Mar 1, 2012Consep Pty LimitedSelf-Climbing Material Hoist
WO2008154732A1 *Jun 19, 2008Dec 24, 2008Randy E GrenonPortable raise climbing system
Classifications
U.S. Classification187/406, 182/178.1, 254/270, 187/242, 187/262, 187/900, 187/410
International ClassificationB66B9/06
Cooperative ClassificationB66B9/06, Y10S187/90
European ClassificationB66B9/06