US3191759A

US3191759A - Suspension assemblies for flexible belt conveyors

Info

Publication number: US3191759A
Application number: US185013A
Authority: US
Inventors: Presti Roy F Lo
Original assignee: Goodman Manufacturing Co LP
Current assignee: Goodman Manufacturing Co LP
Priority date: 1962-04-04
Filing date: 1962-04-04
Publication date: 1965-06-29
Anticipated expiration: 1982-06-29
Also published as: GB1040951A

Description

June 29, 1965 R. F. 1.0 PRES 3,191,759

SUSPENSION ASSEMBLIES FOR FLEXIBLE BELT CONVEYORS Filed April 4, 1962 2 Sheets-Sheet 1' k 'IIIIIIIIIIIIIII $2? Q {Pr/Ill N N m N Q N IN VEN TOR.

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J n 2 1965 R. F. LO PRESTI SUSPENSION ASSEMBLIES FOR FLEXIBLE BELT CONVEYORS 2 Sheeis-Sheet 2 Filed April 4, 1962 J nu mww n n INVENTOR /?ay/? /4 pm; 4, BY 710% ffdr/zr United States Patent 3,191,759 SUSPENSIGN ASSEMBLIES FUR FLEXIBLE BELT CQNVEYORS Roy F. Lo Presti, Chicago, 111., assignor to Goodman Manufacturing Company, Chicago, 111., a corporation of Illinois Filed Apr. 4, 1962, Ser. No. 185,013 10 Claims. (Cl. 198192) 0 This invention relates to wire rope conveyors, and particularly to an assembly for suspending such conveyors from an elevated support location, such as a mine roof, although the invention may be utilized equally well with Wood or metal suspending frameworks.

Accordingly, a primary object of the invention is to provide a suspension assembly which enables a wire rope sideframe to be quickly and accurately suspended from an elevated support location.

Another object is to provide such a suspension assembly having infinite adjustment.

Yet another object is to provide a conveyor suspension assembly anchorable to the roof which does not require greater exactness in installation than what is employed in present practice.

Yet a further object is to provide a suspension assembly in which the length of an elongated, downwardly depending suspending member which is secured to the Wire rope sideframe may be easily and quickly adjusted after installation, and even during use, without disturbing either the roof bolt to which it is secured or other rigidly installed portions of the suspension assembly. I

A- iurther object is to provide a suspension assembly for a wire rope sideframe which easily accommodates longitudinal shifting of the wire ropes and does not exert a detraining efiect on the conveyor belt at any time.

Yet a further object is to provide wire rope suspendmg means which may be combined with structure for maintaining a required rope gauge, such as a spreader bar, thereby eliminating a set of rope clamps which would be required if the suspending means and gauge maintainmg structure were separate units.

Other objects and advantages of the invention will become apparent from the following description. Y

The invention is illustrated more or less diagrammatically in the accompanying figures, in which:

FIGURE 1 is a perspective view taken substantially along the line 1-1 of FIGURE 4 showing the preferred embodiment of the invention;

FIGURES 2 and 3 are sectional views of the preferred term of the invention illustrating variant forms of lockmg means;

FIGURE 4 is a top plan view, partly schematic, illustrating the preferred embodiment of the invention;

FlGURE 5 is a top plan view illustrating the versatility of the invention;

FIGURE 6 is a perspective view of a second embodiment of the invention;

:FIGURE 7 is a perspective view of a third embodiment of the invention;

FIGURE 8 is a perspective view of a fourth embodiment of the invention; and

FIGURE 9 is a perspective view of a fifth embodiment of the invention.

Like reference numerals will be used to refer to like parts throughout the following description of the figures.

A suspension assembly is indicated generally at 10 in FIGURE 1. The assembly includes a plate member 5 having a generally horizontal, generally rectangular shaped portion 11 which terminates at one edge in a downwardly extending portion 12. The lower end of downwardly extending portion 12 terminates in an up- 3,191,?59 Patented June 29, 1965 turned flange 13. In this instance the flange diverges outwardly upwardly slightly from the generally vertical portion 12, but it will be understood that within the scope of the invention the included angle between the bottom of portion 12 and flange 13 may vary. It is contemplated, for example, that the surfaces might advantageously be generally parallel to one another.

The fiat, upper portion 11 is apertured to receive a roof bolt 14-. The head of the roof bolt holds the flat plate 11, and thus the balance of the suspension assembly, tightly against the mine roof as seen for example in FIGURE 6.

A hanger assembly is indicated generally at 15. The hanger assembly includes a hanger 16 which essentially is a short strap. The hanger terminates at its upper end in a downturned lip 17 which is received between flange 13 and vertical plate portion 12. A keyhole slot 18 is formed in the lower end of hanger 16. The keyhole slot is of a size sufiicient to receive and lock a chain 19 in place. The lowermost end of the chain terminates at a releasable closure member, such as cold-shut 20, which in turn is secured to a rope clamp 21 as by pivot pin 22. Although a special attachment for securing the lowermost end of chain 19 to the rope clamp 21 has been shown, it will be understood that within the scope of the invention the chain could be secured directly to the rope clamp in any convenient manner.

A tightening screw is indicated at 25. The tightening screw is threaded through an aperture in hanger 16 and abuts the exterior surface of flange 13.

The lower end of lip 17 may advantageously terminate in an inwardly directed tip 26. When the tightening screw 25' is rotated clockwise, a tight frictional engagement between the abutting inner surface of lip 17 and inner surface of flange 13 is created. Flange 13 may advantageously be a softer metal than the tightening screw 25, so that the screw actually digs into the flange slightly, thereby being positively seated. Tip 26 is curved inwardly complementarily to the inner curvature of flange 13 to thereby enable the tip'to conform and bottom therein. 7

In this instance the chain 19 terminates in a separate rope clamp 21 which is spaced from a similar rope clamp 27 carried by the end of spreader means 28. For pur-' pose of illustration the spreader means has been illustrated as a downwardly dished spreader bar, analogous to the spreader bars shown in Newton et al. Patent No. 2,911,- 090. It will be understood that within the scope of the invention any suitable spreader means may be used to maintain a desired wire rope gauge. The member 23 could for example be part of a cradled idler assembly.

In FIGURE 2, a plurality of apertures, one of which is indicated 29, has been formed along the lower edge of vertical portion 12. A complementary projection 30 has been formed on the terminal edge of lip 17a, in place of tip 26, the projection 36 being of a size easily received in any one of apertures 29.

Although in this instance the plate portion 12 has been apertured and the projection formed on lip 17a, it will be understood that within the scope of the invention the location of these two parts may be reversed. With this construction the tightening screw 25 is eliminated since it would tend to pull the projection 31) out of aperture 29 when tightened. The weight of the conveyor maintains the parts in the position of FIGURE 2.

In FIGURE 3 the bight portion of plate 11) has had for ed therein a plurality of apertures 31, one or more.

of which receive one or more projections 32 formed along the terminal edge of lip 17!). The downwardly directed weight of the conveyor will prevent the lip 17]; from being jostled out of aperture 31. It may be desirable to utilize the tightening screw 25 with the FIGURE 3 arrangement. If used, the screw is merely anchoring or locking means.

The versatility of the suspension assembly is illustrated in FIGURE 4. The center of chain 19 is indicated diagrammatically at 38. It will be noted that hanger assembly 15 is, in this instance, near the extreme left end of its range of adjustment since roof belt 14 is oh line to the outside with respect to its associated wire rope 8 a distance indicated at 39a. Likewise, the entire suspension assembly is located a substantial distance from the spreader bar rope clamp 27 since the roof bolt is located a considerable distance 3% in a longitudinal direction away from the intersection of the spreader means 28 and rope 8. The particular location of the roof bolt is of no concern, however, as long as it is within the transverse range of adjustment of my hanger assembly.

The situation is substantially the reverse with respect to suspension assembly 40. In this instance roof bolt 41 has been located off center to the outside of its associated wire rop 9 a distance 42a, so hanger assembly 15 is in almost the extreme right position in its range of adjust ment. In this instance the distance 42b is somewhat shorter than 3911 since the roof bolt is located closer in a longitudinal direction to the intersection of spreader means 28 and rope 9 than was roof bolt 14, although further from the rope in a generally transverse direction.

FIGURE illustrates the flexibility of my suspension assembly. In this instance the spreader member 45 has rope clamps 46 and 47 integral with its ends. In this as sembly the chains 19 terminate at the rope clamps 46, 47. Since the roof bolts 48, 49 have again not been directly vertically aligned with the rope clamps 46, 47, the suspension assemblies 50, 51 have been rotated in order to bring the chain centers 38 exactly into position. In this instance the suspension assemblies 15 have been rotated with respect to the roof bolt 48, 4h, said rotation in effect providing an adjustment in both longitudinal and transverse directions.

This two directional adjustability is desirable because the chain 19 is secured to the spreader bar rope clamp (rather than to a separate clamp as in FIGURE 4). The chain centers 38 must line up exactly transversely with one another, as well as longitudinally with the ropes, so that rope gauge is not affected. Should the spreaders be skewed, the gauge will not be held.

A second embodiment of my invention is illustrated in FIGURE 6. In this embodiment the mounting plate 59 includes a flat upper portion 60 which terminates in a downwardly depending generally vertically oriented portion 61. Portion 61 includes an elongated, generally horizontally oriented slot 62. A plurality of generally vertical slots 63 are formed along the bottom edge of horiz'ontal slot 62. The width of each of slots 63: is sufiiciently wide to receive a vertically oriented chain link, but sufficiently narrow to prevent passage of a succeeding horizontally oriented link therethrough, so that each slot in effect serves as a lock, much as the keyhole slot 18 in the FIGURE 1 embodiment. A chain is indicated at 64. Its lower end is secured to rope clamp 21 as before and its upper terminal end hangs loose as at 64a. The effective length of the chain, and therefore the distance between wire rop 8 and mounting plate 59 is varied by placing any selected link in one of the slots 63. In this arrangement the chain 64 is adjustable horizontally in substantially equal increments as contrasted to the sliding adjustment of the FIGURE 1 embodiment.

The third embodiment is illustrated in FIGURE 7. In this embodiment the plate member 65 includes a flat upper generally horizontal portion 6-5 and a downwardly depending portion 67. An elongated generally horizontally oriented smooth slot 68 is formed in vertical portion 67. A plurality of downwardly open notches or slots 69 are formed in the lower edge of vertical portion 67.

Each slot is of a width sufficiently wide to receive the shank of a fastener, in this instance bolt 70. The shank of the fastener is small enough to pass through an individual link, and long enough to pass through both portions 71 chain and portion 72 of the chain. A conventional bolt and nut may be used; The effective distance between flat plate 66 and the wire rope 8 is adjusted by pulling downwardly on the terminal portion 72 of the chain. When a correct height is reached, the fastener or bolt 70 is slipped into aligned links in the working and terminal portions of the chain and secured thereto by a suitable nut. As in the FIGURE 6 embodiment, incremental horizontal adjustments are provided.

The fourth embodiment is illustrated in FIGURE 8. In this embodiment the plate portion 74 consists of an intermediate plate 75 flanked by a pair of downwardly depending portions '76, 77.

Keyhole slots

78 and 79 are formed in downwardly depending portions 76, 7'7, respectively. The lower end of chain 80 is connected to rope clamp 21 as in earlier described embodiments. The chain then extends uuwardly to keyhole slot 78, then spans the distance between

plates

76 and 77, passes through keyhole slot 79, and is then brought back and aligned with the working portion of chain 89. A suitable fastener, such as a bolt 81, passes through overlying links in the overlapping lengths of chain to secure the chains to one another. By varying the position of fastener 81, the position of chain 80 can be varied across the distance spanned by depending

flanges

76, 77, without resetting the chain in keyhole slot 73. The shank in the chain between the keyhole slots provides additional adjustment which may be made without disturbing bolt 81.

A fifth embodiment of my invention is illustrated in FIGURE 9. In this embodiment plate member includes an upper flat portion 86 and a downwardly depending portion 87. A keyhole slot 88 and an aperture 89 are formed in depending portion 87 at a substantial distance from one another. The lower end of a length of chain 90 is secured to rope clamp 21 as before. It then passes upwardly through aperture 89, to and through, keyhole slot 83, and is then brought back and secured to the downwardly extending portion of the chain by fastener 91. It will again be noted that, as in the FIGURE 8 embodiment, the position of the depending chain 90 can be varied the distance between the keyhole slot 38 and slot 89 by merely aligning appropriate links in the free end and working end of the chain. Keyhole slot 88 serves as a lock to prevent slippage of the chain.

The use and operation of my invention are as follows:

An infinite choice of adjustments is provided by the preferred embodiment of FIGURE 1. Referring for example to FIGURE 4, the location of

roof bolts

14 and 41 is quite typical of the location of roof bolts in underground mining operations, particularly coal mines. Because of the cramped working conditions and the necessity of installing a conveyor in the shortest possible time, the bolts are placed in reasonably accurate, but not dead center, positions. Even though the roof bolts are not exactly positioned over the rope, the chains 19 can be made to hang exactly vertical over a rope by merely loosely tightening screw 25, sliding hanger assembly 15 along flange 13 until chain 19 is exactly vertical and then retightening screw 25. Tightening of the screw forces the abutting surfaces of lip 17 and flange 13 into abutting, frictional engagement and prevents any movement of hanger 15 along flange 13. suspending chain 19 moves forward and backward with longitudinal shifting of wire rope 8, and at no time does the action of the chain in any way affect the running condition of the conveyor belt. It will be understood of course that rope clamp 21 is positioned as closely as possible in alignment with the intersection of the rope 8 and flange 13. If the rope clamp to which chain 19 is secured is made integral with a spreader means, as shown in FIGURE 5, the plate memher 50 or 51 is first rotated about its roof bolt 48 or 49 in order to cause flange 13 to be aligned with the intersection of the spreader bar rope clamps and wire ropes.

In the second embodiment, FlGURE 6, member 69 is positioned as accurately as possible and then chain 64 is placed in the nearest slot 63.

In the third embodiment, FIGURE 7, plate 66 is positioned as accurately as possible and then chain '71 is threaded through slot 68. Overlapping links on opposite sides of plate 67 are secured to one another by fastener 79. Since the length of the looped portion of chain 71 is less than the distance between the lower edge of slot 5% and the bottom of plate 67, the chain will not slide along the slot.

In the fourth embodiment, FIGURE 8, plate 75 is first positioned as accurately as possible. Fastener 81 is then inserted through overlapping links in the lengths of chain extending downwardly from each or" the keyhole slots.

In the th embodiment, FIGURE 9, plate member 85 is first positioned and then chain 99 is threaded through aperture 89, keyhole slot 83, and then brought back to and aligned with the downwardly extending portion 9% of the chain. Fastener 91 then secures the lengths of chain to one another much as in the third and fourth embodiments. The alignment of vertical portion 9! of the chain can be varied by placing succeeding or preceding lengths or" chain in the keyhole slot, and this can be done without removing fastener 91.

It will be noted with respect to all embodiments that the mounting plates 5, 59, 65, '74 and 35 are adjustable about roof bolt 14 as a connecting point to locate the associated suspending

members

13, 64, 71, 3d and 90 at any desired point in a circle or an arc of a circle, whose radius is the distance from the roof bolt to the suspending member. Further, in each embodiment, the suspending member is movable along a path which passes through a point on the arc scribed by the suspending member as it moves about around the connecting bolt. The path of movement of the suspending member may be chordial or tangential, as in FIGURES 1, 6, 7 and 9, or radial as in FIGURE 8. It will be further noted that the downwardly directed force imposed on each anchor member by its suspending member will be resisted by a counter balancing force bearing against the upper surface of the anchor member at a location generally to the opposite side of the connecting member 14.

It should be understood that when referring to the intersection of a particular part of the suspension assembly located near the upper end of the chain with a wire rope, the intersection of a vertical proiection of the part is intended.

Although a preferred embodiment and four alternative embodiments of my invention have been illustrated and described, it will be apparent to one skilled in the art that other variations may be made within the spirit and scope of my invention. Accordingly it is my intention that the scope of my invention should only be limited by the scope of the pertinent prior art and the following appended claims.

I claim:

1. A conveyor sideframe suspension assembly for suspending a conveyor component from an elevated support location, said conveyor sideframe suspension assembly including a substantially rigid anchor member, mounting structure for mounting the anchor member for generally horizontal movement about a vertical axis, a suspending member depending from the anchor member, means for moving the suspending member relative to the anchor member to thereby vary the radial distance and angular displacement of the suspending member from the vertical axis,

said anchor member having a bearing surface located a substantial distance from the vertical axis in all relative positions of the suspending member to the anchor member,

said vertical axis being located generally between the bearing surface and the suspending member,

whereby force may be imposed on the ancho memberv in a direction to counterbalance the force imposed on the anchor member by the suspending member.

2. The suspension assembly of claim 1 further including means for locking the suspending member to the anchor member, said locking means enabling the length of the suspending member to be varied.

3. The suspension assembly of claim 2 further characterized in that the locking means includes a projection and a plurality of associated apertures, each of said apertures being of a size suificient to receive the projection, said projection and apertures being carried by the anchor member and suspending member, and being eifect-ive, when engaged, to prevent movement between the two.

4. The suspension assembly of claim 2 further characterized in that the locking means includes .a screw engageable with the suspending member and anchor member.

5. Structure for maintaining the gauge of and suspending a pair of wire rope sideframes in a wire rope sideframe conveyor from elevated support locations, such as a pair of roof bolts, said structure including, in combina-tion,

a pair of primary support members and means for securing said members to elevated support locations,

a pair of hanger assemblies, one for each of the primary support members, each hanger assembly being suspended from an associated primary support member,

each of said hanger assemblies including an elongated,

downwardly depending suspending member,

means for varying the length of each of the downwardly depending suspending members alternately or simultaneously,

means for moving each support member and its associated suspending member along an arcwhose center is the point of connection of the support member to its elevated support location,

means for moving each suspending member along a path which passes through the point of .tangency of the suspending member with respect to its arc of movement, and

spreader means for maintaining the wire ropes a fixed distance apart,

said spreader means comprising an elongated rigid structure and means for connecting it to the sideframes,

said connecting means including means for connecting the lowermost end of each suspending member to an associated end of the spreader means.

6. A suspension assembly for suspending a wire rope sidef-rame in a wire rope sideframe conveyor from an elevated support location, such as a roof bolt, said suspension assembly including, in combination,

a plate member,

means for securing said plate member to an elevated support location, said means comprising an aperture of a size sufiicient to receive an anchoring bolt, a hanger assembly suspended from the plate member, each hanger assembly including a hanger, said hanger terminating at its upper end in .a reverse curved portion'of a size sufiicient'to receive therein a complementary reverse curved flange formed on the downwardly depending portion of the plate member, said hanger assembly further having a keyhole slot therein,

an elongated downwardly depending suspending member, such as a chain,

the upper end of the chain being received in the keyhole slot and the lower end of the chain being constructed and arranged for connection to a rope clamp secured to a wire rope sideframe to be supported thereby,

said hanger being slidable along the flange portion of the plate member whereby the position of the keyhole slot, and consequently the suspending member depending therefrom, may be adjusted the length of the flange portion,

and means for securing the hanger to the plate member,

said means comprising a threaded bolt extending through the hanger and effective, when tightened, to force said hanger into engagement with the fiange portion of the plate member.

7. A suspension assembly for suspending a wire rope -sideframe in a wire rope sideframe conveyor from an ele* vated support location, such as a mine roof, said suspen sion assembly including, in combination.

a substantially rigid anchor member comprising a plate,

mounting structure for mounting the anchor member for generally horizontal movement about a vertical axis,

said plate having a downwardly depending portion,

said downwardly depending portion having an elongated generally horizontally oriented slot therein, said slot having a plurality of generally vertical parallel slots opening thereinto, each slot being of a size sufi'icient to receive and lock therein a suspending member,

a downwardly depending suspending member, such as a chain, receivable in any generally vertical slot in the plate member,

the radial distance and angular displacement of the suspending member from the vertical axis being thereby variable,

said vertical axis being located generally between the bearing surface and the suspending member whereby force may be imposed on the anchor member in a direction to counterbalance the force imposed on the anchor member by the suspending member said suspending member being constructed and arranged for connection to a wire rope sideframe or associated wire rope engaging structure at its lower end.

8. A suspension assembly for suspending a wire rope sideframe of a wire rope sideframe conveyor from an elevated support location, such as a mine roof, said suspension assembly including, in combination,

a substantially rigid anchor member comprising a plate,

said plate having a downwardly depending portion, said downwardly depending portion having an elongated substantially smooth generally horizontally oriented slot therein,

the lower edge of said downwardly depending portion having a plurality of generally parallel, generally vertical slots formed therein,

a suspending member, said suspending member being a chain, and

iheans for moving the suspending member relative to the anchor member to thereby vary the radial distance and angular displacement of the suspending member from the vertical axis,

a releasable securing member engageable with the chain for adjusting the length of the chain,

said releasable securing member being of a size suflicient to be received in any one of the slots and connected to a pair of chain links, one link lying on each side of the downwardly depending portion,

the lowermost end of such chain being constructed and arranged for connection to a wire rope sideframe or associated sideframe engaging structure,

said anchor member having a bearing surface located a substantial distance from the vertical axis in all relative positions of the suspending member to the anchor member, said vertical axis being located generally between the bearing surface and the suspending member whereby force may be imposed on the anchor member in a direction to counterbalance the force imposed on the anchor member by the suspending member.

9. A suspension assembly for suspending a wire rope sideframe of a wire rope sideframe conveyor from an elevated support location such as a mine roof, said suspension assembly including, in combination,

a substantially rigid anchor member comprising a plate having a generally flat intermediate portion and a pair of chain receiving portions depending downwardly therefrom,

said mounting structure including an aperture in the intermediate portion for reception of a roof bolt whereby the plate member may be secured to a mine roof by a roof bolt,

each of the downwardly depending flanking portions having a keyhole slot therein of a size sufiicient to receive and lock therein a suspending member,

said suspending member comprising a chain, one end of said chain being constructed and arranged for securement to a wire rope sideframe or structureassociated therewith, said chain passing upgvardly and extending through the keyhole slot memers,

the opposite end of said chain extending downwardly to that portion of the chain extending to the first keyhole slot, and

a securing member for releasably securing the downwardly depending portions of the chain together to thereby vary the position of the chain with respect to the wire rope sideframe,

said anchor member having a bearing surface located a substantial distance from the vertical axis in all relative positions of the suspending member to the anchor member, said vertical axis being located generally between the bearing surface and the suspending member whereby force may be imposed on the anchor member in a direction to counterbalance the force imposed on the anchor member by the suspending member. 10. A suspension assembly for suspending the wire rope sideframe of a wire rope sideframe conveyor from an elevated support location such a a mine roof, said suspension assembly including, in combination,

a substantially rigid anchor member comprising a plate member having a generally fiat, generally horizontally oriented portion and generally vertical portion extending downwardly therefrom,

said mounting structure including an aperture in the generally horizontal portion of a size sufiicient to receive a roof bolt whereby the plate member may be bolted to a mine roof by the roof bolt,

said downwardly depending vertical portion having a keyhole slot and an aperture therein, said slot and aperture being spaced a substantial distance one from the other,

a suspending member comprising a length of chain, said length of chain being adapted for connection at its lowermost end to a wire rope sideframe or a structure associated therewith,

said chain extending upwardly through the aperture and through the keyhole slot,

said chain terminating in a generally vertically oriented portion overlapping the upwardly extending portion, and

a fastener for releasably securing the overlapping portions one to another whereby the position of the chain between the plate member and wire rope sideframe may be etfect-ively varied by securing the chains to one another by the fastener,

said vertical axis being located generally between the bearing surface and the suspending member whereby force may be imposed on the anchor member in a direction to counterbalance the force imposed on the anchor member by the suspending member.

References Cited by the Examiner UNITED STATES PATENTS SAMUEL F. COLEMAN, Primary Examiner.

15 WILLIAM B. LA BORDE, Examiner.

Claims

1. A CONVEYOR SIDEFRAME SUSPENSION ASSEMBLY FOR SUSPENDING A CONVEYOR COMPONENT FROM AN ELEVATED SUPPORT LOCATION, SAID CONVEYOR SIDEFRAME SUSPENSION ASSEMBLY INCLUDING A SUBSTANTIALLY RIGID ANCHOR MEMBER, MOUNTING STRUCTURE FOR MOUNTING THE ANCHOR MEMBER FOR GENERALLY HORIZONTAL MOVEMENT ABOUT A VERTICAL AXIS, A SUSPENDING MEMBER DEPENDING FROM THE ANCHOR MEMBER, MEANS FOR MOVING THE SUSPENDING MEMBER RELATIVE TO THE ANCHOR MEMBER TO THEREBY VARY THE RADIAL DISTANCE AND ANGULAR DISPLACEMENT OF THE SUSPENDING MEMBER FROM THE VERTICAL AXIS, SAID ANCHOR MEMBER HAVING A BEARING SURFACE LOCATED A SUBSTANTIAL DISTANCE FROM THE VERTICAL AXIS IN ALL RELATIVE POSITIONS OF THE SUSPENDING MEMBER TO THE ANCHOR MEMBER, SAID VERTICAL AXIS BEING LOCATED GENERALLY BETWEEN THE BEARING SURFACE AND THE SUSPENDING MEMBER, WHEREBY FORCE MAY BE IMPOSED ON THE ANCHOR MEMBER IN A DIRECTION TO COUNTERBALANCE THE FORCE IMPOSED ON THE ANCHOR MEMBER BY THE SUSPENDING MEMBER.