ROBERTS DAVID (US)
EDWARDS ROWLAND (GB)
CHECKETT MARION DOROTHY & HF (GB)
ROBERTS DAVID (US)
EDWARDS ROWLAND (GB)
| DE29614697U1 | 1996-10-24 | |||
| DE2217567A1 | 1973-10-18 | |||
| FR2396562A1 | 1979-02-02 | |||
| DE2911952A1 | 1980-10-09 | |||
| DE3331097A1 | 1985-03-14 |
| 1. | An anchor for use in rock climbing, the anchor comprising an expansion bolt secured to a mounting on one side thereof and extending therefrom for insertion into a bore formed in a rock face and, on the other side of the mounting, an operating member for expanding and releasing the expansion bolt. |
| 2. | An anchor as claimed in claim 1 wherein the expansion bolt comprises a generally cylindrical member secured at one end to the mounting and having a conical element received in its other end, the conical element being connected through the generally cylindrical member to the operating member so that operation of the operating member causes the conical element to move axially with respect to the generally cylindrical member for expanding and releasing the expansion bolt. |
| 3. | An anchor as claimed in claim 2 wherein the generally cylindrical member comprises a plurality of separate parts which are retained in a generally cylindrical configuration by means of an encircling spring member, the parts being movable generally radially under the action of said conical element for expanding and releasing the expansion bolt. |
| 4. | An anchor as claimed in claim 2 wherein the generally cylindrical member comprises a tubular element having its said other end divided into a plurality of parts capable of being expanded and released by the action of the conical element. |
| 5. | An anchor as claimed in claim 2 or 3 or 4 wherein the conical element is connected to the operating member by means of a flexible component. |
| 6. | An anchor as claimed in any of the preceding claims wherein said operating member comprises a lever formed to have an overcentre action between positions whereat the expansion bolt is expanded and released. |
| 7. | An anchor as claimed in claim 6 as dependent upon any of claims 2 to 5 wherein the operating lever has first and second surfaces which are adapted to seat against the said other side of the mounting when the expansion bolt is in its expanded and released conditions, and the location whereat the conical element connects to the operating lever is more distant from said first surface than it is from said second surface. |
| 8. | An anchor as claimed in claim 7 wherein said first and second surfaces are defined by edges of said operating lever which are substantially perpendicular to each other. |
| 9. | An anchor as claimed in any of the preceding claims wherein the operating member has an attachment point for a karabiner. |
| 10. | An anchor as claimed in any of the preceding claims wherein the operating member employs spring bias for expanding the expansion bolt and means are provided for enabling the operating member to be primed against said spring bias so as to retain the expansion bolt in released condition until the operating member is operated. |
| 11. | A releasable anchor for use in rock climbing, the anchor comprising an expansion bolt for insertion into a bore in a rock face and a quickrelease operating mechanism for expanding the bolt and for releasing the expanded bolt. |
| 12. | A method of providing a temporary anchor to a surface, said method comprising inserting an anchor bolt into a bore formed iri said surface and expanding said anchor bolt by use of a quickrelease mechanism so as to provide an anchor to said surface, and thereafter, when the anchor is no longer required, releasing said quickrelease mechanism and removing the anchor bolt from the bore. |
| 13. | A method as claimed in claim 12 wherein the anchor bolt is constituted by the expansion bolt of the anchor claimed in any of claims 1 to 11. |
| 14. | A method as claimed in claim 12 or 13 including providing a liner in said bore and leaving the liner in place when the anchor is removed. |
| 15. | An anchor as claimed in any of claims 1 to 11 and substantially as herein described with reference to any of the accompanying drawings. |
Field of the Invention:
This invention concerns improvements relating to anchors for rock climbing, that is to say protective devices which can be secured to a rock face to enable the lead climber of a team to secure himself to the rock and thereby reduce the likelihood of serious injury resulting from a fall.
Background of the Invention: Various forms of protective devices are presently available to the rock climbing fraternity. Where a rock face has naturally occurring cracks and fissures, camming devices such as the so-called "Camalots" manufactured by Black Diamond Equipment Limited, the so-called "Friends" and "Flexi Friends" manufactured by Wild Country and the so-called "Quadcams" manufactured by HB enable an anchorage to the rock face to be established, such camming devices having active elements which can be moved into a narrow- or low-profile arrangement for insertion into a crack and, once inserted, can be opened to grip the sides of the crack with a force which increases as the device is loaded with the weight of the climber. Other
devices, such as Black Diamond "Stopper Nuts", Wild Country "Rocks" and "Wallnuts" manufactured by DMM International Limited are passive devices which simply wedge into a rock crevice. Such protective devices are commonly used by "classical" rock climbers who ascend a climb by taking advantage only of whatever natural holds are available and it is a familiar sight in rock-climbing circles to see a climber beginning an ascent with his belt festooned with all manner of active camming devices and passive chocking devices.
Modern rock climbing eschews the limitations of the classicists and unclimbable rock faces bereft of natural holds and/or with formidable overhangs are the playground of today's modern rock climber. The technique here is for the lead climber to locate and fix a series of anchorages each of which provides a secure location from which he can secure the next anchor point which, in a particularly difficult section, may be but an arm's length distant. The lead climber typically carries a rock-drill with which he can bore into the rock face, a supply of expansion bolts such as are commonly used in the construction industries (RAWL™ bolts, for example) and a supply of anchor brackets to be affixed to the rock face by means of the expansion bolts, the anchor brackets providing for the attachment thereto of a karabiner
for securing the climber. The climb thus progresses with a series of bores being drilled into the rock face, expansion bolts being inserted and tightened off with a spanner and a series of anchor brackets thereby being secured to the rock face.
It has traditionally been the practice to leave in position anchor brackets thus fixed to rock faces, the rationale for this being that their removal by the tail end climber would substantially slow down the progress of the climb. Additionally, other climbers coming subsequently to attempt the same climb have been able to take advantage of the previously fitted anchor brackets, which has had advantages in opening up the climb to possibly less-skilled exponents of the sport without subjecting them to undue risk. However, it has recently been appreciated that the leaving of anchor ironmongery in position on rock faces not only has an environmental disadvantage, but also gives rise to potential legal liability. If a park authority permits climbers to ascend rock climbs which it knows have been climbed before and which retain anchors fixed by previous climbers, possibly some months or even years previously, then does the park authority bear a responsibility for ensuring the safety of such anchorages and does it carry a liability if a climber suffers injury or death through failure of such an
anchorage ? Considerations such as these could have a most profound effect upon the future of modern rock- climbing.
In the December 1995 issue of the climbing magazine On The Edσe there is briefly described a prototype removable anchor which was designed and manufactured by one of the inventors of the present invention. The prototype anchor comprised a RAWL™ bolt secured to a mounting plate on one side thereof and extending therefrom for insertion into a bore formed in a rock face. A U-shaped metal piece was welded to the head of the RAWL™ bolt to enable the bolt to be expanded and released more readily than by use of a spanner. The prototype anchor proved successful in use and established to the satisfaction of its inventor that removable anchors promised a solution to the problems abovementioned.
Summary of the Invention:
According to the present invention in one of its aspects there is provided a releasable anchor for use in rock climbing, the anchor comprising an expansion bolt for insertion into a bore in a rock face and a quick-release operating mechanism for expanding the bolt and for releasing the expanded bolt. More particularly, according to a further aspect
of the invention, there is provided an anchor for use in rock climbing, the anchor comprising an expansion bolt secured to a mounting plate on one side thereof and extending therefrom for insertion into a bore formed into a rock face and, on the other side of the mounting plate, an operating lever for expanding and releasing the expansion bolt.
In an exemplary embodiment of the abovementioned further aspect of the present invention, the expansion bolt comprises a generally cylindrical member secured at one end to the mounting plate and having a conical element received in its other end, the conical element being connected through the generally cylindrical member to the operating lever so that operation of the operating lever causes the conical element to move axially with respect to the generally cylindrical member for expanding and releasing the expansion bolt. The generally cylindrical member of this embodiment can for example comprise a plurality of separate parts which are retained in a generally cylindrical configuration by means of an encircling spring member, the parts being movable generally radially under the action of said conical element for expanding and releasing the expansion bolt. Alternatively, the generally cylindrical member can comprise a tubular element having its end distant from the mounting plate
divided into a plurality of parts capable of being expanded and released by the conical element.
The conical element of such an embodiment is preferably connected to the operating lever by means of a flexible component, such as a short length of wire rope for example. Such an arrangement can ensure reliable releasability of the expansion bolt even if, through whatever cause (mishandling for example) , the expansion bolt is somewhat bent in use. Depending upon the particular construction of the expansion bolt and of the conical element, such a flexible component may require a degree of longitudinal rigidity so as to be capable of transferring bolt releasing movement of the operating lever sufficiently forcefully to the conical element.
A suitable quick-release operating lever might for example have an overcentre action between positions whereat the expansion bolt is expanded and is released. Such a lever arrangement could be arranged to provide for easy manual operation of the anchor and could furthermore be arranged as a safety measure so that, in use, movement of the lever from its operated (expansion bolt expanded) to its released
(expansion bolt released) condition causes an initial increase in the force(s) tending to expand the anchor bolt.
The invention also extends to an anchor for use in rock climbing, the anchor comprising an expansion bolt secured to a mounting on one side thereof and extending therefrom for insertion into a bore formed in a rock face and, on the other side of the mounting, manually operable means for expanding and releasing the expansion bolt.
In yet a further embodiment of the invention as hereinafter described in detail, the expansion bolt is a generally tubular RAWL™ bolt which can be radially expanded by drawing a conical expander element into the bore of the bolt. The RAWL™ bolt is secured to a mounting which provides a finger grip for inserting the bolt into a drilled hole and for withdrawing the bolt from the hole. The conical expander element is screw-threadedly coupled to one end of an operating member which extends through the tubular bore of the bolt and through the mounting to become accessible for manual operation on the other side of the mounting. The operating member preferably includes a flexible portion, constituted for example by a short length of wire rope, and is preferably spring biassed towards an operated (bolt expanded) condition.
The invention also extends to a method of providing a temporary anchor to a surface, said method comprising inserting an anchor bolt into a bore formed
3 in said surface and expanding said anchor bolt by use of a quick-release mechanism so as to provide an anchor to said surface, and thereafter, when the anchor is no longer required, releasing said quic - release mechanism and removing the anchor bolt from the bore.
The above and further features of the present invention are set forth in the appended claims and, together with advantages thereof, will become more clear from consideration of the following description given with reference to the accompanying drawings.
Brief Description of the Drawings:
Figure 1 shows an exploded perspective view of a first embodiment of the present invention; Figure 2 shows an exploded side elevation view of a second embodiment of the present invention;
Figure 3 shows an exploded side elevation view of a third embodiment of the present invention;
Figures 4A to 4J are views showing the component parts of the third embodiment in more detail, Figures 4A and 4B showing an outer cylindrical component of the expansion bolt in side and sectional views, Figures 4C and 4D showing the mounting plate in front and side elevation views and Figure 4E showing the component of Figures 4A and 4B secured to the mounting
plate, Figures 4F and ΛG showing the conical expander element of the expansion bolt in side and end elevation views, Figure 4H showing in side elevation view a component serving to connect the conical expander element to the operating lever, and Figures 41 and 4J showing front and side elevation views of the operating lever;
Figure 5 shows an exploded side-elevation view of another embodiment of the present invention; Figure 6 shows a top plan view of the assembled embodiment of Figure 5 in open (released or non-expanded) condition;
Figure 7 shows a view similar to Figure 6 but with the embodiment in locked (expanded) condition; Figure 8 is an exploded side elevational view of yet another embodiment of the invention; and
Figure 9 is a schematic side elevational view of another embodiment of the invention.
Detailed Description of the Embodiments: Referring first to Figure 1, there is shown therein a first exemplary embodiment of the present invention which comprises an expansion bolt 1 arranged to be secured to a mounting plate 2 and operated by means of a quick-release lever 3. The expansion bolt 1 in this embodiment is a generally cylindrical hollow
member formed as two parts 4 and 5 which are held together by means of a spring circlip 6, and a conical element 7 is provided which fits into the end of the expansion bolt 1 and is movable axially with respect to the expansion bolt so as to determine the condition, expanded or released, of the expansion bolt. A connecting rod 8 is coupled to the conical element 7 and extends through the hollow centre of the expansion bolt and through an opening 9 formed in the mounting plate 2 for connection to the operating lever 3, a through hole 10 being formed in the end of the connecting rod 8 for receiving a pin 11 which couples the rod to the operating lever. A spring 12 sits between the mounting plate 2 and the operating lever 3.
The end of the expansion bolt 1 which is received in the opening 9 in the mounting plate is necked-in, and the periphery of the opening 9 is formed with a profile generally complementary to the necked-in part so that the expansion bolt is firmly though loosely secured to the mounting plate. The conical element 7 is screw-threadedly engaged with the connecting rod 8 so that the effective length of the connecting rod is adjustable during assembly of the anchor device to accommodate tolerance variations in the sizes of the components. The operating lever 3 has a U-shaped or
yoke portion 13 formed with cam surfaces 14 which bear against the front face of the mounting plate 2, and an upstand 15 from the yoke portion 13 has an opening 16 for attachment of a karabiner to the operating lever. The mounting plate 2 has an upstand 17 and an opening 18 is provided in this upstand.
As will readily be appreciated, when the thus described anchor is assembled, the position of the operating lever 3 relative to the mounting plate 2 will determine whether the expansion bolt 1 is expanded or whether it is released. With the operating lever 3 in the position shown in Figure 1 the location of pin 11 will be relatively close to the front face of the mounting plate 2 and the expansion bolt will be in its released (not expanded) condition. If the operating lever is turned through 90° in a clockwise direction, the pin 11 will move away from the front face of the mounting plate 2 under the action of the cam surfaces 14, the conical element 7 will be pulled into the expansion bolt 1 by the connecting rod 8, and the two parts 4 and 5 of the expansion bolt will be driven apart.
The utility of the described anchor in the field of rock climbing will readily be appreciated. With the expansion bolt 1 in its released (not expanded) condition, the bolt 1 can be inserted into a bore
drilled into a rock face and the operating lever 3 can then be turned so as to expand the bolt within the bore and thus secure the anchor. When it is subsequently desired to remove the anchor, the lever 3 can quickly be restored to its original position thus enabling the expansion bolt 1 to be withdrawn from the bore in the rock face. It will be seen that the lever 3 has an overcentre action in that, when it is moved from its bolt-released to its bolt-expanded positions and vice versa it moves through a position whereat the pin 11 is even further spaced from the mounting plate 2 so that an even greater force is transmitted to the conical element 7.
Figure 2 shows an alternative embodiment of the invention and employs the same reference numerals as are employed in Figure 1 for like parts. In this embodiment, the connecting "rod" 8 is formed as a head portion 20 adapted to be secured to the operating lever 3 by means of the pin 11, a flexible portion 21 formed as a short length of wire rope secured to the head portion 20 at one end and secured at its other end to a bolt 22 which is screw-threaded at 23 for engagement with the conical expander element 7. The lateral flexibility of the portion 21 ensures the continued functionability of the anchor in the event that the expansion bolt is damaged in such a manner as
would cause a rigid connecting rod (such as that of the first embodiment) possibly to jam.
The anchor of Figure 3 is very similar to that of Figure 2 except that the expansion bolt 1, which in the first and second embodiments is constituted by a commercially available RAWL™ bolt, is formed of a tubular metal sleeve 30 provided with four evenly spaced-apart slots 31 in its free end and cold welded or otherwise secured into the opening 9 in the mounting plate 2. The slots 31 enable the metal sleeve 30 to be expanded by the conical element 7 and to resile when the element 7 is withdrawn from the open end of the sleeve. The detailed form of the component parts of this embodiment are shown in Figures 4A to 4J and will not be described further except to point to the lugs 35 that are provided on the conical expander element 7 for engaging in the slots 31 in the sleeve 30 to prevent rotation of the element 7 about the bolt 22 once the anchor has been assembled.
It will be noted that the mounting plate 2 in the embodiments of Figures 2 and 3 is simplified as compared to that of the Figure 1 embodiment. In the Figures 2 and 3 embodiments, the mounting plate 2 simply has an inclined portion 36 which provides a finger grip for facilitating removal of the released
anchor. The Figures 2 and 3 embodiments could if desired have a mounting plate similar to that of the Figure 1 embodiment.
The mounting plate 2 and the operating lever 3 of the Figure 3 embodiment are preferably formed of aluminium for reducing the weight of the assembled anchor. All other components of the embodiment are preferably formed of stainless steel.
Figures 5, 6 and 7 show yet another embodiment of the invention and again use the same reference numerals as were used to designate like parts in the description of the previous embodiments.
Referring to Figure 5, an expansion bolt 1, constituted by a commercially available RAWL™ bolt, is arranged to have its proximal end received within an accommodating aperture 9 in a mounting 2 which is shaped to provide spaced-apart finger grips 70. The expansion bolt 1 is a generally cylindrical hollow member formed as two parts 4 and 5 which are held together by means of a spring circlip 6, and a conical element 7 is provided which fits into the end of the expansion bolt 1 and is movable axially by means of an operating member 3 to determine the condition, expanded or released, of the bolt 1. The end of the expansion bolt which is received in the aperture 9 is necked-in and the periphery of the aperture 9 is
provided with a generally-complementary profile such that the expansion bolt is firmly though loosely secured to the mounting.
The conical element 7 is adapted to be screw- threadedly engaged with an end portion 22 of a connection piece 8 which further comprises a short length of wire rope 21 and a head portion 20 which is apertured for attachment of a karabiner or of a strap to which a karabiner may be attached. A spring 12 acts between the head portion 20 and the mounting 2 to bias these two parts apart.
Figure 6 shows the anchor device in open (released or non-expanded) condition with the operating member 3 urged towards the mounting 2 against the action of spring 12 so that the conical element 7 is clear of the distal end of expansion bolt 1 and the bolt is in its released or non-expanded condition. Figure 3 shows the operating member 3 urged outwardly so as to draw the conical element 7 into the bore of the RAWL™ bolt and cause it to expand.
The utility of the described embodiment in the field of rock climbing (and in other fields) will readily be appreciated. With the operating member 3 urged towards the mounting 2, the non-expanded bolt 1 can be introduced into a bore drilled into a rock-face
for example. When the operating member 3 is then released, and more so when it is weighted by the weight for example of a climber supported by a karabiner clipped to the operating member, the conical element 7 is drawn into the distal end of the expansion bolt thereby causing it to expand and grip the drilled bore. When it is desired to release the expansion bolt 1, the operating member 3 is unloaded (namely the climber unclips himself and transfers his weight to another anchorage) and can then be manually urged towards the mounting 2 so as to urge the conical element 7 in a direction such as to release the expansion of the bolt 1. It will be appreciated, in this regard, that the wire rope portion 21 must be sufficiently stiff to transfer bolt release forces from the head portion 20 to the conical element 7.
The illustrated mounting 2 in the embodiment of Figures 5, 6 and 7 is formed as an appropriately bent metal plate, but clearly could be otherwise formed. For example, the mounting could be formed as a moulded plastics material finger-hold portion having received therein a hollow cylindrical bush which is open at one end (the end which faces away from the rock face in use) and closed at the other except for an aperture to receive the end of the expansion bolt 1 and to permit through passage of the parts 21 and 22 of the member
8. the operating member 3 might then have a solid cylindrical portion between the parts 20 and 21 which fits into the open end of the bush, in the manner of a piston into a cylinder, capturing the spring 12 inside the bush. The moulded plastics finger-hold portion might be shaped for comfortable accommodation of a user's fingers and could alternatively be formed of forged aluminium or of a suitable metal alloy, in which case the abovementioned bush could be integrally formed rather than being a separate component.
Yet another embodiment of the invention is shown in Figure 8 wherefrom the expansion bolt l, a commercially available RAWL™ bolt as in the embodiment of Figures 5, 6 and 7 for example, and its conical expansion/release element 7 has been omitted. A tubular mounting 2 has its right-hand end formed to receive one end of the expansion bolt, just as the aperture 9 in the mounting 2 of the embodiment of Figures 5, 6 and 7 receives one end of its expansion bolt 1. An operating member 3 is connected by a short length of wire rope 21 to a screw-threaded end portion 22 upon which the conical expansion/release element is adapted to be screw-threadedly received as in the previous embodiment. A head portion 20 of the operating member is apertured for attachment of a karabiner or of a braid strap to which, in turn, a
karabiner may be attached.
The member constituted by the interconnected parts 3, 21 and 22 is adapted to be received within the tubular mounting 2 with a spring 12 interposed between the internal shoulder that is provided at the right-hand end of the bore of the mounting 2 and the shoulder defined at the juncture of parts 3 and 21. The screw-threaded end portion 22 projects from the right-hand end of the mounting 2 for attachment of the conical expansion/release element 7.
A pin 50 extends transversely from the part 3 and locates in a J-shaped slot (not shown) formed in the wall of the mounting 2 such that the spring 12 can be held in compressed condition by pressing the operating member 3 towards the mounting 2 and then turning the operating member through 90°. This serves to hold the expansion bolt in released (non-expanded) condition for insertion of the device into a drilled hole, and enables the bolt to be expanded simply by turning the operating member through 90° in a reverse direction so as to release the pin 50 from the turn in the J-shaped slot and cause the spring 12 to drive the member 8 outwardly of the mounting 2, thereby urging the conical expansion/release element 7 into the end of the expansion bolt so as to expand the same. By virtue of this arrangement, a rock climber can set a
plurality of the devices before the commencement of a climb so that they are ready to be inserted into the bores that he drills without his having to fiddle with them and can be fixed in the drilled bores simply by a quarter turn of the operating member.
A further embodiment is schematically illustrated in Figure 9 and has operating parts substantially as hereinbefore described. The mounting 2 in this embodiment is adapted to be used with a hole drilled at an angle into a rock face and has a limb 2' which ends in a projection 2 ' ' which is adapted to locate in a further small bore drilled into the rock face. This embodiment avoids 90° loading of the device in use, that is to say loading in a direction transverse to the longitudinal axis of the operating parts, and the limb 2 ' prevents rotation of the device and transfers much of the forces applied to the device in use back to the rock face. As in the embodiment of Figure 8, the part 3 may be provided with a pin 50 which is received in a J-shaped groove in the mounting 2 so as to enable the device to be pre-set for operation at the beginning of a climb. The mounting 2 of this embodiment might advantageously be formed to define suitable finger holds, much in the manner of the hereinbefore described modification of the embodiment of Figures 5, 6 and 7 (see the paragraph hereof
immediately preceding the description of the embodiment of Figure 8) , and its operating parts might for example also be as in the said hereinbefore modification of the embodiment of Figures 5, 6 and 7. Having thus described the present invention by reference to exemplary embodiments, it is to be appreciated that modifications and variations thereto are possible without departure from the spirit and scope of the present invention. For example, whereas in the described embodiments the expansion bolt is of a kind which is expanded by pulling a conical element into the open end of an expansible cylinder, the expansion bolt could alternatively be of a kind where expansion is effected by driving a core part down into the hollow centre of the bolt. Other forms of lever, possibly providing increased leverage, could also be used for the operating member of the device.
Whilst the principal utility of the present invention is seen as residing in the field of rock climbing, the described anchor devices could have utility in other fields, for example in the building and construction industries. In the rock climbing field, the utility of the device is not limited to naturally occurring rock faces but extends to artificial climbing walls where pre-for ed bore holes may be provided with a metal liner to strengthen them
and protect them against wear. Indeed, it is within the ambit of the present invention to employ stainless steel bore liners on naturally occurring climbs, such bore liners being in the form of a sleeve capable of being hammered into a drilled bore and possibly including external burrs or other formations such as to prevent its removal from the bore. The sleeve would preferably itself be expansible so as to be capable of being fixed in position by means of a conical wedging piece hammered into the distal end of the sleeve, and capable of transferring to the rock the expansion force developed by the expansion bolt when it is inserted into the sleeve and expanded therein, and the co-operating surfaces of the sleeve and the expansion bolt should preferably be such as to ensure high friction between the two when the expansion bolt is expanded so as to obviate any risk of the expansion bolt pulling out of the sleeve. Indeed, the expansion bolt and the sleeve could be constructed so that a positive engagement was obtained between the two when the bolt was expanded within the sleeve. It would be environmentally acceptable to leave such stainless steel bore liners in place and, since they would not corrode, they would remain a safe anchorage point with the passage of time. Removable plugs could be fitted into the open ends of the
sleeves to make them weathertight when not in use and the sleeves could be secured in the rock with resin to ensure a void free juncture between the sleeve and the rock bore. Such sleeve-lined bores could be provided in the fabric of high-rise buildings for use in the retention of ladders and/or safety equipment as and when required.