WO2015044940A1

WO2015044940A1 - Apparatus and method for installing an anchor within a base material

Info

Publication number: WO2015044940A1
Application number: PCT/IL2014/050796
Authority: WO
Inventors: Dror LEV
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-09-29
Filing date: 2014-09-07
Publication date: 2015-04-02
Anticipated expiration: 2016-03-29

Abstract

In a system and method for installing an anchor, an anchor having a tubular body with a hollow interior, a proximal end defining an annular aperture in communication with the interior, and a longitudinal slot formed in the body is positionable within a hole drilled in a base material. The body has a continuous and uninterrupted outer surface, with the exception of the slot, in both rest and expanded conditions. An expander is linearly drivable through the anchor's proximal end into the interior to induce the anchor to expand at a given circumferential region while minimizing stress concentrations in, and being anchored to, the base material, by virtue of the uninterrupted outer surface. In one embodiment, a driving tool transmits a hammering action generated by a power tool to the expander by a mating element, and alternatively transmits torque to a self-drilling anchor by a spline engageable with the slot.

Description

APPAEATUS AND METHOD FOR INSTALLING AN ANCHOR WITHIN A

BASE MATERIAL

Field of the Invention

The present invention relates to the field of drilling. More particularly, the invention relates to an apparatus and method for installing an anchor within a drilled hole of a base material.

Background of the Invention

A self- drilling anchor is a device which drills a hole into a base material and is then fixed inside the drilled hole by means of an expansion mechanism. There are some advantages to such a device. Firstly, it eliminates the need for using drill bits. Secondly, it reduces the complexity and work time of a drilling operation because there is no need to match the correct drill bit size to the anchor size and then to mark the desired hole depth on the drill bit prior to drilling.

Despite the aforementioned advantages, prior art self- drilling masonry anchors have some drawbacks.

US 3,202,035 discloses a self-boring wall-plug that comprises a hollow body having a toothed front end portion for boring a hole into a hard and compact material, and a frusto-conical rear end portion constituting a detachable operating head for coupling with a chuck. After a hole is bored with the wall-plug, the latter is withdrawn from the hole and an expansion cone is fitted within the front end of the wall-plug. The front end of the expansion cone is then brought in abutment with the hole bottom, and the wall-plug is subjected to the action of percussion means, to drive the cone within the axial passage of the wall-plug, cause radial expansion of the front end portion, and drive the plug further within the hole. The operating head is then sheared off, allowing a screw to be screwed within the tapped portion of the plug. The radial expansion of the front end portion of the plug is facilitated b}^ a plurality of longitudinal grooves formed in the plug body and extending from the teeth. The wall-plug is not easily fabricated, due to the presence of the longitudinal grooves and the detachable operating head. As only circumferential segments of the front end portion, which are defined by the longitudinal grooves, are expanded, the wall-plug expands laterally and non-uniformly, and induces localized stress concentration in the surrounding masonry. When the surrounding masonry is fragmented, the stress concentrations can lead to detachment of masonry particles or a decrease in the gripping force of the anchor.

Other drawbacks of this anchor include the time consuming anchoring procedure of having to remove the anchor from the hole in order to insert the expansion cone, and to shear off the operating head, and that it is suitable for use in solid base materials such as concrete, but not in hollow base materials such as cinder blocks.

DE 1909413 discloses a similar self-drilling anchor that is formed by a rolled blank to define a cylindrical body having a small gap over its entire height that almost touches the edges of the blank.

It is an object of the present invention to provide a self-drilling anchor that reduces stress concentrations within the base material after being drilled, relative to prior art devices.

It is an additional object of the present invention to provide a self-drilling anchor that can be manufactured much more simply, and consequently at a lower cost, than a prior art device. It is yet an additional object of the present invention to provide a self- drilling anchor that is anchorable within hollow base materials.

Other objects and advantages of the invention will become apparent as the description proceeds.

Summary of the Invention

The present invention provides a system for installing an anchor in a base material, comprising an anchor positionable within a hole drilled in a base material and having a tubular main body with a hollow annular interior, a proximal end defining an annular aperture in communication with said hollow interior, and a longitudinal slot formed in said main body! and an expander configured with a portion having a larger outer diameter than the inner diameter of said hollow interior, wherein said main body has a continuous and uninterrupted outer surface, with the exception of said longitudinal slot, in both a rest condition and an expanded condition, wherein said expander is linearly drivable through said proximal end of said anchor into said hollow interior to induce said anchor to expand at a given circumferential region thereof while minimizing stress concentrations in, and being anchored to, the base material, by virtue of said uninterrupted outer surface.

The expander is simultaneously securable to the anchor while the latter is being anchored to the base material.

The outer surface of the anchor is "continuous" by being formed without any voids, with the exception of one or more longitudinal and collinear slots, and is "uninterrupted" in the sense that it is structurally uncompromised, i.e. formed without any weakened or machined regions that could cause bending or any other relative motion aside from radial expansion induced by the expander, although the outer surface may have any desired texture or finishing. The anchor may be a self-drilling anchor or a non-drilling anchor.

In one aspect, the anchor is configured with a portion that radially extends from, the proximal end of the main body, said radially extending portion being positionable in abutting relation with an outer face of the base material or of a fixture fastenable to the base material, through which a reactive force is transmittable. The radially extending portion may be of a shoulder shape that is substantially perpendicular to the proximal end of the main body or may be of a conical shape.

The system preferably further comprises a dedicated driving tool for linearly driving the expander into the hollow interior of the anchor. The driving tool has a proximal end which is engageable with a power tool and a portion which is engageable with the expander.

As referred to herein, "proximal" means in a direction towards a user installing the anchor and away from the base material, if the anchor were introduced within a hole formed in the base material, "distal" means in a direction towards the base material and away from the user, and "longitudinal" means in a direction parallel to the axis of the anchor and along its length.

The present invention is also directed to a self-drilling anchor, comprising a tubular main body with a hollow annular interior, a proximal end defining an annular aperture in communication with said hollow interior, a longitudinal slot formed in said main body, and one or more cutting edges for drilling a hole in a base material formed at a distal end of said main body, wherein said main body has a continuous and uninterrupted outer surface, with the exception of said longitudinal slot, in both a rest condition and an expanded condition, wherein an expander configured with a portion having a larger outer diameter than the inner diameter of said hollow interior is linearly drivable through said proximal end of said anchor into said hollow interior to induce said anchor to expand at a given circumferential region thereof while minimizing stress concentrations in, and being anchored to, the base material, by virtue of said uninterrupted outer surface.

In one aspect, the self-drilling anchor further comprises a plurality of longitudinally spaced, annular gripping elements radially extending from the main body.

The present invention is also directed to a driving tool for facilitating installation of an anchor in a base material, comprising a proximal end engageable with a power tool, and a mating element engageable with an expander configured to expand an anchor positioned within a hole which has been drilled within a base material, for transmitting to said expander a hammering action generated by said power tool.

In one aspect, the mating element is coupleable with a complementary socket formed in the expander.

In one aspect, the driving tool further comprises a spline engageable with a slot formed in the anchor which is a self-drilling anchor, for transmitting to said self- drilling anchor a torque generated by the power tool. The spline is of a minimum width that will be assured of retaining its structural integrity when transmitting torque from the driving tool to the self-drilling anchor and the corresponding slot is sized to receive the spline.

The present invention is also directed to a method for installing an anchor in a base material, comprising the steps of positioning within a hole drilled in a base material, an anchor configured with a tubular main bod}' having a continuous and uninterrupted outer surface with the exception of a longitudinal slot, a hollow annular interior, and a proximal end defining an annular aperture in communication with said hollow interior; partially inserting an expander configured with a portion having a larger outer diameter than the inner diameter of said hollow interior into said proximal end of said anchor; and linearly driving said expander into said hollow interior to induce said anchor to expand while being anchored within the base material.

Brief Description of the Drawings

In the drawings ·

- Fig. la is a perspective view of a non-drilling anchor, according to one embodiment of the present invention!

- Fig. lb is a perspective view of a self-drilling anchor, according to one embodiment of the present invention;

- Fig. 2a is a perspective view of a non-drilling anchor which is provided with a shoulder shape portion;

- Fig. 2b is a perspective view of a self-drilling anchor which is provided with a shoulder shape portion;

- Fig. 3a is a front view of a male expander in alignment with the self-drilling anchor of Fig. lb, shown as a partially cut away front view, prior to being engaged therewith;

- Fig. 3b is a front view of a female expander in alignment with the self-drilling anchor of Fig. lb, shown as a partially cut away front view, prior to being engaged therewith;

- Fig. 3c is a front view of a nail-like expander in alignment with the self-drilling anchor of Fig. lb, shown as a partially cut away front view, prior to being engaged therewith;

- Fig. 3d is a front view of the expander of Fig. 3a after being partially inserted into the self- drilling anchor of Fig. lb; ^■ Fig. 3e is a cross sectional view of an external female expander configured with two portions of different widths, after being fully inserted within the non-drilling anchor of Fig. la;

- Fig. 4a is a front view of a male expander in alignment with the self-drilling anchor of Fig. 2b, shown as a partially cut away front view, prior to being engaged therewith;

- Fig. 4b is a front view of a female expander in alignment with the self-drilling anchor of Fig. 2b, shown as a partially cut away front view, prior to being engaged therewith;

- Fig. 4c is a front view of a nail-like expander in alignment with the self-drilling anchor of Fig. 2b, shown as a partially cut away front view, prior to being engaged therewith;

- Fig. 5a is a perspective view of a self-drilling anchor formed with a slot that partially extends along the length of the main body thereof;

- Fig. 5b is a perspective view of a self-drilling anchor formed with two slots of different widths;

- Fig. 5c is a perspective view of a self-drilling anchor formed with a frangible thin-walled portion 53;

Fig. 5d is a perspective view of a self-drilling anchor formed with a plurahty of self-locking protrusions;

- Fig. 6 is a front view of an expander provided with a pointed distal portion;

- Fig. 7 is a perspective view of a driving tool and the self-drilling anchor of Fig. lb, prior to being coupled together;

- Fig. 8 is a cross sectional view of the driving tool of Fig. 7 and the self-drilling anchor of Fig. lb, when coupled together;

- Fig. 9 is a perspective view of another embodiment of a driving tool and a self- drilling anchor, prior to being coupled together;

- Fig. 10 is a perspective view of an additional embodiment of a driving tool and a self-drilling anchor, prior to being coupled together; ^■ Fig. 11a is a front view of the driving tool of Fig. 7 in alignment with expander of 3a, prior to being engaged therewith;

- Fig. lib is a front view of the driving tool of Fig. 7 in alignment with expander of 3b, prior to being engaged therewith;

- Fig. 11c is a front view of the driving tool of Fig. 7 in alignment with the expander of Fig. 3c, prior to being engaged therewith;

- Fig. 12 is a side view of yet an additional embodiment of a driving tool;

^■ Fig. 13a is a front view of the driving tool of Fig. 12 when coupled together with the expander of Fig. 3a, both shown by partial cross sectional views;

- Fig. 13b is a front view of the driving tool of Fig. 12 when coupled together with the expander of Fig. 3b, both shown by partial cross sectional views;

^■ Fig. 14 is a front view of yet an additional embodiment of a driving tool in alignment with expander of Fig. 3b, prior to being engaged therewith;

- Fig. 15 schematically illustrates in cross sectional view the transmission of a hammering action from the driving tool of Fig. 7 to the self-drilling anchor of Fig. lb so as to be driven to a shallow depth within a base material;

- Fig. 16 schematically illustrates in cross sectional view the transmission of a combined hammering and drilling action from the driving tool of Fig. 7 to the self- drilling anchor of Fig. lb;

- Fig. 17 schematically illustrates in cross sectional view the transmission of a combined hammering and drilling action from the driving tool of Fig. 7 to the self- drilling anchor of Fig. lb, shown to be driven through a fixture fastenable to a base material;

- Fig. 18a is a cross sectional view of the expander of Fig. 3 a when coupled with the driving tool of Fig. 7 and partially inserted within the self-drilling anchor of Fig. lb, prior to an expansion operation;

- Fig. 18b is a cross sectional view of the expander of Fig. 3a when fully inserted within the self-drilling anchor of Fig. lb, schematically illustrating the expansion operation; ^■ Fig. 19a is a cross sectional view of the expander of Fig. 3b when coupled with the driving tool of Fig. 7 and partially inserted within the self-drilling anchor of Fig. lb, prior to an expansion operation;

- Fig. 19b is a cross sectional view of the expander of Fig. 3b when fully inserted within the self-drilling anchor of Fig. lb, schematically illustrating the expansion operation;

- Fig. 20a is a cross sectional view of the expander of Fig. 3c when coupled with the driving tool of Fig. 7 and partially inserted within the self- drilling anchor of Fig. 2b, prior to an expansion operation;

- Fig. 20b is a cross sectional view of the expander of Fig. 3c when fully inserted within the self-drilling anchor of Fig. 2b, schematically illustrating the expansion operation;

- Fig. 21 is a perspective view of the driving tool of Fig. 7 when coupled to the self-drilling anchor of Fig. lb, showing the driving tool spline while fit within the slot of the anchor;

- Fig. 22 is a cross sectional view of the expander head portion of Fig. 3c positioned in pressing relation with the anchor shoulder shape portion of Fig. 2b while in abutment with a fixture fastened to the base material;

- Fig. 23 is a cross sectional view of the anchor shoulder shape portion of Fig. 2b when urged to be in abutting relation with the outer face of a hollow base material prior to being completely anchored within the base material;

- Fig. 24 is a perspective view of another embodiment of a self-drilling anchor;

- Fig. 25 is a side view of the anchor of Fig. 24;

- Fig. 26 is a method for installing an anchor in a base material, according to one embodiment of the invention!

- Fig. 27 is a perspective view of a self-drilling anchor configured with a single oblique cutting surface; and

- Fig. 28 is a cross sectional view of the expander of Fig. 3e being introduced into a self-drilling anchor with the use of a dedicated driving tool. Detailed Description of Preferred Embodiments

The self-drilling anchor of the present invention having a slotted and elongated tubular shape is used for drilling a base material, whether solid masonry or a hollow block, and is subsequently anchored to the base material. The self-drilling anchor has at least one cutting edge at a distal end and is configured at its proximal end so as to be coupled with a dedicated driving tool.

Broadly speaking, as illustrated in Fig. 26, the proximal end, or the end closer to the user and more spaced from the wall to be drilled, of the driving tool is coupled to the power tool and the distal end, or the end closer to the wall to be drilled, of the driving tool is coupled to the self-drilling anchor in step 50. The power tool is then to set to a hammering mode and is activated in step 52 to linearly drive the self-drilling anchor to a shallow depth within the base material. The preliminary bore will help improve the grip of the self-drilling anchor with the base material once drilling begins. The power tool is then set to a combined hammering and drilling mode in step 54 to transmit torque to the self-drilling anchor via the driving tool, so as to perform a drilling operation within the base material in step 56, after which the self-drilling anchor is completely embedded within the base material. Upon completion of the drilling operation, the driving tool is disengaged from the self-drilling anchor in step 58. In step 60, the driving tool is engaged with the proximal end of an expander having an outer diameter larger than the inner diameter of the self-drilling anchor so that the expander will be partially inserted within the proximal end of the self-drilling anchor . When the power tool is set to the hammering mode and activated in step 64, the expander is linearly driven within the anchor, causing the anchor to become enlarged so as to provide the retention force needed for anchoring.

Various embodiments of the self-drilling anchor, driving tool and expander are set forth in the following description. Any combination of the self-drilling anchor, driving tool and expander, or of an anchor and expander are within the scope of the invention.

Fig. lb illustrates a self-drilling anchor according to one embodiment of the present invention, and is indicated generally by numeral 5. Self-drilling anchor 5 has a tubular main body 3 with a hollow interior. Main body 3 is formed with an elongated slot 4 longitudinally extending throughout its length, through which disintegrated base material particles generated during a drilling operation are dischargeable and which increases anchor flexibility during an expansion operation. A plurality of cutting teeth 7 are formed at the distal end 8 of main body 3, for use in drilling a hole in the base material. The outer surface of main body 3 is continuous and uninterrupted for a circumferential distance of greater than 300 degrees, e.g. greater than 340 degrees or 350 degrees, when viewing the longitudinal axis of self-drilling anchor 5, with the exception of the longitudinal slot, from cutting teeth 7 to its proximal end 8, as opposed to prior art self- drilling anchors that are formed with a plurality of distally disposed longitudinal grooves to enable expansion, thereby significantly reducing the complexity and expense of the manufacturing process. This continuous main body configuration reduces or minimizes stress concentration within the base material within which self-drilling anchor 5 is embedded as a result of the substantially uniform expansion of the main body.

Self-drilling anchor 5 may be manufactured from sheet metal and rolled to produce the tubular structure, or alternatively may be extruded or produced by any other manufacturing process to achieve the illustrated structure. Circumferentially spaced cutting teeth 7 may be formed such that their cutting edges are substantially perpendicular, or at any other desired angle, with respect to the outer surface of main body 3. During a drilling operation within base material 55, e.g. concrete, as shown in Fig. 16, self-drilling anchor 5 is coupled to driving tool 40 and the power tool is set to hammering and drilling mode, causing a hole to be drilled. The outer diameter of self-drilling anchor 5 defines the hole's diameter and the length of its main body defines the depth of the hole.

Self-drilling anchor 5 may also be drilled through a fixture 43 that is being joined to base material 55, as shown in Fig. 17.

Figs. 3a, 3b and 3c show three different embodiments of expanders, respectively, which are engageable with self-drilling anchor 5. All of these expanders have a distal portion 6 configured with an outer diameter that is smaller than the inner diameter of the tubular bore 10 of anchor 5, to facilitate initial insertion therewithin. Also, they have a conical portion 13 which gradually increases in size from the relatively small diameter of distal portion 6 to the relatively large diameter of shank 11, which has a larger diameter than the inner diameter of bore 10. Thus the expander, when hammered into self-drilling anchor 5, induces the latter to expand and to therefore be anchored within the base material after being imparted with a suitable retention force.

Male expander 14 shown in Fig. 3a has a proximal portion 19 that is formed with external threading which is adapted to protrude from self-drilling anchor 5 after the expander is fully inserted therewithin. Externally threaded portion 19 is later used with means such as a nut for joining a fixture to the base material.

In Fig. 3d, the conical portion 13 of male expander 14 is introduced slightly beyond proximal end 8 and into the interior bore 10 of self-drilling anchor 5, showing that the outer diameter of shank 11 is greater than the inner diameter of bore 10. Thus full insertion of male expander 14 into bore 10 will cause expansion of main body 3 while self-drilling anchor 5 is becoming anchored within the base material.

Female expander 16 shown in Fig. 3b has internal threading 22, for joining a fixture to the base material with means such as a bolt, screw, and drill rod.

Nail-like expander 17 shown in Fig. 3c has a head portion 23 which is wider than shank 11. This expander is hammered into the self- drilling anchor through a fixture that is being joined until head portion 23 presses the fixture to the base material. Head portion 23 is shown to have a mushroom shape, but it also may be configured in other ways, such as a countersink head and a hexagonal head.

An expansion operation is illustrated in Figs. 18a and 18b.

After the base material 55 has been drilled and self-drilling anchor 5 has been embedded therewithin and disengaged from the driving tool, expander 14 is inserted into self-drilling anchor 5, as shown in Fig. 18a driving tool 40 is coupled to expander 14 and the power tool is set to the hammering only mode in any desired order, to apply a linear force against base material 55. The hammering can be done through fixture 43, or before this fixture is positioned. While the power tool continues to be operated, expander 14 is fully driven within the interior of self- drilling anchor 5, as shown in Fig. 18b. While expander 14 is being linearly driven, the entire main body of self-drilling anchor 5 becomes continuously and progressively expanded, from its proximal end to its distal end, due to the difference between the outer diameter of the expander and the inner diameter of the self-drilling anchor, until a substantially uniform force F is applied to base material 54. Consequently, externally threaded portion 19 of expander 14 protrudes outwardly from base material 55, to facilitate mating with a nut to complete anchoring of fixture 43 to base material 55. In the embodiment of Figs. 19a and 19b, self-drilling anchor 5, after having drilled a hole within base material 55, is removed from the hole and then positioned in an inverted orientation within the hole to accommodate female expander 16. Female expander 16 is subsequently hammered into the inverted self- drilling anchor 5, to apply force F against base material 55. By inverting self- drilling anchor 5, its flat distal end 8 will be in abutting and non-penetrating relation with the adjoining surface of the bore, thereby inducing higher reactive forces.

It will be appreciated that an anchor inverting operation may be performed in conjunction with other expanders described herein.

Fig. 2b illustrates a self-drilling anchor 15 similar to self-drilling anchor 5, but with a radially extending shoulder portion 9. Radially extending portion 9 is shown to have a flat shape that is substantially perpendicular to, and radially extends from the proximal end 8 of, main body 3; however, radially extending portion 9 may be configured in other ways, such as with a conical, proximally extending protrusion.

Figs. 4a, 4b and 4c illustrate expanders 14, 16 and 17, respectively, which are engageable with self- drilling anchor 15 so as to induce expansion of the latter, as described hereinabove.

Referring now to Fig. 22, the provision of self-drilling anchor 15 advantageously facilitates the securing of a fixture 43, such as a plate, to a solid base material 55 without need of other fasteners such as a nut or screw. While nail-like expander 17 is being driven into self-drilling anchor 15, as shown in Fig. 20a, a reactive force is produced between the shoulder shape portion 9 of self-drilling anchor 15 and the fixture 43 being fastened, to reduce or to completely avoid occurrence of play between fixture 43 and base material 55. Head portion 23, after expander 17 has been completely driven into the interior of self-drilling anchor 15 as shown in Fig. 20b, presses onto shoulder shape portion 9.

Another advantageous use of the shoulder shape portion 9 of self-drilling anchor 15 is anchorage within a hollow base material 57, such as a concrete block or plasterboard, as shown in Fig. 23. In order to avoid entry of the majority of, or the entire, self- drilling anchor 15 during a drilling or expansion operation into the hollow interior 59 of base material 57 and the resulting reduction in gripping force, shoulder shape portion 9 is urged to be in abutting relation with outer face 58 of base material 57 through which the reactive force is transmitted.

Fig. 6 illustrates another embodiment of a male expander 21 which is provided with a pointed distal portion 26. The female and naiHike expanders may also be configured with pointed distal portion 26.

In another embodiment, the non-drilling anchor 1 shown in Fig. la and formed without any cutting teeth may be anchored within a drilled hole according to the teachings of the invention, i.e. by means of an expander driven into its proximal end. By virtue of its continuous and uninterrupted tubular main body 2, which may be C-shaped, the anchor is substantially uniformly expandable to reduce or eliminate stress concentrations in the base material adjoining the hole in which it has become anchored, and additionally may be more simply and inexpensively manufactured than prior art anchors.

A non-drilling anchor 12 shown in Fig. 2a is provided with a radially extending portion 9, and is afforded the same advantages as described above with respect to a self-drilling anchor.

The non-drilling anchor may be expanded by any of the expanders described above, or by any other desired expander. For example, Fig. 3e illustrates another embodiment of an expander 63, which is an external female expander configured with two portions of different widths. Distal portion 65 adapted to be inserted within the interior of non-drilling anchor 1 for purposes of expansion has a smaller diameter than proximal portion 66, which protrudes from solid base material 55. A bore with internal threading 22 is formed within proximal portion 66, to facilitate connection of a threaded elongated element, such as a pipe, thereto. Proximal portion 66 is formed with a socket 68 that is disposed proximally relative to threading 22 and defines an annular proximal surface 67. Annular surface 67 is used for transmitting a hammering force, and socket 68 is used for guiding the driving tool while applying the hammering force onto surface 67.

Reference is now made to the configuration of the driving tool.

Fig. 7 illustrates a driving tool 40 that is connectable at its proximal end to a power tool, such as a rotary hammer or hammer drill, and at its distal end to a self-drilling anchor, such as self-drilling anchor 5. Driving tool 40 has a cylindrical guiding portion 44 that extends distally from, and is coaxial with, shank 45. The outer diameter of guiding portion 44 is substantially equal to the inner diameter of self-drilling anchor 5, thus preventing radial movement of the self- drilling anchor 5 with respect to driving tool 40. A spline 42, which is insertable into slot 4 of the self-drilling anchor 5 in order to transmit torque thereto, protrudes radially from the outer surface of guiding portion 44 and distally from a shank end surface 46 surrounding guiding portion 44 to an intermediate region of guiding portion 44. A mating element 49 having a diameter smaller than, or equal to, and extending distally from, guiding portion 44 may be used in the hammering mode. Fig. 8 illustrates a cross section of self-drilling anchor 5 and driving tool 40 when coupled together. Driving tool 40 has an intermediate annular shank end hammering surface 46 (also shown in Fig. 7), e.g. planar, by which a hammering action shown in Fig. 15 and step 52 of Fig. 26 applied from the power tool is transmitted through shank 45 of driving tool 40 to the annular proximal end 8 of self-drilling anchor 5 which is in abutting relation with shank end surface 46. Shank 45 of driving tool 40 is adapted to be coupled to the chuck of the power tool, and may be configured with a non-circular cross-section to prevent slippage during rotation.

Fig. 21 illustrates slot 4 of self- drilling anchor 5 when spline 42 of driving tool 40 is fit therewithin. Slot 4 is sufficiently wide to accommodate a spline 42 of a minimum width that will be ensured of retaining its structural integrity when transmitting torque to self- drilling anchor 5. For example, the width of the spline ranges from 1-5 mm, and preferably 2.5-3.5 mm, for a self-drilling anchor having an outer diameter of 8 mm.

A self-drilling anchor may be configured with one or more differently shaped slots.

Fig. 5a illustrates a self-drilling anchor 25 formed with a slotted portion 24 which longitudinally extends from proximal end 8 to an intermediate region of main body 3 that is positioned proximally to teeth 7. Self- drilling anchor 25 may also be provided with a shoulder shape portion 9 shown in Fig. 2b.

Fig. 5b illustrates a self- drilling anchor 35 with a proximal slot 37 that is wider than a distal slot 38 collinear therewith. Proximal slot 37 is adapted to receive the spline, while the narrower distal slot 38 is used for debris removal. Fig. 5c illustrates a self- drilling anchor 54 similar to self-drilling anchor 35, but with a thin-walled portion 53 formed integrally with main body 3. Distal slot 38' longitudinally extending from, and of a different width than, proximal slot 37, e.g. wider than proximal slot 37 as illustrrated, is recessed in main body 3 to form thin-walled portion 53. Thin-walled portion 53 increases the rigidity of self- drilling anchor 54 when being drilled within the base material, yet constitutes a frangible region which, when broken when the expander is introduced into the interior 10 of self-drilling anchor 54, enables expansion of main body 3.

Fig. 5d illustrates a self-drilling anchor 69 similar to self-drilling anchor 35, but with a plurality of circumferentially spaced protrusions 71 radially protruding from the vicinity of proximal end 8. Protrusions 71 apply a force on the peripheral wall of a bored hole when self-drilling anchor 69 is fully inserted therewithin, providing the anchor with self-locking characteristics to prevent removal from the drilled hole when the driving tool is disengaged therefrom.

It will be appreciated that other anchors described herein may also be provided with protrusions 71.

Driving tool 40 may also be used for driving self-drilling anchor 15 shown in Fig. 2b with a shoulder shape portion 9.

Fig. 9 illustrates a driving tool 41 similar to driving tool 40 of Fig. 7, but provided with two, or any other number of, splines 42a and 42b. A self-drilling anchor 36 with two or more slots 4 and 37 accommodates driving tool 41. Self-drilling anchor 36 may also be provided with a shoulder shape portion.

Fig. 10 illustrates another combination of the driving tool and self-drilling anchor. In this embodiment, driving tool 56 has an interface portion 48, e.g. with at least one planar element such as defining a hexagonal member, radially protruding from mating element 49, for being received in a complementary proximal socket 51 of self-drilling anchor 39, thus enabling the rotational power to be transmitted to self-drilling anchor 39. A socket equipped self-drilling anchor may also be provided with a shoulder shape portion.

Expanders 14, 16 and 17 shown in Figs. 11a, lib and 11c, respectively, may also be formed with a proximal socket 21. Upon completion of a drilling operation, mating element 49 of driving tool 40 is coupled with complementary socket 21 of a corresponding expander, for use in a hammering operation. Driving tool 40 linearly drives the coupled expander by hammering upon the inner or outer surface of socket 21.

Driving tool 70 shown in Fig. 12 has two mating elements 72 and 73, in order to be coupled to a male expander or alternatively to a similarly sized female expander. The distal mating element 73 is used for coupling with male expander 14, as shown in Fig. 13a. Distal mating element 73 is received in the socket 21 of male expander 14, for transmitting the hammering power. The proximal mating element 72 is used for coupling with female expander 16, as shown in Fig. 13b.

Proximal mating element 72 has a larger diameter than distal mating element 73. The distal surface 76 of distal mating element 73 is configured to be in abutting relation with the distal wall of the socket 21 of male expander 14, in order to transmit the hammering power. Likewise annular surface 78 of guiding portion 44 surrounding proximal mating element 72 is configured to be positioned in abutting relation with the annular proximal end 27 of female expander 16, in order to transmit the hammering power. Proximal mating element 72 is sized to be sufficiently short so that annular surface 79 surrounding distal mating element 73 will be spaced from internal threading 22 of female expander 16, in order to prevent damage thereto. Driving tool 80 shown in Fig. 14 has an external threaded portion 83 distally extending from guiding portion 44, for threaded engagement with internal threading 22 of female expander 16.

Fig. 28 illustrates a driving tool 120 engageable with external female expander 63, also shown in Fig. 3e. Driving tool 120 has a proximal coupling portion 126 for coupling with the power tool, a bearing portion 128, e.g. of a larger diameter than coupling portion 126 for engagement with proximal surface 67 of expander 63, portion 123 of a smaller diameter than bearing portion 128, guiding portion 131 extending distally from, and of a smaller diameter than, portion 123. Guiding portion 131 is provided with a spline 133 which is engageable with the slot of a self-drilling anchor, for transmitting torque prior to introduction of expander 63 within the interior of the self-drilling anchor. A distal mating element 137 of a slightly smaller diameter than guiding portion 131 is used to couple with a complementary socket of a different expander, for use in a hammering operation. In this embodiment, the hammering action is effected proximally to spline 133.

Fig. 27 illustrates a self-drilling anchor 115 with a tubular, C-shaped main body 113 defining a single slot 114, and a single circumferentially extending cutting surface 117 formed at the distal end of main body 113. Annular cutting surface 117 is oblique with respect to a plane perpendicular to longitudinal axis 119 and coinciding with distal edge 118 of main body 113 constituting the cutting edge. Cutting surface 117 may extend from said plane inwardly towards axis 119, or alternatively outwardly therefrom.

Figs. 24 and 25 illustrate a self-drilling anchor 95 according to another embodiment of the invention. Self-drilling anchor 95 comprises a main tubular body 93 formed with a longitudinal slot 94, and a plurality of longitudinally spaced, annular gripping elements 97 radially extending from main body 93. Each gripping element 97 has a curved surface 101 that extends proximally outwardly from the surface of main body 93, at an acute angle with respect to the longitudinal axis 107 of self-drilling anchor 95, and a proximal end surface 103 that is substantially perpendicular to longitudinal axis 107, for maximizing the gripping force applied to the base material in which self-drilling anchor 95 is embedded.

As can be appreciated from the foregoing description, the anchor of the present invention can be manufactured more economically and installed quicker than prior art anchors, while being able to mitigate or completely eliminate stress concentration in the base material within which it has been embedded.

While some embodiments of the invention have been described by way of illustration, it will be apparent that the invention can be carried out with many modifications, variations and adaptations, and with the use of numerous equivalents or alternative solutions that are within the scope of persons skilled in the art, without exceeding the scope of the claims.

Claims

1. A system for installing an anchor in a base material, comprising:

a) an anchor positionable within a hole drilled in a base material and having a tubular main body with a hollow annular interior, a proximal end defining an annular aperture in communication with said hollow interior, and a longitudinal slot formed in said main body; and b) an expander configured with a portion having a larger outer diameter than the inner diameter of said hollow interior,

wherein said main body has a continuous and uninterrupted outer surface, with the exception of said longitudinal slot, in both a rest condition and an expanded condition,

wherein said expander is linearly drivable through said proximal end of said anchor into said hollow interior to induce said anchor to expand at a given circumferential region thereof while minimizing stress concentrations in, and being anchored to, the base material, by virtue of said uninterrupted outer surface.

2. The system according to claim 1, wherein the anchor is configured with a portion that radially extends from, the proximal end of the main body, said radially extending portion being positionable in abutting relation with an outer face of the base material or of a fixture fastenable to the base material, through which a reactive force is transmittable.

3. The system according to claim 1, further comprising a dedicated driving tool for linearly driving the expander into the hollow interior of the anchor.

4. The system according to claim 3, wherein the driving tool has a proximal end which is engageable with a power tool and a portion which is engageable with the expander.

5. The system according to claim 4, wherein the anchor is a self-drilling anchor configured with one or more cutting edges formed at a distal end of the main body thereof, for use in drilling a hole in the base material.

6. The system according to claim 5, wherein the driving tool has a shank that extends from the proximal end to a distal end thereof, and a cylindrical guiding portion insertable within the interior of the self-drilling anchor that extends distally from, and is coaxial with, said shank, for preventing radial movement of the self-drilling anchor with respect to the driving tool.

7. The system according to claim 6, wherein one or more splines extend radially from an outer surface of the guiding portion and each of which is engageable with a corresponding slot of the self-drilling anchor.

8. The system according to claim 7, wherein the spline is of a minimum width that will be assured of retaining its structural integrity when transmitting torque from the driving tool to the self- drilling anchor and the corresponding slot is sized to receive the spline.

9. The system according to claim 1, wherein the anchor is a non- drilling anchor.

10. The system according to claim 2, wherein the radially extending portion is of a shoulder shape that is substantially perpendicular to the proximal end of the main body of the anchor.

11. A self-drilling anchor, comprising:

a) a tubular main body with a hollow annular interior; b) a proximal end defining an annular aperture in communication with said hollow interior! and

c) a longitudinal slot formed in said main body; and

d) one or more cutting edges for drilling a hole in a base material formed at a distal end of said main body,

wherein an expander configured with a portion having a larger outer diameter than the inner diameter of said hollow interior is linearly drivable through said proximal end of said anchor into said hollow interior to induce said anchor to expand at a given circumferential region thereof while minimizing stress concentrations in, and being anchored to, the base material, by virtue of said uninterrupted outer surface.

12. The self-drilling anchor according to claim 11, further comprising a plurality of longitudinally spaced, annular gripping elements radially extending from the main body.

13. A driving tool for facilitating installation of an anchor in a base material, comprising:

a) a proximal end engageable with a power tool; and

b) a mating element engageable with an expander configured to expand an anchor positioned within a hole which has been drilled within a base material, for transmitting to said expander a hammering action generated by said power tool.

14. The driving tool according to claim 13, wherein the mating element is coupleable with a complementary socket formed in the expander.

15. The driving tool according to claim 13, further comprising a spline engageable with a slot formed in the anchor which is a self-drilling anchor, for transmitting to said self-drilling anchor a torque generated by the power tool.

16. The driving tool according to claim 15, further comprising a shank that longitudinally extends from the proximal end, and a cylindrical guiding portion insertable within an interior of the self-drilling anchor that extends distally from, and is coaxial with, said shank, for preventing radial movement of the self- drilling anchor with respect to the driving tool.

17. The driving tool according to claim 16, which is further configured with an annular shank end surface surrounding the guiding portion, for engaging a proximal end of the anchor and for transmitting thereto a hammering action generated by the power tool.

18. The driving tool according to claim 13, which is further configured with a shank end surface for engaging a proximal end of the anchor and for transmitting thereto a hammering action generated by the power tool.

19. A method for installing an anchor in a base material, comprising the steps of

a) positioning within a hole drilled in a base material, an anchor configured with a tubular main body having a continuous and uninterrupted outer surface with the exception of a longitudinal slot, a hollow annular interior, and a proximal end defining an annular aperture in communication with said hollow interior;

b) partially inserting an expander configured with a portion having a larger outer diameter than the inner diameter of said hollow interior into said proximal end of said anchor; and c) linearly driving said expander into said hollow interior to induce said anchor to expand while being anchored within the base material.

20. The method according to claim 19, wherein the anchor is a self-drilling anchor configured with one or more cutting edges that are formed at a distal end of the main body thereof, for use in drilling the hole in the base material.

21. The method according to claim 20, wherein the self-drilling anchor is linearly driven within the base material to a depth less than the length of the main body prior to performing a drilling operation.

22. The method according to claim 21, wherein the expander is partially inserted into the proximal end of the anchor following performance of the drilling operation and is then linearly driven to induce expansion of the anchor.

23. The method according to claim 19, wherein the anchor is inverted prior to being expanded.