GB2304850A - Expanding anchor bolt - Google Patents

Abstract

Four elongate segments (1) are positionable side-by-side to form a cylindrical body, and have their ends (2) located in a bush (4) and their ends (5) moved apart by a cone or pyramid nut (9) drawn between them by a screw (not shown) extending through an opening (12) in the bush (4), grooves (3) in the segments (1) facilitating the splaying of the segment ends (5). The nut (9) has lugs (8) which are retained in spaces formed by lateral projections (6) of the segment ends (5).

Description

EXPANSION SECURING BOLT The invention relates to a new attachment bolt, the improvements to which represent an evident novelty in this type of component, being designed to offer maximum attachment surface on the walls of the hole where it is installed, to ensure a hermetic surface mooring and prevent the possible release of material at points where protrusions such as cramps or the like are supported. To remove this securing bolt, all the material in which it is installed would have to be broken: this is highly improbable given the limited weight it must bear. Thus manufacture can be at a most accessible cost, given the simplicity of its components and mechanisms. Its structural and design features differ significantly from those of existing bolts, dowels and other devices for these purposes.

In essence, the improved attachment bolt which is the subject of the invention consists of four or more elements with an outwardly arch-shaped form, comprising sectors, so that all the parts coupled head-to-head adopt the cylindrical shape of the bolt. Its cylindrical design, without protrusions, offers a contact surface inside the hole where it is to be used right around the bolt itself. In this way, when deformed to take on a slightly tapered cone shape thanks to the movement of the nut inside the bolt' s radial elements, the entire external surface of the bolt presses on the inside walls of the hole where it is fitted, to provide great mechanical strength, security and stability under any pressure and external weight, thereby improving considerably on existing bolts.

For a better understanding of the general features described above, drawings are included showing in graphic form a practical design of the improved multiple expansion radial securing bolt which is the subject of the invention: it is hereby recorded that, given the overridingly informative nature of the drawings in question, the figures should be examined with the very broadest criteria and without any limitation whatsoever.

The figures in the attached drawings show the following: Figure 1. A front view in a longitudinal projection of the inside of one of the four arch elements constituting the surface of the bolt outline: on the side corresponding to the interior of the bolt when inserted in its housing, lateral expanded sections are seen forrning a blade-like element to retain the nut and prevent it from turning. On the inside face of this blade shape, there is a ramp for the pressure from the nut which expands the bolt, and grooves for the pressure spring while, at the other end, there is a groove for fitting inside the bushing located on the exterior.

Figure 2. A lengthwise cross-section of the element in figure 1 showing the internal ramp for the expansion of the bolt and the external grooves on its two ends for the spring and assembly housing.

Figure 3. A view of the arch-shape profile of the bolt component as shown in figure 1, from the end where it is fitted inside the hole or cavity for attachment.

Figure 4. A view of the arch-shaped profile of the element in figure 1, from the back end, revealing clearly the arched design.

Figure 5. A front view of the movable nut that expands the bolt, which nut is held from the end and housed inside between the four parts that form the outline of the bolt.

Figure 6. An elevation view of the nut in figure 5, showing the base, the protruding side pivots that fit into the matching triangular cavities between the adjacent arch-shaped components, with their pyramid or conical shape, enabling them by the traction of a screw from the outside to move inside the arch-shaped elements to expand the bolt.

Figure 7. A cross-section of the nut in figures 5 and 6.

Figure 8. A front view of the outer housing which, at one end, holds the arch shaped components forming the body of the bolt.

Figure 9. A cross-section of the housing in figure 8.

Figure 10. A profile view of the retaining spring for the arch-shaped elements forming the body of the bolt.

Figure 11. A general lengthwise projection of the improved securing bolt, fully assembled and ready for use.

Figure 12. A lengthwise cross-section of figure 11, showing the arrangement of the mooring nut that expands the bolt under traction from an outside screw, which acts as the hanger.

In all cases with reference to the attached drawings, it is to be noted that the various figures shown there include numerical references connected with the following description of the features and use, so as to facilitate their immediate location. The arch-shaped segments 1 fitted together side-by-side form the body of the bolt. The front of these segments forms the blade 2 which is limited by the transverse external groove 3 that fits into the housing or bushing 4 for the axial screw incorporated from the outside and which secures the bolt.

A blade element 5 is at the end of the segments 1 for fitting into the mooring cavity.

The end of element 5 has clamp-like lateral protrusions 6 forming cavities 7 between two adjacent arch-shaped segments. Said cavities are defined by substantially triangular edges, to house the protrusions 8 forming part of the angles or corners on the nut 9, the outside of which takes on a cut-off cone or pyramid shape. Nut 9 fits between the blades 5 forming part of the segments 1 that go to make up the bolt. The external form of the bolt is cylindrical, fitting perfectly into the hole where it is to be housed and locked, providing contact surface right around its periphery so that, when the bolt expands, it offers a complete and total lock into the opening or cavity where it is applied.

Between the rear end blade 5 and the central body of the segments 1, there is a groove 10 in the outside surface to house the two-spiral spring 11 that acts as a retention to keep the bolt in place.

The housing or bushing 4 has a central opening 12 through it for the assembly screw, added from the exterior. The end of assembly screw screws into the threaded opening 13 of the nut 9 on which it exerts a traction force so that, on entering the segments 1, the oblique shape 14 of the inside of the blades 5 causes said segments 1 to widen accordingly, expanding the spring 11 so as to provide a very good attachment.

It is considered that all the parts of this improved radial multiple-expansion securing bolt which is the subject of this invention have been broadly described and it remains only to be pointed out that the different parts may be manufactured in a variety of materials, sizes and shapes, while constructive amendments may be made to its design as use would suggest.

Claims (13)

1. An improved radial multiple-expansion securing bolt for attaching to a cavity wherein, at least four arch-shaped segments with a flat external surface and straight edges are fitted side-by-side to form the general body of said bolt, each of the segments comprising a blade on its front end which operably fits into a bushing, wherein said front ends comprise an external off-set or groove enabling slight rocking against the housing, said housing having a through opening for a screw which screw is insertable from the outside to effect the attachment to the cavity by expanding the rear end of the bolt once housed inside the cavity where it is to be secured.

2. An improved radial multiple-expansion securing bolt as set forth in the previous claim wherein the expansion element coupled between the segments at the rear is externally of a cut-off conical or pyramid shape with lugs that protrude from its angles, enabling the part to be housed and secured between the end blades of the segments which have angled narrowed sections towards the end, with clamp-like broader sections at the ends themselves which fit into the largely triangular cavities of the adjacent blades.

3. The bolt of claim 1 or 2 wherein the assembly as a whole is fitted under the pressure of a two-spiral spring housed in an external channel or groove in the segments.

4. The bolt of claim 1, 2 or 3, wherein the expansion element has a central threaded cavity, acting as a nut to which the screw is threaded when inserted from outside to expand the bolt by displacing said nut inside the bolt between its segments.

5. An expansion bolt for attaching to a cavity comprising at least four elongate segments comprising an inner arch shape region and outer flat surface region, the segments being positionable side-by-side to form a substantially cylindrical bolt body, the segments comprising a first end blade positionable adjacent the opening of the cavity in use and each having an outer groove, a housing for engaging the first end blades having a through bore for a screw, and means for cooperating with a screw to effect expansion of the bolt in use, wherein the grooves in the first end blades enable slight pivotal motion of the segments with respect to the housing thereby to enable attachment of the bolt to the cavity.

6. A bolt according to claim 5 wherein the housing comprises a circumferential rim which is positioned adjacent the grooves in the first end blades in use.

7. A bolt according to claim 5 or 6 wherein the expansion means comprises an expansion element or nut positionable at the ends of the segments remote from the housing.

8. A bolt according to claim 5, 6 or 7 wherein the segments each comprise a second end blade remote from the first end blade which second end blades comprise means for clamping to the expansion element.

9. A bolt according to the preceding claim 8 wherein the clamping means comprise lateral protrusions and the expansion element comprises lugs for engagement therewith.

10. A bolt according to claim 9 wherein the expansion element comprises a portion which is frustoconical or pyramidal in shape.

11. A bolt according to any of claims 5 to 10 wherein the segments comprise a second groove for receiving a resilient retaining member.

12. A bolt according to the preceding claim wherein the retaining member comprises a helical spring.

13. A bolt substantially as described herein and as shown in the accompanying drawings.