HK1156678B - Radially expanding bolt assembly - Google Patents

Description

Radial expansion bolt

Cross Reference to Related Applications

The present application claims U.S. provisional patent application serial No.61/075,791 filed on 26/6/2008 and U.S. non-provisional patent application serial No.12/425,518 filed on 17/4/2009. The subject matter of the aforementioned U.S. provisional and non-provisional patent applications is further expressly incorporated herein by reference.

Technical Field

The present invention relates to bolt assemblies, and in particular to radially expanding bolt assemblies.

Background

Radial expansion bolt assemblies are known in the art. Known radially expandable bolt assemblies include an outer tubular expandable member formed as a sleeve having an inner tapered portion and a cooperating inner expandable member formed as an inner stud having an outer tapered portion that mates with the tapered portion of the sleeve. The outer sleeve is inserted in a bore of an object to be tensioned, for example two adjoining flanges connected to each other. The inner stud is then inserted into the outer sleeve and pulled by external means to force the tapered section to slide over the other tapered section, thus expanding the outer sleeve.

Now, a hydraulic tool or a plurality of screw jacks are used as external tools for applying tensile loads to the radial expansion bolt assembly. It is believed that existing radial expansion bolt assemblies can be further improved.

Disclosure of Invention

It is therefore an object of the present invention to provide a radial expansion bolt assembly which is a further improvement over prior art assemblies.

These objects, together with others which will become apparent hereinafter, are a feature of the present invention which, in brief, is: a radially expanding bolt assembly, comprising: a hollow member insertable into a bore of an object, having an axis and being radially expandable, and having an inner surface with at least one inner surface portion that is tapered; an expansion member insertable into the hollow member and having an outer surface with at least one tapered outer surface portion cooperating with the tapered inner surface portion of the hollow member, the expansion member having two opposing axial ends, each of the axial ends being engageable with an additional member configured to move the expansion member in opposing axial directions for tightening and loosening a bolt assembly; and a washer disposable between the object and an additional component at one of the axial ends such that the additional component moves the expansion member in one axial direction and expands the hollow member as a result of the tapered inner surface portion and the tapered outer surface portion cooperating to clamp the hollow member in the hole of the object, while the other additional component moves the expansion member in an opposite axial direction and the tapered inner surface portion and the tapered outer surface portion disengage from each other such that the hollow member contracts and the radially expanding bolt assembly is detachable from the hole of the object.

Another feature of the present invention, briefly stated, is that: the expansion member has engagement structures disposed on the opposite axial ends and engageable by additional members.

Yet another feature of the present invention is that the washer is non-rotatably connected to one axial end of the hollow member; and means are provided for non-rotatably connecting the washer with the one axial end of the hollow member.

A further feature of the invention is that the washer has means for engagement by a tool for rotating the one additional component and the means absorbs the reaction force generated when the tool applies a force to the one additional component.

Yet another feature of the present invention is that the hollow member at the opposite axial end has a radially projecting portion.

A further feature of the invention is that the projection is provided with means for engagement by a tool which absorbs the reaction forces generated when the tool applies a force to the other additional member to move the expansion member in the opposite axial direction.

The novel features believed characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

Drawings

FIG. 1 is a cross-sectional view showing a radial expansion bolt assembly according to the present invention mated with an object to which it is applied; and

fig. 2 is a perspective view of a radial expansion bolt assembly according to the present invention.

Detailed Description

The radial expansion bolt assembly of the invention comprises an outer hollow tubular member formed as a sleeve (1). The sleeve (1) has an outer cylindrical surface and, in addition, an inner surface comprising at least one tapered portion (2). The sleeve (1) has an axis (2) and two axial ends (3, 4). The axial end (3) of the sleeve (1) is provided with an engagement structure (5), for example formed by an axially extending key, or a hexagonal flat, or star-shaped surface, or other polygonal structure; while the opposite axial end (4), which is formed as a radially projecting flange, also has an engagement structure (6), which can, for example, also be formed by an axially extending key, or a hexagonal plane, or a star-shaped surface, or other polygonal structure; the purpose of which will be explained below.

The radial expansion bolt assembly also has an expansion member provided with an inner stud (7). The inner stud (7) has two opposite axial ends (8, 9) each having an engagement formation, e.g. a thread (10, 11), the purpose of which will be explained below. The stud (7) has an outer surface with at least one portion (12) of substantial taper corresponding to the tapered portion (2) of the inner surface of the sleeve (1).

The radial expansion bolt according to the invention is further provided with a washer (designated with reference numeral 13). The washer (13) has an inner surface provided with an inner key, or hexagonal flat, or other polygonal structure (14) capable of engaging with the outer polygonal structure of the sleeve (1) in order to connect the washer (13) and the sleeve (1) non-rotatable about the axis (a). The washer (13) also has external engagement formations formed, for example, by external axially extending keys, or hexagonal flats, or star-shaped surfaces, or other polygonal formations, to be engaged by a tool for tightening or loosening the bolt assembly.

The stepped nut (16) has a portion which can be inserted into the opening of the washer (13) and has an internal thread (17) which can be engaged with the external thread of the stud bolt (7). The nut (16) also has an exterior provided with a plurality of axially extending splines, or hexagonal flats, or star-shaped surfaces, or other polygonal configurations (18). The other nut (19) has a portion which can be inserted into the other end opening of the sleeve (1) and has an internal thread (20) which can be engaged with the external thread of the other end of the stud bolt (7). The nut (19) also has an outer portion provided with a plurality of axially extending splines, or hexagonal flats, or star-shaped surfaces, or other polygonal configurations (21).

The casing (1) is radially expandable. This can be achieved by providing the sleeve (1) with a thin, stretchable wall, by providing the wall with longitudinal grooves (22) or the like.

The radial expansion bolt assembly according to the present invention operates in the following manner:

the outer sleeve (1) is first passed through the inner bore (23, 24) of an object consisting of two flanges aligned and fixed to each other. The washer (13) is then mounted on the right axial end (3) of the outer sleeve (1) and its inner polygonal formation engages with the outer polygonal formation of the sleeve (1). A stud (7) is introduced into the interior of the sleeve (1), and a nut (16) is screwed onto the right axial end of the stud (7). A tool such as a torque wrench is applied to the expansion bolt assembly. Specifically, the force is applied by a rotating portion of the tool engaging a polygonal formation (18) of the nut (16), while a reaction absorbing portion of the tool, e.g., a stationary seizure component, engages a polygonal formation (15) of the washer (13).

The inner stud is pulled to the right in fig. 1 when the nut (16) is turned by means of a tool absorbing the reaction, via the washer (13). Since the tapered portion of the outer surface of the stud (7) cooperates with the tapered portion (2) of the inner surface of the outer sleeve (1), the sleeve (1) expands radially outwardly upon axial movement thereof. By radial movement of the stem (7), the flanges (25, 26) of the object are aligned with each other and clamped axially between the washer (13) and the flange (14), and the radially expandable sleeve (1) is radially clamped in the hole (23, 24) of the object and the bolt assembly is tightened in the object.

To release the radially expanding bolt assembly from the object, a nut (19) is threaded on the left axial end of the stud (7) and turned by a part of the tool applying the force, while another part of the tool absorbing the reaction and being fixed engages the polygonal structure of the flange (4) of the casing (1). The nut (16) is unscrewed from the right axial end of the stud bolt (7). When the nut (19) is turned, the stud is pulled in the opposite direction, the tapered portion of the outer surface of the stud (7) disengages from the tapered portion of the inner surface of the sleeve (1) so as to relieve the radially outward pressure on the upper stud (7) of the sleeve (1). The outer diameter of the outer sleeve (1) is reduced and detached from the inner wall of the bore (23, 24) of the object (25, 26). The inventive assembly can be pulled through the holes (23, 24) to the left and detached from the object (25, 26).

It will be appreciated that each of the components described above (or two or more together) may also be usefully applied to other types of configurations than those described.

While the invention has been illustrated and described as embodied in a radially expanding bolt assembly, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of this invention.

The claims as new and as protected by letters patent are set forth in the appended claims.

Claims (10)

1. A radially expanding bolt assembly, comprising: a hollow member insertable into a bore of an object, having an axis and being radially expandable, and having an inner surface with at least one inner surface portion that is tapered; an expansion member insertable into the hollow member and having an outer surface with at least one tapered outer surface portion cooperating with the tapered inner surface portion of the hollow member, the expansion member having two opposing axial ends, each of the axial ends being engageable with an additional member configured to move the expansion member in opposing axial directions for tightening and loosening a bolt assembly, respectively; and a washer disposable between the object and one of the additional components at one of the axial ends such that the one additional component moves the expansion component in one axial direction and expands the hollow component as a result of the tapered inner surface portion and the tapered outer surface portion cooperating to clamp the hollow component in the hole of the object, while the other additional component moves the expansion component in an opposite axial direction and the tapered inner surface portion and the tapered outer surface portion disengage from each other such that the hollow component contracts and the radially expanding bolt assembly is detachable from the hole of the object.

2. A radially expanding bolt assembly as defined in claim 1, wherein said expanding member has engagement formations provided on said opposite axial ends and engageable by additional members.

3. A radially expanding bolt assembly as defined in claim 2, wherein said engagement formations on said opposite axial ends of said expanding member comprise threads.

4. A radially expanding bolt assembly as defined in claim 1, wherein said washer is non-rotatably connected with one axial end of said hollow member; and, said radially expanding bolt assembly further comprises means for non-rotatably connecting said washer with said one axial end of said hollow member.

5. A radially expanding bolt assembly as defined in claim 4, wherein said means for non-rotatably connecting said washer with said one axial end of said hollow member comprises a polygonal configuration.

6. A radially expanding bolt assembly as defined in claim 1, wherein said washer has means for engagement by a tool for turning said one additional member and said means absorbs a reaction force generated when a force is applied to said one additional member by said tool.

7. A radially expanding bolt assembly as defined in claim 6, wherein said means for engaging by said tool comprises a polygonal configuration.

8. A radially expanding bolt assembly as defined in claim 1, wherein said hollow member at the other of said opposite axial ends has a radially projecting portion.

9. A radially expanding bolt assembly as defined in claim 8, wherein said projecting portion is provided with means for engagement by a tool which absorbs the reaction forces generated when said tool applies a force to said other additional member to move said expanding member in the opposite axial direction.

10. A radially expanding bolt assembly as defined in claim 3, wherein said additional component is a threaded nut.