TECHNICAL AREA

The present invention relates to an attachment device and in particular an

attachment device to be used with posts, such as railing posts, balcony posts and the like.

BACKGROUND OF INVENTION

For many years metal posts have been used for providing railings for balconies, for stairways and the like. A preferred metal has been aluminium and in particular for some do it yourself systems.

A very important aspect with such a system is the attachment of the posts to a fixed foundation, like a balcony floor. A conventional attachment member is then a holder which is bolted to the foundation. The holder has a recess or connection into which an end of a post can be inserted and secured by a locking member, where the recess and the post have complementary shapes as seen in a cross-sectional view of the post in order to minimize the play between the holder and the post, possibly creating a friction force between the holder and the post.

However, since aluminium is a rather soft material an since lateral forces on the free end of the post may be considerable if a person, or several persons, lean against the railing and thus bending the posts, a play may be created between the holder and the post, in particular since most of the holders do not extend upwards around the posts for more than maximum 100 mm, usually less. The extension upwards is further of minor importance since a bending force on the post will cause a point contact between the upper edge of the holder and the post, which also is a drawback.

There are thus improvements to be made regarding securely attaching posts for balcony railings, stairway railings and the like. BRIEF DESCRIPTION OF INVENTION

The aim of the present invention is to remedy the drawbacks of the state of the art and to provide an attachment device that will securely fix a post to a foundation. This aim is obtained with an attachment device according to the features of the independent patent claim 1.

Preferable embodiments of the present invention form the content of the dependent patent claims.

According to the invention, the attachment device is intended for elongated members like posts provided with a compartment. The compartment could be the interior of a tubular post, but may also be a specially designed compartment in an otherwise solid post.

The attachment device preferably comprises an attachment member arranged to be fixedly attached to a foundation. The foundation could be any stable or robust structure such as a balcony platform, a staircase, a patio or the like where for example posts for railings are attached to minimize the risk of falling off from the foundation.

The attachment device may comprise a threaded pin rotatably attached to said attachment member and may further comprise at least three locking members, each arranged with a passage through which said threaded pin extends and intended to be positioned after each other along said threaded pin.

Preferably said at least three locking members are arranged with contact surfaces having an inclination in relation to a longitudinal axis of said threaded pin. Further, preferably the passage of the locking member farthest from said attachment member is arranged with threads that cooperate with the threads of said threaded pin. Thereby, that locking member may be moved along the threaded pin when they are rotated in relation to each other. Thus, rotation of said threaded pin causes the inclined contact surfaces of said at least three locking members to interact such that said at least three locking members are moved in generally perpendicular directions in relation to said longitudinal axis, each capable of exerting a force on an inner surface of a compartment of a post pushed onto said attachment device. In this manner, the locking members of the attachment device are capable of frictionally locking said post in a very positive and secure manner. Since the locking members are arranged along the threaded pin, the forces from each locking member is distributed along a certain length of the post and not restricted to a limited, or even point, contact surface.

According to a preferred solution, the contact surfaces of an intermediate locking member have converging inclinations. This will give the intermediate locking member a wedge-like appearance when viewed from the side. This design will, together with a choice of inclinations, provide a function that the forces exerted on said inner surface by adjacent locking members have generally opposite direction. This will positively distribute the forces in several directions along the length of the post.

In order to be rotatably arranged to the attachment member, the threaded pin may be arranged with a head at one end, and that said attachment member is arranged with a seat for said head.

In order to provide a positive and firm locking effect of the attachment device, said threaded pin may be arranged with a socket arranged for engagement with a tool for turning said threaded pin. The socket may be of many suitable types adapted for certain tools and tool shapes such as Allen keys, Torx bits, Phillips bits, just to mention a few. In this respect, the socket may be placed in said head. Instead, or in addition, the socket may be arranged at a free end of the threaded pin. These and other aspects of, and advantages with, the present invention will become apparent from the following detailed description of the invention and from the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

In the following detailed description of the invention, reference will be made to the accompanying drawings, of which Fig. 1 is a cross-sectional view of one example of the present invention, and

Fig. 2 is a schematic side view of an alternative of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

On embodiment of the present invention is shown in the drawing. It comprises an attachment member 10, in the embodiment shown as an elongated plate. A number of through-holes 12 are arranged in the attachment member, through which

attachment means (not shown) can extend in order to fixedly attach said attachment member 10 to a foundation. The attachment means could be screws, bolts, threaded pins, just to mention a few alternatives that can be used depending on the structure and material of the foundation.

The attachment member 10 is further arranged with a generally centrally positioned trough-hole or passage 14. Through this central passage 14, a threaded pin 16 extends. A lower end of the threaded pin is arranged with an enlargement or head 18, which head 18 preferably fits into a corresponding seat 20 arranged in the

attachment member around the passage. The head 18 is further preferably arranged with a socket 22 or recess of certain shape in order to interact with an appropriate tool, such as an Allen key or a Torx key, for example.

A first locking member 24 is further comprised in the attachment device. The first locking member is also arranged with a generally central passage 26 through which the threaded pin 16 extends. The first locking member 24 has a shape, as seen perpendicular to a longitudinal axis 36 of the threaded pin 16, that generally

corresponds to an inner compartment 28 of an elongated post 30 such that the inner side walls of the compartment are in contact, or almost in contact, with the outer surface of the first locking member 24 when the post 30 is pushed onto the first locking member 24. The first locking member further has a first end surface 32, which is generally planar and is in contact with an upper surface of the attachment member 10. The first locking member 24 also is arranged with a second end surface 34, which is planar and inclined in relation to the longitudinal axis 36 of the threaded pin 16.

A second locking member 38 is also comprised in the attachment device. It is arranged with a generally centrally positioned passage 40, through which the threaded pin extends 16. The second locking member 38 preferably also has a shape that corresponds to the inner compartment 28 of the post 30 as seen perpendicular to the longitudinal axis 36, however preferably with some play between them. The second locking member 38 further is arranged with a first end surface 42, which is planar and inclined in relation to the longitudinal axis 36. The first end surface 42 of the second locking member 38 has an inclination generally

corresponding to the inclination of the second end surface 34 of the first locking member 24, providing an interaction between the inclined surfaces, as will be described below. The second locking member 38 also is arranged with a second end surface 44, which is planar and inclined in relation to the longitudinal axis 36 of the threaded pin. The inclination of the second end surface 44 is however chosen such that the inclinations of the second locking member are converging, giving the second locking member 38 a wedge-shape as seen in from the side and as shown in the drawings.

A third locking member 46 is also comprised in the attachment device. It is arranged with a generally centrally positioned passage 48, through which the threaded pin 16 extends. The passage 48 of the third locking member is however arranged with threads, which threads are cooperating with the threads of the threaded pin 16. The third locking member 46 preferably also has a shape that corresponds to the inner compartment 28 of the post 30 as seen perpendicular to the longitudinal axis 36, however preferably with some play between them. The third locking member 46 further is arranged with a first end surface 50, which is planar and inclined in relation to the longitudinal axis 36. The first end surface 50 of the third locking member 46 has an inclination generally corresponding to the inclination of the second end surface 44 of the second locking member 38, providing an interaction between the inclined surfaces, as will be described below.

Further, in order that the locking members will not rotate during the use of the device, as will be described below, the attachment member 10 is arranged with a through- going hole 70. The first locking member 24 is arranged with a passage or hole 72, that preferably may be threaded. A suitable pin or bolt 74 is then inserted into the hole 70 and is attached to the first locking member 24. In this manner the first locking member is rotationally locked in relation to the attachment member 10. However, the diameter of the through-going hole 70 is preferably somewhat larger than the pin or bolt 74 so that it is possible for the first locking member 24 to move somewhat as will be described below. In this context, it is to be understood that it could be the other way around such that the pin or bolt 74 is attached to the attachment member and is somewhat smaller in diameter than the hole of the first locking member.

The function of the attachment device is as follows. The device is first pre-assembled, either at a manufacturing site or by a buyer of the device. This is done by entering the threaded pin 16 through the passage 14 of the attachment member 10. Then the first locking member 24 is slid onto the threaded pin 74 through its passage 26 and is oriented such that a pin or bolt associated with either the attachment member or the first locking member fits into the corresponding hole of the other component.

Thereafter also the second attachment member is slid onto the threaded pin through its passage 40. The first and the second locking members are then turned such that their inclined surfaces 34, 42 come in proper contact with each other. After this the third locking member 46 is threaded onto the threaded pin 16 by turning the threaded pin 16 in relation to the third locking member 46. This is preferably done by inserting an appropriate tool into the socket 22 of the head 18. During the turning of the threaded pin 16, the third locking member 46 is aligned such that its inclined surface 50 comes in proper contact with the second inclined surface 44 of the second locking member 38. When the locking members are in contact with each other, but not tightened, they can be inserted into the compartment of the post until an end surface of the post is in contact with the attachment member! 0. Now the threaded pin 16 is rotated further by the tool. This causes the third locking member 46 to be moved towards the second locking member 38 and the second locking member 38 in turn to be moved towards the first locking member 24. Due to the inclined surfaces between the first and the second locking members 24, 38 and the second and the third locking members 38, 46 respectively, the second locking member 38 will be forced in a direction generally perpendicular to the longitudinal axis, whereby a side surface of the second locking member will apply a force on the inner surface of the post as seen by the arrow 60. Also, due to the inclined surfaces between the second and the third locking members 38, 46, the third locking member 46 will also be forced in a direction generally perpendicular to the longitudinal axis as seen by arrow 62. Thus, as the threaded pin is turned, the second and the third locking members 38, 46 in particular, will be forced against the inner surface of the post 30 in generally opposite force directions, thereby providing a frictional lock between the attachment device and the post. Also, due to the inclined surfaces of the first and the second locking members 24, 38, the first locking member 24 will be forced against the inner surface of the post as seen by the arrow 64. Now the attachment member, with the post, may be attached to the foundation by appropriate attachment means.

As an alternative to the above, the threaded pin 16 may additionally, or instead, be provided with a tool socket 76 in the upper, free end thereof. With this possibility, the attachment member 10 with the threaded pin 16, may firstly be attached to the foundation by appropriate attachment means. Then the first and second locking members 24, 38 are slid onto the threaded pin as described above. Thereafter the third locking member 46 is threaded onto the threaded pin by turning the threaded pin with an appropriate tool inserted into the socket 76 at the free end. When the locking members are in contact and aligned, the post 30 is pushed onto the attachment device. Thereafter, the threaded pin 16 is rotated by a tool inserted into the socket 76 at the free end, causing the locking as described above. With this embodiment, either the tool has to have such a length so as to reach into the post in order to turn the threaded pin, or the threaded pin has such a length that its end is readily accessible at the upper end of the post.

In this respect it is to be understood that more than three locking members may be utilized, where the subsequent contact surfaces of the locking members are inclined such that alternating inclinations are arranged, like a zig-zag pattern in order to obtain forces in subsequent opposite directions by the subsequent locking members, as shown schematically in Fig. 2.

It is to be understood that the embodiment described above and shown in the drawings is to be regarded only as a non-limiting example of the invention and that it may be modified in many ways within the scope of the patent claims.