GB2254900A

GB2254900A - Anti-tamper screwed connector

Info

Publication number: GB2254900A
Application number: GB9108287A
Authority: GB
Inventors: Paul Stephen Harrison
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-04-18
Filing date: 1991-04-18
Publication date: 1992-10-21
Also published as: GB9108287D0

Abstract

One or both threaded female and male connectors (1, 2) are provided with a lateral recess (10) for engagement by the end (13) of an operating lever (12), a rotatable shield (4, 5) being secured around the connectors (1, 2) and being provided with a lateral aperture (11) to allow the end (13) of the lever (12) to engage in the recess (10) for rotating the connector (1, 2). <IMAGE>

Description

.ANTI-TAMPER SCREWED CONNECTOR Field of the Invention The present invention relates to an anti-tamper screwed connector.

Background to the Invention Screwed connectors are used throughout the construction industries wherever it is desired that the article under construction should be dis-assembleable. The conventional connectors are generally of the nut-and-bolt type and are secured and released by use of universally available spanners or allen keys. An inherent problem with the freedom of release of the screwed connectors is that joints in a given construction may be undone unintentionally or maliciously by persons with risk of harm to themselves or subsequent users of the construction if the construction then collapses.

Anti-tamper screwed connectors having freely rotating shields to prevent use of spanners or pliers to unscrew the connector are known for use as high-security window locks but are not know for more general construction tasks. These known anti-tamper screwed connectors are un-screwed by use of allen keys.

It is a general objective of the present invention to provide a method and means to antagonise the efforts of vandals to tamper with the connectors securing assembled structures.

Summarv of the Invention According to a first aspect of the present invention there is provided an anti-tamper screwed connector which comprises: a male connector member and a female connector member, each having a longitudinal axis along which the members are threadedly coupled and uncoupled, at least one of the connector members having a lateral recess therein adapted to receive one end of a lever for rotating the connector member about the longitudinal axis of said member; and the connector further comprises one or more shields, each said shield laterally surrounding a respective one of said connector members, the or each said shield being, in use, secured to the respective connector member against uncoupling from the member and being freely relatively rotatable about the longitudinal axis of the member, at least one of the or each said shields having a lateral aperture therein corresponding to the lateral recess of the respective connector member for enabling said lever to be inserted therethrough into engagement with the lateral recess for rotating the shield and connector member together about the longitudinal axis of the said member.

Preferably the or each recess is curved in the plane transverse to the longitudinal axis of the connector member.

Preferably where one or more shields are provided each said recess and corresponding aperture form a continuous curve when the recess and aperture are radially aligned.

Preferably the, in use, accessible portion of each said connector member is of substantially circular cross section having a substantially smooth radially external circumferential surface thereby preventing use of a conventional spanner to turn the connector member about its longitudinal axis.

Preferably the recess is so shallow as to necessitate use of a lever having means to restrain the lever against radial movement relative to the recess when in use.

Preferably said restraining means comprise a tube adapted to fit over the accessible portion of the adaptor member.

The or each shield is preferably provided with a radially inwardly projecting flange to secure the shield against removal from the respective connector member in use.

Where the or each shield is provided with a radially inwardly projecting flange each of said connector members to which a shield is fitted in use is preferably provided with a recess having a shoulder against which the flange may be detained in use such that the shield does not interfere with the making up of the connection.

According to second aspect of the present invention there is provided a male connector member for an anti-tamper screwed connector of the invention, which connector member has a said lateral recess therein and a said shield thereon.

Xccording to a third aspect of the present invention there is provided a female connector member for an anti-tamper screwed connector of the present invention, which connector member has a said lateral recess therein and a said shield thereon.

According to a fourth aspect of the present invention there is provided a method of securing together components of a structure to be assembled comprising the steps of: providing one or more screwed connectors of the present invention; and securing the components of the structure together by use of said one or more connectors.

Brief DescriDtion of the Drawings A preferred embodiment of the present invention will now be more particularly described by way of example and with reference to the accompanying drawings wherein: Figure 1 is a longitudinal sectional view of a preferred embodiment of screwed connector, illustrating the male and female members of the connector in threaded engagement; Figure 2 is a transverse sectional view of the screwed connector of Figure 1 taken along the line II-II in Figure 1.

Figure 3 is a view similar to that of Figure 2, illustrating use of a specialised spanner to rotate the shield and nut together about the shaft of the bolt.

DescriPtion of the Preferred Embodiment Referring to Figure 1, a nut-and-bolt-type anti-tamper screwed connector is shown. The female connector member, or nut, 1 is threaded onto the shank 3 of a male connector member, or bolt, 2.

Each of the nut 1 and head of the bolt 2 are provided with a respective shield 4, 5. The shields 4, 5 are detained by respective flanges 6, 7 thereon seating against respective longitudinally recessed shoulders 15, 16. The shoulders 15, 16 enable the shields 4, 5 to be held in place without frictional engagement of the shields 4, 5 with the structural components secured together by the screwed connector 1, 2.

Each shield 4, 5 is prevented from reversing off the respective connector 1, 2 by provision of a respective resilient rim 8, 9 on the shield 4, 5. The rim 8, 9 is longitudinally outer-most in use, and snaps over the longitudinally outer-most face of the respective connector member 1, 2.

The manner of mounting of each shield 4, 5 to the respective connector member 1, 2 is such that the shield 4, 5 is freely relatively rotatable about the longitudinal axis of the respective connector member 1, 2. Consequently, rotation of the shield 4, 5 about its longitudinal axis will transfer little or no torque to the respective connector member 1, 2.

Access to the female connector member, or nut, 1 for manipulation thereof is obtained by insertion of a specially shaped lever into a lateral recess 10 in the closed second end of the female connector member 1 via a corresponding aperture 11 in the shield 4 thereon.

The recess 10 and aperture 11 are shaped to form a continuous curve as viewed in transverse section (Figure 2). This configuration makes turning of the connector member 1 extremely difficult without a specialised spanner having a key to fit the outline of the composite slot formed by the recess 10 and aperture 11. Furthermore, the shallowness of the composite slot 10, 11 requires that the head of the spanner be constrained against the shield 4.

Referring to Figure 3, a spanner 12 suitably adapted for engaging and rotating the female connector member 1 is illustrated. The head of the spanner 12 has a key 13 curved to fit the recess 10 and aperture 11 and has a tubular extension 14 adapted to fit over the longitudinally outer-most end of the shield 4.

Although both male and female connector members are shown to be shielded in the preferred embodiment this need not be so. If the second of the two connector members is inaccessible in use then there is no need to make provision for preventing its rotation relative to the first member. Where both members are readily accessible to a spanner or like means it may be prudent to provide both connector members with a lateral recess and with a correspondingly apertured shield.

Although in both the above described embodiments the lateral recess in the connector member is illustrated to be provided in the end face of the remote end of the connector member, this recess may alternatively be provided distanced from the end face.

In such case it would be necessary to provide a spanner similar to that shown in Figure 3 but having a retractable equivalent to the key 13 of the spanner 12.

Numerous alternative embodiments of the present invention will be self-evident to the skilled reader.

Claims

CLAIMS:

1. An anti-tamper screwed connector which comprises: a male connector member and a female connector member, each having a longitudinal axis along which the members are threadedly coupled and uncoupled, at least one of the connector members having a lateral recess therein adapted to receive one end of a lever for rotating the connector member about the longitudinal axis of said member; and the connector further comprises one or more shields, each said shield laterally surrounding a respective one of said connector members, the or each said shield being, in use, secured to the respective connector member against uncoupling from the member and being freely relatively rotatable about the longitudinal axis of the member, at least one of the or each said shields having a lateral aperture therein corresponding to the lateral recess of the respective connector member for enabling said lever to be inserted therethrough into engagement with the lateral recess for rotating the shield and connector member together about the longitudinal axis of the said member.

2. A connector as claimed in Claim 1 further characterised in that the or each lateral recess is curved in the plane transverse to the longitudinal axis of the connector member.

3. A connector as claimed in Claim 1 or Claim 2 further characterised in that each said recess and corresponding aperture form a continuous curve when the recess and aperture are radially aligned.

4. A connector as claimed in any preceding Claim further characterised in that the, in use, accessible portion of each said connector member is of substantially circular cross section having a substantially smooth radially external circumferential surface.

5. A connector as claimed in any preceding Claim further characterised in that the recess is so shallow as to necessitate use of a lever having means to restrain the lever against movement relative to the recess when in use.

6. A connector as claimed in Claim 5 further characterised in that said restraining means comprise a tube adapted to fit over the accessible portion of the adaptor member.

7. A connector as claimed in any preceding Claim further characterised in that the or each shield is provided with a radially inwardly projecting flange to secure the shield against removal from the respective connector member in use.

8. A connector as claimed in Claim 7 further characterised in that each of said connector members to which a shield is fitted in use is provided with a longitudinally recessed shoulder against which the flange may be detained in use.

9. A female connector member for a connector as claimed in any preceding Claim, said female connector member having a said lateral recess therein and a said shield thereon.

10. A male connector member for a connector as claimed in any of Claims 1 to 9, said connector member having a said lateral recess therein and a said shield thereon.

11. A method of securing together components of a structure during assembly of the structure comprising the steps of: providing one or more screw connectors as claimed in any of Claims 1 to 8; and securing the components together by use of said one or more connectors.