GB2127890A - Fastening device - Google Patents

Abstract

A fastening device comprises a bolt 20 slidable with clearance 22 in housing 12 for co-operation with a keeper 38. A spring 30 biases the bolt so that a projection 32 can engage automatically in recesses 34, 36 when the bolt is fully retracted or extended thereby positively retaining the bolt in these positions. The bolt is freed for adjustment by pulling the handle to separate the projection from the recess, such separation being possible by virtue of the lateral clearance provided between bolt and housing. Anti-rattle is provided by forming the bolt to engage base 40 of keeper 38 either as shown or by forming a projection on the keeper or on the bolt. <IMAGE>

Description

SPECIFICATION Fastening device This invention relates to a fastening device of the kind comprising a housing for attachment to a first one (e.g. a door) of two relatively movable members and a bolt slidable in the housing for movement between an extended position in which it can engage a keeper associated with the other member (e.g. the door frame) to fasten the two members together and a retracted position in which it is clear of the keeper to permit relative movement between said members.

Such fastening devices are commonly used as door bolts and normally the bolt is rotatable as well as slidable so that the bolt can be turned through 90 into registry with a retaining slot or the like in the housing to prevent unintended sliding of the bolt from the desired position. Thus, with such door bolts, the usual practice is to form the housing with an H-shaped aperture for the purpose of retaining the bolt but this tends to collect dirt and detract from the appearance of the door bolt.

Also, operation of the bolt requires three operations, i.e. turning it through 90 to release it for sliding, sliding it from one position to the other and then turning it back through 90 to secure it in the new position.

Proposals have been made previously with the object of avoiding rotary bolts-see for example Patent Nos. 1 373041 and 1447702but these have tended to be relatively uneconomic to manufacture since, in the case of Patent No. 1373041, a special spring is required and, in the case of Patent No. 1447702, a specially constructed bolt handle is used.

The object of the present invention is to provide an improved fastening device of the kind referred to which makes use of a nonrotary sliding bolt and is economical to manufacture, simple to operate and avoids the use of complicated retaining slots which tend to detract from the appearance of the article.

According to the present invention we provide a fastening device of the kind referred to in which the bolt is accommodated in the housing with sufficient lateral clearance to enable a formation on the bolt to be moved out of engagement with the retaining formation or formations by shifting the bolt laterally by means of the bolt handle, spring means being provided to bias the bolt laterally in the direction of engagement between the bolt formation and said retaining formation or formations.

Thus, the spring means enables the bolt to be secured automatically against sliding when the handle is released and elaborate rotary manipulation of the bolt is unnecessary in order to secure it. Also the handle may project through a simple axial slot in the housing thereby avoiding unsightly U-shaped slots and potential dirt collecting points on the bolt housing.

In a preferred embodiment, the bolt formation is located on the opposite side of the bolt to the handle in substantially the same axial position along the bolt length and the or each retaining formation is provided in an adjacent surface or surfaces of the bolt housing at that side of the housing which is to be affixed to a door or the like.

The housing is conveniently manufactured as an extruded section (of aluminium or aluminium alloy for example and comprises a generally U-shaped portion, which non-rotatably receives the bolt, and lateral flanges adjacent the mouth of the U such that the flanges encroach part-way across the mouth to trap the bolt and also extend outwardly of the Ushaped formation to provide attachment plates by means of which the housing can be secured to a door or such like by screws passing through apertures in the flanges.

The retaining formations for cooperation with the formation on the bolt may be formed by indentations in the edges of the encroaching portions of the flanges such that the bolt formation can register with the indentations and enter the gap between the flanges when the bolt is in the fully extended and/or retracted position but is held out of the gap by the encroaching portions of the flanges at other positions of the bolt.

The spring means conveniently comprises a curved blade spring located between one face of the bolt and an adjacent face of the housing, e.g. the base of the U-shaped portion.

For aesthetic reasons, the cross-sectional shape of the keeper is conveniently substantially identical to the extruded section of the bolt housing and means is provided for preventing any tendency for the bolt to rattle in the keeper. This may be achieved by eliminating that form of lateral clearance between the bolt and the interior of the keeper which is likely to lead to rattle, e.g. the bolt may be enlarged at its end or provided with a projection serving to take up clearance or the keeper may be provided with an internal projection for the same purpose. Alternatively the bolt may be shaped or displaced in the region of its keeper-engaging end so that any clearance between itself and the keeper is located at that side of the bolt which faces the surface to which the keeper is attached in use rather than at the opposite side of the bolt.

In order to promote further understanding of the invention, examples thereof will now be described with reference to the accompanying drawings in which: Figure 1 is a plan view of the bolt and keeper assembly; Figure 2 is an axial section of the bolt and keeper assembly; Figure 3 is an underside view of the as assembly; Figure 4 is a fragmentary view showing a modification; and Figure 5 is a fragmentary view showing another modification.

Referring firstly to Figs. 1 to 3, the device comprises a housing 10 of extruded section comprising a U-shaped central portion 1 2 and lateral flanges 14 which for the most part extend outwardly to form attachment plates to enable the housing to be attached to a door or such like with the flanges 14 in face to face to relation with the door surface. The flanges 14 also project laterally inwardly to some extent so as to form lips 16 (Fig. 3) which encroach part way across the mouth of the U thereby leaving a gap 18.

A bolt 20 is slidably but non-rotatably received in the U-shaped portion 1 2 with substantial clearance as indicated by reference numeral 22 (see Fig. 2). The handle 24 is attached to the bolt and extends through the base wall 26 of the channel 1 2 via an axial slot 28 which by cooperation with the handle limits the fully extended and retracted positions of the bolt. The bolt is trapped in the channel 1 2 by the lips 1 6 and is biased by a curved plate spring 30 so as to normally seat on the lips at least over the major part of its length.

On its underside, the bolt is provided with a projection 32, which may comprise a washer surrounding the stem of the handle and may be secured in place by peening over or otherwise deforming the end of the handle stem.

The diameter of the projection 32 is larger than the space between the lips 1 6 but nevertheless can fit into the gap 1 8 by virtue of retaining indentations 34, 36 at axial locations corresponding to the limiting positions of the bolt. Thus, in each limiting position, the spring 30 urges the projection 32 to seat into the indentations 34 or 36 and thereby prevent sliding of the bolt. To free the bolt for adjustment to its other limiting position, the handle is pulled against the spring loading to lift the projection out of for example the indentations 34. The bolt can then be moved until the handle reaches the other end of the slot 28.If the handle is now released the bolt is automatically driven downwardly by the spring towards the lips 1 6 with consequent seating of the projection 32 in the indentation 36 to prevent unintended sliding of the bolt.

The keeper 38 for the bolt may be cut from an extrusion of the same section as the housing 10. In this event, to prevent rattle owing to the fact that the section of the extrusion is dimensioned to provide subtantial lateral clearance for the bolt, the bolt may be shaped so that it bears against the base 40 of the keeper (see Fig. 2). Figs. 4 and 5 illustrate alternative anti-rattle means, e.g. a projection 42 on the bolt end as in Fig. 4 or a projection or projections 44 on the lips of the keeper as in Fig. 5.

Preferably means may also be provided for preventing or minimising fulcrumming of the bolt within the housing at the end adjacent the keeper since such fulcrumming may result in the projection 32 lifting out of the indentations 34, 36 when this is not desired, for instance as a result of pressure being applied against the door. Thus, for example, a projection may be provided on the bolt or on the housing in the vicinity of the keeper to reduce any tendency for the bolt to fulcrum in that region.

Claims (11)

1. A fastening device of the kind referred to in which the bolt is accommodated in the housing with sufficient lateral clearance to enable a formation on the bolt to be moved out of engagement with the retaining formation or formations by shifting the bolt laterally by means of the bolt handle, spring means being provided to bias the bolt laterally in the direction of engagement between the bolt formation and said retaining formation or formations.

2. A fastening device as claimed in Claim 1 in which the bolt formation is located on the opposite side of the bolt to the handle in substantially the same axial position along the bolt length.

3. A fastening device as claimed in Claim 1 or 2 in which the or each retaining formation is provided in an adjacent surface or surfaces of the bolt housing at that side of the housing which is to be affixed to a door or the like.

4. A fastening device as claimed in Claim 1, 2 or 3 in which the housing comprises a generally U-shaped portion, which non-rotatably receives the bolt, and lateral flanges adjacent the mouth of the U such that the flanges encroach part-way across the mouth to trap the bolt and also extend outwardly of the Ushaped formation to provide attachment plates by means of which the housing can be secured to a door or such like by screws passing through apertures in the flanges.

5. A fastening device as claimed in Claim 4 in which the retaining formations for coop eration with the formation on the bolt are formed by indentations in the edges of the encroaching portions of the flanges such that the bolt formation can register with the indentations and enter the gap between the flanges when the bolt is in the fully extended and/or retracted position but is held out of the gap by the encroaching portions of the flanges at other positions of the bolt.

6. A fastening device as claimed in any one of Claims 1-5 in which the spring means comprises a curved blade spring located between one face of the bolt and an adjacent face of the housing.

7. A fastening device as claimed in any one of Claims 1-6 in which means is provided for preventing any tendency for the bolt to rattle in the keeper.

8. A fastening device as claimed in Claim 7 in which such anti-rattle means serves to eliminate clearance between the bolt in a lateral direction in which there is otherwise a tendency for rattle to occur.

9. A fastening device as claimed in Claim 8 in which the bolt is enlarged at its end or provided with a projection serving to take up clearance or the keeper may be provided with an internal projection for the same purpose.

10. A fastening device as claimed in Claim 8 in which the bolt is shaped or displaced in the region of its keeper-engaging end so that any clearance between itself and the keeper is located at that side of the bolt which faces the surface to which the keeper is attached in use.

11. A fastening device substantially as hereinbefore described with reference to, and as shown in, Figs. 1 to 3, or Figs. 1 to 3 when modified by Fig. 4 or 5, of the accompanying drawings.