GB2275961A

GB2275961A - A door bolt

Info

Publication number: GB2275961A
Application number: GB9304932A
Authority: GB
Inventors: Charles Edward Alan Milner
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-03-10
Filing date: 1993-03-10
Publication date: 1994-09-14
Anticipated expiration: 2013-03-10
Also published as: GB2275961B; GB9304932D0; DE9403985U1; FR2704896A3; FR2704896B3

Abstract

a door bolt has a pair of aligned guide tunnels (20) carrying a bolt bar (22) which has a radical travelling eye (28) for securing against any one of four fixed eyes (34, 36, 44, 46) by a padlock bar (42). Each eye has a diameter less than twice its length (L). <IMAGE>

Description

A DOOR BOLT This invention relates to door bolts for use with padlocks.

According to the invention, a door bolt for use with a padlock has a base, a bolt bar carried in longitudinal guide means on the base and carrying a radial first securing eye for alignment, in a locking position of the bolt bar, with a second securing eye carried by the base, so that a lockable bar of the padlock can fit through both eyes, the bolt bar being rotatable about its axis between its locking position and a free position in which it can be withdrawn.

Each eye preferably comprises an element defining at least one radial surface for face-to-face cooperation with a corresponding surface of the other eye, the said eye element having a longitudinal hole with a diameter less than twice the length of the eye element.

The base preferably carries more than one of the said second eyes, including one to which the first eye, carried by the bolt bar, can be secured by a padlock when the bolt bar is withdrawn.

A door bolt in a preferred form according to the invention will now be described, by way of example only and with reference to the accompanying drawings, in which:- Figure 1 is a front elevation showing the bolt mounted on a door; and Figures 2 and 3, on a larger scale, are cross-sectional elevations of the bolt itself, taken on the lines II-II and III-III respectively.

Referring to the drawings, a door 10 is secured to a door frame 12 by a releasable bolt 14, which can be locked by means of a padlock. The bolt 14 has a flat rectangular base 16 secured to the door 10 in any suitable way, e.g. by means of screws (not shown) through holes 18 in the base. The latter carries guide means 20 in which a bolt bar 22 is supported on a horizontal axis 24, the bolt bar 22 being movable axially between the securing position shown in Figure 1 in full lines, and a withdrawn position indicated in phantom lines at 22'. In its securing position the bar 22 engages in a staple indicated in phantom lines at 26, which is secured to the door frame 12, while in its withdrawn position it is free of the staple so that the door can be opened.

In this example, the guide means 20 consists of a pair of open ended guide tunnels, one at each end of the base 16. As shown, they are of square cross section and welded to the base. It will be understood however that the guide means can take any suitable form.

The bolt bar 22 carries a first, or travelling, securing eye 28, which consists of an eye element of substantial thickness, i.e. substantial length in the direction of the axis 24. This eye element is integral with the bar 22 or securely fastened to it, for example by welding. It has two radial parallel faces 30 and a through hole 32.

The bolt bar 22 is freely rotatable in the guide tunnels 20 about the axis 24, between the locking position shown in full lines in Figures 1 and 2, and a free position in which the bolt bar can be withdrawn from the staple 26 or inserted in it. This free position is the position of the eye 28 indicated in phantom lines at 28' in Figure 2, though it will be realised from the rest of this description that there is a wide range of these free positions.

The base 16 carries a pair of second, or fixed, eyes 34 and 36, projecting from the base to one side of the bolt bar 22. Each of these fixed eyes consists of an eye element formed with a through hole of substantially the same diameter as the hole 32 in the travelling eye 28, with which it is aligned when the bolt bar 22 is in its securing position shown. In this position one radial face 30 of the eye 28 lies in abutting contact with, or at least very close to, a corresponding radial face 40 (see Figure 2) or 41 (see Figure 1) of the eye 34 or 36 respectively.When the bolt is in its securing position (full lines in Figure 1), one of the faces 30 cooperates with the face 40 of the eye 34; when the bolt is withdrawn, it can be rotated to its locking position so that the other radial face 30 of the eye 28 cooperates similarly with the face 41 of the eye 36 (in which position the eye 28 is indicated at 28" in Figure 1). In both cases the lockable bar 42 of the padlock is inserted through the hole 32 in the travelling eye 28 and the hole 38 of the adjacent fixed eye, so as to secure the bolt bar 22 in either its securing or its withdrawn position, as appropriate.

It will be noted that the bolt 14 is made of metal, preferably steel, of substantialthickness. In particular, the horizontal length of each eye 28, 34, 36 is more than half the diameter of the hole through the corresponding eye. In a typical example this length, L, is 8 mm, while the diameter D of the holes is 13 mm, i.e. less than twice the length L.

In the embodiment shown, two further fixed eyes 44 and 46 are carried by the base 16 on the other side of the bolt bar, so that by use of the eye 44 the bolt can be used as a left-hand bolt instead of a right-hand bolt as shown. The eyes 44 and 46 are substantially identical to the eyes 34 and 36.

The fixed eyes may be integral with the base, as may the guide tunnels 20. The resulting component will then typically be a casting, the through holes in the guide tunnels and fixed eyes being drilled. As shown, however, this is a fabricated component. Similarly the bolt bar 22 may be forged or cast, with the travelling eye 28 then being integral with it.

It will be realised that this bolt is of particularly robust construction, giving a high degree of security which can be enhanced by, for example, suitable surface hardening treatment of some or all of the components to increase their resistance to tampering (e.g. attempts to use a saw or the like). The dimensions of the eyes may be selected so as to enable a padlock of a particular selected design to be secured quite tightly when the padlock bar 42 is locked in position, i.e.

with substantially no axial movement of the bolt bar being possible. In this connection it will be observed that Figure 1 shows the bar 42 engaging in the holes 32 and 38 in, effectively, three-point wedging contact.

Claims

1. A door bolt for use with a padlock, wherein the bolt comprises a base and a bolt bar carried in longitudinal guide means on the base, the bolt bar carrying a radial first securing eye for alignment, in a locking position of the bolt bar, with a second securing eye carried by the base, so that a lockable bar of the padlock can fit through both eyes, the bolt bar being rotatable about its axis between its locking position and a free position in which it can be withdrawn.

2. A bolt according to Claim 1, wherein each eye comprises an eye element defining at least one radial surface for face-to-face cooperation with a corresponding surface of the other eye, each said eye element having a longitudinal hole the diameter of which is less than twice the length of the eye element.

3. A bolt according to Claim 1 or Claim 2, wherein the base carries more than one of the said second eyes, including one to which the first eye, carried by the bolt bar, can be secured by a padlock when the bolt bar is withdrawn.

4. A door bolt substantially as described in the foregoing description with reference to the accompanying drawings.

Amendments to the claims have been filed as follows 1. A door bolt for use with a padlock, wherein the bolt comprises a base and a bolt bar carried in longitudinal guide means on the base, the bolt bar carrying an offset radial first securing eye for alignment, in a locking orientation of the bolt bar, with a second securing eye carried by the base, so that a lockable bar of the padlock can fit through both eyes, the bolt bar being rotatable about its axis between its locking orientation and a free orientation, in which the offset first eye can project laterally whereby the bolt bar can be withdrawn.

4. A bolt according to any one of the preceding Claims, wherein the guide means comprises a pair of guide tunnels of square cross section.

5. A door bolt substantially as described in the foregoing description with reference to the accompanying drawings.