GB2357313A

GB2357313A - Door lock

Info

Publication number: GB2357313A
Application number: GB9929591A
Authority: GB
Inventors: Alan James Maple
Original assignee: Maple & Sons Ltd J
Current assignee: Maple & Sons Ltd J
Priority date: 1999-12-16
Filing date: 1999-12-16
Publication date: 2001-06-20
Anticipated expiration: 2019-12-16
Also published as: GB2357313B; GB9929591D0

Abstract

A dead-lock arrangement for a vehicle door comprises a bolt mechanism 10 having a bolt housing 13 adapted to be secured to an edge region of a vehicle door and a bolt 16 slidably mounted in the housing. The bolt 16 has a toothed rack which is meshed with a gear rotatably mounted in the housing. A lock mechanism 11 is adapted for securing to a panel of the door and has a cylinder which is rotatable with respect to the mount by means of a key fitted into a cylinder. A flexible drive shaft 12 interconnects the cylinder of the lock mechanism 11 and the gear of the bolt mechanism 10 so that rotation of the cylinder by the key causes the bolt 16 to project from or be withdrawn into the housing 13. The bolt mechanism may thus be mounted on the door at a position where security is enhanced and the lock mechanism may be mounted at a convenient position on the door, both for operation of the mechanism by a key and where the door has sufficient depth to accommodate the lock mechanism.

Description

2357313 DOOR LOCKS This invention relates to a dead-lock arrangement for a

vehicle door.

Most motor vehicles are fitted as standard by the vehicle manufacturer with a relatively simple door-locking arrangement, for preventing unauthorised opening of a door. Typically, there may be a latching bolt mounted on the door and which co-operates with a catch plate on the door frame. The bolt may be released from the catch plate by operation of an internal or external door handle. A lock associated with the handle may serve to prevent movement of the handle, and so prevent releasing of the bolt.

The security afforded by a door-lock arrangement as described above is relatively low. Generally, it is easy to force the mechanism simply by applying sufficient force to the locked door handle, so breaking the lock mechanism and permitting opening of the door. Consequently, in circumstances where greater security is required, for example to protect goods carried within a passenger car or van, it is known to retro-fit a deal- lock to each vehicle door, which lock requires the use of a separate key in a good quality lock mechanism, to effect operation of the bolt of the dead-lock.

One known form of dead-lock intended for the above purpose employs a so-called rack bolt having a housing in which is slidably mounted a bolt with a toothed rack engageable by a toothed (splined) shaft. When the housing is mounted on an edge of a door, to engage a suitable receptor in the door frame, there are considerable difficulties in achieving a proper alignment between the bolt and a lock mechanism fitted to the outer door panel and drivingly connected to the splined shaft. Moreover, for many vehicle door constructions, there may be insufficient room to accommodate both the bolt and the lock mechanism between the panels of the door, at the required location of the bolt.

It is an aim of the present invention to provide a dead-lock arrangement for a vehicle door which is relatively easy to fit, and overcomes the space problem of the known arrangements, whilst at the same time providing a high level of security.

Accordingly, the present invention provides a dead-lock arrangement for a vehicle door, comprising:

a bolt mechanism having a bolt housing adapted for securing to an edge region of vehicle door, a bolt slidably mounted in the housing and including a toothed rack, and a gear rotatably mounted in the housing and meshing with the toothed rack; a lock mechanism including a mount adapted for securing to a panel of the door and a cylinder rotatable with respect to the mount by means of a key fitted into the cylinder; and a flexible drive shaft interconnecting the cylinder of the lock mechanism and the gear of the bolt mechanism, whereby rotation of the cylinder by means of the key causes the bolt to project from or be withdrawn into the bolt housing.

It will be appreciated that with the arrangement of the present invention, the lock mechanism may be mounted on the vehicle door at any convenient location, where there is sufficient room to accommodate the cylinder lock, even if of a high-security design. Further, that location may be selected so that there is relatively easy access from the interior of the door, for the mounting of the lock mechanism. Then, by having a flexible drive shaft interconnecting the cylinder of the lock mechanism and the splined shaft of the bolt mechanism, the bolt mechanism may be mounted on the edge of a door at a location where there is a sufficiently flat edge surface and where the bolt may engage with a sufficiently strong part of the door frame.

In addition, a single set of components may fit a very large number of different vehicle doors, the only adjustment required being the cutting of the flexible drive shaft to the required length - but by providing a loop in that shaft, it may not even be necessary to trim the length of the shaft.

The flexible drive shaft could be in the form of an exposed shaft which is torsionally rigid and substantially inextensible along its length, but relatively flexible in the radial direction. In the alternative, the drive shaft may comprise an outer sheath extending at least part-way between the lock mechanism and the bolt mechanism, and a flexible drive cable disposed within the sheath and connected to the cylinder of the lock mechanism and the splined shaft of the bolt mechanism.

In order to facilitate the accommodation of the lock arrangement of this invention when there is a relatively small separation between the external skin of the door and an internal panel, a right-angle drive gearbox may be provided on the lock mechanism, the cylinder of the lock being coupled to the gearbox input and the flexible shaft to the gearbox output. In this way, no room is required behind the lock to accommodate a loop of the flexible shaft, which normally will have a minimum permissible radius of curative. Further, the bolt mechanism may also include such a right angle drive gearbox, flexible drive shaft being coupled to the gearbox input and the splined shaft of the bolt mechanism to the gearbox output. Again, this permits the accommodation-of the bolt mechanism in a location where there may be a limited space.

The lock arrangement of this invention as described above may be modified to permit the simultaneous operation of two similar bolt mechanisms having respective bolt housings and adapted for securing to spaced-apart edge regions of the vehicle door. To allow a single lock mechanism to drive both bolts, there may be provided a splitter gearbox having one input shaft and two output shafts driven by the input shaft. The flexible drive shaft connected to the lock mechanism cylinder may be arranged to drive the gearbox input shaft, each of the two output shafts being drivingly connected to the respective bolt splined shafts, by means of two further flexible drive shafts.

In an alternative form of splitter gearbox, there may be provided a train of three gears with the lock mechanism flexible drive shaft connected to the central gear of the train, and each of the other two gears being connected to a respective further flexible - drive shaft in turn connected to the splined shaft of the associated two bolt mechanism.

By way of example only, certain specific embodiments of a vehicle door lock arrangement constructed in accordance with the present invention will now be described, reference being made to the accompanying drawings in which:- Figure 1 shows a first embodiment of the lock arrangement; Figure 2 shows a modified form of the lock arrangement of Figure 1; Figure 3 illustrates a typical installation, using the lock arrangement of Figure 1 or Figure 2; Figure 4 is an exploded view of a splitter gearbox suitable for use in a lock arrangement having two bolt mechanisms; and Figure 5 illustrates the connection of drive cables to the gears of the gearbox of Figure 4.

Referring initially to Figure 1, there is shown a first embodiment of a dead-lock arrangement of this invention, for fitting to a motor vehicle door.

This arrangement comprises a bolt mechanism 10, a lock mechanism 11, and a flexible drive shaft 12, interconnecting the lock mechanism and the bolt mechanism. The bolt mechanism 10 has a housing 13 with a circular flange 14 at one end, the flange having two mounting holes 15, by means of which the housing may be secured to the edge of a vehicle door, using selftapping screws or blind rivets. A bolt 16 is slidably mounted within the housing 13 and has a linear toothed rack (not shown) formed along a part of the bolt normally located within the housing. The housing also defines a transverse bore within which is positioned a splined shaft 17 meshing with the teeth of the bolt rack, whereby rotation of the splined shaft causes the bolt to project from the flanged end of the housing 13, or to be withdrawn into the housing, depending upon the direction of rotation of the shaft 17.

The lock mechanism 11 is an essentially conventional high security key operated cylinder lock. Thus, the mechanism includes a housing 19 having a flange 20 at one end, the external surface 21 of the housing being threaded and provided with a flat 22 extending therealong. When the housing is fitted into a D-shaped hole in a panel, it may be secured in position by a nut (not shown) engaged with the threaded surface 21, the housing being held against rotation by the flat 22 engaging the corresponding flat in the panel hole. The lock has a cylinder (not shown) fitted within the housing and which is rotatable by a key 24 having a suitable configuration to operate the lock tumblers, so freeing the cylinder for rotation. The end of the cylinder remote from the flange 20 is provided with a axial hole of a square cross-sectional shape, which hole is exposed through the end wall of the housing 19 remote from flange 20.

One end portion of the flexible drive shaft 12 is finished to have a square cross-sectional shape of a size suitable for being received in the square cross-section hole in the end of the cylinder. The other end of the flexible drive shaft is received in a bore provided in a reduced diameter section of the splined shaft 17, that section then being swaged on to the flexible shaft so as to secure the two shafts together. A circlip 26 is fitted into a groove formed in the splined shaft 17, to retain that shaft within the bolt housing 13.

The drive shaft may take any one of a number of different forms so long as the cable is able to transmit rotational drive from the lock cylinder to the splined shaft 17, despite the flexible shaft following a curved path having several radii, as shown for example in Figure 1. For example, the flexible shaft could comprise a helically-wound spring steel wire covered with a plastics material. In the alternative, the flexible shaft may comprise a two-piece component, having a flexible outer sheath which is secured at one end (and typically the bolt mechanism end) to a fixed component, and a rotatable drive cable extending along the length of the sheath. Such drive cables are well known for transmission of rotary motion and form no part of the present invention, as such; the cable will not therefore be described in further detail here.

Figure 2 shows an alternative lock arrangement, but like parts with those of Figure 1 are given like reference numbers. Here, a right angle drive gearbox 27 is connected to the lock housing 19 and receives the drive from the lock cylinder. The flexible drive shaft 12 connects with the output from the gearbox 27, extending at right angles to the axis of rotation of the cylinder.

The gearbox is supported on a mounting plate 28 which fits over the surface 21 of the lock housing; in this way, the gearbox 27 will be secured to the end of the cylinder lock by the same nut which holds the lock for example to a door panel.

Figure 3 shows a typical installation of either dead-lock arrangement described above. Below the conventional door lock mechanism 30 of a vehicle door 31, there is mounted the housing 13 of the bolt mechanism 10.

A suitable recess is drilled into the corresponding position in the door frame and may be reinforced if required by a striker plate. Below the conventional door handle 32, a D-shaped hole is cut to receive the cylinder lock housing 19, which is then secured in position by removing a panel from the interior of the door and tightening a nut on to the threaded surface 21. A weather flap, ?9 may be fitted over the exposed part of the cylinder lock, if required.

The key 24 is inserted into the lock and is turned to the "open" position.

The bolt 16 is pushed fully into its housing 13 and then the splined shaft 17 is pushed through the bore in the bolt housing to engage with the teeth of the bolt rack. Then, the circlip 26 is fitted to the splined shaft and the other end portion of the flexible cable drive shaft is inserted into the square hole in the lock cylinder. Finally, the end portion of the flexible shaft is secured in position, for example by means of a grub screw threaded radially into the cylinder to engage the cable.

In use, when the vehicle door 31 is to be secured closed, it can be dead-locked by causing the bolt 16 to project into the hole provided in the door frame by means of the key 24 inserted into the lock mechanism.

A single lock mechanism may also be used simultaneously to operate two bolt mechanisms each similar to that shown in Figures 1 and 2, for example for the dead-locking of a van door. In this case, the bolt mechanisms may be provided along the top and bottom edges of the van door, to engage corresponding frame portions, when locked. To permit a single flexible shaft driven by a single cylinder lock to effect operation of two bolt mechanisms, that flexible drive shaft is taken to a splitter gearbox 30 shown in Figures 4 and 5.

This has a train of three meshing gears 31,32,33, each of which is rotatably supported within the gearbox casing 34 and has a central hole 35 of a square cross-sectional shape. The end portion of the drive shaft from the lock cylinder is finished square and is received in the hole 35 of the central gear 31.

Two separate drive cables 35, 36 are connected to the two bolt mechanisms respectively, and have squared end portions remote from the bolt mechanisms. These end portions are received in the holes 35 of the other two gears 32,33. In this way, rotation of the lock cylinder causes simultaneous -g- rotation in the same sense of the two drive shafts 35, 36, to effect projection or withdrawal of the respective bolts.

Claims

1 A dead-lock arrangement for a vehicle door, comprising:

2. A dead-lock arrangement as claimed in claim 1, wherein the flexible drive shaft comprises an outer sheath extending between the lock mechanism and the bolt mechanism, and a rotatable cable extending within the sheath and connected to the cylinder of the lock mechanism and the gear of the bolt mechanism.

3. A dead-lock arrangement as claimed in claim 1 or claim 2, wherein the lock mechanism includes a right-angle drive gear-box having an input shaft driven by the lock cylinder and an output shaft connected to the flexible drive shaft.

4. A dead-lock arrangement as claimed in any of the preceding claims, wherein the bolt mechanism includes a right-angle drive gear-box having. an input shaft driven by the flexible drive shaft and an output shaft connected to or forming the bolt mechanism gear.

5. A dead-lock arrangement as claimed in any of the preceding claims, wherein there are two similar bolt mechanisms having a respective bolt housings adapted for securing to spaced-apart edge regions of vehicle door, the two bolt mechanism gears being driven by a single lock mechanism cylinder.

6. A dead-lock arrangement as claimed in claim 5, wherein there.. is provided a splitter gear-box having one input shaft and two output shafts driven by the input shaft, the flexible drive shaft connected to the lock mechanism cylinder being arranged to drive the gear-box input shaft and the each of the two gear box output shafts being coupled to a respective further flexible drive shaft each of which is drivingly connected to the respective gear of the associated two bolt mechanisms.

7. A dead-lock arrangement as claimed in claim 6, wherein the splitter gear box comprises a train of three gears, the input shaft carrying the central gear and each output shaft carrying one of the other two gears, respectively.

8. A dead-lock arrangement as claimed in claim 5, wherein there" is provided a splitter gear box comprising a train of three gears, the flexible drive shaft connected to the lock mechanism cylinder being arranged to drive the central gear of the train, and each of the other two gears being coupled to a respective further flexible drive shaft each of which is connected to the respective gear of the associated two bolt mechanisms.

9. A dead-lock arrangement as claimed in claim 1 and substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings. As hereinbefore described with reference to and as illustrated in the accompanying drawings.

10. A vehicle whenever at least one door is fitted with a lock arrangement as claimed in any of the preceding claims, the lock mechanism being fitted to a door panel so as to be accessible from the exterior, when the door is closed.