VEHICLE WINDOW SILL KNOB DEVICE

Abstract: A vehicle sill knob device comprises an elongate body (10) to be gripped by the fingers pf a user, said elongate member having a bore (11) therethrough to receive the stem (14) of a locking member of a lock in which said locking member is mov­ able between locked and unlocked conditions. The body (10) has to recess (12) extending into said body from the upper end and is capable of receiving the head (13) of the locking member when the latter is in its locked position to prevent engagement of said head by a filament such as a wire tape for lifting said body. The exterior surface of said elongate body is free from pro­ trusions engageable by a filament such as a wire or tape and is shaped such that the body cannot readily be gripped by a fila­ ment such as a wire or tape, the lower end of the body being shaped such that it engages the surface of the sill so as to leave no surface engageable by a filament or tool otherwise capable of lifting said body.

Description: This invention relates to a vehicle window sill knob anti-theft device, according to the preamble of claim 1. It is well known that many vehicles are stolen or broken into by the simple expedient of inserting a wire or piece of packing case tape through the space between the door frame and window, the wire or tape being forged around the usual rubber moulding into which the edge of the window is seated. The wire or tape is then looped around the locking member, commonly a knob, of the door lock and the lock actuated to an unlocked condition. Anti-theft devices are known from prior art which includes inter alia DE-A1-2 745 711, DE-A-2 126 829, DE-A-1 653 962, DE-A1-2 450 723, US-3 915 485, US-2 853 332, US-4 239 270, US-2 730 395, US-3 474 648, US-3 623 758, US-4 202 571, US-3 860 278, US 4 098 529 and US-3 501 187. Of these Patent No. 3 501 187 to Saksa et al is believed to be the closest prior art in that an elongate body and a bore which receives the head of the door lock are disclosed. However, the safety sleeve of Saksa is resilient and does not meet the level of security achieved by the present invention. The object of the present invention is to provide an anti-theft device for vehicle door locks to prevent the locking member being lifted thereby to prevent unauthorised entry, the device being practical, effective, of low construction cost and being adaptable to a wide range of vehicles. According to the invention there is provided an anti-theft device for vehicle door locks of the type having an elongated stem which is vertically reciprocally movable between an upper unlocked position and a lower locked position with respect to the door sill adjacent a vehicle window and wherein an enlarged head is carried on the upper end of the lock stem comprising an elongate body having an exterior surface portion and upper and lower ends, said lower end of said body being engageable with the door sill, a bore extending through said body from said upper to said lower end thereof, said bore being of a size to receive the stem of the door lock therethrough, said bore having a recess extending into said body from said upper end and toward said lower end thereof, said recess being of a size to receive the head of the door lock therein, and a shoulder formed between said bore and said recess, characterized in that said elongate body is rigid, in that said recess extends along a major portion of the height of the body, and in that a resilient means is disposed within said recess and has a lower end seated with said shoulder and an upper end extending toward said upper end of said body, said upper end of said resilient means being engageable by the head of the door lock when said body is mounted in encircling relationship about the stem of the door lock, said resilient means continuously urging said body toward the door sill when the head of the door lock is positioned within said recess. The arrangement of the present invention serves to prevent engagement of said head by a filament such as a wire or tape for lifting said body. Preferably the exterior surface of said elongate body is free from protrusions engageable by a filament such as a wire or tape and is shaped such that the body cannot readily be gripped by a filament-such as a wire or tape. The provision of a lip extending axially which when the elongate member is in the lowermost position digs into the fabric of the door capping or into a deformable washer intermediate the capping and the head gives greater safety against unauthorised insertion of a wire beneath the head. By ensuring that the knob is inaccessible when the locking member is pushed down it is not possible for a loop to be manipulated into a position by which the locking member can be raised. Neither is it possible for a screwdriver or other such tool to be inserted under the knob. The invention will now be described by way of example with reference to the accompanying drawings in which: FIGURE 1 is a perspective view of a portion of a vehicle door interior with the anti-theft knob device located on the sill locking member, and FIGURE 2 is a longitudinal section through an anti-theft knob device with the locking member in the locked position. The anti-theft knob device comprises a substantially frusto conical body member 10 of suitably high density plastics material having a bore 11 therein to enable the stem 14 of a sill locking member of a lock mechanism (shown schematically in Figure 1) to pass therethrough, said bore having a recess 12 formed therein at its upper end capable of receiving the head or knob 13 of the locking member 14 when the latter is in its locked position. As shown in Figure 2 the recess 12 extends over a major portion of the axial length of the body terminating in a shoulder 19. A coiled compression spring 20 of substantially conic form overall is provided within the recess 12. The spring maintains the lip 17 in engagement with the door capping. By means of the provision of the spring accommodated within a relatively long recess the anti-theft device is suited to a wide range of door locks where the locking/unlocking stroke of the locking member varies from model to model. The bottom of the body member 10 may be provided with a lip 17 so that on locking the body grips the trim to make a tight fit without a gap beneath the body. Alternatively or in addition a self-adhesive rubber washer may be provided beneath the base having a slightly larger diameter than the body at its base. The body would then grip the washer firmly when locking takes place so as to secure the body tightly. By providing a conical surface to the body it is not possible to engage a loop of wire or metal band on the body. The body may alternatively be cylindrical or a solid of revolution of tapered form having a concave generatrix. In any construction although free from protrusions the surface may have a slightly roughened or dimpled surface sufficient to assist manual gripping but insufficient to permit purchase by a wire or metal tape. To apply the device the user merely unscrews the locking member 14 and withdraws it from the door body, slips the body 10 and spring 20 on to the member 14 which is then screwed back into the door body to re-engage the lock mechanism. With the locking member in the locked position it is only possible to lift the locking member by gripping and raising the anti-theft device from within the vehicle in the normal way. The recess 12 may have slightly sloping walls so as to allow easy passage for the head of the locking member as it is pressed down. The inside edge of the upper end of the recess may be radiused to ensure that the head is not impeded at the end of the downward locking stroke of the locking member. The many different models of cars have many different lengths and thickness of locking knobs. Therefore different shapes and lengths of cone or cylinder would be made for Audi cars, for example, where the locking knob drops a long way upon locking. The recess at the top is therefore made deeper to accommodate the greater downward stroke of locking knob. Some cars have a narrower top to the door capping, therefore this is taken into account when designing the elongate body to suit that particular car. The use of the washer only without the lip 17 may be preferred where the capping is of a hard material or where a customer would not like the lip digging into the material thus causing damage. The lower surface of the body 10 may be specially shaped to accommodate an inclined door capping. However, different shapes may be provided according to the shape of the capping. The lower edge of the body may have a lip which engages the upper surface of a rubber washer about 3 mm thick which on its other side is provided with an adhesive so that the washer once applied remains attached to the capping. The exterior surface of the elongate body is preferably free from protrusions and is of such shape that it is not possible to effect a purchase of a piece of wire or tape on the body. A cylindrical surface may suffice but more especially suitable is a frustum of a cone as shown. Preferably the sides of the body are tapered from a larger cross-sectional area at its base to a region of smaller cross-sectional area. The cone is of sufficient dimension to ensure that it can be lifted easily by the authorised user and may be made of high density plastic or light alloy. A vertical flattened surface (not shown) may be provided on one side of the body to ensure clearance between the latter and the window. The embodiments described above may be modified by the provision of an external substantially rectilinear flange (not shown) extending radially to a distance of about 1 to 2 mm and about 1 to 2 mm axially, the lower surface of the flange being at the level of the lower surface of the body. In the case of the embodiment with the flattened surface the flange will be provided only on the circular peripheral portion. The flange provides an additional safeguard against attempts to slide a wire down the surface of the cone and under the body to lift it up.

Claims: 1. An anti-theft device for vehicle door locks of the type having an elongated stem (14) which is vertically reciprocally movable between an upper unlocked position and a lower locked position with respect to the door sill adjacent a vehicle window and wherein an enlarged head (13) is carried on the upper end of the lock stem (14), the device comprising an elongate body (10) having an exterior surface portion and upper and lower ends, said lower end of said body being engageable with the door still, a bore (11) extending through said body from said upper to said lower end thereof, said bore being of a size to receive the stem (14) of the door lock therethrough, said bore (11) having a recess (12) extending into said body (10) from said upper end and toward said lower end thereof, said recess being of a size to receive the head of the door lock therein, and a shoulder (19) formed between said bore (11) and said recess (12), characterized in that said elongate body (10) is rigid, in that said recess (12) extends along a major portion of the height of the body, and in that a resilient means (20) is disposed within said recess (12) and has a lower end seated with said shoulder (19) and an upper end extending toward said upper end of said body, said upper end of said resilient means (20) being engageable by the head (13) of the door lock when said body is mounted in encircling relationship about the stem (14) of the door lock, said resilient means (20) continuously urging said body toward the door sill when the head of the door lock is positioned within said recess. 2. The anti-theft device of Claim 1, characterized in that said body (10) includes a flange portion extending radially outwardly from said lower end thereof so as to be in abutting contact with the door sill when said body is placed about the stem (14) of the door lock. 3. The anti-theft device of Claim 1, characterized in that said exterior surface portion of said body is in the shape of a frustum of a cone. 4. The anti-theft device of Claim 1, characterized in that said exterior surface portion of said body is in the shape of a frustum of a cone having a portion thereof formed as a flattened surface. 5. The anti-theft device of Claim 4, characterized by a radial flange extending outwardly from said lower end of said body along the conical portions thereof. 6. The anti-theft device of Claim 1, characterized in that said body includes a lip (17) depending from said lower end thereof, said lip gripping the door sill when said door lock is in a locked position. 7. The anti-theft device of Claim 6, characterized by a deformable washer means (18), said washer means (18) being positioned intermediate said lip (17) and the door sill so that on movement of the door lock to a locked position said lip (17) deforms the washer means to ensure that said body is tightly secured. 8. The anti-theft device of Claim 1, characterized in that said lower end of said body is inclined so as to cooperatively engage an inclined door sill. 9. The anti-theft device of Claim 1, characterised in that said resilient means is a coiled spring.

Inventors: APPLEFORD, STEPHEN ROBERT ANDREW
Applicants: APPLEFORD, STEPHEN ROBERT ANDREW
Application year: 1987
Main classification: E05B65
IPC codes: E05B65, E05C21