WO1993008046A1

WO1993008046A1 - Hand brake lever lock

Info

Publication number: WO1993008046A1
Application number: PCT/AU1992/000565
Authority: WO
Inventors: Sydney Barry Bruce
Original assignee: Robarde International Pty. Ltd.
Priority date: 1991-10-21
Filing date: 1992-10-21
Publication date: 1993-04-29

Abstract

A hand brake lever lock comprises a combination lock mounted on a sleeve (13) adapted to fit over a hand brake lever (11) having a release button (12). The sleeve (13) has a reduced diameter portion (18) defining a bore (19) receiving a plunger (20) having pins (22) projecting through a slot (21) in the sleeve portion (18). The combination lock has register wheels (23) mounted on the sleeve portion (18) and slots (30) which, when aligned with the pins (22), allow reciprocation of the plunger (20) when activated by depressing the cap (37), while preventing reciprocation when the slots (30) are not aligned with the pins (22). Springs clips located within the register wheels (23) have legs (27) joined at an apex portion (28) for location in indentations (25a) in the register wheels (23), the legs (27) of the clips being formed with V-shaped indentations (27a) which co-operate with similarly shaped grooves (18a) in the sleeve portion (18) such that rotation of the register wheels (23) causes resilient camming of the indentations (27a) in the grooves (18a) to cam the legs (27) apart without contact between the legs (27) and the register wheels (23).

Description

HAND BRAKE LEVER LOCK Field of the Invention

This invention relates to hand brake lever locks used to deter vehicle theft. Background of the Invention

Several different forms of hand brake lever locks have been proposed in the past, and some have been marketed with limited success. The main advantage of a hand brake lever lock is that it is relatively simple to manufacture, install and operate, and is relatively less expensive than more sophisticated security devices, such as systems which serve to disable the vehicle ignition system and provide an alarm when unauthorized entry to a vehicle is effected.

Hand brake lever locks of several types are to be found in the Patent literature, and representative examples include U.S. Patent 4,858,451, Balina et al, U.K. Patent 1,088,853, Waso Limited, and European Patent Application EP404384, Taylor, each of which includes a sleeve for mounting on the operating end of a hand brake lever and having an operating push-button for actuating the release button of the hand brake lever together with a combination lock mounted on the sleeve to prevent depression of the operating push-button when in the locked condition.

The lock described in U.S. Patent 4,858,451 has achieved some commercial success, but its high cost, due to the inclusion of a blocking device which prevents actuation of the combination lock when the hand brake is in the released condition, has restricted its market penetration.

It is also important that the actuating wheels incorporate a simple but effective mechanism for locating the wheels at each indexed position. The U.K. Patent shows the use of a simple spring but it is unlikely to produce a sufficiently positive locating force and its configuration may cause frictional interference in the rotation of the wheels. g..—iai-y ₀f ■f-'htn Tnwgntion and Object

It is an object of the invention to provide a lock of the above type having a simple and inexpensive mechanism for causing positive location of the actuating wheels in their indexed positions.

The invention therefore provides a hand brake lever lock comprising a sleeve adapted to fit over the operative end of a hand brake lever having an release button, means for fixing the sleeve on the hand brake lever, plunger means mounted for reciprocating movement in the sleeve against the action of resilient means for restoring the plunger to its inoperative position, said plunger means engaging in use the release button of the hand brake lever and having an operating cap fixed to its outermost end, combination lock means carried by a portion of the sleeve of reduced dimensions and positioned to prevent movement of the plunger in the locked condition whilst allowing movement of the plunger in the unlocked condition, said combination lock including a plurality of register wheels rotatably mounted on said portion of said sleeve and each adapted to be rotatably indexed to a multiplicity of positions at only one of which the locking means is released, detent means for resiliently restraining the wheels at each of said multiplicity of positions, characterized in that each of said detent means comprises a shaped spring clip having legs which engage said portion of said sleeve, said legs being joined at an apex portion which positively engages indentations formed inside each register wheel at positions corresponding to each of said predetermined indexed positions, said legs being formed with opposed inwardly directed indentations intermediate their ends which engage similarly shaped grooves formed in the surface of said sleeve portion, said inwardly directed indentations co-operating with said grooves to resiliently slide on a surface of said grooves as the register wheels are rotated from each indexed position whereby the legs of the spring clip are resiliently spread by the camming action of the grooves whilst remaining in close proximity with the sleeve portion thereby providing a more positive detent action at each indexed position whilst avoiding contact between the legs and the register wheels. Brief Description of the Drawings

In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention and in which:

Figure 1 is a side elevation of a hand brake lever lock embodying the invention, partly sectioned to show the co¬ operation between the sleeve of the lock and the hand brake lever;

Figure 2 is a fragmentary sectional elevation of the operative portion of the hand brake lever lock of Figure 1;

Figure 3 is a sectional end elevation taken along the line 33 in Figure 22, and

Figure 4 is an exploded fragmentary perspective view of portion of the lock more clearly illustrating the spring clip and one register wheel shown in Figure 3 of the drawings.

Referring firstly to Figures 1 and 2 of the drawings, there is illustrated a hand brake lever lock 10 embodying the present invention adapted for mounting over a vehicle hand brake lever 11 supporting a release knob 12. The lock 10 includes a elongate tubular housing or first sleeve portion 13 which is^* adapted to be located over the hand brake lever 11 and which includes a series of external finger receiving grooves 14 to facilitate gripping by the user. The housing 13 also incorporates one or more threaded apertures 15 for receiving securing screws 16 provided with necked region 17 intermediate their ends whereby the screw 16 may be received in the aperture and tightened against the hand brake lever 11 until the end of the screw shears off at the neck region 17 to leave the screw 16 in the aperture 15 to leave the housing 13 permanently secured to the hand brake lever in a tamper-resistant manner.

The housing or sleeve thirteen is formed at its opposite end with an integral second sleeve portion 18 which has an internal bore 19 receiving a reciprocal plunger 20. The second sleeve portion 18 is provided with a longitudinally extending slot 21 and the plunger is provided with a plurality of radially extending pins 22 which project through the slot 21 and outwardly of the sleeve portion 18. Supported for rotation about the second sleeve portion 18 are three co-axially located register wheels 23 which control the movement of the pins 22 and in turn the plunger 20. As shown in Figures 3 and 4, the register wheels 23 are provided on one side with a generally cylindrical recess 24 defined by an inner wall 25 which is formed with a series of indentations 25a in the form of rectangular recesses equally spaced about the periphery of the wall 25. A spring clip 26 is located in each recess 24 and the spring clip has a pair of shaped legs 27 joined by a pointed apex 28, with each leg being formed with an inwardly directed generally V-shaped indentation 27a, each of which engages in a similarly shaped V-shaped depression formed along the length of the second sleeve portion at diametrically opposed positions thereof. The V-shaped indentations 27a are formed mid-way along the length of the legs 27 and the end portions 27b of the legs 27 closely conform to the surface of the second sleeve portion 18 as shown clearly in Figures 3 and 4.

It will be appreciated that as each register wheel 23 is rotated, the apex 28 of each spring clip will positively locate in one of the rectangular indentations 25a to resiliently restrain the wheel at this indexed position until a positive predetermined face is applied to the wheel 23. As the wheel 23 is rotated, the V-shaped indentations 27a slide on the lower surfaces of the grooves 18a to resiliently cam the legs 27 apart until the next indentation 25a is reached whereupon the apex 28 positively locates in the indentation 25a to resiliently restrain the register wheel 23 at this position. Thus, the spring clips 26 provide a particularly simple but effective means for resiliently indexing the register wheels 23 in a particularly positive and effective manner. The spring clip 26 provides a significant improvement over the clip shown in UK Patent 1,088,853 which would provide a relatively weak resilient indexing force and would be inclined to bind against the inner surface of the register wheel thereby creating non-positive frictional resistance rather than resilient biasing resistance. As shown in Figure 3 of the drawings, each register wheel 23 is formed with a slot or recess 30 at a position corresponding to one of the index positions of each register wheel at which the apex 28 is located in an indentation 25a in the surface 25. At this position, the slot 30 is aligned with one of the pins 22, and when all register wheels have their slots 30 similarly located, movement of the plunger 20 to depress the release knob 12 of the hand brake lever 11 is permitted.

The slots 30 may be formed in the register wheels 23 by any suitable means, such as the provision of a multiplicity of regions of reduced thickness in each wheel 23 which may be broken away to define a slot 30 at any desired indexed position.

The regions of reduced thickness in the wheels 23 which are broken away to form slots 30 are separated from each other by ribs on the outer faces of the wheels, those regions being considerably lower than the ribs 30a so as to minimize the risks of picking the lock. For example, if a force is applied to knob 37 thus urging the pins 22 against the wheels 23, and the wheels 23 rotated, the pins will jump or "click" from one reduced portion to the next over the intervening ribs. Each time this occurs it will feel as though the slot 30 is encountered. The person attempting to pick the lock cannot distinguish between the slot 30 and reduced thickness portion. If too much force is applied to the knob 37, the wheel 23 cannot be rotated as pins 22 engage the ribs.

The register wheels 23 are held in a fixed axial position relative to the second sleeve portion 18 by means of a self locking ring 31 having internal teeth 32 which frictionally engage the periphery of the second sleeve portion 18 to lock each of the register wheels 23 in place. A sleeve 33 is supported about the second sleeve portion 18 and has an internal annular enlargement 34 which co-operates with a split circular clip 35 also located within a groove 36 in the second sleeve portion 18. The plunger 20 is provided at its free end with a skirted actuating cap or knob 37, the skirt 38 of which extends about the sleeve 33. A coil spring 39 is located between the sleeve 33 and the cap 37 to normally bias the plunger to the inoperative position. Since the skirt 38 locates about the sleeve 33, the risk of tampering with the mechanism is reduced, and even should the cap 37 be removed from the plunger 20, access to the register wheels and pins 22 is still denied. The cap 37 and sleeve 33 are formed from nylon to ensure smooth sliding between these parts to prevent jamming with the release knob 12 depressed.

In use the device 10 is located over the hand brake lever 11 of a vehicle and secured thereto in the manner previously described. For normal operation of the hand brake the wheels 23 are rotated so that the slots 30 in the respective wheels 23 are aligned with the respective pins or keys 22 so as to permit longitudinal movement of the plunger 20. thus if the hand brake is to be applied or released the cap 37 is simply depressed so that the plunger 20 acts against the member 12 to depress same in a normal fashion. If, however, the hand brake is to be locked in an "on" position it is normally applied by depressing the cap 37 to depress the release member 12 and pivoting the lever 11 to the locked position, alternatively, depression of the release member 37 may not be required for hand brake application with the lever 11 simply pivoted to an "applied" position. The wheels 23 are then rotated to move the recesses 30 out of alignment with the respective pins 22. this will thereby prevent longitudinal movement of the plunger 20 and prevent release of the hand brake until the wheels 23 are again moved to a position such that their slots 30 are aligned with the pins or keys 22.

To facilitate each access to an operation of the lock, the register wheels 23 are formed with a sloping face 40 terminating in a raised rim 41 having a peripheral diameter slightly greater than the adjacent portion of the first sleeve portion 13 and significantly greater than the peripheral diameter of the sleeve 33 and the actuating cap 37. The sloping faces 40 serve to provide a distinct separation between the rims 41 while the larger diameter of the peripheral portion of the rims 41 compared to the sleeve 33 makes the rims 41 more accessible to the operator.

The rims 41 are each formed with a ribbed surface to increase the ability of the operator to grip the register wheels 23, and locating numbers 42 are formed on the sloping faces 40 of each wheel 23 at positions aligned with the indentations 25a in the recesses 24. An indicator mark 43 is formed on the sleeve portion 13 at a position in alignment with the pins 22 so that when each register wheel is rotated to a position in which the correct number 42 associated with the slot 30 is aligned with the indicator 43, the plunger 20 may be depressed by depressing the cap 37 to operate the button 12 to release the hand brake lever 11.

If it is required to make the hand brake lever 11 a neat fit within the housing 33, a padding material 44 may be located within the housing so as to occupy some of the free space therein, and a metal plate 45 may be located between the bolt 16 and the lever 11 to spread the clamping force provided by the bolts 16 and to reduce damage to the lever 11. In some instances, it may be necessary to remove at least part of the cover of the hand brake lever so as to enable it to be inserted into the housing 13.

The lock 10 may have any number of register wheels 23 although at least two should be provided for greater security of locking. The housing 13 is conveniently made of cast metal resistant to cutting by means of hack saws while the register wheels may be cast from any suitable material such as aluminium.

Claims

CLAIMS:

1. A hand brake lever lock comprising a sleeve adapted to fit over the operative end of a hand brake lever having an release button, means for fixing the sleeve on the hand brake lever, plunger means mounted for reciprocating movement in the sleeve against the action of resilient means for restoring the plunger to its inoperative position, said plunger means engaging in use the release button of the hand brake lever and having an operating cap fixed to its outermost end, combination lock means carried by a portion of the sleeve of reduced dimensions and positioned to prevent movement of the plunger in the locked condition whilst allowing movement of the plunger in the unlocked condition, said combination lock including a plurality of register wheels rotatably mounted on said portion of said sleeve and each adapted to be rotatably indexed to a multiplicity of positions at only one of which the locking means is released, detent means for resiliently restraining the wheels at each of said multiplicity of positions, characterized in that each of said detent means comprises a shaped spring clip having legs which engage said portion of said sleeve, said legs being joined at an apex portion which positively engages indentations formed inside each register wheel at positions corresponding to each of saidpredetermined indexed positions, said legs being formed with opposed inwardly directed indentations intermediate their ends which engage similarly shaped grooves formed in the surface of said sleeve portion, said inwardly directed indentations co¬ operating with said grooves to resiliently slide on a surface of said grooves as the register wheels are rotated from each indexed position whereby the legs of the spring clip are resiliently spread by the camming action of the grooves whilst remaining in close proximity with the sleeve portion thereby providing a more positive detent action at each indexed position whilst avoiding contact between the legs and the register wheels.

2. The lock of claim 1, wherein the legs of said spring clip substantially beyond said indentations closely conform to the surface of the sleeve portion whereby when said legs are cammed apart they remain clear of the register wheel as it is rotated to the next indexed position.

3. The lock of claim 1 or 2, wherein each of said register wheels has a raised operating rim having a peripheral dimension slightly larger than the peripheral dimension of the adjacent portion of said sleeve and larger than the peripheral dimension of the release button whereby the operating rims of said register wheels are more accessible for manual rotation to the desired indexed positions.

4. The lock of claim 3, wherein the rim of each register wheel is separated from the rim of the or each adjacent register wheel to facilitate easier manual rotation of each register wheel without inadvertent rotation of an adjacent wheel.

5. The lock of claim 1 or 2, wherein each register wheel is located on said portion of said sleeve by a washer having inwardly directed teeth which frictionally engage said portion of said sleeve to locate wheel in position.

6. The lock of claim 1 or 2, wherein each register wheel has a slot in said one of said multiplicity of indexed positions, each slot being between a pair of raised ribs formed onto register wheel at each indexed position to deter location of the slot by the application of pressure to the plunger while rotating each wheel, said ribs preventing rotating of each wheel under excessive pressure applied to the plunger.