WO2005019662A1

WO2005019662A1 - Axial locking device and blocking mechanism therefor

Info

Publication number: WO2005019662A1
Application number: PCT/GB2004/002473
Authority: WO
Inventors: Austen Bernard Barnes
Original assignee: Lyndon-Stanford, Edward
Priority date: 2003-08-19
Filing date: 2004-06-10
Publication date: 2005-03-03
Also published as: GB0319473D0

Abstract

A locking device (1) is a female engagement member to which a male engagement member (4) can be locked and then unlocked by axial movement of the male member (4) relative to the locking device (1) and a second movement in the same direction of the male member (4). The locking device (1) has a locking mechanism which includes a slider (5) which is moved by the male member (4) and which causes the locking mechanism to lock the male member (4) and, on a further movement, causes the locking mechanism to unlock the male member (4). A remote control blocking mechanism (7) can prevent full unlocking or locking movement of the slider (5) and thereby prevent the male member (4) being unlocked or locked. The blocking mechanism (7) includes a bi-stable rotary electromagnetic actuator including two circumferentially spaced electromagnets (21, 22) which act on a magnetised rotor (19) fixed to a rotary shaft (16). In one position of the shaft (16) flutes (18) on the end portion of the shaft (16) can pass through a profiled hole (9) in the end cap (8) of the locking device (1) and allow free movement of the slider (5) whereas in another rotary position of the shaft (16), the flutes (18) cannot pass through the profiled hole (9) and the movement of the slider (5) is blocked.

Description

Axial Locking Device and Blocking Mechanism therefor

BACKGROUND

The present invention relates to axial locking devices (also called attachment devices) of the type for locking an engagement member to another engagement member, the engagement members normally being a female engagement member and a male engagement member, the locking device comprising one of the engagement members and a locking mechanism for locking the engagement members together and actuated by relative axial movement of one engagement member relative to the other, the locking mechanism including a moveable actuating member whose movement (which may be translational and/or rotary) is responsive to said relative axial movement of the engagement members, a first movement of the actuating member in one direction causing the engagement members to be locked together and a second movement (normally a repeat movement) of the actuating member in the same direction causing the engagement members to be unlocked. Such axial locking devices are disclosed in FR 2 106 694, US 4 709 454 and US 5 530 999.

Axial locking devices have wide application and their simple locking and unlocking mechanism makes them very easy to use, for instance in any means of transport. In or on motor vehicles, they can be used for mounting for instance night parking reflectors, emergency lights, infra-red illuminators, video scanners, towing hawsers, and, as travelling aids for children, drink-holders, TV holders, food tray supports and video game holders, and also camping items. However, one disadvantage is that the great ease of unlocking can lead to unauthorised or inadvertent unlocking.

It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. Any discussion of the prior art throughout the specification is not an admission that such prior art is widely known or forms part of common general knowledge in the field.

THE INVENTION

In its broadest aspect, the present invention provides an axial locking device as set forth in Claim 1.

In operation, the blocking mechanism can be connected to command means remote from said activating and deactivating means, which command means can activate the activating and deactivating means to cause them to prevent the engagement members being unlocked or locked and can deactivate the blocking mechanism to permit the engagement members to be unlocked or locked. Thus the command means need not be attached to the axial locking device except through say the body or chassis of a vehicle though the command means could be fairly close to the locking device, say if the locking device is a panel fastener enabling an item to be plugged into one side of the panel and the command means is on the other side of the panel.

The blocking mechanism adds greatly to the usefulness of the locking device. In a simple manner, the blocking mechanism holds the axial locking device in its current locked or unlocked position, and the blocking mechanism can for instance be controlled from the vehicle cab, say by a dashboard push-button with another push-button provided to restore normal axial locking device function. Thus a push of the button can prevent unauthorised removal or addition of components. The blocking mechanism can be designed as a low-cost retrofit add-on to existing axial locking devices, for instance being a snap-fitting on the end of, or over the side of, the locking device. The arrangement can be such that only minor modifications to existing locking devices are necessary with no additional internal parts, and the so modified locking devices will operate normally and can be interchangeable with normal locking devices for normal use. The blocking mechanism can be bi-stable. The blocking mechanism may be an electromagnetic mechanism, or could alternatively be of any suitable sort, such as mechanical, pneumatic pressure operated, vacuum operated or hydraulically operated (i.e., in general using fluid operation), and for special mechanisms, piezo electric or magnetostrictive operation is feasible in spite of the short travel length and high cost.

If the blocking mechanism is electromagnetic, it can have two input wires, blocking the locking device if one input wire is energised and freeing the locking mechanism if the other wire is energised. When using fluid operation, it is possible to use a two-port mechanism or a single-port mechanism with a spring return. The motion transfer can be by linkage, splines, rotary cams or slide cams, wound spring, rack and pinion, and any suitable mechanism, and the prime mover can be for instance a piston, a diaphragm, a 90° moving vane, an expandable tube, or bellows. A double-port mechanism could be used and remain stable after the removable of the signal pressure or vacuum if fitted with magnetic holding stabilisation at the end of the actuation movement. A single-port mechanism with a spring return would need a maintained signal for "on" with no signal for "off, or vice versa. Alternatively, a single port or single wire pulsed single operation can be used in conjunction with a binary counter device giving alternating "on" and "off output.

The means for associating the activating and deactivating means with the command means are not limited to electrical or fluid operated means; for instance, sonic or infra-red detectors or radio could be used.

The moveable actuating member of the locking device can have axial movement and/or rotary movement. The blocking mechanism can block the axial movement, for instance adjacent one end of the stroke, and/or can block the rotary movement.

The dependant claims claim preferred or optional features of the locking device. The invention extends to the axial locking devices of the drawings, to the blocking mechanism for the axial locking device and to a means of transport having mounted thereon the axial locking device and the actuator. PREFERRED EMBODIMENTS

The invention will be further described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a side view of an axial locking device with a first blocking mechanism;

Figure 2 is an end view of the locking device, showing the modifications made to accommodate the first blocking mechanism;

Figure 3 is a view of the locking device and blocking mechanism, mainly in axial section;

Figure 4 is a transverse section along the plane IV-IV in Figure 3;

Figure 5 is a view, mainly in section along the line V-V in Figure 6, of the axial locking device with a second blocking mechanism;

Figure 6 is an end view of the locking device and the second blocking mechanism, in the direction of the arrow VI in Figure 5;

Figure 7 is a view, partly in section along the line VII- VII in Figure 5, of the locking device and the second blocking mechanism;

Figure 8 is an outside view, looking in the direction of the arrow VIII in Figure 6, of the locking device and the second blocking mechanism;

Figures 9a, 9b and 9c show three different arrangements for activating the second blocking mechanism;

Figure 10 schematically shows a blocking mechanism with a remote actuator. Both embodiments show the female part of the locking device 1 (incorporating the female engagement member) fixed to a vehicle bulkhead 2 using a collar 3. This is purely by way of example and the locking device 1 can be used in any suitable way.

Figures 1 to 4

Figure 1 shows an axial locking device 1 as described with reference to Figures 1 to 3g of US 5 530 999, which is incorporated herein by reference and to which reference should be made for a detailed description of the components and operation of the locking device 1. The locking device 1 has a locking mechanism which locks and unlocks a male engagement member 4 to and from a female engagement member defined by the locking device 1. The male member 4 may have a threaded position 4a and a hexagonal socket 4b in its front end for accepting an "Allen" key, for screwing the male member 4 into a threaded hole. The locking mechanism includes an actuating assembly which comprises an axially movable actuating member in the form of a slider 5a and an axially movable and rotary actuating member in the form of a cam 5b, which assembly 5 a, 5b is moved by the male member 4 on inserting the male member 4 into the locking device 1 and is moved back in the opposite direction by means of a spring 6 (shown faint in Figure 3). When the male member 4 is inserted, it causes a first movement of the assembly 5a, 5b to the right which in turn, as explained in US 5 530 999, causes the male member 4 to be locked into the locking device 1 though the spring 6 will after the first movement cause some retraction of the male member 4 and of the assembly 5 a, 5b. On a second movement to the right of the male member 4, the assembly 5 a, 5b is again moved to the right and causes the male member 4 to be unlocked from the locking device 1.

The male member 4 is shown in its locked position in Figure 3. For clarity, the only internal components shown of the locking device 1 are the slider 5 a, the cam 5b and the spring 6.

In order to modify the locking device 1 to receive a blocking mechanism 7, the end cap 8 of the locking device 1 is formed with a profiled hole 9 (a circular hole with diametrically opposed "niches") and a rectangular slot 10. The right-hand end of the slider 5 is machined with, or already has, a circular hole 11.

The blocking mechanism 7 has a housing 12 which snaps on to the right-hand end of the locking device housing 13 and is retained by tines 14 which engage in a circumferential depression in the housing 13 and provide the correct axial location of the blocking mechanism 7. The end cap 8 is swaged and retained in position. The blocking device 7 has a tang 15 (see Figure 4 - described later) which fits into the slot 10 and provides the coπect rotational orientation of the blocking mechanism 7.

The blocking mechanism 7 includes an axial shaft 16 mounted for rectilinear movement and sliding in a sleeve bearing 17 at its right-hand end - the bearing 17 is riveted to the end of the housing 12. The left-hand end of the shaft 16 fits into the hole 11 formed in the right-hand end of the slider 5a, which forms a bearing for the left-hand end of the shaft 16. Adjacent its left-hand end, the shaft 16 has radial projections in the form of flutes or wings 18 (see Figure 3) which can pass through the "niches" of the profiled hole 9 in the end cap 8. Thus in one rotary position, the shaft 16 can move freely through the profiled hole 9 and in another rotary position, it is blocked by the end cap 8.

To provide activating and deactivating means for the blocking mechanism 7, the shaft 16 carries a rotor 19 which is transversely magnetised as indicated by the N,S in Figure 4. If desired, a weak helical or tapered compression spring 20 is provided biasing the shaft 16 to the left, though this is not essential in all arrangements, as described below. The rear face of the rotor 19 is recessed to entrap the spring 20, and this also provides a longer stroke in that the right-hand end of the rotor 19 can pass over the outside of the bearing 17 while maintaining enough bearing length to maximize the support of the shaft 16.

Two electromagnets 21, 22 are formed by cores 23, 24 which carry stator windings 25, 26. The cores 23, 24 protrude through to the outside of the housing 12 and can be e.g. peened or riveted in position. The magnetisation of the cores 23, 24 is indicated as NI, SI and N2, S2. The cores 23, 24 hold in position a common electromagnetic yoke strip 27 which embraces the electromagnets 21, 22 and, on the opposite side of the axis to the electromagnets 21, 22, passes close to the magnetised rotor 19, as can be seen in Figure 4. The yoke strip 27 assumes an opposite plurality to the inner face of the energised cores 23, 24.

As shown in Figure 4, the electromagnets 21, 22 are circumferentially spaced about the axis, their centre lines being separated by 105° to allow space for the windings 25, 26, but the ideal separation is 90° though the separation could be as low as about 70° and as high as about 110°.

The energisation of one electromagnet 21, 22 or the other causes the rotor 19 and shaft 16 to assume one of two different rotary positions according to which electromagnet 21, 22 is energised, Figure 4 illustrating the position when the electromagnet 21 is energised. The angle of rotation of the shaft 19 is the same as the circumferential spacing of the electromagnets 21, 22. The electromagnets 21, 22 are energised by DC pulsing, e.g. with a 250 ms pulse. One end of each winding 25, 26 can be common and can either be grounded (earthed) to the housing 12 or connected to a cable connector 28. The cable connector 28 is soldered or bonded in position and is shown as having connectors for the active connections of the windings 25, 26. In this way, the electromagnets 21, 22 provide a rotary bi-stable magnetic circuit settable in one of two states by alternate DC pulsing of the windings 25, 26. The magnetised rotor 19 stays aligned with the last of the electromagnets 21, 22 to be energised and is lightly retained in that position by the magnetic attraction between the respective core 23, 24 and the rotor 19.

When (as described below) the shaft 16 moves to the right, the centre of the magnetised rotor 19 will be to the right of the centre position of the electromagnets 21, 22. The energised electromagnet 21, 22 will tend to draw the core 18 to the left. Thus in a short stroke unit, the spring 20 is not necessary, though it is desirable in a long stroke unit.

The tang 15 (referred to above) projects axially from the yoke strip 27 into the slot 10 and sets the radial location of the inner face of the yoke strip 27 to obtain the correct gap between the yoke strip 27 and the magnetised rotor 19, as well as providing the correct rotational orientation of the blocking mechanism 7, as mentioned above.

Assembly

For assembly, the blocking mechanism 7 is preset by energising the electromagnet 21. The slider 5 is pushed to the right and the blocking mechanism 7 is rotated so that its locator tang 15 aligns with the slot 10 in the end cap 8. The shaft 16 is inserted through the profiled hole 9 and the shaft left-hand end locates in the hole 11 in the right-hand end of the slider 5. The blocking mechanism 7 is snapped home.

Operation

In this rotary position (the first state of the blocking mechanism 7), the slider 5a can push the shaft 16 to the right and thus the male member 4 can be locked to and unlocked from the locking device 1. When the electromagnet 22 is energised, the shaft 16 rotates and the flutes 18 are mismatched with the profiled hole 9 (the second state of the blocking mechanism 7) so that when the slider 5 a is pushed to the right, the flutes 18 prevent further movement of the shaft 16, the slider 5a is blocked and the male member 4 cannot be locked or unlocked. When the electromagnet 21 is energised, the shaft 16 rotates to its original position, the flutes 18 will pass through the profiled hole 9 and the male member 4 can be locked or unlocked. The magnetised rotor 19 will remain aligned with the last electromagnetic pole 23, 24 to which it was attracted.

Figures 5 to 10

Figures 5 to 10 show a side mounting blocking mechanism 29.

One method of assembly to the attachment device shown in Figures 5 and 6 uses a sleeve 30 with longitudinal slide slots at 31 on opposite sides slightly off centre. Left- hand and right-hand slots 31 are provided, giving four point engagement. The sleeve 30 also has a tongue 32, which enables it to snap over the locking device casing 13, providing a locked axial and angular position. The housing 33 of the blocking mechanism 29 can then snap onto the sleeve 30 by four tines 34 (see Figure 8) engaging in the slots 31. As shown in Figure 8, the housing 33 is slit on each side to provide skirts 33a which pass over the wider end of the sleeve 30, and also to provide balanced resilience for the tines 34.

The interior of the blocking mechanism 29 is shown in Figure 5. A stubshaft 35 of non-magnetic material such as bronze or stainless steel is free to slide axially with limited movement. To provide activating and deactivating means for the blocking mechanism 29, the stubshaft 35 mounts a rigidly attached permanent magnet disc 36, radially magnetised with for instance the inner diameter south and the periphery north, with opposite poles at 37 and 38. Engaging the disc 36 but with an air gap are two annular electromagnets 40 and 41. These have annular grooves in which are mounted energising coils 42 and 43. As described later, these may be single coils or each can be a dual coil.

The electromagnets 40 and 41 are mounted in an annular or toroidal cage 44 which is shaped to support the electromagnets 40 and 41 in exact alignment. The cage 44 is formed as two half shells split horizontally (as seen looking at Figure 5) along a plane containing the axis of the stubshaft 35, and pushed together at assembly to entrap and support the electromagnets 40, 41. Extensions at 45 and 46 set the cage 44 relative to the housing 33, which is equipped with a spacer 47. The spacer 47 and extensions 45 and 46 abut the wall of the sleeve 30, setting the electromagnet yoke assembly exactly oriented relative to the locking device 1. The arrangement shown is an example of many ways of achieving satisfactory relative orientation.

Connections to the electromagnets 42 and 43 are routed to a cable connector 28 via the channel afforded by a spacer tab 47.

The coils 42, 43 electromagnets 40, 41 and permanent magnet 36 need not be disc shaped as described, but can be oval or rectangular to suit the needs of the blocking mechanism 29 or locking device 1. To obtain the alternate attract/repel polarity there are three choices of coil arrangement, as shown in Figures 9a to 9c.

The two coils 42, 43 can be simple single coils connected in series or parallel and an applied direct cuπent can be alternately pulsed forward or reversed to attain repulsion by one coil 42, 43 and electromagnet 40, 41, and attraction by the other. Such an arrangement is stable and remains set to the state of the last pulse.

Alternatively, the coils 42, 43 can each be split wound (centre tapped) with three connections each. The center tap on each can be grounded (earthed) or common, and one or the other outer tap can be alternately connected to positive to obtain reversed magnetic polarity. At any given time, only half of each coil 42, 43 is used. The outers taps of each coil 42, 43 are joined to give opposite polarity when energised relative to the common.

The stubshaft 35 is provided with a tongue 48 as shown in Figures 5 and 7. When the stubshaft 35 moves down, its tongue 48 enters a slot 49 in the walls of the sleeve 30 and casing 13 and extends further, which prevents full axial movement of the slider 5a and cam 5b which move in unison as the locking device attachment or detachment action commences. This movement prevention blocks the locking device 1, engaging from one side only the cam 5b and not engaging the slider 5a.

Assembly

The extension 45 keeps the tongue 48 in the correct rotative orientation prior to unit assembly. The blocking mechanism 29 is assembled onto the locking device 1 by first installing the sleeve 30, snapping it over the locking device 1 with tongue 32 locating it. The entire blocking mechanism 29 is then moved downwards, allowing the tongue 48 to enter the slot 49, and allowing tines 34 to snap onto the sleeve 30.

Operation The electromagnets 40 and 41 can be arranged by appropriate energisation of coils 42 and 43 to alternately attract and repel the permanent magnet 34, causing the stubshaft 35 to move with high force to the upper position (first state of the blocking mechanism 29), or return to the lower position (second state of the blocking mechanism 29) shown in Figure 5.

Fluid Operation

The electromagnetic actuator as described can be directly replaced in linear operation of the stubshaft 35 and tongue 48 by a double-acting cylinder operated by air, vacuum, or hydraulic means.

Remote Command Means

Figure 10 schematically illustrates remote command means in the form of a remote actuator 61 connected to the blocking mechanism 7 or 32. The remote actuator 61 can just be in the form of two push buttons on a vehicle dashboard, connected as appropriate to the cable connector 28 by a cable 62.

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise" and the like are used in an inclusive as opposed to an exclusive or exhaustive sense, that is to say, in the sense of "include, but not limited to".

The present invention has been described above purely by way of example, and modifications can be made within the spirit of the invention. The invention also consists in any individual features described or implicit herein or shown or implicit in the drawings or any combination of any such features or any generalisation of any such features or combinations. Each feature disclosed in the specification, including the claims, abstract and drawings, may be replaced by alternative features serving the same, equivalent or similar purposes, unless expressly stated otherwise. It is possible that the blocking mechanism could be designed for other locking devices not actuated by relative axial movement of engagement members and/or in which a first movement of the actuating member in one direction causes locking and a second movement in the same direction causes unlocking and/or not having a moveable actuating member whose full unlocking or locking is prevented by the blocking mechanism.

Claims

CLAIMS:

1. An axial locking device for locking an engagement member to another engagement member, and comprising: a said engagement member; a locking mechamsm for locking the engagement members together and actuated by axial movement of one engagement member relative to the other, the locking mechanism including a movable actuating member whose movement is responsive to said relative axial movement of the engagement members, a first movement of the actuating member in one direction causing the engagement members to be locked together and a second movement of the actuating member in the same direction causing the engagement members to be unlocked; a blocking mechanism, the blocking mechanism having a first state in which it does not prevent full unlocking or locking movement of the actuating member, thereby permitting the engagement members to be unlocked or locked by said relative axial movement, and a second state in which it prevents full unlocking or locking movement of the actuating member, thereby preventing the engagement members being unlocked or locked by said relative axial movement; means for activating the blocking mechanism to change it from said first state to said second state and for deactivating the blocking mechanism to change it from said second state to said first state; and means for associating said activating and deactivating means with command means, for changing the blocking mechanism from said first state to said second state or from said second state to said first state.

2. The locking device of Claim 1, wherein said activating and deactivating means are actuated electromagnetically.

3. The locking device of Claim 2, wherein the blocking mechanism includes a permanently magnetised rotor mounted for rotary movement about an axis and two electromagnets which are circumferentially spaced about said axis, the energisation of one electromagnet or the other causing the rotor to assume one of two different rotary positions according to which electromagnet is energised.

4. The locking device of Claim 3, wherein a magnetic circuit is formed by a ferromagnetic member which embraces the electromagnets and, on the opposite side of the axis to the electromagnets, passes close to the permanently magnetised rotor.

5. The locking device of Claim 1, wherein the blocking mechanism is actuated by a fluid.

6. The locking device of any of Claims 1, 2 or 5, wherein the blocking mechanism is bi-stable.

7. The locking device of any of the preceding Claims, and comprising a shaft mounted for rectilinear movement and arranged to engage the actuating member to prevent full locking or unlocking movement thereof when the shaft is in its blocking position, the shaft having at least one radial projection and the shaft passing through an opening in a fixed transverse member which has a cut-out corresponding to the radial projection so that when the shaft is in an unblocking rotary position, it can move freely through the transverse member and when it is in a different, blocking rotary position, it is blocked by the transverse member, the shaft being connected to the blocking mechanism so that the blocking mechanism can rotate the shaft between its unblocking position and its blocking position, whereby when the shaft is in its unblocking rotary position, the radial member can pass through the transverse member and permit the shaft to move axially and permit the actuating member to move and cause the engagement members to be locked or unlocked, and when the shaft is in its blocking rotary position, the radial projection engages the transverse member and prevents full movement of the shaft and hence full unlocking or locking movement of the actuating member.

8. The locking device of Claim 1, wherein the shaft is biased towards the actuating member.

9. The locking device of any of the preceding Claims, wherein the actuating member is axially moveable and the blocking mechanism prevents full unlocking or locking axial movement of the actuating member.

10. The locking device of both Claim 7 and 9, wherein the shaft is mounted for rectilinear movement parallel to the movement of the actuating member.

11. The locking device of Claim 10, wherein the transverse member is an end closure of the locking device.

12. The locking device of any of Claims 7 to 11, wherein the blocking mechanism is as in Claim 3 or 4, the permanently magnetised rotor being fixed to said shaft.

13. The locking device of Claim 1 or 2, and including a blocking member which can move at right angles to the direction of movement of the actuating member, to be engaged by the actuating member and prevent full unlocking or locking movement of the actuating member, the blocking member being movable by the blocking mechanism between a position in which it is engagable by the actuating member and a position in which it is not engagable by the actuating member.

14. The locking device of Claim 13, wherein the actuating member is axially moveable and the blocking mechanism prevents full unlocking or locking axial movement of the actuating member.

15. The locking device of Claim 13 or 14, wherein to provide said activating and deactivating means, the blocking member carries a permanent magnet which is movable adjacent at least one electromagnet which can be energised to move the permanent magnet from one end position in which the blocking mechanism is in said first state to another end position in which said blocking mechanism is in said second state.

16. The locking device of Claim 15, wherein the permanent magnet is a disc which is magnetised radially so as to have an annular pole adjacent in its periphery and another annular pole adjacent the blocking member, the electromagnet providing corresponding annular poles.

17. The locking device of any of the preceding Claims, wherein the blocking mechanism is formed as an initially separate device for fixing to the locking device.

18. The locking device of Claim 17, wherein the fixing is a snap fixing.

19. The locking device of Claim 18 when read as appendant to any of Claims 1 to 12, wherein the blocking mechanism comprises a mounting member which makes a snap-fit over an axial end of the axial locking device remote from said engagement members by relative movement of the blocking mechanism mounting member in a direction parallel to the axis of said relative movement of said engagement members.

20. The locking device of Claim 18 when read as appendant to any of Claims 13 to 16, wherein a sleeve is placed over and locked to a casing of the axial locking device and the blocking mechanism comprises a mounting member which snap-fits over the sleeve by relative movement of the blocking mechanism mounting member in a direction radial to the axis of relative movement of said engagement members.

21. The locking device of any of the preceding claims, wherein said associating means are for associating said activating and deactivating means with command means which are not directly fixed to the locking device or blocking mechanism.

22. The locking device of any of Claims 1 to 20, wherein said associating means are for associating said activating and deactivating means with command means remote from the locking device.

23. An axial locking device having a remote control blocking mechanism, substantially as herein described with reference to Figures 1 to 4 or Figures 5 to 9 of the accompanying drawings.

24. The locking device of any of the preceding Claims, with the activating and deactivating means connected to command means which can activate the blocking mechanism to cause it to prevent the engagement members being unlocked or locked and can deactivate the blocking mechanism to permit the engagement members to be unlocked or locked.

25. A blocking mechanism for an axial locking device for locking an engagement member to another engagement member and comprising a said engagement member and a locking mechanism for locking the female engagement member to the male engagement member and actuated by axial movement of the engagement members relative one to the other, the blocking mechanism being as set forth in any of Claims 1 to 23.

26. A means of transport such as a motor vehicle, having mounted thereon the axial locking device and actuator of Claim 24.