AXIAL LOCKING DEVICE

Abstract: An axial locking device has two separable members (1, 2) which can be locked together and unlocked by relative movement of the two members in one axial sense. Locking and unlocking are effected by a cam slider (8) which can rotate and move axially. The cam slider (8) has flexible teeth (43) which can engage reaction teeth (44), and wave-form teeth (42), which can engage complementary teeth (41). On pushing the member (2) to the left, a toothed ring (3) causes the teeth (43) to apply rotary biassing to the cam slider (8) which causes the teeth (41, 42) to jump by one pitch, giving a click. The click indicates that the device is locked.

Description: AXIAL LOCKING DEVICE Background of the Invention The present invention relates to an axial locking device for locking together and unlocking two separable members by relative movement of the two members in one axial sense. This permits one-handed and/or speedy operation of the locking device. One such axial locking device is disclosed in US 4 709 454. The two members are locked together when they are first pushed together, and are then unlocked when they are subsequently pushed together. No relative rotary movement is required between the two members. The axial locking device should be able to resist tensile loads unrelated to the axial force required to operate the locking device. The locking device can be designed to be strong in the canting mode, ie there is very little lateral backlash, and the device can resist high transverse loads. The invention is in general applicable to axial locking devices with the locking mechanism mounted on the male member or on the female member. The two separable members which form the device will be arranged for connection to the elements which must be coupled together, or at least one of the members could be or form part of the element itself. The part of the second member which is engaged by the locking element of the locking member, and the part of the second member which engages the actuating means of the locking mechanism, need not be integral with each other, provided they are suitably secured to the second member. In general, it is desirable to make the manufacture less expensive. It is also desirable to avoid a situation in which the relative movement has been insufficient to lock the members properly together. The locking device of the invention can permit instant fastening or disconnection of for instance hoses, cables, electrical connectors, sub-assemblies, panels, wires or mounting brackets, and can be used for instance for small oil pipeline connectors (for instance which cannot be opened with the pressure on), sewage plant aerator connectors, instrument flexible coupling connectors, medical life support connectors, back connectors for gas meters, swimming pool connectors or many connectors for an automobile engine. There is no relationship between operating force and the strength of the locking device. The locking devices can be attached or detached in blind locations without access, and are thus suitable for making connections in confined spaces. As the movement is axial, with no rotation, actuation is easily accomplished by disabled persons or simple robotics, and single-handed operation is normal. The locking device can be fast, inexpensive and simple. The Invention A first aspect of the invention provides an axial locking device for locking together and unlocking two separable members by relative movement of the two members in one axial sense, the device comprising a locking mechanism which is associated with a first of the members, the locking mechanism comprising means for causing a click action to occur as the locking mechanism is partly or fully actuated. A plurality of clicks may be required before locking. Pull actuation is not necessary for a click to occur, as long as either there is locking or the return motion (in the opposite sense) will cause locking. Preferably, there is a click which is audible, but it is possible to arrange for the impulse or vibration from the click to be sensed through one of the members which is held in the hand. In this way, the click signifies to the operator that the operating point has been reached. The term "click" is used herein to include any suitable impact or mechanical release giving rise to an audible sound or an impulse (tactile feed-back) that can be physically sensed - the action may be describable as a snap action; thus the term "click" includes equivalent sounds. In a specific arrangement for obtaining the click action, there is a toothed sliding actuating member, • which when moved axially interfaces with a toothed rotary locking member such that as the actuating member teeth move axially, they lift the locking member from its rest position against retaining means fixed to a housing of the device, and thereby cause rotation of the locking member when lifted clear of the retaining means, rotating to engage with the actuating member teeth. This gives a click action. As the actuating member is then relaxed and allowed to return to the normal position, spring means, eg a single spring, pushes back the locking member slider, causing it to further rotate through one full tooth, so that the teeth again engage with the retaining means. Alternatively, the retaining means can be located on the first member, and the moving teeth located on the housing, such that movement of the housing relative to the two members causes operation of the locking mechanism. The click action can be obtained in other ways. In one way, a toothed rotor fixed to the locking means moves axially.and rotates between two facing rings of teeth, each sprung biased towards the rotor. In another way, the rotary movement of the locking means is arranged to detent by virtue of the locking means interfacing with a suitable tooth form on the housing, and as a spring force on the locking means overcomes the restraint of the tooth form, the locking means jumps, giving a click action. The tooth form need not be wavy, but this is the preferred form. In a further way, engagement of the two members causes toothed locking means to move axially against spring force, relative to the housing, thereby causing its teeth to interact with teeth on the housing and so impart rotation of the locking means as its teeth precess, ie as they engage one set and then the other set of teeth in the housing. The spring can be single or multiple, with at least one of the spring elements arranged to have a partially bi-stable action or click action as it moves to its complete excursion, thereby imparting a click action to the operation of the locking mechanism. The locking means preferably comprises an angularly movable locking member, which may be both axially and angularly movable with respect to the first member. The preferred arrangement is for the locking means to comprise a rotary cam slider which is rotated eg by interengaging teeth, a one tooth excursion changing the cam profile to offer alternate high and low points of the cam to at least one locking element which is inserted into or retracted from a recess or groove 01. other detent located in the second member, thus alternately locking and unlocking the device with alternate cycles of the relative axial movement of the two members in said one sense. In other arrangements, the locking element need not be a part separate from the locking means. The slider is preferably mounted on or incorporated in one of the members so that it moves relative to the member against spring means when said relative movement of the two members occurs. The slider is displaced in one angular direction by interengagement of mutually-engageable teeth on the one member and on the slider, each time the slider is moved axially. This angular displacement of the slider locks the two members together when they are first pushed axially together against the force exerted by the spring means, and then unlocks the two members when they are subsequently pushed axially together against the spring force. In general, the device may comprise means which, on said relative movement of the members, bias the locking mechanism towards actuation, and retaining means which prevent actuation of the locking mechanism until said relative movement has occured, the retaining effect then being released with a click. The locking mechanism preferably comprises: a locking element for engaging the second member to lock the members together; actuating means moveable with respect to the first member and engageable by the second member when said relative movement occurs, to initiate actuation of the locking mechanism; locking means which are relatively angularly moveable to actuate the locking element; first angular thrust means; second angular thrust means which co-act with the first angular thrust means and are substantially fixed in an angular sense with respect to the locking means; retaining means which are substantially fixed in an angular sense with respect to the first angular thrust means; the arrangement being such that on said relative movement of the members, the first and second angular thrust means will be in engagement with one another, and the first and/or second thrust means will move axially with respect to the retaining means whilst the retaining means initially prevents relative angular movement of the second angular thrust means and then allows relative angular movement of the first and second angular thrust means, with a click action. The locking means preferably comprise an element which is rotatable about the axis of the locking device. The relative angular movement of the first and second angular thrust means is preferably arrested by the engagement of the second angular thrust means with the first angular thrust means, and on relative movement of the members in the opposite sense, the first angular ' thrust means disengage the second angular thrust means and allows further relative angular movement of the first and second angular thrust means. The first angular thrust means and/or the second angular thrust means preferably comprises teeth with inclined ends, the inclined ends providing the angular thrust. The retaining means are preferably teeth with inclined ends; the teeth of the first angular thrust means, second angular thrust means or retaining means preferably have flanks which are substantially parallel to the axis of the locking device. The ends of the teeth may be formed by a surface at an angle to the flanks and meeting the flank at a point as seen in section; however in another construction, the first angular thrust means have radiussed edges at their ends and the second angular thrust means are of Vee shape formed by surfaces inclined to the axial direction; the ends of the first angular thrust means can be at a large angle, e.g. 70', to the axial direction; the retaining means can be partly or wholly offset radially from the first angular thrust means and be of Vee shape formed by surfaces inclined to the axial direction, preferably alternate ones at the same angle as the corresponding surface on the second angular thrust means and the intervening ones at a greater angle to the axial direction than the corresponding surface on the second angular thrust means, and the intervening surfaces also acting as angular thrust means when co-acting with the second angular thrust means. The first angular thrust means are preferably substantially fixed in an angular sense with respect to the actuating means. The actuating means preferably can move axially relative to the first member, but are preferably substantially fixed relative to the first member in the angular direction. The retaining means are preferably fixed to or integral with the actuating means. The first angular thrust means may be fixed to or integral with the first member, or the retaining means may be fixed to or integral with the first member, in which case the first angular thrust means may be fixed to or integral with the actuating means. The retaining means preferably initially abut the second angular thrust means during said axial movement of the angular thrust means. The angular relative movement between the first and second angular thrust means is preferably powered by spring means which are compressed on said relative movement of the members; the spring means may apply axial biasing between respective elements axially fixed to the retaining means and the second angular thrust means. In one arrangement, the first angular thrust means comprise a first ring of teeth fixed to the first member, between or adjacent which can axially slide the retaining means which comprise a second ring of teeth fixed to the actuating means, the teeth of both said rings facing a third ring of teeth fixed to the locking means for co-acting with the teeth of the first and second rings, all the teeth having substantially the same circumferential pitch. In another arrangement, the first angular thrust means comprise a first ring of teeth fixed to the actuating means, which can axially slide between or adjacent retaining means comprising teeth of a second ring fixed to the first member, the teeth of the first and second rings facing teeth of a third ring fixed to the locking means, for co-acting therewith. The first angular thrust means are preferably biased in the sense opposite to said axial movement of the first and second angular thrust means, which biasing causes the first angular thrust means to move axially on said relative movement of the first and second angular thrust means. The second angular thrust means may be moved axially directly by the actuating means. The second angular thrust means are preferably on one axial face of an axial moveable element, the retaining means being provided on or adjacent the opposite axial face of the axially moveable element, which retaining means themselves act as angular thrust means on movement of the first and second members in said opposite sense whilst said first and second angular thrust means initially prevent relative angular movement of the retaining means, and then allow relative angular movement of the retaining means, with a click action. The said retaining means may comprise a part which is angularly fixed but axially moveable and is biased in the same sense as said axial movement of the first and second angular thrust members, which biasing causes said part to move axially on said relative angular movement of the retaining means. The biasing may be formed by providing the respective angular thrust means or retaining means in a ring on an annular element whose other end is fixed, there being cut-outs between the ring and the other end to provide springing. The device may comprise first and second rings of teeth facing one and other with a gap therebetween, the rings of teeth being biased towards one and other and being rotationally fixed relative to the first member, and, between the first and second rings, a rotatable and axially moveable element which is axially fixed to the acutating means and has on opposite axial faces third and fourth rings of teeth co-acting with the first and second rings of teeth. In a different arrangement, the click action is provided by a click action spring which is actuated on the relative movement of the two separable members. The spring is preferably a dished spring co-axial with the device. There may be a single spring, which serves to spring-bias the locking mechanism, or there may be a further spring for biasing the locking mechanism. The device can comprise further means for actuating the locking mechanism to unlock or to lock and unlock the device without relative movement of the two separable members. The further actuating means may comprise a slider for moving the first and/or second angular thrust means axially with respect to the retaining means. For instance, the further actuating means may comprise a further ring of teeth whose teeth are between respective teeth of the first ring and of the second ring. In US 4 709 454, the locking mechanism has biasing in order to cause it to perform. In a general sense, the biasing need not be spring biasing, but this has been found to be the only practicable means. A second aspect of the invention provides an alternative form of spring biasing which is less expensive to manufacture and assemble, using at least one sprung projecting element arranged such that when the relative movement occurs between the members, the spring element is deflected and locking means are caused to move angularly. Although the element could be sprung by a separate spring, the springing is preferably inherent in the element itself. This aspect of the invention provides a very simple mechanism, which basically need only comprise (in addition to the two separable members) a cam slider and a locking element actuated by the cam slider. The device may comprise detent means which detain the locking means when they have been moved angularly; the detent means comprise the first and second parts referred to above, the force in an angular direction being applied by the sprung element. Reaction means engageable with the sprung element may be substantially fixed with respect to the actuating means in an axial sense, and the angular thrust means may be substantially fixed to the locking means in an angular sense. If the angular thrust means are axially between and are axially moveable relative to the reaction means and a first part of the detent means, the first part of the detent means may cooperate with the second part of the detent means on one end of the angular thrust means, the sprung element being on the other end of the angular thrust means. Said parts of the detent means may comprise respective sets of interengagable elements, at least one set being of wave form. The angular thrust means may be axially moveable relative to the first separable member and the actuating means move the angular thrust means. The reaction means may comprise a toothed ring in which the distal end of the sprung element engages, in which case, the angular thrust means may comprise a plurality of the sprung elements, in a ring. The device can include angular thrust means which are rotatable about the axis of the locking device and act as the locking means. The sprung element or elements preferably act as the sole biasing means of the device. The sprung element may be inclined to the axis of the locking device and to the direction of movement of the locking means; alternatively the sprung element may comprise a generally U shape, the limbs of the U being moveable towards and away from each other to provide at least part of the springing. The sprung element may be of generally circular section. A third aspect of the invention provides a device in which locking means comprise a sleeve, provides a simpler arrangement of the parts of the mechanism. There may be a further, helical spring extending co-axially with the locking means sleeve, for instance in a counterbore in the sleeve. The aspects of the invention can be combined. The locking device as manufactured, stored or sold may or may not include the second member. The invention further consists in the locking device substantially as described with reference to, and as shown in, any of the Figures of the accompanying drawings. Preferred Embodiments The invention will be further described, by way of example, with reference to the accompanying drawings, in which: - Figure 1 is an axial section through a first embodiment of the invention; Figure 2 is a view of part of the cam slider, looking in the direction of the arrow II in Figure 1; Figures 3^ to 3d illustrate four stages in the operating sequence of the embodiment of Figure 1; Figure 4 is a transverse section through a second embodiment; Figures 5^ to 5d illustrate four stages in the operating sequence of the embodiment of Figure 4; Figure 6 is an axial section through a third embodiment of the invention; Figure 7 is a view of Figure 6, corresponding to Figure 3a_; Figure 8 is an axial section through a fourth embodiment of the invention; Figures 9a to 9d illustrate four stages in the operating sequence of the embodiment of Figure 8; Figure 10 is an axial section through a fifth embodiment of the invention; Figures 11a and lib illustrate two stages in the operating sequence of the embodiment of Figure 10; Figure 12 is an axial section through a sixth embodiment of the invention; Figures 13a. to 13d illustrate four stages in the operating sequence of the embodiment of Figure 12; Figure 14 corresponds to Figure 13 but shows a different shape of the detent teeth; Figure 15 is an axial section through a seventh embodiment of the invention; Figure 16 is an axial section through an eighth embodiment of the invention; Figure 17 is a view of Figure 16, corresponding to Figure 13a_; Figures 18 and 19 illustrate two shapes for sprung elements; Figure 20 is an axial section through a ninth embodiment of the invention; Figures 21a_ to 2l£ illustrate three stages in the operating sequence of the embodiment of Figure 20 (or of Figure 22); Figure 22 is an axial section through a tenth embodiment of the invention; Figure 23 is an axial section through an eleventh embodiment of the invention; Figures 24 and 25 illustrate two alternative locking members, in isometric projection; Figures 26a. and 26b illustrate a fourth locking member arrangement, when locked and when unlocked; Figures 27 and 28 illustrate, in isometric projections, two ways of providing the locking member arrangement of Figures 26a_ and 26b; Figure 29 illustrates a use of the invention. In Figures 1, 6, 15, 16, 20, 22 and 23, the cam slider is shown in different angular positions in the upper and lower halves, the upper half being shown unlocked and the lower half locked. The same references are normally used for items having the same or similar functions. Features of one embodiment can be combined if appropriate with features of another embodiment. Figures 1 to 3d In the embodiment of Figures 1 to 3d, two separable members 1, 2 are locked together and unlocked by the axial locking device. The first member 1 has a locking mechanism, which comprises an outer housing 3 which forms actuating means, mounted on the first member 1, being moveable axially relative to the first member 1 but substantially fixed relative to the first member 1 in the angular direction, ie rotationally. The motion of the outer housing 3 is limited by an annular flange 4 and an abutment ring 5. As shown more clearly in Figure 3, the first member 1 has an integral ring of teeth 6 with inclined ends (inclined at e.g. 45' to the axial direction), which are free to move axially between inwardly-projecting retaining teeth 7 integral with the outer housing 3, which teeth 7 also have inclined ends facing in the same direction (preferably inclined at the same angle). The teeth 6 are substantially fixed in a rotational sense with respect to the teeth 7. Within the outer housing 3, there is a cam slider 8 which is rotatable about the axis of the locking device; the cam slider 8 at one end has an integral ring of teeth 9 with inclined ends facing in the opposite direction to those of the teeth 6, 7, the ends being preferably inclined at the same angle as the ends of the teeth 6, 7. All the teeth 6, 7, 9 have the same pitch, but the teeth 6, 7 are half the width of the teeth 9. All the teeth 6, 7, 9 have flanks which are parallel to the axis of the locking device. The other end of the cam slider 8 has a wavy cam profile on its inner periphery, as illustrated in Figure 2. This cam profile co-acts with locking elements in the form of two or more balls 10 which are held captive in a return skirt integral with the outer housing 3 and which can engage in an annular recess 11 in the second member 2 in order to lock the second member 2 to the first member 1. The locking balls 10 are actuated by the cam profile, depending upon the rotary position of the cam slider 8. The cam slider 8 is biassed with constant force in one sense relative to the housing 3, by means of a spring 12 which acts effectively between the teeth 7 and the teeth 9, ie between respective parts fixed to the teeth 7 and 9. In operation, the abutment ring 5 on the housing 3 engages the second member 2 when the members 1, 2 are moved axially relative to one another in a first sense. The at-rest position is generally as shown in Figure 3a; the teeth effectively interlock, though there may be a small gap between the ends of the teeth 6, 7 and the ends of the teeth 9. The teeth 6, 9 act as first and second angular (or rotary or circumferential) thrust means. Considering movement of the first member 1 in the direction of the arrow shown in Figure 1, when the abutment ring 5 engages the end of the second member 2, the teeth 6 will, push back the teeth 9, as shown by the arrows in Figure 3b, hence pushing back the cam slider 8; the interengagement of the teeth 6, 9 biases the locking mechanism towards actuation; the teeth 7 remain stationary due to the abutment of the ring 5 on the end of the second member 2. This movement continues until the the flanks of the teeth 9 disengage the flanks of the teeth 7, ie until the tips of the teeth 9 clear the tips of the teeth 7 (which act as retaining means); at this point the teeth 6, 9 rotate the cam slider 8 as the cam slider 8 travels axially to the left under the action of the spring 12, until the flanks of the teeth 9 engage and are arrested by the flanks of the teeth 6, as shown in Figure 3c_, with an audible and tactile click or snap, this being a temporarily stable half-wave position. In this position, the locking balls 10 are not fully extended, but are sufficiently extended to lock the members 1, 2 together. The relative rotational movement between the teeth 6, 9 is powered by the spring 12 which is compressed on relative movement of the members 1, 2 in said one sense. When the first member 1 is moved to the left, the teeth 6 retract towards their original position, as shown in Figure 3d. Once they have cleared the flanks of the teeth 9, the inclined ends of the teeth 7, 9 act as angular thrust means, and the cam slider 8 finishes its rotation, clicking or snapping into the position in which the flanks of the teeth 9 again abut the flanks of the teeth 6, as shown in Figure 3a_. The device is now fully locked with the balls 10 fully extended. The teeth 7 act as retaining means which prevent actuation of the locking means, ie rotation of the cam slider 8, until a certain relative movement in said one sense has occured between the members 1, 2, whereupon the retaining effect is released with a snap or click. The retaining means 7, which retain the teeth 9 until the click or snap action occurs, need not be inclined teeth, although inclined teeth are the preferred form - for instance, they could be rounded pins. Likewise, the teeth 6 could have rounded ends or another profile (see Figures 4 to 5d). Alternatively, if the teeth 6, 7 have inclined ends, the teeth 9 could be differently shaped projections. The spring 12 could be placed around the cam slider 8, engaging an external annular projection on the cam slider 8, to make the locking mechanism more axially compact, though of increased diameter (a similar such arrangement as shown in the embodiment of Figures 8 to 9d). The device depends upon inertia or pull-back of the first member 1 for complete return of the housing 3 and of the cam slider 8 after actuation; if fully automatic return is desired, a light wavespring can be provided between the flange 4 and the teeth 6, biassing the housing 3 to the left. Figures 4 to 5d The axial locking device of Figures 4 to 5d is generally similar to that of Figures 1 to 3d, but the teeth 6, 7 and 9 are differently shaped, and the teeth 6 are partly offset radially from the teeth 7, protruding through cut-outs in the teeth 7, as shown in Figure 4. The teeth 6 have radiussed edges at their ends and the ends are surfaces at a large angle, e.g. 70', to the axial direction. The teeth 7 are of Vee or zig-zag shape, each tooth 7 being formed by two surfaces inclined to the axial direction at different angles, the leading surface (with respect to the direction of rotation of the slider) being inclined at a smaller angle to the axial direction than the trailing surface, the angles being e.g. 42' and 24 * . The teeth 9 are of Vee or zig-zag shape, alternate surfaces being at the same angle to the axial direction, for instance 42", but inclined in the opposite sense. The operation is generally similar to that of the device of Figures 1 to 3d. When the abutment ring 5 engages the end of the second member 2, the teeth 6 will push back the teeth 9, as shown by the arrows in Figure 5b, hence pushing back the cam slider 8, but the interaction of the curved edges of the teeth 6 with the inclined surface of the teeth 9 also causes the cam slider 8 to rotate, the teeth 9 sliding up the inclined flanks of the teeth 7; the interengagement of the teeth 6, 9 biasses the locking mechanism towards actuation, but the sliding flanks of the teeth 7, 9 prevent a step-wise rotation of the cam slider 8. This movement continues until the flanks of the teeth 9 disengage the flanks of the teeth 7, when the cam slider 8 will rotate rapidly and move slightly to the left under the action of the spring 12, until arrested by engagement with the other edges of the teeth 6, as shown in Figure 5σ_, with an audible and tactile click or snap. When the first member 1 is moved to the left, the teeth 6 retract towards their original position, as shown in Figure 5d, and the flanks of the teeth 9 ride down the edges of the teeth 6 and ride down the flanks of the teeth 7; as retraction of the teeth 6 continues, the tips of the teeth 9 will ride along the inclined ends of the teeth 6. Depending upon the precise profiling of the teeth 6, there can be a small click action as the teeth 6 fully retract into the position shown in Figure 5a_. The device is now fully locked with the balls 10 fully extended. The device of Figures 4 to 5d provides automatic return of the cam slider 8. Figures 6 and 7 The axial locking device of Figures 6 and 7 is very similar to that of Figure 1, but there are further means for actuating the locking mechanism to lock and unlock, and principally to unlock, the device without relative axial movement of the two separable members 1, 2. This modification permits external release or an emergency override, where no axial movement of the members 1, 2 is available but the members 1, 2 have to be separated. A housing extension 21 is formed on the housing 3, providing an end stop for an auxiliary actuating slider or sleeve 22 and also providing an abutment for a second spring 23. Slots 24 are formed in the housing 3, and inwardly-projecting auxiliary teeth 25 project in through the slots 24 and are aσcomodated between the teeth 6 and the teeth 7, as shown in Figure 7. On pushing the sleeve 22 to the right, the auxiliary teeth 25 push back the teeth 9 in the same way as the teeth 6 push back the teeth 9 in the illustration of Figure 3_c, the teeth 6 remaining stationary because there is no relative movement between the members 1, 2. In this way the cam slider 8 can be precessed externally of the device without disturbance of the main locking elements. Figures 8 to 9d The axial locking device of Figures 8 to 9d is similair in function to that of Figures 1 to 3d. In this case, the first member 1 forms the outer housing, and the actuating means is an abutment member 3 which is axially moveable with respect to the first member 1 but is substantially fixed rotationally with respect to the first member 1, having integral, projecting teeth 6 which pass through axial slots cut in the inner wall of the first member 1. The teeth 7 are integral with the inner wall of the first member 1. The teeth 9 are integral with the cam slider 8. The cam slider 8 has an outwardly projecting flange 31 which forms an abutment for the spring 12. In general, the locking mechanism leaves more available room for the spring 12 than that of Figure 1, but is wider and shorter. The operation of the embodiment is as shown in Figures 1 to 3d, but in this case the second member 2 is considered to be moving, the first member 1 being fixed. The housing forming the first member 1 is a rigid assembly, and can terminate in a flange (as shown) or in a male or female configuration. The embodiment can be modified to have an auxiliary slider for external actuation, generally as shown in Figures 6 and 7. In the embodiments of Figures 1 and 8, the locking mechanisms can be arranged so that the balls 10 expand outwards to lock, instead of expanding inwards, the locking mechanism being in a male member instead of in a female member (see for instance Figure 16 or 22). The embodiments of Figures 1 and 8 provide a simple construction with relatively few parts. Figures 10 to lib In the embodiment of Figures 10 to lib, the first member 1 provides a housing having integral engaging elements in the form of wave-form detents or teeth 41 (see Figures lla_ and lib). The teeth 41 interengage with complementary wave-form elements in the form of detents or teeth 42 integral with the end of the cam slider 8. The teeth 41, 42 give a stabilising or detaining effect at predetermined intervals around the periphery where the teeth 41, 42 fully engage. More specifically, relative rotational movement can occur between the first member 1 (which forms the first part of retaining means) and the cam slider 8 (which forms the second part of retaining means) only if relative axial movement occurs between the first member 1 and the cam slider 8. Rotational force applied between the teeth 41, 42 causes the relative axial movement due to camming. The biasing or spring means are different. The biasing means also act as angular thrust means and comprise a ring of sprung elements 43 (which may be referred to as tines, tabs or teeth) integral with the other end of the cam slider 8. The elements 43 are skew or canted, being inclined to the axis of the device and to the rotational direction. The distal or free ends of the elements 43 are engaged by reaction means in the form of a series of ratchet-like or sawtooth-like teeth 44 integral with a ring 3 which acts as an abutment ring and as the actuating means; each tooth 44 has a surface parallel to the axial direction and a surface at e.g. 8 * to 16" to the axial direction. The ring 3 is retained in the housing forming the first member 1 by a small lip 45 and is also keyed to the first member 1, eg by external tabs 46 moving in short axial slots in the first member 1 (as shown) or by outer or inner splines.. The arrangement is such that when relative movement occurs between the members 1, 2 and the abutment ring 3 moves to the left as shown by the single-headed arrow in Figure lib, the sprung elements 43 lock into the reaction teeth 44, are compressed, and are bent or deflected in a peripheral direction, imparting angular thrust to the cam slider 8 in the direction of the double-headed arrow shown in Figure lib, ie biasing the locking mechanism towards actuation. However, the cam slider 8 is temporarily restrained by the teeth 41, 42 and does not rotate until considerable force has been exerted upon the sprung elements 43, whereupon (at the point illustrated in Figure lib) it suddenly jumps one tooth pitch relative to the first element 1; as the cam slider 8 rotates, the rotary biasing force due to the sprung elements 43 decreases so that there is little tendency for more than one tooth pitch to be jumped. A dull click occurs as the cam slider teeth 42 snap past the apices of the teeth 41. The allowable rotary movement must be in excess of one half tooth pitch but not in excess of one tooth pitch. The geometry of the sprung elements 43 and of the reaction teeth 44 is such that when the abutment ring 3 has been forced fully to the left, the cam slider 8 has progressed one tooth pitch of the reaction teeth 44. As the abutment ring 3 returns on moving the members 1, 2 apart in the other sense, the sprung elements 43 straighten and their spring action pushes the abutment ring 3 back; as the sprung elements 43 straighten to their original canted positions, they jump one tooth 44 and engage the troughs of the new reaction teeth 44. As shown in Figure 10a., the ends of the sprung elements 43 engage about half way between the crests of the teeth 44, in the rest position. The teeth 41, 42 will be phased to suit. The locking balls 10 are then fully extended. The stroke of the cam slide 8 and the interaction between the sprung element 43 and the teeth 44 is such that the sprung elements 43 store only enough radial movement component to rotate the cam slider 8 just far enough for the teeth 42 to engage in the next tooth 41 when the relative axial movement is reversed. AB indicated above, the cam slider 8 has only to rotate slightly more than one half the pitch of the teeth 41, 42, and must not rotate more than one pitch. This allows a significant margin. As the apices of the teeth 41, 42 clear each other, the bend of the sprung elements 43 must be enough for them to spring at that point, trying to straighten, and in so doing impart enough rotation to the cam slider 8 for the apices of the teeth 41, 42 to pass each other so that the locking device indexes into the next tooth engagement 41, 42 once the relative axial movement is reversed. At this point, the sprung elements 43 should still be engaged with the teeth 44 so that the friction of the sprung elements 43 against the teeth 44 provides enough force to retain the cam slider 8 within the domain of the next tooth 41 as the reverse relative axial movement occurs. Thus the bending of the sprung elements 43 is not just enough to merely push the cam slider 8 to its new rotary position, but must also have a straightening component which jams the distal ends of the sprung elements 43 against the flanks of the teeth 44 until the apices of the teeth -41, 42 have passed. The sprung elements 43 should be sufficiently long to touch some part of the teeth 44 at all times, even when the locking device is fully relaxed in its inactive state. Naturally, the speed of operation must be reasonable; a hammer blow operation could cause the cam slider 9 to overshoot and jump an extra tooth 41, 42. The locking device will remain locked until relative movement in the first sense again occurs between the members 1, 2, when the cycle will repeat and the alternate cam surface will be offered to the locking balls 10, allowing them to retract and allowing the members 1, 2 to be fully parted. The sprung elements 43 are designed so that they are never stretched beyond their elastic limit. This can conveniently be arranged by making the abutment ring 3 reach the limit of its movement when it is flush with the right-hand end of the housing formed by the first member 1. The elements 43 and cam slider 8 can be made of a plastics material, e.g. injection-moulded nylon with carbon fibre reinforcement. For special cases, such as very hot or cold environments, the sprung elements 43 may be made of a material different to that of the cam slider 8, for instance alloy steel injection moulded into a plastics material slider 8 or assembled later .and retained for instance with crimping. If for instance the teeth 44 were sufficiently inclined, the sprung elements 43 could be parallel with the axis of the device, the elements 43 compressing and bending along the inclined surfaces of the teeth 44. The reaction means, which are preferably formed by teeth 44, need not have the form described above and could for instance be simply a ring of tiny radial ridges, or even merely a rough surface or a surface having a suitable coefficient of friction with the sprung elements 43. Figures 12 to 13d Figure 12 shows an axial locking device in which the actuating means 3 is an inwardly-projecting lip which is integral with the cam slider 8 so that the cam slider 8 is directly moved to the left relative to the member 1 when the members 1, 2 are brought together. This lifts the Vee teeth 41, 42 apart (see Figure 13b), which teeth 41, 42 act primarily as detent means to detain the cam slider 8 rotationally when it has been moved to a new rotational position; the surfaces of the teeth 41,42 are inclined at 30 * to the axial direction. The depth of. engagement of the teeth 41, 42, and their profiling, can be such that the rotation- of the cam slider 8 causes the flanks of the teeth 41, 42 to be pressed together so that cam slider 8 suddenly jumps when the teeth 41, 42 disengage (Figure 13b) with a click action. As in the embodiment of Figures 10 to lib, the geometry of the sprung elements 43 and of the reaction teeth 44 is such that when the abutment lip 3 has been forced fully to the left (Figure 13c_), the cam slider 8 has progressed one tooth pitch of the reaction teeth 44. As the abutment lip 3 returns on return movement of the members 1, 2, the sprung elements 43 straighten to their original positions without applying any effective rotational force to the cam slider 8; rotation of the cam slider 8 will normally be prevented by the frictional means, in this case by engagement of the abutment lip 3 on the member 2. The cam slider 8 has progressed one tooth pitch of the reaction teeth 44, the locking balls 10 are fully extended, and the device is fully locked. Figure 13d shows the cam slider 8 moving back immediately prior to the elements 43 clicking into their new tooth troughs. The cycle is repeated when the members 1, 2 are again moved towards each other, unlocking the device. Figure 13a. shows the arrangement in the rest position. Purely by way of example, Figure 12 illustrates members 1, 2 in the form of conduits for fluid, sealed by O-ring seals 51. The general arrangement is suitable for electrical connectors or liquid or gas connectors. Figure 14 The teeth 41, 42 may have other shapes, for instance sinusoidal or large-radius semi-circular - a smooth, wavy form gives a more gentle effect, though a less definite engagement point. Figure 14 illustrates a modification of the device of Figure 12, where the teeth 41, 42 are wavy, and also have a significantly smaller crest-trough distance. Figure 15 Figure 15 illustrates a device similar to that of Figure 12 or Figure 14, but with the abutment means 3 in the form of a cap integral with the cam slider 8. The general arrangement is suitable for a mechanical fastening device. Figures 16 and 17 Figures 16 and 17 correspond closely to Figure 15, but show the locking mechanism in the male member 1. The actuating or engaging means is a projection 3 protruding through the end of the male member 1 and which moves axially relative to the male member 1 when it engages the female member 2. Figure 17 shows the closer tooth pitch that is required because the pitch circle is of smaller diameter. Figures 18 and 19 Long fatigue life designs are possible for the spring elements 43, if the bend is spread over the maximum portion of their length, reducing local stress. Two such designs are shown in Figures 18 and 19 and are applicable to any of the appropriate embodiments. The elements 43 are of circular section, and bend slightly in the circumferential sense to follow the curve of the confining member 1 or 3. There are ruggedness and resilience benefits in reducing the number of spring elements 43, even down to two or three, so that the number need not be as shown in any of the embodiments. For example, these can be half the number of spring elements 43 in Figure 17, the teeth 44 remaining the same. Figures 20 to 21c Figure 20 shows an axial locking device which is similar in principle to that of Figure 13 of US 4 709 454, and which need not be described in detail. The cam slider 8 is a sleeve. The actuating or engaging means is a disc 3 which is integral with one end of the cam slider 8. ' The disc 3 has an annular part projecting beyond the cam slider 8 in the form of a flange, and on each axial face of the flange there is an annular set of teeth 61, 62 for engaging respective facing annular sets of teeth 63, 64 integral with, or fixed to, the first member 1. The interengaging sets of teeth 61, 63 and 62, 64 serve to rotate the cam slider 8. As the cam slider 8 reciprocates back and forth, it precesses in rotary motion, as is illustrated in Figures 21a_ to 21c_. The biasing of the cam slider 8 is in the form of a snap-action dished spring 65 which is co-axial with the locking device. Its characteristic is such that it normally maintains the cam slider 8 in its right-hand position, but when it is pushed to the left, the spring 65 flattens and clicks as it converts from convex one side to convex the other side, whilst still retaining a bias towards the right. This provides an audible click and alsσ provides tactile feed-back to the second member 2. Fi gure 22 Figure 22 illustrates how the arrangement of Figure 20 can be applied to a male first member 1; the Figure 22 device operates on the same principle as that of Figure 15 of US 4 709 454. The locking balls 10 are given an extended reach by the insertion of short plunger elements 71 between pairs of locking balls 10. Figure 22 also illustrates that an auxiliary spring 72 can be associated with the. spring 65, if desired, particularly in order to give a very long movement of the cam slider 8. The spring 72 is contained in a counterbore in the cam slider 8. Figure 23 Figure 23 shows an axial locking device which in general principle is similar to that of Figure 15 of US 4 709 454. The embodiment is a light weight embodiment whose first member 1 can have .an outer diameter of as little as 4 mm, providing a compact linear latch. The locking mechanism is shown associated the male member 1, for locking it to a female member 2 in the form of a cup. The male member 1 has swaged ends. The actuating means is a rod 3 which is guided for axial sliding movement with respect to the member 1 by two bushes or stators 81, 82 fixed in the member 1 by swaged locking annuli. A collar 83 is fixed to the far end of the rod 3, and provides an abutment for the return spring 12. In its central portion, the rod 3 carries and is fixed to a rotor 84. The front end of the rod 3 has a part which acts as the locking means or angularly moveable locking member or cam slider 8, rotation of the rod 3 offering alternate high and low points of the cam to locking balls 10 which can engage a detent 11 formed by a swaged annulus in the member 2. The rotor 84 has oppositely-facing rings of inclined-teeth 9, 85 co-acting with repective rings of teeth 6, 7 on the bushes 81, 82. The bushes 81, 82 of a special construction so that their teeth 6, 7 are spring biased in opposing axial directions. Serrations are cut in the bushes 81, 82. The serrations can be of any suitable configuration, such as the herringbone configuration shown or a zig-zag configuration, as long as the respective bush 81, 82 has a resilient axial compliance between the respective ring of teeth 6, 7 and the locking annulus where the bush 81, 82 is fixed. The bushes 81, 82 can be formed of a suitable plastics material. With the arrangement described above, and a suitable spacing between the bushes 81, 82, the axial locking device can operate in principle exactly as that of Figure 15 of US 4 709 454. On moving the female member 2 in the direction of the arrow shown in Figure 23, the rotor 84 moves until its teeth 9 engage the teeth 6, when the teeth 6, 9 act as second and first angular thrust means (using the terminology above). The teeth 6 are then pushed against the inherent spring biasing of the bush 81, but relative rotation is prevented by the interengagement of the flanks of the teeth 7, 85, which act as retaining means, the locking mechanism being biased towards actuation. When the tips of the teeth 85 clear the tips of the teeth 7, the rotor 84 rotates until its teeth 9 click into full engagement with the teeth 6. When the motion of the second member 2 is reversed, the main return spring 12 pushes the rotor 84 back, and must be stronger than the springing provided by the bush 81. A similar snap or click .action occurs as the tips of the teeth 9 clear the tips of the teeth 6, in this case, the teeth 7, 85 acting as first and second angular thrust means and the teeth 6, 9 acting as retaining means. Figures 24 to 28 Figures 24 to 28 illustrate alternatives to the use of the balls 10 as locking elements. In Figures 24 and 25, the axial direction is left to right across the page, and the top part of the locking element shown is engaged by the cam profile of the cam slider 8. Figure 24 illustrates a flat tee tab or slipper 91 and Figure 25 illustrates a rounded tee tab or slipper 92. Figures 26a and 26b illustrate an arrangement that can be incorporated for instance in Figure 10. Figure 26a_ shows the configuration with the members 1, 2 locked, whilst Figure 26b shows a configuration with the members 1, 2 unlocked. The locking elements are lugs or tags 93 which are integral with a thin-walled deformable tab ring 94, which can be made of plastics or resilient metal. The tabs 93 are shown projecting through holes in the housing of the female first member 1. However, as shown in Figures 27 and 28, the tab ring 94 can alternatively form the housing of a female first member 1, either being suitably thin walled with a continuous wall (Figure 27), or being thicker walled with a split skirt (Figure 28). The cam slider 8 can be provided with an axial groove containing a ball or a roller 95, as shown in Figure 26a, or can merely have a raised cam lobe. This arrangement is useful when it is not suitable to have locking balls 10 projecting through the wall of the first member 1; also, this arrangement can reduce costs and simplify design. General The members 1, 2 can be solid, or one can be tubular and the other solid or both can be tubular. If they are both tubular, there can be a gap between them, or one can have an extension so that it slides into the other: suitable seals for fluids, or plugs and sockets for electrical connections, or integrating devices for fibre optics connections, can be provided. Correspondingly, parts such as the abutment member 3 in Figure 8 can have an aperture through the centre (see Figure 12). However, the locking device can be used as a simple releasable fixing. For instance, with an electrical plug and socket connection, electrical pins can be in the centre zone of the locking device, with the locking arrangement around the outside of the electrical pins; alternatively, there can be an additional pin formed as the locking device. There is a small' return movement on locking. Such a return movement may not be desirable with electrical connectors or fibre optic connectors. One way of avoiding this is to design the locking device so that the male and female elements remain fully pushed together with the connection is made, by friction. If they are pulled, they can only be parted by the pre-set return distance, and then they will stop. In an alternative arrangement, which is preferred for fibre optics connectors, the locking device is in the form of a sleeve surrounding the connector and axially slidable with respect to the connector. The connector is spring-loaded against the sleeve so that the connector goes fully home when the sleeve is pushed, and remains fully home even when the sleeve makes the return movement. In a different application, two of the axial locking devices of the invention (e.g. of Figure 23) can be used to latch a fast clamp/unclamp device for computer cables, the clamp/unclamp device being in the form or a bridge with an axial locking device at the foot of each leg. The yoke can be sufficiently resilient to allow the computer cable connector to remain fully home on the return movement. Figure 29 More generally, the locking device may for instance be used to fasten items to a fixture such as a bulkhead, in which case a hole in the fixture can itself act as the female member, or a bush or grommet can be provided in the fixture to act as the male member or the female member; proud mounting or flush mounting can be provided; the member which is releasable from the fixture can be provided with any suitable type of fixing, such as having male or female threads or arranged for a swaging fitting or for screwing into. As an alternative to the bush or grommet, the respective member can for instance be welded to a metal panel, without forming an opening. Figure 29 shows a specific arrangement for fastening a panel 101 to a fixture 102. The locking device is that of Figure 15, but any suitable locking device can be used. The female member 1 is secured to the fixture 102, for instance by means of a snap ring 103, so that its front (right-hand) face is nearly flush with the fixture 102. The male member 2 is necked, passes through the panel 101 as a loose fit, and carries a head 104 which entraps a compression spring 105 between itself and the panel 101. When the panel 101 is brought up to the fixture 102, the engagement is as shown in Figure 29, and is insufficient to latch (lock). When the end of the male member 2 is depressed against the action of the spring 105, the locking device latches and the panel 101 is attached and pre-loaded by the force of the spring 105. This arrangement is suitable for large panels 101 with a number of fasteners which could not be all engaged simultaneously by movement of the panel 101. As shown, the panel 101 can be dished at the locations of the locking devices so that the exposed ends of the locking devices are substantially flush with the outer surface of the panel 101 when all the locking devices are latched up. Figures 1, 8, 10, 12, 15, 16, 20, 22 and 29 of the drawings indicate how parts which are otherwise integral are made up of separate components in order to enable the devices to be assembled; this is on the basis that the body members are formed of injection-moulded plastics components which are secured together by ultrasonic welding or by adhesives. The split lines (ie where the components mate) can be wherever appropriate. However, other materials and other techniques can be used. The present invention has been described above purely by way of example, and modifications can be made within the scope of the invention.

Claims: CLAIMS 1. An axial locking device for locking together and unlocking two separable members by relative movement of the two members in one axial sense, the device comprising a locking mechanism which is associated with a first of the members, the locking mechanism comprising means for causing a click action to occur as the locking mechanism is partly or fully actuated. 2. The device of Claim 1, and comprising means which, on said relative movement of the members, bias the locking mechanism towards actuation, and retaining means which preveent actuation of the locking mechanism until said relative movement has occured, the retaining effect then being released with a click. 3. The device of Claim 1 or 2, wherein the locking mechanism comprises; a locking element for engaging the second member to lock the members together; actuating means moveable with respect to the first member and engageable by the second member when said relative movement occurs, to initiate actuation of the locking mechanism; locking means which are relatively angularly moveable to actuate the locking element; first angular thrust means; second angular thrust means which co-act with the first angular thrust means and are substantially fixed in an angular sense with respect to the locking means; retaining means which are substantially fixed in an angular sense with respect to the first angular thrust means; the arrangement being such that on said relative movement of the members, the first and second angular thrust means will be in engagement with one another, and the first and/or second thrust means will move axially with respect to the retaining means whilst the retaining means initially prevents relative angular movement of the second angular thrust means and then allows relative angular movement of the first and second angular thrust means, with a click action. 4. The device of Claim 2, wherein the retaining means comprise a first part which is moveable both axially and angularly with respect to a second part, the parts having interengaging elements such that relative angular movement can occur between the parts only if relative axial movement also occurs between the parts, at least one of the interengaging elements having a cam profile such that a force applied between the parts in an angular direction causes relative axial movement between the parts> biasing means whose biasing force is increased by said relative axial movement of the members, biasing the parts toward relative angular movement therebetween and arranged such that as said relative axial movement progresses, the biasing force increases to such a value that the relative axial and rotary movements between the parts occur, whereon the biasing force is decreased. 5. The device of Claim 2, wherein the retaining means comprise a first part which is moveable both axially and angularly with respect to a second part, the parts having interengaging elements such that relative angular movement can occur between the parts only if relative axial movement also occurs between the parts, the device comprising actuating means movable with respect to the first member and engageable by the second member when said relative movement occurs, to initiate actuation of the locking mechanism, the actuating means inducing relative axial movement between the parts, and comprising biasing means biasing the parts towards relative angular movement therebetween, the arrangement being such that after a predetermined relative axial movement between the parts, the parts disengage with a click. 6. The device of Claim 1, wherein the click action is provided by a click action spring which is actuated on said relative axial movement of the two separable members. 7. An axial locking device for locking and unlocking two separable members by relative movement of the two members in one axial sense, the device having a locking mechanism associated with a first of the members, the locking mechanism comprising: actuating means moveable with respect to the first member and engageable by the second member when the second member is moved in said one sense relative to the first member, to initiate actuation of the locking mechanism; locking means which are angularly moveable with respect to the actuating means to lock and unlock the members; angular thrust means which comprise at least one sprung projecting element; and reaction means engagable with the sprung element; the arrangement being such that when the relative movement occurs between the members, the sprung element is deflected and the locking means are caused to move angularly. 8. The device of both Claim 4 or 5 and Claim 7, and comprising detent means which detain the locking means when they have been moved angularly, the detent means comprising said first and second parts, the force in an angular direction being applied by the sprung element. 9. The device of Claim 7 or 8, wherein the reaction means comprise a toothed ring in which the distal end of the sprung element engages. 10. An axial locking device for locking together and unlocking two separable members by relative movement of the two members in one axial sense, the device having a locking mechanism associated with a first of the members, the locking mechanism comprising: locking elements for engaging the second member to lock the members together; and actuating means moveable with respect to the first member and engageable by the second member when the second member is moved in said one sense relative to the first member, to inititate actuation of the locking means, the actuating means being integral with the locking means, and the locking means comprising a sleeve co-axial with the device and having the actuating means at one end, the integral components so formed having an annular part projecting beyond the sleeve, there being on each axial face of the annular part a ring of teeth for engaging respective facing rings of teeth fixed with respect to said one member, for rotating the actuating and locking means about the axis of the device, to thereby lock and unlock the members.

Inventors: BARNES AUSTEN BERNARD, BARNES, AUSTEN, BERNARD
Applicants: BARNES AUSTEN BERNARD, BARNES, AUSTEN, BERNARD
Application year: 1990
Main classification: F16L37
IPC codes: F16B21, F16L37, H01R13