GB2392202A

GB2392202A - Assembly of movable and lockable parts

Info

Publication number: GB2392202A
Application number: GB0315511A
Authority: GB
Inventors: Julian Paul Makinson
Original assignee: Avon Vibration Management Systems Ltd
Current assignee: Avon Vibration Management Systems Ltd
Priority date: 2002-08-21
Filing date: 2003-07-02
Publication date: 2004-02-25
Anticipated expiration: 2023-07-02
Also published as: DE10337527B4; GB0219497D0; GB2392202B; DE10337527A1; GB0315511D0

Abstract

An assembly of automotive parts comprises first and second parts 1, 10 which are moveable relative to each other between a plurality of predetermined positions in which the parts are lockable together to resist further relative movement. The Assembly can be used in many different engines by simply adjusting the position in which the parts are locked. The first part 1 has at least first and second apertures 6a, 6b spaced apart from each other and the second part 10 has a plurality of teeth 12, the teeth being deformable and extendible into said apertures. Each aperture is sized to fit a predetermined maximum number of teeth and only one of said first and second apertures is aligned with its predetermined maximum number of teeth at any one time. In this way the parts can be moved between a plurality of locking positions in which they are lockable by extension of the predetermined maximum number of teeth into either the first or second aperture.

Description

ASSEMBLY

The present invention relates to an assembly in which a first part and a second part which are movable relative 5 to each other between a plurality of predetermined positions in which they can be locked together to resist further relative movement. It can be applied to parts which are moved linearly relative to each other and also to parts which are rotated relative to each other so as 10 to change their relative orientation.

The present invention finds its primary, but not exclusive, use in the automotive industry. For example, it could be used where the relative positioning or orientation of a pair of standard automotive parts has to 15 be fixed precisely, but the required relative positioning or orientation varies according to the particular engine in which the parts are used.

In previous assemblies it has been possible to move a first and second part relative to each other until a 20 desired position is reached, and then to permanently lock the parts together in this position, e.g. by soldering or use of an adhesive. However, it has not been possible to temporarily lock the parts together in a first position, unlock the parts from this first position and then more 25 them relative to each other into one or more other positions in which they can be temporarily locked together. Accordingly, a first aspect of the present invention provides an assembly of automotive parts comprising: 30 a first part and a second part which are movable relative to each other and which can be locked together to resist further relative movement when in certain predetermined positions;

the first part having at least a first and a second! aperture, said apertures being spaced apart from each other; the second part having a plurality of teeth and gaps 5 between adjacent ones of said teeth, the teeth being deformable and expendable into said apertures when aligned therewith; each of said apertures being sized to fit a predetermined maximum number of teeth, which 3 10 predetermined maximum number of teeth may or may not be the same for each aperture;, the spacing of the apertures being selected such L that the first and second parts can be moved relative to each other into: 15 a first position in which the first aperture is aligned with a number of teeth equal to its predetermined maximum number of teeth such that said teeth extend into t said first aperture so that one of said teeth abuts against a first side wall of said aperture and one of 20 said teeth abuts against a second side wall of said aperture thereby resisting relative movement of said first and second parts, and wherein in said first position said second aperture is not aligned with its predetermined maximum number of teeth; and 25 a second position in which the second aperture is aligned with a number of teeth equal to its predetermined maximum number of teeth such that said teeth extend into said second aperture so that one of said teeth abuts against a first sidewall of said second aperture and one 30 of said teeth abuts against a second sidewall of said second aperture thereby resisting relative movement of said first and second parts, and wherein in said second position said first aperture is not aligned with its predetermined maximum number of teeth.

Normally, each aperture will be sized to fit a predetermined maximum number of teeth greater than one.

In this case, when the predetermined maximum number of teeth extend into an aperture, the tooth abutting against 5 the first sidewall of said aperture will be a different tooth to the tooth abutting against the second sidewall of said aperture. However, it would theoretically be possible for an aperture to be sized to fit only one tooth, in which case the predetermined maximum number of 10 teeth for said aperture would be one and in the locking position for said aperture this one tooth would abut against both sidewalls of the aperture, thus locking the two parts together to resist further relative movement.

The first or second aperture or both may be sized to fit 15 only one tooth; as may any other additional apertures in the first part.

In the context of this application, locking of the two parts means that teeth (or a tooth) of the second part engage with an aperture of the first part to resist 20 further relative movement of the two parts. The two parts can be unlocked by moving a tooth abutting against a sidewall of the aperture out of the aperture so that it no longer extends into the aperture. Positions in which the parts can be locked together (e.g. the first position 25 and the second position mentioned above) are referred to as lockable or locking positions.

Thus, the first and second part can be moved into the first position and locked there by extension of the predetermined maximum number of teeth into the first 30 aperture. As a tooth then abuts against each sidewall of the first aperture, further relative movement in the sideways direction is resisted (or in the case that the parts are rotatable relative to each other further rotational movement of the parts is resisted).

t locking of the parts in the first position is achieved by extension of teeth into the first aperture.

It is not possible to lock the parts in the first position by extension of teeth into the second aperture, 5 because in the first position the second aperture is not aligned with its predetermined maximum number of teeth.

Even if some teeth extend into the second aperture when the parts are in their first position, teeth will not abut against both side walls of the second aperture and 10 so some further relative movement will be possible unless the parts are locked by extension of teeth into the first aperture. From the first position, the parts can be unlocked (by pushing at least one of the teeth abutting against a 15 sidewall of the first aperture back out of the aperture) and moved on to the second position, in which they are locked together by extension of teeth into the second aperture, so that a tooth abuts against each sidewall of the second aperture, thus resisting further relative 20 movement of the two parts.

Thus, by appropriate selection of the spacing of the first and second positions (which is determined by the spacing of the first and second apertures), it is possible to design an assembly in which the first and 25 second parts can be moved between and locked into two desired configurations.

The assembly can be configured so that relative movement of the parts is by linear movement of the parts or by rotation of the parts, e.g. about a common axis. In 30 the latter case the first and second positions correspond to different orientations of the parts relative to each other. Normally the apertures will be rectangular in shape, in which case the sidewalls may be formed by the short

sides of the rectangle. However, the apertures could have a square crosssection in which case opposing sides would form the sidewalls, or circular in which case the sidewalls which the teeth abut against would be opposing 5 points on the circular circumference of the aperture.

It is important to note that, in the first position, the first aperture is aligned with its predetermined maximum number of teeth, but the second aperture is not aligned with its predetermined maximum number of teeth 10 and vice versa for the second position. This means that the two positions are not coincident. The full importance of this will become apparent later.

It is also important to note that each aperture is sized to fit a predetermined maximum number of teeth. It 15 is this which enables locking of the parts by extension = of the maximum number of teeth into one of the apertures.

The predetermined maximum number of teeth may be one, but -

preferably is an (integer) number greater than one.

For example, in one embodiment each tooth has a 20 width of 4mm and there are gaps of 2mm between adjacent teeth, and the first and second apertures both have a width of lOmm; thus the first and second apertures are -

each sized to fit a maximum of two teeth (each aperture has a width of lOmm and two teeth and the gap between the 25 teeth have a total width of 2*4mm +2mm = lOmm).

In alternative embodiments the first and second apertures can be sized to fit different predetermined maximum numbers of teeth, e.g. the first aperture could i be sized to fit a maximum of four teeth and the second -

30 aperture a maximum of five teeth. In other embodiments in which the two parts are rotatable relative to each other the tooth, gap and aperture widths can be expressed in terms of the angle they subtend to the axis of rotation.

In many applications it will be desirable to have more than two positions in which the parts can be fixed.

Accordingly, there are preferably further positions in which the parts can be locked by extension of the 5 predetermined number of teeth into the first or second aperture. This may be achieved by providing one or more arrays of teeth on the second part, with the teeth which engage with the first or second aperture corresponding to different parts of the array(s) in different positions.

10 Preferably, after the parts have been moved from the first position to the second position, continued movement of the parts in the same direction can bring them to a third position, in which the first aperture is again aligned with its predetermined maximum number of teeth 15 but the second aperture is not. Preferably further continued movement of the parts after the third position can bring them to a fourth position in which the second aperture is again aligned with its predetermined maximum number of teeth but the first aperture is not. In the 20 third position the predetermined maximum number of teeth extend into the first aperture to lock the parts together and the fourth position the predetermined maximum number of teeth extend into the second aperture to lock the parts together.

25 There may be still further positions in which the parts can be locked by extension of teeth into the first or second apertures. If the parts are moved relative to each other by rotation thereof then continued movement of the parts in the same relative direction (e.g. clockwise) 30 will eventually (after 360 of rotation) result in the parts returning to the first position.

In one embodiment, the first and second parts are rotatable and within the 360 of rotation there are sixty different positions in which the first aperture is

aligned with its predetermined maximum number of teeth and sixty different positions in which the second aperture is aligned with its predetermined maximum number of teeth.

5 As mentioned above, when the first aperture is aligned with its predetermined maximum number of teeth, the second aperture is not aligned with its maximum number of teeth, and when the second aperture is aligned with its maximum number of teeth the first aperture is 10 not aligned with its predetermined maximum number of teeth. Thus the positions (e.g. the first and third positions) in which the parts are locked by extension of teeth into the first aperture, are not coincident with the positions in which the parts are locked by extension 15 of teeth into the second aperture (e.g. the second and fourth positions). This enables provision of a greater number of lockable positions, so that the orientation or relative positioning of the first and second parts can be determined more precisely.

20 Put another way, the provision of a second aperture which is aligned with its predetermined maximum number of teeth at a position or positions in which the first aperture is not so aligned, allows for more closely spaced locking positions without reducing the widths of 25 the teeth or gaps between the teeth.

The teeth need not be in a continuous array in order to achieve a structure in which the parts lock in the first and second or other positions as described above.

However, the teeth are preferably in a continuous array 30 because this maximises the number of positions in which the parts can be locked.

If there is a continuous array of teeth and the widths of the teeth and gaps between them are uniform, then positions in which the first aperture is aligned

with its predetermined maximum number of teeth (thus enabling locking with the first aperture) will occur at regular intervals. In general such positions (e.g. the first and third positions mentioned above) will be 5 separated by the sum of the width of a single tooth and the width of the gap between two adjacent teeth, as this is the minimum relative movement required to move one tooth wholly out of the aperture and another tooth wholly into the aperture to replace it 10 For example, if the parts are rotatable relative to each other and the first aperture has an angular width of 22 and the second part has a continuous array of teeth each with angular width 4 and gaps of angular width 2 between adjacent teeth, then the first aperture is sized 15 to fit four teeth (4x4 for the teeth + 3x2 for the gaps therebetween = 22 ) and successive rotations of 6 (the combined angular width of a gap and a tooth) will move the parts between positions in which the first aperture is aligned with its predetermined maximum number of 20 teeth.

Thus, in the above example, the provision of a first aperture allows provides only 60 lockable positions in the full 360 of rotation. However, as there is a second aperture and the positions in which the second aperture 25 is aligned with its predetermined maximum number of teeth are not coincident with positions in which the first aperture is aligned with its predetermined maximum number of teeth, the second aperture provides for 60 further lockable positions. These lockable positions are also 30 spaced by 6 from each other.

Preferably the positions in which the second aperture is aligned with its predetermined maximum number of teeth are equidistant from successive positions in which the first aperture is aligned with its

predetermined maximum number of teeth. In the above example this gives the result that the parts can be locked every 3 .

The separation of the first and second positions 5 (and, where present, the separation of the second and third and third and fourth positions eta) is determined by the spacing of the first and second apertures and the widths of the teeth and gaps between the teeth.

The present invention has been described so far with 10 reference to first and second apertures. Preferably, however, the first part has one or more further apertures for providing one or more intermediate positions, between said first and second positions, in which the parts can be locked together. This provides even more positions in 15 which the parts can be locked.

In the above example, where there are 3 of rotation between the first and second positions, addition of further apertures with appropriate spacing from each other could enable the parts to be locked every 1 of 20 rotation.

Each aperture for providing an intermediate position in which the parts can be locked, is spaced from the other apertures such that when the parts are in the intermediate position corresponding to that aperture, the 25 aperture is aligned with its predetermined maximum number of teeth, but the first aperture, second aperture and any apertures for providing other intermediate positions are not aligned with their predetermined maximum number of teeth. Thus the parts can be locked in a given 30 intermediate position by extension of teeth into an aperture corresponding to that intermediate position.

Preferably the spacing of the apertures (first, second and intermediate) is selected such that the lockable positions of the first and second parts are

regularly spaced. For example the spacing of the apertures could be such that the parts can be locked every l of rotation.

The second part may also have one or more further 5 apertures for reinforcing the locking in existing lockable positions. In terms of their alignment with teeth in the second part, each of these 'reinforcing' apertures corresponds either to the first aperture, the second aperture or one of the intermediate apertures.

10 For example the first part may have a 'reinforcing' aperture which is aligned with its predetermined maximum number of teeth when the first aperture is aligned with its predetermined maximum number of teeth and which is not aligned with its predetermined maximum number of 15 teeth when the first aperture is not aligned with its predetermined maximum number of teeth. Thus, when the parts are in the first position they are locked together by extension of teeth into the first aperture and/or said corresponding reinforcing aperture. There may be other 20 'reinforcing' apertures corresponding to the second aperture and to any intermediate apertures. Thus each aperture may have one or more corresponding 'reinforcing' apertures. Such reinforcing apertures help to reinforce the 25 locking of the parts in the lockable positions as they enable the parts to be locked by extension of the maximum number of teeth into more than one aperture at once. They will be useful in applications were large forces or torques are applied to the parts or in situations were 30 the teeth are liable to fail.

The above discussion has focused on the relationship between the apertures, teeth and gaps between the teeth, which achieves locking of the first and second parts in

desired positions. The physical characteristics of the parts will now be considered.

Preferably the assembly is an assembly of automotive parts. 5 The teeth may be biased against the first part such that they spring into an aperture when aligned with it.

This facilitates automatic locking of the parts when a locking position is reached.

The teeth and apertures may be arranged in circular 10 formations. For example they may be arranged in concentric circles with the teeth on the outer circle and the apertures on the inner circle or visa versa.

Preferably the first part has a plurality of legs arranged to define a circle and gaps between adjacent 15 legs form the apertures in the first part. The legs may project from a surface of the first part. This allows for easy construction of the apertures.

Preferably the teeth project from a ring shaped member of the second part. This facilitates rotation of 20 the second part relative to the first part.

Preferably when in their un-deformed state, the teeth define a circle of slightly larger diameter than the diameter of the circle defined by the legs of the first part, but the teeth are deformable to fit within 25 the circle defined by the legs of the second part. This deformation of the teeth causes them to push outwardly against said legs and to spring out into the apertures when aligned therewith.

Preferably the engaging portions (e.g. the teeth and 30 sidewalls of the apertures) of both parts are formed of a deformable material (e.g. a plastics material).

Preferably the material is sufficiently stiff that relative movement of the parts can be resisted when in the locking positions, but sufficiently resilient that it

does not snap when deformed during locking or unlocking of the parts.

According to a second aspect of the present invention there is provided 5 an assembly of automotive parts comprising: a first part and a second part which are movable relative to each other and which can be locked together to resist further relative movement when in certain predetermined positions; 10 the first part having at least a first and a second aperture, said apertures being spaced apart from each other; the second part having a plurality of teeth and gaps between adjacent ones of said teeth, the teeth being 15 deformable and extendable into said apertures when aligned therewith; each of said apertures being sized to fit a predetermined maximum number of teeth, which predetermined maximum number of teeth may or may not be 20 the same for each aperture; the spacing of the apertures being selected such that the first and second parts can be moved relative to each other into: a first position and a third position in both of 25 which positions the first aperture is aligned with a number of teeth equal to its predetermined maximum number of teeth such that said teeth extend into said first aperture such that one of said teeth abuts against a first side wall of said first aperture and one of said 30 teeth abuts against a second side wall of said first aperture thereby resisting relative movement of said first and second parts, said abutting teeth being different in said first and third positions, and wherein in said first position and said third position said

second aperture is not aligned with its predetermined maximum number of teeth; said first and third positions not being coincident with each other; and a second position, between said first and third 5 positions, in which second position the second aperture is aligned with a number of teeth equal to its predetermined maximum number of teeth such that said teeth extend into said second aperture so that a one of said teeth abuts against a first sidewall of said second 10 aperture and one of said teeth abuts against a second sidewall of said second aperture thereby resisting relative movement of said first and second parts, and wherein in said second position said first aperture is not aligned with its predetermined maximum number of 15 teeth.

Thus provision of a second aperture and appropriate selection of the aperture spacing enables the parts to be locked in an second position between the first and third positions. This allows the relative position or 20 orientation of the two parts to be determined more precisely than if there was only one aperture, as the distance (or angle) between adjacent locking positions is then not limited to the width of a tooth and the gap between adjacent teeth, but can be made smaller.

25 Further apertures may be provided to give intermediate locking positions between the first and second (or alternatively the second and third) positions.

The requirement is that for each such 'intermediate' aperture, when it is aligned with its predetermined 30 maximum number of teeth, the other apertures are not so aligned. There may also be provided further apertures for reinforcing the locking provided by existing apertures.

For example a first reinforcing aperture could be

provided which is situated such that when it is aligned with its predetermined maximum number of teeth, the first aperture is also so aligned. Thus in the first position locking can be achieved by extension of teeth into both 5 the first aperture and the first reinforcement aperture.

This may give a more secure lock, which could be useful in applications where larger forces or torques are likely to be applied to the parts, or the teeth are likely to fail. 10 The second aspect of the invention may have any of the features of the first aspect of the invention described above. For example for any or all of the apertures the predetermined maximum number of teeth may be one, although preferably it is greater than one.

15 An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 is a perspective view, is a clingon solenoid; Fig. 2 is a perspective view of a lock ring for 20 mounting on the clingon solenoid of Fig. It Fig. 3 is a perspective view of an assembly comprising the lock ring mounted on a clingon solenoid) and Figs. 4a - 4g are top down views of the lock ring 25 and clingon solenoid in seven different positions; Fig. 5 is a plan view of the lock ring; Fig. 6 is a cross-section of the lock ring along the line A-A of Fig. 5; Fig. 7 is an enlarged cross-sectional view of a 30 tooth and a portion of the lock ring; Fig. 8A is a plan view of the solenoid casing; Fig. 8B is a plan view of the solenoid casing showing the angular widths of the legs and apertures;

Fig. 9 is a cross-sectional view of the solenoid casing along the line BB of Fig. 8A; Fig. 10 is an enlarged cross-sectional view of one leg and a portion of the solenoid casing; 5 Fig. 11 is a perspective view of the assembly comprising the lock ring mounted on a clingon solenoid; Fig. 12 is a top-down plan view of the assembly shown in Fig. 11; Fig. 13 is a cross-section of the assembly along the 10 line CC of Fig. 12; and Fig. 14 is an enlarged view of a portion of Fig. 13.

Fig. 1 shows a solenoid casing 1 (e.g. a clingon solenoid) which is to be attached to a valve plate.

Conventionally, this attachment is done by ultra-sonic 15 welding, but in the present embodiment the solenoid is attached to the valve plate via lock ring 10 shown in Fig. 2. The lock ring 10 may be a separate ring which can be attached to the valve plate, or may be an integral part of the valve plate moulding.

20 Fig. 3 shows the solenoid casing 1 and lock ring 10 of Figs. 1 and 2 when assembled together with the lock ring 10 mounted on the solenoid casing 1. The two parts (the solenoid casing 1 and lock ring 10) are mounted together in such a way that they are rotatable relative 25 to each other so that their relative positioning (i.e. relative orientation) can be varied. Means are provided on the first part 1 (the solenoid) and the second part 10 (the lock ring) so that the parts can be releasably locked together and their relative orientation fixed in 30 certain predetermined positions (which in this embodiment are spaced 1 apart from each other to give a total of 360 different positions in which the two parts can be locked).

The solenoid casing 1 has an arm 2 which terminates in a head 3 of generally cylindrical shape. The top surface of the head 3 has a centrally positioned locating pin 4 and a plurality of legs 5 arranged around its 5 circumference, projecting upwardly from the top surface.

The legs 5 together define a circle and are spaced from each other by apertures 6. The side ends of the legs 5 provide sidewalls for the apertures 6 which they border.

The lock ring 10 is in the form of a ring having 10 teeth 12 projecting from one side of the ring. The teeth are arranged in a circle and gaps 11 are provided between adjacent teeth. Each tooth extends 4 around the circumference of the ring and each gap between two adjacent teeth extends 2 around the ring.

15 The lock ring 10 is mounted on the solenoid, as shown in Fig. 3 and Figs. 4a to 4g, such that the legs 5 and teeth 12 define approximate circles which are concentric with each other. The teeth 12 of the lock ring 10 when in their undeformed state form a circle 20 having a slightly larger diameter than the inner diameter of the circle defined by the legs 5, so that when the lock ring is mounted on the solenoid casing 1, teeth 12 adjacent the legs 5 are pushed in and held by the legs 5 adjacent to them. This deformation of the teeth causes 25 them to be biased slightly outwards.

Thus teeth which are aligned with an aperture 6 between adjacent legs 5 (i.e. teeth which are positioned such that they are not even partially held by the legs) extend into the aperture 6 which they are aligned with.

30 The legs 5 are themselves biased slightly inwards, so that the two parts are held together.

The legs S and the lock ring 10 are made of a deformable plastics material which is sufficiently stiff that relative movement of the lock ring 10 and clingon

solenoid 1 is effectively resisted when teeth extend into and abut against opposing sides of an aperture 6, but sufficiently resilient that parts do not snap e.g. when a tooth is pushed back out of an aperture to 'unlock the 5 lock ring 10 and the clingon solenoid 1. This locking and unlocking of the parts will now be described in more detail. Fig. 4a is a top view of the assembly comprising the solenoid 1 and lock ring 10. It shows the two parts (the 10 lock ring 10 and the clingon solenoid 1) when orientated in a first position. In this first position only the first aperture 6a is aligned with its maximum number of teeth (four). The teeth aligned withthe first aperture 6a extend into the first aperture 6a so that one of the 15 teeth 12a abuts against a first sidewall of the aperture and another of the teeth 12d abuts against a second sidewall of the aperture, the sidewalls being provided by the legs 5 bounding the aperture 6a. For illustrative purposes the aperture 6a which is aligned with its 20 predetermined maximum number of teeth in the first position is ringed in Fig. 4a.

The other five apertures 6b to 6f are not aligned with their predetermined maximum number of teeth (four for each aperture) and thus although some teeth have 25 sprung into these apertures, there is a degree of play as teeth do not abut against both sidewall of the other apertures. It is only locking by the teeth 12a and 12d abutting against the sidewalls of the first aperture 6a which locks the two parts together to resist relative 30 rotational movement thereof.

Thus if one of the teeth at the edge of the aperture 6a - tooth 12a or tooth 12d - is pushed back out of the = aperture (i.e. inwards from their locking position towards the centre of rotation), then the lock ring 10

can be rotated until another one of the apertures is aligned with its predetermined maximum number of teeth.

The aligned teeth will then spring out to lock the parts together in this position.

5 Figs 4b-4g show successive positions in which the parts can be locked by extension of teeth into the apertures. In each of these positions one, and only one, of the six apertures 6a-6f is aligned with its predetermined maximum number of teeth (four) and locking 10 is by extension of teeth into this aperture. For illustrative purposes the aperture which is aligned with its predetermined maximum number of teeth is ringed in each figures 6a-6g. The parts can be unlocked from each position by pushing teeth back out of the aperture as 15 described above for the first position. Successive positions in which the parts can be locked together (shown in figs 4a-4g) are separated from each other by 1 of rotation.

Figs 4a and 4g show successive positions in which 20 the parts can be locked by extension of teeth into the first aperture 6a, while Figs 4b-4f show positions in which the parts can be locked by extension of teeth into apertures other than the first aperture.

The relationship between the apertures and the 25 importance of their relative spacing can be best understood by consideration of Fig 4a and Fig 4g. In keeping with the terminology used in the statements of

invention above, we shall call the position shown in Fig 4a the first position and the position in Fig 4g the 30 third position.

Successive positions in which the first aperture is aligned with its predetermined maximum number of teeth (i.e. successive positions in which the parts are locked by extension of teeth into the first aperture), such as

the first position shown in Fig 4a and the third position shown in Fig 4g, are separated from each other by 6 of rotation. This separation of 6 corresponds to the sum angular 5 width of one tooth (4 ) and the angular width of a gap between two adjacent teeth (2 ); it is the minimum relative movement required to move the parts from one position in which the first aperture 6a is aligned with its predetermined maximum number of teeth to another 10 position in which the first aperture 6a is aligned with its predetermined maximum number of teeth.

Thus if there was only one aperture in the first part, lockable orientations of the parts would occur only -

every 6 of rotation. It would not be possible to fix the 15 parts in other positions.

The provision of further appropriately spaced apertures 6b-6f enables finer graduation of the locking positions. That is the further apertures allow the parts to be locked in positions between the first and third 20 positions mentioned above.

For example, (using the same terminology as the statements of invention) a second aperture 6f is spaced -

from the first aperture 6a so as to allow the parts to be locked in a second position shown in Fig 4f. In this 25 embodiment this second position is separated from the -

first position (of Fig 4a) by 5 of rotation.

The other apertures 6b-6e allow for locking in intermediate positions between the first and second o positions shown in Figs 4a and 4f. Thus the parts can be 30 locked every l of rotation.

In the second position of the assembly, shown in Fig 4f, the lock ring lO has been rotated 5 clockwise relative to the first position shown in Fig. 4a. The -

second aperture 6f is aligned with its predetermined

maximum number of teeth (four) and the teeth have sprung out to extend into the second aperture Of thereby locking the two parts in the second position. The other apertures 6a-6e and 6e-6f are not aligned with their 5 predetermined maximum number teeth in this second position. Likewise in each of the intermediate positions shown in Figs 4b-4e, only one of the apertures is aligned with its predetermined maximum number of teeth (four in each 10 case). This is important because it means that the positions are not coincident.

In each lockable position (e.g. each of Figs 4a-4g) locking of the parts is achieved by extension of teeth into the aperture aligned with its predetermined maximum IS number of teeth. This tends to happen automatically as the teeth are biased outwards when in their deformed state. By pushing teeth in from their locking positions (in which teeth are in their undeformed state) the parts can be unlocked and further rotated relative to each 20 other to the next lockable position.

Figs 4a-4g show only 6 degrees of rotation. However the parts can be rotated by a full 360 . After 360 of rotation the parts are back in the first position shown in Fig 4a and can be locked again in the first position.

25 There are however many more positions in which the parts can be locked.

It has already been mentioned that the positions in which the parts are locked by extension of teeth into the first aperture (i.e. the positions in which the first 30 aperture is aligned with its predetermined maximum number of teeth) occur every 6 of rotation. The same is true for the other apertures.

So, for example, just as rotation by 6 clockwise further from the first position shown in Fig 4a results

in the first aperture 6a again being aligned with its predetermined maximum number of teeth (as shown in Fig 4g), rotation by 6 clockwise from the second position shown in Fig if will result in the second aperture 6f 5 again being aligned with its predetermined maximum number of teeth (this position is not shown in the Figs). The same is true of anticlockwise rotation and also for the third to sixth apertures 6b-6e which provide intermediate locking positions.:: 10 As only one of the apertures is aligned with its predetermined maximum number of teeth at a time, none of these positions are coincident. Therefore, in this embodiment, each aperture enables 60 different lockable -

positions in the 360 of rotation, making a total of 360 15 different lockable positions. In this embodiment the spacing of the apertures is such that successive lockable positions are separated by l of rotation. In general it is preferable, though not necessary, for the lockable -

positions to be regularly spaced, e.g. as in this 20 embodiment.

It should now be appreciated that the separation of successive lockable positions in which a given aperture (e.g. the first aperture 6a) is aligned with its predetermined maximum number of teeth is determined by 25 the widths of the teeth and the gaps between the teeth.

Where the tooth and gap widths are uniform, the spacing of these positions (e.g. positions in which the first aperture 6a is aligned with its predetermined maximum D number of teeth) will be regular (in this embodiment -

30 every 6 ).

The separation of successive lockable positions in which the parts are locked by extension of teeth into any of the apertures (including the first and second positions and intermediate positions between the first

and second positions) will be determined by the spacing of the apertures into which the teeth extend to lock the parts. Preferably the spacing of the apertures is such that successive lockable positions occur at regular 5 intervals, as is the case in this embodiment (where lockable positions occur every 1 of rotation).

In this embodiment only one aperture is aligned with its predetermined maximum number of teeth in any one relative position (orientation) of the parts. In other 10 embodiments there may be further apertures which correspond to the one of the six apertures mentioned above and which are aligned with their predetermined maximum number of teeth at the same time as the aperture which they correspond to. Such apertures are redundant 15 from the positioning point of view as they provide for locking only in positions in which the parts can already be locked by extension of the maximum number of teeth into the corresponding aperture. However by providing an extra aperture which is aligned (and thus can be 'locked' 20 by extension of the predetermined maximum number of teeth) at the same time, they have a reinforcing function and help to provide a more secure lock.

Some features of the above embodiment will now be described in more detail with reference to Figs. 5 to 10.

25 Fig 5 is a plan view of the lock ring 10 having a plurality of teeth 12 disposed around its circumference.

Fig. 6 is a cross section of the lock ring 10 along the line A-A of Fig. 5. As can be seen in Fig. 6 the teeth extend upwardly and radially outwards from the bottom of 30 the lock ring 10. This is shown in more detail in Fig. 7 which is an enlarged cross-sectional view showing a single tooth 12 in its undeformed state and a portion of the lock ring circumference 10 adjacent to the tooth 12.

The tooth 12 projects radially outward from the

circumference of the lock ring 10 so that there is a gap 200 between the tooth 12 and the circumference of the lock ring when the tooth 12 is in its un-deformed state.

When the tooth 12 is deformed (e.g. by pressing the tooth 5 12 against a leg 5 of the solenoid casing) it is pushed against the lock ring 10 so there is no gap between the two and the outer wall 120 of the tooth is then substantially parallel to the outer wall 100 of the lock ring. This is achieved by the shaping of the tooth 12 10 and the angle at which it projects outwardly from the lock ring 10, in the present embodiment the tooth projects outwardly at an angle of approximately 80 to the horizontal (10 from the vertical outer circumferential wall 120 of the lock ring) when in its 15 undeformed state.

Fig. 8a is a plan view from above of the solenoid casing 1.

Fig. 8b is a further plan view showing the angular width of each gripper leg 5 and the apertures 6 between 20 adjacent gripper legs. Each aperture 6 has an angular width of 22 , but the gripper legs 5 which separate adjacent apertures have different angular widths from each other in order to offset the apertures from each other by the necessary amount to achieve the desired 25 spacing of locking positions.

Fig. 9 is a cross sectional view of the solenoid casing along the line BB of Fig. 8a. It shows that each gripper leg 5 extends upwardly from the circumference of the top surface of the solenoid casing head 3 and has a 30 flange 51 at its top end extending radially inwardly.

This flange 51 helps to hold the teeth in place when they are in their deformed state abutting against the gripper leg 6. In this embodiment, as shown in Fig. 10, the -

flange 61 extends at an angle of 100 to the main body of

the leg 6, rather than being perpendicular thereto. The reason for this is that it is easier for the teeth 12 to -

click into place when the flange 51 is at an angle -

slightly greater than 90 to the rest of the gripper leg 5 5. It should also be noted from Fig. 5 that each tooth 12 has opposite sides adjacent the gaps 11 on either side = of the tooth. These sides are substantially perpendicular to each other rather than tapering inward 10 towards the centre of the lock ring 10. While it would -

be possible for the teeth to have sides aligned with radial lines of the lock ring (i.e. tapering radially inwardly) this would cost more to manufacture.

Figures 11-14 show the solenoid casing 1 and lock 15 ring 10 when assembled together with the lock ring 10 mounted on the solenoid casing 1. Fig. 11 is a perspective view of the solenoid casing 1 and lock ring 10 in a first position in which the predetermined maximum -

number of teeth (4) are aligned and extend (in their 20 undeformed state) into the first aperture 6a.

Fig. 12 is a top down plan view of the lock ring-

solenoid casing assembly. It shows that some of the teeth 12 are in their undeformed state and extend into the various apertures 6a-6f. The other teeth 12 are held 25 back in the deformed state by the clingon solenoid's legs -

5. The lock ring 10 and solenoid casing 1 are in the -

first position so that only the first aperture 6a is aligned with its predetermined maximum number of teeth -

(4). These aligned teeth are in their undeformed state 30 then extend into the aperture 6a. -

Fig. 13 is a cross-section along the line C-C of Fig. 12. The crosssection passes through the apertures 6c and Of and two teeth 12p and 12q on opposite sides of -

the lock ring 10. The tooth 12p straddles the junction

between the aperture 6c and the leg 5 to one side of the aperture 6c. As such, it is not properly aligned with the aperture 6c, as part of the tooth abuts against the inner circumferential wall of the leg 5 and is thus held S in its deformed position so that it does not extend radially outwardly into the aperture 6c. Likewise, the tooth 12q straddles the junction between the aperture Of and the leg 5 to one side of the aperture 6f; it is thus kept in its deformed state by abutment against the inner D 10 circumferential wall of the leg 5. The teeth 12p and 12q are held in the deformed states by the legs 5 as shown in Fig. 13.

Fig. 14 is an enlarged view of the part of Fig. 13 which shows the leg 5 and the tooth 12p. In its deformed 15 state the tooth 12p is pushed up against the outer circumferential wall 100 of the lock ring 10, so that the gap 200 between them (see Fig. 7) is closed. The outer wall 120 of the tooth 12p is substantially parallel to the outer wall 100 of the lock ring. The tooth 12p clips 20 into place and is partially held by flange 51 of the leg 5 which extends over the upper end of the tooth 12p.

The present invention has been illustrated by way of the above described embodiment. However, variations thereto will be apparent to those skilled in the art.

25 For example, the number of apertures can be varied (as long as there are at least two) and the spacing, aperture width, tooth and gap widths can also be varied.

Furthermore while in the above described embodiment the first part fits inside the second part, it would be 30 possible to reverse this situation so for example the teeth of the second part defined a circle of larger radius than the apertures of the first part with the teeth being biased inwards to spring into the apertures when aligned therewith.

Claims

Claims

1. An assembly of automotive parts comprising: a first part and a second part which are movable 5 relative to each other and which are lockable together to resist further relative movement when in certain predetermined positions; the first part having at least a first and a second aperture, said apertures being spaced apart from each 10 other; the second part having a plurality of teeth and gaps between adjacent ones of said teeth, the teeth being deformable and extendable into said apertures when aligned therewith; 15 each of said apertures being sized to fit a predetermined maximum number of teeth, which predetermined maximum number of teeth may or may not be the same for each aperture; the spacing of the apertures being selected such 20 that the first and second parts are moveable relative to each other into: a first position in which the first aperture is aligned with a number of teeth equal to its predetermined maximum number of teeth such that said teeth extend into

said first aperture so that one of said teeth abuts against a first side wall of said aperture and one of said teeth abuts against a second side wall of said aperture thereby resisting relative movement of said 5 first and second parts, and wherein in said first position said second aperture is not aligned with its D predetermined maximum number of teeth; and a second position in which the second aperture is aligned with a number of teeth equal to its predetermined 10 maximum number of teeth such that said teeth extend into said second aperture so that one of said teeth abuts against a first sidewall of said second aperture and one -

of said teeth abuts against a second sidewall of said second aperture thereby resisting relative movement of 15 said first and second parts, and wherein in said second position said first aperture is not aligned with its predetermined maximum number of teeth.

2. An assembly according to claim 1 wherein each said 20 aperture is sized to fit a predetermined maximum number of teeth greater than one.

3. An assembly according to claim 1 or claim 2 wherein the assembly is configured such that said first and

second parts are ratably movable relative to each other, said first and second positions corresponding to different degrees of rotation.

5 4. An assembly according to any one of the preceding claims wherein the first and second parts are between a solenoid and a valve plate. = 5. An assembly according to any one of the above claims 10 wherein said first and second parts are movable relative to each other into a third position, in which third position the first aperture is aligned with a number of teeth equal to its predetermined maximum number of teeth such that said teeth extend into said first aperture so 15 that one of said teeth abuts against a first side wall of said aperture and one of said teeth abuts against a second side wall of said aperture thereby resisting relative movement of said first and second parts, and wherein in said third position said second aperture is 20 not aligned with its predetermined maximum number of teeth; the tooth or teeth abutting against the side walls of said first aperture when the parts are in the third position being different ones to the tooth or teeth which

abut against the side walls of said first aperture when the parts are in the first position.

6. An assembly according to any one of the above claims 5 wherein the parts are configured such that in addition to said first and second positions the first and second parts are movable relative to each other into a plurality of further positions in which the parts are lockable by extension of the predetermined maximum number of teeth 10 into said first or second aperture.

7. An assembly according to claims 5 or 6 wherein the -

parts are configured such that the positions in which the parts are lockable by extension of the predetermined 15 maximum number of teeth into the first or second aperture occur at regular intervals.

8. An assembly according to any one of the above claims wherein the teeth on the second part are a continuous 20 array of teeth.

9. An assembly according to any one of the above claims wherein the teeth have uniform widths and the gaps between the teeth also have uniform widths.

10. An assembly according to any one of the above claims wherein the first part has one or more further apertures for providing one or more intermediate positions, between 5 said first and second positions, in which intermediate positions the parts are lockable together by extension of a predetermined maximum number of teeth into one of said = further apertures.

10 11. An assembly according to any one of the above claims wherein the first part is provided with one or more reinforcing apertures into which the teeth of the second part are expendable to lock the first and second parts together, the reinforcing apertures being sized to fit a 15 predetermined maximum number of teeth and corresponding to the first aperture or the second aperture, so that a reinforcing aperture corresponding to the first aperture is aligned with its predetermined maximum number of teeth when the first aperture is aligned with its predetermined 20 maximum number of teeth, and a reinforcing aperture corresponding to the second aperture is aligned with its predetermined maximum number of teeth when the second aperture is aligned with its predetermined maximum number of teeth.

12. An assembly according to any one of the above claims wherein the teeth of the second part are biased against the first part such that they spring into an aperture of 5 the first part when aligned with said aperture.

13. An assembly according to any one of the above claims wherein the first and second parts are ratably moveable relative to each other about a common axis and wherein 10 said teeth and apertures are arranged as concentric circles. 14. An assembly according to any one of the above claims wherein the first part has a plurality of legs and gaps 15 between adjacent legs form the apertures in the first part. 15. An assembly according to claim 14 wherein when in their un-deformed state, the teeth define a circle of a 20 slightly larger diameter than the diameter of a circle defined by the legs of the first part, and wherein the teeth are deformable to fit in apertures in the circle defined by the legs of the first part.

16. An assembly according to any one of the above claims wherein the teeth and sidewalls of the apertures of both parts are formed of a deformable material which is sufficiently stiff that relative movement of the parts 5 can be resisted when the parts are in a locking position, but sufficiently resilient that the teeth do not snap when deformed during locking or unlocking of the parts.

17. An assembly substantially as described herein with 10 reference to the accompanying figures.