GB2487761A

GB2487761A - Sliding supports

Info

Publication number: GB2487761A
Application number: GB1101866.0A
Authority: GB
Inventors: John Dominic Cole
Original assignee: T & L Systems Ltd
Current assignee: T & L Systems Ltd
Priority date: 2011-02-03
Filing date: 2011-02-03
Publication date: 2012-08-08
Anticipated expiration: 2031-02-03
Also published as: WO2012104650A1; GB2487761B; GB201101866D0

Abstract

A sliding support connects two components of a product so that one can slide relative to the other. A first sliding member 2 has a slot 20 and a second sliding member (8, Fig. 8) has a hole (36, Fig. 3) aligned with the slot 20. A control block 24 fits tightly through the hole 36 and locates in the slot 20 so that the control block 24 is constrained to slide along the slot 20 in the first sliding member, carrying the second sliding member with it. A support bar 40 may be provided between the first and second sliding members 2, 8 and may carry detent structures 48 to engage with a lug 26 on the control block 24 in order to define intermediate rest positions along the slot 20. The control block 24, slot 20 and hole 36 can be manufactured to high tolerances to control the relative movement of the respective parts precisely, so other parts (such as bearings) between the first and second sliding members can be made and assembled with lower precision.

Description

TITLE

Sliding supports

DESCRIPTION

S Technical field

The invention relates to sliding supports, which provide a mechanical interface between two components of a product so that one component can slide relative to the other component in a controlled manner. A typical application for such supports is in the sliding arm rest of a motor car or other passenger vehicle.

Backgjound of the invention Sliding supports of the kind relevant to the present invention comprise a pair of sliding members, which have means for attaching them to the moving components of the product in which the sliding support is to be installed (e.g. respectively to the fixed arm and to the movable arm rest of a vehicle). The sliding members are configured to be able to slide relative to one another in both directions along a defined axis, which in this specification is called the X-axis. (In the example of an arm rest, the X-axis is the generally horizontal axis along the length of the arm rest.) In one type of sliding support an outer one of the sliding members forms a channel parallel to the X-axis; an inner one of the sliding members is located within the channel and is constrained by bearings to be able to move only along the length of the channel. An example of such a sliding support is disclosed in international patent application WO 2007/017688 Al. In that example the engagement between the inner and outer sliding members is via a set of ball bearings.

Control of the relative positioning between the two sliding members is critical to the success of a sliding support. They must be able to move smoothly and easily relative to one another along the X-axis. However, they should be prevented from significant relative movement in the Y-axis (i.e. the direction of the width of the channel) or the Z-axis (i.e. the direction of the thickness of the channel, which in the example of an arm rest is a substantially vertical direction). Any freedom of movement in the Y and Z directions can result in the user of the product sensing that the components are loosely attached and it also gives rise to the potential for the sliding members to rattle together, for example due to the vibration of a moving vehicle. The movement between the sliding members in the Y and Z directions therefore needs to be tightly controlled, without interfering with their movement in the X direction, and taking due account of the materials and manufacturing tolerances of the parts from which the sliding support is made.

Although sliding members of the support must move smoothly and easily along the X-axis, some damping of that movement is desirable in order to give the user precise io control over it. In the sliding support disclosed in WO 2007/017688 Al, an oil-filled rotary damper is provided between the sliding members.

It is preferred that when the limit of the movement between the sliding members along the X-axis in each direction is reached, the movement is stopped soundlessly and not too abruptly. As an exception to the general requirement that the movement along the X-axis should be smooth, predetermined intermediate positions may be defined at which the movement naturally pauses so that the user can recognize and return to those positions when adjusting the sliding components, and so that the components will remain in one of the pre-defined positions under normal use of the product, i.e. when the user is not exerting pressure to adjust its position.

Summary of the invention

The invention provides a sliding support as defined in claim 1.

The invention further provides a method of assembling a sliding support as defined in claim 13.

Preferred but non-essential features of the invention are defined in the dependent claims.

The control block is the key to the invention, It substantially determines the relationship between the first and second sliding members. More specifically, it fixes their relative positions along the Y-axis; it fixes their relative positions in one direction along the Z-axis; and it mediates their sliding relationship along the X-axis.

The control block can be formed to the required tolerances more easily and cheaply than the bearings that undertook some of these roles in prior art designs.

The drawings Figure 1 is a perspective view of the upper side of a sliding support in accordance with the invention.

Figure 2 is an end view of the sliding support of Fig. 1.

io Figure 3 is a plan view of the underside of the sliding support of Fig. I. Figure 4 is a plan view similar to Fig. 3 but with the platen removed.

Figure 5 is a perspective view of the underside of the sliding support with the platen removed.

Figure 6 is a perspective view of the support bar of the sliding support of Fig. 1.

is Figure 7 is a perspective view of the control block of the sliding support of Fig. 1.

Figure 8 is a perspective view of the platen and control block of the sliding support of Fig. 1.

Detailed description

The drawings illustrate one example of a sliding support according to the invention, which is designed to support the sliding arm rest of a motor vehicle. A first sliding member 2 is formed as a shallow channel consisting of a base plate 4 with in-turned side walls 6. A second sliding member 8 is formed as a platen consisting of a base plate 10 with out-turned side walls 12. As seen in Fig. 8, the side walls 12 of the second sliding member 8 need not extend over the whole length of the base plate 10.

The second sliding member 8 fits within the first sliding member 2, with the out-turned side walls 12 of the platen being retained by the in-turned side walls 6 of the channel. Solid bearings 14 formed from a low friction material are provided on the out-turned side walls 12 of the second sliding member 8 and engage the in-turned side walls 6 of the first sliding member 2 so that the platen of the second sliding member 8 can easily slide backwards and forwards along the length of the channel formed by the first sliding member 2.

The first sliding member 2 has projecting hooks 16 and screw holes 18 for attaching it to one of the components that are to be connected by the sliding support -in this case a moving arm rest (not illustrated). The second sliding member 8 will similarly be attached to the other one of the components that are to be connected -in this case the fixed arm piece of a vehicle seat (not illustrated). It will be understood that the drawings illustrate just one possible orientation and that the sliding support would function equally well if inverted so that the second sliding member 8 was at the top.

An elongated, rectangular slot 20 is formed through the base plate 4 of the first sliding member 2, parallel to the channel. As shown, the slot 20 does not have to be formed on the centreline of the base plate 4. The length of the slot 20 defines a sliding axis (X); the width of the slot 20 defines a transverse axis (Y); and the direction perpendicular to the X-and Y-axes (i.e. the direction through the slot 20, perpendicular to the base plate 4) is defined as an orthogonal axis (Z). As shown by the arrows 22 in Fig. 1, these axes merely indicate directions relative to the sliding support. References in this specification to movement along an axis mean movement in the positive or negative direction parallel to that axis but not along any particular line. All movements between two parts should be understood as relative: it does not matter which part is moving and which part is fixed.

A control block 24, best seen in Fig. 7, has a generally cuboidal shape with a width (measured along the Y-axis) substantially equal to the width of the slot 20. Two lugs 26 project in the transverse direction from the lower portions (as viewed in Fig. 7) of opposite side walls of the control block 24. The upper part 28 of the control block 24, where the lugs 26 are not present, fits into the slot 20 of the first sliding member 2 as seen in Fig. 1. Upward facing surfaces 30 of the lugs 26 bear against the base plate 4 of the first sliding member 2 on each side of the slot 20 to limit the movement of the control block 24 along the Z-axis so that the upper surface 32 of the control block 24 does not project above the upper surface 34 of the base plate 4.

A hole 36 is formed through the base plate 10 of the second sliding member 8. The hole 36 is sized and shaped to match the outline of the control block 24 when viewed in the Z-direction so that the control block 24 can pass through the hole 36 with minimal clearance and then be held by the hole 36 against movement in the X-Y plane of the base plate 10. It should be noted that to achieve these functions -to allow the control block 24 to pass through but to hold it securely -the shape of the hole 36 need not match the outline of the control block 24 exactly: for example the hole 36 could be made larger than the outline in some areas while still holding the control block 24 in other areas such as its corners. The positioning of the hole 36 in the base plate 10 is such that, when the second sliding member 8 is located in the channel of the first sliding member 2, the hole 36 in the second sliding member 8 is aligned with the slot 20 in the first sliding member 2. With the first and second sliding members 2,8 assembled, the control block 24 can therefore be pushed through the hole 36 to engage the slot 20 as previously described.

A support bar 40 (shown in Fig. 6) is located in the sliding support between the first and second sliding members 2,8. The support bar 40 is elongated and carries a series of fixing tabs 42 along its length, which can be engaged with a matching series of fixing apertures 44 in the base plate 4 of the first sliding member 2 in order to fix the support bar 40 to the first sliding member 2 alongside the slot 20. A lower surface 46 of the support bar 40 (referring still to the orientation of the device shown in Fig. 1) bears against an upper surface of the base plate 10 of the second sliding member 8 to control the separation between the first and second sliding members 2,8.

Spaced at intervals along the support bar 40 are detents 48, each of which comprises a pair of flexible arms 50 that extend towards one another across the opening of a recess 52 in the support bar 40, and also extend slightly away from the recess 52 towards one edge of the slot 20. As the control block 24 is moved along the slot 20 one of its projecting lugs 26 engages the first arm 50 of a detent structure 48 and ao deflects it towards the recess 52 to allow the control block 24 to pass. As the lug 26 passes the end of the deflected arm 50, the arm springs back and the lug 26 becomes held in the opening of the recess 52 between the ends of the pair of flexible arms 50, thereby temporarily halting the progress of the control block 24 along the slot. The curved profile of the lug 26 is designed such that it is possible to free the lug 26 from the detent 48 by exerting increased force along the X-axis, thereby deflecting the second arm 50 out of the way. The effect is that, in the movement of the control block 24 along the slot 20, the detents 48 define positions at which the movement can naturally be paused, and at which the sliding support can rest during use of the product until an increased force is applied by the user to adjust its position. The force required to escape from the detent should therefore be larger than the forces exerted along the X-axis during normal use, e.g. by a user leaning on the arm rest, but not so io large that it is difficult to move the arm rest when the user does wish to adjust its position.

As illustrated, the support bar 40 has three detents 48. One is at each end of the stroke through which the control block 24 can move along the slot 20 and the other is at the mid-point of the stroke. Clearly more detents could be provided if it was desired to define more rest positions, or their positions could be changed.

The provision of a detent 48 at each end of the stroke provides a controlled termination to the movement of the control block 24 along the slot 20. As the control block 24 reaches an end 54 of the slot 20, it is caught by one of the detents 48 and the movement is naturally paused. Escape from the detent 48 by further movement of the block 24 in the same direction is prevented by contact between an end face 56 of the control block 24 and the end 54 of the slot. The slot 20 is typically cut from sheet metal and the material of the control block 24 is typically a plastic, which can be chosen such that collisions between the block 24 and the end 54 of the slot 20 occur substantially without sound and without damage. However, the final detent 48 ensures that such collisions should not happen at high speed and it improves the feel of the sliding mechanism for the user at the end of its stroke.

In the illustrated embodiment of the invention, a single support bar 40 is provided, which carries detents 48 along just one side of the slot 20 for engagement with just one of the lugs 26 of the control block 24. It can readily be envisaged, for example with reference to Fig. 4, that a second, similar support bar (not illustrated) could be provided on the other side of the slot 20 to carry detents for engagement with the other lug 26 of the control block 24. The set of detents on the second support bar can be at positions matching those on the first, whereby at each such position the control block 24 is held symmetrically by detents 48 on both sides of the slot 20.

Alternatively, the set of detents on the second support bar can be at intermediate positions between those on the first, whereby as the control block 24 moves along the slot 20 it is held alternately by detents 48 on one side of the slot then the other. For added strength and stability, the two support bars can be linked at their respective io ends to form a ring structure surrounding the slot 20.

In the absence of a second support bar as just described, the second lug 26 of the control block 24 is not essential. However, some sort of lateral projection from the block 24 is preferred in order to provide an upper surface that can bear against the is base plate 4 on the second side of the slot 20. The shape of that projection need not mirror the shape of the lug 26 on the first side.

It can also be envisaged that the locations of the detents 48 and the lugs 26 could be exchanged, i.e. a detent mechanism formed on one side of the control block could engage with a set of lugs at fixed positions arranged along a support bar. In this case, the control block 24 might be able to pass through the hole 36 in the second sliding member 8 only when the arms of the detent structure are deflected inwards. The control block would thereafter be prevented by the arms -which have sprung out again -from being removed through the hole 36, which would make it more secure but would render disassembly of the sliding support more difficult.

The illustrated sliding support is assembled by fixing the support bar 40 to the first sliding member 2; sliding the second sliding member 8 into the channel of the first sliding member 2; then inserting the control block 24 through the hole 36 in the second sliding member 8 to engage in the slot 20 of the first sliding member 2 and lock the whole structure together. When the second sliding member 8 is attached to one of the moving components of the product of which the sliding support is to form a part (not illustrated), the hole 36 will be blocked so the control block 24 cannot then be withdrawn.

The slot 20 constrains the control block 24 to move only along the sliding axis (X) and prevents it from moving along the transverse axis (Y). The upper surfaces 30 of the lugs 26 bear against the base plate 4 on each side of the slot 20 to limit movement of the control block 24 along the orthogonal axis (Z). The engagement between the hole 36 and the control block 24 prevents relative movement between the control block 24 and the second sliding member 8 in the X-Y plane so the second sliding member 8 is constrained to move only with the control block 24 along the sliding axis (X). (In fact, in the orientation and use of the sliding support described herein, it is the second sliding member 8 that is fixed and the first sliding member 2 that moves, but that is just a difference of frame of reference and does not change the principles of the invention.) The first and second sliding members 2,8 are preferably formed by stamping from steel sheet. This allows the slot 20 and the hole 36 to be shaped and positioned with great precision. The control block 24 is preferably formed from a relatively hard plastic with low friction and good wear properties. Again, this can be moulded with great precision (e.g. a tolerance of 0.1mm). The width of the control block 24 can be matched to the width of the slot 20 with sufficient precision to control the level of friction between the block 24 and the slot 20, whereby a desired level of damping of their relative movement can be obtained without the need for a separate damper.

Because the alignment between the two sliding members 2,8 is precisely determined by the control block 24, it is not necessary to manufacture the other parts of the device with equal precision. In particular, the solid bearings 14 that provide guidance and support for the out-turned side walls 12 of the second sliding member 8 relative to the in-turned side walls 6 of the first sliding member 2 do not need to control the alignment and do not need to be formed with high precision, which is difficult to do.

A clearance fit of 2mm between the bearings and the side walls may be adequate.

Because the control block 24 does not protrude fully through the slot 20, it is not essential that the slot 20 should pierce the full thickness of the first sliding member 2.

An equivalent function could be served by a shallow channel formed in the base plate 4 of the first sliding member 2 or by a pair of guide walls standing proud of the base plate 4.

Claims

CLAIMS1. A sliding support comprising: a first sliding member; a second sliding member; and a control block; wherein the first sliding member has a slot that defines a sliding axis (X) along the length of the slot, a transverse axis (Y) across the width of the slot, and an orthogonal axis (Z) perpendicular to the sliding axis (X) and to the transverse axis (Y); wherein the control block is located in the slot of the first sliding member, the control block having a width that is substantially equal to the width of the slot so that the control block can move relative to the first sliding member along the sliding axis (X) but not along the transverse axis (Y); and wherein the control block is engaged by the second sliding member such that the control block cannot move relative to the second sliding member in the plane defined by the sliding axis (X) and the transverse axis (Y).
2. A sliding support according to claim 1, wherein the control block is engaged by the second sliding member by being located in a hole in the second sliding member.
3. A sliding support according to claim 2, wherein the control block can pass through the hole in the second sliding member in the direction of the orthogonal axis (Z).
4. A sliding support according to any preceding claim, wherein the control block has at least one lug that projects beyond the slot along the transverse axis (Y), a surface of the lug engaging a surface of the first sliding member to limit relative movement between the control block and the first sliding member in one direction along the orthogonal axis (Z).
5. A sliding support according to claim 4, wherein the control block has at least two of the lugs, which project in opposite directions along the transverse axis (Y).
6. A sliding support according to claim 4 or claim 5, further comprising at least one detent arranged alongside the slot to engage the lug of the control block releasably when the control block reaches a predetermined position along the slot.
7. A sliding support according to claim 6, further comprising a support bar that is fixed relative to the first sliding member and is arranged alongside the slot, the support bar carrying a plurality of the detents to define respective predetermined positions.
8. A sliding support according to claim 7, wherein at least one of the predetermined positions is the position of the control block when it reaches an end of the slot.
9. A sliding support according to claim 7 or claim 8, wherein the support bar is mounted between the first and second sliding members.
10. A sliding support according to claim 9, wherein the support bar has a first surface that bears against the first sliding member and a second surface that bears against the second sliding member, whereby the support bar defines a minimum separation between the first and second sliding members.
11. A sliding support according to any preceding claim, wherein one of the slide members is in the form of a channel with in-turned sidewalls; and the other of the slide members is in the form of a platen, opposing edges of which are retained in the channel by the in-turned sidewalls.
12. A sliding support according to claim 11, further comprising solid bearings between the edges of the platen and the adjacent sidewalls.

-12 -
13. A method of assembling a sliding support, comprising: locating a first sliding member that has a slot in relation to a second sliding member that has a hole, such that the hole is aligned with the slot; and passing a control block through the hole in the second sliding member to engage with the slot in the first sliding member; wherein the control block has a width that is substantially equal to the width of the slot so that the control block can move relative to the first sliding member along a sliding axis (X) defined by the length of the slot but not along a transverse axis (Y) defined by the width of the slot; and wherein the control block fits in the hole such that the control block cannot move relative to the second sliding member in the plane defined by the sliding axis (X) and the transverse axis (Y).
14. A method of assembly according to claim 13, wherein the control block has at least one lug that projects beyond the slot along the transverse axis (Y), and wherein the step of passing the control block through the hole in the second sliding member to engage with the slot in the first sliding member continues until a surface of the lug engages a surface of the first sliding member.
15. A method of assembly according to claim 14, ftirther comprising a preliminary step of mounting a support bar alongside the slot of the first sliding member, the support bar carrying a plurality of detents suitable for releasably engaging the lug of the control block when the control block reaches a predetermined position along the slot.
16. A method of assembly according to any of claims 13 to 15, wherein one of the slide members is in the form of a channel with in-turned sidewalls and the other of the slide members is in the form of a platen; and wherein the step of locating the second sliding member in relation to the first sliding member comprises introducing the platen into the channel such that opposing edges of the platen are retained in the channel by the in-turned side walls.-13 -
17. A sliding support substantially as described herein with reference to the drawings.