TRACK FOR SLIDING CLOSURE AND MECHANISM COMPRISING SUCH A TRACK

Abstract: A track assembly for a sliding closure member com­ prising a track (12) extending in a longitudinal direction, a support arm (10) mounted at one end in the track (12) for travelling movement along the track (12) by a connection (17) which retains the arm (10) generally perpendicular to the track (12) during part of the travelling movement and permits rotation of the arm (10) about an axis perpendic­ ular to the common plane of the track (12) and arm (10) in one end region of the track, the connection (17) com­ prising a ball roller (20) mounted on the arm (10) for rol­ ling movement along the track (12) when the arm (10) is generally perpendicular to the track (12) and permitting rotation of the connection (17) about the axis perpendic­ ular to the common plane of the arm (10) and the track (12), and means for engaging the connection to prevent such rotation when the connection (17) is not positioned in the end region of the track (12).

Description: PATENS ACT 1977 SPECIFICATION TITLE TRACK FOR SLIDING CLOSURE. DESCRIPTI0N. This invention relates to track assemblies for sliding closure members, in particular for sliding vehicle doors. In one known type of sliding closure system used widely for vehicle doors, when closed the external surface of the door lies flush with the external surface of the surrounding frame. When the closure is opened its initial movement is generally in a direction perpendicular to the plane of the aperture so that the closure is moved clear of the surrounding frame. The closure is then moved in a direction parallel to the plane of the aperture to allow entry into the aperture. In order to allow this movement, the closure is supported on a number of track assemblies, one of which includes a support arm mounted in a track by a connection which retains the support arm generally perpendicular to the track during the movement of the closure parallel to the plane of the aperture, and permits rotation of the arm about an axis perpendicular to the common plane of the track and arm in one end region of the track to allow the closure to move into and out of the aperture in a direction perpendicular to the plane of the aperture. Such track assemblies have included at least two sets of bearings one of which is effective to carry the closure member on the track, the other of which carries the support arm and permits rotation thereof in as the closure enters or leaves the aperture. The construction of such track assemblies is relatively complicated and expensive. As a result, it has become the usual practice to incorporate only one such track assembly in a sliding door assembly, the remaining track assemblies having rigidly eerpeetedLrsupport arms which travel along a track having arcuate end regions. The end regions of track assemblies of this type project outside the plane of the aperture. COfl#'LCflt4# in vehicles, the track assemblies encroach into the passenger or storage area of the vehicle, where they occupy useful space and are susceptible to damage. In accordance with the present invention we provide a track assembly for a sliding closure member comprising track extending in a longitudinal direction ,a support arm mounted at one end in the track for travelLing move- nt along the track by a connection which retains the arm generally perpendicular to the track during part of the travelling movement and permits rotation of the arm about an axis perpendicular to the common plane of the track and arm in one end region of the track, characterised in that tha connection comprises a ball roller mounted on the arm for rolling movement along the track when the arm is generally perpendicular to the track, and permitting rotation of the connection about the axis perpendioiilar to the common plane of the arm and the track, and means for engaging the connection to prevent such rotation when the connection is not positioned in the end region of the track. The ball roller in the connection between the arm and the track thus acts as a bearing for the arm in both the movement along the track and the rotation of the arm in the end region of the track. As a result, the construction of the assembly is simplified and its cost reduced. Although the track assembly can be used in combination with conventional track assemblies having arcuate end regions and fixed support arms, -the simplicity of its design enables it to be used in a sliding closure mechanism in which all the track assemblies are identical. The invention therefore specifically includes a sliding closure mechanism, especially a vehicle body door, comprising a frame defining an aperture, a closure member mounted for sliding movement into and out of the aperture and connected to the frame by two or more, preferably three, slidable connections at least one, and preferably each of which comprises a track assembly in accordance with the invention. Since the tracks can be straight it may be mounted either on the door or on the frame without encroachment into a passenger or load compartment. In the preferred embodiment of the invention, the closure member is supported by three track assemblies according to the invention, the tracks of two of which are mounted on the frame, the track of the third track assembly being mounted on the door. In order to provide a positive control over the movement of the arm in the end region of the track, the assembly preferably includes means engagable with the connection when the arm is in the end region of the track for effecting a rolling movement of the arm along the track in the common plane of the arm and the track, that is to say, for rotating the connection about the axis perpendicular to the common plane whilst the connection moves along the end region of the track. Conveniently the means for producing this rolling movement of the arm comprises a rack which is fixed relative to the track at least when the connection is in the end region at the track, and engagable with a pinion portion on the connection when the connection is in the enn regior of the track. Preferably the pinion portion is positioned such that it engages the rack at a point diametrically opposite the arm relative to the axis perpendicular to the said common plane when the arm lies parallel to the track in the end region of the track so that initial opening forces in the longitudinal direction produce a maximum moment about the said axis. In one embodiment of the invention the pinion portion ts defined by circumferential grooves on the ball roller. In another embodiment the pinion portion is formed by teeth on a cage in which the ball roller is rotatably mounted. The rack may be permanently fixed relative to the track. In the preferred embodiment however, the rack is mounted on the connection for movement therewith along the track, means being provided for retaining the rack in a fixed position relative to the track when the connection is in the end region of the track. Any suitable ieans may be adopted for preventing the connection from rotating about the axis perpendicular to the common plane of the arm and track. For example the ball roller may include a circumferential groove which engages with a longitudinally extending ridge in the track. Where the rack is carried by the connection, the rack itself may be constructed to prevent such rotation of the connection when the connection does not lie in the end region of the track. Thus, in the preferred embodiment of the invention, the rack is mounted for rocking movement relative to the track and rotation of the connection about the axis perpendicular to the common plane of the track and the arm rocks the rack between a locking position, in which the rack prevents the foiling movement of the arm, and a releasing position in which the arm can roll along the track, the rack being prevented from entering the releasing position by engagement with a wall portion of the track when the connection is not positioned in the end region of the track. Various embodiments of the invention will now be described, by way of example only, with reference to the drawings, in which: Figure 1 is a perspective view of a sliding door mechanism of a motor vehicle incorporating three track assemblies according to this invention; Figure 2 is a plan of the mechanism of Figure 1; Figure 3 is a plan, partly in cross-section of one of the track assemblies incorporated in the sliding door mechanism of Figures 1 and 2; -# #'## Figures 4 to 6 are views similar to Figure 3 showing the track assembly in a different configuration. Figure 7 is a partial vertical cross-section of the track assembly taken along line VI - VIII of Figure 3. Figure 8 is a perspective view of an alternative track assembly in accordance with the invention; and Figure 9 is a plan, partly in cross-section of a further alternative track assembly in accordance with the invention: Figure 10 is a partial end view of the assembly of Figure 9; and Figure 11 is a part-sectional side view of the assembly of Figure 9. Referring to the drawings, Figures 1 and 2 illustrate a sliding door mechanism suitable for incorporation in the side wall of a motor van. The side wall includes a frame 1 defining a rectangular aperture 3. A sill and step 4 lie along the bottom wall of the aperture and lead into a passenger or storage compartment. A door 5 is mounted for sliding movement on the frame 1 by means of three similar track assemblies 6, 6a a and 6b. In its open position, illustrated in full lines, the door 5 lies parallel to and adjacent the paerture 3; in its closed position, illustrated in broken lines in Figure 2, the door 5 lies within the aperture 3 with its external surface flush with the side wall of the van. Each track assembly 6, 6a 6b comprises a support arm 10, 1Oa, 10b and a track 12, 122 12b. Each support arm is mounted at one end in the track by a connector 13, 132 13b and is pivotally connected at its other end to the frame 1 or the door. The first track assembly, 6, is positioned along the upper edge of the aperture 3 with its track mounted in the frame 1 and its support arm 10 is pivotally connected to the upper co ner of the door 5 adjacent the left-hand edge 14 thereof as seen in the drawings. The second track assembly 6a also has its track mounted in the frame 1 and is positioned to one side of the aperture 3. In the embodiment illustrated the track is positioned at about the mid point of the aperture. The track may however be positioned at any point adjacent the aperture, for example, towards the top thereof. In any event, the support arm 10a of the assembly is pivotably connected to the door 5 adjacent the right hand edge 15 of the door 5. The third track assembly 6b is positioned along the lower edge of the door with its track mounted in the door 5, the support arm 10b being pivotably connected to the frame 1 in the lower right-hand corner of the aperture. Since the track 12e is mounted in the door rather than on the lower edge of the aperture 5, the track is protected from damage during loading of the vehicle compartment. The first track assembly 6 will be described in more detail with reference to Figures 3 to 5. The second and third assemblies 6a and 6b are of similar construction and need not therefore be deecribed in detail. Referring to Figures 3 to 7, the track 12 comprises a straight longitudinal extending body of uniform corss-section which is conventiently formed by extrusion. A slot 16 (Fig. 7) runs along the length of the body and receives a connector, indicated generally at 17, mounted on one end of the support arm 10. The end region of the track includes a flange 15 which is pressed out to reveal an aperture 19 on the side of the flange further from the end of the track 12. The connector 17 comprises a cage 18 in which a ball roller 20 is mounted for rotation about an axis A which is generally at 90 to the longitudinal direction of the track when the support arm extends generally perpendicular to the track, as illustrated in Figure 3. The ball roller 20 is accommodated between two channel of portions 21, 211 the track 12 which are shaped to conform to the spherical surface of the ball roller 20 so that the connection 17 can also rotate about an axis B perpendicular to the common plane of the support arm 10 and the track 12 (see Fig. 7). The cage 18 (Fig. 4) defines a part-circular pinion portion 25 which extends along the outer edge of the cage about the axis B. The teeth 26 of the pinion portion 25 mesh with a row of teeth 27 on a rack 28 which is mounted on the connection 17 for movement therewith along the track by means of a spring 29 which biases the rack into engagement with a side wall 30 of the track 12 opposite the slot 16. The surface of the rack adjacent the side wall 30 of the track, which lies on the axis of rotation A of the ball roller 20 is cut away at 31, 32 to reveal a ridge 33 and an abutment member 34 which is shaped to conform to the configuration of the aperture 19 in the end region of the track 12. An end stop 36 is formed adjacent the row of teeth 27 at the end of the rack 29 opposite the abutment 34, the end stop being engagable with the cage 113. The opposite end of the support arm 10 carries a boss 37 which is connected to a bracket 38 mounted on the door 5. The bracket 38 and the boss 37 permit relative pivotal movement through 900 about a vertical axis between the positions indicated in Figures 3 and 6. Stop surfaces on theboss 37 and the bracket 38 prevent relative rotation beyond this range of movement When the door is fully open, (Figure 3) the support arm 10 extends outwardly from the track 12 so that the axis of rotation A of the ball roller 20 lies perpendicularly to the longitudinal direction 20 of the track 12, and the rack 28 is held by the springlwith the abutment member 34 and the ridge 33 in engagement with the side wall 30 of the track. In this position, the toothed surface of the rack is inclined to the side wall 30. Since the connection 17 cannot move laterally in the track 12, the pinion portion 26 cannot roll along the rack 28. evertheless the ball roller 20 is free to roll along the track between the channel sections 21, 21' so that the door 5 can move parallel to the side of the vehicle body. When the connection 17 reaches the end region of the track, as illustrated in Figure 4, the abutment 34 on the rack engages the in-turned flange 15 on the track 12 thus preventing further movement of the rack 28 along the track 12. The rack 28 then rocks about the ridge 33 so that the abutment enters the aperture adjacent the flange. In this position, (illustrated in Figure 4) the surface of the rack carrying the teeth 27 lies parallel to the side wall 30 of the track 12, and the rack 28 no longer prevents the pinion portion 26 from travelling along the rack. Since the ball roller 20 has a spherical surface, it is free to rotate about the axis B between the channel portions 21, 21' of the track 12 thus allowing the arm 10 to effect a rolling movement along the track 12 in the common plane of the track 12 and the arm 10 as illustrated in Figures 4 to 6. The door 5 thus completes its movement in the direction parallel to the plane of the aperture and is moved into the aperture 3 to lie with its furface flush with the body of the vehicle, as shown in Figure 6. when the door 5 is opened, a force is applied to the door 5 in the longitudinal direction of the track 12. This force will be applied to the connection 17 through the support arm 10. As best seen in Figure 6, when the door 5 is closed, the arm 10 is positioned diametrically opposite the point at which the pinion portion 26 is engaged with the rack 29. The loiftent exerted on the connector about the axis B is therefore a maximum so that the opening force on the door 5 inclediately rotates the connector 17 about the axis B, causing the pinion 26 to travel along tile rack 29. The connector 17 therefore rolls along the track towards the position illustrated in Figure 4. The el#agement of the abutment 34 in the aperture 15 prevents the rack 29 from sliding along the track during this movement of the connector 17. When the cage 28 engages the end stop 36 on the rack, the rack rocks about the ridge 33 so that the abutment 34 disengages from theeperture 19. Further pivotal movement of the arm is prevented by the engaging stop surfaces on the boss 37 on the outer end of the arm 10 and the bracket 38 to which it is now connected. The axis of rotation of the ball roller 20 is/aligned at right angles to the longitudinal direction of the track 12 that the roller 20 can roll along the track with the arm 10 projecting laterally therefrom. In the embodiment of the invention illustrated in Figure 8, the will roller 20 is provided with a circumferential groove 40 extending in a plane perpendicular to the axis of rotation of the ball roller 20 relative to the cage 18*$hue roller 20 is received between two longitudinaly extending ridges 42, 42t in the track 12 which engage in the circumferential groove 40 to prevent rotation of the connection 17 about an axis B perpendicular to the common plane of the track 12 and arm 10 when the connection is displaced from the end region of the track. In the end region 12' of the track, the ball roller is received in semi-circular track sections 45, 46 which permit the roller to rotate about the axis 3. The end region 12' of the track also carried a rack 48 which is permamently secured therein. As the ball roller enters the end region of the track, a pinion portion 25 of the cage 18 in which the roller 20 is mounted engages the rack 28 and effects rotation of the arm 10 about the axis B as the connection 17 moves toaçards the end of the track 12, as illustrated by the arrow 49. and In the embodiment illustrated in Figures 9, 19/ 11 the ball roller 20 is mounted for rotation about a stub shaft 50 formed on the end of the arm 10 the ball roller 20 includes two oircumferential grooves 52 which lie in parallel plane perpendicular to the axis of rotation of the roller 20. As best seen in Figure 10, the track includes longitudinally extending ridges 54 which engage with the grooves 52 in the roller 20. The ridges 54 terminate at the end region 12' of the track (see Figure 11) where the track 12 includes two semi-circular channel sections 56, 8 within which the ball roller 20 is free to rotate about an axis 3 perpendicular to the common plane of the arm 10 and track 12. A rack 60 is secured to the side wall of the track within the end region 12' of the track and has teeth 61, which are shaped to engage with the circumferential grooves 52 in the ball roller thus causing the roller 20 to rotate about the axis 3 as it travels along the end region 12' of the track. The connection 17 therefore rolls along the rack in the end region 12' of the track so that the arm 10 swings the door 5 into the aperture 3 generally in the direction of the arrow 70 to lie flush with the surrounding walls 1.

Claims: CLAD6S. 1. A track assembly for a sliding closure member comprising a track extending in a longitudinal direction, a support arm mounted at one end in the track for travelling movement alongthstrackby a connection which retains the arm generally perpendicular to the track during part of the trairelling movement and permits rotation of the arm about an axis perpendicular to the common plane of the track and arm in one end region of the track, characterised in that the connection comprises a ball roller mounted on the arm for rolling movement along the track when the arm is generally perpendicular to the track and permitting rotation of the connection about the axis perpendicular to the common plane of the arm and the track, and means for engaging the connection to prevent such rotation when the connection is not positioned in the end region of the track. 2. A track assembly according to claim 1 further characterised by means engagable with the connection when the arm is in the end region of the track for effecting a rolling movement of the arm along the track in the said common plane. 3. A track assembly according to claim 2 wherein the means for effecting the rolling movement of the arm comprises a rack which is fixed relative to the track at least when the connection is in the end region of the track, the rack being engagable with a pinion portion on the connection. 4. A track assembly according to claim 3 wherein the pinion portion is defined by circumferential grooves in the ball roller. 5. A track assembly according to claim 3 wherein the pinion portion is formed on a cage in which the ball roller is rotatably mounted. 6. A track assembly according to claim 5 further characterised in that the rack is mounted on the connection for movement therewith along the track1 means being provided for retaining the rack in a fixed position relative to the track when the rack is in the end region of the track. 7. A track assembly according to claim 6 wherein the rack is mounted for locking movement relative to the track and rotation of the connect:ion about the axis perpendicular to the common plane of the track arbi n rinccs the rack between locking and releasing positions in which the rack prevents and allow respectively the rolling movement of tile and a;i.the rack is prevented from enterir# the releasing position engagement with a wall portion of the track when the connection is not positioned in the end region of the track. 8. I track assembly according to claim 6 wherein the rack carries an abutment which engages the wall portion of the track when the connection is not positioned in the end region of the track to retain the rack in the loosing position, and which enters a recess in the track when the connection is in the end region of the track as the rack moves into its releasing position. 9. A track assembly according to any one of claims 3 to 9 wherein the pinion portion is positioned such that it is in engagement with the rack at a point diametrically opposite the arm relative to the axis perpendicular to the common plane of mowent of the arm and the track when the arm lies parallel to the track in the end region. 10. A track assembly according to any one of claims 1 to 5 wherein the ball roller includes a circumferential groove which engages with a longitudinally extending ridge in the track which prevents the connection from rotating about the axis of perpendicular to the common plane of the arm and the track except when the connection is in the end region of the track. 11. A track assembly substantially as hereinbefore described with reference to and as shown in the accompanying drawings. 12. A sliding closure mechanism comprising a frame defining an aperture, and a closure member mounted for sliding movement into and out of the aperture, the closure being connected to the frame by two or more slidable connections at least one of which comprises a track assembly in accordance with aty one of claims 1 to 11. 13. A mechanism according to claim 12 wherein the closure is connected to the frame by means of three track assemblies according to iny one of claims 1 to 11. 14. A mechanism according to claim 12 or 13 wherein the tr#ok of at least one of the track assemblies according to an"v one of claims 1 to 11 is mounted on the door, the suppott arm being pivot ably connected to the frame. 15. A eliding closure mechanism substantially as nereinbefore described Tilth reference to the dra-tvings.

Inventors: CRUNDALL ALLEN, DENIS LYN
Applicants: FORD FRANCE SOCIETE ANONYME, FORD MOTOR COMPANY LIMITED, FORD-WERKE AKTIENGESELLSCHAFT
Application year: 1979
Main classification: E05D15
IPC codes: B60J5, E05D15