FIELD OF THE INVENTION
[0001] The invention relates to a blind apparatus and, in particular to a corner junction
assembly for use in connecting two adjacent lengths of blind track.
BACKGROUND OF THE INVENTION
[0002] Vertical slat blinds are well known and comprise a track having a plurality of blind
travellers movable therealong. Vertical blind slats are suspended from the travellers.
The travellers can be drawn to and fro along the track, and the individual blind slats
can be rotated so as to open or close the blinds.
[0003] Traveller operating or control means extend along the track and hang downwardly from
one end of the track.
[0004] The installation of two or more lengths of blind track, which meet at a corner, presents
certain problems, particularly in the arrangements for the traveller control means.
[0005] One form of arrangement for such a corner junction assembly is described in U.S.
Letters Patent 4,653,564, dated March 31, 1987 - Inventor Norbert Marocco, entitled
"Track for Blinds."
[0006] Using the system disclosed in the aforesaid patent, it is possible to joint the two
tracks at a corner and to provide for the traveller control means to extend around
the corner. In this way, the traveller control means, that is to say both the traveller
moving means and also the blind slat rotation means, can be located at one end of
one length of the track, and all of the blind travellers in both lengths of track
can be operated simultaneously.
[0007] The system disclosed in the aforesaid patent has proved to be highly satisfactory
in use, and has achieved considerable commercial success.
[0008] However, certain problems have arisen as a result of the experience of using the
aforesaid system. In particular, it is desirable to have a corner junction assembly
which is capable of hinging or swinging, and then being set in a desired angle, so
as to fit a particular window, or other installation.
[0009] One form of corner junction means is shown in the aforesaid patent and has proved
to be satisfactory. However, it incorporates several different components which must
be assembled together during assembly of the blind and this may, in practice, require
a certain amount of skill. In addition, the practice for assembling such blinds is
to, first of all, assemble the lengths of track in the factory, and set them at the
correct angle. The traveller operating means are then adjusted as to length so as
to extend around the correct arc at each corner.
[0010] Once all of this has been done, the blind installation is then disassembled and shipped
but then must be reassembled on the customer's premises.
[0011] In order to do this satisfactorily it is desirable to have a corner junction assembly
which can be preset at a predetermined angle, so that when disassembled and then reassembled,
it will go together in the correct fashion.
[0012] It is also desirable that the corner junction assembly shall be as short as possible.
In blinds of this type, the blind slats are moved along the separate lengths of track
in separate groups, although they are in fact moved simultaneously. When drawn fully
to one side, the blind slats will hang, in groups, at the ends of their respective
lengths of track. In order to avoid obstructing the ends of the tracks, it is thus
desirable that the corner junction assembly at the ends of the tracks shall be as
short as possible.
SUMMARY OF THE INVENTION
[0013] With a view to overcoming the various problems listed above, the invention comprises
a corner junction assembly for use in association with two adjacent blind tracks,
such tracks each being adapted to carry slat-carrying travellers and each having at
least one movable traveller control means, the corner junction assembly comprising
at least one bearing ring means; at least one bearing hub means making a captive frictional
fit within the bearing ring means to permit relative rotation thereof; track engagement
means connected to respective ones of the bearing ring means and the bearing hub means
for engagement with adjacent ends of respective ones of the tracks; and at least one
movement transmission means adapted to be coupled to and to transmit movement from
the traveller control means in one of the blind tracks to the traveller control means
in the other of the blind tracks.
[0014] Usefully, a corner junction assembly in accordance with this invention comprises
upper and lower bearing ring means and upper and lower bearing hub means, the upper
bearing hub means making a captive frictional fit within the upper bearing ring means
and the lower bearing hub means making a captive frictional fit within the lower bearing
ring means, and the upper and lower bearing ring means being spaced apart.
[0015] Such a corner junction assembly is usefully provided with an opening in one of the
upper and lower bearing hub means and a removable closure means is provided for closing
the opening.
[0016] In accordance with a particularly preferred feature of this invention, a corner junction
assembly in accordance therewith includes a downwardly dependent arcuate cup member
formed integrally with the upper bearing hub means, and a bearing surface of corresponding
shape is formed on the upper bearing ring means to guidingly engage the exterior of
the cup member.
[0017] Such a cup member is usefully formed with a plurality of fracture lines parallel
to one another at spaced intervals therearound, whereby portions of the cup member
may be broken away during installation of the corner junction assembly with the blind
tracks to accommodate different angular positions of those blind tracks.
[0018] The bearing hub means of a corner junction assembly in accordance with this invention
is usefully formed with a locking ring making a captive pressure fit within the bearing
ring means.
[0019] In one embodiment of a corner junction assembly according to the invention, the movement
transmission means comprises at least one length of control cord integrally formed
with control cords in each of the tracks and constituting the aforementioned traveller
control means, as well as at least one pulley for guiding such length of the control
cord. In one particular embodiment, such pulleys are mounted externally on the corner
junction assembly.
[0020] Another embodiment of a corner junction assembly according to the invention is intended
for use with blind tracks in which the traveller control means are rotationally mounted
and in such an embodiment such movement transmission means is adapted to transmit
rotational movement between the traveller control means of the two blind tracks. Such
a rotatable mounted movement transmission means can comprise a flexible coupling and
at least one bearing means supporting the flexible coupling.
[0021] Usefully, such a flexible coupling is adapted to be connected to the traveller control
means for conjoint rotation therewith but in such a manner that axial movement of
the flexible coupling relative to at least one of the traveller control means is possible
to accommodate different angular positions of the blind tracks.
[0022] In another embodiment, such rotatably mounted movement transmission means comprises
interengaged gear means adapted to be secured to ends of the traveller control means
of the blind tracks for conjoint rotation therewith. In one embodiment, such gear
means are adapted to be secured to the ends of the traveller control means for conjoint
rotation therewith while permitting axial movement of the gears means relative to
at least one of the traveller control means to accommodate different angular positions
of the tracks.
[0023] Spring means are usefully provided to maintain such gear means in engagement with
each other regardless of the relative angular positions of the tracks. If, however,
such gear means are disposed for rotational movement through a rotational axial position
of the corner junction assembly, then there is no need for relative axial movement
of the gear means and the traveller control means during movement of the blind tracks
into different angular positions.
[0024] The various features of novelty which characterize the invention are pointed out
with more particularity in the claims annexed to and forming a part of this disclosure.
For a better understanding of the invention, its operating advantages and specific
objects attained by its use, reference should be had to the accompanying drawings
and descriptive matter in which there are illustrated and described preferred embodiments
of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The invention will now be described merely by way of illustration with reference
to the accompanying drawings in which:
Figure 1 is a general perspective illustration of one embodiment of a blind installation
or apparatus in accordance with this invention, and shown as extending along three
walls which meet at two corners;
Figure 2 is a bottom plan view, looking upwardly of one embodiment of a corner junction
assembly as used in the blind assembly as shown in Figure 1 and with certain parts
omitted to reveal its internal construction;
Figure 3 is a sectional view when taken as indicated by the arrows 3-3 of Figure 2;
Figure 4 is an exploded perspective illustration of the corner junction assembly shown
in Figures 1 to 3;
Figure 5 is a cut-away perspective view of the same corner junction assembly with
certain parts omitted;
Figure 6 is a schematic perspective view of one embodiment of a traveller and traveller
control means used in the blind installation shown in the preceding figures;
Figure 7 is a schematic perspective view of a second embodiment of a traveller and
control means which can be used in a blind installation in accordance with this invention;
Figure 8 is a perspective exploded illustration of a flexible coupling for use in
a corner junction assembly in accordance with this invention;
Figure 9 is a perspective illustration of an alternative form of coupling for use
in this invention;
Figure 10 is an exploded sectional view when taken as indicated by the arrows 10-10
of Figure 9;
Figure 11 is a rear perspective illustration of an alternative embodiment of a corner
junction assembly in accordance with this invention; and
Figure 12 is a sectional view through another embodiment of a corner junction assembly
in accordance with this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Referring first of all to Figure 1, it will be seen that the invention is illustrated
therein as a blind installation mounted in a situation in which there are three wall
surfaces indicated generally as W, meeting at two corners indicated generally as C.
[0027] Typically, this represents a bay window installation. However, blinds may be used
in bay windows, or may be used to cover other openings or other surfaces, and the
invention is not to be taken as exclusively limited to use in association with bay
windows or, in fact, windows of an kind.
[0028] A plurality, in this case, three, lengths of blind tracks generally indicated at
10, are shown mounted on the walls W, with the three lengths of track 10 meeting at
the two corners C.
[0029] From the tracks 10 a plurality of slats 12 hang downwardly from the travellers 14.
[0030] Traveller control means are provided which, in this embodiment of the invention,
are indicated as the control or pull cord 16 and the control rod 18. The cord 16 hangs
downwardly at one end of one of the tracks 10 and is operative to move the slats 12
along the tracks 10. The control rod 18 is rotatable by movement of a control chain
19 to adjust the angular position of the slats 12 relative to the tracks 10. The hanging
portion of the cord 16 and the control chain 19 are shown in a horizontal position
in Figure 2 to clarify their functions.
[0031] It will be appreciated that the showing of a control cord 16 and a control rod 18
are merely illustrated as the traveller control means in general. Various different
designs of traveller control means are possible and the invention is not intended
to be restricted to any particular form of traveller control means.
[0032] The tracks 10 and slats 12 may be of entirely conventional construction, such as
are well known in the art and are made by a number of different manufacturers and
are not, therefore, described in any detail, for the sake of clarity.
[0033] As shown generally in Figure 1, the three lengths of blind track 10 are joined at
the two corners C by means of corner junction assemblies in accordance with this invention
and as indicated generally at 20.
[0034] Referring now to Figure 4, the corner junction assembly 20 in accordance with the
invention will be seen to comprise five separate moulded components, namely an upper
bearing ring member or means 22, an upper bearing hub member or means 24, a lower
bearing ring member or means 26, a lower bearing hub member or means 28, and a closure
means or plate 30, provided for the sake of appearance.
[0035] Upper bearing ring member 22 comprises a generally annular bearing means 32, and
an upstanding annular wall 34, forming an L-shaped structure in section.
[0036] Along one side of the junction between the bearing means 32 and the wall 34, there
is formed a downwardly dependent end plate 36, with a guidance opening or bearing
38 formed therethrough.
[0037] A pair of generally rectangular track engagement means or mounting block members
40 are also integrally formed with the upper bearing ring member 22 and extend more
or less normal thereto on either side of the plate 36 to define openings 41 on either
side thereof.
[0038] A bearing surface or arcuate guidance cuff 42 is formed integrally with one of block
members 40 and the annular bearing means 32. A guidance pulley 43 is mounted on a
guidance wedge portion 44 formed integrally with the other of blocks 40. A screw receiving
recess 45 is formed in cuff 42.
[0039] The upper bearing hub member 24 comprises an annular bearing hub 46, having an upper
free edge terminating in a locking ring 48. Hub 46 and ring 48 are intended to make
a snap fit through the bearing means 32, and to be rotatable therein.
[0040] A flat disc-like plate 50 is formed integrally with the lower edge of the bearing
hub 46. A generally partially cylindrically shaped downwardly dependent wall or cup
member 52 extends downwardly from the perimeter of plate 50, thus forming what may
be called an inverted cup-shaped structure.
[0041] Fracture or break lines 54 (shown in Figure 4 but omitted from Figure 3) are provided
in the wall 52 for a purpose yet to be described.
[0042] A downwardly-dependent planar flange 58, having a guidance opening or bearing means
60, is provided on plate 50 and has openings 61 on both sides for a reason yet to
be described.
[0043] Two generally wedge-shaped block portions 64 and 66 are formed on the exterior of
the generally cylindrical wall 52. A screw-receiving recess 68 is usefully formed
in the block portion 64 for a reason yet to be described.
[0044] A guidance pulley 69 is mounted on block portion 66.
[0045] Track engagement means or mounting block members 70 are formed on respective blocks
64 and 66, for engagement with one of the blind tracks 10.
[0046] The lower bearing ring member 26 comprises an annular bearing ring 72, with an arcuate
guidance cuff 74 formed therearound. An attachment flange 76 extends from the guidance
cuff 74, and is usefull provided with a screw hole opening 78.
[0047] A screw 80 passes through opening 78 and is received in screw receiving recess 45
in cuff 42 of upper bearing ring member 22.
[0048] The lower bearing hub member 28 comprises a bearing hub ring 82, having at its upper
free edge a locking ring 84. Rings 82 and 84 makes a snap fit within bearing ring
72 of bearing ring member 26, and are rotatable relative to one another. A generally
outwardly-extending bearing flange 86 is formed around the lower edge of hub ring
82, and extends outwardly substantially normal thereto defining a generally L-shape
in section. A downwardly-dependent annular wall 88 extends around the exterior of
the flange 86.
[0049] A mounting flange 90 is provided along one edge of flange 86, and has a screw receiving
opening 92 for screw 94.
[0050] Screw 94 is intended to be received in recess 68 in block portion 64 of upper bearing
hub member 24.
[0051] The flange 86 also defines a central opening 96 therethrough. In order to close this
opening the closure plate 30 comprises a fastening sleeve 98, with a locking ring
100 adapted to make a snap fit within opening 96. A generally flat disc-like plate
102 is moulded to the bottom edge of the sleeve 98.
[0052] Screws indicated as 104 may be fastened through suitable holes drilled in the end
portions of tracks 10, and such screws will then be received in screw recesses (not
shown) formed in the respective block members 40 and 70.
[0053] In this way, the corner junction assembly can be connected between two adjacent lengths
of track 10 as shown in Figure 5, and the two lengths of track are then rendered swingable
relative to one another, within the limits of the arc defined by the construction
of the corner junction member.
[0054] As is also shown in Figure 3, the traveller control means, namely the control cord
16 and the control rod 18, extend through respective openings in the wall or cup member
52, and extend around the arc of the corner. Pull cords 16 are guided around the corner,
by pulleys 43 and 69, and by a further pulley 105 mounted in the interior of the wall
52, typically by being fastened to the underside of the plate 50.
[0055] The control cord 16 runs through the spaces on opposite sides of plate 36 and flange
58 and there constitutes a movement transmission means. Portions of wall 52 may be
broken away, along lines 54, to allow free passage of the pull cords through the corner
assembly 20.
[0056] Traveller engagement means such as buttons 107 are provided on cords 16, as described
in U.S Patent 4,653,564, and require no further description.
[0057] The control rods 18 may be coupled by means of a movement transmission means or flexible
coupling 106, described below.
[0058] A typical traveller 14 used in this type of blind is shown in Figure 6.
[0059] Alternatively, however, the invention is equally applicable to blinds in which a
modified form of traveller 108, as shown in Figure 7, is used. In this form of traveller
a control rod 110 is provided, for a similar purpose to the control rod 18 in the
traveller 14; that is to say, the control rod 110 rotates the slats, as does the control
rod 18 in the embodiment of Figure 6.
[0060] However, the traveller 108 differs from the traveller 14 in that the pull cord 16
is replaced by a continuous screw rod 112. The interior of the traveller is so constructed
that by the rotation of the screw rod 112 the travellers are caused to move to and
fro along the track.
[0061] The details of such travellers are well known to persons skilled in the art and require
no further description.
[0062] In this form of the invention, two flexible couplings 114 and 116 would be provided
in each corner: one joining two control rods 110 and, one joining two screw rods 112.
The two flexible couplings would be similar to the single flexible coupling 106 shown
in Figures 2, 3 and 8.
[0063] The flexible coupling 106 is shown in more detail in Figure 8, from which it will
be seen to comprise a length of helical wound spring wire 120, the two ends of which
are embedded in identical coupling members or drive hubs 122 which are relatively
elongated and which fit, with a certain degree of clearance, within openings or bearing
means 38 and 60 of the corner ring member 22 and the bearing hub member 24 respectively
(see Figure 3).
[0064] Collars 124 are formed on hubs 122 and act as thrust plates, so as to ensure that
the hubs 122 remain in the correct position, and rotate freely.
[0065] The free ends of hubs 122 are provided with splined recesses 126, to receive adjacent
ends of the two control rods 18.
[0066] The spring portion 120 is flexible (as shown in phantom) and will normally be straight,
and can be flexed to fit around the desired angle to which the corner junction assembly
20 is set.
[0067] An alternative form of movement transmission means is shown in Figures 9 and 10.
[0068] As shown in Figure 9, a movement transmission means indicated generally as 130 comprises
two crown gear wheels 132a, 132b each having identical teeth 134 formed thereon. The
teeth 134 are formed essentially as pins or rods, with reinforcing web portions 136
(Figure 10) extending therefrom at an angle. Both crown wheels 132 are formed with
a splined recess 138 to receive the end of the respective control rod 18. Within each
recess 138, there is provided a spring 140.
[0069] The effect of the two springs 140 is to urge the two gear wheels 132a and 132b into
engagement with one another at the various different angles to which the corner assembly
may be set.
[0070] In the embodiment of Figures 1, 2 and 3, the track 10 is shown in which the travellers
and all of the moving parts are contained inside the tracks.
[0071] However, there are certain manufacturers who manufacture tracks in which some of
the controls are arranged exteriorly of the track.
[0072] One such form of track is shown in Figure 11 as 150.
[0073] In this case, the travellers, (not shown) are located within the track in essentially
the same way as is shown in Figure 2. In addition, control rods (not shown) are arranged
within the tracks.
[0074] In the form of track shown in Figure 11, however, the manufacturer has chosen to
provide flexible control elements 152 which are located externally on the concealed
or rearward side of the tracks 150. The control elements 152 are attached to traveller
brackets 154 connecting with the lead travellers in each group.
[0075] The traveller brackets 154 extend through slots 156.
[0076] In the case of this form of track, the present invention provides a modified form
of corner assembly indicated generally as 160.
[0077] The corner junction assembly 160 is made substantially as shown in Figures 3 and
4, but without the interior pulleys for guiding the flexible elements.
[0078] Instead, exterior pulley mounting brackets 162 are provided on the rearward or concealed
side of the corner 160, having pulleys 164 mounted thereon.
[0079] Two pulleys are provided for each of the flexible elements making a total of four
in all.
[0080] The two pulley mounting brackets 162 are attached to the corner assembly 160 in such
a way that when the corner assembly is swung to a desired angular position, the pulley
mounting brackets 162 will also swing apart from one another. Thus the pulleys 164
will remain in engagement with the flexible elements at all times.
[0081] Reference will finally be made to Figure 12 in which there is indicated generally
at 170 a corner junction assembly for use with tracks 172 housing control rods 110
for changing the rotational position of the slats and screw rods 112 for moving the
slats along the tracks.
[0082] Rotational movement is transferred in the corner junction assembly 170 between the
control rods 110 in essentially the same manner as already described with reference
to the embodiment shown in Figures 9 and 10.
[0083] In the embodiment shown in Figure 12, the control rods 110 pass through inner bearing
members 174 having splined axial bores 176 receiving the control rods 110 for co-rotation
therewith. The inner bearing members 174 are rotatably received within bores 178 formed
in fixed mounting sleeves 180. The ends of the control rods 110 are secured in openings
in crown gear wheels 184a and 184b having teeth 185 by set screws 186. It has been
found that, by disposing the drive transfer members so that the teeth 134 rotate through
a position which lies essentially on the rotational axis 187 of the corner junction
assembly 170, the need for relative axial movement of the control rods 110 and the
crown gear wheels 184a and 184b is eliminated. Consequently, in this particular embodiment,
there is no need for the compression springs 140 as shown in Figure 10.
[0084] Similarly, rotational movement is transferred in the corner junction assembly 170
between the screw rods 112 in essentially the same manner as already described with
reference to Figure 8 using a flexible coupling indicated generally at 188. From Figure
12, it will be seen that the flexible coupling 188 comprises a length of helically
wound spring wire 190, the ends of which are anchored in couplings 192 which are,
in turn, mounted for limited axial movement in bores in drove hubs 194 The couplings
192 and the bores in the drive hubs 194 have corresponding non-circular cross-sectional
shapes, for example, hexagonal, to ensure conjoint rotation of the couplings 192 and
the drive hubs 194.
[0085] The drive hubs 194 are provided with axially spaced apart annular grooves 195 and
196 which receive corresponding ribs 198 provided on the corner junction assembly
170 to permit free rotation of the hubs 194.
[0086] In adjusting the angular position of the tracks 172, the couplings 192 move within
the drive hubs 194. In the event that it is desired to position the tracks 172 at
a relatively small angle, the drive hubs can be moved within the corner junction assembly
170 so that the ribs 198 are disposed within the recesses 195 rather than the recesses
196 as actually shown in Figure 12. This is effective to separate the drive hubs 194
a sufficient distance to permit the required separation of the couplings 192.
[0087] The drive hubs 194 are secured to the screw rods 112 by set screws 199.
[0088] The foregoing is a description of a preferred embodiment of the invention which is
given here by way of example only. The invention is not to be taken as limited to
any of the specific features as described, but comprehends all such variations thereof
as come within the scope of the appended claims.
1. A corner junction assembly (20) for use in association with two adjacent blind
tracks (10), said tracks (10) each being adapted to carry slat-carrying travellers
(14) and each having at least one movable traveller control means (16, 18), said corner
junction assembly (20) comprising:
at least one bearing ring means (22);
at least one bearing hub means (24) making a captive frictional fit within said bearing
ring means (22) to permit relative rotation thereof;
track engagement means (40, 70) connected to respective ones of said bearing ring
means (22) and said bearing hub means (24) for engagement with adjacent ends of respective
ones of said tracks (10); and
at least one movement transmission means (16, 106) adapted to be coupled to and to
transmit movement from a said traveller control means (16, 18) in one said blind track
(10) to said traveller control means (16, 18) in the other said blind track (10).
2. A corner junction assembly (20) as claimed in Claim 1 and which comprises upper
and lower said bearing ring means (22, 26) and upper and lower said bearing hub means
(24, 28), said upper bearing hub means (24) making a captive frictional fit within
said upper bearing ring means (22) and said lower bearing hub means (28) making a
captive frictional fit within said lower bearing ring means (26), and said upper and
lower bearing ring means (22, 26) being spaced apart.
3. A corner junction assembly (20) as claimed in Claim 2 and including an opening
(96) in one of said upper and lower bearing hub means (24, 28); and
removable closure means (30) closing said opening (96).
4. A corner junction assembly (20) as claimed in Claim 2 and including a downwardly
dependent arcuate cup member (52) formed integrally with said upper bearing hub means
(24), and a bearing surface (42) of corresponding shape, formed on said upper bearing
ring means (22) and guidingly engaging the exterior of said cup member (52).
5. A corner junction assembly (20) as claimed in Claim 4 wherein said cup member (52)
is formed with a plurality of fracture lines (54) parallel to one another at spaced
intervals therearound, whereby portions of said cup member (52) may be broken away
during installation of said corner junction assembly (20) with said blind tracks (10)
to accommodate different angular positions of said blind tracks (10).
6. A corner junction assembly (20) as claimed in Claim 1 wherein said bearing hub
means (24) is formed with a locking ring (48) making a captive pressure fit within
said bearing ring means (22).
7. A corner junction assembly (20) as claimed in Claim 1 and in which said movement
transmission means (16) comprises at least one length of control cord (16) integrally
formed with control cords (16) in each of said tracks (10) and constituting said traveller
control means (16), and at least one pulley (43, 69, 105) for guiding said length
of said control cord (16).
8. A corner junction assembly (160) as claimed in Claim 7 wherein said at least one
pulley (164) is located externally of said bearing ring means (22) and said bearing
hub means (24).
9. A corner junction assembly (20) as claimed in Claim 1 for use with blind tracks
(10) in which said traveller control means (18) are rotationally mounted and in which
said movement transmission means (106) is adapted to transmit rotational movement
between said traveller control means (18) of said two blind tracks (10).
10. A corner junction assembly (20) as claimed in Claim 9, in which said movement
transmission means comprises a flexible coupling (106) and which comprises at least
one bearing means (38) supporting said flexible coupling (106).
11. A corner junction assembly (170) as claimed in Claim 10 and in which said flexible
coupling (188) is adapted to be connected to said traveller control means (112) for
conjoint rotation therewith but in such a manner that axial movement of said flexible
coupling (188) relative to at least one said traveller control means (112) is possible
to accommodate different angular positions of said blind tracks (172).
12. A corner junction assembly (20) as claimed in Claim 9 and in which said movement
transmission means comprises interengaged gear means (132) adapted to be secured to
ends of said traveller control means (18) of said blind tracks (10) for conjoint rotation
therewith.
13. A corner junction assembly (20) as claimed in Claim 12 and in which said gear
means (132) are adapted to be secured to said ends of said traveller control means
(18) for conjoint rotation therewith while permitting axial movement of said gears
means (132) relative to at least one of said traveller control means (18) to accommodate
different angular positions of said tracks (10).
14. A corner junction assembly (20) as claimed in Claim 13 and in which each at least
one said gear means (132) comprises spring means (140) adapted to maintain said gear
means (132) in engagement with each other regardless of the relative angular positions
of said tracks (10).
15. A corner junction assembly (170) as claimed in Claim 12 and in which said gear
means (184) are disposed for rotational movement through a rotational axial position
(187) of said corner junction assembly (170) to eliminate the need for relative axial
movement of said gear means (184) and said traveller control means (110) during movement
of said blind tracks (172) into different angular positions.