Anti-float system for operable partitions

An anti-float system for operable partitions in a movable wall system. The anti-float system includes first and second camming assemblies, each including a trolley camming surface, cooperatively positioned along the operable partition track. Preferably both of the trolley camming surfaces are spring biased to camming positions where they define a passageway through which a portion of the trolley passes when the trolley moves along the track. The passageway is narrower than the width of the trolley portion. When the trolley portion enters the passageway while traveling in the wall extending direction, the trolley portion engages the trolley camming surfaces and forces the surfaces outward from their camming positions against a resistance provided by the biasing springs in order for the trolley to pass. The camming assemblies are also movable from a camming alignment to a retracted alignment when the trolley portion travels in the wall stacking direction through the passageway.

BACKGROUND OF THE INVENTION 
This invention pertains to operable partitions movable to partition large 
rooms into smaller rooms, and, in particular, to an anti-float system for 
preventing operable partitions from floating out from their stacked 
arrangement when they are moved between their open, stacked position and 
their closed, wall forming position. 
Operable partitions, also known as movable wall panel systems, find useful 
application in a variety of venues, such as classrooms, offices, 
convention centers and hospitals. In these venues, the operable partitions 
can be utilized to efficiently compartmentalize interior space into a 
multitude of separate, smaller rooms. One type of movable wall panel 
system is a continuously-hinged system, in which each operable partition 
is typically hinged to its adjacent partitions. Continuously-hinged wall 
panel systems are frequently electrically driven between a stacked 
position and an extended, wall forming position. When arranged in a proper 
center stacked position, the operable partitions are folded over one 
another accordion style with each panel or partition being oriented 
generally transverse to the overhead track. 
One shortcoming of continuously-hinged operable partitions is known as 
floating and is manifested during the movement of the operable partitions. 
During partition movement, stacked operable partitions have a tendency to 
float out, i.e. move along the overhead track away from the location at 
which they are arranged when properly stacked. For instance, when 
continuously-hinged operable partitions are extended to form a wall, the 
leading partition, which is connected to an electric motor via a chain, is 
pulled from its transverse position at the end of a stacked set of 
partitions and begins to straighten out. Straightening of the leading 
partition is normally assisted by guide rails flanking the overhead track 
which engage the partitions. As the leading partition is pulled off, the 
remaining stacked partitions, still in a substantially stacked arrangement 
transverse to the track, often begin to float out in the wall extending 
direction. This floating is undesirable as these floating stacked 
partitions can jam at the guide rails and hinder further wall extension. 
Floating may also be problematic when continuously-hinged operable 
partitions are stacked. During the stacking process, the trailing 
partitions which first reach the stacking area are manipulated to break 
and stack. If these stacked partitions float out, they may interfere with 
the stacking of subsequent partitions and frustrate the stacking process. 
In addition, floating can also be a problem with non-level tracks as 
gravity may cause some partitions to float. 
An existing anti-float assembly or apparatus includes two cables, with 
loops at each end, and a high tension spring interconnecting the cables. 
The assembly spring is installed in a recess within the top edge of one 
partition, and each of the cables is guided through mounted diverters and 
connected to an adjacent partition. This assembly has several 
shortcomings. For instance, the assembly is difficult to install, must be 
carefully checked and tightened before installation, and occasionally is 
not installed for those reasons as well as because of a lack of 
comprehension by an installer of its function. The separate custom 
designed components of the assembly may also be relatively expensive. 
Furthermore, the design of the assembly requires that the cables during 
operation pass within the space normally occupied by the top sweeps, which 
extend to the room ceiling, of the partitions. The removal of a portion of 
the top sweep to accommodate the cables results in a degradation of the 
acoustical performance of the partition in the field. Thus, it is 
desirable to provide an anti-float apparatus which prevents floating of 
the operable partitions without some of these disadvantages. 
SUMMARY OF THE INVENTION 
In one form thereof, the present invention provides an anti-float apparatus 
for use with a track and a trolley coupled to an operable partition. The 
anti-float apparatus includes a first camming assembly positioned along 
the track. The first camming assembly includes a first trolley camming 
surface and means for biasing the first trolley camming surface inward to 
a camming position. The anti-float apparatus also includes a second 
camming assembly, positioned along the track to cooperate with the first 
camming assembly, which has a second trolley camming surface. The first 
trolley camming surface, when disposed in the camming position, and the 
second trolley camming surface define a passageway therebetween. This 
passageway is positioned for passage therethrough of a portion of the 
trolley when the trolley moves along the track. The passageway is narrower 
than the width of the trolley portion. The first trolley camming surface 
is forcible outward from the camming position against a resistance 
provided by the camming surface biasing means when the trolley portion 
enters the passageway while traveling in the wall extending direction 
resulting in motion of the trolley in the wall extending direction being 
resisted. 
In another form thereof, the present invention provides an anti-float 
system for use with a track and a trolley from which is suspended an 
operable partition. The anti-float system includes a mounting bracket 
connectable to the track, a first camming assembly, and a second camming 
assembly. The first camming assembly includes a first camming arm, having 
a first trolley camming surface, coupled to the mounting bracket and 
movable relative thereto between a camming alignment and a retracted 
alignment. The first camming assembly also includes means for biasing the 
first trolley camming surface inward to a camming position. The second 
camming assembly includes a second camming arm, coupled to the mounting 
bracket, having a second trolley camming surface. The first trolley 
camming surface, when disposed in the camming position, and the second 
trolley camming surface define a passageway for a portion of the trolley 
therebetween. This passageway has a narrower width than the width of the 
trolley portion. The first trolley camming surface is forcible outward 
from the camming position against a resistance provided by the camming 
surface biasing means to thereby increase the width of the passageway and 
enable passage therethrough of the trolley portion when the trolley 
portion enters the passageway while traveling in the wall extending 
direction with a force sufficient to overcome the resistance. The 
resistance is sufficient to prevent passage therethrough of the trolley 
portion when the trolley portion is traveling in the wall extending 
direction without sufficient force. The system also includes means for 
moving the trolley portion in the wall extending direction at the force 
sufficient to overcome the resistance. The first camming arm is movable 
from the camming alignment to the retracted alignment when the trolley 
portion engages the first trolley camming surface while traveling in the 
wall stacking direction during passage through the passageway. 
In still another form thereof, the present invention provides an anti-float 
system for an operable partition including a track, a trolley coupled to 
the operable partition and movable along the track in a wall stacking 
direction and a wall extending direction, a first trolley engaging camming 
surface, means for biasing the first trolley engaging camming surface to a 
camming position, a second trolley engaging camming surface, and means for 
positioning the first trolley engaging camming surface and the second 
trolley engaging camming surface at a location along the track. The first 
trolley engaging camming surface, when disposed in the camming position, 
and the second trolley camming surface define a passageway therebetween. 
The passageway is arranged for passage therethrough of a portion of the 
trolley when the trolley moves along the track and is narrower than a 
width of the trolley portion. The first trolley camming surface is 
forcible from the camming position against a resistance provided by the 
camming surface biasing means when the trolley portion enters the 
passageway while traveling in the wall extending direction, whereby motion 
of the trolley in the wall extending direction is opposed. 
An advantage of the anti-float system of the present invention is that it 
operates without impairing the acoustical integrity of the operable 
partitions. Another advantage of the present invention is its ease of 
installation. Another advantage of the present invention is that the 
strength of the float resistance applied to the partitions is adjustable. 
Still another advantage of the present invention is its adaptability for 
use with different trolley designs.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, there is shown a diagrammatic top view of a moveable 
wall panel system, generally designated 10, which is used to form a 
temporary wall between two fixed walls 12, 14. Moveable wall panel system 
10 includes a number of continuously-hinged operable partitions 16 which 
are suspended from trolleys, generally designated 18 (See FIG. 2), guided 
within overhead track 20. As is conventional, track 20 is mounted in the 
ceiling of the room and spans walls 12, 14, and trolleys 18 are provided 
in the first or leading operable partition 16 and every other partition 16 
thereafter. Operable partitions 16 are connected to an electric motor (not 
shown) in a manner known to those of ordinary skill in the art to provide 
for automatic wall opening and closing. Operable partitions 16 can be 
moved between an open, stacked position adjacent fixed wall 12 and a 
closed, extended wall forming position directly under and along the length 
of track 20. In FIG. 1, operable partitions 16 are illustrated at an 
intermediate stage of their movement between the stacked and extended 
positions. It will be appreciated that while explained herein with 
reference to continuously-hinged operable partitions which are motor 
driven, the present invention can be advantageously utilized with wall 
systems using separate partitions and with wall systems which are manually 
pulled or otherwise moved. 
The anti-float apparatus of the present invention, generally designated 40, 
is abstractly shown in FIG. 1. Anti-float apparatus 40 is particularly 
designed to prevent partitions 16 which are arranged in their stacked 
orientation from floating out, or to the right in FIG. 1, when the movable 
wall system 10 is being extended or stacked. It is desirable both to allow 
the leading partition 16 to move without passing through and experiencing 
resistance from apparatus 40 as well as to ensure that the partitions 16 
trailing the leading partition are advantageously controlled by apparatus 
40. Consequently, anti-float apparatus 40 is preferably positioned along 
track 20 between the position occupied by the trolley 18 of the leading 
operable partition 16 and the first trolley 18 to the left in FIG. 1 of 
the leading operable partition trolley when movable wall system 10 is 
fully retracted or stacked. It will be appreciated that anti-float 
apparatus 40 also operates if installed either to the right or left of the 
preferred installation location. 
The construction of the preferred anti-float apparatus 40 and a suitable 
but not required track 20 and trolley 18 for use therewith follows with 
reference initially to FIGS. 2 and 3. Track 20 is generally C-shaped in 
vertical cross-section. Trolley 18 includes four wheels 24 which roll 
along the inside surface of track 20. Wheels 24 are journaled to a 
vertically extending flat plate 26 of a uniform thickness. Plate 26 
extends downward through channel opening 22 in track 20 and has a centered 
horizontal flange 28 perpendicularly welded to its lower edge. Horizontal 
notches 30 formed in the side edges of plate 26 are each filled with a 
roller 32 rotatably mounted on a vertical axle connected to plate 26. 
Rollers 32 provide trolley 18 with a low friction contact with the edges 
of track 20 which define channel opening 22. At the lower edge of plate 
26, head 36 of threaded trolley shaft 37 fits within aperture 34 of plate 
26 and is supported by the top of flange 28. Threaded trolley shaft 37 
extends through flange 28 and may project below a room ceiling and be 
connected to suspended partition 16 in any well known manner. 
Still referring to FIGS. 2 and 3, anti-float apparatus 40 is shown 
installed or mounted on track 20. In view of the following disclosure, it 
will be appreciated that the illustrated mounting bracket assembly is 
merely a preferred mounting technique out of the many possible 
alternatives. In particular, the camming assemblies which during operation 
engage trolley 18 and oppose or resist its motion could be positioned or 
stationed at an appropriate location along track 20 by way of a mounting 
bracket connected to the ceiling or the framework (not shown) from which 
track 20 is suspended. Alternatively, an integral formation or welded 
attachment of these camming assemblies with track 20 may be employed, 
however such an arrangement might hinder the adjustability of apparatus 40 
along track 20. 
The preferred mounting bracket, generally designated 41, includes two 
C-shaped bracket halves 42, 44 which are mirror images of one another. 
Angled coupling flanges 46, 48 have horizontal flange sections which are 
attached by weld to the upper legs of brackets halves 42, 44 respectively. 
Bolts 49, which pass through holes in vertical flange sections of flanges 
46, 48, are tightened with washers and nuts 50 to rigidly secure the 
separate bracket halves 42, 44 together. A pair of angled side flanges 56, 
58 are attached by weld to the sides of bracket halves 42, 44. The 
laterally extending flange sections of side flanges 56, 58 each include 
two threaded bores which receive removable fasteners such as screws 59 and 
washers 60. 
To longitudinally secure mounting bracket 41 at a selected point along the 
length of track 20, screws 52 inserted in threaded bores in the upper legs 
of bracket halves 42, 44 tighten down into contact with the top leg of 
track 20. When screws 52 are tightened, the lower legs of bracket halves 
42, 44 are in effect raised into frictional engagement with the lower legs 
of track 20. Screws 54 inserted in threaded bores in the sides of bracket 
halves 42, 44 further secure mounting bracket 41 to track 20. 
Adjustably connected to the partition stacking side of the laterally 
extending flange sections of side flanges 56, 58 are adjustment plates 62, 
64, which are mirror images of one another. As a result, explanation with 
reference to adjustment plate 62 in FIG. 4 has equal application to 
adjustment plate 64. Adjustment plate 62 has two slots 66 formed 
therethrough which are vertically aligned with the threaded bores which 
receive screws 59. Two projecting pivot mounting ears 68, 69 are attached 
by welding to plate 62. As shown in FIG. 3, adjustment plate 62 also 
includes a threaded bore, which receives stop screw 71, and a hole for 
attachment of one end of extension spring 73. 
Referring now to FIG. 4, a preferred camming assembly is shown in 
cross-section as taken along line 4--4 of FIG. 3, and is representative of 
both camming assemblies shown in FIG. 2. The camming assembly includes a 
camming arm 75, which is constructed from a one-inch square tube and 
laterally and horizontally extends toward the underside of track 20. Holes 
aligned in camming arm 75, pivot mounting ears 68, 69, and a bore through 
a square pivot block 80 inserted within camming arm 75 receive a spring 
pin 78 or other fastener therethrough which pivotally connects camming arm 
75 to adjustment plate 62. Within the end of camming arm 75 opposite pivot 
block 80 is a cam bearing or roller 82. The inward surface region 90 of 
roller 82 contacts plate 26 of trolley 18 during movement of trolley 18 
during wall movement as described further below. Roller 82 is rotatably 
supported on spring pin 83, which securely fits within holes provided in a 
pair of cam mounts 85 above and below roller 82. Opposing ends of spring 
pin 83 project beyond the surfaces of cam mounts 85 and extend into guide 
slots 86 (See FIG. 5) on the top and bottom faces of camming arm 75. 
Compression spring 88 is loaded within camming arm 75 and acts against the 
outward surface of cam mounts 85 and the inward surface of pivot block 80. 
While cam mounts 85 are preferably provided to prevent frictional contact 
between roller 82 and compression spring 88, and pivot block 80 is 
provided such that compression spring 88 does not directly frictionally 
contact pivot spring pin 78, both parts are not essential for a proper 
operation of the invention. In addition, while the biasing of rollers 82 
is with a compression spring and internal to camming arms 75, and camming 
arm 75 and the adjustment plates do not laterally move during biasing, 
other configurations which achieve the motion resistance of trolley 18 are 
possible. For example, a biasing device other than a compression spring 
may be used. Also, camming arm 75, or possibly adjustment plates 62, 64 in 
their entirety, could be slidably mounted with a spring or other bias 
mechanism in such as manner so as to serve as the compressing force behind 
rollers 82. 
Rigidly attached to camming arm 75 is a downwardly extending spring mount 
92. As shown in FIG. 5, extension spring 73 spans spring mount 92 and 
adjustment plate 62. Extension spring 73 biases camming arm 75 toward the 
wall extending direction, which is the direction of arrow 100. The tip of 
screw 71 serves as a stop member against which the surface of the camming 
arm tubing abuts. Rotation of stop screw 71 adjusts its height and thereby 
adjusts the camming alignment of camming arm 75. 
The anti-float apparatus of the present invention will be further 
understood in view of the following explanation of its installation and 
operation. Anti-float apparatus 40 is installed by positioning the 
separate mounting brackets halves 42, 44 along track 20, aligning angled 
coupling flanges 46, 48, and coupling the brackets together with bolts 49 
and nuts 50 as shown. With screws 52, 54 retracted, anti-float apparatus 
40 can be slid along track 20, either toward or away from the partition 
stacking area, into a proper longitudinal position for operation. Screws 
52, 54 are then tightened. It will be appreciated that the use of bracket 
halves, rather than a continuous bracket which slides onto track 20 during 
track installation, allows anti-float apparatus 40 to be readily removed 
if desired. 
Adjustment plates 62, 64, which may be coupled to bracket halves 42, 44 
during their installation, are then secured in a proper position. In 
particular, while screws 59 are loosened, slots 66 permit adjustment 
plates 62, 64 to be laterally shifted, i.e. to the left or right in FIG. 
2. This shifting allows for accommodation of trolleys with different 
thickness plates or different designs, such as found in some eight wheel 
trolleys. When adjustment plates 62, 64 have been positioned such that an 
appropriately sized gap or passageway 95 (See FIG. 5) for trolley 18 has 
been formed between the trolley engaging surfaces 90 of rollers 82 at a 
location centered below track channel opening 22, screws 59 are tightened 
to restrict further plate motion. Passageway 95, for the illustrated 
embodiment, is slightly more narrow than the uniform thickness of flat 
plate 26 at the height of cam rollers 82. It will be appreciated that it 
is within the scope of the invention to instead form passageway 95 more 
narrow than a lateral projection or a projecting region of trolley 18. In 
addition, cam rollers 82 could be positioned in contact with one another 
when trolley 18 is not passing therebetween and still define passageway 95 
as used herein. 
When adjustment plates 62, 64 are installed, camming arms 75 are preferably 
aligned with their rollered ends slightly angled away from the stacking 
area, or in other words toward the direction in which operable partitions 
16 travel when being shifted to a wall forming position. Expressed 
alternatively, trolley engaging roller surfaces 90, relative to a line 
connecting the camming arm pivot points or spring pins 78 and which is 
shown as line 97 in FIG. 5, are away from the stacking area. Larger or 
smaller angles can be provided by rotating stop screw 71, which effects 
small adjustments to the width of passageway 95. 
The advantageous function of anti-float apparatus 40 occurs when, for 
example, operable partitions 16 are being moved from a stacked position to 
form a wall. As partitions 16 arranged in the stacked position move 
outward in the wall extending direction 100, their trolleys 18 
individually encounter anti-float apparatus 40. In particular, the leading 
edge of trolley plate 26 arrives at passageway 95 and abuts trolley 
engaging surfaces 90 of rollers 82. It will be appreciated by those of 
skill in the art that with minor modification, camming arms 75 or their 
equivalent could readily be arranged to engage a partition supporting 
trolley in a number of locations to resist its motion. As passageway 95 is 
more narrow than plate 26, further motion of trolley 18 in wall extending 
direction 100 is resisted. The presence of stop screws 71 prevents camming 
arms 75 from pivoting out of the way of trolley 18. In order for trolley 
18 to continue through passageway 95, trolley 18 must be pulled or 
otherwise driven with sufficient force to cause rollers 82 to engage the 
front edge of plate 26, more particularly ramp up the front edge of plate 
26, as plate 26 continues its motion away from the stacking area. During 
this engagement, trolleys 18 urge rollers 82 laterally outward within 
camming arms 75 as guided by slots 86 against the biasing forces provided 
by compression springs 88. The force needed to ramp rollers 82, which is a 
force needed to be overcome by trolley 18 in order to pass through 
passageway 95, can be adjusted, for example, by varying the static width 
of passageway 95 or by using different strength compression springs. As 
trolley 18 continues in direction 100, rollers 82 roll along and continue 
to apply a compressive force against the side faces of plate 26. It will 
be appreciated that if camming arms 75 are angled towards the stacking 
area, they may have a tendency to slightly splay open toward the stacking 
area and not adequately apply a compressive force to the trolley sides. In 
view of this operation, it will be appreciated that for trolleys 18 
encountering passageway 95 which are not experiencing pulling or driving 
forces in the wall extending direction, or in other words trolleys 18 
which have been moved into contact with rollers 82 due to floating of 
their suspended partitions 16, no further movement from the stacking area 
is permitted by apparatus 40. Only trolleys 18 purposely being forcefully 
moved in the wall extending direction move with sufficient force to 
overcome the biasing forces provided by compression springs 88, thereby 
urging rollers 82 laterally outward, such that trolley 18 can pass through 
apparatus 40. 
When operable partitions 16 are moved from an extended position to a 
stacked arrangement, anti-float apparatus preferably offers negligible 
resistance to this motion. In the preferred embodiment shown, as trolleys 
18 move toward the stacking area and enter passageway 95, plate 26 again 
engages by direct contact rollers 82. Instead of rollers 82 needing to be 
moved outward against compression springs 88, each camming arm 75 pivots 
toward the stacking area to a retracted alignment as shown in shadow in 
FIG. 5. When trolley 18 has passed, stretched extension springs 73 return 
camming arm 75 into contact with screws 71 in preparation for the passage 
of the next trolley 18. 
In addition to swinging camming arms 75 away from trolley 18 by way of 
engagement therebetween, limited or no resistance to trolley 18 can be 
provided in alternate ways. For instance, electro-mechanical constructions 
including solenoid devices could be used to laterally retract or otherwise 
move camming arms 75, and more particular its trolley engaging surfaces, 
during wall stacking operations. 
While this invention has been described as having a preferred design, the 
present invention may be further modified within the spirit and scope of 
this disclosure. For instance, rather than cooperating with trolley 18 
directly below track 20, camming arms 75 or their equivalent could be 
positioned to engage the trolley shaft or perhaps even the trolley portion 
running inside track 20. This application is therefore intended to cover 
any variations, uses, or adaptations of the invention using its general 
principles. Further, this application is intended to cover such departures 
from the present disclosure as come within known or customary practice in 
the art to which this invention pertains.