Note: Descriptions are shown in the official language in which they were submitted.
CA 02234082 1998-04-06
Title: Apparatus for supporting modular furniture.
Back~~round of the Invention.
l.Field of the Invention
The present invention relates to apparatus for supporting
modular furniture of the type used in offices. The apparatus is
used in association with lifting means to allow access to an
office floor, e.g. for replacement of carpets or other
flooring, including panels of raised flooring, without the need
to remove the furniture from the office.
2.Prior Art
Modern offices are often provided with so-called "modular
furniture", which comprises an arrangement of panels
interconnected at angles to form office dividers, and which
have so-called "hanging tracks" used to support desks,
bookshelves, and other necessary office equipment. These
hanging tracks are vertical metal strips, usually located near
the edges of the panels, having a series of undercut slots from
which special hangers, with suitable hooks, can be suspended.
Generally, these hanging tracks are aligned with feet which
support the panels, and which usually provide the only contact
between the floor and the modular furniture.
The fact that quite a number of such panels, and their
associated desks and shelves, are connected together makes it
time consuming and costly to dismantle this furniture and
remove it from an office to allow carpeting or other flooring
to be replaced. Accordingly, apparatus has been designed and
used which will allow the panels and associated furniture to be
temporarily raised so that new flooring can be placed
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CA 02234082 1998-04-06
underneath. Apparatus of this kind is described, for example,
in:
U.S.Pat.No. 5,261,643, issued Nov.16,1993 to Wurdack;
U.S.Pat.No. 5,299,779, issued Apr.5,1994 to Collins;
U.S.Pat.No. 5,385,335, issued Jan.31,1995 to Wurdack;
U.S.Pat.No. 5,490,757, issued Feb.13,1996 to Stratman;
U.S.Pat.No. 5,529,287, issued Jun.25,1996 to Pelosi, Jr.
et al.; and
U.S.Pat.No. 5,628,610, issued May 13,1997 to Stratman et
al.
Several of these patents use lifting jigs which have
plates with a series of hooks for engaging the hanging tracks
of the panels; for example the Wurdack patents, and those of
Stratman and Pelosi et al. have this feature. Another lifting
device, and one which has more stability than the prior
devices, is described in Applicant's co-pending Canadian Patent
Application No.2,223,736, filed Feb.18,1998. This lifts the
panels by engaging their undersides, near to the legs, and thus
avoids applying upwards force to the hanging tracks, since in
some makes of panel such forces may cause the hanging tracks to
be dislocated.
Another shortcoming of the previously patented
arrangements is that it is difficult or impossible to place
carpeting underneath the leg of a panel, since this is usually
where the lifting device is positioned. Some installers simply
accommodate the panel leg and/or the lifting device by cutting
out a portion of the carpet or carpet tile, or slitting this
around the leg. In our co-pending Canadian patent application
aforesaid, a bridge member is provided having feet which can be
placed at either side of a leg, and the bridge member carries
a saddle member with auxiliary jacking means which can be used
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CA 02234082 1998-12-18
to lift the leg portion of a panel while leaving a clear space
under the leg area where reflooring can be done. This bridge is
good for spanning a space 3 feet or possibly 4 feet wide, and
is suitable particularly where the flooring is supplied in the
form of carpet tiles.
However, if it is desired to install strips of carpeting
supplied in rolls, there is often a need for providing a clear
space under aligned panels of more than 4 feet width, and
sometimes more than 6 feet width, which requires a larger
bridge than in the system described in our copending
application. Another limitation of this system is that in many
cases the low or "floor level" bridge described in our
copending application would meet interference from other panels
connected at right angles to the panels being lifted by the
bridge system. The present invention provides a system which
includes both a provision for a greater width of clear space,
suitable in the preferred form for installation of a 6 foot
wide carpet strip, and also provides a system in which bridge
members used to support the lifting means can be high enough
not to interfere with connected panels.
Sum~ary of the Invention
In accordance with one aspect of the invention,
apparatus for supporting modular furniture, including panels,
to allow access to a floor for reflooring or the like, and in
which the apparatus is suitable for supporting a panel end
while providing a clear space under the panel end, comprises:
a bridge member capable of spanning a distance of several
feet;
end supports including posts engageable with outer end
portions of the bridge member for supporting the bridge member
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clear of the floor,
a carrier slidable horizontally on said bridge member
between its end portions;
load carrying means held by the carrier for supporting a
lifting jig engaged with the panel end, the load carrying means
including means for applying upwards force to the lifting jig
so that the panel end may be supported while allowing access to
a floor area between the supports.
The reference to the "panel end" and similar references
will be understood to mean the end portion of a panel, since
the hanging tracks and legs are not strictly at the ends but
are close to the ends of the panels.
The lifting jig may be substantially the same as that of
my copending application, and is preferably such as to apply
lifting force to the underside a panel end around or near to a
panel leg, while an upper portion of the lifting jig is
attached to a hanging track of the panel end.
The bridge member may be a high or overhead type, being
above the tops of panels being supported. Alternatively, in
suitable circumstances, a low or "floor level" bridge member
may be used, of similar height to those shown in our aforesaid
copending application.
In the case of an overhead or high bridge member, the load
carrying means preferably includes a flexible webbing strap,
and the force applying means may include a winding spool
mounted on the carrier and holding the upper end of the strap,
and having a handle and a ratchet and pawl arrangement which
normally prevents unwinding. In the case of a low, floor level
bridge member, the load carrying means preferably engages the
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underside of a lifting jig, and the force applying means may
include auxiliary jacking means carried by the carrier.
For the overhead bridge member, each end support may
include a post of sufficient length to hold the bridge member
above tops of the panels; this allows the bridge member to
extend over other panels which may be joined to the panel or
panels engaged by the lifting jig. The posts may be supported
from the floor, on opposite sides of a panel, in which case the
posts preferably hold the bridge member at least 50 or 66
inches from the floor. Alternatively, support posts for the
overhead bridge member may be mounted on hanger brackets which
are supported by hanging tracks at the ends of two panels of an
aligned pair of panels, the suspension means being connected
between the bridge member and a lifting jig which supports the
central adjoining ends of the two panels.
The invention further provides a method of lifting modular
furniture including panels having accessory hanging tracks to
allow access to a floor for reflooring or the like, comprising:
connecting a lifting jig to one hanging track of a panel
end, and using jacking means and a floor mounted vertical shaft
to raise the lifting jig along said shaft to lift the panel
end;
positioning a bridge member adjacent to said one hanging
track, the bridge member having end supports for supporting the
bridge member above the floor,
slidably positioning a carrier on said bridge member, said
carrier having load carrying means, and using said load
carrying means to support said lifting jig and thereby to
support the panel end; and
lifting or removing said shaft to provide access to a
floor area under the bridge member and between said end supports.
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Brief Description of the Drawing~ss
Preferred embodiments of the invention will now be
described by way of example with reference to the accompanying
drawings, in which;
Fig.l is a perspective view of two office cubicles formed
by panels of the type which normally support modular furniture,
and show lifting means both in accordance with this invention
and the invention described in our aforesaid copending
application;
Fig.2 is an elevational view on lines 2-2 of Fig. l,
showing the type of lifting apparatus of our copending
application;
Fig.3 is an enlarged sectional view of part of the lifting
apparatus of Fig.2;
Fig.4 is a perspective view of the overhead bridge type
lifting apparatus in accordance with this invention,
Fig.5 is an enlarged view of a part of the apparatus of
Fig.4;
Fig.6 is a view of apparatus similar to that of Fig.4
being used in a different way;
Fig.7 is a detailed view of a base part for the apparatus
shown in Figs.4 and 6;
Fig.8 is a perspective view of another arrangement of
lifting means in accordance With this invention being used to
lift two aligned panels;
Fig.9 is a view of a part of the apparatus shown in Fig.8;
Fig.lO is a perspective view of another form of lifting
apparatus in accordance with this invention;
Fig.ll is a perspective view of a yet another embodiment
of the invention;
Fig. l2 is a detailed view of part of the apparatus shown
in Fig.ll, and
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Fig. l3 is a view of the apparatus of Fig.ll when the load
carrying means is fully in position.
Detailed Description.
Referring to Fig. l, this shows an arrangement of panels
Pa, Pb, etc. forming two cubicle-type offices. The panels would
normally have desks and other items of modular furniture
attached to them, but such items are omitted for simplicity.
Each panel has a hanging track 10 adjacent and parallel to an
outer edge, each track having a series of elongated apertures,
and each track is approximately aligned with a leg 12. In the
arrangement shown in the drawing lifting devices L are
positioned for lifting the ends of the panels, so that a11
panels can be lifted substantially simultaneously to avoid
straining the panels.
Fig.l shows simple lifting means L which are initially
used at the ends of almost all the panels, but some of these
are partially replaced with bridge type apparatus in accordance
with this invention depending on where a particular carpet
strip C is to be laid. These simple lifting means L are the
same as shown and described in our aforesaid copending
application, but are described herein, and shown in detail in
Figs 2 and 3, since the lifting jig parts of these lifting
means are also used in the bridge type apparatus of the present
invention.
As shown in Figs.2 and 3, each lifting means has a support
including a shaft 14 which normally extends vertically, and
which has a square section. The side of the shaft opposite the
panel or panels, hereinafter referred to as the rear side, is
provided with a rack 16 of ratchet type teeth having
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substantially horizontal upper surfaces. Slidable on the shaft
14 is a square-sectioned sleeve 20 which closely surrounds the
shaft and which is part of a lifting jig indicated generally at
22. Walls 24 extending rearwardly from opposite sides of the
sleeve 20 have horizontally elongated slots 25 which provide
guides for the ends of a pair of slidable horizontal pins 26
which support a pawl 27 located between the walls 24. The outer
ends of the pins 26 are connected together outside the walls 24
by spacer plates 28. The pawl 27 is movable within an aperture
20a in the rear of the sleeve 20, and has a series of teeth
which, as best seen in Fig.3, are complementary to those of the
rack 16 and are caused to engage those teeth by the action of
compression spring 30 acting between the rear of the pawl 27
and a back wall 31 joining the rear ends of the walls. The pawl
27 is movable to release the rack by a rod 32 threaded into the
pawl and passing along the center of the spring 30 and through
apertures in wall 31 in a pawl retracting lever 33, and which
terminates in a pawl retracting wing screw 34. The lever 33 can
be manually pivoted away from the wall 31 to pull the rod 32 so
as to release the pawl from the rack 16.
Referring to Fig.2, this shows the lifting jig 22 being
used to lift and support the junction of the adjacent panels Pi
and Pj, each having a hanging track 10 at its adjoining edges
with a series of elongated apertures 11. Fig.3 shows that the
front side of the sleeve 20 carries a spacer mounting plate 35
to which is attached, by screws 36, a square sectioned main
bracket support 37 which carries the panel engaging parts of
the lifting jig 22. These parts include a boot support plate 38
and an undercut hook member 40. The plate 38 has an outer
upturned retaining lip 42, and is carried by a boot sleeve 44
having an upwardly open recess fitting onto the lower end of
the main bracket support 37. The boot sleeve is adjustably held
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in place by a screw stud 46a and nut 46b, the screw stud
fitting into a threaded bore in the bottom end of support 37.
A boot brace plate 47 underlies and reinforces the connection
between the plate 38 and the boot sleeve 44. The hook 40 is
formed in a projecting flange 48a of a plate member 48 which
also has a right-angled flange 48b which lies against the front
side of the support 37 and which has three laterally elongated
slots which receive screws 49 attaching the plate member to the
support 37. These slots allow adjustment of the lateral
position of the hook 40 relative to the support plate 38. As
shown, the undercut hook 40 provides a downwardly facing recess
which is capable of engaging on the lower edge of a panel
aperture 11, while the support plate 38 engages the lower edge
of the same panel, as shown in Fig.l. The nut 46b allows the
plate 38 to be raised so that the panel is positively gripped
between the hook recess and the plate.
As seen in Fig.3, the lifting jig 22 also includes an
abutment or support plate 50, held by the lower edges of the
walls 24, from which projects a short cylindrical tube 51 which
provides a jack piston retainer for the movable part or
"piston" of removable jacking means 52, as shown in Fig.3; it
can also be used to locate the piston of a hydraulic jack. The
jacking means has a lower, relatively fixed, piston casing 54
the sides of which are supported by a toothed pawl or gripper
block 55 capable of engaging on the rack 16 below the sleeve
20. The piston casing slidably holds a piston 58 movable
relative to the casing by a jack handle 60. The handle is
connected to the lower end of the piston 58 by a cross pin 61
which is movable in vertically elongated slots in the sides of
the casing, and the handle 60 also has connection to the casing
provided by side links 62 which extend between a holding cross
pin 63 near the handle lower end and a similar pin 64 fixed
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across the lower end of the casing and which also holds the
gripper block 55 in the casing. With this arrangement,
downwards movement of the handle 60 pushes up the piston 58 and
thus raises the whole jig and panel part carried thereby by an
amount equivalent to several teeth of the rack 16.
Turning now to the bridge arrangement of this invention,
and especially the overhead bridge arrangement, Fig.4 shows a
supporting bridge which can be used to support the end of panel
Pa, and which is also used to support the junction of panels Pf
and Pg, while providing a clear space under the panel end to
allow reflooring. This arrangement includes a bridge member 80
in the form of an I beam of slightly more than 6 foot length,
supported near to its ends by brackets 81 fixed to the upper
ends of floor supported posts 82 formed of square steel tubing.
The posts are high enough to hold the bridge above the tops of
the panels which range in height from 36 to 96 inches.
Typically, the posts are high enough to hold the member 80 at
least 50 or 66 inches above floor level. The lower end of each
post is received in a square-sectioned socket 83 which is part
of base 84 and which protrudes perpendicularly from a square
steel plate 85. These parts provide a removable base for the
post 82 with a measure of stability. It is a feature of the
base 84 that it has a secondary socket 86 with its side welded
parallel to the plate 85. This can be used as an alternative to
the socket 82 where it is required to place a post very close
to a wall, as will be described with reference to Fig.6.
As shown in more detail in Fig.5, the lower flange of
bridge member 80 supports a carrier 90, slidable along the
bridge member for adjustment of its position, and having
inturned flanges 91 which engage the bridge member 80, and side
plates 92 which between them support a winding spool formed by
CA 02234082 1998-12-18
a slotted portion of a shaft 94 having an outer end suitably
shaped for receiving a handle 95. The plates 92 also support a
pawl 96 held by spring 97 against a ratchet wheel 98 fixed to
the shaft 94. The winding spool holds a webbing strap l00,
which surrounds and conceals it in Fig.5. This arrangement
allows the webbing strap to be wound onto the winding spool by
operation of the handle 95, while the pawl 96 prevents
unwinding until manually disengaged.
The lower end of the strap 100 is secured to the top of a
connector 102 formed of bent steel rod which has a hook-like
lower end 102a which fits under the spacer mounting plate 35 of
a lifting jig 22', similar to that shown in Fig.3, and which
provides load carrying means to support the panel end of ter the
shaft 14 has been raised or removed. The position which the
hook-like lower end 102a would occupy in relation to the
lifting jig is illustrated in broken lines in Fig.3. The
winding spool, ratchet and handle arrangement provides
tensioning means for the strap l00; this is similar to
tensioning devices used to tighten webbing straps around truck
loads. The winding spool provides enough rotation to allow the
length of the suspended strap to be adjusted to different
lifting jig heights. In addition, it allows the strap to be
wound in by an amount required to transfer load from a shaft 14
supporting the lifting device L to the bridge member, for which
a movement of 0.5 to 1.0 inches is sufficient. In the position
shown in Fig.4, the load has been transferred to the bridge
member and the shaft 14 has been lifted to allow positioning of
a carpet strip.
It may be noted that while the bridge 80 and other parts
are only required to support the end of one panel Pa in the
arrangement shown in Fig.4, nevertheless these parts will more
commonly be used to support the attached ends of two panels, as
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shown in relation to panels Pf and Pg, or three panel ends
where a third panel is connected to the junction of the two
panels, as for example at the junction of panels Pc, Pd, and Pf
in Fig. 1. On occasion the bridge member may be used to support
four panel ends at a point where four panels are connected
together. Each panel with attached desks may weigh several
hundred pounds, and in practice the bridge member should be
able to support, at its center, a weight of 1,500 pounds, and
preferably of at least 2,500 pounds.
It may also be noted that it is not essential that a strap
forms the suspension means, and that this could be a metal rod.
A strap is preferred, however, since it cannot scratch
furniture.
Fig.6 shows the same apparatus of Figs.4 and 5 being used
in a different way, where it is required to place a 6 foot wide
carpet strip C against a wall W and also under the end of panel
Pa of Fig.l. Here the base 84 is used with its plate 85
vertical and parallel and close to the wall, with the post 82
inserted into the secondary socket 86. Also, the top bracket 81
of the post is replaced at the wall end by a modified bracket
81' which has a closed end to prevent contact between the
bridge member and the wall. The carrier 90 is also of course
moved to a different position on bridge member 80.
Fig.7 shows further details of the base 84 The secondary
socket 86 is welded along the length of the plate 85 and has a
closed end, and the socket 83, while still projecting
perpendicularly relative to the plate, has its lower end welded
to the center of the socket 86. The sockets of this base 84 are
provided with transverse apertures for a cross pin 87, which
can be retained by cotter pin 88, and which passes through
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transverse bores 89 in the lower end of each post 82.
Fig.8 shows a variation of the apparatus of this invention
which can be used when it is desired to lift two aligned panels
in such a way that flooring can be fitted under the legs of the
adjoining panel ends. Here, the outer ends of the two panels Px
and Py, and the adjoining ends of the two panels, are initially
lifted by the simple lifting devices L1, L2, L3 identical to
the lifting means L shown in Figs.2 and 3, and it is required
to fit carpeting under lifting device L2.
This apparatus does not require posts which extend between
the floor and the bridge member as previously described;
instead short posts 82' are each part of an assembly which
includes a hanging bracket 110 held onto the post by screws 49,
shown in Fig.9. Each bracket 110 has a series of hooks which
engage an outer end hanging track 10a. The upper end of each
post carries a bracket 81 identical to the bracket 81 of the
previous embodiment. The two brackets between them support a
horizontal bridge member 80 identical to that of the previous
embodiment, the posts 82' being of sufficient length that the
member 80 is held wholly above the tops of the panels. A
suitable length for the posts 82' is at least 20 inches. This
allows the system to be used where there is another panel which
might interfere, as for example when the system is being used
to lift the junctions of panels Pc, Pd, and Pf in Fig.l. In
this embodiment, the lifting means L1 and L3 are aligned with
the spines at the outer ends of the panels and these spines
transmit the lifting forces from the lifting means L1 and L3 to
the posts 82' and thus to the bridge member.
As in the previous embodiment the bridge member 80
supports a carrier 90 which holds a spool for a strap 100 the
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lower end of which has a hook like element 102 which fits under
part 35 of the central lifting jig 22'.
In operation, the lifting means L1, L2 and L3 are firstly
attached to the panel ends as shown, with a portion of each
hanging track 10a being firmly held between the plates 38 and
the hook portions 40 as described above. Similar devices are
situated a11 around a number of connected panels, and a11 the
panels and the attached fittings are lifted substantially
evenly. For reflooring, it is usually sufficient to lift the
panels only 1 or 1 1/2 inches.
When it has been determined that a carpet strip needs to
be positioned under the adjoining ends of the panels, the
hangers 110 are then engaged in the upper portions of the outer
hanging tracks 10a, and the bridge member 80 is located in the
brackets at the tops of the posts 82', with the carrier 90
located centrally of the bridge member. The hook element 102 is
then used to suspend the central lifting jig, the strap 100
being tensioned by handle 95 so that the weight of the
adjoining panels ends is transferred to the bridge member. The
shaft 14 of the central lifting means L2 can then be lifted or
removed, and a roll of carpeting C, typically 6 foot in width,
can be inserted under a row of the panels, for example as
illustrated in Fig. 1.
Depending on the load to be lifted, it may be possible to
use the apparatus of Fig.8 without first lifting with the
lifting devices L2, L3 and L4. Instead, the hanger and post
assemblies, and the bridge member, may be put into place before
any lifting occurs, and the central lifting jig may then be
suspended by the strap 100, suitable tension being applied by
handle 95. The shaft 14 of lifting device 14 is not required in
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this option. The pair of panels may then be lifted together by
operation of the lifting devices L1 and L3, with the strap and
bridge arrangement lifting the adjoining panel ends.
Fig.lO shows a floor level bridge apparatus closely
similar to that described in our copending application suitable
for lifting the adjoining ends of two panels while providing
free space under the panel ends. This includes a lifting jig
22", identical to jig 22 described above, but which is mounted
by means of a saddle l20 on a central portion of a bridge
member 121 which engages the floor by means of two spaced feet
122 which support threaded posts 123. Here the bridge is longer
than the similar apparatus described in my copending
application, being dimensioned so that the feet 122 are spaced
more than 6 feet apart.
Figs.ll-13 show a further version of a floor level bridge
arrangement, which operates more like the embodiments of
Figs.4-8 in that it may be used to support adjoining panel ends
which have previously been lifted by simple lifting means
indicated in Fig. l3 at L2, and which include a vertical shaft
14 and a lifting jig movable vertically on the shaft by jacking
means described above with reference to Fig.3. This apparatus
may be used where carpet strips such as C1, CZ, shown in Fig.ll,
have been laid in the vicinity of a lifting device, and where
it is desired to replace a strip C3 in the position occupied by
the lifting device L2.
As shown, the additional apparatus includes a bridge
assembly 170 having a bridge member 171 which comprises a
straight length of rectangular tubing or solid bar stock
supported by spaced apart feet 172 and posts 173 which are
adjustable in height and hold the bridge member l71 several
inches above the floor. The bridge member 171 is preferably
CA 02234082 1998-12-18
long enough that the feet 172 can be spaced far enough apart to
provide a clear working space of more than 6 feet between the
legs . On this bridge member is slidable a carrier 174 of saddle
form, i.e. with depending sides which contact the sides of the
bridge and hold it upright, and which carries an auxiliary load
carrying means 176. The load carrying means 176 includes a load
angle bracket 178 which can fit under the boot brace plate 47
to support the lifting jig 22, and also includes auxiliary
jacking means 180 for raising this bracket.
The auxiliary jacking means 180, best seen in Fig. l2,
includes a tubular sleeve post l82 braced by a gusset 183 to
the carrier 174, on which post is slidable an actuator cylinder
184 which carries the load angle bracket 178, and which has nut
185 welded to its upper end. This nut receives a height
adjustment screw 187 which extends down through the sleeve post
to engage the carrier at its lower end. The cylinder l84, along
with screw 187, can be raised by a lever 188 which has its
inner end pivoted at 189 to lever holding plates 190 welded to
the sides of the actuator cylinder, and which has a fulcrum
provided by a pivot pin 191 held by the top of a pivot bracket
192. The lower end portion of the bracket 192 is screw threaded
and engages an adjustment nut 194 held by a pivot sleeve 195
which receives the main threaded part of the bracket 192, and
which is connected to the carrier 174 by pivot pin 196 and
fixed pivot bracket 197.
In operation, the bridge member is positioned as shown
with its legs clear of the carpet strip C3 which is to be
replaced. The carrier 174 is moved from the position shown in
Fig.ll to that shown in Fig.l3 so as to be positioned with its
bracket 178 under the boot brace plate 47, and the auxiliary
jacking means is used to apply force to the boot brace plate so
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as to transfer the weight of the panel from the shaft 14 to the
bridge member. This involves firstly raising the actuator
cylinder 184 by rotation of the screw 187 until the bracket 178
is in contact with the boot brace plate, and then pushing down
lever l88 to raise the bracket 178 until this is taking the
full load of the panel. When the bridge is taking the full
load, screw 187 is tightened so that its lower end again
engages the bottom of the sleeve post 182 so as to hold the
bracket 178 in position, after which the handle 188 is
released. The shaft 14 can then be lifted or removed to allow
replacement of the strip C3.
17
